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排序方式: 共有253条查询结果,搜索用时 46 毫秒
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Abstract The blood marker iophenoxic acid, and the fluorescent dye rhodamine B, were evaluated as means of assessing bait consumption in the ferret, Mustela furo. Iophenoxic acid was elevated above baseline concentrations for a minimum of 28 days after dosing, indicating that it is a suitable medium‐term marker. Rhodamine B marked ferrets for a maximum of 7 days, and would therefore have limited operational use with feral ferrets. Iophenoxic acid was used in a field trial to assess the effectiveness of a newly developed baiting strategy for control of wild ferrets. All 21 ferrets captured after field baiting with iophenoxic acid had elevated levels of serum iodine, indicating that the newly developed baiting strategy is highly effective for marking ferrets. 相似文献
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G Eason 《Mathematical biosciences》1991,104(1):21-38
A set of equations that approximate the central core model of the human kidney are solved. It is noted that the solution indicates a limit to the increase in solute concentration in the descending limb of Henle for a given metabolic pump term. Comparison is made with the results of an alternative theory, and numerical results are presented for the increase in solute concentration in the descending limb of Henle. 相似文献
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Summary Previous experiments, using 32P pulse labelling, showed that when roots of Lolium perenne were detached from the shoot, a substantial proportion of the phosphorus in the roots could within a few weeks be released and be captured by another, living plant. This paper describes experiments designed to confirm and further investigate this rapid nutrient transfer. Roots from plants grown with ample N and P were detached and placed in litter bags in soil. They lost up to 60% of their initial N and up to 70% of their P in three weeks. Even when roots were grown with deficient P supply, resulting in C:P ratios of 300–400, they lost 20–30% of their initial P. Time-courses of 32P loss from roots suspended in solution gave results which agreed with these figures. The initially rapid rate of 32P loss had declined greatly within three weeks. In a pot experiment small L. perenne plants showed a marked increase in their N and P content during 30 days after a neighbouring large plant's shoot was removed, supporting rapid capture of nutrients lost from the detached roots. To investigate P loss from roots while attached to the shoot, L. perenne shoots were clipped every four days and 32P loss from the roots measured. After the third clip the rate of loss increased, eventually to more than four times that from the control plants. 相似文献
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BackgroundThe world is undergoing exceptional biodiversity loss. Most conservation efforts target biodiversity hotspots at large scales. Such approach overlooks small-sized local hotspots, which may be rich in endemic and highly threatened species. We explore the importance of mountain rock pools (gueltas) as local biodiversity hotspots in the Sahara-Sahel. Specifically, we considered how many vertebrates (total and endemics) use gueltas, what factors predict species richness, and which gueltas are of most priority for conservation. We expected to provide management recommendations, improve local biodiversity conservation, and simultaneously contribute with a framework for future enhancement of local communities’ economy. The identification of local hotspots of biodiversity is important for revaluating global conservation priorities.Conclusion/SignificanceGueltas are crucial for local biodiversity conservation and human activities. They require urgent management plans in Mauritania’s mountains. They could provide refugia under climate change being important for long-term conservation of Sahara-Sahel biodiversity. Given their disproportional importance in relation to their size, they are local hotspots of biodiversity deserving global attention. 相似文献
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Manolo Rocco Sablone Maria Candida Cesta Alessio Moriconi Andrea Aramini Cinzia Bizzarri Claudia Di Giacinto Rosa Di Bitondo Isabelle Gloaguen Massimiliano Aschi Marcello Crucianelli Riccardo Bertini Marcello Allegretti 《Bioorganic & medicinal chemistry letters》2009,19(15):4026-4030
We reported recently the Structure–Activity Relationship (SAR) of a class of CXCL8 allosteric modulators. They invariably share a 2-arylpropionic moiety so far considered a key structural determinant of the biological activity. We show the results of recent SAR studies on a novel series of phenylacetic derivatives supported by a combined approach of mutagenesis experiments and conformational analysis. The results suggest novel insights on the fine role of the propionic/acetic chain in the modulation of CXCL8 receptors. 相似文献