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Using a high degree of automation, the Southeast Collaboratory for Structural Genomics (SECSG) has developed high throughput pipelines for protein production, and crystallization using a two-tiered approach. Primary, or tier-1, protein production focuses on producing proteins for members of large Pfam families that lack a representative structure in the Protein Data Bank. Target genomes are Pyrococcus furiosus and Caenorhabditis elegans. Selected human proteins are also under study. Tier-2 protein production, or target rescue, focuses on those tier-1 proteins, which either fail to crystallize or give poorly diffracting crystals. This two tier approach is more efficient since it allows the primary protein production groups to focus on the production of new targets while the tier-2 efforts focus on providing additional sample for further studies and modified protein for structure determination. Both efforts feed the SECSG high throughput crystallization pipeline, which is capable of screening over 40 proteins per week. Details of the various pipelines in use by the SECSG for protein production and crystallization, as well as some examples of target rescue are described.  相似文献   

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Philosophical theories about reduction and integration in science are at variance with what is happenign in science. A realistic approach to science show that possibilities for reduction and integration are limited. The classical ideal of a unified science has since long been rejected in philosophy. But the current emphasis on interdisciplinary integration in philosophy and in science shows that it survives in a different guise. It is necessary to redress the balance, specifically in biology. Methodological analysis shows that many of the grand interdisciplinary theories involving biology actually represent pseudo-integration covered up by inappropriate, overgeneral concepts. Integrationism is not bad, but it must be kept within reasonable bounds. If the present analysis is appropriate, there will have to be fundamental changes in research strategy both in science and in the philosophy of science.  相似文献   

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The development of structural defences, such as the fortification of shells or exoskeletons, is a widespread strategy to reduce predator attack efficiency. In unpredictable environments these defences may be more pronounced in the presence of a predator. The cladoceran Daphniamagna (Crustacea: Branchiopoda: Cladocera) has been shown to develop a bulky morphotype as an effective inducible morphological defence against the predatory tadpole shrimp Triopscancriformis (Crustacea: Branchiopoda: Notostraca). Mediated by kairomones, the daphnids express an increased body length, width and an elongated tail spine. Here we examined whether these large scale morphological defences are accompanied by additional ultrastructural defences, i.e. a fortification of the exoskeleton. We employed atomic force microscopy (AFM) based nanoindentation experiments to assess the cuticle hardness along with tapping mode AFM imaging to visualise the surface morphology for predator exposed and non-predator exposed daphnids. We used semi-thin sections of the carapace to measure the cuticle thickness, and finally, we used fluorescence microscopy to analyse the diameter of the pillars connecting the two carapace layers. We found that D. magna indeed expresses ultrastructural defences against Triops predation. The cuticle in predator exposed individuals is approximately five times harder and two times thicker than in control daphnids. Moreover, the pillar diameter is significantly increased in predator exposed daphnids. These predator-cue induced changes in the carapace architecture should provide effective protection against being crushed by the predator’s mouthparts and may add to the protective effect of bulkiness. This study highlights the potential of interdisciplinary studies to uncover new and relevant aspects even in extensively studied fields of research.  相似文献   

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Ever since the Renaissance speaking about paintings has been a fundamental approach for beholders, especially experts. However, it is unclear whether and how speaking about art modifies the way we look at it and this was not yet empirically tested. The present study investigated to the best of our knowledge for the first time in what way speaking modifies the patterns of fixations and gaze movements while looking at paintings. Ninety nine university students looked at four paintings selected to cover different art historical typologies for periods of 15 minutes each while gaze movement data were recorded. After 10 minutes, the participants of the experimental group were asked open questions about the painting. Speaking dramatically reduced the duration of fixations and painting area covered by fixations while at the same time increasing the frequencies of fixations, gaze length and the amount of repeated transitions between fixation clusters. These results suggest that the production of texts as well-organised sequences of information, structures the gazes of art beholders by making them quicker, more focused and better connected.  相似文献   

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Availability of Zn to plant is hampered by its immobile nature and adverse soil conditions. Thus, Zn deficiency is observed even though high amount is available in soil. Root-shoot barrier, a major controller of zinc transport in plant is highly affected by changes in the anatomical structure of conducting tissue and adverse soil conditions like pH, clay content, calcium carbonate content, etc. Zn deficiency results in severe yield losses and in acute cases plant death. Zn deficiency in edible plant parts results in micronutrient malnutrition leading to stunted growth and improper sexual development in humans. To overcome this problem several strategies have been used to enrich Zn availability in edible plant parts, including nutrient management, biotechnological tools, and classical and molecular breeding approaches.  相似文献   

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Injured employees require medical care and, if disabled, compensation payments for subsistence. The law requires that the employer or insurance carrier supply these benefits promptly. In the absence of prompt and adequate information from the attending physician, these benefits are withheld. The necessary information required to process employee''s claim is that called for on the standard accident report form, commonly called the “pink slip.” Not to supply this minimum information may constitute a hardship on the employee. By supplying more elaborate information than that called for, the physician may be increasing his load of “paper work” immeasurably.  相似文献   

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The reaction of catharanthine with sodium borohydride in methylene chloride was claimed to produce an isomer of the title compound. A spectroscopic re-examination of the product has revealed that it is catharanthine borane.  相似文献   

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This paper summarizes present knowledge of the synanthropic nitrophilous communities dominated by tall herbs on the basis of the present Artemisietea vulgaris database. Floristic variability was examined also in detrended correspondence analysis. Each cluster was inspected for its ecological and floristic consistency. The final interpretable solution comprises five clusters. Species to clusters fidelity was calculated using ? coefficient. The ecological interpretation of the five groups was based on the average Pignatti indicator values. Groups were compared by using Tukey's honest significant difference test in conjunction with ANOVA. Finally, based on the statistical analysis, we established five alliances: Onopordionacanthii, Matricario-Chenopodion, Dauco-Melilotion, Arctionlappae, and Convolvuloarvensis-Elytrigionrepenti.  相似文献   

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This article emphasizes on the present urgent need to think in “Holistic Dimensions” to achieve a sustainable agro-ecosystem. In this respect, the complex network of dynamic interactions in the agro-ecosystem soil at spatiotemporal dimensions holds crucial importance. It reflects the inherent tendency of dynamic ecosystems to achieve a more efficient state successively through improved interactions. The short-sighted and inefficient agro-management during Green Revolution decades has been detrimental to these interactions in agricultural soils, which is widely evident by its boomerang effects (i.e. declining efficiency, productivity and multi-functionality). It jeopardized the internal regulation in our agro-ecosystem's functioning by erosion of efficiency building interactions among biotic and abiotic components. Therefore, a bottom-up as well as top-down approach in the soil management is required to restore and sustain the unaccounted but indispensible ecological subsidies for sustainable agriculture and development, globally. We propose a “commercial ecological agriculture” which should be an amalgamation of sustainable agricultural practices and supported by a progressive co-ordination among all the stakeholders via participatory learning and adaptation with time. It should be least-disturbing, resilience-building, resource (i.e. energy and nutrient) use efficient, site-specific, labor and skill-intensive, low-input, diversified and integrated, and intimately harmonized with nature. It may potentially provide us agricultural sustainability with time in real sense. It would be primarily based on management of interactions indirectly through identification of integrative variables as surrogate, which may help to achieve internal regulation or self-reliance in agroecosystems. Further, it would be helpful to eliminate the widening socio-economic divide and in mitigation of global change in environment (i.e. air, water and soil) and climate. Additionally, it would improve and restore the multifaceted potential of soil, thus quality and productivity, through improved internal regulation on resource-use efficiency.  相似文献   

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Ragweed pollen, which is a major cause of allergic rhinitis in North America and during the last decades, also in parts of the European continent, has not been regarded as a risk in Sweden, since occurrences of Ambrosia have been rare and with two exceptions, ephemeral. During the last four years, however, long-distance transported pollen has been registered in South Sweden. Moreover, seeds are dispersed by man with birdseed and reports on ragweed plants growing at birdtables are becoming more and more common. In warm years, the fruits of these plants mature and are germinative. We argue that there is a risk that ragweed pollen may be a problem in the future in Sweden. Long-distance transport from the continent is likely to be increasingly more common, and in larger amounts, as ragweed is rapidly spreading in Europe. Among the plants now appearing within Sweden, selection is likely to favour phenotypes which are able to fulfil their life-cycle during the indigenous vegetation period, especially in a scenario of global warming.  相似文献   

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