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71.
David E. Ausband Michael S. Mitchell Sarah B. Bassing Andrea Morehouse Douglas W. Smith Daniel Stahler Jennifer Struthers 《Ethology : formerly Zeitschrift fur Tierpsychologie》2016,122(12):963-972
Variation in group composition and environment can affect helping behavior in cooperative breeders. Understanding of how group size, traits of individuals within groups, food abundance, and predation risk simultaneously influence helping behavior is limited. We evaluated pup‐guarding behavior in gray wolves (Canis lupus) to assess how differences in individuals, groups, and environment affect helping behavior. We used data from 92 GPS‐collared wolves in North America (2001–2012) to estimate individual pup‐guarding rates. Individuals in groups with low helper‐to‐pup ratios spent more time guarding young than those in groups with more helpers, an indication of load‐lightening. Female helpers guarded more than male helpers, but this relationship weakened as pups grew. Subset analyses including data on helper age and wolf and prey density showed such factors did not significantly influence pup‐guarding rates. We show that characteristics of individuals and groups have strong influences on pup‐guarding behavior in gray wolves, but environmental factors such as food abundance and predation risk from conspecifics were not influential. 相似文献
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Twenty-two salmon smolts, Salmo salar L., carrying miniature sonic tags were tracked individually for periods of up to 175 h in Loch Voil, Scotland, during May 1979 and 1980. Activity was predominantly nocturnal, 80% occurring between 21.00 and 06.00 hours, and was apparently undirected. Average velocities during this active interval were 0.6 body lengths per second (bl s−1 ), with 98 and 93% of the time spent moving at less than 2 and less than 1 bl s−1 , respectively. The rates of downstream displacement were 0.04 bl s−1 in 1979 and 0.01 bl s−1 in 1980. The direction of displacement of smolts and of movement of water at a depth of 1 m was positively correlated ( P <0.001) and smolt displacement was biassed slightly ahead of water movement. Mean step lengths were 141 and 200 m in 1979 and 1980, respectively. Rates of downstream passage of 327 ICES plate-tagged smolts released 16.8 km upstream of the fish trap at Clunie dam, Loch Tummel, during the spring migrations of 1975 and 1976 averaged 0.13 bl s−1 in each year: net surface water movement was about 3.7 times this rate during the same intervals. These data are consistent with the model of passive smolt migration postulated by Tytler et al. (1978) and suggest that the active component required to ensure passage through a loch (Thorpe & Morgan, 1978) is very small. 相似文献
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R. G. Luke A. C. Kennedy J. D. Briggs N. W. Struthers W. Barr Stirling 《BMJ (Clinical research ed.)》1968,3(5621):764-768
Nephrectomy has been carried out in 34 patients with hypertension associated with unilateral parenchymal renal disease (28 with unilateral pyelonephritis, 3 tuberculosis, 2 hypoplasia, and 1 adenocarcinoma). In 13 of the patients the blood pressure was corrected, in four it was improved, and in 17 it was unaffected. The intravenous pyelogram (by the infusion technique with nephrotomography if necessary) and renogram give adequate information in most patients with unilateral parenchymal renal disease but may need to be supplemented by aortography, or retrograde pyelography, or divided renal function studies in a few special circumstances. When the function of the damaged kidney is less than 25% of the total (which is well maintained), and the contralateral kidney is intact, nephrectomy is recommended provided the hypertension is significant; success is more likely in younger patients with a short history of hypertension. 相似文献
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Stephen D. Goble Liping Wang K. Lulu Howell Alka Bansal Richard Berger Linda Brockunier Jerry DiSalvo Scott Feighner Bart Harper Jiafang He Amanda Hurley Donna Hreniuk Emma Parmee Michael Robbins Gino Salituro Anthony Sanfiz Eric Streckfuss Eloisa Watkins Ann E. Weber Mary Struthers Scott D. Edmondson 《Bioorganic & medicinal chemistry letters》2010,20(6):1895-1899
A series of amide derived β3-adrenergic receptor (AR) agonists is described. The discovery and optimization of several series of compounds derived from 1, is used to lay the SAR foundation for second generation β3-AR agonists for the treatment of overactive bladder. 相似文献