Wirkung von Endoxan auf die Chromosomen von HeLa-Zellen

Mutagenic effects induced by solutions of Cytoxan-Substance and its activated compound (rat-passage) are tested in He-La cells.Cytoxan-substance induces chromatid aberrations as well as mitotic depression 44–48 hs after treatment in proportion to the concentration. 22–24 hs after treatment no effects are seen. Activated Cytoxan induces gaps and breaks in HeLa cells harvested 22 hs after treatment. Reunion-figures are missing.Incubating cultures up to 46 hs after treatment leads to few gaps, more breaks and a high number of reunion-figures.It is not known if activated Cytoxan delays the cell cycle or single phases of the cycle. It is discussed that autoradiographic experiments are nessessary to get more information on sensitive and/or delayed phases of the cycle under influence of activated Cytoxan. Furthermore those studies have proved to be helpful to solve questions about the rejoining mechanism.

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Mit Unterstützung durch die Deutsche Forschungsgemeinschaft.     

The influence of gamma radiation on the biosynthesis of indoles and gibberellins in barley the action of zinc on the restitution of growth substance level in irradiated plants

Investigations were made on the effect of exposing barley seeds to gamma-radiation (5–40 kR), alone and in combination with the application of zinc (soaking the seeds in solutions containing 5.10^?5–5.10^?1% Zn for 12 hours before sowing) on growth and on the content of tryptophan, indole auxins and gibberellin-like substances in seven-day plants. Radiation decreased both growth and the content of tryptophan (e.g. by about 53% at 30 kR), of indole auxins (by about 60% auxin in the zone of IAA on the chromatogram at 30 kR), and also the content of gibberellin-like substances (by about 67% gibberellin content in the zone of GA₃ on the chromatogram) of plants. The irradiation of standard samples of tryptophan, indolyl-acetic acid and gibberellic acid alone with many times greater doses (up to 1000 kR) did not lead to marked radiochemical degradation of these substances. It can be assumed that radiation damages the enzyme systems “synthesizing” natural growth substances in plants. The damaging effect of radiation on auxins is already displayed in the synthesis of tryptophan, which is inhibited. Zinc interacts with the damaging effect of radiation on growth. Optimum concentrations of zinc (5.10^?3% Zn) counteract the effect of radiation, up to doses of about 12 kR, on the growth in height in 7-day plants so that it is equal to the controls. Normal content of tryptophan and auxin in the position of indolecetic acid on chromatograms can only be reached by the addition of zinc when the dose of radiation was not greater than about 8 kR, which is less than the influence exerted by zinc on the restitution of growth. On the other hand, the biosynthesis of gibberellin-like substances at the position of gibberellic acid on chromatograms can be restored by zinc to their original level to doses of up to 30 kR. The increased biosynthesis of auxins and gibberellins caused by zinc in irradiated plants is explained by the activation of the remaining and non—damaged enzyme systems carrying out this biosynthesis. The activation of the biosynthesis of growth substances by zinc will also contribute to the restitution effect of zinc on the growth of plants from irradiated seeds.     

Small fish use the hypoxic pelagic zone as a refuge from predators

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Disentangling vegetation diversity from climate–energy and habitat heterogeneity for explaining animal geographic patterns

Broad‐scale animal diversity patterns have been traditionally explained by hypotheses focused on climate–energy and habitat heterogeneity, without considering the direct influence of vegetation structure and composition. However, integrating these factors when considering plant–animal correlates still poses a major challenge because plant communities are controlled by abiotic factors that may, at the same time, influence animal distributions. By testing whether the number and variation of plant community types in Europe explain country‐level diversity in six animal groups, we propose a conceptual framework in which vegetation diversity represents a bridge between abiotic factors and animal diversity. We show that vegetation diversity explains variation in animal richness not accounted for by altitudinal range or potential evapotranspiration, being the best predictor for butterflies, beetles, and amphibians. Moreover, the dissimilarity of plant community types explains the highest proportion of variation in animal assemblages across the studied regions, an effect that outperforms the effect of climate and their shared contribution with pure spatial variation. Our results at the country level suggest that vegetation diversity, as estimated from broad‐scale classifications of plant communities, may contribute to our understanding of animal richness and may be disentangled, at least to a degree, from climate–energy and abiotic habitat heterogeneity.     

High domestic pig contribution to the local gene pool of free-living European wild boar: a case study in Poland

Rates of hybridization between wild and domesticated animals appear to be increasing worldwide. Recent results suggest that genetic introgression from domestic swine into European wild boar is much more common in local populations than expected, based on pan-European studies. Thus, we screened the genetic purity of 265 free-living wild boars from two hunting areas in Poland by genotyping the melanocortin receptor 1 gene (MC1R) for polymorphism. Unexpectedly, high numbers of individuals with domestic genes (24%) were identified. This suggests that mixed ancestry may be common in Polish wild boar. Among admixed individuals, backcrosses with domestic pig and/or introgressed wild boars were detected (2%). Multiple commercial domestic pig breeds are possibly involved in the introgression observed in the study populations. In addition, the absence of significant differences in the frequency of wild-type allele among two hunting areas suggests high dispersal of individuals and gene flow among populations. We conclude that further study is needed to better understand the mechanisms and sources of introgression in wild boars in Poland.     

Epigallocatechin-3-Gallate Alleviates Salinity-Retarded Seed Germination and Oxidative Stress in Tomato

Journal of Plant Growth Regulation - Salinity is a global environmental problem, restricting crop production in a vast area of agricultural land. Although epigallocatechin-3-gallate (EGCG), the...     

Evaluating the environmental impact of debit card payments

Purpose

Consumers in the Netherlands made more than 3.2 billion debit card transactions at points-of-sale in 2015, corresponding to over half of all point-of-sale payments in that year. This study provides insights into the environmental impact of debit card transactions based on a life cycle assessment (LCA). In addition, it identifies several areas within the debit card payment chain where the environmental impact can be reduced.

Methods

The debit card payment system can be divided into three subsystems: debit cards, payment terminals, and data centers used for transaction processing. Input data for all elements within each subsystem (manufacturing, transport, energy use, and disposal) were retrieved from interviews and literature study. Seven key companies and authorities within the debit card system such as the Dutch Payments Association, two banks, two data centers, one payment terminal producer and a recycling company contributed data. The analysis is conducted using SimaPro, the Ecoinvent 3.0 database and the ReCiPe endpoint (H) impact assessment method.

Results and discussion

One Dutch debit card transaction in 2015 is estimated to have an absolute environmental impact of 470 μPt. Within the process chain of a debit card transaction, the relative environmental impact of payment terminals is dominant, contributing 75% of the total impact. Terminal materials (37%) and terminal energy use (27%) are the largest contributors to this share, while the remaining impact comprises data center (11%) and debit card (15%) subsystems. For data centers, this impact mainly stems from their energy use. Finally, scenario analyses show that a significant decrease (44%) in the environmental impact of the entire debit card payment system could be achieved by stimulating the use of renewable energy in payment terminals and data centers, reducing the standby time of payment terminals and increasing the lifetimes of debit cards.

Conclusions

For the first time, the environmental consequences of electronic card payment systems are evaluated. The total environmental impact of debit card transactions in the Netherlands is relatively modest compared to the impact of cash payments, which are the closest substitute of debit card payments at the point-of-sale. Scenario analysis indicates that the environmental impact can be reduced by 44%.

     

Philip Grime's fourth corner: are there plant species adapted to high disturbance and low productivity?

Grime's CSR species life‐strategy theory (competition–stress–ruderality) provides a conceptual framework to classify species into competitive (growing under high productivity, low disturbance), stress‐tolerant (low productivity, low disturbance) and ruderal (high productivity, high disturbance). Importantly, this classification is based on the assumption that the niche space of disturbance and productivity is filled unevenly: while in productive habitats species can adapt to different disturbance regimes, species of low‐productivity and disturbed habitats do not exist, resulting in a triangular distribution of species optima along axes of disturbance and productivity. This assumption has often been criticised, but it has not yet been put under a rigorous test. Here we use existing data on niche positions of central European plant species to test this hypothesis, namely its prediction that species adapted to jointly stressed (low‐productive) and disturbed habitats do not exist. We use Ellenberg indicator values and newly developed indicator values for disturbance as proxies of species positions in the space of productivity and disturbance. We found that positions of species optima along the gradients of productivity and disturbance severity are not independent of each other, with very few species adapted to low‐productive and severely disturbed habitats. In contrast, there is no relationship between productivity and disturbance frequency; a number of species occur in low‐productive and frequently disturbed habitats. The relationship between productivity and disturbance severity can be either due to tradeoffs between life history traits responsible for response to disturbance and productivity (as originally assumed by Grime) or due to historical rarity of severely disturbed habitats in unproductive conditions and consequent absence of evolution of species adapted to them. Our data are based on one specific flora, shaped by glaciations and early introduction of agriculture, but the question of what causes this pattern can be resolved by future analyses of floras with different evolutionary and ecological histories.