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排序方式: 共有844条查询结果,搜索用时 15 毫秒
811.
SC Voss Z Nikolovski PC Bourdon M Alsayrafi YO Schumacher 《Biology of sport / Institute of Sport》2016,33(1):23-28
Leptin and adiponectin play an essential role in energy metabolism. Leptin has also been proposed as a marker for monitoring training load. So far, no studies have investigated the variability of these hormones in athletes and how they are regulated during cumulative exercise. This study monitored leptin and adiponectin in 15 endurance athletes twice daily in the days before, during and after a 9-day simulated cycling stage race. Adiponectin significantly increased during the race (p = 0.001) and recovery periods (p = 0.002) when compared to the baseline, while leptin decreased significantly during the race (p < 0.0001) and returned to baseline levels during the recovery period. Intra-individual variability was substantially lower than inter-individual variability for both hormones (leptin 34.1 vs. 53.5%, adiponectin 19% vs. 37.2%). With regards to exercise, this study demonstrated that with sufficient, sustained energy expenditure, leptin concentrations can decrease within the first 24 hours. Under the investigated conditions there also appears to be an optimal leptin concentration which ensures stable energy homeostasis, as there was no significant decrease over the subsequent race days. In healthy endurance athletes the recovery of leptin takes 48-72 hours and may even show a supercompensation-like effect. For adiponectin, significant increases were observed within 5 days of commencing racing, with these elevated values failing to return to baseline levels after 3 days of recovery. Additionally, when using leptin and adiponectin to monitor training loads, establishing individual threshold values improves their sensitivity. 相似文献
812.
An atlas of the brain of the horseshoe crab Limulus polyphemus is developed. All of the neuronal groups are identified and named, and regions of neuropil are segregated and named where possible. The nomenclature incorporates functionally neutral earlier names and assigns geographical names to newly distinguished structures. The atlas provides a basis for correlating the results of neuroanatomical, neurophysiological, and neurochemical studies, which yield information about individual neurons or groups of neurons in this species. 相似文献
813.
A F Mackintoch M E Crabb R Granger J H Williams D A Chamberlain 《BMJ (Clinical research ed.)》1978,1(6120):1115-1118
In three years 40 patients were resuscitated by ambulancemen after out-of-hospital cardiac arrest and survived to be discharged. Twenty-six of these had had circulatory arrest before an ambulance arrived and a further three had developed ventricular fibrillation before they were moved. Thirty-two patients were alive at the time of review six months to three and a half years later. Resuscitation by ambulancemen can be effective for patients with unheralded sudden cardiac arrest as well as for patients with recent myocardial infarction. Survivors of out-of-hospital ventricular fibrillation may have a favourable long-term prognosis. 相似文献
814.
J R Chamberlain Pagn-Ramos D W Kindelberger D R Engelke 《Nucleic acids research》1996,24(16):3158-3166
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ABSTRACT Understanding den selection for the federally threatened Louisiana black bear (Ursus americanus luteolus) will assist managers in effectively managing bear populations and the landscapes they inhabit. We assessed den selection of 72 female Louisiana black bears at multiple spatial scales in northern and central Louisiana, USA. We used 230 den-years to examine den type preference, microhabitat characteristics of dens, and effects of landscape characteristics on den selection. We also evaluated reuse of tree dens and their availability across several study areas. Bears selected tree dens more frequently (65%) than ground dens. Most (55%) ground dens were associated with standing or downed trees, and most tree dens were in baldcypress (Taxodium distichum; 86%) or surrounded by water (80%). Selection of ground dens was positively associated with landscape metrics related to presence of water, whereas selection of tree dens was positively associated with proximity to edge and greater proportions of swamp and areas containing water. Reuse of tree dens averaged 15% (range = 0–20%) across study areas and our estimates of tree-den availability indicated that tree dens were not a limiting resource for Louisiana black bears in the northern or central portions of Louisiana. Although Louisiana black bears demonstrated plasticity in den selection, we recommend managers use forest management practices that conserve appropriate tree dens and create ground-denning opportunities, because both would promote the recovery of Louisiana black bear populations. 相似文献
818.
Chris L. Gillies James A. Fitzsimons Simon Branigan Lynne Hale Boze Hancock Colin Creighton Heidi Alleway Melanie J. Bishop Simon Brown Dean Chamberlain Ben Cleveland Christine Crawford Matthew Crawford Ben Diggles John R. Ford Paul Hamer Anthony Hart Emma Johnston Tein McDonald Ian McLeod Breanna Pinner Kylie Russell Ross Winstanley 《Ecological Management & Restoration》2015,16(2):84-85
819.
Adam John Baragwanath Mark Christopher Rosamond Andrew James Gallant John Martyn Chamberlain 《Plasmonics (Norwell, Mass.)》2011,6(4):625-636
A qualitative model explaining the extraordinary optical transmission of terahertz (THz) radiation through two-dimensional
periodic arrays of subwavelength apertures is presented. Systematic terahertz time-domain spectroscopy studies have been undertaken
to investigate the combined effects of the lattice arrangement, aperture shape, area and aspect ratio on the transmission
properties of electroformed copper arrays. The extensive results presented provide a unified example of how aperture geometry
dictates SPP activity. The novel fabrication method creates exemplary peak resonances, allowing the onset of surface plasmon
polariton (SPP) decoupling to be distinguished from direct transmission. Furthermore, we provide the first evidence as to
how the temporal properties of SPPs are governed by the single-cycle THz pulse. The time-of-flight model presented can not
only be used to explain the results observed in both the presented and previously published experiments but serves as a method
to engineer specific resonances for sensor applications. 相似文献