1,902 research outputs found

    Palystes kreutzmanni sp. n. – a new huntsman spider species from fynbos vegetation in Western Cape Province, South Africa (Araneae, Sparassidae, Palystinae)

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    Palystes kreutzmanni sp. n. is described from habitats close to Kleinmond, in the Western Cape Province, South Africa. Spiders of this new species live in the typical fynbos vegetation of the Western Cape region. They build retreats between apical leaves of Leucadendron bushes. The systematic position of Palystes kreutzmanni sp. n. is discussed. Male and female show characters of different species groups, especially the female copulatory organ seems to be unique within the genus Palystes L. Koch, 1875

    Genotype x Environment Interactions of Winter Wheat

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    Winter wheat cultivars for organic farming have to be adapted to highly variable environments. Yield and yield stability, the nutritional value and the bread making quality are here of major importance. Particularly, seed quality, tillering capacity, regeneration ability after harrowing, weed suppression ability, resistance or tolerance against diseases and improved nutrient use efficiency (NUE) under limited nutrient conditions need to be improved by specific breeding efforts (Kunz et al., 2006; Löschenberger et al., 2008). Ten winter wheat cultivars were grown in 2007 in two organic systems of the DOK long-term experiment in CH-Therwil. Eight of these cultivars were tested in 2008 at three organic farms in different pedo-climatic environments in Switzerland to observe genotype x environment interactions under different organic conditions. In contrast to the DOK site on a fertile loess soil, the on-farm sites were located on sandy or sandy-loamy sites with lower inherent yield potential. We assessed grain yield, yield components and parameters related to baking quality and NUE. Grain yield at the on-farm sites ranged between 2.2 t ha-1 and 2.8 t ha-1 and was much lower than at the DOK sites ( 3.7 t ha-1 to 4.2 t ha-1) (Hildermann et al., 2009). Cultivars and sites significantly affected grain yield. Genotype x environment interactions were significant across the three on-farm sites; however they were not significant across all five organically managed sites. Calculated across the on farm sites, there was a tendency towards higher yields of the organically bred cultivars. This effect was statistically significant at the lowest yielding site, where yield of the organically bred cultivars was 14% higher than yields of the conventionally bred cultivars. However, at the DOK sites and averaged across all five organic sites, the organically bred cultivars could not outperform the conventionally bred cultivars. Similar to the grain yield, the total gluten content increased from the on-farm sites to the DOK sites. Irrespective of the site, the gluten index of the cultivars Scaro, Antonius and Caphorn was stable. In contrast, the gluten index of the cultivars Sandomir, CCP and Titlis highly varied between the tested environments. Yield was significantly correlated with grain N yield (r = 0.93) and nitrogen (N) utilization efficiency (NUtE) (r = 0.72). Genotype x environment interactions were not significant for grain N yield, however strongly significant for NUtE (p < 0.01). The conventionally bred cultivars strongly responded to environmental conditions and showed a low NUtE under at low N supply. In contrast, NUtE of the organically bred cultivars Scaro and Sandomir was stable across all test environments. Beside high yields, cultivars suitable for organic farming should achieve high baking quality and nutrient use efficiency under nutrient limited conditions. Among the tested cultivars, the organically bred cultivar Scaro revealed such a performance across all tested sites

    An overnational cereal circuit for developing locally adapted organic seeds of wheat

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    On several locations in Germany and Switzerland, new and local varieties of winter wheat were compared to the variety "Bussard" in trial plots with 2-4 replications. Among other parameters, baking quality and gluten content were analised and discussed

    Backqualität und/oder Brotqualität?

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    Backqualität spielt eine immer wichtigere Rolle im ökologischen Weizenanbau. Der Bericht erläutert anhand von zwei Versuchen die geringe Korrelation zwischen Qualitätsparametern und dem Backergebnis. In beiden Versuchen sind die Korrelationen zwischen Labor- / Felddaten und den Resultaten der Backversuche sehr gering (< 0,6), oder unbedeutend (< 0,5). Der Einfluss der Backtechnologie bleibt aufgrund der größeren Bedeutung auf das Backergebnis weiter zu untersuchen

    Analysis of the Security and Memorability of the Password Card

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    Choosing and remembering secure passwords poses a problem to users. The password card is a proposal intended to help users to cope with this problem. It is a paper card with a grid of random letters, numbers, and symbols, on which users choose a starting point and a walk of adjacent cells. The characters on the traversed cells form the new password. We analyze the security and memorability of passwords created this way. We find that users mostly choose predictable walks and starting points. At the same time, memorability of the passwords seems low. Thus, the password card seems to fail in helping users to choose and remember secure passwords

    3D ultrastructural organization of whole Chlamydomonas reinhardtii cells studied by nanoscale soft x-ray tomography

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    The complex architecture of their structural elements and compartments is a hallmark of eukaryotic cells. The creation of high resolution models of whole cells has been limited by the relatively low resolution of conventional light microscopes and the requirement for ultrathin sections in transmission electron microscopy. We used soft x-ray tomography to study the 3D ultrastructural organization of whole cells of the unicellular green alga Chlamydomonas reinhardtii at unprecedented spatial resolution. Intact frozen hydrated cells were imaged using the natural x-ray absorption contrast of the sample without any staining. We applied different fiducial-based and fiducial-less alignment procedures for the 3D reconstructions. The reconstructed 3D volumes of the cells show features down to 30 nm in size. The whole cell tomograms reveal ultrastructural details such as nuclear envelope membranes, thylakoids, basal apparatus, and flagellar microtubule doublets. In addition, the x-ray tomograms provide quantitative data from the cell architecture. Therefore, nanoscale soft x-ray tomography is a new valuable tool for numerous qualitative and quantitative applications in plant cell biology

    Posttraumatic growth and adjustment to spinal cord injury: moderated by posttraumatic depreciation?

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    Objective: Findings on the relationship of posttraumatic growth (PTG) with adjustment to potentially traumatic events are inconsistent, whereupon posttraumatic depreciation (PTD) has been suggested as a possible moderator. The objective of this study is to investigate the associations between PTG and PTD on one side and life satisfaction and indicators of mental and physical health on the other side in individuals with spinal cord injury (SCI). The primary study aim is to test whether PTD moderates the relationships of PTG and different adjustment indicators. Method: A total of 141 patients administered to one of four Swiss SCI rehabilitation centers completed questionnaires assessing PTG and PTD, different indicators of mental and physical health as well as life satisfaction at discharge from first rehabilitation. Correlational and regression methods were used to examine the research question. Results: PTG and PTD were significantly positively correlated (rs = .47). PTD was significantly associated with lower mental and physical health and lower life satisfaction, with small to large effect sizes. PTD moderated the associations of PTG with symptoms of depression and life satisfaction (β of interaction term = -.18 and .24, respectively). PTG was significantly related to lower levels of symptoms of depression and higher life satisfaction in individuals experiencing moderate to high levels of PTD. In contrast, PTG was not significantly related to these outcomes in individuals with low PTD levels. Conclusion: The neglect of PTD in research partially explains mixed findings on the relationship of PTG and adjustment to potentially traumatic events. Keywords
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