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71.
C. MIQUEL E. BELLEMAIN C. POILLOT J. BESSIRE A. DURAND P. TABERLET 《Molecular ecology resources》2006,6(4):985-988
In noninvasive studies, the intersample variance in DNA quality and quantity is large, and produces multilocus genotypes of highly variable quality. Here we propose a standardized method for testing the reliability of the genotyping procedure when using the multiple‐tube approach. The quality indexes generated will allow reliable comparisons among samples, loci, studies, and field and/or laboratory protocols. These indexes represent a powerful tool for the quality management of noninvasive studies. 相似文献
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1. Conifer‐feeding budworms (Choristoneura) hibernate in sheltered locations on their host trees from late summer of 1 year to spring of the next. During this period, they do not feed but rely on sustenance provided in the egg. Overwinter survival is dependent on the rate of consumption of these limited reserves. 2. A process model was developed that quantifies the relationship between the rate of consumption and survival at variable temperatures and exposure times for western spruce budworm. The model supported physiological evidence that warm weather conditions early in the diapause period have a dominant influence on overwinter survival. Output compared favourably with field observations of poorer budworm survival at lower elevations where late‐summer and autumn temperatures were warmer compared to those overwintering at cooler, higher elevations. 3. Field experiments demonstrated these weather‐dependent rates of survival were modulated significantly by the degree of shelter experienced by hibernating budworms. 4. Dissection of whole trees harbouring overwintering western spruce budworms showed a significant portion of the population had travelled a considerable distance from the periphery of the tree canopy where eggs were laid to overwinter successfully on the tree bole where sheltered niches are common. 5. Thus, budworms will travel relatively long distances and risk increased mortality during this dispersal to find adequate shelter to overwinter. 相似文献
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KÅRE FOG 《Biological reviews of the Cambridge Philosophical Society》1988,63(3):433-462
(1) N added to decomposing organic matter often has no effect or a negative effect on microbial activity, at least in the long term. More than 60 papers are cited in support of this statement.
(2) The negative effect of N is mainly found with recalcitrant organic matter with a high C/N ratio (straw, wood, etc.), whereas a positive effect of N is common for easily degradable organic material with low C/N ratio.
(3) The negative effect of N could be explained by: (i) N disturbs the outcome of competition between potent and less potent decomposers; (ii) through 'ammonia metabolite repression', N blocks production of certain enzymes, at least in basidiomycetes, and enhances breakdown of the most available cellulose, whereby recalcitrant lignocellulose accumulates; (iii) amino compounds condense with polyphenols and other decomposition products, forming 'browning precursors' which are toxic or inhibitory.
(4) The effect of adding N may depend on the microflora present.
(5) There are indications that some microorganisms have a 'luxury uptake' of N when it is present in sufficient amounts, thereby delaying N mineralization.
(6) The addition of N seems to increase the formation of water-soluble , brown, recalcitrant compounds, but to decrease the amount of humus formed. 相似文献
(2) The negative effect of N is mainly found with recalcitrant organic matter with a high C/N ratio (straw, wood, etc.), whereas a positive effect of N is common for easily degradable organic material with low C/N ratio.
(3) The negative effect of N could be explained by: (i) N disturbs the outcome of competition between potent and less potent decomposers; (ii) through 'ammonia metabolite repression', N blocks production of certain enzymes, at least in basidiomycetes, and enhances breakdown of the most available cellulose, whereby recalcitrant lignocellulose accumulates; (iii) amino compounds condense with polyphenols and other decomposition products, forming 'browning precursors' which are toxic or inhibitory.
(4) The effect of adding N may depend on the microflora present.
(5) There are indications that some microorganisms have a 'luxury uptake' of N when it is present in sufficient amounts, thereby delaying N mineralization.
(6) The addition of N seems to increase the formation of water-soluble , brown, recalcitrant compounds, but to decrease the amount of humus formed. 相似文献
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Theory predicts that lifespan will depend on the dietary intake of an individual, the allocation of resources towards reproduction and the costs imposed by the opposite sex. Although females typically bear the majority of the cost of offspring production, nuptial feeding invertebrates provide an ideal opportunity to examine the extent to which reproductive interactions through gift provisioning impose a cost on males. Here we use experimental evolution in an Australian ground cricket to assess how diet influences male lifespan and how the costs of mating evolve for males. Our findings show that males had significantly shorter lifespans in populations that adapted to a low‐quality diet and that this divergence is driven by evolutionary change in how females interact with males over reproduction. This suggests that the extent of sexual conflict over nuptial feeding may be under‐realized by focusing solely on the consequences of reproductive interactions from the female’s perspective. 相似文献
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代解杰 《中国实验动物学报》2005,(Z1)
[目的]评价抗黄体酮(mifepristone)联合Aromatase抑制剂(letrozole或aminoglutethimide)或iNOS抑制剂(aminoguandine)是否能有效终止恒河猴早期妊娠。[方法]将30只猴子随机分为5组(治疗组每组6只,对照组6只),并在妊娠30,31和32天进行如下处理:对照组,每只动物1ml安慰剂;A组,Mifepristone(1mg/kg,sc.);B组,Mifepristone(sc.)+Letrozole(2.5mg/只sc.);C组,Mifepristone(1mg/kg,sc.)+aminoglute-chimide(50mg/kgsc.,bid);D组,Mifepristone(1mg/kg,sc.)+aminoguanidine(150mg/kg,sc.,bid)。所有妊娠猴在妊娠29天通过超声波确认。[结果]在B、C、D组,所有的动物的妊娠都在妊娠早期被终止(6/6)。A组和对照组的妊娠终止率分别为3/6和2/6。同时,联合用药能够有效排空子宫腔和减少出血。[结论]该处理能有效地终止恒河猴早期妊娠。联合用药比用于女人的妊娠治疗更有效,并减少了流血时间,或许可以代替目前的终止妊娠的医疗方法。 相似文献
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