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  • Articles  (298)
  • Animals
  • Chemical Engineering
  • Electronic structure and strongly correlated systems
  • salinity
  • temperature
  • Springer  (298)
  • Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition  (240)
  • Geography  (31)
  • Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics  (23)
  • Architecture, Civil Engineering, Surveying  (6)
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  • Articles  (298)
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  • 1
    Electronic Resource
    Electronic Resource
    Successive Approximation Linear Quadratic Regulator for Estuarine Management Problem (2000)
    Springer
    Water resources management 14 (2000), S. 157-175 
    Details
    ISSN: 1573-1650
    Keywords: estuarine management ; fishery harvest ; freshwater inflow ; linear quadratic regulator ; salinity ; successive approximation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Geography
    Notes: Abstract A successive approximation linear quadratic regulator (SALQR)method is applied to solve estuarine management problems to determine the optimal amount of freshwater inflows into baysand estuaries to maximize fishery harvests. Fishery harvests areexpressed in regression equations as functions of freshwaterinflows. The optimization problem is posed as a discrete-timeoptimal control problem in which salinity represents the statevariable and freshwater inflow represents the control variable. A two-dimensional hydrodynamic-salinity transport model, HYD-SAL,is used as the transition to simulate the flow circulation andtemporal and spatial salinity pattern in an estuary system. Thebound constraints for the control and state variables areincorporated into the objective function using a penalty functionmethod to convert the problem into an unconstrained formulation. The SALQR method is applied to the Lavaca-Tres Palacios Estuaryin Texas and the results are compared with those of usingregression equations as the transition equations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026576129765
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  • 2
    Electronic Resource
    Electronic Resource
    The effect of seawater flow and temperature on metamorphosis and postlarval development in great scallop (2000)
    Springer
    Aquaculture international 8 (2000), S. 513-530 
    Details
    ISSN: 1573-143X
    Keywords: great scallop (Pecten maximus) ; hatchery ; metamorphosis ; seawater flow ; spat development ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Variations in growth and survival of hatchery-reared post-metamorphicjuveniles of great scallop Pecten maximus prompted anexamination of settlement and postlarval development. The effects ofseawater flow and temperature on great scallop metamorphosis andpostlarvae were studied over a 4–5 week period. In allexperiments, and regardless of environmental conditions, great scallopmetamorphosed after a 2–3 week period with values of 35 to70%. Subsequently, spat numbers increased slightly. Spatmortality generally occurred from the third week onward and reachedlevels as high as 30% by the fifth week under standardconditions. At 20 °C, however, 60% mortality levels wererecorded. Differences in spat growth rate, ranging from 37 to 45 μmday−1, were noticed at different seawater flow ratesbut no clear tendency could be discerned. Temperature affected spatgrowth with an increase in size from 24 μm day−1 at15 °C to 35 μm day−1 at 18 °C. Conversely,growth was suppressed at 20 °C (14 μm day−1).For optimal metamorphosis and postlarval development in great scallop, aseawater flow of 4.3 L h−1 per sieve and a temperatureof 15 °C are recommended.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009274707986
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  • 3
    Electronic Resource
    Electronic Resource
    Effect of Boron on the Structure and Composition of Cobalt Silicides (2000)
    Springer
    Powder metallurgy and metal ceramics 39 (2000), S. 599-602 
    Details
    ISSN: 1573-9066
    Keywords: solid-phase reaction ; solubility ; temperature ; cobalt silicides ; boron
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The system Co ― Si ― B is promising for development of new soft magnetic materials. We studied the effect of boron on the structure and composition of cobalt silicides during solid-phase reaction of powders of the starting components under a 3·10−3 Pa vacuum in the temperature range 200°C to 1300°C for boron content from 0.5 mass% to 7.7 mass% by differential thermal analysis, metallographic analysis, x-ray analysis, and electron-probe microanalysis. We established that boron is not soluble in cobalt silicides. Formation of ternary chemical compounds is typical for the Co ― Si ― B system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1011384332153
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  • 4
    Electronic Resource
    Electronic Resource
    Root-shoot interactions in mineral nutrition (2000)
    Springer
    Plant and soil 226 (2000), S. 57-69 
    Details
    ISSN: 1573-5036
    Keywords: ABA ; K/Na selectivity ; nitrate reduction ; nitrogen ; phloem ; phosphate ; root-shoot interactions ; salinity ; xylem
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract In this paper four classes of co-operative root-shoot interations are addressed. (I) Nitrogen concentrations in the xylem sap originating from the root and in the phloem sap as exported from source leaves are much lower than those required for growth by apices and developing organs. Enrichment of xylem sap N is achieved by xylem to xylem (X-X) transfer, by which reduced N, but not nitrate, is abstracted from the xylem of leaf traces and loaded into xylem vessels serving the shoot apex. Nitrogen enrichment of phloem sap from source leaves is enacted by transfer of reduced N from xylem to phloem (X-P transfer). Quantitative data for the extent of the contribution of X-X and X-P transfer to the nutrition of young organs of Ricinus communis L. and for their change with time are presented. (II) Shoot and root cooperate in nitrate reduction and assimilation. The partitioning of this process between shoot and root is shifted towards the root under conditions of nitrate- and K-deficiency and under salt stress, while P deficiency shifts nitrate reduction almost totally to the shoot. All four changes in partitioning can be attributed to the need for cation-anion balance during xylem transport and the change in electrical charge occurring with nitrate reduction. (III) Even maintenance of the specificity of ion uptake by the root may – in addition to its need for energy – require a shoot-root interaction. This is shown to be needed in the case of the maintenance of K/Na selectivity under the highly adverse condition of salt stress and absence of K supply from the soil. (IV) Hormonal root to shoot interactions are required in the whole plant for sensing mineral imbalances in the soil. This is shown and addressed for conditions of salt stress and of P deficiency, both of which lead to a strong ABA signalling from root to shoot but result in different patterns of response in the shoot.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026431408238
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  • 5
    Electronic Resource
    Electronic Resource
    Leachate from a Waste Disposal Centre reduces the initiation of arbuscular mycorrhiza, and spread of hyphae in soil (2000)
    Springer
    Plant and soil 227 (2000), S. 35-45 
    Details
    ISSN: 1573-5036
    Keywords: ammonia ; ammonium ; arbuscular mycorrhiza ; landfill ; leachate ; salinity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Irrigating arbuscular mycorrhizal plants with leachate from a waste disposal centre was examined in a set of experiments. Application of leachate at half the average concentration found in the field or higher reduced the growth of the host plant, the initiation of mycorrhizal colonisation, and hyphal growth of the mycorrhizal fungus Glomus pellucidum through the soil. Causes of these reductions are complex and interrelated, and associated with the electrical conductivity of the solution, toxicity of specific ions, in particular NH4 +, NH3 and HCO3 −, and changes in the pH causing shifts in the equilibria of the soil solution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026519527211
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  • 6
    Electronic Resource
    Electronic Resource
    The influence of temperature and nitrogen source on growth and nitrogen uptake of two polar-desert species, Saxifraga caespitosa and Cerastium alpinum (2000)
    Springer
    Plant and soil 227 (2000), S. 139-148 
    Details
    ISSN: 1573-5036
    Keywords: Arctic ; Cerastium alpinum ; nitrogen source ; nitrogen-uptake ; organic N ; polar-desert plants ; Saxifraga caespitosa ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Polar-desert plants experience low average air temperatures during their short growing season (4–8 °C mean July temperature). In addition, low availability of inorganic nitrogen in the soil may also limit plant growth. Our goals were to elucidate which N sources can be acquired by polar-desert plants, and how growth and N-uptake are affected by low growth temperatures. We compared rates of N-uptake and increases in mass and leaf area of two polar-desert species (Cerastium alpinum L. and Saxifraga caespitosa L.) over a period of 3 weeks when grown at two temperatures (6 °C vs. 15 °C) and supplied with either glycine, NH4 + or NO3 −. At 15 °C, plants at least doubled their leaf area, whereas there was no change in leaf area at 6 °C. Measured mean N-uptake rates varied between 0.5 nmol g−1 root DM s−1 on glycine at 15 °C and 7.5 nmol g−1 root DM s−1 on NH4 + at 15 °C. Uptake rates based upon increases in mass and tissue N concentrations showed that plants had a lower N-uptake rate at 6 °C, regardless of N source or species. We conclude that these polar-desert plants can use all three N sources to increase their leaf area and support flowering when grown at 15 °C. Based upon short-term (8 h) uptake experiments, we also conclude that the short-term capacity to take up inorganic or organic N is not reduced by low temperature (6 °C). However, net N-uptake integrated over a three-week period is severely reduced at 6 °C.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026528830228
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  • 7
    Electronic Resource
    Electronic Resource
    Leaf K/Na ratio predicts salinity induced yield loss in irrigated rice (2000)
    Springer
    Euphytica 113 (2000), S. 109-118 
    Details
    ISSN: 1573-5060
    Keywords: grain yield ; leaf K/Na ratio ; Oryza sativa ; salinity ; screening tools ; yield reduction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Salinity is a major constraint to irrigated rice production, particularly in semi-arid and arid climates. Irrigated rice is a well suited crop to controlling and even decreasing soil salinity, but rice is a salt-susceptible crop and yield losses due to salinity can be substantial. The objective of this study was to develop a highly predictive screening tool for the vegetative growth stage of rice to estimate salinity-induced yield losses. Twenty-one rice genotypes were grown over seven seasons in a field trials in Ndiaye, Senegal, between 1991 and 1995 and were subjected to irrigation with moderately saline water (3.5 mS cm-1, electrical conductivity) or irrigation with fresh water. Potassium/sodium ratios of the youngest three leaves (K/NaLeaves) were determined by flame photometry at the late vegetative stage. Grain yield was determined at maturity. All cultivars showed strong log-linear correlations between K/NaLeaves and grain yield, but intercept and slope of those correlations differed between seasons for a given genotype and between genotypes. The K/NaLeaves under salinity was related to grain yield under salinity relative to freshwater controls. There was a highly significant correlation (p 〈 0.001) between K/NaLeaves and salinity-induced grain yield reduction: the most susceptible cultivars had lowest K/NaLeaves and the strongest yield reductions. Although there were major differences in the effects of salinity on crops in both the hot dry season (HDS) and the wet season, the correlation was equally significant across cropping seasons. The earliest possible time to establish the relationship between K/NaLeaves under salinity and grain yield reduction due to salinity was investigated in an additional trial in the HDS 1998. About 60 days after sowing, salinity-induced yield loss could be predicted through K/NaLeaves with a high degree of confidence (p 〈 0.01). A screening system for salinity resistance of rice, particularly in arid and semi-arid climates, is proposed based on the correlation between K/NaLeaves under salinity and salinity-induced yield losses.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003981313160
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  • 8
    Electronic Resource
    Electronic Resource
    Modification of the response of saline stressed tomato plants by the correction of cation disorders (2000)
    Springer
    Plant growth regulation 30 (2000), S. 37-47 
    Details
    ISSN: 1573-5087
    Keywords: glucose phosphate synthase ; invertase ; mineral nutrition ; salinity ; water relations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The interactions between NaCl and other major nutrients have been generally observed in plants. Decreases of nutrient uptake under saline conditions normally appear in tomato plants grown under saline conditions. In this work, the effect of increased external Ca, K and Mg concentrations under saline conditions has been investigated. Tomato plants (Lycopersicon esculentum, Mill) were grown in a greenhouse, in 120 L capacity containers, filled with continuously aerated Hoagland nutrient solution. Treatments were added to observe the combined effect of two NaCl levels (30 and 60 mM) and three levels of Ca, K and Mg (in mM ratios of 4:6:1, 7:9:2 and 10:12:3; treatments C1, C2 and C3 respectively) on growth, fruit yield and water relations. Saline treatments decreased the growth, which was partly restored with the C2 treatment and totally with the C3 treatment. A good association was observed between the electric conductivity of the medium and the water or osmotic potential of the leaves, independent of the type of treatment (salinity or cation ratio). Salinity at 30 and 60 mM NaCl reduced the fruit yield compared with that obtained at 0 mM NaCl. However, there was an increase, as a consequence of the application of treatments C2 and C3, in each saline treatment. At a high salinity level (60 mM), the ratios Na/K, Na/Ca and Na/Mg in young leaves decreased as a consequence of cation treatments. Higher concentrations of sugars in leaves and fruits were obtained after increasing the salinity and cation concentrations. Also, sucrose phosphate synthase activity in leaves and fruits was increased after the treatments, but there was no measurable invertase activity in fruits. Therefore, the concentrations of Ca, K and Mg in the nutrient solution could be important factors in the hydroponic culture of tomato grown under saline conditions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006359503099
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  • 9
    Electronic Resource
    Electronic Resource
    Use of Electrical Conductivity Instead of Soluble Salts for Soil Salinity Monitoring in Central Asia (2000)
    Springer
    Irrigation and drainage systems 14 (2000), S. 199-206 
    Details
    ISSN: 1573-0654
    Keywords: salinity ; electrical conductivity ; laboratory ; data ; Central Asia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The USSR classifications of soil salinity used in Central Asiawas based on laboratory measurement of the total dissolved(toxic) salts or the chloride ion concentration in the soil waterextracts (soil:water = 1:5). Current practices, however, startto differ between the republics because of different levels ofacceptance of international literature. This change in practiceis triggered partly by the cost of the laboratory measurements.The use of different methods next to each other affects thereliability of information on salinity. This paper promotes theused of the UC of a 1:1 soil-water suspension was found to givethe best fit to the soil extract with leaching of calcium andsulfate ions. The cost of data collection is significantly lowerthan that of the 1:5 extract.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026560204665
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  • 10
    Electronic Resource
    Electronic Resource
    Revisiting the relationship between common weather variables and loblolly–shortleaf pine seed crops in natural stands (2000)
    Springer
    New forests 19 (2000), S. 187-204 
    Details
    ISSN: 1573-5095
    Keywords: Coastal Plain sites ; Pinus echinata Mill. ; P. taeda L. ; precipitation ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Seed production was monitored during24 years using seed-collection traps inloblolly–shortleaf pine (Pinus taeda L.–P.echinata Mill.) stands located in southeast Arkansas,north-central Louisiana, and southwest Mississippi onthe southeastern Coastal Plain, USA. Sound seedproduction was correlated with mean monthlyprecipitation and temperature from National Oceanicand Atmospheric Administration weather stationslocated near the seed-collection areas to determinethe potential of weather factors in forecasting pineseed crops. Correlations were restricted to threecritical periods in the pine reproductive cycle –strobili primordia differentiation, pollination, andfertilization. The most important (P ≤ 0.05)variables correlated with pine seed production for combined locations were cumulative precipitation (r = +0.60) during July, August, and September at 27 to 25 months before seed dispersal and mean temperature (r = −0.45) in August at 26 months before seed dispersal. Because multiple environmental factors can negatively impact pine seed development during the two yearsfollowing strobili primordia differentiation,seed-production forecasts based on weather variablesshould be verified by on-site cone counts during thesummer preceding autumn seed dispersal.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006624907975
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  • 11
    Electronic Resource
    Electronic Resource
    Salinity increases CO2 assimilation but reduces growth in field-grown, irrigated rice (2000)
    Springer
    Plant and soil 218 (2000), S. 1-10 
    Details
    ISSN: 1573-5036
    Keywords: dry matter reduction ; leaf chlorophyll content ; leaf sodium uptake ; Oryza sativa ; photosynthesis ; salinity ; season effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Salinity is a major yield-reducing factor in coastal and arid, irrigated rice production systems. Salt tolerance is a major breeding objective. Three rice cultivars with different levels of salt tolerance were studied in the field for growth, sodium uptake, leaf chlorophyll content, specific leaf area (SLA), sodium concentration and leaf CO2 exchange rates (CER) at photosynthetic active radiation (PAR)-saturation. Plants were grown in Ndiaye, Senegal, at a research station of the West Africa Rice Development Association (WARDA), during the hot dry season (HDS) and the wet season (WS) 1994 under irrigation with fresh or saline water (flood water electrical conductivity = 3.5 mS cm-1). Relative leaf chlorophyll content (SPAD method) and root, stem, leaf blade and panicle dry weight were measured at weekly intervals throughout both seasons. Specific leaf area was measured on eight dates, and CER and leaf sodium content were measured at mid-season on the first (topmost) and second leaf. Salinity reduced yields to nearly zero and dry-matter accumulation by 90% for the susceptible cultivar in the HDS, but increased leaf chlorophyll content and CER at PAR- saturation. The increase in CER, which was also observed in the other cultivars and seasons, was explained by a combination of two hypotheses: leaf chlorophyll content was limited by the available N resources in controls, but not in salt-stressed plants; and the sodium concentrations were not high enough to cause early leaf senescence and chlorophyll degradation. The growth reductions were attributed to loss of assimilates (mechanisms unknown) that must have occurred after export from the sites of assimilation. The apparent, recurrent losses of assimilates, which were between 8% and 49% according to simulation with the crop model for potential yields in irrigated rice, ORYZA S, might be partly due to root decomposition and exudation. Possibly more importantly, energy-consuming processes, such as osmoregulation, interception of sodium and potassium from the transpiration stream in leaf sheaths and their subsequent storage, drained the assimilate supply.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1014953504021
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  • 12
    Electronic Resource
    Electronic Resource
    Leaf development, transpiration and ion uptake and distribution in sugarcane cultivars grown under salinity (2000)
    Springer
    Plant and soil 218 (2000), S. 59-69 
    Details
    ISSN: 1573-5036
    Keywords: growth ; ion-uptake ; salinity ; salt tolerance ; sugarcane ; transpiration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The effects of salinity on leaf growth, initiation and senescence, on transpiration rates, on leaf water potential and on uptake and distribution of several ions were studied in two sugarcane cultivars differing in salinity sensitivity. Plants, growing in a growing mixture in pots, were exposed to salinized irrigation water for 68 days, starting 60 days after planting. EC values of the irrigation water were 1.0, 2.0, 4.0, 8.0 and 12 dS/m, obtained by using a mixture of NaCl and CaCl2. Plants were also grown in nutrient solution and were at a similar age when exposed to a salinity level of 3 dS/m for 30 days followed by 6.0 dS/m for an additional 30 days. Two Na:Ca ratios of 18:1 and 1:2 were used for salinization of the nutrient solution. Both leaf dry weight and area decreased with increasing salinity, but in the more salinity tolerant cultivar H69-8235, the decrease was moderate. Salinity hardly reduced average area per leaf in H69-8235, while the number of leaves declined sharply. This decline was caused by enhanced senescence of mature leaves and not by a decreased rate of leaf initiation. In the more sensitive cultivar, H65-7052, leaf area and initiation of new leaves were sharply reduced by salinity while leaf senescence was less affected. Leaf water potential decreased during the early stages of salinity exposure, and the reduction in water potential was larger in H69-8235. Salinity also decreased the rate of transpiration rate but to a lesser extent than leaf development and growth. The accumulation of Cl and Na in the TVD (top visible dewlap) leaf of the tolerant cultivar H69-8235 was greater than in the sensitive cultivar H65-7052. The concentration of Cl in the TVD leaf was more than 10 times that of Na in both cultivars. The concentration of both ions, but not of K, increased during the early stages of salinity exposure and then remained constant. A gradient in concentration of Cl and Na over the plant was found in both cultivars at all salinity levels, and was steepest between the TVD and younger leaves. No specific Na effect on leaf growth or transpiration could be detected. The accumulation of Cl and Na but not of K occurred primarily in the roots rather than in the leaves and stalks.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1014996229436
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  • 13
    Electronic Resource
    Electronic Resource
    Phenotypic characteristics of root-nodulating bacteria isolated from Acacia spp. grown in Libya (2000)
    Springer
    Plant and soil 224 (2000), S. 171-183 
    Details
    ISSN: 1573-5036
    Keywords: Acacia ; Libya ; root-nodulating bacteria ; salinity ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Thirty isolates of root-nodulating bacteria obtained from Acacia cyanophylla, A. karroo, A. cyclops, A. tortilis (subsp.raddiana), Faidherbia albida and Acacia sp., grown in different regions of Libya, were studied by performing numerical analysis of 104 characteristics. Three fast- and one slow-growing reference strains from herbaceous and woody legumes were included. Five distinct clusters were formed. The fast-growing reference strains were separated from the isolates whereas the slow-growing was included in cluster 4. With the exception of one cluster, the majority of clusters were formed regardless of the host plant or site of origin. Based on plant tests, generation times, acid production and carbon utilization the isolates were diverse (fast and slow-growing isolates). Like slow-growing isolates, most of the fast-growing isolates appeared to be non-specific, nodulated many species from the same genus notably F. albida, known to nodulate only with slow-growing strains. Most clusters grew at temperatures 35 °C and 37 °C; some grew at temperatures above 40 °C. The majority of isolates grew at acid and alkaline pH and only one isolate grew below pH 4. Most isolates were able to utilize many amino acids as nitrogen sources and to reduce nitrate. Urea was hydrolysed by all clusters. Monosaccharides and polyols were used by slow and fast-growing isolates as the only carbon sources whereas assimilation of disaccharides varied: Some isolates, like slow-growing isolates, failed to utilize these carbon sources. Most isolates were unable to utilize polysaccharides. Regarding tolerance to NaCl on agar medium, the majority of isolates were unable to grow at a concentration of 2% NaCl, but some were highly resistant and there was one isolate which grew at 8% NaCl. Most isolates were resistant to heavy metals and to antibiotics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004838218642
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  • 14
    Electronic Resource
    Electronic Resource
    Dynamics of the Subsurface Temperature Field Caused by Mining-Related Groundwater Management (2000)
    Springer
    Studia geophysica et geodaetica 44 (2000), S. 442-459 
    Details
    ISSN: 1573-1626
    Keywords: temperature ; groundwater ; sedimentary basin ; exploitation ; transient effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Geosciences , Physics
    Notes: Abstract The subsurface temperature field was studied on a set of 46 borehole logs measured in the vicinity of uranium deposits in the Bohemian Cretaceous Basin. Vertical variations of the steady state temperature and the temperature gradient are governed by thermal conductivity which strongly varies in dependence on lithology. Large departures from undisturbed temperature detected in many holes are associated with uranium mining. A positive anomaly is observed in leaching fields where large amounts of acid are injected into the uranium-bearing Cenomanian. A negative anomaly is linked to the operation of hydraulic barriers which enclose the mining area and helps to contain pollution by pumping clean water into the Cenomanian aquifer. The spatial distribution of the observed temperature anomalies helps to map the migration of the fluids used in both processes. The temperature disturbance is propagated from the Cenomanian aquifer up through overlying impermeable sediments. The good fit of transient conductive models to the measured temperatures rules out heat advection and hence upward water flow towards and contamination of the upper Middle Turonian aquifer in the vicinity of the holes studied.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1022168705973
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  • 15
    Electronic Resource
    Electronic Resource
    Magnéli phases of anion-deficient rutile as lubricious oxides. Part I. Tribological behavior of single-crystal and polycrystalline rutile (Ti n O2n−1) (2000)
    Springer
    Tribology letters 8 (2000), S. 65-78 
    Details
    ISSN: 1573-2711
    Keywords: solid lubricants ; lubricious oxides ; TiO2 ; rutile ; oxygen stoichiometry ; Magnéli phases ; tribometry ; friction ; wear ; shear strength ; temperature ; atmosphere ; extreme environment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract In part I of this paper series, wide temperature range SEM-tribometric results generated in vacuum and various partial pressures of oxygen are combined with relevant literature data to examine a hypothesis correlating the oxygen stoichiometry of the Ti n O2n−1 Magnéli phases of the rutile polymorph of titania with their tribological behavior. Single-crystal and polycrystalline rutile specimens of narrow stoichiometry ranges were sliding against α-SiC and themselves. The surface shear strength changes were determined as a function of the thermal–atmospheric test environment, and the shear strength values were estimated by the coefficients of friction, the real area of contact and the published yield strength of rutile. The data appear to be sufficient and sufficiently reliable to confirm the accuracy of the hypothesis. The tendency of the rutile stoichiometry (ergo the friction) to shift as a function of temperature and partial pressure of oxygen causes this material to be thermo-oxidatively unstable for tribological applications in extreme environments. In part II, a study is described to formulate oxidatively more stable Magnéli phases by Cu-doping, and test the new materials by SEM tribometry using a procedure used for pure rutile here in part I. By employing this doping methodology similar to creating high-temperature superconductive oxides in part II, some feasibility of producing oxidatively stable, lubricious oxides with acceptably low wear rates is indicated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1019122915441
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  • 16
    Electronic Resource
    Electronic Resource
    FTIR spectroscopy and nanotribological comparative studies: influence of the adsorbed water layers on the tribological behaviour (2000)
    Springer
    Tribology letters 9 (2000), S. 111-117 
    Details
    ISSN: 1573-2711
    Keywords: AFM ; force ; friction ; adhesion ; molecular water layer ; temperature ; capillary forces ; PMIRRAS
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Under ambient conditions, a water film is always present on a silica substrate and generates additional capillary forces between the nanotip and the studied surface. In the present paper, we report AFM measurements of pull-off and friction forces as a function of the temperature and a comparative FTIR spectroscopy study. The AFM results show a net decrease of the forces as the temperature increases, while the IR spectroscopy indicates that the liquid film is removed at high temperature. Consequently, we deduce that a liquid neck is created between the tip and the surface and that the forces measured are mostly capillary forces. The present work shows that temperature studies with AFM can be a useful way to probe the influence of the capillary force in turn to characterize surface properties.
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    URL: http://dx.doi.org/10.1023/A:1018868830205
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    Magnéli phases of anion-deficient rutile as lubricious oxides. Part II. Tribological behavior of Cu-doped polycrystalline rutile (Ti n O2n−1) (2000)
    Springer
    Tribology letters 8 (2000), S. 79-96 
    Details
    ISSN: 1573-2711
    Keywords: solid lubricants ; lubricious oxides ; TiO2 ; rutile ; oxygen stoichiometry ; Magnéli phases ; tribometry ; friction ; wear ; shear strength ; temperature ; atmosphere ; extreme environment ; molecular engineering ; cation doping ; aliovalency
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract As a follow-up to the work described in part I of this paper series, a preliminary study was conducted with polycrystalline rutile TiO−x to render its friction and wear performance independent of the environment. The main goal was to confine the most tribologically desirable oxygen stoichiometries of the crystallographic shear-induced Magnéli phases (CSMP) of rutile by doping with cations similar in size and polarizability to the Ti4+, but with lower valences. The resultant chemical expulsion of oxygen from the rutile lattice was intended to generate CSMP free of friction and wear variations caused by changes in the thermal–atmospheric environment. Copper, iron, cobalt and nickel ions were tried as dopants introduced as their stable oxides via a simple ball-milling, hot-pressing and annealing procedure, but only a (Ti + Cu)O1.80 model blend resulted in a desired reaction. A portion of the copper entered the lattice to form a new titanium–copper CSMP, resembling the well-known V3Ti6O17 catalyst equivalent to an undoped rutile CSMP with an O/Ti ratio of 1.89. Although the shear behavior of this new, wear-resistant compound was in accordance with predictions, its friction is higher and more variable than desired for a wide environmental regime lubricant. The preparation technique was only sufficient to demonstrate that oxygen vacancy-induced creation of low-friction CSMP may be possible by doping; it does not appear to be useful for formulating practical, rutile-based lubricious oxides.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1019174932279
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  • 18
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    Characteristics of Pestalotiopsis Associated with Hardy Ornamental Plants in the UK (2000)
    Springer
    European journal of plant pathology 106 (2000), S. 77-85 
    Details
    ISSN: 1573-8469
    Keywords: Pestalotiopsis sydowiana ; morphology ; pathogenicity ; ericaceous plants ; conifers ; temperature ; pH ; water potential
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Pestalotiopsis isolates obtained from the foliage, stem-base and roots of hardy ornamentals grown on commercial nurseries in the UK were identified and characterised according to pathogenicity and colony morphology. All 18 isolates were identified as Pestalotiopsis sydowiana on the basis of conidia morphology, and confirmation of identification was made by experts at CABI Bioscience. Isolates were pathogenic on the host from which originally isolated. Typical symptoms included foliar browning of foliage and stems, and the presence of black or greenish-black acervuli on diseased tissue. Isolates were not host specific and infected other species of hardy ornamentals. Three colony types on potato dextrose agar were distinguished according to colour and production of acervuli by individual isolates. Three selected isolates of P. sydowiana were characterised by examining the effects of growth media, temperature, pH, and water potential on hyphal extension. Isolates grew well on commonly used growth media, including PDA, Sabouraud dextrose agar (SDA), V8 juice agar (V8), malt extract agar (MEA) and Czapek Dox agar (CDA). The optimum temperature for growth on PDA was in the range 20–25°C, with little or no growth occurring below 5°C or above 30°C. Hyphal extension occurred over a pH range between 2.6–8.6, with optimum values occurring at pH 5.5. In general, decreases in osmotic and matric potential caused a reduction in growth. Hyphal extension on media adjusted osmotically as NaCl ceased between −9.9 and −10.5 MPa. Isolates were more tolerant of osmotic than matric potential, with no growth occurring at −6.5 MPa on media adjusted with polyethylene glycol.
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    URL: http://dx.doi.org/10.1023/A:1008776611306
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    The effect of temperature on development and fecundityof Scymnus levaillanti (2000)
    Springer
    BioControl 45 (2000), S. 453-462 
    Details
    ISSN: 1573-8248
    Keywords: development ; fecundity ; functional response ; reproductive numerical response ; temperature ; Coccinellidae ; Aphis gossypii ; Scymnus levaillanti
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Development and fecundity of Scymnus levaillanti(Mulsant) were recorded at fiveconstant temperatures ranging from 15 to 35 ± 1 °C in 5 °C increments, 60 ± 5% RHand 16 h of artificial light (5000 Lux). Developmentaltime (egg to adult) of S. levaillantisignificantly decreased with increasing temperatures,ranging from 63.9 days at 15 °C to 11.1 days at35 °C. Development from egg to adult required305.2 DD above a developmental threshold estimated as11.7 °C. Oviposition periods lasted 86.5, 76.1,47.2, and 31.5 days at 20, 25, 30 and 35 °C,respectively. No eggs were deposited at 15 °C.Higher temperatures resulted in shorter generationtimes (TO) and in decreased net reproductiverates (RO) of the coccinellid. S.levaillanti kept at 30 °C produced 0.151females/female/day, the highest per capita rate ofpopulation growth (rm). The `functional response'of larvae and adults of S. levaillanti matcheswell that described by Holling (1959) as Type 2.Daily number of eggs deposited by females increased toa plateau with increasing prey density. Resultsobtained here provide information about the biology ofS. levaillanti, and its feeding capacityindicates that it may act as an important control agent.
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    URL: http://dx.doi.org/10.1023/A:1026505329762
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  • 20
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    Susceptibility of the legume flower thrips to Metarhizium anisopliae on different varieties of cowpea (2000)
    Springer
    BioControl 45 (2000), S. 79-95 
    Details
    ISSN: 1573-8248
    Keywords: anti-fungal substances ; control ; host plant resistance ; Megalurothrips sjostedti ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The susceptibility of Megalurothrips sjostedtito Metarhizium anisopliae when reared on susceptible, tolerant, and moderately resistant varieties of cowpea at different constant temperatures was evaluated in the laboratory. Insects were exposed either to direct spray of the conidia or to fungus-treated floral tissues. Mortality was significantly higher on the moderately resistant variety at all temperatures compared to the susceptible and tolerant varieties. Correspondingly, lethal time and lethal concentration values were significantly shorter and lower, respectively, on the moderately resistant variety compared to the other varieties, thus indicating that the two control methods are compatible as part of an integrated pest management strategy. Thrips raised on the tolerant variety incurred an exceptionally low level of mortality when the inoculum was sprayed directly on the insects or when the insects were exposed tofungus-treated floral tissues. Observations on the effects of airborne volatiles and crude extracts of this variety revealed an inhibitory effect on fungal germination, colony forming units and growth. This suggests the existence of anti-fungal substances in the tolerant variety.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009927302916
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  • 21
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    Storage and formulation of the entomopathogenicnematodes Heterorhabditis indica and H. bacteriophora (2000)
    Springer
    BioControl 45 (2000), S. 483-500 
    Details
    ISSN: 1573-8248
    Keywords: adjuvants ; attapulgite ; bentonite ; infectivity ; osmolarity ; pH ; survival ; temperature ; Heterorhabditis bacteriophora ; Heterorhabditis indica
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Successful control of insect pests through theapplication of entomopathogenic nematode dauerjuveniles of H. bacteriophora and H.indica can only be achieved when the nematodematerial reaches the end user in good condition.Storage and formulation techniques must provideoptimum conditions to guarantee a maximum survival andinfectivity of the nematodes. Nematode survival wastested at temperatures ranging between 5–25 °C.A maximum survival of H. indica was achieved at15 °C and the highest mortality at 5 °C.H. bacteriophora survived best at 7.5 °Cand least at 25 °C. An increase of the saltconcentration had positive effects on dauer juvenilesurvival in aqueous suspensions. Low pH between 6 and4 reduced the bacterial growth and prolonged survivalof stored dauer juveniles. Of the organic acidsascorbic, benzoic, citric and sorbic acid, onlyascorbic acid had a positive effect on H. indicasurvival. Extracts of the dried spice plants cinnamon,cloves, rosemary and oregano were tested. Enhancementof H. indica survival was recorded for cinnamonand cloves. Survival and infectivity of nematodesstored in attapulgite and bentonite clays and spongewere recorded over several weeks at different storagetemperatures. Infectivity was not influenced by thedifferent formulation materials. When stored insponge at 25 °C nematodes survived less than 1week and the formulation in clay could only prolongthis period for another week. At 5 °C thesurvival of H. bacteriophora in sponge wassuperior to that in clay, whereas H. indicasurvived less well in sponge than in clay at15 °C. Storage in aerated water at 5 °Cfor H. bacteriophora and at 15 °C for H. indica resulted in the lowest mortality. Forstorage at controlled conditions (temperature, pH andosmolarity), aerated water is superior to all othermethods tested and the addition of preservatives willincrease survival.
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    URL: http://dx.doi.org/10.1023/A:1026528727365
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    Temperature Effects on Soil Mineralization of Polylactic Acid Plastic in Laboratory Respirometers (1999)
    Springer
    Journal of polymers and the environment 7 (1999), S. 101-108 
    Details
    ISSN: 1572-8900
    Keywords: Polylactic acid ; temperature ; respirometers ; soil degradation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract A respirometric system was used to analyze the biodegradation of high molecular weight (120,000 to 200,000 g mol−1) polylactic acid (PLA) plastic films in soil under laboratory conditions. The respirometric system consisted of air-conditioning pretraps, a soil reactor, and a carbon dioxide (CO2) posttrap. A 200-g homogeneous soil mixture of all-purpose potting soil : manure soil : sand [1 : 1 : 1 (w/w)] and 1.5 g of PLA plastic films in 1 × 1-cm2 squares was added to each bottle. The respirometers were placed in a 28, 40, or 55°C water bath for 182 days. Treatments (three replicates) included native corn starch (positive control), polyethylene (Glad Cling Wrap; negative control), and three PLA films: Ca-I (Cargill Dow Polymers LLC, monolayer), GII (Cargill Dow Polymers LLC, Generation II), and Ch-I (Chronopol; monolayer). The degree of polymer mineralization was indicated by the cumulative CO2 liberated from each respirometer. The initial average mineralization rate and total percentage mineralized of the PLA plastic films at 28, 40, and 55°C was 24.3, 41.5, and 76.9 mg/day with a 27, 45, and 70% carbon loss, respectively. No decrease in soil pH was observed after 182 days of mineralization. Hence, increase in soil temperature drastically enhanced the biodegradation of PLA plastic films in soil under laboratory conditions (P 〈 0.0001).
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    URL: http://dx.doi.org/10.1023/A:1021812418325
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    Effects of Temperature and Relative Humidity on Polylactic Acid Plastic Degradation (1999)
    Springer
    Journal of polymers and the environment 7 (1999), S. 83-92 
    Details
    ISSN: 1572-8900
    Keywords: Polylactic acid ; temperature ; relative humidity ; degradation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Three high molecular weight (120,000 to 200,000 g mol−1) polylactic acid (PLA) plastic films from Chronopol (Ch-I) and Cargill Dow Polymers (GII and Ca-I) were analyzed for their degradation under various temperature and relative humidity (RH) conditions. Two sets of plastic films, each containing 11 samples, were randomly hung in a temperature/humidity-controlled chamber by means of plastic-coated paper clips. The tested conditions were 28, 40, and 55°C at 50 and 100% RH, respectively, and 55°C at 10% RH. The three tested PLA films started to lose their tensile properties when their weight-average molecular weight (M w) was in the range of 50,000 to 75,000 g mol−1. The average degradation rate of Ch-I, GII, and Ca-I was 28,931, 27,361, and 63,025 M w/week, respectively. Hence, GII had a faster degradation rate than Ch-I and Ca-I under all tested conditions. The degradation rate of PLA plastics was enhanced by the increase in temperature and relative humidity. This trend was observed in all three PLA plastics (Ca-I, GII, and Ch-I). Of the three tested films, Ch-I was the first to lose its mechanical properties, whereas Ca-I demonstrated the slowest loss, with mechanical properties under all tested conditions.
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    URL: http://dx.doi.org/10.1023/A:1021808317416
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    Algae of Lake Bai-Khol (Tuva, Russia) (1999)
    Springer
    International journal of salt lake research 8 (1999), S. 171-176 
    Details
    ISSN: 1573-8590
    Keywords: algae ; Lake Bai-Khol ; salinity ; Uvs-Nuur Basin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract The algal flora of Lake Bai-Khol, located in the endorheic Uvs-Nuur Basin, Russia, has been studied from collections made in August 1997. 79 taxa belonging to diatoms, blue-green and green algae were present.
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    URL: http://dx.doi.org/10.1023/A:1009019616569
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    A spatio-chemical survey of hydrogeothermal springs in Lake Elementaita, Kenya (1999)
    Springer
    International journal of salt lake research 8 (1999), S. 127-138 
    Details
    ISSN: 1573-8590
    Keywords: Lake Elementaita ; Lake Nakuru ; origin ; salinity ; thermal springs ; water chemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract The hydrochemistry of three areas of geothermal activity in the Lake Elementaita basin were surveyed. The results indicated warm temperatures between 30--40°C, high alkalinity (1,200 mg CaCO3/l) and specific conductance (4,300--8,100 µS/cm). pH was above 9 with a high concentration of carbonates, chlorides and sulphates. Apart from playing a significant role in the lake chemistry, lacustrine springs provide a significant source of water supply, particularly during the dry season. However, there is a serious lack of scientific information on the hydrogeology and hydrochemistry of the thermal springs.
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    URL: http://dx.doi.org/10.1023/A:1009023717477
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    Comparisons between the reproductive biology of black breamAcanthopagrus butcheri (Teleostei: Sparidae) in four estuaries with widely differing characteristics (1999)
    Springer
    International journal of salt lake research 8 (1999), S. 179-210 
    Details
    ISSN: 1573-8590
    Keywords: black bream ; estuaries ; fecundity ; fishery management ; length and age at maturity ; salinity ; spawning periods and locations ; water temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract The reproductive biology ofAcanthopagrus butcheri has been studied in the permanently open Swan River and intermittently open Moore River estuaries on the lower west coast of Australia (31–32°S) and in the permanently open Nornalup Walpole and normally closed Wellstead estuaries on the southern coast of Western Australia (34–35°S). Trends exhibited by gonadosomatic indices, gonadal maturity stages and the sizes and developmental stages of the oocytes demonstrate thatA. butcheri typically spawns in spring and early summer. However, spawning occurred in salinities ranging from as low as 3.5–8 gL−1 in the Moore River Estuary to as high as 41–45 g L−1 in the Wellstead Estuary. Furthermore, water temperatures during spawning were greater in the two northern estuaries (19.7–28.5°C) than in the two southern and cooler estuaries (17.5–23.4°C). Histological studies strongly indicate thatA. butcheri spawn more than once in a breeding season and demonstrate that the development of its oocytes exhibits group synchronysensu de Vlaming (1983). The ages and total lengths at which, on average, female and maleA. butcheri both first attain maturity in the Swan River Estuary were ca 2 years and ca 215 mm. However, the age at which individual fish in that system reach maturity was influenced by body size. This suggests that the attainment of first maturity at an older age but smaller length in the Moore River and Nornalup Walpole estuaries than is the case in the Swan River Estuary is a consequence of the slower growth rates ofA. butcheri in those estuaries. The combination of the young age (ca 2 years) but small length (ca 145 mm) at which maturity is first attained in the Wellstead Estuary could have resulted from selection pressures brought about by high mortality rates and/or heavy fishing pressure in this estuary. The mean fecundity ofA. butcheri, based on the combined number of yolk vesicle and yolk granule oocytes found in ovaries just prior to the onset of spawning, was 1580×103. The significance of the sizes at first maturity, minimum legal length for capture, mesh selectivity data and closure of certain regions of estuaries to fishing for the management of the recreational and commercial fishery forA. butcheri is discussed.
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    URL: http://dx.doi.org/10.1007/BF02449931
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    Salinity of surface waters in the Aral Sea region (1999)
    Springer
    International journal of salt lake research 8 (1999), S. 293-306 
    Details
    ISSN: 1573-8590
    Keywords: Aral Sea ; salinity ; salinization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract An overview of recent changes insalinity in the surface waters of the Aral sea basinis given. Total dissolved salts (salinity) in mostwaters are higher than admissible values fordrinking water, and ionic composition has changed withtime. Salinity of the `Big Sea' of the Aral was 48g L−1 in 1998, but has decreased to below 21g L−1 in the `Small Sea' due to the building ofa new dam between the two parts of the Aral Sea.
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    Effects of Temperature on Growth and Efficiency of Yolk Utilisation in Eggs and Pre-feeding Larval Stages of Atlantic Salmon (1999)
    Springer
    Aquaculture international 7 (1999), S. 81-87 
    Details
    ISSN: 1573-143X
    Keywords: alevin ; Atlantic salmon (Salmo salar) ; development ; egg ; temperature ; thermal tolerance ; yolk
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Three embryonic stages of Atlantic salmon (Salmo salar L.) were subjected to eight constant incubation temperatures (4, 7, 10, 12, 14, 16, 19 and 22 °C) exceeding the range usually experienced in natural conditions. A change in thermal tolerance during the embryonic and larval development was registered: pre-hatching stages showed an upper thermal limit at about 16 °C, while hatched larvae survived until 22 °C. Temperature significantly affects developmental rate, resulting in a faster development and, consequently, lower yolk weight percentage at higher temperatures. We found positive relationships between incubation temperature and body size (length and weight) in the less developed stages, in which some yolk remained, but size decreased at increasing temperatures when yolk was completely exhausted.
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    URL: http://dx.doi.org/10.1023/A:1009214804949
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    Growth and Chemical Composition of Spirulina Maxima and Spirulina Platensis Biomass at Different Temperatures (1999)
    Springer
    Aquaculture international 7 (1999), S. 261-275 
    Details
    ISSN: 1573-143X
    Keywords: cyanobacteria ; microalgae ; Spirulina ; Spirulina composition ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The influence of temperature on growth and biomass composition of two species of Spirulina, S. maxima and S. platensis used for food was studied. A 4L fermenter with temperature and agitation control was used to cultivate both species. Under continuous light, maximum cell production of 2.4 g l−1 was verified for both cultures studied at temperatures above 25 °C: S. maxima (30 °C and 35 °C) and S. platensis (25 °C and 30 °C). An accentuated lag phase was observed for all cultures at lower temperatures (15–20 °C), and a maximum biomass production of 1.5 g l−1 was achieved. It was also observed that an increase of temperature caused a marked decrease in protein content, while carbohydrate synthesis was stimulated. The concentration of γ-linolenic acid varied from 11–16% for S. maxima and from 12–14% for S. platensis, at the optimum growth temperatures. Greater culture volumes were also studied in order to compare the performance of glass and plastic containers. At optimum growth temperature, S. maxima produced the same cell growth and similar final biomass composition.
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    A spatio-chemical survey of hydrogeothermal springs in Lake Elementaita, Kenya (1999)
    Springer
    International journal of salt lake research 8 (1999), S. 127-138 
    Details
    ISSN: 1573-8590
    Keywords: Lake Elementaita ; Lake Nakuru ; origin ; salinity ; thermal springs ; water chemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract The hydrochemistry of three areas of geothermal activity in the Lake Elementaita basin were surveyed. The results indicated warm temperatures between 30–40°C, high alkalinity (1,200 mg CaCO3/l) and specific conductance (4,300–8,100 μS/cm). pH was above 9 with a high concentration of carbonates, chlorides and sulphates. Apart from playing a significant role in the lake chemistry, lacustrine springs provide a significant source of water supply, particularly during the dry season. However, there is a serious lack of scientific information on the hydrogeology and hydrochemistry of the thermal springs.
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    URL: http://dx.doi.org/10.1007/BF02442126
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    Hydrological exchange and subsurface water chemistry in streams varying in salinity in south-western Australia (1999)
    Springer
    International journal of salt lake research 8 (1999), S. 361-382 
    Details
    ISSN: 1573-8590
    Keywords: Aral Sea ; salinity ; salinization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract Many streams in Western Australia are naturally saline. In others, especiallyin the south-western corner, land-clearance and other human activities inthe catchment have accelerated rates of salinisation of surface andgroundwater. Trends in surface water salinity are well-documented but theextent of penetration of saline stream water into the sediments has beenlittle studied. As many of these streams have porous sandy beds and theirflows may derive from groundwater, hydrologic exchange patterns betweensurface water and subsurface hyporheic water were hypothesised togovern the water chemistry of such rivers. We predicted high rates ofhydraulic conductivity, leading to a close relationship between surface andsubsurface (to a depth of 50 cm) salinity, and to a lesser extent, pH anddissolved oxygen. Where surface and hyporheic water differed in salinity,other chemical differences were hypothesised to be similarly marked,perhaps resulting from disjunct shallow subsurface aquifers. Triplicatewells were sampled from upwelling and downwelling zones of thirteenstreams ranging in salinity from ca. 0.2 to 18 g L−1. Despite theseemingly-porous sandy beds at many sites, subsurface water chemistryonly 20–40 cm below the bed sometimes differed markedly from surfacewater. For example, hyporheic water was only one-fifth the salinity ofsurface water at some saline sites (e.g., the Tone River) or 20 per cent moresaline in streams with fresh surface water (e.g., the Weld River). At somesites of intermediate salinity (e.g., the Warren River), subsurface water wasup to three times fresher than surface or downwelling water. Percentagesaturation of dissolved oxygen in the hyporheic water was consistently low(〈 40%) whereas pH was more acidic than surface water, presumably dueto microbial activity. Vertical hydraulic conductivity may be limited bylayers of fine sediments and clays, implying that the meso-scale (1–100 cm)hydrological dynamics within the hyporheic zones of these rivers are morecomplex than their sandy beds would indicate. Assumptions of ecosystemdynamics in saline streams must be tempered by an understanding ofhyporheic salinities as subsurface fresher water may support microbial andfaunal assemblages excluded from the surface benthos by high salinity. Insaline streams, as in fresh ones, the hyporheic zone is an importantcomponent of the stream ecosystem and equally prone to disruption byhuman activities.
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    The salinity of hypersaline brines: Concepts and misconceptions (1999)
    Springer
    International journal of salt lake research 8 (1999), S. 55-70 
    Details
    ISSN: 1573-8590
    Keywords: Dead Sea ; equation of state ; pycnometry ; salinity ; saturation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract Some widespread misconceptions about salinity are pointed out, explained and commented on. Definitions, units, and methods of salinity determination recommended for brines of moderate salinities may become unsuitable for highly saline brines. Various salinity units are examined and commented on, and density at a precisely monitored temperature is chosen as the preferable “substitute parameter” for salinity determination of hypersaline brines. It is shown that ambient air density during pycnometric measurements must be known as accurately as required of the brine's density, and that its value must be added to the direct pycnometric measurement. Variations of atmospheric pressure at the time of pycnometry must be taken into account if greater than 15 mB. For a salinity accuracy of ±0.02 per mille, as required for some physical and chemical studies, the temperature of the sample during salinity measurement must be monitored with an accuracy of at least 0.04°C. A definite curve in the ρ-S plane, corresponding to the conversion of salinity to density at a fixed temperature, andvice-versa, does not exist if the brine is saturated in one of its salts. Non-linearity in the equation of state is shown to affect the surface level drop due to evaporation; the effect is negligible at low salinities, but a 10 per cent correction is already required at the salinity found in the northern Red Sea (41 per mille). Reliable reference points for the conversion of absolute salinity to density of highly saline brines are not known, at present, as accurately as desirable; pending the accurate determination of such reference points, a substantial dilution of hypersaline brines (for the purpose of adapting them to conductivity measurements) would multiply the error range by more than a hundred fold. On the other hand, a minute dilution of hypersaline brine samples to prevent salt crystal formation is possible and would not bring about any major increase of the error range in their density (salinity) determination.
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    URL: http://dx.doi.org/10.1007/BF02442137
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    Algae of Lake Bai-Khol (Tuva, Russia) (1999)
    Springer
    International journal of salt lake research 8 (1999), S. 171-176 
    Details
    ISSN: 1573-8590
    Keywords: algae ; Lake Bai-Khol ; salinity ; Uvs-Nuur Basin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract The algal flora of Lake Bai-Khol, located in the endorheic Uvs-Nuur Basin, Russia, has been studied from collections made in August 1997. 79 taxa belonging to diatoms, blue-green and green algae were present.
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    URL: http://dx.doi.org/10.1007/BF02442129
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    The salinity of hypersaline brines: Concepts and misconceptions (1999)
    Springer
    International journal of salt lake research 8 (1999), S. 55-70 
    Details
    ISSN: 1573-8590
    Keywords: Dead Sea ; equation of state ; pycnometry ; salinity ; saturation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract Some widespread misconceptions about salinity are pointed out, explained and commented on. Definitions, units, and methods of salinity determination recommended for brines of moderate salinities may become unsuitable for highly saline brines. Various salinity units are examined and commented on, and density at a precisely monitored temperature is chosen as the preferable “substitute parameter” for salinity determination of hypersaline brines. It is shown that ambient air density during pycnometric measurements must be known as accurately as required of the brine's density, and that its value must be added to the direct pycnometric measurement. Variations of atmospheric pressure at the time of pycnometry must be taken into account if greater than 15 mB. For a salinity accuracy of ±0.02 per mille, as required for some physical and chemical studies, the temperature of the sample during salinity measurement must be monitored with an accuracy of at least 0.04°C. A definite curve in the ρ-S plane, corresponding to the conversion of salinity to density at a fixed temperature, and vice-versa, does not exist if the brine is saturated in one of its salts. Non-linearity in the equation of state is shown to affect the surface level drop due to evaporation; the effect is negligible at low salinities, but a 10 per cent correction is already required at the salinity found in the northern Red Sea (41 per mille). Reliable reference points for the conversion of absolute salinity to density of highly saline brines are not known, at present, as accurately as desirable; pending the accurate determination of such reference points, a substantial dilution of hypersaline brines (for the purpose of adapting them to conductivity measurements) would multiply the error range by more than a hundred fold. On the other hand, a minute dilution of hypersaline brine samples to prevent salt crystal formation is possible and would not bring about any major increase of the error range in their density (salinity) determination.
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    URL: http://dx.doi.org/10.1023/A:1009059827435
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    Comparisons between the reproductive biology of black bream Acanthopagrus butcheri (Teleostei: Sparidae) in four estuaries with widely differing characteristics (1999)
    Springer
    International journal of salt lake research 8 (1999), S. 179-210 
    Details
    ISSN: 1573-8590
    Keywords: black bream ; estuaries ; fecundity ; fishery management ; length and age at maturity ; salinity ; spawning periods and locations ; water temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract The reproductive biology of Acanthopagrus butcheri has been studied in the permanently open Swan River and intermittently open Moore River estuaries on the lower west coast of Australia (31--32 °S) and in the permanently open Nornalup Walpole and normally closed Wellstead estuaries on the southern coast of Western Australia (34--35 °S). Trends exhibited by gonadosomatic indices, gonadal maturity stages and the sizes and developmental stages of the oocytes demonstrate that A. butcher typically spawns in spring and early summer. However, spawning occurred in salinities ranging from as low as 3.5-8 g L−1 in the Moore River Estuary to as high as 41-45 g L−1 in the Wellstead Estuary. Furthermore, water temperatures during spawning were greater in the two northern estuaries (19.7--28.5 °C) than in the two southern and cooler estuaries (17.5--23.4 °C). Histological studies strongly indicate that A. butcheri spawn more than once in a breeding season and demonstrate that the development of its oocytes exhibits group synchrony sensu de Vlaming (1983). The ages and total lengths at which, on average, female and male A. butcheri both first attain maturity in the Swan River Estuary were ca 2 years and ca 215 mm. However, the age at which individual fish in that system reach maturity was influenced by body size. This suggests that the attainment of first maturity at an older age but smaller length in the Moore River and Nornalup Walpole estuaries than is the case in the Swan River Estuary is a consequence of the slower growth rates of A. butcheri in those estuaries. The combination of the young age (ca 2 years) but small length (ca 145 mm) at which maturity is first attained in the Wellstead Estuary could have resulted from selection pressures brought about by high mortality rates and/or heavy fishing pressure in this estuary. The mean fecundity of A. butcheri, based on the combined number of yolk vesicle and yolk granule oocytes found in ovaries just prior to the onset of spawning, was 1580 × 103. The significance of the sizes at first maturity, minimum legal length for capture, mesh selectivity data and closure of certain regions of estuaries to fishing for the management of the recreational and commercial fishery for A. butcheri is discussed.
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    Salinity of surface waters in the Aral sea region (1999)
    Springer
    International journal of salt lake research 8 (1999), S. 293-306 
    Details
    ISSN: 1573-8590
    Keywords: Aral Sea ; salinity ; salinization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract An overview of recent changes in salinity in the surface waters of the Aral sea basin is given. Total dissolved salts (salinity) in most waters are higher than admissible values for drinking water, and ionic composition has changed with time. Salinity of the ‘Big Sea’ of the Aral was 48 g L−1 in 1998, but has decreased to below 21 g L−1 in the ‘Small Sea’ due to the building of a new dam between the two parts of the Aral Sea.
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    URL: http://dx.doi.org/10.1007/BF02442116
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    Effects of Temperature on Infection in Capsicum sp. and Nicotiana benthamiana by Impatiens Necrotic Spot Tospovirus (1999)
    Springer
    European journal of plant pathology 105 (1999), S. 509-512 
    Details
    ISSN: 1573-8469
    Keywords: tospovirus ; resistance ; Capsicum sp. ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Infection by two isolates of impatiens necrotic spot tospovirus (INSV) under temperature regimes of 25/18°C (day/night) or 33°C (continuous) was studied in Capsicum annuum (systemically susceptible to tomato spotted wilt tospovirus, TSWV), C. chinense PI 152225 and PI 159236 (reacting hypersensitively to TSWV) and Nicotiana benthamiana (systemically susceptible to both tospoviruses). At 25/18°C infection was systemic in all hosts tested. At 33°C infection in N. benthamiana was systemic whereas in C. annuum and C. chinense it was restricted to the inoculated leaves. The result differed from that reported for TSWV, where high temperature made plants more susceptible, or caused no difference. Exchanging temperature regimes 6 h to 4 days after inoculation did not affect the final results one month later, with plants being only locally infected at 33°C continuous regime, or systemically infected at 25/18°C alternate regime. The two INSV isolates were biologically and serologically stable for 5 passages in N. benthamiana held continuously at 33°C.
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    Floral initiation in field-grown forage peas is delayed to a greater extent by short photoperiods, than in other types of European varieties (1999)
    Springer
    Euphytica 109 (1999), S. 201-211 
    Details
    ISSN: 1573-5060
    Keywords: Pisum sativum L. ; frost resistance ; floral initiation ; photoperiod ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Frost is one of the main climatic stresses which has to be overcome by a winter pea crop. Some forage lines show a delayed floral initiation, which helps them to escape the main winter freezing periods, as a higher susceptibility to frost is observed after floral initiation commences. Frost tolerant forage peas have been used in all winter pea breeding programs in France and our main purpose was to evaluate to what extent those lines and the current winter varieties are variable for the date of floral initiation in field conditions. A field experiment was carried out during two years at the INRA experimental station of Mons (northern France). Different genotypes (9 in 1995–1996 and 12 in 1996–1997) were sown at approximately monthly intervals between September and June to provide a range of photothermal conditions. The date of floral initiation was determined by destructive sampling. We observed variability for the date of floral initiation among the different genotypes and sowing dates. Our data particularly highlighted the different reactions to photoperiod. Three varieties had no detectable reaction. Six varieties exhibited a quantitative response, with varied intensities. Lastly, the three forage varieties showed a qualitative, high response to photoperiod, which indicated the presence of the Hr allele, already described in Pisum.
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    Effect of salinity on the association between root symbionts and Acacia cyanophylla Lind.: growth and nutrition (1999)
    Springer
    Plant and soil 216 (1999), S. 93-101 
    Details
    ISSN: 1573-5036
    Keywords: Acacia cyanophylla ; endomycorrhizae ; growth ; nutrition ; Rhizobia ; salinity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The behaviour of Acacia cyanophylla Lind. plants submitted to salinity stress was followed in the greenhouse. The plants were associated with indigenous symbiotic microorganisms isolated from the coastal dunes of the Souss-Massa region. A two months period of salinity had a large negative impact on plant growth and acquisition of macro nutrients. However, the study underlined the role of the microbial inoculum for the plant in the achievement of salt tolerance. An isolate of Bradyrhizobium sp., RCM6 (R1), originating from the Massa dunes, was highly efficient in improving growth and nutrition of the A. cyanophylla. Double inoculation with the rhizobia and an endomycorrhizal complex, isolated from the Lamzar dunes had a clear additional positive effect, i.e. the fungi further increased the tolerance of the A. cyanophylla plants to salinity.
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    Ammonium and nitrate uptake by Eucalyptus nitens: effects of pH and temperature (1999)
    Springer
    Plant and soil 214 (1999), S. 133-140 
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    ISSN: 1573-5036
    Keywords: ammonium ; eucalyptus ; nitrate ; pH ; root uptake ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Ammonium and nitrate uptake by roots of Eucalyptus nitens was characterised with respect to pH and temperature. Uptake of ammonium and nitrate was measured as depletion from solutions by roots of intact 11 week old solution-cultured seedlings. Uptake rates of ammonium were consistently higher than those of nitrate in all experiments. Uptake rates for ammonium were 200% higher at pH 4 than at pH 6, but for nitrate were unchanged. Uptake rates of ammonium and nitrate were both reduced to a similar extent (70%) with a decrease in temperature from 20 °C to 10 °C. For ammonium uptake, there was rapid (〈24 hr) adaptation to a reduction in root temperature. The apparent preference shown here for ammonium over nitrate could be indicative of E. nitens growing in cold, acidic forest soils where ammonium is commonly more available than nitrate. These results suggest that N uptake rates of E. nitens may be maximised under a wide variety of conditions if N is supplied predominantly in the ammonium form.
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    Feed Intake and Growth of Juvenile Silver Trevally at the Southern Limit of Their Distribution (1999)
    Springer
    Aquaculture international 7 (1999), S. 357-360 
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    ISSN: 1573-143X
    Keywords: feed intake ; growth ; silver trevally (Pseudocaranx dentex) ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009296531292
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    Effect of source and nest size of N fertilizers and temperature on nitrification in a coarse textured, alkaline soil (1999)
    Springer
    Nutrient cycling in agroecosystems 54 (1999), S. 199-207 
    Details
    ISSN: 1573-0867
    Keywords: ammonium chloride ; ammonium sulphate ; nest placement ; nitrification ; temperature ; urea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Nitrification occurring in an alkaline sandy loam soil fertilized with urea, ammonium sulphate (AS) and ammonium chloride (AC) was studied in the laboratory at 20°C and 40°C for 30 days. Nitrogen fertilizers were applied as nest of sizes 0.2, 0.5, 1.0 and 2.0 g. Unfertilized control and soil mixed with 50 mg N kg-1 were also included as treatments. Nitrification in all the fertilizer treatments decreased markedly with increasing nest size. At 20°C, differences among the three N sources were not significant at 5 days after incubation but marked differences appeared thereafter. All the N was nitrified by 30 days in case of fertilizers mixed into the soil. In nest placement, nitrification ranged from 30.1 to 75.5%, 28.3 to 74.6% and 35.3 to 88.7% for urea, AC and AS, respectively. When equal amounts of fertilizers were placed in a nest, nitrification occurred at a slower rate with urea than with AC and AS. Rates of nitrification were significantly higher at 40°C than at 20°C. At 20 days, nitrification from different nest sizes ranged from 8.4 to 64.9% and from 24.9 to 87.0% at 20°C and 40°C, respectively. The difference in nitrification at two temperatures were more pronounced at higher nest sizes than at smaller nest sizes. While nitrification with the three N sources decreased linearly with increase in N concentration (nest size) in soil at 40°C, it showed a quadratic relationship at 20°C. At equal N concentration, the highest rate of nitrification occurred with urea and the lowest with AC. At the same rate of applied N (50–2000 mg kg-1), AC and AS increased electrical conductivity of soil by 1.3–9 times that of urea. Apparent mineral N recovery of applied N decreased with the increase in nest size.
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    Realizing the Potential of Integrated Irrigation and Drainage Water Management for Meeting Crop Water Requirements in Semi-Arid and Arid Areas (1999)
    Springer
    Irrigation and drainage systems 13 (1999), S. 321-347 
    Details
    ISSN: 1573-0654
    Keywords: cotton ; drainage ; irrigation ; salinity ; shallow groundwater ; tomato
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract In situ use of ground water by plants is one optionbeing considered to reduce discharge of subsurfacedrainage water from irrigated agriculture. Laboratory, lysimeter, and field studies havedemonstrated that crops can use significant quantitiesof water from shallow ground water. However, moststudies lack the data needed to include the crop wateruse into an integrated irrigation and drainage watermanagement system. This paper describes previousstudies which demonstrated the potential use of groundwater to support plant growth and the associatedlimitations. Included are results from three fieldstudies which demonstrated some of the managementtechniques needed to develop an integrated system. The field studies demonstrated that approximately 40to 45% of the water requirement for cotton can bederived from shallow saline ground water. Thatregulation of the outflow will result in increasinguse. Implementation of integrated management ofirrigation and subsurface drainage systems is a viableand sustainable alternative in the management ofsubsurface drainage water from arid and semi-aridareas only if soil salinity can be managed and if thesystem is profitable.
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    Agroforestry for water management in the cropping zone of southern Australia (1999)
    Springer
    Agroforestry systems 45 (1999), S. 277-302 
    Details
    ISSN: 1572-9680
    Keywords: alley cropping ; deep drainage ; revegetation ; salinity ; tree crop interactions ; tree water use
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Agroforestry has been advocated as a means of managing excess water that has accumulated in the agricultural landscape of southern Australia since clearing of native vegetation. This article examines the feasibility and profitability of agroforestry systems designed to manage rising, saline watertables. A framework for Australian conditions is described that considers the interactions between trees, crops and their below ground environment and how they influence water use, crop yield and profitability. Data is presented from a study of a commercial scale agroforestry system under ideal conditions where trees have access to a shallow fresh water table. The discussion is then broadened to encompass soil, relief and ground water conditions more typical of the southern Australian cropping zone. The relative merits of segregating, integrating and rotating trees with crops are then examined. It is concluded that, in most cases, trees would need to be widely dispersed over a significant proportion of the landscape to manage deep drainage and salinity. Agroforestry is therefore only likely to be an effective solution to water management where trees can compete directly on commercial terms with conventional agriculture. Given the generally low rates of biomass accumulation in semi-arid woody species, this presents a significant challenge for agroforestry in the cropping zone of southern Australia.
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    Applicability of Fatigue Life Prediction Method to Polymer Composites (1999)
    Springer
    Mechanics of time-dependent materials 3 (1999), S. 141-157 
    Details
    ISSN: 1573-2738
    Keywords: CFRP ; fatigue ; frequency ; stress ratio ; temperature ; viscoelasticity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract A prediction method of fatigue strength under an arbitraryfrequency, temperature, and stress ratio is proposed for polymercomposites and its validity is confirmed for the flexural fatiguestrength of satin-woven CFRP laminates. This method is based upon fourhypotheses: (a) same failure process under constant strain-rate (CSR),creep, and fatigue loadings, (b) same time-temperature superpositionprinciple for all failure strengths, (c) linear cumulative damage lawfor nondecreasing stress process, and (d) linear dependence of fatiguestrength upon stress ratio. This method was applied to the flexuralfatigue strength of various unidirectional CFRPs, and the verificationand limitations of this method were discussed.
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    The influence of temperature, photoperiod and plant type on the predation rate of Macrolophus pygmaeus on Myzus persicae (1999)
    Springer
    BioControl 44 (1999), S. 281-289 
    Details
    ISSN: 1573-8248
    Keywords: Macrolophus pygmaeus ; photoperiod ; predation rate ; temperature ; predator
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The effect of temperature and photoperiod on the rate of predation of nymphs and adults of the predator Macrolophus pygmaeus was studied using Myzus persicae prey feeding on egg-plant and pepper plants. The experiments were conducted at three photoperiods (16L:8D, 12L:12D and 8L:16D), three temperatures (20, 25 and 30 °C), and at 65% r.h. The rate of predation increased with temperature. Predation rate was affected by photoperiod on pepper but not on egg-plant. Females and fifth instar nymphs were the most voracious stages followed by third and fourth instar nymphs and males. First and second instar nymphs consumed far fewer aphids. Predation rate was higher on leaves of pepper than egg-plant, especially at 30 °C. Variation in the efficacy of this predator is discussed.
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    Competitive ability of the antagonists Ulocladium atrum and Gliocladium roseum at temperatures favourable for Botrytis spp. development (1999)
    Springer
    BioControl 44 (1999), S. 329-346 
    Details
    ISSN: 1573-8248
    Keywords: biological control ; Botrytis aclada ; Botrytis cinerea ; cyclamen ; ecological adaptation ; hydrangea ; lily ; onion ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Ulocladium atrum and Gliocladium roseum are fungal antagonists capable of suppressing sporulation of Botrytis spp. on dead plant parts. The effect of temperature (3 to 36 °C) on antagonist conidial germination and mycelial growth was assessed on agar. In addition conidial germination of U. atrum was measured on dead lily leaves. The optimum temperature of both antagonists for both conidial germination and mycelial growth was between 27 and 30 °C. U. atrum was less affected by lower temperatures than G. roseum. At optimum temperature, 50% of conidia of U. atrum and G. roseum germinated within 2.6 and 10.0 hrs, respectively. At low sub-optimal temperatures (6 °C), 50% of conidia germinated within 18 and 96 hours, respectively. In bioassays on dead onion leaves, U. atrum suppressed sporulation of B. cinerea and B. aclada at all temperatures tested (6 to 24 °C) by more than 85%. On dead cyclamen leaves, G. roseum was more efficient than U. atrum at 21 and 24 °C but, in contrast to U. atrum, showed no antagonistic activity at temperatures below 21 °C. On dead hydrangea leaves, U. atrum significantly reduced sporulation of B. cinerea at temperatures as low as 3 and 1 °C. Under Dutch growing conditions, the mean air temperature during leaf wetness periods in onion and lily fields was 15 °C with temperatures only occasionally above 20 °C. In greenhouse crops of cyclamen, the mean temperature during high humidity periods was 17 °C. It is therefore concluded that U. atrum is better adapted than G. roseum to temperatures which occur in the field, in greenhouse crops such as cyclamen, or during cold storage of plant stocks.
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    Methodology for minimizing effects of temperature in monitoring with the acousto-ultrasonic technique (1999)
    Springer
    Experimental mechanics 39 (1999), S. 86-91 
    Details
    ISSN: 1741-2765
    Keywords: Acousto-ultrasonic ; damage monitoring ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The acousto-ultrasonic (AU) technique can be a useful methodology for monitoring structures or mechanical components during endurance tests, fatigue tests or, in general, during the life of the components. To obtain reliable information about the failure and fatigue cracks at their earliest initiation stages and to follow their evolution regardless of any disturbance effects, refined experimental procedures and signal processing are needed. In particular, the effects of temperature variation cannot be entirely suppressed and are difficult to evaluate. This means that the results of the AU technique are not immediately interpretable and usable for monitoring structures. This paper describes some procedures aimed at minimizing the effects of disturbance on AU signals caused by temperature variation, allowing use of AU for monitoring over extensive periods of time or when the component is subjected to heating.
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    URL: http://dx.doi.org/10.1007/BF02331110
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    Thermoelastic contact problem of two rotating bodies with frictional heat generation in annular region (1998)
    Springer
    Archive of applied mechanics 68 (1998), S. 128-136 
    Details
    ISSN: 1432-0681
    Keywords: Key words frictional heating ; temperature ; contact pressure ; punch indentation ; thermoelasticity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary An axisymmetric contact problem with frictional heating is considered in which a parabolic annular punch is pressed into a plane surface and rotates about its axis of symmetry at constant speed. The problem is formulated in terms of one governing equation with unknown pressure. This equation is solved numerically. The change of the geometry of the contact region and pressure has been investigated.
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    URL: http://dx.doi.org/10.1007/s004190050150
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    Towards a Predictive Design Methodology Based on the Physical Modelling of the Fracture of Fiber Composites (1998)
    Springer
    Applied composite materials 5 (1998), S. 69-94 
    Details
    ISSN: 1573-4897
    Keywords: modelling ; notch strength ; damage ; fatigue ; environment ; temperature ; prediction ; design
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract A predictive design methodology based on modelling the fracture stress (notched tensile strength) and post-fatigue residual strength of laminated fiber composites is presented. The approach is based explicitly on the development of models of the physical processes by which damage accumulates at a notch-tip and the application of these models to cross-ply laminates for a variety of material systems, including thermosetting and thermoplastic matrices containing carbon, glass and Kevlar fiber reinforcements. The effects of temperature and humidity on composite fracture can also be examined in the context of this modelling strategy. A pre-requisite of the model is that it has to be calibrated for each material system by performing tensile tests on notched and unnotched cross-ply laminate. From this initial calibration, which takes relatively little time, it is possible to apply the model to a prediction of the dependence of fracture stress on notch size; to an understanding of the effects of laminate stacking sequence (within the same cross-ply family) on fracture stress; and to provide insight into the effects of thermal or load cycling history on fatigue damage-growth and residual or fatigue strength. The advantages and deficiencies of this modelling strategy are assessed, as well as the applicability of such a physical modelling approach to the predictive design and failure of composite materials in general.
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    URL: http://dx.doi.org/10.1023/A:1008811721083
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    On the Spectral Decomposition of Geopotential and Temperature Fields in the Stratosphere (1998)
    Springer
    Studia geophysica et geodaetica 42 (1998), S. 147-158 
    Details
    ISSN: 1573-1626
    Keywords: stratosphere ; spectral decomposition ; geopotential ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Geosciences , Physics
    Notes: Abstract The spectral structure of stratospheric fields (temperature and geopotential) is analyzed in terms of spherical harmonics in an effort to study the long-term behaviour of large-scale circulation patterns, as well as their connections to some extra-terrestrial effects. The daily meteorological data from the Free University Berlin (FUB) cover more or less the period 1976–1996 and are available for stratospheric levels of 50, 30 and 10 hPa. The analysis of the annual cycle of spherical harmonics is introduced, and changes of the principal wave components are compared with the changes in different sets of solar, geomagnetic and global circulation indices. This paper also deals with interannual variability with special emphasis on quasibiennial oscillations (QBO) and El Nino and Southern Oscillations (ENSO). Although this is a rather preliminary study, the decomposition of the stratospheric field into complex spherical harmonics seems to be a powerful technique in investigating and qualifying the response of the global atmospheric system to the changes in solar and geomagnetic activity, and in qualifying the relationships between large-scale circulation patterns and various oscillations such as QBO or ENSO, Using this technique, reasonable strong connections were found between wave numbers and interannual factors, and these connections were tentatively interpreted in terms of statistics. A very high degree of correlation was found for the four-trough shape of the polar vortex.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1023305020573
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    Changes of Ozone Content at Middle Latitudes During Forbush Decreases in Cosmic Rays (1998)
    Springer
    Studia geophysica et geodaetica 42 (1998), S. 521-532 
    Details
    ISSN: 1573-1626
    Keywords: stratospere ; troposphere ; solar-terrestrial disturbances ; odd nitrogen ; temperature ; atmospheric dynamics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Geosciences , Physics
    Notes: Abstract The variations of total ozone at Alma-Ata (43°N, 76 °E) and ozone profiles obtained by balloon sounding at Tateno (36°N, 140°E), Wallops Island (38°N, 75°W) and Cagliari (39°N, 9°E) in the periods of Forbush decreases (FD) in galactic cosmic rays have been analysed. A decrease of total ozone was observed in the initial stage of the FD and an increase 10–11 days later. The average total deviations calculated using the superposed epoch method for 9 FD events are equal to 30 D. U. in the positive and to −18 D. U. in the negative phase. The changes of average ozone profiles, associated with 26 FD events, are more significant in the lower stratosphere and upper troposphere. The decrease of the partial ozone pressure at a height of 12–15 km is about 30 υmb. These vertical variations of ozone coincide with the average changes of the respective temperature profiles. A cooling, on the average, of 3°C was observed at 12–15 km, and a heating of 4°C below this level.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1023301322428
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    Numerical prognosis for salinity profiles of future lakes in the opencast mine Merseburg-Ost (1998)
    Springer
    International journal of salt lake research 7 (1998), S. 235-260 
    Details
    ISSN: 1573-8590
    Keywords: groundwater ; Merseburg-Ost ; mine ; meromixis ; numerical model ; monimolimnion ; opencast ; physical limnology ; salinity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract Salt-laden groundwater inflows have formed monimolimnia in developing lakes of the abandoned opencast lignite mine Merseburg-Ost, Central Germany. Water-levels are still rising. To predict the future status of the lakes, two numerical models were developed. One was designed to predict groundwater flows, the second included limnophysical processes. The models were run in parallel and data exchange between them was performed every 1 to 10 years of model time. A trial of a 100-years prognosis was done. The results of surface salinity, mixing depth, and salinity profile are given. A sensitivity analysis yielded indications for the accuracy of the prediction.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009097319823
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    Potential salinity limitations on nitrogen fixation in sediments from Mono Lake, California (1998)
    Springer
    International journal of salt lake research 7 (1998), S. 261-274 
    Details
    ISSN: 1573-8590
    Keywords: cyanobacteria ; lake management ; Mono Lake ; nitrogen fixation ; salinity ; saline lakes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract Mono Lake is a hypersaline alkaline lake in the high altitude Great Basin desert of eastern California. Algal productivity of the lake is nitrogen-limited, and a contributing source is derived from benthic nitrogen fixation. Lake level and salinity have fluctuated with natural climatic variations but have also been affected by the diversion of tributary streams. This research examines the influence of varied salinity and lake level on the potential for benthic nitrogen fixation in Mono Lake. A sediment-surface microbial mat community was exposed directly, and in acclimated cultures, to a range of Mono Lake salinities under anaerobic incubations and the activity of nitrogenase assayed by acetylene reduction. Activity was stimulated in light, but also occurred in darkness. Over an experimental salinity range from 50 to 150 g L−1 TDS, nitrogenase activity was reduced by 90 per cent, with the activity persisting at the highest salinity being attributable to dark fixation alone. Between a salinity of 50 g L−1, occurring in Mono Lake over 50 years ago, and 100 g L−1, nitrogenase activity was reduced by nearly half. Changes in the area of the littoral zone at varied lake levels also affect the total amount of potential benthic nitrogen fixation in the lake. An accounting of yearly inputs of nitrogen to Mono Lake suggests N2-fixation could contribute as much as 76–81 percent of the total. Inhibition of nitrogen fixation rates by increased salinity could limit the long-term nutrient supply and benthic primary productivity of this ecosystem.
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    URL: http://dx.doi.org/10.1007/BF02441878
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    Interactive effects of elevated carbon dioxide and growth temperature on photosynthesis in cotton leaves (1998)
    Springer
    Plant growth regulation 26 (1998), S. 33-40 
    Details
    ISSN: 1573-5087
    Keywords: carbohydrates ; elevated CO2 ; Gossypium hirsutum L. ; interaction ; photosynthesis ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Cotton (Gossypium hirsutum L., cv DPL 5415) plants were grown in naturally lit environment chambers at day/night temperature regimes of 26/18 (T-26/18), 31/23 (T-31/23) and 36/28 °C (T-36/28) and CO2 concentrations of 350 (C-350), 450 (C-450) and 700 μL L-1 (C-700). Net photosynthesis rates, stomatal conductance, transpiration, RuBP carboxylase activity and the foliar contents of starch and sucrose were measured during different growth stages. Net CO2 assimilation rates increased with increasing CO2 and temperature regimes. The enhancement of photosynthesis was from 24 μmol CO2 m-2 s-1 (with C-350 and T-26/18) to 41 μmol m-2 s-1 (with C-700 and T-36/28). Stomatal conductance decreased with increasing CO2 while it increased up to T-31/23 and then declined. The interactive effects of CO2 and temperature resulted in a 30% decrease in transpiration. Although the leaves grown in elevated CO2 had high starch and sucrose concentrations, their content decreased with increasing temperature. Increasing temperature from T-26/18 to 36/28 increased RuBP carboxylase activity in the order of 121, 172 and 190 μmol mg-1 chl h-1 at C-350, C-450 and C-700 respectively. Our data suggest that leaf photosynthesis in cotton benefited more from CO_2 enrichment at warm temperatures than at low growth temperature regimes.
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    URL: http://dx.doi.org/10.1023/A:1006035517185
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    The relationship between electrical conductivity and selected macroinvertebrate communities in four river systems of south-west Victoria, Australia (1998)
    Springer
    International journal of salt lake research 7 (1998), S. 153-170 
    Details
    ISSN: 1573-8590
    Keywords: confounding parameters ; nutrients ; salinity ; survey design
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract In order to relate macroinvertebrate fauna to electrical conductivity (EC), a survey of selected orders of macroinvertebrates was conducted in the Glenelg, Hopkins, Merri and Barwon River Catchments in south-west Victoria, Australia. The survey consisted of sampling 21 paired sites at confluences of streams. There was little difference between the in-stream habitat but there was a range of differences in EC between each of the paired sites. The dissimilarity of macroinvertebrate fauna between the paired sites was compared to the proportional difference in EC and other water quality variables (dissolved oxygen, water temperature, pH, NO2−N, NO3−N, PO4 and turbidity). This allowed the elimination of EC being confounded with geographical scale parameters and took into account other water quality parameters that may be confounded with EC. A positive relationship was found between the dissimilarity of the fauna at each of the two paired sites and the proportional difference in EC. No such relationship was found for any other measured water quality variable. The results of this survey show that macroinvertebrate community structure is associated with EC of the river systems investigated after eliminating large scale geographical patterns, in-stream habitat and the measured water quality parameters.
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    URL: http://dx.doi.org/10.1007/BF02441884
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    Potential salinity limitations on nitrogen fixation in sediments from Mono Lake, California (1998)
    Springer
    International journal of salt lake research 7 (1998), S. 261-274 
    Details
    ISSN: 1573-8590
    Keywords: cyanobacteria ; lake management ; Mono Lake〉/kwd〉 ; nitrogen fixation ; salinity ; saline lakes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract Mono Lake is a hypersaline alkaline lake in the high altitude Great Basin desert of eastern California. Algal productivity of the lake is nitrogen-limited, and a contributing source is derived from benthic nitrogen fixation. Lake level and salinity have fluctuated with natural climatic variations but have also been affected by the diversion of tributary streams. This research examines the influence of varied salinity and lake level on the potential for benthic nitrogen fixation in Mono Lake. A sediment-surface microbial mat community was exposed directly, and in acclimated cultures, to a range of Mono Lake salinities under anaerobic incubations and the activity of nitrogenase assayed by acetylene reduction. Activity was stimulated in light, but also occurred in darkness. Over an experimental salinity range from 50 to 150 g L-1 TDS, nitrogenase activity was reduced by 90 per crnt, with the activity persisting at the highest salinity being attributable to dark fixation alone. Between a salinity of 50 g L-1, occurring in Mono Lake over 50 years ago, and 100 g L-1, nitrogenase activity was reduced by nearly half. Changes in the area of the littoral zone at varied lake levels also affect the total amount of potential benthic nitrogen fixation in the lake. An accounting of yearly inputs of nitrogen to Mono Lake suggests N2-fixation could contribute as much as 76–81 percent of the total. Inhibition of nitrogen fixation rates by increased salinity could limit the long-term nutrient supply and benthic primary productivity of this ecosystem.
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    URL: http://dx.doi.org/10.1023/A:1009001514449
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    Numerical prognosis for salinity profiles of future lakes in the opencast mine Merseburg-Ost (1998)
    Springer
    International journal of salt lake research 7 (1998), S. 235-260 
    Details
    ISSN: 1573-8590
    Keywords: groundwater ; Merseburg-Ost ; mine ; meromixis ; numerical model ; monimolimnion ; opencast ; physical limnology ; salinity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract Salt-laden groundwater inflows have formed monimolimnia in developing lakes of the abandoned opencast lignite mine Merseburg-Ost, Central Germany. Water-levels are still rising. To predict the future status of the lakes, two numerical models were developed. One was designed to predict groundwater flows, the second included limnophysical processes. The models were run in parallel and data exchange between them was performed every 1 to 10 years of model time. A trial of a 100-years prognosis was done. The results of surface salinity, mixing depth, and salinity profile are given. A sensitivity analysis yielded indications for the accuracy of the prediction.
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    URL: http://dx.doi.org/10.1007/BF02441877
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    Is salinity the only water quality parameter affected when saline water is disposed in rivers? (1998)
    Springer
    International journal of salt lake research 7 (1998), S. 285-299 
    Details
    ISSN: 1573-8590
    Keywords: nutrients ; salinity ; water quality
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract The effect of saline lake water disposal from the Lough Calvert Drainage Scheme on water quality of the Barwon River, in south west Victoria, Australia, was investigated. The Scheme is used to regulate the levels of several saline lakes outside the Barwon's catchment. This study found that the disposal of saline lake water was associated with increased total phosphorus, PO4, TKN, suspended solids, electrical conductivity and stream discharge and lower NOx in the Barwon River. Thus, when disposing of saline water, factors other than salinity should be considered in order to prevent an impact on the aquatic environment. At present this is generally not done. The results are discussed with reference to the effects of saline water disposal on aquatic biota and how the effect of saline lake water disposal on water quality may differ from the disposal of saline groundwater.
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    URL: http://dx.doi.org/10.1023/A:1009023515649
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    Is salinity the only water quality parameter affected when saline water is disposed in rivers? (1998)
    Springer
    International journal of salt lake research 7 (1998), S. 285-300 
    Details
    ISSN: 1573-8590
    Keywords: nutrients ; salinity ; water quality
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract The effect of saline lake water disposal from the Lough Calvert Drainage Scheme on water quality of the Barwon River, in south west Victoria, Australia, was investigated. The Scheme is used to regulate the levels of several saline lakes outside the Barwon's catchment. This study found that the disposal of saline lake water was associated with increased total phosphorus, PO4, TKN, suspended solids, electrical conductivity and stream discharge and lower NOx in the Barwon River. Thus, when disposing of saline water, factors other than salinity should be considered in order to prevent an impact on the aquatic environment. At present this is generally not done. The results are discussed with reference to the effects of saline water disposal on aquatic biota and how the effect of saline lake water disposal on water quality may differ from the disposal of saline groundwater.
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    URL: http://dx.doi.org/10.1007/BF02442141
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    The relationship between electrical conductivity and selected macroinvertebrate communities in four river systems of south-west Victoria, Australia (1998)
    Springer
    International journal of salt lake research 7 (1998), S. 153-170 
    Details
    ISSN: 1573-8590
    Keywords: confounding parameters ; nutrients ; salinity ; survey design
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract In order to relate macroinvertebrate fauna to electrical conductivity (EC), a survey of selected orders of macroinvertebrates was conducted in the Glenelg, Hopkins, Merri and Barwon River Catchments in south-west Victoria, Australia. The survey consisted of sampling 21 paired sites at confluences of streams. There was little difference between the in-stream habitat but there was a range of differences in EC between each of the paired sites. The dissimilarity of macroinvertebrate fauna between the paired sites was compared to the proportional difference in EC and other water quality variables (dissolved oxygen, water temperature, pH, NO2-N, NO3-N, PO4 and turbidity). This allowed the elimination of EC being confounded with geographical scale parameters and took into account other water quality parameters that may be confounded with EC. A positive relationship was found between the dissimilarity of the fauna at each of the two paired sites and the proportional difference in EC. No such relationship was found for any other measured water quality variable. The results of this survey show that macroinvertebrate community structure is associated with EC of the river systems investigated after eliminating large scale geographical patterns, in-stream habitat and the measured water quality parameters.
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    URL: http://dx.doi.org/10.1023/A:1009019404720
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    The phenology of fine root growth in a maple-dominated ecosystem: relationships with some soil properties (1998)
    Springer
    Plant and soil 201 (1998), S. 59-69 
    Details
    ISSN: 1573-5036
    Keywords: maple ; moisture ; phenology ; root growth ; soil fertility ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A two-year study was undertaken in a maple-dominated watershed of southern Québec, Canada, to examine relationships between trends in fine root growth, stem diameter growth, soil moisture, soil temperature, mineralized-N and extractable-P. Until September, soil temperature was consistently higher in 1995 than in 1994. Apart from the first sampling in mid-May, soil moisture was higher in 1994 than in 1995. In 1994, most fine roots were produced before leaf expansion, whereas in 1995, fine root production peaked in July. Annual fine root production was estimated to be 2.7 times higher in 1994 than in 1995. Stem growth was strongly associated with the seasonal and annual variation in soil temperature. Root and diameter growth were asynchronous in 1994 but not in 1995. Fine root production was associated with two groups of variables: a soil fertility (mineralized-N and extractable-P) group and a physical soil environment (moisture and temperature) group. Our results are consistent with the negative effect of high soil-N fertility on fine root production but are inconclusive as to the positive effect of high soil-P fertility. Soil conditions that are detrimental to root growth such as high N availability and anaerobiosis could modify the normal dynamics of fine root growth.
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    URL: http://dx.doi.org/10.1023/A:1004351705516
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    The influence of salinity on growth, biomass production and photosynthesis of Eucalyptus camaldulensis Dehnh. and Dalbergia sissoo Roxb. seedlings (1998)
    Springer
    Plant and soil 205 (1998), S. 163-169 
    Details
    ISSN: 1573-5036
    Keywords: biomass ; growth ; photosynthesis ; salinity ; salt-tolerance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The influence of NaCl salinity on growth, dry-matter production and leaf photosynthesis of seedlings of Eucalyptus camaldulensis Dehnh. and Dalbergia sissoo Roxb. was studied by imposing 4 levels (40, 80, 120 and 160 mM) of NaCl in pot culture. Salinity up to 160 mM did not affect plant survival, but did affect plant growth and dry-matter production depending upon the species and salt concentration. NaCl reduced leaf number and dry-weight of all the plant components, but increased stem dry-weight, especially in E. camaldulensis. Salinization also stimulated total dry-matter production at all the salinity levels in E. camaldulensis but only at 40 mM in D. sissoo. The two species varied in protein and chlorophyll concentration and in leaf photosynthetic rate. Protein and chlorophyll concentration of the plants fell at all the levels of NaCl, except at 40 mM, where stimulation in the photosynthetic carbon assimilation of the plants occurred. However, no distinct relationship between leaf photosynthetic rate and dry-matter production was found. The study indicated that low salt concentrations generally stimulated growth, biomass production and rate of photosynthesis in both the species, and E. camaldulensis appeared more NaCl salt-tolerant than D. sissoo.
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    URL: http://dx.doi.org/10.1023/A:1004381021039
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    Root and shoot elongation of rhizotron-grown seedlings of Eucalyptus nitens and Eucalyptus globulus in relation to temperature (1998)
    Springer
    Plant and soil 206 (1998), S. 37-46 
    Details
    ISSN: 1573-5036
    Keywords: Eucalyptus globulus ; Eucalyptus nitens ; root apical diameter ; root elongation ; shoot elongation ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Information on the growth response of a crop plant in relation to temperature can be helpful in selecting genotypes to suit local environments, scheduling favourable time of planting and forecasting growth and yield. To determine the effects of varying temperature on root and shoot elongation of eucalypt seedlings, elongation rates of roots and shoots were measured in rhizotrons for two species (Eucalyptus nitens (Deane and Maiden) Maiden, and Eucalyptus globulus Labill.) at a temperature range of 5–23 °C. Within this range of temperatures, elongation rates of roots and shoots of both species increased with an increase in temperature. Roots of E. globulus were more sensitive and shoots less sensitive to temperature than those of E. nitens. However, the threshold temperature corresponding with zero elongation rate predicted from the regression of elongation rate against temperature was similar for the roots (∼5 °C) and shoots (∼0 °C) of both species. Hysteresis did not appear to have a significant influence on root or shoot elongation of both species during warming compared with cooling. Results are discussed highlighting the importance of the interaction between development and growth of plant components.
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    URL: http://dx.doi.org/10.1023/A:1004337121719
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    Desert perennials as plant and soil indicators in Eastern Arabia (1998)
    Springer
    Plant and soil 199 (1998), S. 261-266 
    Details
    ISSN: 1573-5036
    Keywords: Abu Dhabi ; salinity ; soil surface hardness ; soil texture ; vegetation types
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Soils of different Eastern Arabian vegetation types, dominated by five desert perennials have been analysed for their texture, salinity and surface hardness. The vegetation types were analysed for plant species richness and composition. Special emphasis was given to Abu Dhabi's widespread terrestrial perennials Cyperus conglomeratus Rottb., Haloxylon salicornicum (Moq.) Bge., Pennisetum divisum (Gmel.) Henr., Seidlitzia rosmarinus Ehrenb. ex Bge. and Zygophyllum mandavillei Hadidi. The results show some important relationships between soils and plants. C. conglomeratus indicates the lowest soil salinity levels and the finest texture. P. divisum indicates the highest species richness and S. rosmarinus indicates the lowest species richness. Z. mandavillei indicates the highest salinity levels, the largest soil particle size, and the hardest soil surfaces.
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    URL: http://dx.doi.org/10.1023/A:1004318610230
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    Effects of sulfate on cadmium uptake by Swiss chard: II. Effects due to sulfate addition to soil (1998)
    Springer
    Plant and soil 202 (1998), S. 217-222 
    Details
    ISSN: 1573-5036
    Keywords: Cd2+ activity ; Cd–SO4 interaction ; nutrient solution ; salinity ; speciation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Sulfate complexation of Cd in nutrient solution has been shown to have little impact on Cd uptake by plants. This study examined the effect of sulfate added to soil on Cd concentrations in soil solution and Cd uptake by Swiss chard (Beta vulgaris L. cv. Fordhook Giant). Swiss chard was grown in soil which was wetted with complete nutrient solution containing equivalent salt concentrations of NaNO3 or Na2SO4. Plant growth was reduced by increasing both NO3 and SO4 concentrations in soil solution, with growth reductions similar for both salts. The Cd concentration in soil solution increased P〈 0.05) more consistently with increasing concentrations of SO4 compared to NO3 in soil solution. Solution speciation, calculated with GEOCHEM-PC, showed significant increases of Cd2+ activities with increasing salt rates. Shoot Cd content in 19-day-old Swiss chard plants was marginally but significantly P 〈0.05) increased with increasing SO4 concentration but no effect was observed with increasing NO3 concentration. These results are compared with earlier work on the marked effect of Cl- salinity on Cd availability in Swiss chard. Possible mechanisms explaining the smaller effect of SO4 compared to Cl on Cd availability are proposed.
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    URL: http://dx.doi.org/10.1023/A:1004381413048
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    Effects of sulfate on cadmium uptake by Swiss chard: I. Effects of complexation and calcium competition in nutrient solutions (1998)
    Springer
    Plant and soil 202 (1998), S. 211-216 
    Details
    ISSN: 1573-5036
    Keywords: Cd2+ activity ; Cd–SO4 interaction ; nutrient solution ; salinity ; speciation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The impacts of both sulfate (SO4) and calcium (Ca) concentrations in solution on plant uptake of cadmium (Cd) vary according to effects on both sorption of Cd by soil and on uptake by the plant root. This study investigated how complexation of Cd by SO4 affected plant Cd uptake in nutrient solution. Swiss chard (Beta vulgaris L. cv. Fordhook Giant) was grown in nutrient solution with SO4 concentrations varying between 8 mM and 58 m M, with ionic strength maintained constant across treatments using nitrate (NO3). In a separate experiment, solution Ca concentrations was also varied to compensate for SO4 complexation by Ca. Plant growth was unaffected by increasing SO4 concentrations in solution. Despite considerable reductions in free Cd2+ ion activities in solution by increasing SO4 concentrations, plant Cd concentrations were unaffected. Similarly, plant Cd concentrations were unaffected by increasing Ca concentrations in solution to compensate for SO4 complexation of Ca. These data suggest that the CdSO40 complex is taken up by plants with equal efficiency to the free Cd2+ ion.
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    URL: http://dx.doi.org/10.1023/A:1004333529886
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    Decomposition of seawater-irrigated halophytes: implications for potential carbon storage (1998)
    Springer
    Plant and soil 202 (1998), S. 241-250 
    Details
    ISSN: 1573-5036
    Keywords: carbon storage ; decomposition ; halophyte ; salinity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Seawater-irrigated halophytes are a non-traditional crop that may serve to offset anthropogenic carbon dioxide emissions through long-term carbon storage. To assess the feasibility of storing carbon as cultivated halophyte residues in coastal desert soils, the decay rate, microbial activity and microbial decomposer abundance of post-harvest residues were investigated for three potential halophyte crops. Decay rates were determined by measuring weight loss from residues in litterbags in both the field and laboratory. The effect of incorporating residues into the soil was examined by locating litterbags both on and below the soil surface. Microbial decomposition activity was measured as the CO2 efflux from residue amended soil columns in the greenhouse. The abundance of bacteria, fungi, and nematodes was assessed in decomposing residues using litterbags in the field. The three halophytes decomposed at rates similar to those of conventional, non-saline residues (0.20–0.30% d-1) whether placed on the surface or buried at 30 cm. Residue type affected microbial activity in soil columns during the first 21 days, but decomposition was similar for the three halophytes thereafter. Residue type affected the abundance of nematodes, but not of bacterial and fungal decomposers. Because the rate of halophyte residue decay and the number of microbial decomposers associated with the residues are similar to those of fresh water systems, there appears to be no advantage in storing carbon as plant residue in this saline agricultural system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004360422347
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    The response of soil microorganisms and roots to elevated CO2 and temperature in a terrestrial model ecosystem (1998)
    Springer
    Plant and soil 202 (1998), S. 251-262 
    Details
    ISSN: 1573-5036
    Keywords: climate change ; Ecotron ; microbial biomass ; microbial community structure ; soil enzymes ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract We investigate the response of soil microorganisms to atmospheric CO2 and temperature change within model terrestrial ecosystems in the Ecotron. The model communities consisted of four plant species (Cardamine hirsuta, Poa annua, Senecio vulgaris, Spergula arvensis), four herbivorous insect species (two aphids, a leaf-miner, and a whitefly) and their parasitoids, snails, earthworms, woodlice, soil-dwelling Collembola (springtails), nematodes and soil microorganisms (bacteria, fungi, mycorrhizae and Protista). In two successive experiments, the effects of elevated temperature (ambient plus 2 °C) at both ambient and elevated CO2 conditions (ambient plus 200 ppm) were investigated. A 40:60 sand:Surrey loam mixture with relatively low nutrient levels was used. Each experiment ran for 9 months and soil microbial biomass (Cmic and Nmic), soil microbial community (fungal and bacterial phospholipid fatty acids), basal respiration, and enzymes involved in the carbon cycling (xylanase, trehalase) were measured at depths of 0–2, 0–10 and 10–20 cm. In addition, root biomass and tissue C:N ratio were determined to provide information on the amount and quality of substrates for microbial growth. Elevated temperature under both ambient and elevated CO2 did not show consistent treatment effects. Elevation of air temperature at ambient CO2 induced an increase in Cmic of the 0–10 cm layer, while at elevated CO2 total phospholipid fatty acids (PLFA) increased after the third generation. The metabolic quotient qCO2 decreased at elevated temperature in the ambient CO2 run. Xylanase and trehalase showed no changes in both runs. Root biomass and C:N ratio were not influenced by elevated temperature in ambient CO2. In elevated CO2, however, elevated temperature reduced root biomass in the 0–10 cm and 30–40 cm layers and increased N content of roots in the deeper layers. The different response of root biomass and C:N ratio to elevated temperature may be caused by differences in the dynamics of root decomposition and/or in allocation patterns to coarse or fine roots (i.e. storage vs. resource capture functions). Overall, our data suggests that in soils of low nutrient availability, the effects of climate change on the soil microbial community and processes are likely to be minimal and largely unpredicatable.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004309623256
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    Predominance of ecophysiological controls on soil CO2 flux in a Minnesota grassland (1998)
    Springer
    Plant and soil 207 (1998), S. 77-86 
    Details
    ISSN: 1573-5036
    Keywords: Cedar Creek ; Minnesota ; light ; root respiration ; Scizachyrium scorparium ; soil CO2 flux ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Ecosystem studies often study soil CO2 flux as a function of environmental factors, such as temperature, that affect respiration rates by changing the rate of utilization of carbon substrates. These studies tend not to include factors, such as photosynthesis, that affect the supply of carbon substrates to roots and root-associated processes. We examined the role of decreased carbohydrate source on soil CO2 flux and root respiration in an annually-burned grassland through manipulations of light intensity and removal of above ground biomass. We also quantified the contribution of root respiration to soil CO2 flux by measuring the respiration rates of excised roots. Two days of shading caused a 40% reduction in soil CO2 flux, while clipping was associated with a 19% reduction in soil CO2 flux. Both reductions were independent of soil and air temperature at the time of measurement. The relative decrease in soil CO2 flux observed in the clipping experiment was similar in magnitude to an observed decrease in root respiration per gram of root, linking decreased root activity and soil CO2 flux. From these experiments, we conclude that variation in factors that affect carbon availability to roots can be important determinants of soil CO2 flux and should be included explicitly in studies that measure or model soil CO2 flux.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004417419288
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    Sodium and potassium uptake of rice panicles as affected by salinity and season in relation to yield and yield components (1998)
    Springer
    Plant and soil 207 (1998), S. 133-145 
    Details
    ISSN: 1573-5036
    Keywords: genotypic differences ; humidity effects ; panicle transpiration ; salinity ; salt resistance ; spikelet sterility ; yield components
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Salinity is a major yield-reducing stress in many arid and/or coastal irrigation systems for rice. Past studies on salt stress have mainly addressed the vegetative growth stage of rice, and little is known on salt effects on the reproductive organs. Sodium and potassium uptake of panicles was studied for eight rice cultivars in field trials under irrigation with saline and fresh water in the hot dry season and the wet season 1994 at WARDA in Ndiaye, Senegal. Sodium and potassium content was determined at four different stages of panicle development and related to salt treatment effects on yield, yield components and panicle transpiration. Yield and yield components were strongly affected by salinity, the effects being stronger in the HDS than in the WS. The cultivars differed in the amount of salt taken up by the panicle. Tolerant cultivars had lower panicle sodium content at all panicle development stages than susceptible ones. Panicle potassium concentration decreased with panicle development under both treatments in all cultivars, but to a lesser extent in salt treated susceptible cultivars. Grain weight reduction in the early panicle development stages and spikelet sterility increase in the later PDS were highly correlated (p 〈 0.01) with an increase in panicle sodium concentration in both seasons, whereas reduction in spikelet number was not. The magnitude of salt-induced yield loss could not be explained with increases in sodium uptake to the panicle alone. It is argued that the amount of sodium taken up by the panicle may be determined by two different factors. One factor (before flowering) being the overall control mechanism of sodium uptake through root properties and the subsequent distribution of sodium in the vegetative plant, whereas the other (from flowering onwards) is probably linked to panicle transpiration.
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    URL: http://dx.doi.org/10.1023/A:1026407913216
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    Does tolerance of wheat to salinity and hypoxia correlate with root dehydrogenase activities or aerenchyma formation? (1998)
    Springer
    Plant and soil 201 (1998), S. 275-284 
    Details
    ISSN: 1573-5036
    Keywords: ADH ; aerenchyma ; hypoxia ; LDH ; salinity ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The effects of NaCl salinity (100 or 150 mol m-3) and hypoxia on seedlings of several wheat varieties (Lyallpur-90, SARC-1, Pato, Tchere, Pb-85, Siete Cerros, Chinese Spring and a Chinese Spring × Thinopyrum elongatum amphidiploid) were studied in solution culture. In vivo studies of activities of different enzymes (alcohol dehydrogenase (ADH), lactate dehydrogenase (LDH) and cytochrome oxidase (COase)) extracted from Pato and Pb-85 included the effect of salinity with and without hypoxia, while during in vitro studies, NaCl, glycinebetaine and proline were added to the assay mixture. The extent of aerenchyma formation was also determined in Pato, Chinese Spring and a Chinese Spring × Thinopyrum elongatum amphidiploid. Imposition of hypoxia greatly induced ADH and LDH activity in roots of wheat seedlings after a week-long exposure. However, exposure of roots to salinity also slightly increased LDH and ADH activity compared with the non-saline control. On a relative basis, Pato had higher ADH activity under hypoxic (21×) or saline-hypoxic stress (20×) than in aerated conditions. Hypoxia alone or in the presence of salts decreased COase activity in both Pato and Pb-85. The in vitro studies revealed that NaCl (on an equimolar basis at up to 500 mol m-3) is more disruptive than glycinebetaine or proline. LDH was more sensitive to NaCl than ADH. Aerenchyma development was higher near the root-shoot interface compared to near the root tip. Salinity under hypoxic conditions significantly reduced aerenchyma development near the root tip and root-shoot interface compared to hypoxia alone. Neither enzyme activity nor aerenchyma formation could account for varietal differences in tolerance to hypoxia alone or in combination with salinity.
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    URL: http://dx.doi.org/10.1023/A:1004333318973
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    Ice nucleation in fruit juice from different varieties of sea buckthorn Hippophaë rhamnoides L. (1998)
    Springer
    Euphytica 102 (1998), S. 117-124 
    Details
    ISSN: 1573-5060
    Keywords: sea buckthorn ; climate ; freezing ; germination ; ice nucleators ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The main aim of the investigation was to study the effects of climate on the ice nucleation temperatures of fruit juice from sea buckthorn, Hippophaë rhamnoides L. This could provide information on possible adaptive values of ice nucleators in the fruits. It was also an aim to provide information on ice nucleation of fruit juice from different varieties of sea buckthorn. This was done to find suitable varieties for agricultural production of ice nucleator containing fruit juice. Such food grade ice nucleators can be used in the processing of food stuffs particularly where large ice crystals are desired. The ice nucleation temperatures were low in juice from unripe fruits in the summer, and peaked at − 6 °C in the autumn. There were no significant differences in nucleation temperatures in juice from fruits grown along a climatic gradient along the Trondheimsfjord. Juice from varieties originating from different parts of the world, but grown at the same fields, showed different mean nucleation temperatures, ranging from − 15.1 °C in a Swiss wild type of subsp. fluviatilis to − 6.1 °C in a Swedish wild type of subsp. rhamnoides. Varieties with very potent nucleators (− 2 °C to − 3 °C) were found, but these nucleators were present in low concentrations. Varieties with high concentration of nucleators within a small temperature range (− 6 °C to − 7 °C) were also found. No correlation between geographic origin and nucleation temperatures was found. Depending on conditions, freezing the fruits had either no, or a negative effect on the germination success. Since no adaptive benefit to the sea buckthorn could be demonstrated, the nucleating ability of the fruit juice is probably incidental.
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    URL: http://dx.doi.org/10.1023/A:1018336413479
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    Effect of heat shock during grain filling on protein composition and technological quality of wheats (1998)
    Springer
    Euphytica 100 (1998), S. 147-154 
    Details
    ISSN: 1573-5060
    Keywords: wheat quality ; temperature ; heat shock ; polymeric protein ; nitrogen application ; breadmaking quality
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract In southern Europe, the Mediterranean climate offers a unique opportunity for the production of high quality wheats, which are lacking in the European Economic Union. It is also responsible for the remarkable variability in both wheat yield and quality from year to year and from location to location. In this paper, the effects (in recent years) of the Mediterranean climate in Italy on grain yield and quality of bread and durum wheats are summarised with particular regard to high temperatures. Nitrogen fertilisation rate and timing were investigated in five cultivars grown at six sites. The impact of high temperature was evaluated in open field and pot experiments by imposing different temperature regimes during grain filling. Viscoelastic properties were evaluated with the Chopin alveograph for field experiments and with a Promylograph T3 apparatus for pot experiments. Protein composition was evaluated by SE-HPLC (size exclusion high performance liquid chromatrography). Agronomic trials indicated that high quality wheats can be obtained in a wide range of growing conditions. Viscoelastic properties were significantly affected by the temperature treatments. Short episodes of daily maximum temperatures above 35 °C caused a 'weakening' in both durum and bread wheat. High temperatures seemed to affect mainly the composition of the polymeric fraction (soluble/insoluble polymers) without influencing their synthesis.
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    URL: http://dx.doi.org/10.1023/A:1018353300618
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    Magnetometric Method of Investigating Fire Sites (1997)
    Springer
    Fire technology 33 (1997), S. 195-213 
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    ISSN: 1572-8099
    Keywords: point of fire origin ; fire ; temperature ; plaster ; concrete ; thermal ; damage ; biotite ; magnetization ; susceptibility ; N-rays ; P-rays ; X-rays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying
    Notes: Abstract Magnetic susceptibility (MS) measurements were taken to determine fire exposure patterns on noncombustible structural members and compartment boundaries. These measurements led on-site fire investigators to the cause of combustion and the point of fire origin. Thermal damage to walls and to ceilings was estimated quantitatively by measuring MS and two-valent Fe ion concentration in building materials such as concrete and plaster. It was shown that these effects are preconditioned by thermochemical transformations in the mineral biotite, which is present as a component of common building materials. For the first time, the effect of a substantial and irreversible increase in biotite magnetization exposed to powerful flows of N- and P-rays was found. It is hoped that the presence of this “magnetic trace” of radiation in building materials will allow investigators to use the magnetometric method at nuclear power plant catastrophes such as that in Chernobyl. It was also shown that the influence of N- and P-rays on biotite's magnetic properties greatly differs from the thermal influence on biotite.
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    URL: http://dx.doi.org/10.1023/A:1015363605037
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    Effect of time-dependent speed on frictional heat generation and wear in transient axisymmetrical contact of sliding (1997)
    Springer
    Archive of applied mechanics 67 (1997), S. 331-338 
    Details
    ISSN: 1432-0681
    Keywords: Key words frictional heating ; wear ; contact pressure ; temperature ; brake system
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary A transient contact problem with frictional heating and wear for two nonuniform sliding half-spaces is considered. One of the two half-spaces is assumed to be slightly curved to give a Hertzian initial pressure distribution: the other is a rigid nonconductor. Under the assumption that the contact pressure distribution could be described by Hertz formulas during all the process of interaction, the problem is formulated in terms of one integral equation of Volterra type with unknown radius of contact area. A numerical solution of this equation is obtained using a piecewise-constant presentation of an unknown function. The influence of operating parameters on the contact temperature and the radius of the contact area is studied.
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    URL: http://dx.doi.org/10.1007/s004190050121
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    The effect of condensation on sporulation ofHelminthosporium solani on potato tubers infected with silver scurf and held in simulated store conditions (1997)
    Springer
    Potato research 40 (1997), S. 169-180 
    Details
    ISSN: 1871-4528
    Keywords: skin resistance ; temperature ; Solanum tuberosum L.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Chambers were designed to simulate environmental conditions present in commercial potato stores and were used to introduce condensation to tubers infected with silver scurf (Helminthosporium solani). The electrical resistance measured across the skin of tubers from the top of the chambers was consistently lower than that from the bottom of the chamber, and this was reflected in an increased number ofH. solani spores produced by the top tubers. An increase in the length of the condensation period resulted in the skin resistance remaining lower for a longer period and also resulted in higher number of spores. Tubers held at relatively high ambient temperatures (15 °C) required a shorter period of condensation to cause an increase in spore count. This investigation highlighted the need for close monitoring of store environments so that condensation events can be quickly identified and the tubers dried.
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    URL: http://dx.doi.org/10.1007/BF02358243
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    The effect of some environmental factors on potato tuber numbers (1997)
    Springer
    Potato research 40 (1997), S. 297-306 
    Details
    ISSN: 1871-4528
    Keywords: light ; temperature ; stolon growth medium ; below ground nodes ; Solanum tuberosum L.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Five experiments studied the effects of shading, temperature and stolon growth medium on stolon and tuber formation. The lowest numbers of stolons and tubers were produced at the higher and lower nodes. Numbers of primary stolons and tubers were relatively stable across nodes and treatments and variation in total numbers was largely due to changes in numbers of lateral and branch stolons. In the field, 70% shading reduced numbers of stolons and tubers by reducing lateral and branch stolons, while in hydroponics, 45% shading and temperatures at initiation had no effect on tuber numbers. In both environments later planting tended to reduce numbers of stolons and tubers. There were large effects of the physical environment, with compost producing three times as many tubers as dry vermiculite. The potential number of tubers may be determined by the number of stolons and the environmental conditions affecting stolon formation and development.
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    URL: http://dx.doi.org/10.1007/BF02358011
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    Variability in biomarkers of different saline basins in China (1997)
    Springer
    International journal of salt lake research 6 (1997), S. 25-53 
    Details
    ISSN: 1573-8590
    Keywords: biomarker ; palaeoenvironment ; salinity ; salt lake ; sulfur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract 42 samples (sediments and crude oils) from 5 differentsaline/hypersaline basins of China were examined using variety ofgeochemical techniques. A pronounced even over odd distribution of n-alkanesis observed for the Ejinur, Jianghan samples. Abundance of isoprenoidalkanes, dominated by phytane (C20 up to 20 per cent inEOM), and C25 and C30 components isanother outstanding feature of these studied lacustrine hypersalinesettings, indicating important contributuions from archaebacteria.Gammacerane is a major component of some Eocene Jianghan samples andCretaceous Taian sediments. Absolute concentration of phytane andgammacerane appears to be linearly related to chlorine and residual(reduced) sulfur contents of sediments from Jianghan basin, suggestingsulfur incoporation might have played an important role in the enhacement ofthese biomarkers in the anoxic hypersaline, alkaline settings. Wide range oforganic sulfur compounds in immature samples of Jianghan Basin reflects asignificant pathway for sulfur incorporation under hypersaline, extremelyanoxic/reducing conditions, although for some structures a direct originfrom some sulfur archaebacteria can not be excluded. Brackish salt marshsediment and oil from Lenghu depression contain abundant lupane, strong OEPin n-alkane series, and predominance of C29 steranes,suggesting a markedly input from vascular higher plants. The marginal marineevaporate sediments from the hypersaline Triassic Yangtze Platform is uniquefor its predominant, complete series of isoprenoid alkanes up toC36 (abundant) and C40 (trace). Theselong-chain isoprenoids are probably derived from phytoplanktons in additionto archaebacteria. The marked difference in biomarker distributions from thevarious suites of samples support that application of these biomarkers tohelp effectively characterize different saline basins. The molecularvariation is, however, not only due to their discrepancy in biologicalsources, but also the extension of sulfate reduction and the availability ofmetal ions during early diagenesis.
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    URL: http://dx.doi.org/10.1023/A:1009038107589
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    Variability in biomarkers of different saline basins in China (1997)
    Springer
    International journal of salt lake research 6 (1997), S. 25-53 
    Details
    ISSN: 1573-8590
    Keywords: biomarker ; palaeoenvironment ; salinity ; salt lake ; sulfur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract 42 samples (sediments and crude oils) from 5 different saline/hypersaline basins of China were examined using variety of geochemical techniques. A pronounced even over odd distribution ofn-alkanes is observed for the Ejinur, Jianghan samples. Abundance of isoprenoid alkanes, dominated by phytane (C20 up to 20 per cent in EOM), and C25 and C30 components is another outstanding feature of these studied lacustrine hypersaline settings, indicating important contributuions from archaebacteria. Gammacerane is a major component of some Eocene Jiangham samples and Cretaceous Taian sediments. Absolute concentration of phytane and gammacerane appears to be linearly related to chlorine and residual (reduced) sulfur contents of sediments from Jianghan basin, suggesting sulfur incoporation might have played an important role in the enhacement of these biomarkers in the anoxic hypersaline, alkaline settings. Wide range of organic sulfur compounds in immature samples of Jianghan Basin reflects a significant pathway for sulfur incorporation under hypersaline, extremely anoxic/reducing conditions, although for some structures a direct origin from some sulfur archaebacteria can not be excluded. Brackish salt marsh sediment and oil from Lenghu depression contain abundant lupane, strong OEP inn-alkane series, and predominance of C29 steranes, suggesting a markedly input from vascular higher plants. The marginal marine evaporate sediments from the hypersaline Triassic Yangtze Platform is unique for its predominant, complete series of isoprenoid alkanes up to C36 (abundant) and C40 (trace). These long-chain isoprenoids are probably derived from phytoplanktons in addition to archaebacteria. The marked difference in biomarker distributions from the various suites of samples support that application of these biomarkers to help effectively characterize different saline basins. The molecular variation is, however, not only due to their discrepancy in biological sources, but also the extension of sulfate reduction and the availability of metal ions during early diagenesis.
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    The analysis of nitrate in highly saline waters (1997)
    Springer
    International journal of salt lake research 6 (1997), S. 269-278 
    Details
    ISSN: 1573-8590
    Keywords: nitrate analysis ; salt effect ; salinity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract The analysis of nitrate in seawater and hypersalinewaters should take account of a significant “salteffect”. Procedures developed for fresh water andmarine waters must be applied cautiously to highlysaline waters. The most widely used standard methodfor the determination of nitrate-nitrogen (NO3-N)in fresh and marine waters involves the quantitativereduction of nitrate by the Cd column techniquefollowed by colorimetric procedures. In our study,three approaches to estimate NO3-N in highlysaline waters were examined. The first involveddilution. This approach overcame the salt effect butdilution limited the detection of low concentrationsof nitrate in highly saline waters. The secondinvolved the use of standard nitrate solutions insaline water. This method is not recommended becauseof nitrate impurities in AR grade salts. The third-and preferred approach-involved the use of standardadditions. “Spikes” of a known volume of NO3-Nstandard solution were added to natural saline waters. Nitrate values estimated by the standard additionmethod were used to calculate an equation for salterror correction at different salinities applicable towaters with the same relative ionic composition asseawater. This could then be used to correct nitratedeterminations in highly saline waters where standardsmade in distilled water were used for calibration.Many previously published data for NO3-N insaline water used methods of analysis which do nottake account of salt error and are therefore probablyin error.
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    URL: http://dx.doi.org/10.1023/A:1009008120817
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    The analysis of nitrate in highly saline waters (1997)
    Springer
    International journal of salt lake research 6 (1997), S. 269-278 
    Details
    ISSN: 1573-8590
    Keywords: nitrate analysis ; salt effect ; salinity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract The analysis of nitrate in seawater and hypersaline waters should take account of a significant “salt effect”. Procedures developed for fresh water and marine waters must be applied cautiously to highly saline waters. The most widely used standard method for the determination of nitrate-nitrogen (NO3-N) in fresh and marine waters involves the quantitative reduction of nitrate by the Cd column technique followed by colorimetric procedures. In our study, three approaches to estimate NO3-N in highly saline waters were examined. The first involved dilution. This approach overcame the salt effect but dilution limited the detection of low concentrations of nitrate in highly saline waters. The second involved the use of standard nitrate solutions in saline water. This method is not recommended because of nitrate impurities in AR grade salts. The third- and preferred approach-involved the use of standard additions. “Spikes” of a known volume of NO3-N standard solution were added to natural saline waters. Nitrate values estimated by the stadard addition method were used to calculate an equation for salt error correction at different salinities applicable to waters with the same relative ionic composition as seawater. This could then be used to correct nitrate determinations in highly saline waters where standards made in distilled water were used for calibration. Many previously published data for NO3-N in saline water used methods of analysis which do not take account of salt error and are therefore probably in error.
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    URL: http://dx.doi.org/10.1007/BF02449929
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    Midge-and diatom-based palaeosalinity reconstructions for Mahoney Lake, Okanagan Valley, British Columbia, Canada (1997)
    Springer
    International journal of salt lake research 6 (1997), S. 249-267 
    Details
    ISSN: 1573-8590
    Keywords: Chironanidae ; diatoms ; palaeoclimate ; palaeolimnology ; palaeoecology ; palaeosalinity ; salinity ; postglacial ; climate change
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract Salinity fluctuations in lakes of semi-arid regions have long been recognised as indicators of palaeoclimatic change, and have provided a valuable line of evidence in palaeo-climatic reconstruction. In the present study, fossil remains of diatoms and midges were used to reconstruct salinity changes at Mahoney Lake from the early postglacial, through the early, mid and late Holocene. A transition from midges typical of a freshwater community (Protanypus, Sergentia, Heterotrissocladius, Cladopelma, Dicrotendipes) during the early postglacial, to those indicative of saline environments (Cricotopus/Orthocladius, Tanypus) occurred in the early Holocene. The midge-inferred salinity values reflected the shift from freshwater (0.031 g/L) immediately after deglaciation, to saline water (2.4 to 55.2 g/L) in subsequent periods. A less saline period was found to have occurred after 1000 yr BP, suggesting a cooler or wetter period. The diatom record indicates similar trends, with freshwater taxa (e.g.,Cyclotella bodanica var. aff.lemanica) dominating near the bottom of the core. Diatom-inferred salinities indicate that saline conditions (about 30 g/L) prevailed throughout subsequent Holocene time, although relatively fresh conditions are indicated following deposition of the Mazama Ash, and from about 1500 yr BP until the present day. Midge and diatom-inferred salinity reconstructions for Mahoney Lake compare favorably with each other, and with climate trends inferred from earlier palynological evidence. The palaeosalinity record thus contributes new data relevant to past climatic conditions, in a region where little data have previously been collected.
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    Midge- and diatom-based palaeosalinity reconstructions for Mahoney Lake, Okanagan Valley, British Columbia, Canada (1997)
    Springer
    International journal of salt lake research 6 (1997), S. 249-267 
    Details
    ISSN: 1573-8590
    Keywords: Chironanidae ; diatoms ; palaeoclimate ; palaeolimnology ; palaeoecology ; palaeosalinity ; salinity ; postglacial ; climate change
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract Salinity fluctuations in lakes of semi-arid regions have long beenrecognised as indicators of palaeoclimatic change, and have provided avaluable line of evidence in palaeoclimatic reconstruction. In the presentstudy, fossil remains of diatoms and midges were used to reconstructsalinity changes at Mahoney Lake from the early postglacial, through theearly, mid and late Holocene. A transition from midges typical of afreshwater community (Protanypus, Sergentia, Heterotrissocladius,Cladopelma, Dicrotendipes) during the early postglacial, to those indicativeof saline environments (Cricotopus/Orthocladius, Tanypus) occurred in theearly Holocene. The midge-inferred salinity values reflected the shift fromfreshwater (0.031 g/L) immediately after deglaciation, to saline water (2.4to 55.2 g/L) in subsequent periods. A less saline period was found to haveoccurred after 1000 yr BP, suggesting a cooler or wetter period. The diatomrecord indicates similar trends, with freshwater taxa (e.g., Cyclotellabodanica var. aff. lemanica) dominating near the bottom of the core.Diatom-inferred salinities indicate that saline conditions (about 30 g/L)prevailed throughout subsequent Holocene time, although relatively freshconditions are indicated following deposition of the Mazama Ash, and fromabout 1500 yr BP until the present day. Midge and diatom-inferred salinityreconstructions for Mahoney Lake compare favorably with each other, and withclimate trends inferred from earlier palynological evidence. Thepalaeosalinity record thus contributes new data relevant to past climaticconditions, in a region where little data have previously been collected.
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    URL: http://dx.doi.org/10.1023/A:1009056003978
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    Factors affecting germination of oospores of Peronospora viciae f.sp. pisi in vitro (1997)
    Springer
    European journal of plant pathology 103 (1997), S. 573-580 
    Details
    ISSN: 1573-8469
    Keywords: Pisum sativum ; host plant exudates ; light ; temperature ; infection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The effects of host plant exudates, light and temperature on germination of oospores of Peronospora viciae f.sp. pisi in vitro were investigated. Seed and root exudates did not increase percentage germination, whereas light inhibited germination. The first germ tubes appeared after 4, 7, and 14 days of incubation at 15, 10 and 5 °C, respectively. The eventual level of germination was highest and had similar values at 5 and 10 °C. At 20 °C germination was poor and at 25 °C no germination was observed. Oospores placed on membrane filters were incubated on soil. When oospores were retrieved from the membrane filters after six days and placed in water at 10 °C, they germinated within 2 days. On soil significantly less oospores germinated than in water. Germinability of oospores stored in the dark at 5 or 20 °C at 30 or 76% RH was studied over a two-year period. Germinability generally increased over time, but fluctuations were observed indicating the occurrence of secondary dormancy. Time courses of germinability were generally similar for oospores stored at several temperatures and humidities. No effect of light on time course of germinability was found when oospores were exposed to alternating light-dark periods or stored in continuous dark for 140 days. Percentage germination observed in a germination assay was correlated with percentage infection determined in a bioassay.
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    URL: http://dx.doi.org/10.1023/A:1008607100742
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  • 86
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    Micellization of triblock copoly(ethyleneoxide/tetrahydrofuran/ethylene oxide) (1997)
    Springer
    Colloid & polymer science 275 (1997), S. 467-473 
    Details
    ISSN: 1435-1536
    Keywords: Key words Block copolymers ; micelle ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract  The association behaviour of triblock copoly(ethylene oxide/tetrahydrofuran/ethylene oxide), in particular E100T27E100, in aqueous solutions has been investigated by means of static and dynamic light scattering, nuclear magnetic reso-nance (NMR) and surface tension techniques. On raising the polymer concentration at room temperature, the copolymer aggregates to form micelles with an aggregation number of about 105 (R G, mic≈15 nm and R H, mic≈13 nm, as revealed by light scattering and FT-PGSE NMR measurements, respectively). The micelles are kinetically quite stable, the micellar lifetime is shown to be more than 1 h. The residence time of a single unimer in a micelle is more than 140 ms. The apparent radius of gyration R G, mic is fairly independent of concentration, but large effects are observed on varying the temperature. Raising the temperature initially results in an increase of the apparent micellar size, followed by a maximum at an intermediate temperature (≈45 °C). At higher temperatures a contraction of the micelles is observed. The shape of the micelles also appear to vary in this temperature interval. The interactions responsible for these phenomena are discussed in terms of, e.g., the temperature-dependent solubility of the alkylene oxide segments in water and polydispersity effects.
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    URL: http://dx.doi.org/10.1007/s003960050105
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    Purslane (Portulaca oleracea L.): A halophytic crop for drainage water reuse systems (1997)
    Springer
    Plant and soil 192 (1997), S. 277-283 
    Details
    ISSN: 1573-5036
    Keywords: leaf areas ; salinity ; sand cultures ; selenium ; water use
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Drainage water reuse systems have been proposed for the west side of the San Joaquin Valley of California in order to reduce the volumes of water requiring disposal. Implementation of this system requires development of a cropping system with successively higher salt tolerance. A major limitation is the need to identify alternate species that will be suitable as the final, most salt tolerant crop in the series. These crops must be productive when irrigated with waters that are typically high in sulfate salinity and may be contaminated with potentially toxic trace elements. This study was initiated to evaluate the interactive effects of sulfate salinity and selenium on biomass production and mineral content of purslane (Portulaca oleracea). Plants were grown in greenhouse sand cultures and irrigated four times daily. Treatments consisted of three salinity levels with electrical conductivities (ECi) of 2.1, 15.2, and 28.5 dS m−1, and two selenium levels, 0 and 2.3 mg L−1. In the initial harvests, shoot dry matter was reduced by 15 to 30% at 15.2 dS m−1 and by 80 to 90% at 28.5 dS m−1. Regrowth after clipping above the first node was vigorous and biomass from plants irrigated with 15.2 dS m−1 water was nearly double that from the 2 dS m−1 treatment. Purslane appears to be an excellent candidate for inclusion in saline drainage water reuse systems. It is (i) highly tolerant of both chloride- and sulfate-dominated salinities, (ii) a moderate selenium accumulator in the sulfate-system, and (iii) a valuable, nutritive vegetable crop for human consumption and for livestock forage.
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    URL: http://dx.doi.org/10.1023/A:1004276804529
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    Mineralisation of nitrogen from an incorporated catch crop at low temperatures: experiment and simulation (1997)
    Springer
    Plant and soil 188 (1997), S. 211-219 
    Details
    ISSN: 1573-5036
    Keywords: catch crop ; mineralisation ; nitrogen ; simulation model ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The release of nitrogen from incorporated catch crop material in winter is strongly influenced by soil temperatures. A laboratory experiment was carried out to investigate this influence in the range of 1-15 °C. Samples of sandy soil or a mixture of sandy soil with rye shoots were incubated at 1-5-10-15 °C, and samples of sandy soil with rye roots were incubated at 5-10-15 °C. Concentrations of Nmin (NH4 +-N and NO3 --N) were measured after 0-1-2-4-7-10 weeks for the sandy soil and the sandy soil:rye shoot mixture, and after 0-2-7-10 weeks for the sandy soil:rye root mixture. At 1 °C, 20% of total organic N in the crop material had been mineralised after ten weeks, indicating that mineralisation at low temperatures is not negligible. Maximum mineralisation occurred at 15 °C; after ten weeks, it was 39% of total applied organic nitrogen from shoot and 35% from root material. The time course of mineralisation was calculated using an exponential decay function. It was found that the influence of temperature in the range 1-15 °C could be described by the Arrhenius equation, stating a linear increase of ln(k) with T-1, k being the relative mineralisation rate in day-1 and T the temperature (°C). A simulation model was developed in which decomposition, mineralisation and nitrification were modelled as one step processes, following first order kinetics. The relative decomposition rate was influenced by soil temperature and soil moisture content, and the mineralisation of N was calculated from the decomposition of C, the C to N ratio of the catch crop material and the C to N ratio of the microbial biomass. The model was validated first with the results of the experiment. The model was further validated with the results of an independent field experiment, with temperatures fluctuating between 3 and 20 °C. The simulated time course of mineralisation differed significantly from the experimental values, due to an underestimation of the mineralisation during the first weeks of incubation.
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    URL: http://dx.doi.org/10.1023/A:1004255102840
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    Root elongation in saline solution related to calcium binding to root cell plasma membranes (1997)
    Springer
    Plant and soil 191 (1997), S. 67-76 
    Details
    ISSN: 1573-5036
    Keywords: calcium ; plasma membrane ; root elongation ; salinity ; sodium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract To gain a better understanding of the relations between root elongation and the amount of Ca2+ bound to the plasma membrane (PM), melon plants were grown in aerated solutions containing different concentrations of CaCl2 with various concentrations of NaCl or mannitol. With increasing external concentrations of NaCl or mannitol, root elongation was suppressed. Addition of CaCl2 to the external medium alleviated the inhibition of root elongation by high concentrations of Na+, but not of mannitol. Root elongation in media containing high concentrations of NaCl was correlated with the computed amount of Ca2+ bound to the PM. A model describing relative root elongation (RRL) under salt stress was developed. This model takes into account the osmotic potential in the growing solution (based on the mannitol experiments) and the computed amount of Ca2+ bound to the PM. Calcium binding was calculated by applying a Gouy-Chapman-Stern sorption model using the same parameters deduced from studies on PM vesicles. This model combines electrostatic theory with competitive binding at the PM surface. The model for RRL allowed the computation of a critical value for the fraction of negative sites binding Ca2+ on the PM needed for nearly optimal (95%) root elongation. Any decrease below this critical value decreased the RRL. Root elongation of Honey Dew (salt-resistant cv.) was greater than that of Eshkolit Ha'Amaqim (salt-sensitive cv.) under NaCl stress. Nearly optimal root growth for Honey Dew and Eshkolit Ha'Amaqim occurred when 40% and 51% of total membrane charged sites were bound by Ca2+, respectively. The effect of osmotic potential on the suppression of root elongation was the same for the two cultivars. To our knowledge, this report provides the first fully quantitative estimates of PM-bound Ca2+ relative to salt toxicity.
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    URL: http://dx.doi.org/10.1023/A:1004241506347
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    Morphology and tissue quality of seedling root systems of Pinus taeda and Pinus ponderosa as affected by varying CO2, temperature, and nitrogen (1997)
    Springer
    Plant and soil 195 (1997), S. 107-119 
    Details
    ISSN: 1573-5036
    Keywords: carbohydrates ; carbon dioxide ; nitrogen ; nutrients ; roots ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Rising atmospheric carbon dioxide, nitrogen deposition and warmer temperatures may alter the quantity and quality of plant-derived organic matter available to soil biota, potentially altering rates of belowground herbivory and decomposition. Our objective was to simulate future growth conditions for an early successional (loblolly) and late successional (ponderosa) species of pine to determine if the physical and chemical properties of the root systems would change. Seedlings were grown for 160 days in greenhouses at the Duke University Phytotron at 35 or 70 Pa CO2 partial pressure, ambient or ambient + 5 °C temperature, and 1 or 5 mMNH4O3. Roots from harvested seedlings were analyzed for changes in surface area, specific root length, mass, total nonstructural carbohydrates (TNC), and concentrations of macro-nutrients. Surface area increased in both species under elevated CO2, due primarily to increases in root length, and this response was greatest (+138%) in loblolly pine at high temperature. Specific root length decreased in loblolly pine at elevated CO2 but increases in mass more than compensated for this, resulting in net increases in total length. TNC was unaffected and nutrient concentrations decreased only slightly at elevated CO2, possibly from anatomical changes to the root tissues. We conclude that future growth conditions will enhance soil exploration by some species of pine, but root carbohydrate levels and nutrient concentrations will not be greatly affected, leaving rates of root herbivory and decomposition unaltered.
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    URL: http://dx.doi.org/10.1023/A:1004291430748
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    Temperature-induced alteration to root longevity in Lolium perenne (1997)
    Springer
    Plant and soil 190 (1997), S. 87-90 
    Details
    ISSN: 1573-5036
    Keywords: minirhizotron ; root longevity ; root mortality ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The production and mortality of roots is an important factor determining nutrient and carbon fluxes in terrestrial ecosystems. However, the effect of temperature on the longevity of roots is not understood. In this study the impact of changes in temperature on the longevity of Lolium perenne roots was determined. Plants were grown at 15 °C, 21 °C and 27 °C and their roots observed using a minirhizotron system. Major effects of temperature were measured with large reductions in root longevity occurring at higher temperatures. The implications of these data are discussed.
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    URL: http://dx.doi.org/10.1023/A:1004298804353
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    Is salinity tolerance related to Na accumulation in Upland cotton (Gossypium hirsutum) seedlings? (1997)
    Springer
    Plant and soil 190 (1997), S. 67-75 
    Details
    ISSN: 1573-5036
    Keywords: cotton ; Gossypium hirsutum ; potassium ; salinity ; sodium ; tolerance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Physiological responses to salt stress were studied in two cotton cultivars previously selected on the basis of growth under salinity. Plants were grown in nutrient solutions under controlled conditions. In the first experiment, the genotypes were grown at different salt concentrations (0, 100 and 200 mt M NaCl) and growth rates, water contents and ion accumulation were determined. In a second experiment, both genotypes were grown at the same salt concentration (200 mt M NaCl). Dry matter partitioning in individual leaves, stem and roots, water contents, specific leaf area (SLA), ion accumulation (K+, Na+, Cl−) and leaf water potentials were measured. Finally, an experiment with low salt levels (2.7 and 27 mt M NaCl) was run to compare K and Na+ uptake and distribution. There were no differences in growth between the cultivars in the absence of salt stress, whereas under stress genotype Z407 had higher leaf area and dry matter accumulation than P792. Leaf water potential and leaf water content were lower in cv P792 than in cv Z407. There were no significant differences in the levels of Cl− accumulation between genotypes. The main feature of the tolerant genotype (Z407) was a higher accumulation of Na+ in leaves and an apparent capacity for K+ redistribution to younger leaves. We postulate that the higher tolerance in Z407 is the result of several traits such as a higher Na+ uptake and water content. Adaptation through adequate, but tightly controlled ion uptake, typical of some halophytes, matched with efficient ion compartmentation and redistribution, would result in an improved water uptake capacity under salt stress and lead to maintenance of higher growth rates.
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    URL: http://dx.doi.org/10.1023/A:1004214825946
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    Nutrient relations of the halophytic shrub, Sarcobatus vermiculatus, along a soil salinity gradient (1997)
    Springer
    Plant and soil 190 (1997), S. 105-117 
    Details
    ISSN: 1573-5036
    Keywords: greasewood ; magnesium potassium ; salinity ; selectivity ; sodium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Recent water level declines of a saline and alkaline lake (Mono Lake, California, USA) have exposed large areas of former lake bottom substrates that have been sparsely colonized by the halophytic shrub, Sarcobatus vermiculatus. To increase understanding of the interaction of salt and nutrient relations in halophytes we investigated spatial and seasonal patterns of leaf elemental composition and growth for Sarcobatus along an extreme salinity gradient using four sites varying in age since exposure. Soil and groundwater Na and EC increased from non-saline at the site farthest from the Lake to highly saline at the site closest to the Lake. Leaf and stem length growth declined along this same transect. In June, when shoot growth rates were maximal, leaf Na paralleled substrate availability and reached a high of 130 g kg−1 leaf dry weight near the Lake. Through the remainder of the growing season, plants on the lower salinity site continued to accumulate increasing amounts of leaf Na, whereas plants at the highest salinity site reached a plateau earlier in the season. The similarity of high leaf Na at all sites by the end of the season indicates a dominance of Na nutrition over the entire gradient, and a possible upper bound of Na accumulation and tolerance for this species. In June, Sarcobatus leaf N, P were higher at sites further from the Lake and did not correspond to soil N (total) and P that were highest near the Lake. Leaf K, Ca, and Mg in June also did not match substrate availability, and were low enough to indicate marginal sufficiency for growth. However, the increasing substrate Na did not interfere with K, Ca and Mg uptake based on selectivity coefficients (e.g. (leaf K/leaf Na)/ (soil K/soil Na)) that did not decline with increasing substrate salinity. Uptake and transport to leaves, of K and Ca relative to Na, remained proportional to what was in the soil across the entire gradient of soil salinity. Uptake and transport of Mg relative to Na increased dramatically in inverse proportion to declining soil availability near the Lake, indicating that Mg may be a critical limiting factor for tolerance of high salinity sites. The key determinants of Sarcobatus growth and ecological dominance along this extreme salinity gradient (non-saline to highly saline) are the propensity to accumulate large amounts of leaf Na over the entire gradient, and the ability to maintain adequate uptake of N, P, K, Ca, and Mg under highly variable substrate combinations of nutrients and Na.
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    URL: http://dx.doi.org/10.1023/A:1004211207079
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    The effect of salinity on corn yield using the CERES-maize model (1997)
    Springer
    Irrigation and drainage systems 11 (1997), S. 15-28 
    Details
    ISSN: 1573-0654
    Keywords: corn yield ; modelling ; salinity ; simulation ; soil water availability ; wilting point
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract In most cases, when calculating soil water availability, only thewater content is considered. The effect of salinity on the wiltingpoint is neglected. The objective of this work is to use asimulation model (CERES-maize) in order to predict cornyields as a function of water salinity under severalenvironmental, agrotechnical, and plant characteristics. A modelis presented in which the wilting point is a function of the soilsalt content. At high salinity, the water content at wilting pointis higher than at low salinity, resulting in an insufficient amountof available water and, therefore, a reduced yield. The modelwas used to simulate several theoretical and experimentalsituations for forage corn and grain corn. Simulation resultsshowed that nitrogen fertilization increases the salinity thresholdvalue and the yield sensitivity (rate of yield reduction per unitof salinity). The also showed that forage corn is more sensitiveto salinity than grain corn. If the soil is not leached, a heaviersoil texture has a higher salinity threshold value. On the otherhand, if the soil is leached, the soil texture has no influence onthe salinity threshold value and the yield is less sensitive tosalinity in sandy soils. The determination coefficient (r2= 0.75) indicated that the results of the simulations were in goodagreement with the field data.
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    Temperature effect on shear induced transition in surfactant solution (1997)
    Springer
    Colloid & polymer science 105 (1997), S. 322-325 
    Details
    ISSN: 1435-1536
    Keywords: Rheology ; surfactant solutions ; micelles ; phase transition ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Aqueous solutions of cationic surfactant with binding counterions exhibit a transition under shear. In this paper the steady shear properties of semidilute aqueous micellar solutions (cetylpyridinium chloride and sodium salicylate in brine) are presented as a function of concentration and temperature. The shear thinning behavior of this system could be described by the Carreau model at low shear rate and by a power law at higher shear rate. The temperature dependence of the zero shear viscosity follows an Arrhenius relationship. The critical shear rate at which the viscosity departs from its zero shear value is found to increase with temperature indicating the influence of this parameter on transition.
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    URL: http://dx.doi.org/10.1007/BF01188972
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    Effect of pre-incubation humidity and temperature treatment on the in vitro germination of avocado pollen grains (1997)
    Springer
    Euphytica 94 (1997), S. 247-251 
    Details
    ISSN: 1573-5060
    Keywords: Persea americana ; avocado humidity ; Greece ; pollen grain germination ; temperature ; fruit-set
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Optimum in vitro germination of pollen grain of the avocado cultivars Fuerte, Nabal, Ettinger, Bacon and Zutano occurred at 25 °C. However, there were significant differences between cultivars in percentage germination and relative humidity (RH) requirements for optimum pollen grain growth. The most sensitive cultivar to relative humidity was Fuerte, in which the germination of pollen grain rose from 11.4%, at 40% RH, to about 50%, after one hour at 100% RH. The germination% of Nabal pollen grain was already high at 40% RH and was not increased by higher relative humidity. Increased relative humidity also helped to sustain the viability of avocado pollen. At 30 °C and 5% RH the pollen grains of Fuerte quickly lost its ability to germinate, at 40% RH for 1 hour, germination was reduced spectacularly compared to pollen kept in saturated with moisture environment where it was not affected the first 24 hours. The effects of temperature and relative humidity on fruit-set and yield of avocado are discussed.
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    URL: http://dx.doi.org/10.1023/A:1002917915386
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    Animal Consciousness and Ethics in Asia and the Pacific (1997)
    Springer
    Journal of agricultural and environmental ethics 10 (1997), S. 249-267 
    Details
    ISSN: 1573-322X
    Keywords: Animals ; Asia ; consciousness ; Australia ; Hong Kong ; India ; Israel ; Japan ; New Zealand ; The Philippines ; Russia ; Singapore ; Thailand
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Philosophy
    Notes: Abstract The interactions between humans, animals and the environment have shaped human values and ethics, not only the genes that we are made of. The animal rights movement challenges human beings to reconsider interactions between humans and other animals, and maybe connected to the environmental movement that begs us to recognize the fact that there are symbiotic relationships between humans and all other organisms. The first part of this paper looks at types of bioethics, the implications of autonomy and the value of being alive. Then the level of consciousness of these relationships are explored in survey results from Asia and the Pacific, especially in the 1993 International Bioethics Survey conducted in Australia, Hong Kong, India, Israel, Japan, New Zealand, The Philippines, Russia, Singapore and Thailand. Very few mentioned animal consciousness in the survey, but there were more biocentric comments in Australia and Japan; and more comments with the idea of harmony including humans in Thailand. Comparisons between questions and surveys will also be made, in an attempt to describe what people imagine animal consciousness to be, and whether this relates to human ethics of the relationships.
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    URL: http://dx.doi.org/10.1023/A:1007774409131
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    Phosphorus supplying capacity of heavily fertilized soils II. Dry matter yield of successive crops and phosphorus uptake at different temperatures (1996)
    Springer
    Nutrient cycling in agroecosystems 47 (1996), S. 123-134 
    Details
    ISSN: 1573-0867
    Keywords: heavily fertilized soils ; P supplying capacity ; P uptake ; residual P ; soil test methods ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Nine heavily fertilized soils were collected from southern and central Norway. A greenhouse experiment in the phytotron was conducted to evaluate the P supplying capacities of these soils at different temperatures (9, 12 and 18 °C). The crops were grown in succession and the sequence was oat, rye grass (cut twice), oat, rape and oat. Effect of temperature on dry matter (DM) yield and P uptake was more marked up to the fourth crop but the effect varied among crops. The DM yields of oat and rape increased with increasing temperature but the opposite was the case with rye grass. The yield differences among soils at 12 °C were highly significant (p 〈 0.01) in contrast to 9 and 18 °C. The amount of P taken up by plants in these soils was highest at 18. °C. The P supplying capacity was highest in the soils with higher content of organic P. Generally, the soils of very fine and coarse texture classes failed to supply enough P to crops to avoid P deficiency in the successive crops. Soil P test (P-NH4-lactate) values in most of the soils increased with increasing temperatures. The highest temperature effect was seen in the Særheim sand soil. Soil P test extractants P-AL, Bray-1 and Colwell-P were used to determine P in the soil after each harvest and the soil P test values were compared with P uptake by crops. Only the P-AL extractant was significantly correlated to cumulative P removal (CPR) by plants in most of the soils. Regression equation was calculated for each soil. The value of removed P per harvest (RPH) varied from 10.33 to 20.87 mg P kg−1 soil. Phosphorus drawdown slope was determined for each soil and the number of consecutive harvests necessary to reduce the P-AL value to a normal level (110 mg P kg−1 soil) was calculated. The drawdown slope varied widely (1.257–2.801) and this reflected the P buffer capacity and the number of crops required to lower the soil test P value to a normal level. The highest drawdown slope was found in the soils with higher P supplying capacities. The Bray-1 extractant was significantly correlated in the soils with higher buffer capacity but the Colwell-P method did not show significant correlation in any of the soils.
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    URL: http://dx.doi.org/10.1007/BF01991544
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    Effects of temperature on nutrient release from slow-release fertilizers (1996)
    Springer
    Nutrient cycling in agroecosystems 46 (1996), S. 179-187 
    Details
    ISSN: 1573-0867
    Keywords: electrical conductivity ; leaching ; nitrogen ; pH ; phosphorus ; potassium ; release pattern ; slow-release fertilizers ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract We studied the effect of temperature on the release of N, P, and K from slow-release fertilizers (SRF). The study was conducted in micro-lysimeters filled with moist peat medium. Increasing the temperature from 4 to 12°C slightly increased N release from three different slow-release N (SRN) carriers with different particle sizes and coating thicknesses. At 21°C the rate of release was significantly different than the other two temperatures. Urea formaldehyde (UF), sulphur coated urea (SCU) and coated calcium nitrate (CCN), incubated in sphagnum moss peat, released between 3 and 20% of the applied N in six weeks. For eight synthetic and organic NPK carriers, the release pattern was similar to UF and SCU. However, the leaching losses of N from the NPK fertilizers were up to twenty times more than for the SRN products. Except for Osmocote® and Duna, which released 30–40% of the applied N as mineral-N within six weeks, all other slow-release and slowly mineralized NPK carriers acted like readily water-soluble compound NPK. Temperature did not affect the nutrient release from NPK fertilizers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00420552
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    Electronic Resource
    Electronic Resource
    Powdered elemental sulphur: oxidation rate, temperature dependence and modelling (1996)
    Springer
    Nutrient cycling in agroecosystems 47 (1996), S. 19-28 
    Details
    ISSN: 1573-0867
    Keywords: elemental sulphur ; model ; oxidation rate ; particle size distribution ; soil ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Finely-powdered elemental sulphur is a useful source of fertilizer S, being readily oxidizable in soil to plant-available sulphate yet possessing some slow release characteristics. Two mesh sizes were evaluated using four soils from northeast Scotland. Particle size analysis found that the 120 and 300 mesh S samples had specific surface areas of 1300 and 1940 cm2 g−1, respectively, with most of the surface area in particles of 10 – 20 µm diameter. The S oxidation rate was similar in all four soils but was greater for the 300 mesh than for the 120 mesh S: mean values of 51% and 18% were oxidized over 7 weeks at 14 °C, respectively. The time course of oxidation followed a sigmoidal pattern with a pronounced lag which was modelled using the logistic equation. Maximum specific oxidation rates were 11–28 µg S cm−2 day−2 for the 300 mesh S at 14 °C. These were significantly slower at 7 °C and the temperature response was calculated as a Q10 of 4.0. A model of seasonal S oxidation was developed using a cosine function for the annual temperature, the Arrhenius equation to relate S oxidation rate to temperature and a generalization of the logistic equation to describe the time course of S oxidation. Simulations showed that the 300 mesh S would be useful for spring S applications in east Scotland and if applied in autumn could supply S during the autumn and again in the spring. The 120 mesh S would be less effective in autumn but more resistant to winter leaching. The 120 mesh S applied to the warmer soils of southwest England would behave the same as 300 mesh S applied in east Scotland.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01985715
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