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  • 1
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    Seasonal Forecasts, Climatic Change and Human Health : Health and Climate (2008)
    Springer
    Details
    Keywords: Assessment ; Malaria ; Public Health ; Scale ; Weather ; climate change ; public health policy ; temperature
    Description / Table of Contents: Awareness that many key aspects of public health are strongly influenced by climate is growing dramatically, driven by new research and experience and fears of climate change and the research needed to underpin policy developments in area is growing rapidly . This awareness has yet to translate into a practical use of climate knowledge by health policy-makers. Evidence based policy and practice is the mantra of the health sector. If climate scientists are to contribute effectively to health policy at local and global scales then careful empirical studies must be undertaken – focused on the needs of the public health policy and decision-makers. Results presented at the Wengen conference make clear that the science and art of integrating climate knowledge into the control of climate sensitive diseases on a year to year time frame as well as careful assessments of the potential impacts of climate change on health outcomes over longer time frames is advancing rapidly on many fronts. This includes advances in the empirical understanding of mechanisms, methodologies for modeling future impacts, new partnership developments between the health and climate community along with access to relevant data resources, and education and training. In a rapidly evolving field this book provides a snapshot of these emerging themes.
    Pages: Online-Ressource (X, 232 pages)
    ISBN: 9781402068775
    URL: https://doi.org/10.1007/978-1-4020-6877-5
    Language: English
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    E-BOOK
  • 2
    Electronic Resource
    Electronic Resource
    Rubber stoppers used with sulphidic media: a note of caution (2000)
    Springer
    World journal of microbiology and biotechnology 16 (2000), S. 571-572 
    Details
    ISSN: 1573-0972
    Keywords: Anaerobes ; hydrogen sulphide ; rubber stoppers ; sulphate reduction ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Common black rubber stoppers, made from natural rubber and styrene–butadiene, may cause a loss of hydrogen sulphide from aqueous media and impede the growth of sulphate-reducing bacteria under thermophilic conditions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008909530445
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  • 3
    Electronic Resource
    Electronic Resource
    Effects of temperature, water activity and gas atmosphere on mycelial growth of tempe fungi Rhizopus microsporus var. microsporus and R. microsporus var. oligosporus (2000)
    Springer
    World journal of microbiology and biotechnology 16 (2000), S. 853-858 
    Details
    ISSN: 1573-0972
    Keywords: Carbondioxide ; fungi ; oxygen ; Rhizopus ; solid-substrate fermentation SSF ; tempe modelling ; temperature ; water activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Rhizopus microsporus var. microsporus and var. oligosporus are used in the manufacture of various Asian fermented foods (tempe, black oncom, sufu). In view of solid-substrate fermentation (SSF) control, mycelial growth of strains of both varieties was tested for sensitivity to fluctuations of temperature, water activity and interstitial gas composition. This was achieved by measuring radial growth as well as biomass dry weight of pre-germinated microcolonies on defined media. The optimum conditions were temperature 40 °C, a w 0.995 and a gas composition of air for the growth of both strains on a model medium. Whereas radial growth rates of var. microsporus and var. oligosporus were similar, biomass growth rates of var. oligosporus were higher than those of var. microsporus under optimum conditions. The temperature-dependent growth of Rhizopus spp. at a w 〉 0.98 could be described by the Ratkowsky Equation. Carbon dioxide (5–10% v/v) inhibited the growth of Rhizopus spp. at non-limiting levels of oxygen. The two strains were able to grow at low (0.5% v/v) oxygen levels, but the mycelial density was rather low. No interrelation of water activity and gas composition was observed, but at high water activity the fungi were more sensitive to changes of temperature. The implications for process control are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008974621698
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  • 4
    Electronic Resource
    Electronic Resource
    Studies on anaerobic proteolytic bacteria of Leh, India (2000)
    Springer
    World journal of microbiology and biotechnology 16 (2000), S. 297-301 
    Details
    ISSN: 1573-0972
    Keywords: Anaerobic bacteria ; growth ; protease ; psychrotrophs ; temperature ; volatile fatty acids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Five anaerobic proteolytic bacteria were isolated from water bodies of Leh, India, where the ambient temperature varies from −25 to 25 °C. Isolates showed growth at all temperatures ranging from 5 to 37 °C except SPL-4 and SPL-5 which showed no growth at 5 °C. The cultures could grow and produce proteases on various protein substrates and the yield varied with the substrates. Two of the cultures showed the presence of spores. Acetate was the dominant VFA during hydrolysis of protein substrates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008935425175
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  • 5
    Electronic Resource
    Electronic Resource
    Patulin and aflatoxin in brown rot lesion of apple fruits and their regulation (2000)
    Springer
    World journal of microbiology and biotechnology 16 (2000), S. 607-612 
    Details
    ISSN: 1573-0972
    Keywords: Aflatoxin ; apple ; fruit oils ; fungi ; patulin ; sodium hypochlorite ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Aspergillus flavus, A. niger, Penicillium expansum and Rhizopus stolonifer were the most frequently isolated fungi from healthy apple fruits. Alternaria alternata was the most common organism of rotten apple fruits, followed by A. niger, A. flavus, P. expansum and R. stolonifer. The prevalent type of decay, brown rot lesion, is caused by R. stolonifer followed by A. flavus, A. niger, A. alternata and P. expansum. Sodium hypochlorite had good curative properties against fruit rots. The main natural mycotoxins produced in rotten apple were patulin and aflatoxins. The optimum temperature for patulin production by P. expansum was 15 °C after 15 days. Complete inhibition of patulin formation was attained using 0.2% lemon oil and 〉 90% inhibition using 0.05% lemon and 0.2% orange oils. Also significant inhibition (〉 90%) of aflatoxin production was observed with 0.2% lemon oil.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008982511653
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  • 6
    Electronic Resource
    Electronic Resource
    Temperature effects on egg size and their fitness consequences in the yellow dung fly Scathophaga stercoraria (2000)
    Springer
    Evolutionary ecology 14 (2000), S. 627-643 
    Details
    ISSN: 1573-8477
    Keywords: adaptation ; Bergmann's rule ; clutch size ; egg size ; physiological constraint ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Organisms and parts of an organism like eggs or individual cells developing in colder environments tend to grow bigger. A unifying explanation for this Bergmann's rule extended to ectotherms has not been found, and whether this is an adaptive response or a physiological constraint is debated. The dependence of egg and clutch size on the mother's temperature environment were investigated in the yellow dung fly Scathophaga stercoraria. Smaller eggs were laid at warmer temperatures in the field and the laboratory, where possible confounding variables were controlled for. As clutch size at the same time was unaffected by temperature, this effect was not due to a trade-off between egg size and number. Temperature-dependent egg sizes even persisted within individuals: when females were transferred to a cooler (warmer) environment, they laid third-clutch eggs that were larger (smaller) than their first-clutch eggs. The fitness consequences of these temperature-mediated egg sizes were further investigated in two laboratory experiments. Neither egg and pre-adult survivorship nor larval growth rate were maximized, nor was development time minimized, at the ambient temperature corresponding to the mother's temperature environment. This does not support the beneficial acclimation hypothesis. Instead, this study yielded some, but by no means conclusive indications of best performance by offspring from eggs laid at intermediate temperatures, weakly supporting the optimal temperature hypothesis. In one experiment the smaller eggs laid at 24°C had reduced survivorship at all ambient temperatures tested. Smaller eggs thus generally performed poorly. The most parsimonious interpretation of these results is that temperature-mediated variation in egg size is a maternal physiological response (perhaps even a constraint) of unclear adaptive value.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1010911017700
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  • 7
    Electronic Resource
    Electronic Resource
    Metabolism of Poly-β-Hydroxybutyric Acid in Yersinia pseudotuberculosis and Listeria monocytogenes Cultivated at Different Temperatures (2000)
    Springer
    Microbiology 69 (2000), S. 652-654 
    Details
    ISSN: 1608-3237
    Keywords: poly-β-hydroxybutyric acid ; Yersinia pseudotuberculosis ; Listeria monocytogenes ; temperature ; growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A comparative investigation of the intracellular content of poly-β-hydroxybutyric acid showed that Yersinia pseudotuberculosis strains accumulated, on the average, lower amounts of this reserve substance than Listeria monocytogenes strains. The intracellular pool of poly-β-hydroxybutyric acid was responsible for the growth of the bacteria at low temperatures (4–6°C) in the absence of any exogenous carbon and energy source.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026645922491
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  • 8
    Electronic Resource
    Electronic Resource
    Optimization of Maintenance Conditions for Some Microforms of Red Algae in Collections (2000)
    Springer
    Russian journal of plant physiology 47 (2000), S. 779-785 
    Details
    ISSN: 1608-3407
    Keywords: red microalgae ; collection of algae ; maintenance conditions ; darkness ; temperature ; chlorophyll fluorescence ; phycobiliproteins ; viability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effects of light and temperature conditions on the maintenance of some red microalgae (order Porphyridiales) in collections were studied. Periodical subculturing on solid and liquid media was used for maintenance. Halophilic species P. aeruginosa, P. cruentum, and P. sordidum were lost in 2.5 months if kept in darkness. The viability of algae in the dim light slightly declined in 4–5 months and was species-dependent. The results were compared with earlier obtained data on mesophilic Chlorococcales. For the green algae, darkness proved to be the optimal condition, while their viability markedly decreased at light. It was suggested that this discrepancy was caused by the presence of phycobiliproteins in the cells of red algae. Dim light conditions are optimal for the synthesis of phycobiliproteins, which are rapidly destroyed in darkness, thus leading to cell death.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026611312844
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  • 9
    Electronic Resource
    Electronic Resource
    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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  • 10
    Electronic Resource
    Electronic Resource
    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026505329762
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  • 11
    Electronic Resource
    Electronic Resource
    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026528727365
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  • 12
    Electronic Resource
    Electronic Resource
    Ultraviolet Rayleigh Lidar for Wind and Temperature Measurements (2000)
    Springer
    Optical review 7 (2000), S. 555-560 
    Details
    ISSN: 1349-9432
    Keywords: lidar ; remote sensing ; Rayleigh scattering ; wind ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A new method of simultaneous remote sensing of atmospheric wind and temperature by a ultraviolet Rayleigh lidar is described. This technique uses two narrowband filters located at either side of the wings of the Rayleigh backscatter spectrum to analyze Rayleigh backscattering signals. These filters are selected to be greatly sensitive to both velocity and temperature. By measuring the ratio and the sum of the two normalized filtered signals, the line-of-sight wind velocity and temperature profiles can be retrieved. A lidar system is proposed for the wind velocity and temperature measurements in the middle atmosphere, and the simulation results show that the accuracies of velocity and temperature are about 1 m/s and 2 K at the height of 30 km, respectively. The influence of aerosol component has been estimated for clear weather conditions, and with an uncertainty of aerosol component of 15% the errors are about 0.1 m/s and 2 K above the troposphere, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s10043-000-0555-2
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  • 13
    Electronic Resource
    Electronic Resource
    A Fiber Optic Wavelength Modulation Sensor Based on Tantalum Pentoxide Coatings for Absolute Temperature Measurements (2000)
    Springer
    Optical review 7 (2000), S. 205-208 
    Details
    ISSN: 1349-9432
    Keywords: optical fibres ; temperature ; sensors ; tantalum pentoxide ; thermal optic ; thermal expansion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A fiber optic low-coherence sensor based on the spectral shift of tantalum pentoxide thin films for absolute temperature sensing up to 650°C is described. A tantalum pentoxide single layer was deposited directly onto the cleaved end-face of a single mode optical fibre and was illuminated with an super luminescence diode (SLD) source through a directional coupler. Interference fringes of the film on reflection were obtained within the optical bandwidth of the SLD using an optical spectrum analyser. The spectral shift versus temperature rise showed no turning points and the output was unambiguous, linear, monotonic and gave about 0.016 nm wavelength shift in the spectrum per°C. A semi-empirical calibration procedure based on the refractive index (n) and thickness (l) of the tantalum pentoxide film for absolute thermometric measurements is described.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s10043-000-0205-8
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  • 14
    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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  • 15
    Electronic Resource
    Electronic Resource
    Diatom transfer-functions for quantifying past air temperature, pH and total organic carbon concentration from lakes in northern Sweden (2000)
    Springer
    Journal of paleolimnology 24 (2000), S. 109-123 
    Details
    ISSN: 1573-0417
    Keywords: diatoms ; climate change ; temperature ; pH ; transfer functions ; lake sediments
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences
    Notes: Abstract The relationships between diatoms (Bacillariophyceae) in surface sediments of lakes and summer air temperature, pH and total organic carbon concentration (TOC) were explored along a steep climatic gradient in northern Sweden to provide a tool to infer past climate conditions from sediment cores. The study sites are in an area with low human impact and range from boreal forest to alpine tundra. Canonical correspondence analysis (CCA) constrained to mean July air temperature and pH clearly showed that diatom community composition was different between lakes situated in conifer-, mountain birch- and alpine-vegetation zones. As a consequence, diatoms and multivariate ordination methods can be used to infer past changes in treeline position and dominant forest type. Quantitative inference models were developed to estimate mean July air temperature, pH and TOC from sedimentary diatom assemblages using weighted averaging (WA) and weighted averaging partial least squares (WA-PLS) regression. Relationships between diatoms and mean July air temperature were independent of lake-water pH, TOC, alkalinity and maximum depth. The results demonstrated that diatoms in lake sediments can provide useful and independent quantitative information for estimating past changes in mean July air temperature (R2 jack = 0.62, RMSEP = 0.86 °C; R2 and root mean squared error of prediction (RMSEP) based on jack-knifing), pH (R2 jack = 0.61, RMSEP = 0.30) and TOC (R2 jack = 0.49, RMSEP = 1.33 mg l-1). The paper focuses mainly on the relationship between diatom community composition and mean July air temperature, but the relationships to pH and TOC are also discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008128014721
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  • 16
    Electronic Resource
    Electronic Resource
    Effect of host density, temperature, and photoperiod on the fitness of Anagyrus kamali, a parasitoid of the hibiscus mealybug Maconellicoccus hirsutus (2000)
    Springer
    Entomologia experimentalis et applicata 96 (2000), S. 141-147 
    Details
    ISSN: 1570-7458
    Keywords: Anagyrus kamali ; Encyrtidae ; parasitoid ; Maconellicoccus hirsutus ; Pseudococcidae ; host density ; functional response ; temperature ; photoperiod
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The peformance of the parasitoid Anagyrus kamali Moursi [Hymenoptera: Encyrtidae], as a function of host density, temperature, and photoperiod was investigated with the objective to optimize a mass-rearing system in the context of a biological control program. The number of hosts parasitized at densities varying from 2–100 hibiscus mealybug (HMB), Maconellicoccus hirsutus Green [Homoptera: Pseudococcidae], corresponded to a type II-III functional response in fixed-time conditions and a type III in variable-time conditions. Twenty-six percent of the oviposited eggs led to progeny emergence with a sex ratio of 0.49±0.102 (M/F), regardless of host density. Fecundity and oviposition period under six abiotic combinations (i.e., two temperatures (26±2 °C and 32±2 °C) and three photoperiods (L0:D24, L12:D12, L24:D0)) were measured. Lifetime fecundity and reproductive life were significantly affected by temperature and photoperiod conditions. Optimum female parasitoid lifetime fecundity was attained at 26±2 °C, L0:D24 with an average of 116.1±17.43 eggs. At 32±2 °C, L24:D0 and L12:D12, an average of 79.4±34.57 and 85.8±35.81 eggs were laid, respectively. Reproductive longevity was maximal at 26±2 °C, L0:D24 with 12±4.85 days of oviposition. Because the parasite A. kamali can be reared optimally without light, this may save tremendous energy costs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004021800991
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  • 17
    Electronic Resource
    Electronic Resource
    The temperature-dependent duration of development and parasitism of three cereal aphid parasitoids, Aphidius ervi, A. rhopalosiphi, and Praon volucre (2000)
    Springer
    Entomologia experimentalis et applicata 95 (2000), S. 173-184 
    Details
    ISSN: 1570-7458
    Keywords: Aphidius ervi ; Aphidius rhopalosiphi ; Praon volucre ; Sitobion avenae ; temperature ; development time ; parasitization ; superparasitization ; lower temperature thresholds ; immature mortality ; sex ratio
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Temperature dependencies were established for the egg-to-mummy and mummy-to-adult phases, for mummy mortality, and for parasitism of Aphidius ervi Haliday, Aphidius rhopalosiphi De Stefani-Perez, and Praon volucre (Haliday) (Hymenoptera, Aphidiidae), three parasitoids of Sitobion avenae (Fabricius) (Homoptera, Aphididae), at 8 °C, 12 °C, 16 °C, 20 °C, and 25 °C on winter wheat (cv. Haven). A physiological model described temperature-dependent development over the full temperature range, whereas a linear model was fitted for data above 8 °C and used to estimate the lower temperature thresholds and day-degrees (° D) required for development. The thresholds for A. ervi were 2.2 °C for egg-mummy development and 6.6 °C for mummy-adult development, those for A. rhopalosiphi were 4.5 °C and 7.2 °C, and those for P. volucre were 3.8 °C and 5.5 °C. The time to develop into mummies and adults differed significantly between the three species: A. ervi development into mummies required an average of 159 ° D, while development into adults took an average of 73 ° D. The corresponding average times required for A. rhopalosiphi and P. volucre to develop mummies were 124° D and 126° D, while their development into adults required an average of 70° D and 150° D, respectively. Mummy mortality was 25–35% at 8 °C and less at the higher temperatures tested, but began to increase again at 25 °C, showing a quadratic relationship between mortality and temperature. Parasitization was very low or, in the case of P. volucre, absent up to 12 °C and thereafter increased with increasing temperature. The relationship between parasitization, recorded as percent aphids mummified, and temperature was linear at the temperatures tested and depended on species. A. ervisuperparasitized 11.1% aphids at 20 °C and 16.6% aphids at 25 °C, whereas superparasitism was low in A. rhopalosiphi and absent in P. volucre. From 16 °C to 25 °C the P. volucre sex ratio increased. For A. ervi and A. rhopalosiphi there was no trend with temperature, but at 20 °C and 25 °C it was close to even. Field data for 1996 and 1997 allowed for a comparison of actual and expected emergence of overwintering mummies. In both years, parasitoids were predicted to have emerged from overwintering mummies well in advance of the onset of aphid infestation, and more than a month earlier than the first parasitized aphids were found in winter wheat. Observations from trap plants in other crops supported the predictions of the models. Other factors that can affect biological control by cereal aphid parasitoids are discussed.
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    URL: http://dx.doi.org/10.1023/A:1003993719952
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    Studies on the Complexation Behavior of Thorium(IV). 1. Hydrolysis Equilibria (2000)
    Springer
    Journal of solution chemistry 29 (2000), S. 63-86 
    Details
    ISSN: 1572-8927
    Keywords: Thorium ; hydrolysis ; potentiometry ; solvent extraction ; temperature ; thermodynamics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The stability constants of thorium(IV) hydrolysis species have been measured at15, 25, and 35°C (in 1.0 mol dm−3 NaClO4) using both potentiometry and solventextraction. The results indicate the presence of the monomeric speciesTh(OH)3+, Th(OH)2+ 2, Th(OH)+ 3, and Th(OH)4, in addition to the polymericspecies Th4(OH)8+ 8 and Th6(OH)9+ 15. The polymeric species were found to beimportant, although the total thorium concentration was limited to 0.01–0.1mmol-dm−3. The solvent extraction measurements required the use of acetylacetone.As such, the stability constants of thorium(IV) with acetylacetone were alsomeasured using both potentiometry and solvent extraction. All logarithms of thestability constants were found to be linear functions of the reciprocal absolutetemperature indicating that ΔH o and ΔSo of reaction are both independent oftemperature (over the temperature range examined in the study).
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    URL: http://dx.doi.org/10.1023/A:1005166517699
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    Conductivity of Dilute Aqueous Electrolyte Solutions at High Temperatures and Pressures Using a Flow Cell (2000)
    Springer
    Journal of solution chemistry 29 (2000), S. 217-235 
    Details
    ISSN: 1572-8927
    Keywords: Flow-through cell ; conductivity ; electrolyte ; ion association ; temperature ; pressure ; LiCl ; NaCl ; KCl
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A flow-through electrical conductance cell was assembled in order to measuremolar conductances of dilute aqueous electrolytes with a high degree of accuracyat high temperatures and pressures. The design of the cell is based on the conceptdeveloped at the University of Delaware and built in 1995, with modificationsthat will allow the cell to operate at much higher temperatures (to 600°C) andpressures (to 300 MPa). At present, the cell has been tested successfully bymeasuring aqueous (10−4-10−3 mol-kg−1) solutions of LiCl, NaCl, and KCl attemperatures 25–410°C and pressures 9.8–33 MPa. The results are in goodagreement with reported values, including those measured with the Delawareflow-through cell. These new results are also complementary to our previousresults, which were measured with a static high-pressure cell. Measurements attemperatures near the critical point of water (374°C, 22.1 MPa) require the useof lower solution concentrations that were unachievable in the past with thestatic cell.
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    URL: http://dx.doi.org/10.1023/A:1005146332605
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    Nutrient fluxes in intertidal communities of a South European lagoon (Ria Formosa) – similarities and differences with a northern Wadden Sea bay (Sylt-Rømø Bay) (2000)
    Springer
    Hydrobiologia 436 (2000), S. 217-235 
    Details
    ISSN: 1573-5117
    Keywords: nutrient flux ; nitrogen ; phosphate ; tidal flats ; temperature ; geographical comparison
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract During an annual cycle, flux rates of oxygen, nitrate, nitrite, ammonium, phosphate and silicate were measured in light and dark bell jars at three sites in Ria Formosa (Algarve, Portugal) enclosing either a natural macrophytic community (macroalgae on sand or mud, a seagrass bed of Zostera noltii) or bare sediments. The results are compared with a preceeding study in which the same bell jar technique has been applied in the Sylt-Rømø Bay of the northern Wadden Sea. Nitrate flux was mainly directed from the water column to the benthic communities in Ria Formosa, as well as in the Sylt-Rømø Bay. However, nitrate uptake was higher in the northern, more eutrophic study area. In Ria Formosa, nutrient concentrations were lower than in the Sylt-Rømø Bay possibly due to strong water exchange with Atlantic waters. High temperatures and strong insolation had a greater impact on nitrate fluxes in Ria Formosa than in the Sylt-Rømø Bay. Bioturbating macrofauna increased ammonium efflux in the Sylt- Rømø Bay while this effect was not as pronounced in the Ria Formosa study sites. Benthic phosphate uptake dominated in the Ria Formosa and was correlated to initial phosphate concentrations in incoming waters. At both study sites, oxygen and nutrient fluxes were correlated with temperature. Additionally, flux rates were strongly influenced by biotic components and levels of eutrophication. A literature survey showed that mainly in temperate regions, material fluxes increase with temperature, whereas in warmer areas, ammonium and phosphate fluxes between sediment and water were generally lower.
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    URL: http://dx.doi.org/10.1023/A:1026542621512
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    Reproduction of the Endangered Killifish Aphanius iberus at Different Salinities (2000)
    Springer
    Environmental biology of fishes 57 (2000), S. 113-115 
    Details
    ISSN: 1573-5133
    Keywords: photoperiod ; temperature ; spawning ; larva rearing ; larva food
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Adult fish of a freshwater population of the Iberian endangered cyprinodontid Aphanius iberus, were induced to reproduce at salinities of 5, 15, 30, 45 and 60 ppt. For each salinity five 30 l aquaria were used, each one including a male and two females. Maturity and spawning outside the natural season, were obtained at conditions of 22 to 28°C and a photoperiod of 14L:10D. The larvae were fed with rotifers Brachionus plicatilis and Synchaeta cecilia valentina. Experiment lasted 40 days. The first spawning occurred on the 17th day at 45 ppt of salinity and the first embryos hatched on the 34th day at 5 and 15 ppt salinity. The final average number of larvae per aquarium ranged from 5.2 (45 ppt salinity) to 10.8 (15 ppt salinity). No significant differences were found between the average values at different salinities (p〈0.01).
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    URL: http://dx.doi.org/10.1023/A:1007579527064
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    Energy exploitation in Chirocephalus croaticus (Steuer, 1899) (Crustacea: Anostraca): survival strategy in an intermittent lake (2000)
    Springer
    Hydrobiologia 437 (2000), S. 157-163 
    Details
    ISSN: 1573-5117
    Keywords: Chirocephalus ; metabolic potential ; intermittent lake ; ecology ; physiology ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Electron transport system (ETS) activity was measured in Chirocephalus croaticus from the intermittent lake, Petelinjsko Jezero. The ETS activities were measured at 5, 10, 15, 20, and 25 °C, and were studied separately in juveniles, females and males. Juveniles had significantly higher activity than adults at a standard temperature of 20 °C. The mass-specific ETS activity decreased with increasing size of the animals; the value b was 0.787. Respiration rates (R) were determined at 20 °C and the ratio ETS/R (±standard deviation) for C. croaticus was 1.43±0.46 (n=38). ETS activity increased with temperature. Females had higher Q10 than males in higher temperature range (t-test; t=2.50; d.f.=8; p〈0.05). Activation energy Ea was higher for females than males (t-test; t=2.35; d.f.=8; p〈0.05). Females exhibited lower ETS activity than males over the lower temperature range, but their ETS could function more efficient at higher temperature.
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    URL: http://dx.doi.org/10.1023/A:1026507024238
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    Effects of urban runoff from a detention pond on water quality, temperature and caged Gammarus minus (Say) (Amphipoda) in a headwater stream (2000)
    Springer
    Hydrobiologia 441 (2000), S. 107-116 
    Details
    ISSN: 1573-5117
    Keywords: urban runoff ; in situ bioassay ; Gammarus minus ; heavy metals ; water quality ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Thompson Run, a headwater stream in central Pennsylvania (U.S.A.), supports an impaired macroinvertebrate community downstream of the outlet of a detention pond that receives urban runoff. To determine if toxicity from the metals or other pollutants in urban runoff contributed to impairment, we exposed adult, male Gammarus minus to urban runoff during a 42-day in situ bioassay that included 12 rain events. Test animals were collected from a site upstream of the detention pond outlet using two methods: precopula pair separation and sieving. Water quality, temperature and tissue metal concentrations were measured during the bioassay. The survival of precopula G. minus was lower (p=0.048) at a site downstream of the detention pond outlet compared to a site upstream of it, but the survival of sieved G. minus was not different between sites (p=0.803). Large hourly increases in temperature (up to 6.6 °C) and major reductions in water quality including order of magnitude increases in suspended materials (measured as turbidity) and the concentrations of copper, zinc and lead occurred downstream of the detention pond outlet during stormflow (i.e. following rain events). In contrast, changes in temperature and water quality were minor upstream of the pond outlet throughout the bioassay. Copper and cadmium concentrations in leaf samples and copper, zinc and lead concentrations in G. minus samples were significantly higher downstream of the pond outlet than they were upstream of it. Despite harsh conditions downstream of the pond outlet (i.e. metal contamination, inputs of suspended materials and rapid temperature increases), the in situ bioassay did not convincingly demonstrate that urban runoff was toxic to adult, male G. minus.
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    URL: http://dx.doi.org/10.1023/A:1017550321076
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    Seasonal and Diel Changes in Behaviour, Microhabitat use and Preferences by Young Pool-dwelling Atlantic Salmon, Salmo salar, and Brown Trout, Salmo trutta (2000)
    Springer
    Environmental biology of fishes 59 (2000), S. 163-179 
    Details
    ISSN: 1573-5133
    Keywords: deep pools ; young salmonids ; habitat use ; habitat availability ; temporal variation ; temperature ; winter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract There was a pronounced decline in activity of young pool-dwelling Atlantic salmon, Salmo salar, and brown trout, Salmo trutta, as the water temperatures dropped in the autumn and early winter, and the fish switched from a predominantly diurnal towards a nocturnal activity pattern. Such a switch in activity pattern has previously been observed in young brown trout, but the present study is the first documentation for juvenile Atlantic salmon under natural conditions. Juvenile fish fed actively even when water temperatures were below 0°C, although foraging behaviour at near-freezing temperatures was recorded exclusively during night surveys. This indicates that other proximate factors, in addition to water temperature, affect the activity of young salmon and trout in rivers. Trout kept feeding positions significantly higher above bottom than salmon in August and September, but both species reduced the height above bottom at the onset of winter, possibly due to reduced swimming performance and lowered food availability in the upper part of the water column.
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    URL: http://dx.doi.org/10.1023/A:1007691316864
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    Will changes in soil organic carbon act as a positive or negative feedback on global warming? (2000)
    Springer
    Biogeochemistry 48 (2000), S. 21-51 
    Details
    ISSN: 1573-515X
    Keywords: carbon cycle ; decomposition ; global change ; soil organic matter ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract The world's soils contain about 1500 Gt of organic carbon to a depth of 1m and a further 900 Gt from 1--2m. A change of total soil organic carbon by just 10% would thus be equivalent to all the anthropogenic CO2 emitted over 30 years. Warming is likely to increase both the rate of decomposition and net primary production (NPP), with a fraction of NPP forming new organic carbon. Evidence from various sources can be used to assess whether NPP or the rate of decomposition has the greater temperature sensitivity, and, hence, whether warming is likely to lead to an increase or decrease in soil organic carbon. Evidence is reviewed from laboratory-based incubations, field measurements of organic carbon storage, carbon isotope ratios and soil respiration with either naturally varying temperatures or after experimentally increasing soil temperatures. Estimates of terrestrial carbon stored at the Last Glacial Maximum are also reviewed. The review concludes that the temperature dependence of organic matter decomposition can be best described as: d(T) = exp[3.36 (T − 40)/(T + 31.79)] where d(T) is the normalised decomposition rate at temperature T (in °C). In this equation, decomposition rate is normalised to ‘1’ at 40 °C. The review concludes by simulating the likely changes in soil organic carbon with warming. In summary, it appears likely that warming will have the effect of reducing soil organic carbon by stimulating decomposition rates more than NPP. However, increasing CO2 is likely to simultaneously have the effect of increasing soil organic carbon through increases in NPP. Any changes are also likely to be very slow. The net effect of changes in soil organic carbon on atmospheric CO2 loading over the next decades to centuries is, therefore, likely to be small.
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    URL: http://dx.doi.org/10.1023/A:1006238902976
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    A drop in ambient temperature results in a transient reduction of interrenal ACTH responsiveness in the gilthead sea bream (Sparus aurata, L.) (2000)
    Springer
    Fish physiology and biochemistry 23 (2000), S. 265-273 
    Details
    ISSN: 1573-5168
    Keywords: cortisol ; ACTH ; α-MSH ; GH ; head kidney ; pituitary ; temperature ; stress ; Sparus aurata
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This study investigated the effects of a drop in water temperature (18 °C to 9 °C in 24 h) on the pituitary and interrenal hormones of the gilthead sea bream Sparus aurata. The in vitro sensitivity of the interrenal tissue to ACTH, plasma levels of cortisol, ACTH, α-MSH, GH, glucose, lactate and ions were determined. In vitro ACTH, stimulated the release of cortisol from isolated interrenal glands from control gilthead sea bream in a concentration dependent fashion. However, the interrenal cells were less sensitive to ACTH as soon as 24 h following the onset of the temperature drop. At this time, plasma cortisol and ACTH levels were raised, and plasma GH concentrations were decreased, whereas no significant changes were found in plasma α-MSH. After 96 h plasma ACTH levels had recovered whereas plasma cortisol levels were still higher than controls after 8 days of the beginning of the experiment. Interrenal sensitivity had recovered after 8 days. The results may help to clarify the relationship between the stress response and the aetiology of the winter syndrome in sea bream.
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    URL: http://dx.doi.org/10.1023/A:1007873811975
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    The physiological response of Northern krill (Meganyctiphanes norvegica) to temperature gradients in the Kattegat (2000)
    Springer
    Hydrobiologia 426 (2000), S. 157-160 
    Details
    ISSN: 1573-5117
    Keywords: Meganyctiphanes norvegica ; respiration ; temperature ; vertical migration ; Kattegat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The Alkor-Deep (140 m), which forms part of a depression system in the northern Kattegat channel east of the island of Læsø (Denmark), is the location of a self sustaining population of Northern krill, Meganyctiphanes norvegica (Euphausiacea). This population is exposed to one of the most pronounced thermal gradients within the distributional range of this pelagic crustacean. During summer, the temperature of the water column ranges between 4 and 6 in the deep to 16 °C near the surface which results in the krill being exposed to temperature differences of 8–10 °C during diel vertical migration. Oxygen consumption rates were used to investigate the physiological adaptation of the animal to such gradients in temperature. The rates were found to increase exponentially from 31 μmol O2 h-1 gdw -1 at 4 °C to 72 μmol O2 h-1 gdw -1 at 16 °C, giving a Q 10-value of 2.0, and indicating that physiological adaptation to varying thermal conditions does not take place. Behavioural adaptations are discussed which may help the krill to cope with large temperature gradients in their environment.
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    URL: http://dx.doi.org/10.1023/A:1003974613473
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    The influence of climate change scenarios on populations of the mayfly Cloeon dipterum (2000)
    Springer
    Hydrobiologia 441 (2000), S. 55-62 
    Details
    ISSN: 1573-5117
    Keywords: climate change ; temperature ; mayflies ; Cloeon dipterum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Populations of the mayfly Cloeon dipterum from 48 ponds (3000 l fibre-glass tanks of 1 m depth) were monitored over the course of 1 year. To simulate possible patterns of climatic change, the ponds were subject to three temperature treatments: continuous heating to 3 °C above ambient; heating to 3 °C above ambient during the summer only; and no heating. Further experimental complexity included enhanced nutrient input into the ponds and the presence or absence of fish, giving a factorial combination of 3 temperature regimes × 2 nutrient levels × presence/absence of fish predation. Few nymphs were found in the presence of fish. Where fish were absent, the temperature treatments did not significantly affect nymph abundances, and only marginally influenced mean nymph body-lengths. In contrast, the nutrient treatment had significant effects on both nymph abundance and size, with greater numbers of generally larger nymphs occurring in those fish-free ponds receiving additional nutrients. Adult emergence began earlier in the year from the heated ponds, particularly those ponds receiving additional nutrients. Adult body-length differed between temperature treatments, but consistent patterns were difficult to ascertain because of interactions with nutrient treatment and seasonal effects. Our results show that during the short term at least, elevated temperature as a simulation of climate change does not have an overwhelming influence on either mayfly abundance or size. The influence of temperature is subtle and subject to complex interaction with other habitat variables. We therefore suggest that the direct consequences of small changes in temperature will likely be of little significance to C. dipterum, relative to indirect effects operating through interactions with predation and nutrient input.
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    URL: http://dx.doi.org/10.1023/A:1017595223819
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    Further expansion of the genus Cercopagis (Crustacea, Branchiopoda, Onychopoda) in the Baltic Sea, with notes on the taxa present and their ecology (2000)
    Springer
    Hydrobiologia 429 (2000), S. 207-218 
    Details
    ISSN: 1573-5117
    Keywords: Cercopagis ; invasion ; Baltic Sea ; depth ; temperature ; salinity ; morphological variations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The onychopod cladoceran Cercopagis that recently invaded the Baltic Sea is reported from new zones of the northern Baltic proper. Because of successful survival and an expanding distribution range, the addition of Cercopagis to the Baltic fauna is considered to be permanent. What has previously been cited as Cercopagis pengoi encompasses the morphology of several other species, subspecies and forms. Either a number of morphologically similar species is present, or there is a number of spurious species in Cercopagis. The last hypothesis is favoured. The spatial distribution pattern of Cercopagis, as well as that of total zooplankton, was correlated with depth. Deep (〉100 m) and shallow (〈10 m) stations had significantly lower abundance than stations of intermediate depth (〈100 m). An overview of the distribution of C. pengoi group in fresh and brackish waters suggests a high tolerance to environmental factors, but with differences among taxa. Due to this ecological flexibility, the colonization of the Baltic is not unexpected. Increasing salinity may restrict dispersal of cercopagids to the southern areas of the Baltic and to the North Sea, but inland lakes (e.g. in Sweden) present an ecological profile suitable for colonization.
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    URL: http://dx.doi.org/10.1023/A:1004004504571
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    Changes in Na+,K+-ATPase activity and gill chloride cell morphology in the grouper Epinephelus coioides larvae and juveniles in response to salinity and temperature (2000)
    Springer
    Fish physiology and biochemistry 23 (2000), S. 83-94 
    Details
    ISSN: 1573-5168
    Keywords: chloride cells ; Epinephelus coioides ; grouper ; Na+,K+-ATPase activity ; salinity ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The activity of the enzyme Na+,K+-ATPase and morphological changes of gill chloride cells in grouper, Epinephelus coioides larvae and juveniles were determined 6–48 h after abrupt transfer from ambient rearing conditions (30–32 ppt, 26.5–30 °C) to different salinity (8, 18, 32, 40 ppt) and temperature (25, 30 °C) combinations. Na+,K+-ATPase activity in day 20 larvae did not change at salinities 8–32 ppt. Activity decreased significantly (P 〈0.01) after exposure to 40 ppt at 25–30 °C, which was accompanied by an increase (P 〈0.05) in density and fractional area of chloride cells. Enzyme activity in 40 ppt did not reach a stable level and larvae failed to recover from an osmotic imbalance that produced a low survival at 25 °C and death of all larvae at 30 °C. Enzyme activity and chloride cell morphology in day 40 groupers did not change in 8–40 ppt at 25 °C and 8–32 ppt at 30 °C. A significant decrease and a subsequent increase in Na+,K+-ATPase activity in 40 ppt at 30 °C was associated with the increase in chloride cell density resulting in an increased fractional area but a decreased cell size. Enzyme activity and chloride cells of day 60 grouper were unaffected by abrupt transfer to test salinities and temperatures. These results demonstrate that grouper larvae and juveniles are efficient osmoregulators over a wide range of salinities. Salinity adaptation showed an ontogenetic shift as the larvae grew and reached the juvenile stage. This development of tolerance limits may reflect their response to actual conditions existing in the natural environment.
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    URL: http://dx.doi.org/10.1023/A:1007827331137
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    Environmental influences on melatonin secretion in Atlantic cod (Gadus morhua L.) and their relevance to commercial culture (2000)
    Springer
    Fish physiology and biochemistry 23 (2000), S. 191-200 
    Details
    ISSN: 1573-5168
    Keywords: Atlantic cod ; temperature ; melatonin ; photoperiod
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This study investigated the effects of photoperiod and temperature on plasma melatonin secretion in Atlantic cod (Gadus morhua L.). Initial work confirmed the presence of a diel profile of melatonin synthesis, with elevated levels during the dark phase. Unusually for fish, the peak in plasma melatonin occurred towards the end of the dark phase, which is indicative of a type `A' melatonin profile. When exposed to 60 hours of continuous darkness a clear endogenous rhythm of melatonin synthesis was observed, which continued for 4 cycles with a periodicity which, approximated to 24 h. When acclimated to varying temperatures (4, 8, 12 or 16 °C) no variation in melatonin production was seen, however, body size appeared to be an important influence, with the smallest fish exhibiting significantly higher levels of dark phase melatonin. Finally, the application of additional night-time illumination to cod maintained in sea cages i.e. without blackout, did not significantly reduce dark phase plasma melatonin, suggesting that cod are less sensitive to photoperiod manipulation in cages than salmonids.
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    URL: http://dx.doi.org/10.1023/A:1007816426509
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    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.
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    URL: http://dx.doi.org/10.1023/A:1006624907975
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    Geographical Clines for Quantitative Traits in Natural Populations of a Tropical Drosophilid: Zaprionus Indianus (2000)
    Springer
    Genetica 108 (2000), S. 91-100 
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    ISSN: 1573-6857
    Keywords: altitude ; clines ; latitude ; phenotypic variability ; temperature ; Zaprionus indianus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We analyzed natural populations of Zaprionus indianusin 10 Indian localities along a south-north transect (latitude: 10–31°3 N). Size traits (body weight, wing length and thorax length) as well as a reproductive trait (ovariole number) followed a pattern of clinal variation, that is, trait value increased with latitude. Wing/thorax ratio, which is inversely related to wing loading, also had a positive, but non-significant correlation with latitude. By contrast, bristle numbers (sternopleural and abdominal) exhibited a non-significant but negative correlation with latitude. Sex dimorphism, estimated as the female/male ratio, was very low in Z. indianus, contrasting with results already published in other species. Genetic variations among populations were also analyzed according to other geographic parameters (altitude and longitude) and to climatic conditions from each locality. A significant effect of altitude was found for size traits. For abdominal bristles, a multiple regression technique evidenced a significant effect of both latitude and altitude, but in opposite directions. Genetic variations were also correlated to climate, and mainly with average year temperature. Taking seasonal variations into account failed however to improve the predictability of morphometrical variations. The geographic differentiation of Z.indianusfor quantitative traits suggests adaptive response to local conditions, especially to temperature, but also reveals a complex situation according to traits investigated and to environmental parameters, which does not match results on other drosophilid species.
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    URL: http://dx.doi.org/10.1023/A:1004090517967
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    Can zebra mussels change stratification patterns in a small reservoir? (2000)
    Springer
    Hydrobiologia 431 (2000), S. 175-184 
    Details
    ISSN: 1573-5117
    Keywords: Dreissena ; lake stratification ; water clarity ; temperature ; oxygen ; metalimnion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Colonization and proliferation of zebra mussel (Dreissena polymorpha) population in Hargus lake, a small thermally stratified reservoir in Ohio, U.S.A., caused a significant increase in water clarity and a remarkable decrease in phytoplankton biomass during the period from 1993 to 1995. Increased light penetration and reduced organic matter loading to the meta-and hypolimnion were reflected in the lake stratification patterns, particularly in the temperature and oxygen profiles in the metalimnion. The meta- and hypolimnetic water temperature increased significantly over three years, irrespective of variation in surface water temperature. The epilimnion depth (mixing depth) increased by about the same magnitude as did the average Secchi depth. However, the total heat content of the lake did not show a consistent trend to increasing zebra mussel abundance, as it was largely influenced by the temperature of the large water volumes near the surface, which were in turn affected by weather conditions. Concurrent with the thermal structure change, the dissolved oxygen structure also changed over three years, though to a lesser extent. The changes in oxygen stratification pattern were reflected by increased oxygen concentrations in the metalimnion and a lowered depth of 3 mg l−1 DO isopleth. These observed changes were likely attributed to increased water mixing depth, metalimnion photosynthesis and reduced oxygen consumption by organic matter. With increased epilimnion thickness and improved oxygen conditions in the metalimnion, the habitable space for aquatic macro-organisms (including fish) expanded substantially. Our results suggest that the indirect impacts of zebra mussels on small lake stratification patterns may have much broader implications than do the direct trophic interactions to the whole ecosystem.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004092229180
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    Survival and plant-prey finding by Neoseiulus fallacis Neoseiulus fallacis (Acari: Phytoseiidae) on soil substrates after aerial dispersal (2000)
    Springer
    Experimental and applied acarology 24 (2000), S. 579-596 
    Details
    ISSN: 1572-9702
    Keywords: Tetranychus urticae ; ambulatory dispersal ; temperature ; humidity ; mortality ; emigration ; immigration ; biological control
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In a greenhouse and in an open field, aspects of aerial and ambulatory dispersal of the phytoseiid mite, Neoseiulus fallacis (Garman) were studied with a focus on events that would occur after aerially dispersing mites had landed on soil or associated substrates. We measured recovery of predators on lima bean plants (Phaseolus lunatus L.) that were infested with the two-spotted spider mite, Tetranychus urticae Koch. Factors thought to affect movement and colonization were distance to a receiver unit from a release (landing) point, intervening soil surfaces such as clods, gravel, fine soil and grass, and management of soil surfaces such as mulching, watering or both. In the field, the effect of distance (0.11–1.76 m) from a landing point to a receiver unit was significant, with a negative log-linear relationship. Soil surfaces such as clods and management actions such as watering with mulching allowed for more capture of predators on bean plants with prey than did other treatments. Environmental conditions greatly affected survival of N. fallacis.Predators in the field that were present on bare soil suffered high mortality (ca. 90%) at fluctuating daytime conditions of 26.4 ± 4.8°C and 56 ± 13.4% RH. Predators only suffered 10% mortality in the greenhouse under the same setting, but under more controlled and favorable environmental conditions. Effects of environmental conditions, mode of dispersal and implications to biological control are discussed.
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    URL: http://dx.doi.org/10.1023/A:1026593907917
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    Differences in the Denaturation Behavior of Ribonuclease A Induced by Temperature and Guanidine Hydrochloride (2000)
    Springer
    The protein journal 19 (2000), S. 345-352 
    Details
    ISSN: 1573-4943
    Keywords: Ribonuclease A ; limited proteolysis ; temperature ; guanidine hydrochloride ; unfolding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Moderate temperatures or low concentrations of denaturants diminish the catalytic activity of some enzymes before spectroscopic methods indicate protein unfolding. To discriminate between possible reasons for the inactivation of ribonuclease A, we investigated the influence of temperature and guanidine hydrochloride on its proteolytic susceptibility to proteinase K by determining the proteolytic rate constants and fragment patterns. The results were related to changes of activity and spectroscopic properties of ribonuclease A. With thermal denaturation, the changes in activity and in the rate constants of proteolytic degradation coincide and occur slightly before the spectroscopically observable transition. In the case of guanidine hydrochloride-induced denaturation, however, proteolytic resistance of ribonuclease A initially increases accompanied by a drastic activity decrease far before unfolding of the protein is detected by spectroscopy or proteolysis. In addition to ionic effects, a tightening of the protein structure at low guanidine hydrochloride concentrations is suggested to be responsible for ribonuclease A inactivation.
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    URL: http://dx.doi.org/10.1023/A:1026479212350
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    Quantitative analysis of cell division in leaves: methods, developmental patterns and effects of environmental conditions (2000)
    Springer
    Plant molecular biology 43 (2000), S. 555-567 
    Details
    ISSN: 1573-5028
    Keywords: cell cycle ; kinematic analysis ; leaf development ; light ; temperature ; water deficit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In planta quantitative studies of cell cycle are necessary for examining the role of cell division in the response of plants to environmental conditions and to analyse the behaviour of transformed plants in this context. We present and discuss non-intrusive kinematic methods which allow estimating the duration of cell cycle with a high spatial resolution in the leaf. Different methods are proposed and discussed for monocotyledons and dicotyledons, and compared with methods involving the use of chemicals. In monocotyledon leaves, cell division is restricted to a limited zone near the leaf insertion point, twice as long in the mesophyll as in the epidermis. In dicotyledons, cell division occurs in the whole leaf with a uniform and constant cell cycle duration for a determinate number of cell cycles, representing about half of leaf development. Over several experiments, this number is well conserved in a given leaf zone in the absence of stresses, but larger near the leaf base than near the leaf tip. After that, cell cycle duration increases because cells are progressively blocked in G1 while the durations of S-G2-M phases do not change with time. Leaf temperature affects neither the distribution of nuclei in each phase of the cycle nor the number of cell cycles in a leaf. Water or light deficits both cause a partial blockage of nuclei in G1 during the stress only, thereby increasing cell cycle duration and decreasing final cell number. These results suggest that a strong developmental programme drives cell division in leaves, so a simple framework allows analysis of temporal patterns, of spatial gradients and of the effect of environmental conditions.
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    URL: http://dx.doi.org/10.1023/A:1006438321386
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    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.
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    URL: http://dx.doi.org/10.1023/A:1026528830228
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    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.
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    URL: http://dx.doi.org/10.1023/A:1004838218642
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    Effects of Smoke Emissions from a Charcoal Kiln on the Functioning of Forest Soil Systems: A Microcosm Study (2000)
    Springer
    Environmental monitoring and assessment 60 (2000), S. 337-357 
    Details
    ISSN: 1573-2959
    Keywords: cellulose ; charcoal kiln ; decomposition ; herb seeds ; moisture ; respiration ; smoke pollution ; soil ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Long-term charcoal production in small private charcoal kilns (CK) in Eastern Bieszczady Mts. (SE Poland) can cause local smoke contamination of the ambient forest environment. Responses of model soil systems, contaminated or not contaminated by CK smoke, to contrasting combinations of hydrothermic regimes were compared in laboratory microcosms (respiration of soil community, decomposition rate of soil organic matter and cotton stripes, herb seeds germination were studied). The majority of the obtained data show a markedly higher level of soil biological activity in the CK versus the control series. In some cases CK and control soil systems show different patterns of reactions to the tested combinations of microclimate regime. These phenomena should at least partly be attributed to the effects of CK pollution.
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    URL: http://dx.doi.org/10.1023/A:1006115104675
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    Effects of Temperature and Photoperiod on Phytotoxic Root Exudates of Cucumber (Cucumis sativus) in Hydroponic Culture (2000)
    Springer
    Journal of chemical ecology 26 (2000), S. 1953-1967 
    Details
    ISSN: 1573-1561
    Keywords: Allelopathy ; autotoxicity ; activated charcoal ; cucumber ; Cucumis sativus L ; 2,4-dichlorobenzoic acid ; organic acids ; photoperiod ; temperature ; root exudates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract In order to elucidate the effects of temperature and photoperiod on the quality and quantity of plant root exudates, a Japanese cucumber (Cucumis sativus, cv. Shougoin-Aonaga-Fushinari) was grown hydroponically in growth chambers under controlled temperature and photoperiod conditions with or without the addition of activated charcoal (AC) to the nutrient solutions. Fresh AC was used to trap the organic compounds exuded from cucumber roots every two weeks. Cucumber plants without AC were severely retarded in root growth and in the accumulation of dry matter, especially at high temperature and long photoperiod, compared to those with AC. The growth inhibitors, adsorbed on the AC or accumulated in the nutrient solution without AC, were extracted by organic solvents and analyzed by GC-MS. Benzoic acid and its derivatives, cinnamic acid derivatives, and fatty acids were identified. The rate of root exudation in vegetative and reproductive stages for some of these organic acids increased with the elevation of temperature and the elongation of photoperiod, and the mean rate was two or more times higher than the minimum exudation at low temperature with short photoperiod. Some of the identified compounds significantly inhibited the germination and/or root growth of lettuce and cucumber.
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    URL: http://dx.doi.org/10.1023/A:1005509110317
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    Effect of the Environment on the Bacterial Bleaching of Corals (2000)
    Springer
    Water, air & soil pollution 123 (2000), S. 337-352 
    Details
    ISSN: 1573-2932
    Keywords: bleaching ; bacterial infection ; coral ; Oculina ; temperature ; toxin ; zooxanthellae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Bleaching in stony-corals is the result of disruption of symbiosis between the coral hosts and photosynthetic microalgal endosymbionts (zooxanthellae). Coral bleaching events of unprecedented frequency and global extent have been reported during the last two decades. Recently, we demonstrated that bleaching of the coral Oculina patagonica in the Mediterranean Sea is caused by the bacterium Vibrio shiloi, when seawater temperature rises and allows the bacterium to become virulent. The first step in the infection process is host-specific adhesion of V. shiloi to O. patagonica via a β-galactoside receptor on the coral surface. The bacterium then penetrates into the coral tissue and produces extracellular materials which rapidly inhibit photosynthesis of zooxanthellae and bleach and lyse the algae. The inhibition of pothosynthesis is due to a low molecular weight, heat stable toxin and ammonia. Bleaching and lysis are due to a heat-labile, high molecular weight materials, probably lytic enzymes. Elevated temperature induces different virulence factors within the infectious agent of the disease, V. shiloi. Adhesion was found to be temperature-regulated. When the bacteria were grown at 16°C there was no adhesion to corals maintained at either 25°C or 16°. However, when the bacteria were grown at 25°C they adhered avidly to corals maintained at 16°C and 25°C. In addition, the production of lytic enzymes and the photosynthesis inhibitor was also found to be temperature dependent. Production of the latter toxin was ten times greater at 29°C than at 16°C, and extracellular protease was 5-fold higher in cultures grown at 29°C than at 16°C. The data presented here suggest an explanation for the correlation between elevated seawater temperatures and seasonal coral bleaching.
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    URL: http://dx.doi.org/10.1023/A:1005274331988
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    On the Influence of Hot-Water Discharges on Phytoplankton Communities from a Coastal Zone of the Gulf of Mexico (2000)
    Springer
    Water, air & soil pollution 119 (2000), S. 209-230 
    Details
    ISSN: 1573-2932
    Keywords: microalgal communities ; photosynthesis ; temperature ; thermal pollution ; tropical coast
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The influence of thermal discharges on thephytoplankton community from a coastal zone of theGulf of Mexico was evaluated through their structureand photosynthetic behaviour focusing on responses tochanges in light and temperature. Biological andphysicochemical parameters were measured over a periodof two years in an area with permanent hot waterdischarges from a thermoelectric plant. Thetemperature in the sampling area ranged from 23.5 to36 °C with differences between the coldest andthe hottest station from 5.3 to 9.2 °C.Photosynthetically active radiation (PAR) were reducedin the discharge area water column, due to turbulence.One hundred and one different taxa were identifiedwith a strong predominance of Diatoms. The chlorophylla concentration ranged from 0.3 to 6.1 μgL-1, with highest values of thephaeophytin:chlorophyll ratio found at the hottest station.The community structure did not show significativedifferences among sampling stations with respect totemperature variations. However, in the algalassemblages influenced by thermal discharges, it waspossible to observe alterations in the photosynthesisbehaviour. Phytoplankton response to short termphotosynthesis experiments was segregated according tocomposition and origin of microalgal assemblages.Samples with larger heterogeneous composition had moreconsistent oxygen production responses. Algalcommunities exposed to hot effluent showed differentdegrees of photosynthesis rate reduction,higher light requirements (〉500 μE m2 s-1)and lower temperature (25 °C) to achieve Pmaxthan algae sampled in sites without such exposure.
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    URL: http://dx.doi.org/10.1023/A:1005161309609
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    Effect of Water Quality Parameters on the Migration of Vinyl Chloride Monomer from Unplasticized PVC Pipes (2000)
    Springer
    Water, air & soil pollution 120 (2000), S. 195-208 
    Details
    ISSN: 1573-2932
    Keywords: diffusion rate ; migration ; pH ; temperature ; total dissolved solids ; unplasticized PVC pipes ; vinyl chloride monomer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The migration of vinyl chloride monomer (VCM) from unplasticizedpolyvinyl chloride (uPVC) pipes was investigated using locallymanufactured pipes. Specimens of 33 cm long were used throughoutthe research. The investigation was carried out under differentconditions of water temperature, pH and total dissolved solidsconcentration and at different durations of exposure. The VCMconcentration in the water was evaluated using the gaschromotography (GC)/head-space technique. A VCM concentration ofmore than 2.5 ppb was detected after 30 days of exposure at45 °C. The initial VCM concentration in the uPVC pipewas predicted using equations derived from Fick's first law ofdiffusion. Water tenperature did not affect the migration ofVCM, unless it was raised to high values (i.e. 45 °C).Total dissolved solids (TDS) and pH of water were found toaffect the release of VCM from uPVC pipes. Diffusion rate of VCMwas predicted as a function of pH or TDS values.
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    URL: http://dx.doi.org/10.1023/A:1005249808374
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    Seasonal Variation in Amount and Composition of Monoterpenes Emitted by Young Pinus pinea Trees – Implications for Emission Modeling (2000)
    Springer
    Journal of atmospheric chemistry 35 (2000), S. 77-99 
    Details
    ISSN: 1573-0662
    Keywords: monoterpene emission ; Mediterranean pine ; seasonal variation ; light ; temperature ; algorithms ; model
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract Current inventories of terpenes released from vegetation consider only the short-term influences of light and temperature on emissions to simulate temporal variation during the year. We studied whole canopy emissions from young Pinus pinea during a 15-month enclosure in greenhouse chambers and examined data for other long-term influences. Mean daytime emission rates strongly increased during spring, reached an annual maximum of ≈ 200 pmol m−2 total needle area s−1 (1.1 μg g−1 leaf dry weight h−1) between mid June and mid August, strongly declined in fall and reached an annual minimum of ≈ 1 pmol m−2 s−1 (0.006 μg g−1 h−1) between January and February. Normalization to standard temperature and light conditions did not change the annual time course of emissions, but reduced summer to winter ratio from a factor of 200 to about 45. Seasonal variation was characterized also by changes in terpene composition: among the six main compounds, three (t-β-ocimene, linalool, 1.8-cineol) were exclusively emitted during sunlit hours in the main vegetation period, whereas the other (limonene, α-pinene, myrcene) were emitted day and night and throughout the seasons. The results suggest that different terpene sources in P. pinea foliage exist and that a great part of the annual emission course observed here results from seasonal influences on these sources. A global model to simulate plant emissions is proposed, which accounts for seasonal influences on emissions in addition to the short-term effects of temperature and light. The model is tested on field data and discussed for its general application.
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    URL: http://dx.doi.org/10.1023/A:1006233010748
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    On the Development of the Temperature Concept (2000)
    Springer
    Journal of thermal analysis and calorimetry 60 (2000), S. 1081-1091 
    Details
    ISSN: 1572-8943
    Keywords: second law of thermodynamics ; temperature ; thermometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A brief outline of the history of development of the temperature concept in physics is given. Simultaneously, some persisting imperfections in the conceptual basis of classical thermodynamics closely related to the first and the second law of thermodynamics are discussed.
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    URL: http://dx.doi.org/10.1023/A:1010196716770
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    Pollen content study of the lower atmosphere in León (Spain) by use of a tethered balloon (2000)
    Springer
    Aerobiologia 16 (2000), S. 187-191 
    Details
    ISSN: 1573-3025
    Keywords: aerobiology ; airborne pollen ; León (Spain) ; lower atmosphere ; meteorology ; mixing ratio ; relative humidity ; tethered balloon ; temperature ; wind speed
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This study was undertaken in order to understand thebehaviour of airborne pollen grains, namely therelationship between their concentrations andconcomitant meteorological parameters, at differentaltitudes (ground level, 200, 400 and 600 m) of thelower atmosphere and its daily variations over onesite (the experimental farm of the University ofLeón). The experimental design involved a tetheredballoon (2.25 m3), an ADAS remote meteorologicalstation and an original radio controlled three headedpollen and spore sampler (called GABIS) using theRotorod design. Each head sampled a differentaltitude, while two control samples were taken atground level. Twenty-one takeoffs could be realized inthe 5 weeks period between end of May and end of June1997. Sampling was done early in the morning and sampling time at each altitudewas of 15 minutes. Results show that 45 differenttypes of pollen grains could be collected at this timeof the year and that significant variations could beobserved in the behaviour of the pollen cloud on a dayto day basis, probably because of differentmeteorological situations. Contrary to what isgenerally believed, pollen was in most cases moreabundant at higher altitude – on average by 30% ascompared to ground level – making evident anaerobiological layer of transport at about 500 m aboveground. This was especially the case for trees (Quercus and Castanea). The atmosphere MixingRatio was the most explicative factor at 200 m, whiletemperature dominated significance analysis at both400 and 600 m.
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    Effect of Temperature on Absorption Efficiency of NO2 in Arsenite Method (2000)
    Springer
    Environmental monitoring and assessment 61 (2000), S. 285-291 
    Details
    ISSN: 1573-2959
    Keywords: adsorption ; NO2 ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The sodium arsenite method developed by Jacobs andHochheiser is one of the most widely used manualmethods for nitrogen dioxide (NO2) monitoring inambient air, particularly in developing countries. Asreported, the method gives 82% NO2 absorptionefficiency (NAE) in the concentration range from 40 to750 μg/m3, when only one impinger tube isemployed in the sampling train at a flow rate of 0.2lpm and for 24 h sampling duration. Accordingly,a uniform correction factor (0.82) is used indenominator to calculate the ultimate concentration ofNO2 in ambient air.In the present investigation, the effect oftemperature on absorption efficiency of NO2 isstudied employing four impinger tubes in series tocollect the maximum NO2 generated in the gasstream. The study conducted at 16, 26 and 36 °Ctemperatures shows maximum absorption efficiency(average) of 87.8% at 26°C in 1st impingertube. At lower and higher temperatures, it is foundconsiderably less. A suitable correction factor,therefore, must be applied to estimate actual NO2concentration in ambient air using arsenite method, intropical countries like India, where atmospherictemperature variations are large (less than 5°Cin winter and more than 45°C in summer).
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    URL: http://dx.doi.org/10.1023/A:1006131525148
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    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.
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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.
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    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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    Factors influencing the induction of diapausing egg production in the calanoid copepod Diaptomus leptopus (2000)
    Springer
    Aquatic ecology 34 (2000), S. 9-17 
    Details
    ISSN: 1573-5125
    Keywords: diapause ; Diaptomus ; permanent environment ; photoperiod ; pond chemistry ; proximate cues ; temperature ; temporary environment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Field and laboratory studies were carried out between 1995 and 1997 on four populations of Diaptomus leptopus found in seasonally temporary, occasionally temporary, and a permanent environment to assess the relative importance of photoperiod and temperature regimes versus other proximate local cues in inducing diapause egg production. Patterns of diapausing and subitaneous egg production were determined by observation of individual females bearing clutches that were produced in the field. A laboratory common-garden experiment was performed to assess the effects of four different regimes of temperature and photoperiod on the induction of diapause. Patterns of diapausing egg production differed among ponds: diapause occurred early in the seasonally temporary environment and occurred rarely in the permanent environment. In the common-garden experiment, populations exhibited substantial changes in the onset of diapause when compared to patterns found under field conditions. These results provide indirect evidence that the different populations respond to available cues of environmental change in different ways in nature, or that environmental cues vary among habitats.
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    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.
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    Effects of in vitro treatments on leaf area growth of potato transplants during acclimatisation (2000)
    Springer
    Plant cell, tissue and organ culture 61 (2000), S. 59-67 
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    ISSN: 1573-5044
    Keywords: alar ; in vitro plantlet ; mannitol ; nitrogen ; rooting ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The importance of leaf area of in vitro propagated potato (Solanum tuberosum L.) plantlets for further growth during acclimatisation and the after-effects of in vitro treatments on growth were examined. The in vitro treatments included different levels of alar, nitrogen or mannitol or different temperatures during the last in vitro phase, the rooting phase. Leaf area or ground cover was recorded one day after planting to soil and at the end of the first phase of ex vitro growth, the acclimatisation phase. Regression analysis showed that leaf area of a transplant at the end of acclimatisation phase was positively influenced by leaf area of the same plantlet at the beginning of the phase. The relative increase in leaf area during acclimatisation (increase/early leaf area) was linearly related to the inverse of the early leaf area, indicating almost comparable relative increases for plantlets having larger early leaf areas, but more variable responses for plantlets having smaller early leaf areas. In vitro treatments mainly affected leaf area of transplants through their effects on early leaf area. Adding alar, reducing nitrogen and reducing temperature increased leaf area. Reducing mannitol increased ground cover. A lower nitrogen concentration and higher temperature in some cultivars had slight negative effects on the relative increase in leaf area after acclimatisation. For nitrogen these negative effects were less significant than the positive effects through early leaf area. Results stress the importance of manipulation of leaf area in vitro to enhance plant performance in later stages of growth.
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    The effect of temperature on shell size and growth rate in Krithe praetexta praetexta (Sars) (2000)
    Springer
    Hydrobiologia 419 (2000), S. 141-148 
    Details
    ISSN: 1573-5117
    Keywords: Crustacea ; Ostracoda ; Krithe praetexta praetexta ; life cycle ; ontogeny ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effect of temperature on growth rate, shell size and shell shape in Krithe praetexta praetexta (Sars) was studied in four thermocultures. From July 1995 to June 1996, the cultures were kept in a continuously flowing open system pumping water from the intermediate watermass of the Gullmarn fjord, west coast of Sweden. Three cultures were kept at constant temperatures of 5, 10 and 14 °C, respectively. The fourth (reference) culture largely followed the natural variation in temperature. At the termination of the experiment, all living ostracods from a 125 μm sieve were sampled from the cultures. Population age structures were analysed for the various thermocultures of K. praetexta praetexta. These were more shifted towards later ontogenetic stages with higher temperature, i.e. the ontogenetic development was more rapid in the warmer cultures. An alternative explanation is due to diapause causing cohorts to accumulate in some ontogenetic stages only when the temperature is constant. The differences in shell size of K. praetexta praetexta among the thermoconstant cultures were not statistically significant.
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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 
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    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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    Effect of Boron on the Structure and Composition of Cobalt Silicides (2000)
    Springer
    Powder metallurgy and metal ceramics 39 (2000), S. 599-602 
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    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.
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    Responses of Porphyra linearis (Rhodophyta) to environmental factors under controlled culture conditions (2000)
    Springer
    Journal of applied phycology 12 (2000), S. 535-542 
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    ISSN: 1573-5176
    Keywords: desiccation ; growth ; growth model ; inorganic carbon ; nutrients ; photoperiod ; photosynthesis ; pigments ; Porphyra linearis ; PPF ; respiration ; temperature ; water velocity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effect of environmental parameters on the growthof Porphyra linearis gametophytes was examinedunder controlled conditions, and related to themultilinear regression growth model recently developedfor this seaweed under coastal conditions in theeastern Mediterranean. Growth chambers, a gradienttable, special culture devices and analytical methodswere combined for this culture study.The major factors significantly controlling thegrowth rate of the P. linearis gametophytein glass dishes were: photoperiod, temperature, agein culture, photosynthetic photon flux (PPF), salinityand water dynamics. Maximal growth occurred underdaylength of 12 h, medium temperature (15–20 °C), low PPF (70–140 μmol photon m-2s-1), ambient salinity (30–40 ppt), 1–3 h ofdaily air exposure, and water velocity of 4 cm s-1.Photosynthesis and respiration rates weredominantly affected by daylength and temperature,while the concentration of pigments was dominantlyaffected by PPF and temperature.These conditions correspond well to the optimalnatural growth environment of this local species andare in agreement with the optimum estimated throughthe recently developed outdoor mathematical growthmodel.
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    Responses of rotifers and cladocerans to Microcystis aeruginosa (Cyanophyceae): A demographic study (2000)
    Springer
    Aquatic ecology 34 (2000), S. 227-242 
    Details
    ISSN: 1573-5125
    Keywords: cladocerans ; demography ; Microcystis aeruginosa ; rotifers ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The response of selected rotifers and cladocerans to Microcystis aeruginosa, offered as colonies and single cells, was compared to that on a diet of Chlorella vulgaris using the life table demography approach. The test zooplankton species were Simocephalus vetulus, Daphnia carinata, Moina macrocopa, Scapholeberis kingi, Ceriodaphnia cornuta, Brachionus calyciflorus and Hexarthra mira. To detect the development of resistance to toxins from Microcystis in zooplankton, in addition to the laboratory cultured strain of Ceriodaphnia cornuta, another strain of the same species was also used (designated as C. cornuta 2, this was collected from a pond containing Microcystis and cultured in the laboratory on Chlorella for a few weeks prior to experimentation). Experiments were conducted at 20 °C and 30 °C. Survivorship was high on Chlorella in most species but low on diets of Microcystis. Except for C. cornuta 2, S. kingi and S. vetulus, all other test species were adversely affected by Microcystis. The ability to utilise Microcystis improved at 30 °C in M. macrocopa, D. carinata and H. mira. The longest mean lifespan was recorded for C. cornuta 2 (25.3 ± 4.86 d) and the lowest for B. calyciflorus (0.58 ± 0.05 d). The highest net reproductive rate was observed for C. cornuta 1 (44.9 ± 4.88) and the longest generation time of 26.6 ± 2.13 d for S. vetulus. Among the cladocerans that showed positive values of population growth rate (r), M. macrocopa had the highest of 0.96 ± 0.04 per day.
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    Seasonal variations in copepod body length: a comparison between different species in the Lagoon of Venice (2000)
    Springer
    Aquatic ecology 34 (2000), S. 243-252 
    Details
    ISSN: 1573-5125
    Keywords: body size ; chlorophyll concentration ; salinity ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The seasonal variation in length of the most abundant copepod species in the lagoon of Venice were compared and the relative influence of temperature, chlorophyll concentration and salinity examined. Temperature seems to be the primary factor influencing copepod body length in the lagoon of Venice, but the different species vary markedly in their response. Calanoid copepods (Acartia clausi, A. tonsa, Paracalanus parvus and Centropages ponticus) showed a more definite trend of size variation with temperature than the cyclopoids (Oithona nana and O. similis) and the harpacticoid Euterpina acutifrons. The size of the poecilostomatoids Oncaea media and O. subtilis was not affected by temperature, and was almost constant over time. Differences in the metabolic rates, longevity and specialization of calanoid, cyclopoid and harpacticoid copepods could explain their different responses to temperature.
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    Fate of bacterial pathogens in cattle dung slurry subjected to anaerobic digestion (1999)
    Springer
    World journal of microbiology and biotechnology 15 (1999), S. 335-338 
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    ISSN: 1573-0972
    Keywords: Anaerobic digestion ; biogas ; pathogens ; survival ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The survival of certain pathogenic bacteria was studied in anaerobic batch digesters at room temperature (18–25 °C) as well as at 35 °C under laboratory conditions. The survival of Escherichia coli and Salmonella typhi at room temperature was upto 20 days whereas at 35 °C it was only upto 10 days. Shigella dysenteriae was found to be the most sensitive organism which could survive upto 10 days at room temperature and upto 5 days at 35 °C. The longest survival was observed in case of Streptococcus faecalis which could survive upto 35 days at room temperature and 15 days at 35 °C. The survival time of Salmonella typhi increased when the solid contents of the digester were elevated from 9% to 15%.
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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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    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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    Electrochemical synthesis of cupric oxide powder Part II: Process conditions (1999)
    Springer
    Journal of applied electrochemistry 29 (1999), S. 81-85 
    Details
    ISSN: 1572-8838
    Keywords: cupric oxide ; powder ; current density ; temperature ; sodium sulfate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Notes: Abstract Electrosynthesis of cupric oxide powder was carried out on a laboratory scale in an electrochemical cell under various experimental conditions. The electrolysis was appraised in terms of the particle size of the cupric oxide product and the anodic dissolution of the copper electrode. Using a previously determined pH value of 7.50, the other optimum electrolysis operating conditions established were a current density of 4000Am−2, temperature of 353K, and Na2SO4 concentration of 0.5m. The optimum values of current efficiency, cell voltage and specific energy consumption for the electrochemical synthesis of cupric oxide powder were determined.
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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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    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
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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 
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    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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    Sedimentation patterns of diatoms in Lake Holzmaar, Germany - (on the transfer of climate signals to biogenic silica oxygen isotope proxies) (1999)
    Springer
    Journal of paleolimnology 21 (1999), S. 437-448 
    Details
    ISSN: 1573-0417
    Keywords: diatoms ; temperature ; sediment traps ; seasonal succession ; resuspension ; Lake Holzmaar
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences
    Notes: Abstract The seasonal sedimentation pattern of diatom valves in Lake Holzmaar was investigated during 1995 by deploying sediment traps at three different lake depths. According to the sedimentation pattern, the major reproduction zone of diatoms was restricted to the upper 6 m of the water body. The population growth started late in April and blooms of Cyclotella cf. comensis Grun., which dominates the plankton diatoms, and Fragilaria crotonensis Kitton were collected in traps during June and September, and July, respectively. During summer, the seasonal sedimentation pattern of each taxon, as collected in the upper traps, was reflected in the concentrations in the lowest trap. However, in May and from September onwards, the community composition in the lowest trap and augmented trapping rates suggest both sediment focusing and resuspension of bottom sediments. The temperature signals as recorded by δ18O values of diatom valves should, therefore, reflect integrated temperatures between 0 and 6 m depth. However, temperatures during summer and autumn are expected to be accentuated in the sedimentary record since the isotopic signal is weighted by both the number and the weight-mass of the valves. During summer, the transfer of these signals by the sedimenting diatoms retains the information pattern recorded, while in spring and autumn/winter additional influxes caused by resuspension may somewhat alter those temperature informations. The proxy signals finally stored in the sediments, may, therefore, not precisely represent the successive temperatures currently recorded during 1995 within mid-lake.
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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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    Effects of temperature and photoperiod on development and oviposition of the legume flower thrips, Megalurothrips sjostedti (1999)
    Springer
    Entomologia experimentalis et applicata 93 (1999), S. 149-155 
    Details
    ISSN: 1570-7458
    Keywords: Megalurothrips sjostedti ; temperature ; photoperiod ; development ; pre-oviposition ; oviposition ; diapause
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Megalurothrips sjostedti is an economic pest of cowpea in tropical Africa. There are no reports of the effect of temperature on the development of the pest and no diapause has been detected. The developmental rate and reproduction of M. sjostedti was studied under six constant temperatures (14, 17, 20, 23, 26 and 29 °C ) and a photoperiod of L12:D12 in the laboratory. Total developmental time ranged from 33.1 days at 14 °C to 19.2 days at 26 °C. At 29 °C, all larvae died during hatching. Egg, larval and pupal stages required 94.3, 97.1 and 105.3 deg-days (DD) above a threshold of 8.2, 9.1 and 10.4 °C, respectively, to complete development. Total developmental cycle was completed at 163.9 DD above a threshold of 12.6 °C. Adult longevity was lowest (11.1 days) at 29 °C and highest (28.7 days) at 14 °C. At constant temperatures, the highest pre-oviposition period was observed at 29 °C under a photoperiod of L16:D8. Egg production also ceased at this temperature/photoperiod combination. Total fecundity was highest at 26 °C under L10:D14. At cyclical temperatures, pre-oviposition period was longest (12.4 days) at 20/29 °C under L16:D8. Total fecundity was highest (168.4 eggs) at 14/26 °C under L10:D14, and lowest (8.2 eggs) at 20/29 °C under L16:D8. The significance of these findings in the management of M. sjostedti is discussed.
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    Influence of temperature on bionomics of cotton aphid, Aphis gossypii, on cotton (1999)
    Springer
    Entomologia experimentalis et applicata 90 (1999), S. 25-35 
    Details
    ISSN: 1570-7458
    Keywords: Aphis gossypii ; development ; survival ; fecundity ; intrinsic rate of increase ; life table ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Life table parameters of Aphis gossypii Glover (Homoptera: Aphididae) on Gossypium hirsutum L. were determined at six temperatures (10, 15, 20, 25, 30, and 35 ± 0.5 °C) in the laboratory. Relationships of life table parameters with temperature were described with mathematical equations. Development was fastest at 30 °C, with a pre-larviposition period of 4.6 d. Survival to adult was greatest at 25 °C (81%). Fecundity was highest at 25 °C, with a total fecundity of 28.3 nymphs per female and a mean reproductive rate of 3.1 nymphs per female per day. Threshold temperatures for development in the first through fourth instar and the adult were 8.2, 8.0, 7.2, 6.2 and 7.9 °C, respectively. The durations of these stages, expressed as temperature sums above these thresholds, were 24.2, 23.7, 23.0, 25.5 and 168.8 degree-days (D°), respectively. A. gossypii achieved its maximum net reproductive number (24.4 nymphs per female) and greatest intrinsic rate of increase (0.386 d−1) at 25 °C. The high relative rate of population increase at 25 °C results in a daily population increase of 47% and a doubling time of only 1.8 d, illustrating the tremendous growth capacity of A. gossypii populations under favourable conditions. Compared to literature sources, our source of A. gossypii, fed on cotton, showed a comparatively great heat tolerance.
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    The smaller fruit tortrix, Grapholita lobarzewskii: predicting the phenology of adult emergence (1999)
    Springer
    Entomologia experimentalis et applicata 93 (1999), S. 297-302 
    Details
    ISSN: 1570-7458
    Keywords: smaller fruit tortrix ; Grapholita lobarzewskii ; phenology ; post-diapause development ; temperature ; thermal threshold ; thermal constant ; forecasting ; modelling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The smaller fruit tortrix, Grapholita lobarzewskii Nowicki, has become a major pest in the recent past in apple orchards north of the Alps. Nevertheless little is known about the biology and the behaviour of this species. The effect of temperature on post-diapause development and survival was studied under controlled conditions in order to establish a basis for the forecasting of adult emergence. Survival was found to be highest at 17 °C and lowest at 11.8 °C. The sex ratio did not differ significantly from 1:1. Based on a linear relationship between temperature and developmental rates, thermal thresholds of 9.6 °C and 9.8 °C were determined for females and males respectively. The thermal constants, i.e., the mean developmental times in physiological time units, were found to be 342 day-degrees for females and 317 day-degrees for males, suggesting a slight protandry. Based on the mean and the variance of the developmental times, a simple temperature-driven phenology model was built using a time-varying distributed delay. The model was validated by visually comparing the predictions with independent observations on adult emergence, and by calculating the temporal deviations of the predictions. In 4 out of 5 years the mean error was less than 3 days. The model was therefore found to give reliable forecasts of the emergence of G. lobarzewskii and can be used to determine the optimal time for the exposure of pheromone traps, the application of pheromone dispensers for mating disruption, and for the timing of insecticide applications.
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    URL: http://dx.doi.org/10.1023/A:1003905026249
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    Effects of environmental factors and plant growth regulators on growth of the red alga Gracilaria vermiculophylla from Shikoku Island, Japan (1999)
    Springer
    Hydrobiologia 398-399 (1999), S. 339-347 
    Details
    ISSN: 1573-5117
    Keywords: Gracilaria ; growth ; irradiance ; plant growth regulators ; salinity ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Growth and tolerance of Gracilaria vermiculophylla (Ohmi) Papenfuss from Shikoku Island were investigated under a variation of temperature (5–30 °C), salinity (5–60‰), and photon irradiance (20–100 μmol photons m−2 s−1) in unialgal culture. G. vermiculophylla showed wide tolerances for all factors tested, characterizing a euryhaline and eurythermal species. Two clones, one of a tetrasporophyte and the other of a female gametophyte, showed different growth rates, attributable to the difference either in phase or in genotype. The optimum temperature for the growth of the tetrasporophyte clone was 15–25 °C while that of the gametophyte clone was 20–30 °C. Maximum growth of both phases was observed at 80–100 μmol m−2 s−1. G. vermiculophylla presented higher growth rates in low salinities (15–30‰). Tissue cultures were established in solid ASP 12-NTA medi um supplemented with plant growth regulators (PGR), 0.5% agar, 1.0% sucrose and 0.5% inositol. Effects of two auxins (indole-3-acetic acid (IAA), and 2,4-dichlorophenoxyacetic acid (2,4-D)), and one cytokinin (6-benzylaminopurine (BA)) were tested in concentrations ranging from 0.1 to 10.0 mg l−1. Growth of apical segments was significantly stimulated by the majority of treatments supplemented with PGR, while maximum growth of calluses was observed in treatments with low concentration of auxins or BA (1.0 mg l−1). All treatments supplemented with PGR significantly promoted the growth of intercalary segments, except for IAA (1.0 mg l−1) in combination with BA (1.0 mg l−1). Growth of calluses originating from intercalary segments was observed in treatments with IAA (0.1 mg l−1), 2,4-D (10.0 mg l−1) or IAA (1.0 mg l−1) in combination with BA (0.1 mg l−1). Tr eatments with high concentration of IAA and BA (10.0 mg l−1) were lethal for apical and intercalary segments. These results show that auxin and cytokinin play a regulatory role on the growth of G. vermiculophylla in tissue culture. Furthermore, results on the effects of temperature, salinity and irradiance indicate that G. vermiculophylla could be cultivated in brackish temperate environments with potential for economic purposes and for pollution management.
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    Influence of Solar Ultraviolet Radiation on Early Life-history Stages of the Bluegill Sunfish, Lepomis macrochirus (1999)
    Springer
    Environmental biology of fishes 55 (1999), S. 307-319 
    Details
    ISSN: 1573-5133
    Keywords: embryo survival ; dissolved organic carbon ; DOC ; nest depth distribution ; development times ; temperature ; underwater UVR environments
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We examined the effect of UVR on the success of early life history stages of Lepomis macrochirus in two lakes with contrasting underwater UVR environments. We tested the prediction that when exposed to similar amounts of UVR, bluegill embryos from lakes with high UVR environments have lower mortality than those from lakes with low UVR. We measured embryo survival in the two lakes by performing three experiments in which ambient UVR was manipulated. Embryos responded similarly to UVR exposure regardless of the lake of origin. However, UV-B in UVR transparent lakes is a potentially important factor in the success of early life history stages of the bluegill. A survey of the natural nesting depths in the two lakes revealed that the median depth at which bluegills construct their nests was greater in Lake Giles (high underwater UVR environment) than in Lake Lacawac (low underwater UVR environment).
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    Effects of thermal regime on energy and nitrogen budgets of an early juvenile Arctic charr, Salvelinus alpinus, from Lake Inari (1999)
    Springer
    Environmental biology of fishes 54 (1999), S. 219-227 
    Details
    ISSN: 1573-5133
    Keywords: temperature ; energy partitioning ; nitrogen balance ; salmonid ; fish
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The feed intake, growth, oxygen consumption and ammonia excretion of juvenile Arctic charr were measured over period of four weeks at different temperatures which were either constant (11.0, 14.4, 17.7 °C) or fluctuated daily (14.3 ± 1 °C). Maximum feed intake was estimated to occur at 14.3 °C, while oxygen consumption and nitrogen excretion were highest at the highest temperature, and growth rate was estimated to be highest at 13.9 °C. Feed conversion efficiency was estimated to be highest at 13.2 °C, where over 62.7% of ingested energy was allocated to growth. Metabolic rate accounted for 16–30% of ingested energy and nitrogen excretion was under 3% of ingested energy. The nitrogen budget was under similar thermal influences to the energy budget. Thermal fluctuation increased metabolic rate, but not feed intake, leading to a reduction in feed conversion efficiency under fluctuating temperature conditions.
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    Methane emissions from wet grasslands on peat soil in a nature preserve (1999)
    Springer
    Biogeochemistry 44 (1999), S. 205-220 
    Details
    ISSN: 1573-515X
    Keywords: grassland ; ground water level ; methane ; peat ; temperature ; wetland
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract The area of wet grasslands on peat soil in the Netherlands is slowly increasing at the expense of drained, agriculturally used grasslands. This study aimed (i) to assess the contribution of wet grasslands on peat soil to methane (CH4) emissions, and (ii) to explain differences among sites and between years in order to improve our understanding of controlling factors. For these purposes, a field study was conducted in the period 1994–1996 in the nature preserve “Nieuwkoopse Plassen”, which is a former peat mining and agricultural area. Net CH4 emissions were measured weekly to monthly with vented closed flux chambers at three representative sites, and at ditches near these sites. Three-years average of CH4 emissions was 7.9 g CH4 m- 2 yr-1 for Drie Berken Zudde, 13.3 for Koole, and 20.4 for Brampjesgat. Ditches near the sites emitted 4.2–22.5 g CH4 m-2 yr-1. The time-course of CH4 emissions for all experimental sites and years was fit with a multiple linear regression model with ground water level and soil temperature as independent variables. Lowering or raising the ground water level by 5 cm could decrease or increase CH4 emissions by 30–50%. Therefore, ground water level management of these grasslands should be done with care.
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    URL: http://dx.doi.org/10.1023/A:1006061814731
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    Methane emissions from wet grasslands on peat soil in a nature preserve (1999)
    Springer
    Biogeochemistry 44 (1999), S. 205-220 
    Details
    ISSN: 1573-515X
    Keywords: grassland ; ground water level ; methane ; peat ; temperature ; wetland
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract The area of wet grasslands on peat soil in the Netherlands is slowly increasing at the expense of drained, agriculturally used grasslands. This study aimed (i) to assess the contribution of wet grasslands on peat soil to methane (CH4) emissions, and (ii) to explain differences among sites and between years in order to improve our understanding of controlling factors. For these purposes, a field study was conducted in the period 1994–1996 in the nature preserve “Nieuwkoopse Plassen”, which is a former peat mining and agricultural area. Net CH4 emissions were measured weekly to monthly with vented closed flux chambers at three representative sites, and at ditches near these sites. Three-years average of CH4 emissions was 7.9 g CH4 m−2 yr−1 for Drie Berken Zudde, 13.3 for Koole, and 20.4 for Brampjesgat. Ditches near the sites emitted 4.2–22.5 g CH4 m−2 yr−1. The time-course of CH4 emissions for all experimental sites and years was fit with a multiple linear regression model with ground water level and soil temperature as independent variables. Lowering or raising the ground water level by 5 cm could decrease or increase CH4 emissions by 30–50%. Therefore, ground water level management of these grasslands should be done with care.
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    URL: http://dx.doi.org/10.1007/BF00992979
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    Fatty acid composition of the ingested food only slightly affects physicochemical properties of liver total phospholipids and plasma membranes in cold-adapted freshwater fish (1999)
    Springer
    Fish physiology and biochemistry 20 (1999), S. 1-11 
    Details
    ISSN: 1573-5168
    Keywords: phospholipids ; plasma membranes ; fatty acids ; molecular species ; temperature ; membrane fluidity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The fatty acid content, fatty acid molecular species composition, and fluidity of phospholipid vesicles and plasma membranes of livers of fish feeding on phytoplankton (silver carp, Hypophthalmichtys molitrix), zooplankton, (big head carp, Hypophtalmitrix nobilis), higher plants, (grass carp, Ctenopharyngodon idella), and omnivorous fish, (common carp, Cyprinus carpio), adapted to reduced temperatures, was determined. Levels of long chain polyunsaturated fatty acids (PUFAs) were highest in silver and big head carp and lowest in common carp. Differences in long chain PUFAs were poorly reflected in fluidity, determined either by fluorescence anizotropy of 1,6-diphenyl 1,3,5-hexatriene or rotational correlation time of 16-doxyl- stearic acid, of phospholipid vesicles. Phospholipid vesicles of C. caripo and C. idella proved to be slightly more rigid than of H. molitrix and H. nobilis below ca. 15 °C. These differences were not seen with isolated plasma membranes assessed with 1,6-diphenyl 1,3,5-hexatriene. Using electron spin resonance spectroscopy plasma membranes from H. molitrix proved to be more fluid than those from C. carpio below ca. 15 °C. Phosphatidylethanolamines were abundant in 1-monounsaturated, 2-polyunsaturated (18:1/22:6, 18:1/20:4) species with H. molitrix and H. nobilis more rich in these species than C. carpio and C. idella. It is suggested that differences in fluidities of phospholipid vesicles below 15 °C is due to differences in levels of the above molecular species. In native membranes these differences may be masked by proteins and other membrane components. It is also suggested that it is not the fatty acid composition of the ingested food but the specific response of the fish to temperature that is the most important factor controlling the physicochemical properties of membranes during thermal adaptation.
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    Effects of acclimation temperatures of 7 and 14 °C on the contractility of Atlantic salmon (Salmo salar) intestinal smooth muscle in vitro (1999)
    Springer
    Fish physiology and biochemistry 21 (1999), S. 277-284 
    Details
    ISSN: 1573-5168
    Keywords: temperature ; intestine ; nerve stimulation ; serotonin ; substance P ; acetylcholine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The contractility of intestinal smooth muscle of Atlantic salmon (Salmo salar) acclimatized to temperatures of 7 and 14 °C was compared over a prolonged period of time (9 months) in freshwater. Initial studies were carried out on intestine isolated from Atlantic salmon to estimate optimal conditions for contractility. Subsequent studies were carried out with the neurotransmitter/agonist 5-HT and TS, which activates neuronal elements in the intestine, in a Krebs-Henseleit solution containing HEPES buffer maintained at pH 7.85 and at the temperature of the experimental group (i.e., 7 or 14 °C). There was a significant interaction with time and temperature for the maximal response of 5-HT (p=0.005), effective concentration producing 50% of the maximal response (EC50) to 5-HT (p=0.026) and maximal response to TS (p=0.002), demonstrating that gastrointestinal contractility of Atlantic salmon is altered by both time (month) and temperature. No significant changes were found with the effective frequency producing 50% of the maximal response (EF50) to TS. The potency (EC50 of 5-HT) increase between 7 and 14 °C was statistically significant (p=0.026) but the small differences found with potency were most likely not physiologically significant. A time shift was recognized in the maximal responses to 5-HT, by applying a time variable to equations for the curves of the responses. This demonstrated that the curves are similar for both temperatures but alterations in the time of the maximal response changes was different. Thus, there is a delay in the time (month) changes of gastrointestinal contractility related to acclimation temperature and would be an area for future study.
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    Photosynthetic and respiratory responses of the agarophyte Gelidiella acerosa collected from tidepool, intertidal and subtidal habitats (1999)
    Springer
    Hydrobiologia 398-399 (1999), S. 321-328 
    Details
    ISSN: 1573-5117
    Keywords: photosynthesis ; respiration ; Gelidiella acerosa ; culture ; tidal habitat ; salinity ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Several samples of the red seaweed, Gelidiella acerosa (Forssk.) Feldmann & Hamel occurring in tidepools, high intertidal rocks, and shallow subtidal areas on a reef flat in Ilocos Norte, northern Philippines were studied in terms of their photosynthetic and respiratory responses (μl O2 gDW−1 h−1) to four salinity (22, 28, 34, 40‰) and three temperature (22, 28, 34 °C) combinations. The upper intertidal plants tolerated low salinities (22–28‰) better than high salinities (34–40‰), while tidepool and subtidal plants were not affected. Temperatures of 22 through 34 °C resulted in a one-fold increase in their photosynthetic rates and insignificant differences in their respiratory rates while tidepool and subtidal plants almost doubled their photosynthetic rates and their respiration rates increased by about 5–50 times. There were no interaction effects. Therefore, intertidal plants appe ared to be more tolerant to wide temperature fluctuations and low salinity levels; while tidepool and subtidal plants were least affected by salinity variations but were quite sensitive to temperature fluctuations. Vegetative and tetrasporic plants had similar photosynthetic and respiratory responses to salinity and temperature variations, although vegetative plants had significantly higher net photosynthesis under the minimum and maximum temperatures tested (22 and 34 °C). Reproductive G. acerosa showed greater tolerance to temperature fluctuations. These responses indicated that physiological changes may have occurred when the species became reproductive. Tolerance of G. acerosa to low salinities suggests that lowering the salinities in culture tanks could be used to eradicate contaminants, i.e., dinoflagellates and filamentous green algae. Temperature of 28 °C appeared to be optimum for all plant types as reflected by their high photosynthetic and low respiratory rates .
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    A theoretical analysis and field evaluation of a light and temperature model of production by Ecklonia cava (1999)
    Springer
    Hydrobiologia 398-399 (1999), S. 361-373 
    Details
    ISSN: 1573-5117
    Keywords: production ; mathematical model ; Ecklonia cava ; light ; temperature ; photosynthesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The dependence of photosynthesis on light and temperature is modelled through analysis of transition probabilities of photosystems. In the model, two transition probabilities are functions of light, and one transition probability is a function of temperature. The estimated light-saturated photosynthesis of Ecklonia cava blades at 20 °C was 0.037 mg C cm−2 h−1. The value of the activation energy, the standard enthalpy and the standard entropy were estimated to be 56.5 kJ mol−1, 204 kJ mol−1 and 678 J mol−1 K−1, respectively. A production model (an integral photosynthesis model) for an E. cava stand was developed using the photosynthesis model. Production calculated by the model agreed well with observed data during the growing period of an E. cava stand at a field observation site on the west side of Miura Peninsula, Japan. Results of the analysis of the effects of irradiance and temperature on the production of the E. cava community by the model are: 1. Production decreased with irradiance decrease. The estimated compensation irradiance was 26.5 μmol photons m−2 s−1 when the biomass was 3 kg wet mass m−2 (blade:stipe ratio = 2 kg m−2:1 kg m−2) and the temperature was 20 °C. 2. The optimum temperature decreased when irradiance decreased and when biomass increased. The highest estimated value for the optimum temperature was 24.0 °C. The estimated optimum temperature was 18.2 °C when the biomass was 12 kg wet mass m−2 and the photon irradiance was 200 μmol photons m−2 s−1. 3. The amount of biomass that resulted in the maximum production was influenced by irradiance and temperature. At 400 μmol photons m−2 s−1 and 20 °C, the estimated value of the biomass (blade:stipe = 2:1) giving the maximum pr oduction was about 5.3 kg wet mass m−2. However, at 100 μmol photons m−2 s−1 and 24 °C, the estimated value was about 3.0 kg wet mass m−2. The estimated values of the maximum production under the two conditions were 1.05 and 0.30 g C m−2 h−1, respectively.
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  • 82
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    Optimum production conditions for different high-quality marine algae (1999)
    Springer
    Hydrobiologia 403 (1999), S. 97-107 
    Details
    ISSN: 1573-5117
    Keywords: Algal growth rate ; salinity ; temperature ; pH ; Nannochloropsis ; Tetraselmis ; Isochrysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The possibility of improving the growth rate of different high-quality marine algae was studied. Optimum culture conditions relative to salinities, temperatures and pH levels were defined for three species of Nannochloropsis, Tetraselmis and Isochrysis. In Nannochloropsis, the optimum production ranges were as follows: 20–40‰, 19–21 °C, without using CO2. The optimum conditions for Tetraselmis were: 20–35‰, 19–21 °C, without using CO2. For Isochrysis, the optimum conditions were: 25–35‰, 24–26 °C, also without using CO2.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003725626504
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  • 83
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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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1021808317416
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  • 84
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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).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1021812418325
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  • 85
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    Comparing Quiet Sun and Coronal Hole Regions with CDS/SOHO (1999)
    Springer
    Space science reviews 87 (1999), S. 345-348 
    Details
    ISSN: 1572-9672
    Keywords: coronal hole ; quiet Sun ; density ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Spectra from the Coronal Diagnostic Spectrometer on board SOHO are used to compare density and temperature in coronal hole and quiet Sun regions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005166417805
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  • 86
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    Diapause Induction and Termination in Eggs of the Fruit Tree Red Spider Mite Panonychus Ulmi in Northern Greece (1999)
    Springer
    Experimental and applied acarology 23 (1999), S. 669-679 
    Details
    ISSN: 1572-9702
    Keywords: Panonychus ulmi ; dipause eggs ; overwintering ; dipause termination ; temperature ; photoperiod
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In apple orchards in northern Greece, females of Panonychus ulmi Koch were found to lay diapause eggs from late August to the beginning of October. The course of diapause termination in the field was determined by transferring diapause eggs during winter and early spring from apple orchards with the varieties ‘Starkinson’ and ‘Firiki’ to short days (LD 8:16) (1992–1996), and long days (LD 16:8) (1994–1995), both at 20 °C. Percentages of diapause termination were very low to zero from October to the beginning of January, then progressively increased throughout January and February. Diapause termination in 50% of the eggs occurred in the first half of February in lowland mite populations irrespective of the year and location from which the eggs originated, and about one month earlier in a population originating from an altitude of 300 m. For each sampling date throughout the winter, the mean number of days required for 50% egg hatch at 20 °C (T50%) was similar under either a long (LD 16:8) or a short (LD 8:16) photoperiod. Diapause eggs collected in October 1995 from two orchards and maintained at 0, 5, 10 and 15 °C for various periods were subsequently transferred to 20 °C and LD 8:16, where TP50% was determined. It was shown that temperature, duration of maintenance at the different temperatures and the orchard from which the eggs originated had a significant effect on T50% and therefore on diapause development. Additionally, in our strains diapause intensity was much weaker than in strains from more northern latitudes and was terminated even without any cold exposure. The variation in diapause intensity in different strains of P. ulmi may have an adaptive significance for this widespread species.
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    URL: http://dx.doi.org/10.1023/A:1006232821653
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  • 87
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    Langfristige Zunahme früher Bruten beim Teichrohrsänger (Acrocephalus scirpaceus) in einem südwestdeutschen Untersuchungsgebiet (1999)
    Springer
    Journal of ornithology 140 (1999), S. 81-86 
    Details
    ISSN: 1439-0361
    Keywords: Reed Warbler ; timing of breeding ; spring arrival ; global climate change ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung In einem Untersuchungsgebiet am westlichen Bodensee (Halbinsel Mettnau) zeichnet sich zwischen 1976 und 1997 eine deutliche Zunahme früh ausgeflogener Teichrohrsänger ab, was auf ein früheres Brüten schließen läßt. Weiterhin hat sich die Erstankunft des Teichrohrsängers am Bodensee in den letzten 16 Jahren (1982–1997) im Vergleich zum Zeitraum 1961 bis 1980 um genau eine Woche verfrüht (im Mittel vom 26.4. auf den 19.4.). Während sich zwischen der jährlichen Erstankunft des Teichrohrsängers am Bodensee und der Zahl früh ausgeflogener Jungvögel kein statistisch gesicherter Zusammenhang finden läßt, ist die Temperatur in der ersten Maihälfte ein guter (statistisch signifikanter) Indikator für die Zahl früh ausgeflogener Teichrohrsänger. Die vorliegende Untersuchung zeigt, daß sich offenbar auch Langstreckenzieher an die sich abzeichnende Klimaveränderung anzupassen beginnen.
    Notes: Summary Data from a standardized mist-netting programme (the so-called "MRI-Programm") were used to assess the timing of breeding in Reed Warblers (Acrocephalus scirpaceus) at Lake Constance (South Germany). The number of Reed Warblers fledged early in the season increased significantly between 1976 and 1997 (rs=0.614; p〈0.01). This is most probably due to a long-term increase in spring temperature as suggested by the high correlation between the number of early-fledged Reed Warblers and mean temperature in the first half of May (rs=0.416; p〈0.01). While in the period from 1961 to 1980 the mean date of spring arrival was on the 26th of April, it shifted towards the 19th April from 1981 to 1997. However, the number of early-fledged Reed Warblers and the date of spring arrival are not significantly correlated. The lack of a significant correlation may be due to a number of reasons, for instance early arriving birds do not belong to the local population or there could be an observational bias among years. Yet, the most likely explanation is that the timing of breeding in Reed Warblers is triggered by vegetation growth and food supply rather than by the timing of spring arrival. There is growing body of evidence from this and other studies that the recent climate change is responsible for the shift in both the timing of migration and breeding in birds.
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    URL: http://dx.doi.org/10.1007/BF02462091
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  • 88
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    Technique for Measuring Thermophysical Properties of Refractory Metals at Supercritical Temperatures (1999)
    Springer
    International journal of thermophysics 20 (1999), S. 1257-1266 
    Details
    ISSN: 1572-9567
    Keywords: critical point ; exploding wire technique ; high-pressure cell ; numerical modeling ; specific heat ; tantalum ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A foil confined in a sapphire cell is heated by an electrical current pulse at rates from 1010 to 1011 K·s−1. Temporal evolutions of the temperature and pressure distributions in the foil is investigated by means of numerical modeling. It is demonstrated that such a technique allows reaching temperatures far above 10,000 K and pressures up to 50 kbar and provides a uniform temperature and pressure in the foil. The technique has been applied for investigation of liquid tantalum. Experimental results on temperature measurement are discussed. Data on specific heat of liquid tantalum at temperatures up to 11,000 K are reported.
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    URL: http://dx.doi.org/10.1023/A:1022631626431
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  • 89
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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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    URL: http://dx.doi.org/10.1023/A:1003727324475
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  • 90
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    Transcript accumulation and utilization of alternate and non-consensus splice sites in rice granule-bound starch synthase are temperature-sensitive and controlled by a single-nucleotide polymorphism (1999)
    Springer
    Plant molecular biology 40 (1999), S. 719-727 
    Details
    ISSN: 1573-5028
    Keywords: amylose ; splicing ; starch synthase ; temperature ; waxy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Granule-bound starch synthase (GBSS), a product of the waxy gene in rice (Oryza sativa L.), is necessary for the synthesis of amylose in the endosperm. In an extended pedigree of 89 rice cultivars, we have previously shown that all cultivars with more than 18% amylose had the sequence AGGTATA at the leader intron 5′ splice site, while all cultivars with a lower proportion of amylose had the sequence AGTTATA. This single-nucleotide polymorphism reduces the efficiency of GBSS pre-mRNA processing. It also results in alternate splicing at multiple sites, some of which have non-consensus sequences. Here we demonstrate that this same G-to-T polymorphism is also associated with differential sensitivity to temperature during the period of grain development. Cultivars with the sequence AGTTATA have a substantial increase in accumulation of mature GBSS transcripts at 18 °C compared to 25 or 32 °C. The selection of leader intron 5′ splice sites is also affected by temperature in these cultivars. A 5′ splice site −93 upstream from that used in high-amylose varieties predominates at 18 °C. At higher temperatures there is increased utilization of a 5′ splice site at −1 and a non-consensus site at +1. Potential implications of differential 5′ splice site selection and associated differences in 3′ splice site selection on transcript stability and translational efficiency are discussed.
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    URL: http://dx.doi.org/10.1023/A:1006298608408
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  • 91
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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 
    Details
    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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    URL: http://dx.doi.org/10.1023/A:1004740204876
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  • 92
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    Factors affecting food consumption and growth of walleye, Stizostedion vitreum, larvae in culture ponds (1999)
    Springer
    Hydrobiologia 400 (1999), S. 129-140 
    Details
    ISSN: 1573-5117
    Keywords: fish ; energetics ; temperature ; feeding ; prey abundance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract I examined food consumption and growth of walleye larvae in extensive culture ponds using direct methods and a bioenergetics model, and compared my results with laboratory feeding and growth studies. Walleye showed a diel pattern of increasing gut fullness during daylight hours. Larvae exhibited lower maximum food consumption rates in the ponds than predicted from previous short-term laboratory feeding studies. Direct estimates and bioenergetics model estimates of daily food consumption in the culture ponds were in poor agreement and the discrepancy varied with respect to walleye size. Food consumption rates in the ponds were related to walleye size (direct estimates) or water temperature (bioenergetics model estimates) but not zooplankton abundance. Growth exceeded 0.10 g g−1 d−1 for all but one sampling interval and the maximum growth rate in the culture pond fish was double the maximum growth rate determined in the laboratory. Growth was positively related to pond temperature and negatively related to walleye mass, but was not significantly related to zooplankton abundance. Gross conversion efficiency was negatively related to walleye mass, positively related to zooplankton abundance and not related to temperature. Food consumption and growth of walleye larvae in the field may be food-limited at much lower prey abundances than previous laboratory research has suggested.
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    URL: http://dx.doi.org/10.1023/A:1003755115000
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  • 93
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    Effects of genotype and environment on phenotypic variability in Limnocythere inopinata (Crustacea: Ostracoda) (1999)
    Springer
    Hydrobiologia 400 (1999), S. 85-114 
    Details
    ISSN: 1573-5117
    Keywords: morphology ; clone ; temperature ; salinity ; parthenogenesis ; sexual reproduction ; cluster genotype ; general purpose genotype ; clonal taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Limnocythere inopinata (Baird) is a Holarctic species, widely distributed in non-marine waters, and mainly occurring in unisexual populations. It displays polymorphic traits which could be useful for taxonomical and (palaeo)ecological purposes, if the origin of these traits could be better understood. Three clones of L. inopinata were cultured in the laboratory under various temperature and salinity conditions (i.e. temperature 15, 20 and 25 °C, salinity expressed as electrical conductivity 400, 2000, 5000 and 8000 μS cm−1). Morphological traits for both the valves (shape and size) and soft parts (11 limb setae) were observed. Field populations from Chinese salt lakes and from Austrian lakes were also compared. The freshwater population from Mondsee and its derived clone M develop larger valves than those of the other two clones, clone N (from Neusiedlersee) and clone S (from Seewinkel, Oberer Stinkersee), which live exclusively in saline (alkaline) water. Parthenogenetic specimens from the freshwater lake Mondsee and sexually reproducing females from the Chinese salt lakes both have sub-rectangular valves with straight dorsal margin; the saline clones and populations have highly arched valves with rounded dorsal margin. No direct effects of temperature or salinity on valve ornamentation (reticulation, nodation) have been found. At least for nodation, a genetic factor seems apparent, as the saline clones N and S are never nodose, while the freshwater animals from Mondsee and the sexual animals from the Chinese salt lakes can be both with or without nodes. In the former case, number and position of nodes are variable. Both absolute and relative length of limb setae can be affected by environmental factors and by genotype, and this is the first time that this has been demonstrated in non-marine ostracods. Based on the present observations and experiments, it is concluded that L. inopinata is a variable, polymorphic species, consisting of a (semi-) continuous morphological cluster, in which both clonal genotypes and sexual haplotypes are nested. Therefore, Limnocythere sappaensis Staplin and L. binoda Huang are considered synonyms of L. inopinata; L. mongolica Daday is a possible synonym; L. sanctipatricii sensu Huang and L. dubiosa sensu Huang from Lake Qinghai are most likely erroneous identifications. Apparently recognisable clones with typical ecologies cannot be allocated a taxonomic rank, as this does not reflect a phylogenetic reality. Such links between recognisable morphologies and typical ecological ranges are useful for palaeoenvironmental reconstructions, but are applicable at a regional scale only.
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    URL: http://dx.doi.org/10.1023/A:1003759125903
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  • 94
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    Factors affecting food consumption and growth of walleye, Stizostedion vitreum, larvae in culture ponds (1999)
    Springer
    Hydrobiologia 400 (1999), S. 129-140 
    Details
    ISSN: 1573-5117
    Keywords: fish ; energetics ; temperature ; feeding ; prey abundance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract I examined food consumption and growth of walleye larvae in extensive culture ponds using direct methods and a bioenergetics model, and compared my results with laboratory feeding and growth studies. Walleye showed a diel pattern of increasing gut fullness during daylight hours. Larvae exhibited lower maximum food consumption rates in the ponds than predicted from previous short-term laboratory feeding studies. Direct estimates and bioenergetics model estimates of daily food consumption in the culture ponds were in poor agreement and the discrepancy varied with respect to walleye size. Food consumption rates in the ponds were related to walleye size (direct estimates) or water temperature (bioenergetics model estimates) but not zooplankton abundance. Growth exceeded 0.10 g g−1 d−1 for all but one sampling interval and the maximum growth rate in the culture pond fish was double the maximum growth rate determined in the laboratory. Growth was positively related to pond temperature and negatively related to walleye mass, but was not significantly related to zooplankton abundance. Gross conversion efficiency was negatively related to walleye mass, positively related to zooplankton abundance and not related to temperature. Food consumption and growth of walleye larvae in the field may be food-limited at much lower prey abundances than previous laboratory research has suggested.
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    URL: http://dx.doi.org/10.1023/A:1003755115000
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  • 95
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    Effects of genotype and environment on phenotypic variability in Limnocythere inopinata (Crustacea: Ostracoda) (1999)
    Springer
    Hydrobiologia 400 (1999), S. 85-114 
    Details
    ISSN: 1573-5117
    Keywords: morphology ; clone ; temperature ; salinity ; parthenogenesis ; sexual reproduction ; cluster genotype ; general purpose genotype ; clonal taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Limnocythere inopinata (Baird) is a Holarctic species, widely distributed in non-marine waters, and mainly occurring in unisexual populations. It displays polymorphic traits which could be useful for taxonomical and (palaeo)ecological purposes, if the origin of these traits could be better understood. Three clones of L. inopinata were cultured in the laboratory under various temperature and salinity conditions (i.e. temperature 15, 20 and 25 °C, salinity expressed as electrical conductivity 400, 2000, 5000 and 8000 μS cm−1). Morphological traits for both the valves (shape and size) and soft parts (11 limb setae) were observed. Field populations from Chinese salt lakes and from Austrian lakes were also compared. The freshwater population from Mondsee and its derived clone M develop larger valves than those of the other two clones, clone N (from Neusiedlersee) and clone S (from Seewinkel, Oberer Stinkersee), which live exclusively in saline (alkaline) water. Parthenogenetic specimens from the freshwater lake Mondsee and sexually reproducing females from the Chinese salt lakes both have sub-rectangular valves with straight dorsal margin; the saline clones and populations have highly arched valves with rounded dorsal margin. No direct effects of temperature or salinity on valve ornamentation (reticulation, nodation) have been found. At least for nodation, a genetic factor seems apparent, as the saline clones N and S are never nodose, while the freshwater animals from Mondsee and the sexual animals from the Chinese salt lakes can be both with or without nodes. In the former case, number and position of nodes are variable. Both absolute and relative length of limb setae can be affected by environmental factors and by genotype, and this is the first time that this has been demonstrated in non-marine ostracods. Based on the present observations and experiments, it is concluded that L. inopinata is a variable, polymorphic species, consisting of a (semi-) continuous morphological cluster, in which both clonal genotypes and sexual haplotypes are nested. Therefore, Limnocythere sappaensis Staplin and L. binoda Huang are considered synonyms of L. inopinata; L. mongolica Daday is a possible synonym; L. sanctipatricii sensu Huang and L. dubiosa sensu Huang from Lake Qinghai are most likely erroneous identifications. Apparently recognisable clones with typical ecologies cannot be allocated a taxonomic rank, as this does not reflect a phylogenetic reality. Such links between recognisable morphologies and typical ecological ranges are useful for palaeoenvironmental reconstructions, but are applicable at a regional scale only.
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    URL: http://dx.doi.org/10.1023/A:1003759125903
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  • 96
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    Environment factors influence in vitro interspecific interactions between A. ochraceus and other maize spoilage fungi, growth and ochratoxin production (1999)
    Springer
    Mycopathologia 146 (1999), S. 43-47 
    Details
    ISSN: 1573-0832
    Keywords: interspecific interactions ; ochratoxin ; Aspergillus ochraceus ; spoilage fungi ; water relations ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The effect of water availability (water activity,aw; 0.995–0.90) and temperature (18–30 °) on in vitro interactions between an ochratoxin producing strain of Aspergillus ochraceus and six other spoilage fungi was assessed in dual culture experiments on a maize meal-based agar medium. Inprimary resource capture of nutrient substrate, A. ochraceus was dominant against many of the interacting species, being able to overgrow and replace A. candidus, and sometimes A. flavus and the Eurotium spp. regardless of aw or temperature. However, with freely available water (0.995 aw) A. alternata and A. niger were dominant, with mutual antagonism between A. ochraceus and A. flavus at 25–30 °C. In the driest conditions tested (0.90 aw) there was also mutual antagonism between A. ochraceus and the two Eurotium spp. Overall, under allconditions tested the Index of Dominance for A. ochraceus was much higher than for other competing species combined suggesting that A. ochraceus wasa good competitive colonist able to replace a numberof other species. However, the growth rate ofA. ochraceus was modified and decreased by the interaction with competitors. Interaction between A. ochraceus and species such as A. alternata (18°C/0.995) and Eurotium spp. (0.995–0.95 and 25–30 °C) resulted in a significant stimulation of ochratoxin production. Theresults are discussed in relation to the effect that environmental factors have on the possible competitiveness of A. ochraceus in the maizegrain ecosystem and the role of ochratoxin in nicheexclusion of competitors.
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    URL: http://dx.doi.org/10.1023/A:1007003316562
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  • 97
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    Dependence of the entomopathogenic fungus, Beauveria bassiana, on high humidity for infection of Rhodnius prolixus (1999)
    Springer
    Mycopathologia 146 (1999), S. 33-41 
    Details
    ISSN: 1573-0832
    Keywords: entomopathogenic hyphomycete ; vector control ; Chagas disease ; Beauveria bassiana ; Rhodnius prolixus ; humidity ; temperature ; incubation time ; mortality
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The impact of relative humidity (RH) on the infective potential of the isolate Bb INRA 297 of Beauveriabassiana (Bals.) Vuillemin (Deuteromycotina: Hyphomycetes) against first in star nymphs of Rhodnius prolixus Stål. (Hemiptera: Reduviidae) was determined. Fungus-treated insects were exposed to RHs ranged from 75 to 100% at 25 °C. Results clearly showed a threshold of humidity at ca. 96% for high and rapid mortality. After initial exposure to increasing periods of 97% (4, 8, 16, 24, 36 and 48 h) and subsequent transfer to constant lower RHs (43, 53,75 and 86%) at a constant 25 °C, an incubation of at least 48 h at 97% RH was necessary to kill all insects. On changing RHs of 97/75% and different regimes of temperature (15/28 °C,20/25 °C, 25/28 °C,and 25/35 °C), at least 72 h of initial exposure at 97% RH for the 15/28 °C regime, 48 h for the 20°/25°C and25/28 °C regimes and 36 h for25/35 °C were needed to kill all insects over a 6-day incubation time. Delayed exposure to favorable moisture condition (97% RH), significantly affected infection for up to a 3-day delay within the various temperature-humidity regimes tested.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007019402490
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  • 98
    Electronic Resource
    Electronic Resource
    Continuous measurements of stress and temperature during testing of a fibre shotcrete pressure plug (1999)
    Springer
    Geotechnical and geological engineering 17 (1999), S. 335-349 
    Details
    ISSN: 1573-1529
    Keywords: underground gas storage ; pressure barrier ; fibre shotcrete ; stress ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract The paper describes an investigation of pressure barriers (plugs) for an underground gas storage facility which were to be constructed from fibre shotcrete. An extensive measurement program on a test plug was carried out to verify the suitability of fibre shotcrete for this purpose. The results of stress and temperature measurements carried out during the construction of the test plug and during cyclic loading of the plug to a water pressure up to 13 MPa are presented. The measurement program provided information on the stress and temperature development inside the plug body during hydration and hardening and also on the residual tensile stresses at the interface between the plug and the rock mass after the end of hydration. Another important output was information on the quality of the plug-rock mass interface, which was critical for a possible leakage. The results obtained during the cyclic loading of the plug revealed uneven stress distribution at the contact and in the adjacent rock mass. It also provided information on the rate of stress redistribution at the contact and inside the rock mass. The results were used to modify the technology of the shotcrete technique to be applied in the final plugs. The gas storage facility using the modified design has been in trial operation since the end of 1998.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008929726458
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  • 99
    Electronic Resource
    Electronic Resource
    Sulfate solubility algorithms for CaSO4–NaCl–H2O and Na2SO4–NaCl–H2O in chlor alkali brine at 25, 65, 75 and 85 ∘C (1999)
    Springer
    Journal of applied electrochemistry 29 (1999), S. 525-528 
    Details
    ISSN: 1572-8838
    Keywords: brine ; chlor-alkali cells ; solubility ; sulfate ions ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026405806916
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  • 100
    Electronic Resource
    Electronic Resource
    Adsorption of Reactive Dye on Chitin (1999)
    Springer
    Environmental monitoring and assessment 59 (1999), S. 111-119 
    Details
    ISSN: 1573-2959
    Keywords: adsorbent concentration ; adsorbent size ; adsorption ; chitin ; pH ; reactive dye ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The adsorption of reactive dye on chitin has been investigated with a view to obtain the design data for batch processing of effluents for dye adsorption. The effect of several factors governing the dye adsorption such as the adsorbent concentration, adsorbent size, temperature and pH have been elicited. Desorption of the dye at different temperatures and pH have also been investigated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006072119624
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