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191.
Despite being listed as endangered on the IUCN (World Conservation Union) red list [BirdLife International 2005], and intense conservation efforts on its behalf, little is known about the reproductive physiology of the brown kiwi (Apteryx mantelli). This study therefore was undertaken to describe ovarian function in brown kiwi using noninvasive methods that can be utilized in the field. This study describes a simple method for extraction and detection of steroid metabolites in brown kiwi feces by enzyme‐linked immunosorbent assay (ELISA). Average fecal steroid hormone metabolite concentrations were derived from 10 egg‐lay cycles in 2 hens. Testosterone began to increase between 23 and 18 days before oviposition (?23d to ?18d) and remained elevated until just before oviposition. Estradiol rose from ?28d to ?13d and remained elevated until 12 days after oviposition. Progesterone exhibited an increase of short duration from ?8d to +7d with a peak at ?3d. Ovarian follicle growth rate was determined by serial ultrasound measurements of follicles in three habituated female kiwi. Follicle growth rate was described by the formula y=132.54e0.0569x (y=follicle diameter, x=days before oviposition). Follicles ranged in size from 10 to 76 mm. Day of ovulation was estimated using egg yolk size, follicle growth curve, and day of oviposition. This yielded an ovulation‐oviposition cycle length of 7–10 days, significantly shorter than the only other estimate of 16–17 days derived using body weights of a single kiwi hen. The correlation of fecal steroid hormone concentrations with follicle growth provides new insight into the reproductive physiology of the female brown kiwi. Zoo Biol 0:1–10, 2005. © 2005 Wiley‐Liss, Inc.  相似文献   
192.
Summary Within complements the chiasma frequency per chromosome, which directly reflects the amount of recombination, is generally closely correlated with chromosome length, i.e. the chromosomal DNA content. The correlation does not apply when comparisons are made between the complements of different species. Analyses of results from three Angiosperm genera show a progressive decrease in the chiasma frequency per picogram of DNA with increase in nuclear DNA amount.  相似文献   
193.
This review discusses the many roles atomistic computer simulations of macromolecular (for example, protein) receptors and their associated small-molecule ligands can play in drug discovery, including the identification of cryptic or allosteric binding sites, the enhancement of traditional virtual-screening methodologies, and the direct prediction of small-molecule binding energies. The limitations of current simulation methodologies, including the high computational costs and approximations of molecular forces required, are also discussed. With constant improvements in both computer power and algorithm design, the future of computer-aided drug design is promising; molecular dynamics simulations are likely to play an increasingly important role.  相似文献   
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The success of any population translocation programme relies heavily on the measures implemented to control and monitor the spread of disease. Without these measures, programmes run the risk of releasing immunologically naïve species or, more dangerously, introducing novel infectious agents to native populations. As a precaution, a reintroduction programme for the common or hazel dormouse, Muscardinus avellanarius, in England screens dormice before release following captive breeding. Using PCR sequencing of a range of genes, we tested whether the same species of tapeworm(s) were present in captive and free-living dormice. Whilst only Rodentolepis straminea were identified in free-living dormice, cestode ova found in a captive individual produced a molecular match closely related to Hymenolepis microstoma and a previously unrecorded Rodentolepis species. To prevent putting at risk the free-living population, we recommended the continued treatment of dormice showing tapeworm infection before release. Our work demonstrates how molecular techniques can be used to inform reintroduction programmes, reduce risk from disease and increase chances of reintroduction success.

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