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  • kinetics  (77)
  • RAPD  (64)
  • climate change  (49)
  • Springer  (190)
  • MDPI Publishing
  • 2000-2004  (190)
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  • Springer  (190)
  • MDPI Publishing
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  • 1
    Electronic Resource
    Electronic Resource
    Why Does the Linear Driving Force Model for Adsorption Kinetics Work? (2000)
    Springer
    Adsorption 6 (2000), S. 137-147 
    Details
    ISSN: 1572-8757
    Keywords: adsorption ; kinetics ; linear driving force model ; process design
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The Linear Driving Force (LDF) model for gas adsorption kinetics is frequently and successfully used for analysis of adsorption column dynamic data and for adsorptive process designs because it is simple, analytic, and physically consistent. Yet, there is a substantial difference in the characteristics of isothermal batch uptake curves on adsorbent particles by the LDF and the more rigorous Fickian Diffusion (FD) model. It is demonstrated by using simple model systems that the characteristics of the adsorption kinetics at the single pore or the adsorbent particle level are lost in (a) evaluating overall uptake on a heterogeneous porous solid, (b) calculating breakthrough curves from a packed adsorbent column, and (c) establishing the efficiency of separation by an adsorptive process due to repeated averaging of the base kinetic property. That is why the LDF model works in practice.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008965317983
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  • 2
    Electronic Resource
    Electronic Resource
    Effect of K, Cs and Ba on the kinetics of NH3 synthesis over carbon-based ruthenium catalysts (2000)
    Springer
    Catalysis letters 68 (2000), S. 163-168 
    Details
    ISSN: 1572-879X
    Keywords: ammonia synthesis ; kinetics ; ruthenium catalysts ; promotional effect
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The kinetics of NH3 synthesis over carbon-based ruthenium catalysts promoted with barium or alkali was studied. Both the ammonia partial pressure dependencies of the reaction rates (T = 400°C, p = 63 bar, H2 : N2 = 3 : 1) and the pressure variations of the activity (T = 370°C, p= 4–63 bar, H2 : NN2 = 3 : 1) were found to be different for Ba and for the alkali (K, Cs). Ba–Ru/C proved to be more sensitive to the NH3 content and to the total pressure. The rate of synthesis over the alkali-promoted catalysts is, in turn, much stronger influenced by the ruthenium dispersion. TOFs of NH3 synthesis for the promoted samples at 370°C and 4 bar (Ba 0.085 1/s, Cs 0.05 1/s, K 0.035 1/s) are significantly higher than that for the Ru(0001) basal plane (0.0085 1/s results from the literature data at 370°C, 2 bar). The most active Ru/C samples (Ba or Cs) exceed significantly the fused iron catalyst, especially at high conversions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1019024629261
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  • 3
    Electronic Resource
    Electronic Resource
    Mechanism of the hydrodenitrogenation of o-toluidine and methylcyclohexylamine over NiMo/γ-Al2O3 (2000)
    Springer
    Topics in catalysis 11-12 (2000), S. 327-333 
    Details
    ISSN: 1572-9028
    Keywords: hydrodenitrogenation ; toluidine ; methylcyclohexylamine ; kinetics ; nickel-promoted molybdenum sulphide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The hydrodenitrogenation (HDN) of o-toluidine and its reaction intermediates was studied over a NiMo/γ-Al2O3 catalyst. The kinetics of the HDN of methylcyclohexylamine and of the hydrogenation of cyclohexene were also studied. Hydrogenation of o-toluidine alone produces methylcyclohexene and methylcyclohexane. When a sufficient quantity of cyclohexene is added during the HDN of toluidine, methylcyclohexylamine, the first intermediate in the hydrogenation of toluidine, becomes detectable. Because of its strong adsorption constant and high rate constant for reacting further to methylcyclohexene and methylcyclohexane, methylcyclohexylamine is not observed in the HDN of toluidine. Adding cyclohexene decreases the adsorption of methylcyclohexylamine, thus enabling its detection. The rate and adsorption constants of methylcyclohexylamine and cyclohexene in the HDN of methylcyclohexylamine were calculated by fitting the kinetic data to a Langmuir–Hinshelwood equation. A two-site model was used to describe the surface reactions, with one site for the methylcyclohexylamine reactions and the other for the cyclohexene reaction.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1027208200169
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  • 4
    Electronic Resource
    Electronic Resource
    Static and Kinetic Studies on the Adsorption Behavior of Sulfadiazene (2000)
    Springer
    Adsorption 6 (2000), S. 349-357 
    Details
    ISSN: 1572-8757
    Keywords: sulfadiazene ; adsorption ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract To investigate the nature of interactive forces between sulfadiazene molecules and alumina surface the experiments were performed for the adsorption of sulfadiazene (SD) from its aqueous sulution onto the alumina surfaces at 25 ± 0.2°C and the influence of factors such as increasing concentration of SD (4.0–20.0 × 10−3 mol cm−3), the time required for adsorption equilibrium, pH (2.0–12.0) and temperature (5–45°C) of the adsorption medium, the presence of ions like Cl−, SO2− 4 and PO3− 4 (0.01–0.30 M) and organic solvents (5% v/v) were observed on the course of adsorption of SD. Various adsorption and kinetic parameters such as adsorption coefficient, the rate constants for adsorption and desorption were also evaluated. The results of the above cited studies facilitated to formulate the mechanisms of interaction between SD and alumina surfaces. From application view point the present work may be a potential tool for an effective chromatographic separation of sulfa drugs from industrial effluents.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026517117239
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  • 5
    Electronic Resource
    Electronic Resource
    NO reduction over La2O3 using methanol (2000)
    Springer
    Catalysis letters 64 (2000), S. 65-75 
    Details
    ISSN: 1572-879X
    Keywords: NO reduction ; CH3OH ; La2O3 ; methyl nitrite ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Nitric oxide (NO) reduction by methanol was studied over La2O3 in the presence and absence of oxygen. In the absence of O2, CH3OH reduced NO to both N2O and N2, with selectivity to dinitrogen formation decreasing from around 85% at 623 K to 50–70% at 723 K. With 1% O2 in the feed, rates were 4–8 times higher, but the selectivity to N2 dropped from 50% at 623 K to 10% at 723 K. The specific activities with La2O3 for this reaction were higher than those for other reductants; for example, at 773 K with hydrogen a specific activity of 35 μmol NO/s m2 was obtained whereas that for methanol was 600 μmol NO/s m2. The Arrhenius plots were linear under differential reaction conditions, and the apparent activation energy was consistently near 14 kcal/mol with CH3OH. Linear partial pressure dependencies based on a power rate law were obtained and showed a near‐zero order in CH3OH and a near‐first order in H2. In the absence of O2, a Langmuir–Hinshelwood type model assuming a surface reaction between adsorbed CH3OH and adsorbed NO as the slow step satisfactorily fitted the data, and the model invoking two types of sites provided the best fit and gave thermodynamically consistent rate constants. In the presence of O2 a homogeneous gas‐phase reaction between O2, NO, and CH3OH occurred to yield methyl nitrite. This reaction converted more than 30% of the methanol at 300 K and continued to occur up to temperatures where methanol was fully oxidized. Quantitative kinetic studies of the heterogeneous reaction with O2 present were significantly complicated by this homogeneous reaction.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1019036431195
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  • 6
    Electronic Resource
    Electronic Resource
    Oxidation of dicyclopentadiene catalyzed by palladium(II) acetate and p-benzoquinone in the presence of inorganic acid (2000)
    Springer
    Catalysis letters 69 (2000), S. 103-107 
    Details
    ISSN: 1572-879X
    Keywords: dicyclopentadiene ; Wacker oxidation ; Pd(AcO)2 ; benzoquinone ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The oxidation of dicyclopentadiene catalyzed by palladium(II) acetate and benzoquinone in the presence of perchloric acid was studied. Tricyclodecenone in high selectivity (85–98%) at a conversion of dicyclopentadiene up to 76% was obtained. The kinetic model assumed the significant inhibition complexation between dicyclopentadiene and tricyclodecenone with the catalytic species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1019053402854
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  • 7
    Electronic Resource
    Electronic Resource
    Late-glacial and early-Holocene Trichoptera (Insecta) from Kråkenes Lake, western Norway (2000)
    Springer
    Journal of paleolimnology 23 (2000), S. 49-56 
    Details
    ISSN: 1573-0417
    Keywords: Trichoptera ; caddisflies ; late glacial ; Allerød ; Younger Dryas ; early Holocene ; Kråkenes ; palaeolimnology ; climate change
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences
    Notes: Abstract Fossil Trichoptera (caddisfly) remains have been identified and quantitatively recorded in the late-glacial and early-Holocene sediments from Kråkenes Lake, western Norway. The sediment sequence was deposited between 12,300 and 8850 14C BP, covering the Allerød, Younger Dryas, and early-Holocene periods. The first Trichoptera were recorded at 12,000 14C BP, and during the Allerod a diverse assemblage of Limnephilidae taxa developed in the lake. By about 11,400 14C BP the relatively thermophilous Polycentropus flavomaculatus and Limnephilus rhombicus were present, suggesting that the summer water temperature was at least 17 °C. This temperature fell by 5-8 °C at the start of the Younger Dryas, and the thermophilous taxa were replaced within 20-40 14C yrs by Apatania spp., including the arctic-alpine A. zonella, suggesting a maximum summer water temperature of 10-12 °C. The Trichoptera assemblage was impoverished in numbers and in diversity over the next 200 yrs as the severe conditions of the Younger Dryas developed. As soon as temperatures rose and glacial meltwater and silt input ended about 700 14C yrs later, the resident Apatania assemblage expanded immediately, within 10 yrs. About 130 yrs later, thermophilous taxa replaced Apatania, and a much more diverse assemblage than in the Allerod occupied the varied habitats made available by the development of the Holocene lake ecosystem. The 130 yr delay may have been caused by a gradual temperature increase crossing a critical threshold, or by the time taken for thermophilous taxa to migrate from their Younger Dryas refugia.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008064831048
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  • 8
    Electronic Resource
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    Evidence for mid-Eemian cooling in continental climatic record from Lake Baikal (2000)
    Springer
    Journal of paleolimnology 23 (2000), S. 365-371 
    Details
    ISSN: 1573-0417
    Keywords: Lake Baikal ; diatoms ; biogenic silica ; Eemian ; climate change ; Siberia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences
    Notes: Abstract The discussion on climatic instability observed in Greenland ice cores during the Eemian period (substage 5e) resulted in discovery of a pronounced mid-Eemian cooling event. We report that the mid-Eemian cooling is found for the first time in the biogenic silica climatic record and microfossil abundance record of Lake Baikal. Timing of this event in Lake Baikal correlates well with timing of the European pollen records and marine sedimentary records. The presence of the mid-Eemian cooling signal in the Lake Baikal record suggests a much closer link between Asian climate influenced by strong pressure fields over the vast land masses and the climate-controlling processes in the North Atlantic during interglacial periods, than what was generally believed. Furthermore, the Lake Baikal record suggests that after the mid-Eemian cooling, the climatic conditions returned close to the warmth of the 5e optimum and thus argues that the warm conditions of the last interglacial persisted in Siberia throughout 5e, and did not end with the mid-Eemian cooling as suggested by several published marine records.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008188100542
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  • 9
    Electronic Resource
    Electronic Resource
    Holocene lake sediment records of Arctic hydrology (2000)
    Springer
    Journal of paleolimnology 24 (2000), S. 1-13 
    Details
    ISSN: 1573-0417
    Keywords: Arctic ; Holocene ; paleohydrology ; paleolimnology ; climate change
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences
    Notes: Abstract Although paleoclimatic research in the Arctic has most often focused on variations in temperature, the Arctic has also experienced changes in hydrologic balance. Changes in Arctic precipitation and evaporation rates affects soils, permafrost, lakes, wetlands, rivers, ice and vegetation. Changes in Arctic soils, permafrost, runoff, and vegetation can influence global climate by changing atmospheric methane and carbon dioxide concentrations, thermohaline circulation, and high latitude albedo. Documenting past variations in Arctic hydrological conditions is important for understanding Arctic climate and the potential response and role of the Arctic in regards to future climate change. Methods for reconstructing past changes in Arctic hydrology from the stratigraphic, isotopic, geochemical and fossil records of lake sediments are being developed, refined and applied in a number of regions. These records suggest that hydrological variations in the Arctic have been regionally asynchronous, reflecting the impacts of different forcing factors including orbitally controlled insolation changes, changes in geography related to coastal emergence, ocean currents, sea ice extent, and atmospheric circulation. Despite considerable progress, much work remains to be done on the development of paleohydrological proxies and their application to the Arctic.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008100714795
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  • 10
    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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  • 11
    Electronic Resource
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    A first estimate of organic carbon storage in Holocene lake sediments in Alberta, Canada (2000)
    Springer
    Journal of paleolimnology 24 (2000), S. 395-400 
    Details
    ISSN: 1573-0417
    Keywords: carbon storage ; lake sediment ; Holocene ; Canada ; climate change ; organic matter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences
    Notes: Abstract This paper reports a first estimate of the Holocene lake sediment carbon pool in Alberta, Canada. The organic matter content of lake sediment does not appear to depend strongly on lake size or other limnological parameters, allowing a simple first estimate in which we assume all Alberta lake sediment to have the same organic matter content. Alberta lake sediments sequester about 15 g C m-2 yr-1, for a provincial total of 0.23 Tg C yr-1, or 2.3 Pg C over the Holocene. Alberta lakes may represent as much as 1/1700 of total global, annual permanent carbon sequestration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008103605817
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  • 12
    Electronic Resource
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    Using a Crop/Soil Simulation Model and GIS Techniques to Assess Methane Emissions from Rice Fields in Asia. III. Databases (2000)
    Springer
    Nutrient cycling in agroecosystems 58 (2000), S. 179-199 
    Details
    ISSN: 1573-0867
    Keywords: climate change ; databases ; GIS ; methane ; rice ; soils ; weather
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract As part of a series of papers describing the use of a simulation model to extrapolate experimental measurements of methane (CH4) emissions from rice fields in Asia and to evaluate the large-scale effect of various mitigation strategies, the collation and derivation of the spatial databases used are described. Daily weather data, including solar radiation, minimum and maximum temperatures, and rainfall were collated from 46 weather stations from the five countries in the study, namely China, India, Indonesia, Philippines, and Thailand. Quantitative soil data relevant to the input requirements of the model were derived by combining data from the World Inventory of Soil Emissions (WISE) database, the ISIS database, and the FAO Digital Soil Map of the World (FAO-DSMW). These data included soil pH; organic carbon content; sand, silt, and clay fractions; and iron content for top and subsoil layers, and average values of bulk density and available water capacity for the whole profile. Data on the areas allocated to irrigated, rainfed, upland, and deepwater rice at the province or district level were derived from the Huke & Huke (1997) database developed at IRRI. Using a geographical information system (GIS), a series of georeferenced data sets on climate, soils, and land use were derived for each country, at the province or district level. A summary of the soil-related derived databases is presented and their applicationn for use in global change modeling discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009898720354
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  • 13
    Electronic Resource
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    Molecular Cloning and Characterization of a Microsatellite Locus Found in an RAPD Marker of a Spider Mite, Panonychus Citri (Acari: Tetranychidae) (2000)
    Springer
    Experimental and applied acarology 24 (2000), S. 385-395 
    Details
    ISSN: 1572-9702
    Keywords: Panonychus citri ; spider mite ; microsatellite ; RAPD ; PCR ; DNA polymorphism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Genetic markers were searched using PCR with 40 kinds of decanucleotide primers to investigate DNA polymorphism in Panonychuscitri. A region consisting of a variable number of CT tandem repeats (microsatellite) was found in a fragment amplified with the OPB10 primer. The microsatellite differed in size by ca. 100 bp among several P. citri populations screened and was derived from at least seven alleles. This region was characteristic of P. mori and P. osmanthi, but was lacking in P. ulmi. The flanking regions were highly conserved among these species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006405325992
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  • 14
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    Parallel microgeographic patterns of genetic diversity and divergence revealed by allozyme, RAPD, and microsatellites in Triticum dicoccoides at Ammiad, Israel (2000)
    Springer
    Conservation genetics 1 (2000), S. 191-207 
    Details
    ISSN: 1572-9737
    Keywords: allozyme ; microgeographic divergence ; microsatellite ; natural selection ; RAPD ; Triticum dicoccoides ; wild emmer wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The levels of genetic diversity were compared by means of 35 allozyme, 60 RAPD, and 25 microsatellite (SSR) markers for 75–175 individuals of tetraploid wild emmer wheat (Triticum dicoccoides) collected in 1993 from a microgeographic microsite, Ammiad, north of the Sea of Galilee, Israel. This microsite included four major habitats, which showed highly significant differentiation in ecological factors, in particular with respect to rock cover, proximity and height, and surface soil moisture in the early growing season of T. dicoccoides. Higher within-subpopulation genetic diversity was found in the primarily non-coding DNA regions (RAPD and SSR) rather than in the protein-coding (allozymes) regions. However, much larger gene differentiation (G ST) among the subpopulations was observed in the protein-coding allozymes than in the RAPDs and SSRs. Larger genetic distance was found at SSR loci, followed by allozyme and RAPD loci. The subpopulations in drier habitats tend to have higher allozyme, RAPD and SSR diversities (He), the relatively wet Karst subpopulation showed only about half He of the other relatively drier habitats. The subpopulations with larger difference of soil moisture between habitats tend to show larger genetic distances at allozyme, RAPD and SSR loci. These results suggest that climatic selection through aridity stress may be an important factor acting on both structural protein-coding and presumably partly regulatory non-coding DNA regions, resulting in microscale adaptive patterns, although hitchhiking and random drift may also intervene. These results have profound implications for genetic conservation both in situ and ex situ.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1011545403198
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  • 15
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    Conservation genetics of an endangered rainforest tree (Fontainea oraria – Euphorbiaceae) and implications for closely related species (2000)
    Springer
    Conservation genetics 1 (2000), S. 217-229 
    Details
    ISSN: 1572-9737
    Keywords: Australia ; conservation strategy ; cpDNA ; Euphorbiaceae ; Fontainea ; nrDNA ; RAPD
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Four new eastern Australian Fontainea species have beenrecently described and all have a limited distribution. F.oraria is the rarest, being restricted to 10 adult individualswithin a single site in regrowth littoral rainforest. In order todevelop adequate management strategies, this study was aimed atsurveying the genetic variability remaining within the species by usingRAPD analysis. To assist with the correct interpretation of the results,a matching study was conducted on four populations of the closelyrelated F. australis. Similar amounts of within-populationgenetic diversity were recorded for both species. The RAPD-based studysuggested that adult plants are contributing unevenly to successivegenerations. RAPD analysis also recognised a close evolutionaryrelationship between F. oraria and F. australis.Sequencing of cpDNA (trnL-F) and nrDNA (ITS2) regions,confirmed recent divergence and possibly some historical reticulationbetween these two species and two other members of the genus. Ofparticular interest was the recognition that one of the F.australis populations (Limpinwood) represented a novel genotypiccombination in need of conservation attention. The implications of theRAPD and sequencing results are discussed in reference to theirinfluence upon the development of adequate conservation strategies forall important conservation units.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1011549604106
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  • 16
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    Evidence of apomixis in hemisexual dogroses, Rosa section Caninae (2000)
    Springer
    Sexual plant reproduction 12 (2000), S. 353-359 
    Details
    ISSN: 1432-2145
    Keywords: Key words Rosa sect Caninae ; Heterogamy ; Apomixis ; RAPD ; Pollen viability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  All members of Rosa section Caninae, dogroses are polyploid and characterized by their unbalanced meiosis, which in most cases leads to a pronounced morphological influence from the maternal parent. In a previous investigation on a pair of reciprocal crosses between two species in this section, Rosa dumalis and R. rubiginosa (2n=35), nine offspring plants (approximately 10%) did not receive any of the 21 RAPD markers present in the respective pollen parent. This was interpreted as a possible occurrence of apomixis. These nine plants have now been subjected to a further study with additional markers. Thirteen new RAPD markers showed the same result as in the previous investigation: none of the nine plants inherited any of the pollen donor markers. The reproducibility of the RAPD markers was checked by mixing DNA samples to obtain a series of artificial hybrids between the two parent plants. Twelve RAPD markers gave the expected result, whereas one marker appeared only 50% of the time. In addition, pollen viability, mean number of seeds per hip, mean seed weight, and mean weight of fruit flesh per hip have been studied on the four progeny groups: R. dumalis×R. rubiginosa plants which received pollen donor markers (PM plants), R. dumalis×R. rubiginosa plants which did not receive any pollen donor markers (NPM plants), R. rubiginosa×R. dumalis PM plants and R. rubiginosa×R. dumalis NPM plants. A canonical discriminant analysis based on these four reproductive characters separated the four progeny groups. There were significant differences between the two PM groups in all investigated characters, and also between the PM and the NPM groups in pollen viability. The result from the RAPD markers together with the differences in pollen viability between the PM and NPM progeny groups is taken as an indication that apomixis occurs within the Caninae section.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004970000028
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  • 17
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    Citrus phylogeny and genetic origin of important species as investigated by molecular markers (2000)
    Springer
    Theoretical and applied genetics 100 (2000), S. 1155-1166 
    Details
    ISSN: 1432-2242
    Keywords: Key words Citrus ; RAPD ; SCAR ; cpDNA ; Phylogeny ; Origin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Citrus phylogeny was investigated using RAPD, SCAR and cpDNA markers. The genotypes analyzed included 36 accessions belonging to Citrus together with 1 accession from each of the related genera Poncirus, Fortunella, Microcitrus and Eremocitrus. Phylogenetic analysis with 262 RAPDs and 14 SCARs indicated that Fortunella is phylogenetically close to Citrus while the other three related genera are distant from Citrus and from each other. Within Citrus, the separation into two subgenera, Citrus and Papeda, designated by Swingle, was clearly observed except for C. celebica and C. indica. Almost all the accessions belonging to subgenus Citrus fell into three clusters, each including 1 genotype that was considered to be a true species. Different phylogenetic relationships were revealed with cpDNA data. Citrus genotypes were separated into subgenera Archicitrus and Metacitrus, as proposed by Tanaka, while the division of subgenera Citrus and Papeda disappeared. C. medica and C. indica were quite distant from other citrus as well from related genera. C. ichangensis appeared to be the ancestor of the mandarin cluster, including C. tachibana. Lemon and Palestine sweet lime were clustered into the Pummelo cluster led by C. latipes. C. aurantifolia was located in the Micrantha cluster. Furthermore, genetic origin was studied on 17 cultivated citrus genotypes by the same molecular markers, and a hybrid origin was hypothesized for all the tested genotypes. The assumptions are discussed with respect to previous studies; similar results were obtained for the origin of orange and grapefruit. Hybrids of citron and sour orange were assumed for lemon, Palestine sweet lime, bergamot and Volkamer lemon, while a citron × mandarin hybrid was assumed for Rangpur lime and Rough lemon. For Mexican lime our molecular data indicated C. micrantha to be the female parent and C. medica as the male one.
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    URL: http://dx.doi.org/10.1007/s001220051419
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    An assessment of genetic relationships within the genus Digitalis based on PCR-generated RAPD markers (2000)
    Springer
    Theoretical and applied genetics 100 (2000), S. 1209-1216 
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    ISSN: 1432-2242
    Keywords: Key words Digitalis spp. ; AMOVA ; Genetic relationships ; RAPD ; Scrophulariaceae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  RAPD markers were used to study inter-specific variation among six species of the genus Digitalis: D. obscura, D. lanata, D. grandiflora, D. purpurea, D. thapsi and D. dubia, and the hybrid D. excelsior (D. purpurea×D. grandiflora). A total of 91 highly reproducible bands amplified with four arbitrarily chosen decamer primers were obtained. Homology of the co-emigrating RAPD markers was tested by blot hybridisation and sequencing of selected bands. The application of a range of statistical approaches for RAPD data analysis, including distance and parsimony methods, family clustering and the analysis of molecular variance (AMOVA), indicated that these molecular markers were taxonomically informative in Digitalis. The species relationships revealed were fully consistent with those previously obtained using morphological affinities. The hybrid D. excelsior seems to have stronger affinity to the section Digitalis than to Grandiflorae. This is the first known report of the application of RAPD markers for the study of genetic relationships among species of the genus Digitalis.
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    URL: http://dx.doi.org/10.1007/s001220051426
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    Genetic diversity of Poa annua in western Oregon grass seed crops (2000)
    Springer
    Theoretical and applied genetics 101 (2000), S. 70-79 
    Details
    ISSN: 1432-2242
    Keywords: Key words Poa annua L. ; Genetic diversity ; RAPD ; Turfgrass weeds ; Selection pressure ; Analysis of molecular variance ; AMOVA ; POPGENE
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The genetic diversity of Poa annua L.populations collected from western Oregon grass-seed fields was surveyed using 18 randomly amplified polymorphic DNA (RAPD) markers. Markers from 1357 individual plants from 47 populations collected at three sampling dates (fall, winter, and spring) for 16 sites were used to measure genetic diversity within and among populations. Site histories varied from low to high herbicide selection pressure, and some sites were subdivided by 3 years of differing post-harvest residue management. Gene diversity statistics, simple frequency of haplotype occurrence, and analysis of molecular variance (AMOVA) revealed the presence of significant variability in P. annua among sites, among collection dates within sites, and within collection dates. Nei gene-diversity statistics and population-differentiation parameters indicated that P. annua populations were highly diverse. Mean Nei gene diversity (h) for all 47 populations was 0.241 and total diversity (HT) was 0.245. A greater proportion of this diversity, however, was within (HS=0.209) rather than among (GST=0.146) populations. When populations were grouped by season of collection, within-group diversity was HS=0.241, while among-group diversity was GST=0.017. When populations were grouped by site, within-group diversity was HS=0.224, while among-group diversity was GST=0.087. The diversity among populations within season for fall, winter, and spring collections was GST=0.121, 0.142, and 0.133, respectively. Populations collected from fields with histories of high herbicide selection pressure showed low differentiation among collection dates, with GST as low as 0.016, whereas those collected from fields with low herbicide selection pressure showed greater differentiation among collection dates, with GST as high as 0.125. At high selection-pressure sites, populations were also lower in gene diversity (as low as h=0.155), while at low selection-pressure sites there was higher gene diversity (as high as h=0.286). The site to site variability was greater for the high selection-pressure sites (GST=0.107 or 69% of the total among-population variance), while the season of germination variability was greater at sites of low herbicide-selection pressure (GST=0.067, or 70% of the total among-population variance). High initial diversity coupled with a long-term re-supply of genotypes from the seed bank must have been factors in maintaining the genetic diversity of this weed despite the intensive use of herbicides. Knowledge of the genetic diversity of Willamette Valley P. annua should help in formulating more effective strategies for managing this weed.
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    URL: http://dx.doi.org/10.1007/s001220051451
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    A computerised algorithm for selecting a subset of multiplex molecular markers and optimising linkage map construction (2000)
    Springer
    Theoretical and applied genetics 101 (2000), S. 90-94 
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    ISSN: 1432-2242
    Keywords: Key words Molecular map ; AFLP ; RAPD ; Optimisation algorithm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  A computer algorithm is presented which allows selection of a subset of multiplex markers based on the minimisation of an optimality criterion for a genetic linkage map. It could be applied for choosing a subset of primers (e.g. RAPD, IMA or AFLP), each of which provides several unevenly spaced genetic markers. The goal is to achieve a saturated map of evenly spaced markers, using as few primers as possible to minimise cost and labour. Minimising the average map distance between markers is trivial, but simply leads to selection of those primers which provide the greatest number of markers. However, minimising the standard deviation of interval length ensures that weight is given both to the number of markers and to the evenness of their distribution on the linkage map. This criterion was found empirically to give a result fairly close to the optimum. A stepwise-like selection procedure is therefore implemented, which stops when the optimality criterion does not decrease any more. An example is given of a molecular map of perennial ryegrass with 463 markers obtained from 17 AFLP primers. It is demonstrated that this can be safely reduced to a 175 marker map with only 6 primers. Genetic diversity studies may also benefit from using such a subset of less-redundant markers in genetic distance estimation.
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    Linkage mapping and QTL analysis in coconut (Cocos nucifera L.) (2000)
    Springer
    Theoretical and applied genetics 101 (2000), S. 292-300 
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    ISSN: 1432-2242
    Keywords: Key words AFLP ; DNA markers ; Early germination ; ISSR ; ISTR ; RAPD
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Different DNA marker types were used to construct linkage maps in coconut (Cocos nucifera L.; 2n = 32) for the two parents of the cross Malayan Yellow Dwarf (MYD) × Laguna Tall (LAGT). A total of 382 markers was sufficient to generate 16 linkage groups for each parent. The total genome length corresponded to 2226 cM for the LAGT map and 1266 cM for the MYD map with 4–32 markers per linkage group. Common markers allowed the association of 9 linkage groups for the two parents MYD and LAGT. QTL analysis for the trait early germination identified six loci. These QTLs correlate with early flowering and yield, representing characters which are important in coconut breeding. The co-segregation of markers with these QTLs provides the first opportunity for marker-assisted selection in coconut breeding programmes.
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    URL: http://dx.doi.org/10.1007/s001220051482
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    Host effect on genetic variation of Marssonina brunnea pathogenic to poplars (2000)
    Springer
    Theoretical and applied genetics 100 (2000), S. 614-620 
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    ISSN: 1432-2242
    Keywords: Key words Aigeiros ; Leuce ; Marssonina brunnea ; Poplar ; RAPD ; Tacamahaca
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  A broad collection was made for 42 isolates of Marssonina brunnea affecting poplar trees from three different sections (Leuce, Aigeiros and Tacamahaca) within the same Populus genus in China. Genetic diversity among these isolates was analyzed for morphological traits, cultural features, pathogenicity, hyphal anastomosis and randomly amplified polymorphic DNA markers (RAPDs). No significant difference was found in conidial morphological features, such as size, shape and septum location. Yet, considerable differences occur in other characteristics, which leads to the classification of the 42 isolates into two distinct groups, M. brunnea f.sp. monogermtubi and M. brunnea f.sp. multigermtubi. Isolates of M. brunnea f.sp. monogermtubi, derived from section Leuce, germinate only one germ tube, grow fast, produce dark-reddish conidiosorus clusters on the PDA medium, and are highly pathogenic to Populus tomentosa of section Leuce. By contrast, isolates of M. brunnea f.sp. multigermtubi, derived from sections Aigeiros and Tacamahaca, germinate 1–5 germ tubes, grow slowly, produce yellow-greenish conidiosorus clusters on PDA medium, and are pathogenic to Populus ×euramericana cv I-45 and Populus canadensis of section Aigeiros. DNA amplification using 11 RAPD primers generate 78 polymorphic bands among isolates. Cluster analyses based on RAPD markers broadly support such a classification by phenotypes, but provide a new insight into the possible origins of M. brunnea. It is proposed that the pathogen co-evolves with the poplars of section Leuce and has been subsequently distributed to the poplars of sections Aigeiros and Tacamahaca. An isolate from Populus adenopoda of section Leuce is placed in the third group, which is most likely a transmission type from M. brunnea f.sp. monogermtubi to M. brunnea f.sp. multigermtubi.
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    Development of SCAR markers linked to the gene Or5 conferring resistance to broomrape (Orobanche cumana Wallr.) in sunflower (2000)
    Springer
    Theoretical and applied genetics 100 (2000), S. 625-632 
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    ISSN: 1432-2242
    Keywords: Key words SCAR ; RAPD ; Bulked segregant analysis ; Marker-assisted selection ; Orobanche cumana ; Helianthus annuus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  A consensus molecular linkage map of 61.9 cM containing the Or5 gene, which confers resistance to race E of broomrape orobanche cumana, five SCAR markers (three dominant, two codominant) and one RAPD marker were identified based on segregation data scored from two F2 populations of susceptible×resistant sunflower line crosses. Bulked segregant analysis was carried out to generate the five SCAR markers, while the single RAPD marker in the group was identified from 61 segregating RAPD markers that were directly screened on one of the two F2 populations. The five SCAR markers, RTS05, RTS28, RTS40, RTS29 and RTS41, were significantly (LOD≥4.0) linked to the Or5 gene and mapped separately at 5.6, 13.6, 14.1, 21.4 and 39.4 cM from the Or5 locus on one side, while the RAPD marker, UBC120_660, was found at 22.5 cM (LOD=1.4) on the opposite side. These markers should facilitate the efficient transfer of the resistance gene among sunflower breeding lines. As the first report on molecular markers linked to a broomrape resistance gene, the present work provides a starting point to study other genes and to examine the hypothesis of the clustering of broomrape resistance genes in sunflower.
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    URL: http://dx.doi.org/10.1007/s001220050083
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    Genetic analysis of temperature-sensitive male sterilty in rice (2000)
    Springer
    Theoretical and applied genetics 100 (2000), S. 794-801 
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    ISSN: 1432-2242
    Keywords: Key words TGMS ; RAPD ; AFLP ; Microsatellites ; STS ; Marker-assisted selection ; Bulked seg analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The present study of genetic analysis is an attempt to precisely characterize diverse temperature-sensitive genic male-sterile (TGMS) lines so as to explore the possibilities of utilizing the most promising in large-scale hybrid seed production. Genetical studies revealed that the TGMS segregants derived from crosses involving TGMS lines ID24 and SA2 expressed differential fertility levels at low-temperature conditions. A majority of these progenies expressed transgressive segregation towards either sterility of fertility, causing instability of sterility and low reversibilty of fertility which may be due to large numbers of single-locus QTLs and their epistatic interactions. We identified two putative genes imparting temperature-sensitive male sterility after observing crosses involving diverse TGMS sources. To identify suitable molecular markers closely linked to the trait we used RAPD, AFLP and microsatellites which generated polymorphism through bulked segregant analysis. AFLP analysis using a smaller genome kit resulted in enormous polymorphism, out of which the combination EAA/MCAG amplified a 330-bp fragment, which closely segregated with the gene at a distance of 5.3 cM. This fragment was eluted for cloning and from the sequence a STS primer (TS200) was developed which produced a dominant polymorphism specific to TGMS. The microsatellite RM257, located earlier on chromosome 9, was linked with the TGMS trait in SA2 at a distance of 6.2 cM. RM257 produced a codominant polymorphism with 145-bp (sterile) and 132-bp (fertile) products. Both individually and collectively, the markers TS200 and RM257 located on either side of the TGMS locus are very useful for marker-assisted selection.
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    Development of markers linked to Diuraphisnoxia resistance in wheat using a novel PCR-RFLP approach (2000)
    Springer
    Theoretical and applied genetics 100 (2000), S. 965-970 
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    ISSN: 1432-2242
    Keywords: Key words Russian wheat aphid ; Near-isogenic lines ; Restriction digests ; RAPD ; SCAR
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstracts  Through random amplified polymorphic DNA (RAPD) analysis we identified a putative marker linked to the Dn5 resistance gene. This marker was converted to a more reliable sequence-characterised-amplified regions (SCAR) marker. The initial SCAR marker amplified the correct amplification product but failed to discern between the susceptible and resistant individuals. Hence, it was utilised to sequence the internal fragment. All nested primers designed from the internal sequences were also unable to produce any polymorphism between the susceptible and resistant cultivars. Restriction digests were then performed on these fragments, and the restriction enzyme EcoRI was able to discern between the susceptible and resistant F2 individuals of the Dn5 population. This granted one marker amplified with the internal SCAR primer set OPF141083 the ability to differentiate between parental individuals carrying the Dn5 genes. This marker was tested in a segregating F2 population carrying the Dn5 resistance gene and proved able to differentiate between the segregating individuals. This marker may prove useful in marker assisted selection (MAS), although performing restriction digests may hamper the throughput of a high number of samples.
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    URL: http://dx.doi.org/10.1007/s001220051377
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    A genetic map of Maritime pine based on AFLP, RAPD and protein markers (2000)
    Springer
    Theoretical and applied genetics 100 (2000), S. 39-48 
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    ISSN: 1432-2242
    Keywords: Key words Pinus pinaster ; AFLP ; RAPD ; Protein ; Linkage map ; QTL
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  TheAFLP (amplified fragment length polymorphism) technique was adapted to carry out genetic analysis in maritime pine, a species characterized by a large genome size (24 pg/C). A genetic linkage map was constructed for one F1 individual based on 239 AFLP and 127 RAPD (randomly amplified polymorphic DNA) markers. Markers were scored on megagametophytes (1n) from 200 germinated F2 seedlings. Polymorphism rate, labour time and cost of both AFLP and RAPD techniques were compared. The AFLP technique was found to be twice as fast and three-times less costly per marker than the RAPD technique. Thirteen linkage groups were identified with a LOD score ≥6 covering 1873 cM, which provided 93.4% of genome coverage. Proteins were extracted from needles (2n) of the F2 progeny and revealed by 2-DE (two-dimensional electrophoresis). Thirty one segregating proteins were mapped using a QTL detection strategy based on the quantification of protein accumulation. Two framework maps of the same F1 individual are now available. The first map (Plomion et al. 1996) uses RAPD markers and the second map, presented in this study, uses mostly AFLP markers. Although the total genetic length of both maps was almost identical, differences among homologous groups were observed.
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    RAPD linkage mapping of the shell thickness locus in oil palm (Elaeis guineensis Jacq.) (2000)
    Springer
    Theoretical and applied genetics 100 (2000), S. 63-70 
    Details
    ISSN: 1432-2242
    Keywords: Key words Elaeis guineensis ; RAPD ; Pseudo-testcross ; Genetic linkage map ; bulked segregant analysis ; Shell thickness
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Shell thickness is an important trait in oil palm breeding programs and is the basis for the classification of the varieties of oil palm into the types dura, tenera and pisifera. This trait seems to be controlled by a single locus, with two alleles (sh + and sh −) showing codominant expression. Two single-tree linkage maps were constructed for a maternal tenera (sh + sh −) palm and for a paternal pisifera (sh − sh −) palm using the pseudo-testcross mapping strategy in combination with RAPD markers through the analysis of an F1 tenera×pisifera progeny. A total of 308 arbitrary primers were screened in a sample of eight F1 plants and 121 markers were detected in a testcross configuration. An average of 1.66 polymorphic marker per selected primer were identified in this cross. At LOD 5.0 (with some few exceptions) and θ=0.25 the maternal tenera map included a total of 48 markers distributed in 12 linkage groups or pairs of markers (449.3 cM) while the paternal pisifera map included 42 markers distributed in 15 linkage groups or pairs of markers (399.7 cM). We used RAPD and bulked segregant analysis (BSA) to identify markers more tightly linked to the sh + locus. A total of 174 new primers not previously used in the linkage analysis were screened using bulks of DNA extracted from plants selected for the contrasting shell-thickness phenotypes. Two RAPD markers (R11–1282 and T19–1046) were identified to be linked on both sides of the sh + locus on linkage group 4. The estimated map distances from sh + to R11–1282 and to T19–1046 were 17.5 cM and 23.9 cM, respectively. The results demonstrate the usefulness of RAPD markers and the pseudo-testcross mapping strategy for developing genetic linkage information, and constitute an important step towards early marker-assisted selection for shell thickness in oil palm.
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    Identification and molecular mapping of loci controlling fruit ripening time in tomato (2000)
    Springer
    Theoretical and applied genetics 100 (2000), S. 249-255 
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    ISSN: 1432-2242
    Keywords: Key words QTL ; Earliness ; CAP ; RAPD ; Lycopersicon esculentum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Using RAPD marker analysis, two quantitative trait loci (QTLs) associated with earliness due to reduced fruit-ripening time (days from anthesis to ripening = DTR) were identified and mapped in an F2 population derived from a cross between Lycopersicon esculentum’E6203’ (normal ripening) and Lycopersicon esculentum’Early Cherry’ (early ripening). One QTL, on chromosome 5, was associated with a reduction in both ripening time (5 days) and fruit weight (29.3%) and explained 15.8 and 13% of the total phenotypic variation for DTR and fruit weight, respectively. The other QTL, on chromosome 12, was primarily associated with a reduction only in ripening time (7 days) and explained 12.3% of the total phenotypic variation for DTR. The gene action at this QTL was found to be partially dominant (d/a=0.41). Together, these two QTLs explained 25.1% of the total phenotypic variation for DTR. Additionally, two QTLs associated with fruit weight were identified in the same F2 population and mapped to chromosomes 4 and 6, respectively. Together, these two QTLs explained 30.9% of the total phenotypc variation for fruit weight. For all QTLs, the ’Early Cherry’ alleles caused reductions in both ripening time and fruit weight. The polymorphic band for the most significant RAPD marker (OPAB-06), linked to the reduced ripening time QTL on chromosome 12, was converted to a cleaved amplified polymorphism (CAP) assay for marker-aided selection and further introgression of early ripening time (DTR) into cultivated tomato.
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    URL: http://dx.doi.org/10.1007/s001220050033
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    Application of AFLP, RAPD and ISSR markers to genetic mapping of European and Japanese larch (2000)
    Springer
    Theoretical and applied genetics 100 (2000), S. 299-307 
    Details
    ISSN: 1432-2242
    Keywords: Keywords Larix ; Linkage map ; RAPD ; AFLP ; ISSR ; Genetic mapping
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Genetic linkage maps have been increasingly developed for a wide variety of plants, using segregating populations such as F2s or backcrosses between inbred lines. These pedigrees are rarely available in outbred species like forest trees which have long generation times. Thus genetic mapping studies have to use peculiar pedigrees and markers in appropriate configurations. We constructed single-tree genetic linkage maps of European larch (Larix decidua Mill.) and Japanese larch [Larix kaempferi (Lamb.) Carr.] using segregation data from 112 progeny individuals of an hybrid family. A total of 266 markers (114 AFLP, 149 RAPD and 3 ISSR loci) showing a testcross configuration, i.e.heterozygous in one parent and null in the other parent, were grouped at LOD 4.0, θ=0.3. The maternal parent map (L. decidua)consisted of 117 markers partitioned within 17 linkage groups (1152 cM) and the paternal parent map (L. kaempferi) had 125 markers assembled into 21 linkage groups (1206 cM). The map distance covered by markers was determined by adding a 34.7-cM independence distance at the end of each group and unlinked marker. It reached 2537 cM and 2997 cM respectively for European larch and Japanese larch, and represented respectively a 79.6% and 80.8% coverage of the overall genome. A few 3:1 segregating markers were used to identify homologous linkage groups between the European larch and the Japanese larch genetic maps. The PCR-based molecular markers allowed the construction of genetic maps, thus ensuring a good coverage of the larch genome for further QTL detection and mapping studies.
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    URL: http://dx.doi.org/10.1007/s001220050039
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    Comparison of multivariate methods for the analysis of genetic resources and adaptation in Phytolacca dodecandra using RAPD (2000)
    Springer
    Theoretical and applied genetics 101 (2000), S. 1145-1154 
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    ISSN: 1432-2242
    Keywords: Keywords Altitude differentiation ; Environmental selection ; Phytolacca dodecandra ; RAPD
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The extent of genetic differentiation among 17 Ethiopian populations (249 individuals) of Phytolacca dodecandra (Endod) sampled along altitudinal gradients that varied from 1600 to 3000 m was investigated using random amplified polymorphic DNA (RAPD). The populations were classified into three altitude groups: lowland (1600–2100 m), central-highland (2101–2500 m) and highland (2500–3000 m). Seventy polymorphic loci scored from 12 RAPD primers, singly or in combination with ecogeographical variables (altitude, longitude, latitude, temperature and rainfall), were used for principal component, discriminant, correlation, and stepwise multiple regression analyses. Principal component analysis (PCA) clearly differentiated lowland and the central-highland populations from those of the highlands independent of their geographical regions. Canonical discriminant analysis separated the lowland plants from those of the highlands with the central-highland plants being intermediate. Classificatory discriminant analysis corrected classification of 92.8% of the 249 plants into their respective three altitude groups. Multiple regression analysis identified a strong association between some RAPDs and altitude, temperature and rainfall, while the variation in most RAPDs was explained by combinations of the different ecogeographical variables. It is hypothesised that the different altitude groups may be (1) chemical and/or physiological ecotypes produced as a result of complex interactions of altitude with climatic and/or edaphic factors, or (2) different in ploidy levels. The significant correlations obtained between population means from some RAPDs and altitude and temperature as well as the strong association of some RAPDs with the ecogeographical variables in the multiple regression analysis suggest that part of the RAPD polymorphism could be adaptive, and responsive to environmental selection.
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    URL: http://dx.doi.org/10.1007/s001220051591
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    Phylogenetic relationships and differentiation among and within populations of Chaenomeles Lindl. (Rosaceae) estimated with RAPDs and isozymes (2000)
    Springer
    Theoretical and applied genetics 101 (2000), S. 554-563 
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    ISSN: 1432-2242
    Keywords: Key words Gene diversity ; Isozyme ; Non-neutrality ; RAPD ; Rosaceae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  RAPD and isozyme analyses based on numerous markers have been used for the first time to investigate patterns of phenetic and genetic differentiation among and within nine wild populations of the genus Chaenomeles represented by the species C. japonica, C. speciosa, C. cathayensis and C. thibetica. Highly significant correlations were found between the two different marker systems for both phenetic distances and gene diversity estimates. In agreement with previous studies on cultivated Chaenomeles material, C. japonica was clearly differentiated from C. speciosa and C. cathayensis. The recently recognised species C. thibetica appeared to be rather closely related to C. cathayensis. Populations of C. japonica and C. speciosa were considerably more diverse than populations of C. cathayensis and C. thibetica. Correspondingly, most of the total variability could be attributed to the within-population differentiation in the case of C. japonica and C. speciosa, and to the between-population differentiation in the case of C. cathayensis. Differences in mating systems among the species can be suggested as a possible explanation of the results. A discordant pattern was found between RAPDs and isozymes in the analyses of population structure within C. japonica. This may be explained by a higher proportion of non-neutral markers for isozymes than for RAPDs. This finding also shows the importance of using multiple molecular marker systems in studies of population structure.
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    URL: http://dx.doi.org/10.1007/s001220051515
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    Hot spots of DNA instability revealed through the study of somaclonal variation in rye (2000)
    Springer
    Theoretical and applied genetics 100 (2000), S. 506-511 
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    ISSN: 1432-2242
    Keywords: Key words Rye ; DNA instability ; Hypervariable sequences ; Somaclonal variation ; RAPD
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  RAPD analysis was performed to assess DNA variation among rye plants regenerated from immature embryos and inflorescences. From the studied plants, 40% showed at least one variation, and the number of mutations per plant was quite high, ranging from 1 up to 12. On some occasions (2.9% of the scored bands) the modified band was observed in only one plant or in several but originated from the same callus (variable band). In other cases (5.25%) the same band varied in several plants obtained from different calli. We call these hypervariable bands and they could vary between plants belonging to different cultivars and/or with different origins, inflorescences or embryos. Thus, they must originate through independent mutational events. We assume that these bands represent hypervariable regions of the rye genome and so detect hot spots of DNA instability. Some of these bands proved to be unique sequences, others were present in a low copy number while the remaining ones were moderately or highly repetitive.
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    Design of grapevine (Vitis vinifera L.) cultivar-specific SCAR primers for PCR fingerprinting (2000)
    Springer
    Theoretical and applied genetics 101 (2000), S. 1194-1201 
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    ISSN: 1432-2242
    Keywords: Key words ’Folle blanche’ ; Hybridization ; RAPD ; SCAR ; Sequence-specific primer pair ; Vitis vinifera L
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Among 34 grapevine cultivars (Vitis vinifera L.), eight putative genotype-specific RAPD markers, from ’Albariño’, ’Caíño blanco’, ’Chardonnay’, ’Folle blanche’, ’Grenache blanc’, ’Malvasía Sitges’, ’Torrontés’ and ’Treixadura’ respectively, were selected to transform into SCAR markers. Of these, seven markers were cloned and then five which showed a positive specific hybridization signal were sequenced. For these five markers, 30 sequence-specific primers ranging from 14 to 29 bases were designed to amplify genomic DNA from 64 grapevine cultivars under more-stringent PCR conditions. Only, two primer pairs, OpA111175p17R/ p17F and OpD10800p14R/p14F, still produced a specific SCAR marker, the ’Folle blanche’ ScA111175 and the ’Malvasía Sitges’ ScD10800 respectively. Moreover, the ScA111175 marker was amplified only in ’Folle blanche’ among the 64 cultivars tested with a large annealing temperature range using either two different Taq DNA polymerases or two separate thermocyclers. In addition, we discuss the initial polymorphism originated by the RAPD technique and suggest a new design of SCAR primers to obtain reliable cultivar-specific SCAR markers from single PCR-based bands for identification purposes.
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    URL: http://dx.doi.org/10.1007/s001220051597
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    Comparing AFLP, RAPD and RFLP markers for measuring genetic diversity in melon (2000)
    Springer
    Theoretical and applied genetics 101 (2000), S. 860-864 
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    ISSN: 1432-2242
    Keywords: Key words Melon ; AFLP ; RFLP ; RAPD ; Genetic similarity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Three different types of molecular markers, RAPD, AFLP and RFLP were used to measure genetic diversity among six genotypes of Cucumis melo L. Each line represented a different melon genotype: Piel de Sapo, Ogen, PI161375, PI414723, Agrestis and C105. A number of polymorphic RAPD, AFLP and RFLP bands were scored on all materials and the genetic similarity measured. Clustering analysis performed with the three types of markers separated the genotypes into two main groups: (1) the sweet type, cultivated melons and (2) the exotic type, not cultivated melons. While the data obtained suggest that all three types of markers are equally informative, AFLPs showed the highest efficiency in detecting polymorphism.
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    Comparative analysis of phenotypic and genotypic diversity among plantain landraces (Musa spp., AAB group) (2000)
    Springer
    Theoretical and applied genetics 101 (2000), S. 1056-1065 
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    ISSN: 1432-2242
    Keywords: Key words Plantain ; Musa ; RAPD ; Phenotype ; Breeding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Genetic diversity amongst 76 plantain landraces has been studied using RAPD analysis at two levels of intensity and compared with groupings based on phenotypic indices and morphotype. There was a good correlation (R2=0.78) between estimates of genetic diversity based on 76 RAPD bands and 164 RAPD bands. However, there was a poor correlation between RAPD-based estimates of genetic diversity and a phenotypic index based on agronomic characters. There was also a poor correlation between RAPD analyses and morphotype group (based on bunch type and stature). These results suggest that the traditional designations of plantain landraces based on morphotype do not provide a true reflection of overall genetic divergence. Similarly, classification systems using phenotypic indices based on agronomic characters may not provide accurate taxonomic differentiation. The level of genetic divergence within morphogroups based on bunch type suggests that True Horn plantains are derived from False Horn plantains which in turn are derived from French plantains. Genetic divergence was found to be generally quite low within the plantain landrace genepool, which is consistent with the proposed evolution of this germplasm through somatic mutation of a relatively small number of introductions. However, putative synonyms/duplicates have been shown to be genetically distinct. In contrast, a group of 12 landraces have been identified that are highly distinct from one another (showing 20–35% dissimilarity). Fertile members of this group may be useful for generating genetically diverse 2x and 4x breeding populations that can be used in breeding secondary triploid hybrid plantain varieties.
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    URL: http://dx.doi.org/10.1007/s001220051580
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    Molecular phylogeny of Gossypium species by DNA fingerprinting (2000)
    Springer
    Theoretical and applied genetics 101 (2000), S. 931-938 
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    ISSN: 1432-2242
    Keywords: Key words Gossypium species ; RAPD ; Phylogeny ; Cluster ; Diversity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Total genomic DNA from 31 available Gossypium species, three subspecies and one interspecific hybrid, were analysed to evaluate genetic diversity by RAPD, using 45 random decamer primers. A total of 579 amplified bands were observed, with 12.9 bands per primer, of which 99.8% were polymorphic. OPJ-17 produced the maximum number of fragments while the minimum number of fragments was produced with primer OPA-08. Cluster analysis by the unweighted paired group method of arithmetic means (UPGMA) showed six main clusters. Cluster ’A’ consisted of two species and one subspecies of the A-genome, with a 0.78–0.92 Nei’s similarity range. Cluster B, composed of all available tetraploid species and one interspecific hybrid, showed the same sister cluster. Nei’s similarity ranged from 0.69 to 0.84. The B-genome formed the UPGMA sister cluster to the E-genome species. Cluster ’C’ consisted of five Gossypium species of which three belong to the B-genome, with Nei’s similarity values of 0.81 to 0.86. Although there was considerable disagreement at lower infra-generic ranks, particularly among the D- genome (diploid New World species) and C-genome (diploid Australian species) species. The sole F-genome species Gossypium longicalyx was resolved as a sister group to the D-genome species. Gossypium herbaceum and G. herbaceum Africanum showed the maximum Nei’s similarity (0.93). Minimum similarity (0.29) was observed between Gossypium trilobum and Gossypium nelsonii. The average similarity among all studied species was 50%. The analysis revealed that the interspecific genetic relationship of several species is related to their centre of origin. As expected, most of the species have a wide genetic base range. The results also revealed the genetic relationships of the species Gossypium hirsutum to standard cultivated Gossypium barbadense, G. herbaceum and Gossypium arboreum. These results correspond well with previous reported results. The level of variation detected in closely related genotypes by RAPD analysis indicates that it may be a more efficient marker than morphological marker, isozyme and RFLP technology for the construction of genetic linkage maps.
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    URL: http://dx.doi.org/10.1007/s001220051564
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    Kinetic Analysis of the Decomposition of Chelates of Di-alkyldithiocarbamate of Cd(II) (2000)
    Springer
    Journal of thermal analysis and calorimetry 59 (2000), S. 633-642 
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    ISSN: 1572-8943
    Keywords: cadmium ; dialkyldithiocarbamate ; kinetics ; thermal decomposition ; thermogravimetry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The thermal decomposition kinetics of the solid complexes Cd(S2 CNR2 )2 , where R =C2 H5 , n -C3 H7 , n -C4 H9 or iso -C4 H9 , was studied by using isothermal and non-isothermal thermogravimetry. The superimposed TG/DTG/DSC curves revealed that thermal decomposition reactions occur in the liquid phase. The kinetic model that best fitted the experimental isothermal TG data was the one-dimensional phase-boundary reaction-controlled process R1 . The thermal analysis data suggested the thermal stability sequence Cd(S2 CNBun 2 )2 〉Cd(S2 CNPrn 2 )2 〉Cd(S2 CNBui 2 )2 〉Cd(S2 CNEt2 )2 , which accords with the sequence of stability of the apparent activation energies.
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    Kinetic and Thermodynamic Studies of Facial and Meridional uns-cis-[Co(eddp)gly] Complexes (2000)
    Springer
    Journal of thermal analysis and calorimetry 59 (2000), S. 807-814 
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    ISSN: 1572-8943
    Keywords: facial and meridional Co(III) complexes ; kinetics ; thermodynamics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Thermal properties of facial and meridional uns-cis-[Co(eddp)gly]0.5H2O complexes were investigated by means of DSC and TG techniques. It wasshown that the processes of thermal decomposition of these complexes are multi-stepdegradation processes, which can also be well separated into individual steps, depending onthe molecular symmetry. Thus, the process of thermal degradation of the meridional isomerof the above complex consists of 4 well-separated steps in the temperature interval from 100to 500°C. The corresponding kinetic and thermodynamic parameters of this process weredetermined, and a possible mechanism is discussed.
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    Thermal Decomposition Kinetics of Some Metal Complexes of N,N-diethyl-n '-benzoylthiourea (2000)
    Springer
    Journal of thermal analysis and calorimetry 61 (2000), S. 955-965 
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    ISSN: 1572-8943
    Keywords: kinetics ; metal complexes
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    Topics: Chemistry and Pharmacology
    Notes: Abstract Thermogravimetry (TG) and differential thermal analysis (DTA) were performed on the complexes with general formula (M(DEBT)n (where M =Fe, Co, Ni, Cu or Ru; n =2, or 3 and DEBT=N,N-diethyl-N'-benzoylthiourea). Derivative thermogravimetric (DTG) curves were also recorded in order to obtain decomposition data on the complexes. The complexes of Fe(III), Co(II), Ni(II), Cu(II) and Ru(III) displayed two- or three-stage decomposition patterns when heated in a dynamic nitrogen atmosphere. Mass loss considerations relating to the decomposition stages indicated the conversion of the complexes to the sulfides or to the corresponding metal alone (Cu, Ru, NiS, CoS or FeS). Mathematical analysis of the TG and DTG data showed that the order of reaction varied between 0.395 and 0.973. Kinetic parameters such as the decomposition energy, the entropy of activation and the pre-exponential factor are reported.
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    Fast Gas Adsorption Measurements For Complicated Adsorption Mechanisms (2000)
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    Journal of thermal analysis and calorimetry 62 (2000), S. 429-433 
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    ISSN: 1572-8943
    Keywords: adsorption ; fast measurement ; gravimetry ; kinetics ; sorption ; kw6
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Jäntti introduced a method to reduce the time required for the stepwise measurement of adsorption isotherms. After each pressure change he measured the adsorbed mass three times and calculated its equilibrium value at the new pressure. In the present paper, we discuss the applicability of this method in a broader scope without starting from a given combination of sorptive and adsorbent and the influence of measuring inaccuracies. The method is applied to detect whether the adsorption process is based on more than one adsorption mechanism or not.
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    Study of Thermal Decomposition Kinetics of Low-temperature Reaction of Ammonium Perchlorate by Isothermal TG (2000)
    Springer
    Journal of thermal analysis and calorimetry 63 (2000), S. 375-386 
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    ISSN: 1572-8943
    Keywords: activation energy ; ammonium perchlorate ; decompositon ; isothermal ; kinetics ; thermogravimetry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The kinetics of the thermal decomposition of ammonium perchlorate at temperatures between 215 and 260°C is studied, in this work, by measuring the sample mass loss as a function of time applying the isothermal thermogravimetric method. From the maximum decomposition rate – temperature dependence two different decomposition stages, corresponding to two different structural phases of ammonium perchlorate, are identified. For the first region (215–235°C), corresponding to the orthorhombic phase, the mean value of the activation energy of 146.3 kJ mol–1, and the pre-exponential factor of 3.43⋅1014 min–1 are obtained, whereas for the second region (240–260°C), corresponding to the cubic phase, the mean value of the activation energy of153.3 kJ mol–1, and the pre-exponential factor of 4.11⋅1014 min–1 are obtained.
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    Theoretical and Experimental Investigations of The Decomposition of 10-methylacridinium Halides (2000)
    Springer
    Journal of thermal analysis and calorimetry 60 (2000), S. 35-43 
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    ISSN: 1572-8943
    Keywords: kinetics ; 10-methylacridinium halides ; thermodynamics ; thermogravimetric investigations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract 10-Methylacridinium chloride, bromide and iodide were prepared in crystalline forms (the first two salts as monohydrates) and subjected to thermogravimetric investigations. Decomposition of the compounds is initially accompanied by the liberation of water (in case of monohydrates), halomethanes and acridine molecules. As decomposition proceeds, side reactions occur which are reflected in a complex pattern of thermogravimetric curves. TG traces corresponding to the initial decomposition stage were used to determine the kinetic characteristics of the thermal dissociation of the salts. MNDO/d, AM1 and PM3 methods were employed independently to examine reaction pathways and to predict thermodynamic and kinetic barriers for the thermal decomposition of the compounds. These data were subsequently supplemented with theoretically determined crystal lattice energies, which enabled the relevant characteristics for the decomposition of crystalline phases to be predicted. The theoretically predicted characteristics are qualitatively comparable with those originating from thermogravimetric investigations, which allows one to believe that both are valid.
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    URL: http://dx.doi.org/10.1023/A:1010160132175
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    Thermal Decomposition of Triazine Herbicides. I. 1,2-(4-chloro-6-ethylamino-1,3,5-triazin-2-ylamino)-2-methylpropionitrile (cyanazine) (2000)
    Springer
    Journal of thermal analysis and calorimetry 60 (2000), S. 103-110 
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    ISSN: 1572-8943
    Keywords: cyanazine ; DSC ; kinetics ; thermal stability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Cyanazine was taken as an example for investigations under the influence of different conditions on thermal decomposition of triazine herbicides. DSC measurements were carried out under atmospheric pressure and hermetically closed, under pressure 1.3 kPa. The influence of the pressure on the constant reaction rate of decomposition of cyanazine was discussed. It was also proved that the predicted reaction constant rates from isothermal and non-isothermal measurements are consistent.
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    Influence of Gas Atmosphere on Removal of Sulphate Groups From Titanium Oxide (2000)
    Springer
    Journal of thermal analysis and calorimetry 60 (2000), S. 247-255 
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    ISSN: 1572-8943
    Keywords: desulfuration ; gas atmosphere ; kinetics ; thermal decomposition ; titanium dioxide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The studies were devoted to determination of the effect of gas atmosphere and its pressure on the second step of decomposition of hydrated titanium dioxide (HTD) promoted by sulfate groups. It has been found that thermal decomposition of HTD at temperatures above 300°C consists of a number of processes such as dehydroxylation, desulfuration, recrystallization and sintering of solid grains, photochemical processes (if the decomposition proceeds in the presence of light) and adsorption of gas phase components (in the presence of air or SO2). Kinetic parameters characterizing this step of decomposition have been determined for processes carried out in vacuum and in argon or air atmospheres (at a pressure of 13.33hPa). The kinetic curves of decomposition carried out in the presence of gases capable of being adsorbed on the surface of partly dehydrated HTD are featured by local extrema due to simultaneous processes of decomposition and adsorption of gas components.
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    Solid State Coordination Chemistry. The quantitative thermoanalytical study of thermal dissociation reactions (2000)
    Springer
    Journal of thermal analysis and calorimetry 60 (2000), S. 9-15 
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    ISSN: 1572-8943
    Keywords: coordination compounds ; kinetics ; thermal dissociation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Physicalo-chemical importance of the quantitative study of kineticliability of coordination compounds in thermal dissociation processes is considered. Muchattention is given to the proof of the physicalo-chemical meaning and validity of kineticparameters calculated from thermoanalytical data. Experimental data (thermal dissociation ofcoordination compounds and clathrates with such a matrix) are discussed.
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    The Effect of Cross-linked Polyethylene As a Surface Modifier on Crystallization of Polypropylene (2000)
    Springer
    Journal of thermal analysis and calorimetry 60 (2000), S. 401-407 
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    ISSN: 1572-8943
    Keywords: cross-linking ; isothermal crystallization ; kinetics ; modification ; polypropylene ; silica
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The effect of addition of silica on the parameters of isothermal crystallization of polypropylene has been investigated. It was found that the covering of the silica surface by a layer of low-density polyethylene leads to a deactivation of the filler regarding the positive effect on the polypropylene crystallization rate parameters. Cross-linking of the surface polyethylene layer results in a stronger attachment of the modifying polymer to the filler surface and the deactivation effect of the silica surface modification is more pronounced.
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    Formation of Cr(II) Species in the H2/CrO3 System. Parameter control (2000)
    Springer
    Journal of thermal analysis and calorimetry 60 (2000), S. 541-547 
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    ISSN: 1572-8943
    Keywords: Cr(II) ; chromium trioxide ; kinetics ; reduction ; thermal analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The thermal behaviour of CrO3 on heating up to 600°C in dynamic atmospheres of air, N2 and H2 was examined by thermogravimetry (TG), differential thermal analysis (DTA), IR spectroscopy and diffuse reflectance spectroscopy (DRS). The results revealed three major thermal events, depending to different extents on the surrounding atmosphere: (i) melting of CrO3 near 215°C (independent of the atmosphere), (ii) decomposition into Cr2(CrO4)3 at 340–360°C (insignificantly dependent), and (iii) decomposition of the chromate into Cr2O3 at 415–490°C (significantly dependent). The decomposition CrO3 → Cr2(CrO4)3 is largely thermal and involves exothermic deoxygenation and polymerization reactions, whereas the decomposition Cr2(CrO4)3 → Cr2O3 involves endothermic reductive deoxygenation reactions in air (or N2) which are greatly accelerated and rendered exothermic in the presence of H2. TG measurements as a function of heating rate (2–50°C min−1) demonstrated the acceleratory role of H2, which extended to the formation of Cr(II) species. This could sustain a mechanism whereby H2 molecules are considered to chemisorb dissociatively, and then spillover to induce the reduction. DTA measurements as a function of the heating rate (2–50°C min−1) helped in the derivation of non-isothermal kinetic parameters strongly supportive of the mechanism envisaged.
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    Kinetic Modeling of Advanced Inorganic Glass-ceramics Formation by Crystal Growth From Pre-existing Nuclei (2000)
    Springer
    Journal of thermal analysis and calorimetry 60 (2000), S. 667-674 
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    ISSN: 1572-8943
    Keywords: accommodation function ; crystal growth ; glass-ceramics ; kinetics ; number of nuclei ; thermal history
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Kinetic modeling of the crystal growth from pre-existing nuclei was reexamined to obtain a fundamental information about the controlled crystallization of glasses during formation of advanced inorganic glass-ceramics. Methods of kinetic analysis were reviewed by taking account of thermal history of the sample within the temperature range of nucleation. An accommodation function depending on the thermal history was introduced in the kinetic equation. The role of the accommodation function was reinvestigated when determining the activation energy from a series of kinetic curves. The kinetic description of the crystal growth in the samples with different thermal history was generalized by extrapolating the rate behavior to infinite temperature.
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    Temperature Modulated DSC. Theoretical interpretation (2000)
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    Journal of thermal analysis and calorimetry 60 (2000), S. 333-343 
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    ISSN: 1572-8943
    Keywords: base line ; DSC ; kinetics ; modeling ; thermodynamics ; TMDSC
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The application of non-linear heating program to a heat-flux DSC apparatus has attracted much attention. From thermodynamics viewpoint, it is shown that the variation of enthalpy of a sample changing with temperature change is due, to both the true heat capacity of the sample and the enthalpy of some transformations occurring in the sample, characterized by its degree of advance. Using the simple assumption that the rate of the transformation is proportional to the distance from the thermodynamic equilibrium, an electrical model of the thermal event is given. Using the coupled cell model of the DSC apparatus, we show how to obtain the rate of transformation of the sample and heat capacity, which is directly related to the base line of the experiment.
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    Practical Thermogravimetry (2000)
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    Journal of thermal analysis and calorimetry 60 (2000), S. 759-778 
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    ISSN: 1572-8943
    Keywords: decomposition temperature ; error sources ; gas-flow and vapor control ; kinetics ; thermogravimetry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The well-known divergence between the present ‘state of the art’ of thermogravimetry and industrial requirements is discussed. Sources of errors are analyzed and the optimization of measuring conditions is discussed regarding the problems associated with static and dynamic (flow) atmospheres, and interactions between materials and gases or vapors. Recommendations for gas-flow control systems and vapor sources are given. Thermal stability and the kinetics of gas-evolving, reversible, thermal decompositions of solids are discussed. The scope of TG-derived kinetics for practical use is examined. Some new characteristic points of TG curves are proposed and defined, e.g. ‘procedure-independent decomposition temperature’ and ‘augmented decomposition temperature’ (obtained at pseudo-equilibrium conditions).
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    The Thermodynamic Driving Force in the Kinetic Evaluation of Thermoanalytical Curves (2000)
    Springer
    Journal of thermal analysis and calorimetry 60 (2000), S. 879-886 
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    ISSN: 1572-8943
    Keywords: driving force ; kinetics ; rate equation ; reversible reactions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract This paper outlines the different ways of taking the distance from thermodynamic equilibrium into account in kinetic studies based on thermoanalytical experiments. The three main approaches are: (i) avoiding or neglecting the effect of the reverse reaction, (ii) describing the influence of distance from equilibrium on apparent kinetic parameters, and (iii) incorporating a driving force factor in the rate equation. Finally, the contradiction of the microscopic nature of the processes and the macroscopic character of the usual rate equation are briefly discussed.
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    Kinetic Analysis of the Thermal Decomposition of Synthetic Malachite by CRTA (2000)
    Springer
    Journal of thermal analysis and calorimetry 60 (2000), S. 943-954 
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    ISSN: 1572-8943
    Keywords: CRTA ; kinetics ; self-generated atmospheric conditions ; synthetic malachite ; thermal decomposition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The kinetic behavior of the thermal decomposition of synthetic malachite was investigated by means of CRTA under different conditions of reduced pressure, flowing gases and quasi-isobaric atmospheres. The thermal decomposition was found to proceed at lower temperatures under the influence of the self-generated gases, CO2 and H2O. From a viewpoint of chemical equilibrium, the normal and opposite effects on the overall kinetics were observed for the self-generated CO2 and H2O, respectively. The complexity of the present reaction is also reflected by the variations of the apparent kinetic parameters which depend on the applied and self-generated atmospheric conditions. The practical usefulness of CRTA when applied to a complicated thermal decomposition is discussed as exemplified by the kinetic approaches to the present reaction.
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    Thermal Studies on Some Lanthanide Complexes (2000)
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    Journal of thermal analysis and calorimetry 61 (2000), S. 151-156 
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    ISSN: 1572-8943
    Keywords: complexes ; kinetics ; TG-DTA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Thermal behaviour of a few lanthanide complexes of the type ML3(I) [M=Eu,Gd; HL=4,4,4-trifluoro- 1-(2-napthyl)-1,3-butanedione and EuL30.5dmm dmm=2,6-dimethylmorpholine(II)], has been investigated. From thermogravimetric(TG) curves, the decomposition pattern of the compounds has been analysed on the basis of mass loss data. The order and activation energy of the thermal decomposition reactions have been elucidated. From differential thermal analysis (DTA) studies, the heat of reaction and rate of thermal decomposition reaction have been enumerated.
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    Non-isothermal Kinetic Study of the Heterogeneous Thermal Decomposition of a Mannich Compound (2000)
    Springer
    Journal of thermal analysis and calorimetry 61 (2000), S. 239-242 
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    ISSN: 1572-8943
    Keywords: kinetics ; Mannich compounds ; thermal decomposition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The authors present data concerning the evaluation of kinetic parameters of the decomposition of a Mannich compound by using the classical method of constant heating rate thermal analysis and the new one of controlled rate thermal analysis (CRTA). The data processed using the CRTA method allow to obtain more reliable kinetic parameters according to the proposed reaction mechanism.
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    URL: http://dx.doi.org/10.1023/A:1010197632277
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    Polypropylene Crystallization in an Ethylene-propylene-diene Rubber Matrix (2000)
    Springer
    Journal of thermal analysis and calorimetry 61 (2000), S. 437-450 
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    ISSN: 1572-8943
    Keywords: crystallization ; EPDM ; kinetics ; morphology ; PP ; rubber
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The effect of the incorporation of an amorphous immiscible polymer (ethylene-propylene-diene- terpolymer) on the PP crystallization kinetics and thermodynamics is investigated by thermal analysis. The results of the investigation have shown that EPDM acts as a nucleant agent. A marked decrease of the half time of PP crystallization, τ1/2 , as well as a sensible increase of the overall crystallization rate, K n , has been observed in the presence of EPDM. Moreover, at any crystallization temperature, a minimum of τ1/2 , is obtained at 25% EPDM content in the blend. The Avrami model has been successfully applied to describe the crystallization kinetics of the blend. The kinetic curves obtained under non-isothermal conditions confirm the results obtained under isothermal conditions and demonstrate the nucleant action of the EPDM phase on the PP crystallization.
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    URL: http://dx.doi.org/10.1023/A:1010165317028
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    TG and DTA Study of the Thermal Dehydration of Metal-exchanged Zeolite-4A Samples (2000)
    Springer
    Journal of thermal analysis and calorimetry 62 (2000), S. 721-727 
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    ISSN: 1572-8943
    Keywords: kinetics ; metal exchange ; thermaldehydration ; zeolite
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Zeolite-4A is a hydrated aluminosilicate which becomes more hydrated when exchanged with transition metals. In this work, the dehydration kinetics of cobalt, nickel and copper(II)-exchanged zeolite-4A were studied by means of TG and DTA over the temperature range from 20 to 500°C, and the numbers of water molecules in the metal-exchanged zeolite samples were calculated. It was observed that, as the ionic radius of the hydrated metal increased, the number of water molecules also increased. The loss of water from the zeolite samples generally occurred in the temperature range 100–300°C and was manifested in the DTA graphs by an extended endothermic effect. The DTA curves demonstrated that the peak position shifted towards lower temperatures as the metal concentration increased or, in other words, the water of hydration increased. The kinetic parameters (order of reaction and activation energy) were calculated via the Coats and Redfern method. The process of dehydration was found to follow first-order kinetics.
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    Kinetic Equations for Thermal Dissociation Processes. Part I. KEKAM equation (2000)
    Springer
    Journal of thermal analysis and calorimetry 63 (2000), S. 359-374 
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    ISSN: 1572-8943
    Keywords: KEKAM equation ; kinetics ; thermal dissociation of solids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Relationships have been established between the average conversion degree and the dissociation time for polydisperse granular material, taking its grain size distribution into account. It has been checked in which cases the kinetic curves obtained by a numerical solution can be described in terms of KEKAM equation.
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    Critical Analysis of the Isoconversional Methods for Evaluating the Activation Energy. II. The activation energy obtained from isothermal data corresponding to two successive reactions (2000)
    Springer
    Journal of thermal analysis and calorimetry 63 (2000), S. 465-469 
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    ISSN: 1572-8943
    Keywords: isoconversional methods ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract An analysis is presented of the consequences of the use of a one term equation containing apparent activation parameters, instead of the true rate equation to describe two successive decomposition reactions undergone by a solid compound. It is demonstrated that the apparent activation energy, obtained by means of isoconversional differential and integral methods, varies with the conversion degree for a relatively narrow temperature range and with temperature at a given value of the conversion degree. The activation energy values obtained with the isoconversional differential method are higher than the corresponding values obtained with the isoconversional integral method.
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    Kinetics of Thermal Decomposition of Plumbo-jarosite (2000)
    Springer
    Journal of thermal analysis and calorimetry 59 (2000), S. 869-875 
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    ISSN: 1572-8943
    Keywords: decomposition ; kinetics ; plumbo-jarosite
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract An investigation was carried out on the kinetics of thermal decomposition of plumbo-jarosite. The kinetic models of dissociation of the compounds in the ore were identified. The results of the kinetic studies and the mechanism of the process are discussed. The thermal decomposition of plumbo-jarosite occurs in three stages: the first up to 763, the second up to 1023 and the third up to 1223 K, the corresponding activation energy values being 62.2, 60.3 and 98.0 kJ mol–1 , respectively.
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    Thermal Characterization of Passivated Nanometer Size Aluminium Powders (2000)
    Springer
    Journal of thermal analysis and calorimetry 61 (2000), S. 805-818 
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    ISSN: 1572-8943
    Keywords: aluminium ; ARC ; DSC ; kinetics ; nanometric size ; SDT ; TG
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The thermal properties of Alex, a nanosized Al powder, were determined using various techniques, including DSC, TG, simultaneous TG-DTA (SDT) and accelerating rate calorimetry (ARC). The results demonstrate that the specific heat capacities of nano and micron size Al powders are similar between 30 and 400°C. Dynamic and isothermal methods were used to determine the kinetic parameters for the oxidation reaction of Alex, which was detected at an onset temperature of 481°C. The results obtained were in good agreement with each other. From the ARC experiments, exotherms were detected near 340 and 260°C for experiments started at ambient pressure and at 0.72 MPa, respectively.
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    Thermal and Spectroscopic Studies on the Decomposition of Some Aminoguanidine Nitrates (2000)
    Springer
    Journal of thermal analysis and calorimetry 61 (2000), S. 861-871 
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    ISSN: 1572-8943
    Keywords: DAGN ; kinetics ; mechanism and IR spectroscopy ; TAGN ; thermal decomposition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Diaminoguanidine nitrate (DAGN) and triaminoguanidine nitrate (TAGN),potential energetic materials in emerging propulsion technology with high mass impetus at low isochoric flame temperature have been studied as regards kinetics and mechanism of thermal decomposition using thermogravimetry (TG), differential thermal analysis (DTA),infrared spectroscopy (IR) and hot stage microscopy. Kinetics of thermolysis has been followed by isothermal TG and IR. For the initial stage of thermolysis of DAGN the best linearity with a correlation coefficient of 0.9976 was obtained for the Avrami-Erofe'evequation, n=2, by isothermal TG. The activation energy was found to be 130 kJ mol–1 and logA=11.4. The initial stage of thermolysis of TAGN also obeyed the Avrami-Erofe'ev equation, n=2, with a correlation coefficient of 0.9975by isothermal TG and the kinetic parameters are E=160.0 kJ mol–1 and logA=16.0. High temperature IR spectra showed exquisite preferential loss in intensity of the NH2, NH, N–N stretching and CNN bending. Spectroscopic and other results favour deamination reaction involving the rupture of the N–N bond as the primary step in the thermal decomposition.
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    Fractal Approach in the Kinetics of Solid-Gas Decompositions. Part II (2000)
    Springer
    Journal of thermal analysis and calorimetry 61 (2000), S. 979-984 
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    ISSN: 1572-8943
    Keywords: kinetics ; nucleation-growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The author presents some applications of the fractal geometry in the kinetics of heterogeneous decomposition of solids.
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    Study of The Mechanism and Kinetic Parameters of The Thermal Decomposition of Cobalt Sulphate Hexahydrate (2000)
    Springer
    Journal of thermal analysis and calorimetry 59 (2000), S. 935-942 
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    ISSN: 1572-8943
    Keywords: CoSO46H2O ; kinetics ; thermal decomposition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Thermogravimetry (TG-DTG), and differential thermal analysis (DTA) were used in the study of the kinetics of decomposition of cobalt sulphate hexahydrate under an air atmosphere. The kinetics of the particular stages of CoSO4 6H2 O decomposition were evaluated from the dynamic mass loss data. The values of the kinetic parameters for each stage of the thermal decomposition were calculated from the α(T) data by using the integral method, applying the Coats-Redfern approximation.
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    Kinetic Study of the Accelerating Effect of Coal-burning Additives on the Combustion of Graphite (2000)
    Springer
    Journal of thermal analysis and calorimetry 62 (2000), S. 681-685 
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    ISSN: 1572-8943
    Keywords: coal-burning additive ; combustion ; graphite ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The catalytic and accelerating effects of three coal-burning additives (CBA) on the burning of graphite were studied with the help of thermogravimetric (TG) analysis. The kinetic study on the catalytic oxidation of the graphite doped with CBA was carried out and the results were presented. The results show that the CBA can change the carbon oxidation/combustion course by catalytic action and change the activation energy, thus improving the combustion efficiency.
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    Critical Analysis of the Isoconversional Methods for Evaluating the Activation Energy. I. Theoretical background (2000)
    Springer
    Journal of thermal analysis and calorimetry 63 (2000), S. 457-463 
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    ISSN: 1572-8943
    Keywords: isoconversional methods ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract It is demonstrated that, if the activation energy depends on the degree of conversion, its values obtained by isoconversional differential and integral methods are different.
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    Modeling of the Phase Transformation Induced by Ball Milling in Anatase TiO2 (2000)
    Springer
    Journal of materials synthesis and processing 8 (2000), S. 139-144 
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    ISSN: 1573-4870
    Keywords: TiO2 ; phase transformations ; mechanical alloying ; kinetics ; modeling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract A high-pressure and high-temperature phase of TiO2 : TiO2 II is formed transiently during room-temperature high-energy ball milling of anatase TiO2 : TiO2 anatase → TiO2 II → TiO2 rutile. Rutile is the only phase present after prolonged ball milling. The present paper focuses on the influences of physical and chemical processing conditions on the transformation kinetics. The effects of two milling parameters on the kinetics of phase transformation of anatase TiO2 were investigated: the nature of milling tools and the powder-to-ball weight ratio R. Granulometric characterizations and TEM observations have demonstrated that the transformation of TiO2 anatase into TiO2 II occurs without fracturing of particles and that TiO2 II nanograins form at the surface of anatase particles. The parameter R affects only the transformation rate. For a given R, the transformation rate is the largest with alumina grinding tools, intermediate with zirconia tools, and the smallest with steel tools. The parameters involved in current models of the mechanical alloying process do not suffice to explain the differences in transformation rates observed here. A parameter, which takes into account the influence of the mechanical properties of grinding materials, is considered.
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    URL: http://dx.doi.org/10.1023/A:1011351807629
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    Relating Single-Impact Events to Macrokinetic Features in Mechanical Alloying Processes (2000)
    Springer
    Journal of materials synthesis and processing 8 (2000), S. 271-277 
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    ISSN: 1573-4870
    Keywords: Comminution ; kinetics ; mechanical alloying ; phase transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract It has been shown that structural evolution occurring in powder mixtures subjected to mechanical treatment by milling follow well-defined conversion trends as a function of milling time. Sigmoidal curves were observed in the case of the mechanical alloying of transition metal mixtures, whereas a simpler kinetic course with a progressively decreasing transformation rate was found to characterize the disordering process of intermetallic equilibrium compounds by mechanical milling. Under the stipulation that collisions are the dominant energy transfer events, a kinetic model is developed to relate the observed macrokinetic features to the discrete powder fractions, which transform at each impact. Because of its intrinsic qualities, the milling process was regarded as discrete processing. A statistical approach was followed to work out a set of differential equations, solutions of which provide a sound description of the transformation kinetics in terms of conventional rate expressions. The model allows one to reproduce the different kinetic behaviors by means of a single, unifying mathematical formalism. Furthermore, quantifying the structural evolution rate by suitable kinetic constants permits the exploration of the reactive behavior of a system treated under different milling regimes or to compare, on an absolute basis, different systems processed under similar conditions.
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    High-Temperature Oxidation Behavior of the Co-Base Superalloy DZ40M in Air (2000)
    Springer
    Oxidation of metals 53 (2000), S. 351-360 
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    ISSN: 1573-4889
    Keywords: Co-base superalloy ; high-temperature oxidation ; kinetics ; structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The oxidation behavior of the Co-base superalloy DZ40M was studied in air at900–1100°C for times of up to 2000 hr. The results indicated thatthis alloy can grow a protective oxide scale at 900 and 1000°C duringisothermal oxidation, but not at 1100°C because of serious cracking andspalling of the oxide scales. Moreover, an internal-precipitate zone formedin the subsurface region of the alloy at all temperatures and times. Theprecipitates were rich in Cr in the vicinity of the alloy–scaleinterface and rich in Al deep in the alloy. The internal-precipitatemorphology changed from a granular to needlelike shape with increasingoxidation temperature.
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    Global climate change and regional sustainable development: the case of Mackenzie Basin in Canada (2000)
    Springer
    Integrated assessment 1 (2000), S. 21-36 
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    ISSN: 1573-1545
    Keywords: integrated assessment ; climate change ; regional sustainability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Cohen et al. [16] suggest that in order to explore ways to bring climate change (CC) and sustainable development (SD) research together, it is necessary to develop more heuristic tools that can involve resource users and other stakeholders. In this respect, this paper focuses on methodological development in research to study climate change impacts and regional sustainable development (RSD). It starts with an introduction of an integrated land assessment framework (ILAF) which is part of the integrated phase of the Mackenzie Basin Impact Study (MBIS) in Canada. The paper then provides some articulation on how the integrated approach was applied in the Mackenzie Basin to show implications of climate change for RSD.
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    Models at the interface between science and society: impacts and options (2000)
    Springer
    Integrated assessment 1 (2000), S. 267-280 
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    ISSN: 1573-1545
    Keywords: participatory integrated assessment ; climate change ; low energy society
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Within the CLEAR project a new approach to integrated assessment modelling has been developed for the participatory integrated assessment of regional climate change involving citizens' focus groups. The climate change decision problem was structured by focusing separately on climate impacts and mitigation options. The attempt was made to link the different scales of the problem from the individual to the global level. The abstract topic of climate change was related to options on the level of a citizen's individual lifestyle. The option of a low energy society was emphasised in order to embed the climate change decision problem in a wider range of societal concerns. Special emphasis was given to the characterisation and communication of uncertainties. The chosen approach allows different kinds of uncertainties in one framework to be addressed. The paper concludes with a summary of the experience made, and recommendations for the use of models in participatory integrated assessments.
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    Natural climate variability and climate change in the North-Atlantic European region; chance for surprise? (2000)
    Springer
    Integrated assessment 1 (2000), S. 301-306 
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    ISSN: 1573-1545
    Keywords: CLEAR ; natural climate variability ; climate change ; atmosphere ; ocean
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Long-term variability in the North Atlantic Oscillation (NAO) and the Atlantic thermohaline ocean circulation (THC) are both shaping the European climate on time scales of decades and longer. Possible linear and non-linear changes in the characteristics of these natural climate modes due to global warming are an important source of uncertainty in long-term regional projections of future climate changes.
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    Assessing alpine plant vulnerability to climate change: a modeling perspective (2000)
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    Integrated assessment 1 (2000), S. 307-320 
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    ISSN: 1573-1545
    Keywords: climate change ; ecological impact assessment ; alpine and subalpine belts ; plant distribution ; statistical modeling ; local scale ; GIS ; GLM ; Swiss Alps
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The potential ecological impact of ongoing climate change has been much discussed. High mountain ecosystems were identified early on as potentially very sensitive areas. Scenarios of upward species movement and vegetation shift are commonly discussed in the literature. Mountains being characteristically conic in shape, impact scenarios usually assume that a smaller surface area will be available as species move up. However, as the frequency distribution of additional physiographic factors (e.g., slope angle) changes with increasing elevation (e.g., with few gentle slopes available at higher elevation), species migrating upslope may encounter increasingly unsuitable conditions. As a result, many species could suffer severe reduction of their habitat surface, which could in turn affect patterns of biodiversity. In this paper, results from static plant distribution modeling are used to derive climate change impact scenarios in a high mountain environment. Models are adjusted with presence/absence of species. Environmental predictors used are: annual mean air temperature, slope, indices of topographic position, geology, rock cover, modeled permafrost and several indices of solar radiation and snow cover duration. Potential Habitat Distribution maps were drawn for 62 higher plant species, from which three separate climate change impact scenarios were derived. These scenarios show a great range of response, depending on the species and the degree of warming. Alpine species would be at greatest risk of local extinction, whereas species with a large elevation range would run the lowest risk. Limitations of the models and scenarios are further discussed.
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    Analysis of Aluminum—Yeast Hexokinase Interaction: Modifications on Protein Structure and Functionality (2000)
    Springer
    The protein journal 19 (2000), S. 199-208 
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    ISSN: 1573-4943
    Keywords: Aluminum ; yeast hexokinase ; preferential interactions ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The aluminum and yeast hexokinase interaction was studied. Structural changes were correlated with variations in protein functionality. Results show two different behaviors: At low metal concentrations preferential adsorption of metal (and water exclusion) induces aggregate formation. No significant changes in the protein structure occur, but there is a continuous loss of activity (from the first concentration). At large salt concentrations a monomerization process and a conformational change in the secondary structure as well as in the three-dimensional structure take place. This change reduces the percentage of α-helix conformation, gives thermal stability to the protein, and allows the exposure of some tryptophan residue and hydrophobic regions. The protein inhibition increases. Conformational change and monomerization may allow access of the metal to the substrate site, mainly the ATP site. The inhibition in any case is of mixed type with a competitive component.
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    A Comparative Study of Human Muscle and Brain Creatine Kinases Expressed in Escherichia coli (2000)
    Springer
    The protein journal 19 (2000), S. 59-66 
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    ISSN: 1573-4943
    Keywords: Creatine kinase ; human ; expression ; brain ; muscle ; purification ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract We report the expression of the human muscle (CK-MM) and brain (CK-BB) creatine kinases in Escherichia coli. The proteins have been purified to apparent homogeneity and several of their physical and kinetic properties investigated. In the process, we have conclusively verified the correct DNA sequence of the genes encoding the respective isozymes, and determined the correct primary structure and mass of the gene products. Alignment of the primary sequences of these two enzymes shows 81% sequence identity with each other, and no obvious gross structural differences. However, Western blot analyses demonstrated the general lack of antigenic cross-reactivity between these isozymes. Preliminary kinetic analyses show the K m and k cat values for the creatine and MgATP substrates are similar to values reported for other isozymes from various tissues and organisms. The human muscle and brain CKs do not, however, exhibit the synergism of substrate binding that is observed, for example, in rabbit muscle creatine kinase.
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    RAPD markers linked to a gene for resistance to pine needle gall midge in Japanese black pine (Pinus thunbergii) (2000)
    Springer
    Theoretical and applied genetics 100 (2000), S. 391-395 
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    ISSN: 1432-2242
    Keywords: Key words Pinus thunbergii ; Pine needle gall midge ; RAPD ; Bulked segregant analysis ; Linkage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Linkage of RAPD markers to a single dominant gene for resistance to pine needle gall midge was investigated in Japanese black pine (Pinus thunbergii). Three primers that generated linked markers were found after 1160 primers were screened by bulked segregant analysis. The distances between the resistance gene, R, and the marker genes OPC06580, OPD01700, and OPAX192100 were 5.1 cM, 6.7 cM and 13.6 cM, respectively. OPC06580 was in coupling phase to R, whereas OPD01700 and OPAX192100 were in repulsion phase to R. A linkage map for a resistant tree was constructed using 96 macrogametophytes. In linkage analysis, 98 out of 127 polymorphic markers were assigned to 17 linkage groups and six linked pairs. The total length of this map was 1469.8 cM, with an average marker density of 15.6 cM. The genome length was estimated to be 2138.3 cM, and the derived linkage map covered 67.5% of the genome. Although the linked markers OPC06580, OPAX192100, and OPD01700, belonged to the same linkage group, no precise positions were found for OPC06580 or OPD01700.
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    Characterization and molecular analysis of transgenic plants obtained by microprotoplast fusion in sunflower (2000)
    Springer
    Theoretical and applied genetics 101 (2000), S. 1250-1258 
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    ISSN: 1432-2242
    Keywords: Key words Micronuclei ; Microprotoplasts ; Chromosome transfer ; RAPD ; Helianthus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Asymmetric somatic hybrid (ASH) plants were obtained by PEG-mediated mass fusion of microprotoplasts from perennial Helianthus species and hypocotyl protoplasts of Helianthus annuus. The formation of micronuclei in perennial sunflower cell cultures was induced, at early log phase, by addition of the herbicides amiprophos-methyl or oryzalin. Sub-diploid microprotoplasts were isolated by high-speed centrifugation and the smallest enriched by sequential filtration through nylon sieves of decreasing pore size. Fusion products were cultured and the regenerated plants phenotypically, genetically and cytologically characterized. DNA analysis using RAPD markers revealed that 28 out of 53 regenerated plants were asymmetric hybrids. Subsequent nuclear-DNA flow cytometric analysis showed that these plants had a higher DNA content than the receptor H. annuus, suggesting that they represented addition lines. Cytological investigation of the metaphase cells of 16 hybrids revealed an addition of 2–8 extra chromosomes in these plants. The phenotype of most ASH plants resembled H. annuus. These results indicate that micronuclear induction and asymmetric somatic hybridization represent a potent tool for partial genome transfer aimed at the specific transfer of economically important traits in breeding programs.
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    URL: http://dx.doi.org/10.1007/s001220051604
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    Transfer of PLRV resistance fromSolanum verrucosum Schlechdt to potato (S. tuberosum L.) by protoplast electrofusion (2000)
    Springer
    Potato research 43 (2000), S. 31-42 
    Details
    ISSN: 1871-4528
    Keywords: somatic hybrids ; potato leafroll virus ; RAPD ; Solanum wild species ; pollen fertility
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Somatic fusions between an accession of the diploid wild speciesSolanum verrucosum and a dihaploid S.tuberosum genotype were produced in order to incorporate resistance to potato leafroll virus (PLRV). In total 15 somatic hybrids out of 16 regenerants were obtained. Identification of hybrids was based on additive RAPD patterns, general morphological characteristics, chromosome numbers and chloroplast counts in stomata guard cells. A field trial was performed with the hybrids, their two parents and the control cultivar Kennebec to assess field performance and phenotypic variability. Yield parameters varied considerably among somatic hybrids. Some of the hybrids gave significantly higher yields, tuber numbers and tuber weights than both parents. Pollen fertility of hybrids ranged from 19 to 77%. Twelve hybrids were found to be resistant to PLRV.
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    URL: http://dx.doi.org/10.1007/BF02358511
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    Stabilization of ammonium dinitramide in the liquid phase (2000)
    Springer
    Russian chemical bulletin 49 (2000), S. 1974-1976 
    Details
    ISSN: 1573-9171
    Keywords: ammonium dinitramide ; thermal decomposition ; kinetics ; stabilization ; isotope composition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The kinetics of accumulation of the main products of thermal decomposition of ammonium dinitramide in the melt was investigated. The isotope composition of nitrogen-containing gases evolved by the decomposition of 15NH4N(NO2)2 and NH4 15N(NO2)2 was found. Easily oxidized salts, amines, amides, iodides, and other compounds soluble in the melt interfere with the liquid-phase decomposition of ammonium dinitramide.
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    URL: http://dx.doi.org/10.1023/A:1009555405171
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    The kinetics and mechanism of cyclodimerization of alkylthiopropenals (2000)
    Springer
    Russian chemical bulletin 49 (2000), S. 1977-1980 
    Details
    ISSN: 1573-9171
    Keywords: 2-alkylthiopropenals ; Diels–Alder reaction ; kinetics ; reaction mechanism ; 2,5-dialkylthio-3,4-dihydro-2H-pyran-2-carbaldehyde ; IR spectroscopy ; ab initio calculations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The kinetics of 2-alkylthiopropenals cyclodimerization was studied in the temperature range from -7 to +42 °C in heptane and at 20 °C in various solvents. The rate constants for cyclodimerization of 2-alkylthiopropenals are four orders of magnitude higher than those for dimerization of the oxygen-containing analogs, 2-alkoxypropenals, and are independent of the solvent polarity and substituent steric constant. The activation parameters for 2-butylthiopropenal cyclodimerization were estimated. The distribution of electron density in the 2-methoxy- and 2-methylthiopropenals molecules was calculated by the ab initio method. From comparison of the HOMO and LUMO energies for these aldehydes it was concluded that the ratio between the cyclodimerization rates for 2-alkylthio-, 2-ethoxypropenals, and propenal is determined by the HOMO–LUMO gap.
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    URL: http://dx.doi.org/10.1023/A:1009507522009
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    Cooperative Interactions in Photosensitized Modification of DNA with Oligonucleotide-derived Binary Reagents (2000)
    Springer
    Molecular biology 34 (2000), S. 814-822 
    Details
    ISSN: 1608-3245
    Keywords: DNA ; kinetics ; oligonucleotide derivatives ; photomodification ; sensitization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Quantitative characteristics of thermodynamic and kinetic cooperativity arising in the process of photomodification of a single-stranded DNA fragment with binary systems of oligonucleotide conjugates forming an active site on the target were studied. Oligonucleotides of the binary system were complementary to adjacent segments of the DNA target, and contained arylazide (X) and perylene (S) residues covalently attached to their terminal phosphates. Upon irradiation at the perylene absorption wavelength, the target was modified by the arylazide residue, which was activated owing to the contiguity with the sensitizing perylene group in the tandem complex. Basing on the kinetic data, the constants of association of both derivatives of oligonucleotides with the target were determined: K x = 1.13 · 106 M–1, K s = 1.49 · 104 M–1. It was determined that association of both oligonucleotides with the target proceeded with a positive cooperativity characterized by parameter α = 45. The kinetic cooperativity parameter β was found to be approximately equal to 200; this characterized the acceleration of target modification in complex with the binary reagent versus that in the absence of sensitizer.
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    URL: http://dx.doi.org/10.1023/A:1026619607955
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    Screening of heterozygous DNA markers in shiitake (Lentinula edodes) using de-dikaryotization via preparation of protoplasts and isolation of four meiotic monokaryons from one basidium (2000)
    Springer
    Journal of wood science 46 (2000), S. 395-400 
    Details
    ISSN: 1611-4663
    Keywords: Lentinula edodes ; Heterozygous DNA marker ; RAPD ; de-dikaryotization ; Protoplast
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract A suitable screening method for heterozygous DNA markers in shiitake,Lentinula edodes (Berk.) Pegler, is reported. Monokaryons were derived from a dikaryon by de-dikaryotization via protoplast formation. Compatibility of the monokaryons was determined by pairwise culture on agar plates. We selected the primers to amplify polymorphic fragments among the original strain (Hokken600∶H600) and two monokaryons (H600PP-39 and H600PP-67) showing compatibility. A total of 135 fragments were selected as specific random amplified polymorphic DNAs (RAPDs) resulting from 56 primers of the 147 primers tested. Furthermore, we tested whether the polymorphic fragments segregated into 2∶2 among four strains isolated from a basidium. Most of the polymorphic fragments (about 97.8%) showed 2∶2 segregation among the four strains. We concluded that the polymorphic fragments were heterozygous if they were detected in either of the monokaryons (H600PP-39 and H600PP-67) and segregated to 2∶2 among four meiotic strains (H600B-1,-2, -3, and -4). A total of 132 heterozygous DNA markers were therefore selected from a dikaryon of shiitake (Hokken600∶H600).
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    URL: http://dx.doi.org/10.1007/BF00776403
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    Population structure ofSclerotium rolfsii in peanut fields (2000)
    Springer
    Mycoscience 41 (2000), S. 145-148 
    Details
    ISSN: 1618-2545
    Keywords: mycelial compatibility ; RAPD ; Sclerotium rolfsii
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Sclerotium rolfsii isolates from peanut fields in Ibaraki were classified into mycelial compatibility groups (MCGs) based on the barrage zone formation. A total of 132 isolates collected from four fields within a 120 m radius in 1994 comprised four MCGs; MCG A (71 isolates), B (34 isolates), C (26 isolates) and D (one isolate). Fields 1 and 2 were occupied exclusively by MCG A. MCG A also predominated in field 3. In field 4, MCGs A, B and C were dominant. Population structure in 3 additional fields was determined in 1997. All 11 isolates from Field 5, which was 400 m distant from field 1, belonged to MCG C. A total of 42 isolates from fields 6 and 7, 2.5 km distant from other fields and 100 m distant from each other, were all MCG A. These results suggested that the population structure ofS. rolfsii was simple. RAPD fingerprintings showed that most isolates of the same MCG were clonal.
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    URL: http://dx.doi.org/10.1007/BF02464323
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    Functional Properties of Lactate Dehydrogenase from Dunaliella salina and Its Role in Glycerol Synthesis (2000)
    Springer
    Russian journal of plant physiology 47 (2000), S. 761-771 
    Details
    ISSN: 1608-3407
    Keywords: Dunaliella salina ; lactate dehydrogenase ; kinetics ; glycerol synthesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The dependence of the catalytic properties of lactate dehydrogenase (LDH, EC 1.1.1.27) from a halophilic alga Dunaliella salina, a glycophilic alga Chlamydomonas reinhardtii, and from porcine muscle on glycerol concentration, medium pH, and temperature was investigated. Several chemical properties of the enzyme from D. salina differentiated it from the LDH preparation obtained from C. reinhardtii and any homologous enzymes of plant, animal, and bacterial origin. (1) V max of pyruvate reduction manifested low sensitivity to the major intracellular osmolyte, glycerol. (2) The affinity of LDH for its coenzyme NADH dropped in the physiological pH region of 6–8. Above pH 8, NADH virtually did not bind to LDH, while the enzyme affinity for pyruvate did not change considerably. (3) The enzyme thermostability was extremely low: LDH was completely inactivated at room temperature within 30 min. The optimum temperature for pyruvate reduction (32°C) was considerably lower than with the enzyme preparations from C. reinhardtii (52°C) and porcine muscle (61°C). (4) NADH greatly stabilized LDH: the ratio of LDH inactivation constants in the absence of the coenzyme and after NADH addition at the optimum temperature in the preparation from D. salina exceeded the corresponding indices of LDH preparations from C. reinhardtii twelve times and from porcine muscle eight times. The authors believe that these LDH properties match the specific metabolism of D. salina which is set at rapid glycerol synthesis under hyperosmotic stress conditions. The increase of cytoplasmic pH value produced in D. salina by the hyperosmotic shock can switch off the terminal reaction of the glycolytic pathway and thus provide for the most efficient utilization of NADH in the cycle of glycerol synthesis. As LDH is destabilized in the absence of NADH, this reaction is also switched off. In the course of alga adaptation to the hyperosmotic shock, glycerol accumulation and the neutralization of intracellular pH stabilize LDH, thus creating the conditions for restoring the complete glycolytic cycle.
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    URL: http://dx.doi.org/10.1023/A:1026607211936
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    Kinetic study of a thermostable β-glycosidase of Thermus thermophilus. Effects of temperature and glucose on hydrolysis and transglycosylation reactions (2000)
    Springer
    Glycoconjugate journal 17 (2000), S. 377-383 
    Details
    ISSN: 1573-4986
    Keywords: β-glycosidase ; temperature dependence ; kinetics ; glucose ; transglycosylation ; (Thermus thermophilus)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A β-glycosidase of a thermophile, Thermus thermophilus, belonging to the glycoside hydrolase family 1, was cloned and overexpressed in Escherichia coli. The purified enzyme (Ttβgly) has a broad substrate specificity towards β-D-glucoside, β-D-galactoside and β-D-fucoside derivatives. The thermostability of Ttβgly was exploited to study its kinetic properties within the range 25–80[emsp4 ]°C. Whatever the temperature, except around 60[emsp4 ]°C, the enzyme displayed non-Michaelian kinetic behavior. Ttβgly was inhibited by high concentrations of substrate below 60[emsp4 ]°C and was activated by high concentrations of substrate above 60[emsp4 ]°C. The apparent kinetic parameters (k cat and K m ) were calculated at different temperatures. Both k cat and K m increased with an increase in temperature, but up to 75[emsp4 ]°C the values of k cat increased much more rapidly than the values of K m . The observed kinetics might be due to a combination of factors including inhibition by excess substrate and stimulation due to transglycosylation reactions. Our results show that the substrate could act not only as a glycosyl donor but also as a glycosyl acceptor. In addition, when the glucose was added to reaction mixtures, inhibition or activation was observed depending on both substrate concentration and temperature. A reaction model is proposed to explain the kinetic behavior of Ttβgly. The scheme integrates the inhibition observed at high concentrations of substrate and the activation due to transglycosylation reactions implicating the existence of a transfer subsite.
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    Stromatolitic communities in Mediterranean streams: adaptations to a changing environment (2000)
    Springer
    Biodiversity and conservation 9 (2000), S. 379-392 
    Details
    ISSN: 1572-9710
    Keywords: climate change ; cyanobacteria ; ectoenzymes ; Mediterranean ; nutrient limitation ; photosynthesis ; stromatolite
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A stromatolitic microbial mat extensively covers La Solana streambed, a calcareous Mediterranean stream. This stromatolite shows remarkable biological and physiological diversity. It is mainly composed by cyanobacteria, with Rivularia and Schizothrix as the most abundant taxa. The stromatolite is photosynthetically adaptated to the high irradiances reaching the streambed. Photosynthetically active chlorophyll is present even in the lowest layers of the stromatolite, indicating the presence of well-preserved cyanobacteria in that part. Diffusion of gases and nutrients within the stromatolite can be possible because of the high porosity of the crust. It has been experimentally established that the stromatolite recovers heterotrophic and autotrophic activities in a few hours, after being desiccated for long periods. Recovery after desiccation is indicative of the high resilience of this community to environmental extremes, which are common in Mediterranean climatic regimes. The stromatolitic community is adapted to nutrient limitation, both to low availability of inorganic phosphorus and nitrogen (that constrain growth of primary producers), and to low dissolved organic carbon (mainly affecting heterotrophs). Stromatolitic heterotrophs mainly rely on the organic carbon stored in the crust as the main organic carbon source. These strategies are the direct response of the stromatolite to oligotrophy, and justify the restricted occurrence in stream systems affected by organic pollution.
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    URL: http://dx.doi.org/10.1023/A:1008954801397
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    Heathlands functioning in a perspective of climate warming – Estimation of parameters, elements for discrete event simulation (2000)
    Springer
    Plant ecology 149 (2000), S. 107-118 
    Details
    ISSN: 1573-5052
    Keywords: Calluna vulgaris ; demography ; nitrogen cycle ; climate change ; modelling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Three Calluna vulgaris (L.) Hull heathlands (1100, 1500 and 1780 m altitude) are studied in order to establish and estimate parameters which will be integrated in a discrete event simulation of heathland functioning in the case of a 2 °C climate warming. The sites, situated in the Chaîne des Puys and the Massif du Sancy (France), present similar conditions for Calluna growth: bedrock (trachyt), exposure and slope, so that they can be compared on a climatic basis. Main parameters sampled are: age distributions, life expectancies, layering probabilities, annual growths, biomasses (standing crop), C/N rates and potential respiratory of soils. In addition, experiments were carried out on germination, hypocotyle elongation and growth of mycorrhizal fungi in order to estimate the inhibitory-to-growth action against the substitution process. On one stand (exhibiting gaps) the patch structure of Calluna plants was recorded and mapped. The rising of biomass expected is calculated according to the Aerts's model, as a function of nitrogen availability which would increase under a scenario of climate warming. From a similar point of view, layering probabilities, life expectancies and inhibition of seedlings survival modelling – under a linear model assumption – are proposed.
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    URL: http://dx.doi.org/10.1023/A:1009805112857
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    Climate Change Adaptation in the U.K. Water Industry: Managers' Perceptions of Past Variability and Future Scenarios (2000)
    Springer
    Water resources management 14 (2000), S. 137-156 
    Details
    ISSN: 1573-1650
    Keywords: climate adaptation ; climate change ; droughtmanagement ; England and Wales water supply
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Geography
    Notes: Abstract In this article, the relationship between U.K. watercompanies' perceptions of past climatic extremes andtheir effect on resilience to future climatic changeis explored. Perceptions and activities related topast and future dry periods was investigated throughinterviews with managers at the ten major English andWelsh water supply/sewerage companies, and severalsmaller, water-only companies. Several of thecompanies report that they have observed a trendtowards drier summers in their regions, and a number of companies say that they have observed a changetowards more intensive rainfall of shorter duration. Recent supply measures in a number of regions havebeen aimed at improving storage and distributionrelated to the perceived change in rainfall intensity.A new requirement to incorporate regional climatechange scenarios in future supply assumptions appearsto have had little impact on planning in the region todate. Many water resource planners believe that thescenarios generated are too aggregated and do notencourage a precautionary approach to planning. Somemanagers believe that records of historical droughtconditions, such as experienced in 1933/1934 or 1995/1996,as worst-case scenarios provide a better basis for planning.
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    Identification and Characterization of Malaysian River Catfish, Mystus nemurus (C&V): RAPD and AFLP Analysis (2000)
    Springer
    Biochemical genetics 38 (2000), S. 63-76 
    Details
    ISSN: 1573-4927
    Keywords: AFLP ; RAPD ; polymorphism ; Mystus nemurus.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract This work represents the first application of the amplified fragment length polymorphism (AFLP) technique and the random amplified polymorphic DNA (RAPD) technique in the study of genetic variation within and among five geographical populations of M. nemurus. Four AFLP primer combinations and nine RAPD primers detected a total of 158 and 42 polymorphic markers, respectively. The results of AFLP and RAPD analysis provide similar conclusions as far as the population clustering analysis is concerned. The Sarawak population, which is located on Borneo Island, clustered by itself and was thus isolated from the rest of the populations located in Peninsular Malaysia. Both marker systems revealed high genetic variability within the Universiti Putra Malaysia (UPM) and Sarawak populations. Three subgroups each from the Kedah, Perak, and Sarawak populations were detected by AFLP but not by RAPD. Unique AFLP fingerprints were also observed in some unusual genotypes sampled in Sarawak. This indicates that AFLP may be a more efficient marker system than RAPD for identifying genotypes within populations.
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    URL: http://dx.doi.org/10.1023/A:1002740613034
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    Male-specific DNA markers from African catfish (Clarias gariepinus) (2000)
    Springer
    Genetica 110 (2000), S. 267-276 
    Details
    ISSN: 1573-6857
    Keywords: Clarias ; RAPD ; sex determination ; siluroid ; teleost
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We searched for sex-specific DNA sequences in the male and female genomes of African catfish, Clarias gariepinus (Burchell, 1822) by comparative random amplified polymorphic DNA (RAPD) assays performed on pooled DNA samples. Two sex-linked RAPD markers were identified from the male DNA pool and confirmed on individual samples, showing good agreement with phenotypic sex. Both markers were isolated, cloned and characterized. The first marker (CgaY1) was nearly 2.6 kb long, while the length of second one (CgaY2) was 458 bp. Southern blot analysis with a CgaY1 probe showed strong hybridizing fragments only in males and not in females under stringent conditions, indicating the presence of multiple copies of CgaY1 in the male genome. When tested by zoo blot on the genomes of two closely related species from the Clariidae family, CgaY1 hybridized to the DNA of Heterobranchus longifilis and generated a faint male-specific band at low stringency. CgaY2 produced similar hybridization pattern in both sexes of C. gariepinus, C. macrocephalus and H. longifilis. Specific primers were designed to the sequences and the markers were amplified in multiplex PCR reactions together with a control band common to all individuals. This allowed for rapid, molecular sexing of the species on the basis of a simple three band (male) versus one band (female) pattern. According to our knowledge these are the first sex-specific DNA markers isolated from a siluroid fish species.
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    URL: http://dx.doi.org/10.1023/A:1012739318941
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    Dispersal of the Cotton Boll Weevil (Coleoptera: Curculionidae) in South America: Evidence of RAPD Analysis (2000)
    Springer
    Genetica 108 (2000), S. 127-136 
    Details
    ISSN: 1573-6857
    Keywords: boll weevil ; dispersal ; origin ; RAPD ; South America
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract RAPD technique provides useful information on the geographic origin and dispersal of the boll weevil Anthonomus grandis in South America. Nine populations from Argentina, Brazil, Paraguay, Mexico and USA were analyzed. Weevils were captured on native plants (Misiones province, Argentina) and on cotton cultures, except the sample from the United States (USDA laboratory-reared colony). A sample of the ‘Peruvian square weevil’, A. vestitus, from Ecuador, was included in the analysis in order to compare interspecific variation. The four primers used in the analysis revealed 41 ‘anonymous loci’. The neighbor-joining tree based on Nei's distances and values of Nm (migrants per generation), indicate that genetic similarity between samples from Tecomán (Mexico) and Puerto Iguazú (Argentina), is higher than among remaining South American populations. This result supports an hypothesis of natural occurrence of the boll weevil in South America, prior to extensive cotton cultivation. Population outbreaks of the species would be associated with increase of agricultural lands.
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    Statistical Properties of Stimulated Raman Scattering in a Nonlinear Regime (2000)
    Springer
    Journal of applied spectroscopy 67 (2000), S. 981-989 
    Details
    ISSN: 1573-8647
    Keywords: nonlinear regime of stimulated Raman scattering ; fluctuation ; Stokes radiation ; kinetics ; spectrum ; distribution function
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Statistical properties of the Raman scattering of an intense step pulse are investigated by numerical solution of the equations of a semi-classical theory with assignment of a random Gaussian distribution of the initial polarization over the sample. The probability density functions of the intensity, energy, delay time, and width of a Stokes pulse and also of the position, height, and width of the spectral peaks of the first incidental Stokes component with the preservation of the phase memory of scattering centers are calculated. The influence of collisional dephasing on the fluctuation of these characteristics is considered.
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    Identification of Meloidogyne chitwoodi, M. fallax and M. hapla Based on SCAR-PCR: A Powerful Way of Enabling Reliable Identification of Populations or Individuals that Share Common Traits (2000)
    Springer
    European journal of plant pathology 106 (2000), S. 283-290 
    Details
    ISSN: 1573-8469
    Keywords: diagnostics ; RAPD ; root-knot nematodes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract This study describes the development of species-specific pairs of PCR primers for the root-knot nematodes Meloidogyne chitwoodi, M. fallax and M. hapla that amplify species-specific RAPD fragments. After sequencing the fragments, longer primers were designed to complement the terminal sequences of the polymorphic DNA fragments. The resulting pairs of primers were used to generate the sequence-characterized amplified regions (SCARs). Using the developed pairs of SCAR primers, SCAR fragments of M. chitwoodi, M. fallax or M. hapla were easily amplified from DNA extracts from juveniles, egg masses, females of the particular nematode species investigated, either present alone, in a mixture with other nematode species or in infested plant material. A specially designed multiplex assay using three pairs of SCAR primers enabled the identification of multiple species in a mixture in a single PCR step. Single juveniles were easily identified by applying this multiplex assay followed by a subsequent multiplex PCR using three pairs of nested primers. The SCAR-PCR-based assays described have potential to be optimized for routine practical diagnostic tests. The usefulness of converting RAPD markers into SCAR markers is discussed.
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    Effect of Compaction Scheme on Property Distribution for Cumulative Charge Facings Formed from a Heterogeneous Powder Composite (2000)
    Springer
    Powder metallurgy and metal ceramics 39 (2000), S. 540-544 
    Details
    ISSN: 1573-9066
    Keywords: compaction ; facing ; cumulative charge ; powder ; composite ; heterogeneous structure ; particle ; kinetics ; surface ; die ; model ; xeroradiogram
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract An experimental and numerical (finite element method) study is carried out for the effect of forming scheme on property distribution for cumulative charge facings made from composite heterogeneous powder material. An experimental procedure is developed for studying powder particle flow kinetics. It is shown that use of composite punches and partition of the moulded material into a number of sub-divisions with their successive compaction achieves a more uniform density distribution for an article. It is demonstrated how the direction of the force of friction on the die walls during compaction affects the compaction of articles with faces that are not perpendicular to the direction of the pressing. The results obtained make it possible to select the optimum compaction regime taking account of production features connected with powder material composition as well as service characteristics.
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    URL: http://dx.doi.org/10.1023/A:1011359626701
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    Simultaneous Determination of the Heat and the Quantity of Vapor Sorption Using a Novel Microcalorimetric Method (2000)
    Springer
    Pharmaceutical research 17 (2000), S. 701-706 
    Details
    ISSN: 1573-904X
    Keywords: vapor sorption ; molar heat of adsorption ; kinetics ; isothermal microcalorimetry ; recrystallization ; hydration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Purpose. In this study, instrumentation for measuring vapor sorptionenthalpies and sorption uptakes simultaneously with an isothermalmicrocalorimeter is introduced. Various pharmaceutical modelsubstances undergoing phase transitions when exposed to humid conditions(25°C), were employed to evaluate the usefulness and sensitivity ofthe constructed experimental method. Methods. The sample is placed in the sample vessel of a RH cell andthe moisture content of the air flow is controlled. From the RH cellthe air flow is conducted into a subsequent perfusion cell in which asaturated salt solution has been loaded. The RH cell and perfusioncells are positioned in the sample sides of two twin calorimetric units.Depending on the moisture content in the outlet flow leaving thepreceding RH cell, the heat flow signal from the subsequent perfusioncell will vary. By means of blank measurement with identical settings,the rate of water sorption can be calculated and, by integration, theamount of sorbed water is obtained. Results. Amorphous lactose and cefadroxil undergo recrystallizationwhen the moisture level in the surroundings exceeds the thresholdvalues specific to each compound. During the sorption phase, heat isevolved fairly linearly as a function of consumed moisture, and alsoafter the recrystallization, the heats indicate linear behavior. The heatvalues for the desorption phase of amorphous lactose and the adsorptionof crystalline lactose coincide. With the different anhydrous forms oftheophylline, the hydration takes place more rapidly in the metastableform I, and generally, the process is more energetic in form I. In allcases, the gravimetric results agree with the water sorption uptakescalculated from the calorimetric data. Conclusions. The technique introduced offers a rapid and sensitivemethod to gain new insights into the transitions in which vapors areinvolved. In addition, different kinds of surfaces with various energeticscan now be studied more closely.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007530315652
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  • 95
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    Software dependent phenetic relationships of non-nodulating African species ofAcacia (2000)
    Springer
    Plant systematics and evolution 220 (2000), S. 139-146 
    Details
    ISSN: 1615-6110
    Keywords: Acacia ; classification ; Leguminosae ; morphology ; phenetics ; RAPD ; software ; taxonomy ; UPGMA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The phenetic analysis of non-nodulatingAcacia species by Harrier et al. (1997) was repeated to illustrate how different computer programs may generate alternative UPGMA trees for the very same data, even in the absence of data input order effects (ties). For example, all Harrier et al.'s UPGMA dendrograms produced by software from the Scottish Agricultural Statistics Service differed from those obtained by the packages NTSYS and MVSP87. Particularly, the positions ofA. albida, A. rovumae, andA. pentagona, as well as the relationships betweenDiacanthae andTriacanthae were affected by this phenomenon. Hence, whenever clustering techniques are used, care should be taken to consider possible software-dependent caveats and artefacts. Nevertheless, all programs provided clusterings that largely coincided with the subgeneric and sectional groupings proposed by Vassal (1972) although the positions of some species varied depending on whether morphological or molecular data were considered (e.g.A. albida andA. rovumae).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00985042
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  • 96
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    Inter- and intraspecific genetic variation inHippophae (Elaeagnaceae) investigated by RAPD markers (2000)
    Springer
    Plant systematics and evolution 225 (2000), S. 85-101 
    Details
    ISSN: 1615-6110
    Keywords: Elaeagnaceae ; Hippophae ; sea buckthorn ; Systematics ; taxonomy ; genetic variation ; RAPD
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Genetic diversity has been investigated by the application of molecular markers in, for the first time, all the taxa recognised in recent treatises of the genusHippophae. RAPD (random amplified polymorphic DNA) analyses were conducted with 9 decamer primers, which together yielded 219 polymorphic markers. We found 16 fixed RAPD markers, i.e. markers that either occurred in all plants of a population or were absent from all plants. Several of these markers were useful for analysis of interspecific relationships, whereas others can be considered as taxon-specific markers. Clustering of taxa and populations in our neighbour-joining based dendrogram was in good agreement with some recently suggested taxonomic treatises ofHippophae. Amount and distribution of genetic variability varied considerably between species. Partitioning of molecular variance withinH. rhamnoides supported earlier findings that a considerable part of the total variance resides among subspecies (59.6%) Within-population variability also differed considerably. Percentage polymorphic RAPD loci and Lynch and Milligan within-population gene diversity estimates showed relatively high values for some species close to the geographic centre of origin in Central Asia, e.g.H. tibetana and the putatively hybridogenousH. goniocarpa. Spatial autocorrelation analyses performed on 12 populations ofH. rhamnoides revealed positive autocorrelation of allele frequencies when geographic distances ranged from 0 to 700 km, and no or negative autocorrelation at higher distances. At distances between 700 and 1900 km, we observed deviations from the expected values with strongly negative autocorrelation of allele frequencies. A corresponding relationship between geographic and genetic distances could not be found when the analysis instead was based on one population from each of 8 species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00985460
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  • 97
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    The effects of elevated [CO2] on the C:N and C:P mass ratios of plant tissues (2000)
    Springer
    Plant and soil 224 (2000), S. 1-14 
    Details
    ISSN: 1573-5036
    Keywords: climate change ; CO2 ; decomposition ; leaf ; root ; litter ; nutrient concentration ; nutrient cycle
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The influence of elevated CO2 concentration ([CO2]) during plant growth on the carbon:nutrient ratios of tissues depends in part on the time and space scales considered. Most evidence relates to individual plants examined over weeks to just a few years. The C:N ratio of live tissues is found to increase, decrease or remain the same under elevated [CO2]. On average it increases by about 15% under a doubled [CO2]. A testable hypothesis is proposed to explain why it increases in some situations and decreases in others. It includes the notion that only in the intermediate range of N-availability will C:N of live tissues increase under elevated [CO2]. Five hypotheses to explain the mechanism of such increase in C:N are discussed; none of these options explains all the published results. Where elevated [CO2] did increase the C:N of green leaves, that response was not necessarily expressed as a higher C:N of senesced leaves. An hypothesis is explored to explain the observed range in the degree of propogation of a CO2 effect on live tissues through to the litter derived from them. Data on C:P ratios under elevated [CO2] are sparse and also variable. They do not yet suggest a generalising-hypothesis of responses. Although, unlike for C:N, there is no theoretical expectation that C:P of plants would increase under elevated [CO2], the average trend in the data is of such an increase. The processes determining the C:P response to elevated [CO2] seem to be largely independent of those for C:N. Research to advance the topic should be structured to examine the components of the hypotheses to explain effects on C:N. This involves experiments in which plants are grown over the full range of N and of P availability from extreme limitation to beyond saturation. Measurements need to: distinguish structural from non-structural dry matter; organic from inorganic forms of the nutrient in the tissues; involve all parts of the plant to evaluate nutrient and C allocation changes with treatments; determine resorption factors during tissue senescence; and be made with cognisance of the temporal and spatial aspects of the phenomena involved.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004790612630
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  • 98
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    Comparisons of RFLP and PCR-based markers to detect polymorphism between wheat cultivars (2000)
    Springer
    Euphytica 114 (2000), S. 135-142 
    Details
    ISSN: 1573-5060
    Keywords: Cheyenne ; polymorphism ; RAPD ; recombinant inbred chromosome line(RICL) RFLP ; STS ; SSR ; Triticum aestivum ; Wichita
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Previously chromosome 3A of wheat (Triticum aestivum L.) was reported to carry genes influencing yield, yield components, plant height, and anthesis date. The objective of current study was to survey various molecular marker systems for their ability to detect polymorphism between wheat cultivars Cheyenne(CNN) and Wichita (WI), particularly for chromosome3A. Seventy-seven `sequence tagged site' (STS), 10simple sequence repeat (SSR), 40 randomly amplified polymorphic DNA (RAPD) markers, and 52 restriction fragment length polymorphism (RFLP) probes for wheat homoeologous group 3 chromosomes, were investigated. Three (3.9%) STS-PCR primer sets amplified polymorphic fragments for the two cultivars, of which one was polymorphic for chromosome 3A. Sixty percent of SSR markers detected polymorphism between CNN and WI of which 50% were polymorphic for chromosome 3A. Twenty percent of RAPD markers detected polymorphism between CNN and WI in general, but none of these detected polymorphism for chromosome 3A. Of the fifty-two RFLP probes, 78.8% detected polymorphism between CNN and WI for group 3 chromosomes with one or more of seven restriction enzymes and 42% of the polymorphic fragements were for chromosome 3A. These high levels of RFLP and SSR polymorphisms between two related wheat cultivars could be used to map and tag genes influencing important agronomic traits. It may also be important to reconsider RFLP as the most suitable marker system at least for anchor maps of closely related wheat cultivars.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003993930447
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  • 99
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    RAPD characterization of Brazilian barley (Hordeum vulgare ssp. vulgare) varieties (2000)
    Springer
    Euphytica 111 (2000), S. 127-135 
    Details
    ISSN: 1573-5060
    Keywords: barley varieties ; genetic variability ; Hordeumvulgare ssp. vulgare ; molecular characterization ; RAPD
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Thirteen varieties of Brazilian barley selected for malting qualities were analysed by RAPD (Random Amplified Polymorphic DNA). Amplification with 18 random primers generated 221 reproducible bands, of which 206 bands were polymorphic (93%):of this number, 137 fragments (62%) detected diversity among varieties and 56 bands (25.34%) allowed the distinction of varieties or groups of them. Variation was detected in all Brazilian varieties studied. Within-variety similarities estimated by Jaccard Similarity Coefficient ranged from 0.28 to 0.94, with averages ranging from 0.57 to 0.83, and an overall average of 0.72. Nevertheless, in the cluster analysis representatives of the same variety always fell into the same group and only later joined the other varieties. The average intervarietal similarities estimated by Jaccard Similarity Coefficient ranged from 0.45 to 0.62, with an overall average of 0.52. Many bands or combinations of bands which were responsible for the differentiation of all varieties were detected. Nevertheless, the majority of these bands cannot be considered as diagnostic markers because a great number of them did not occur in many representatives of the variety or had low intensity or even because they were not easily identified in the total pattern of bands.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003878820225
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  • 100
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    An extended random primer amplified region (ERPAR) marker linked to a dominant male sterility gene in cabbage (Brassica oleracea var. capitata) (2000)
    Springer
    Euphytica 112 (2000), S. 267-273 
    Details
    ISSN: 1573-5060
    Keywords: cabbage (Brassica oleracea var. capitata) ; ERPAR ; RAPD ; male sterility gene ; molecular marker
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Similar to SCAR, an extended random primer amplified region (ERPAR) marker is a PCR amplified genomic DNA fragment at a single genetically defined locus. However, ERPAR uses specific primer pairs derived from RAPD primers by adding bases sequentially to their 3′-ends. As an example, an ERPAR marker was derived from a RAPD marker (OT11900) linked to a dominant male sterility gene in cabbage (Brassica oleracea var. capitata). After two cycles of base adding and primer pair screening, a primer pair (5′-TTCCCCGCGACT-3′and 5′-TTCCCCGCGAGA-3′) amplified a single intense band with the same size as OT11900. The identity of the new marker and OT11900 was verified by segregation analysis. The new marker amplified by this extended primer pair was named as EPT11900. The development of ERPAR exploits the importance of 3′-end bases of primers in PCR ERPAR shares advantages of SCAR, but eliminates the need for cloning and sequencing. It is a fast and universal way of converting RAPD markers into stable markers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003903627969
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