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排序方式: 共有82条查询结果,搜索用时 15 毫秒
1.
Kevin E. Doherty Jeffrey S. Evans Johann Walker James H. Devries David W. Howerter 《PloS one》2015,10(2)
We used publically available data on duck breeding distribution and recently compiled geospatial data on upland habitat and environmental conditions to develop a spatially explicit model of breeding duck populations across the entire Prairie Pothole Region (PPR). Our spatial population models were able to identify key areas for duck conservation across the PPR and predict between 62.1 – 79.1% (68.4% avg.) of the variation in duck counts by year from 2002 – 2010. The median difference in observed vs. predicted duck counts at a transect segment level was 4.6 ducks. Our models are the first seamless spatially explicit models of waterfowl abundance across the entire PPR and represent an initial step toward joint conservation planning between Prairie Pothole and Prairie Habitat Joint Ventures. Our work demonstrates that when spatial and temporal variation for highly mobile birds is incorporated into conservation planning it will likely increase the habitat area required to support defined population goals. A major goal of the current North American Waterfowl Management Plan and subsequent action plan is the linking of harvest and habitat management. We contend incorporation of spatial aspects will increase the likelihood of coherent joint harvest and habitat management decisions. Our results show at a minimum, it is possible to produce spatially explicit waterfowl abundance models that when summed across survey strata will produce similar strata level population estimates as the design-based Waterfowl Breeding Pair and Habitat Survey (r2 = 0.977). This is important because these design-based population estimates are currently used to set duck harvest regulations and to set duck population and habitat goals for the North American Waterfowl Management Plan. We hope this effort generates discussion on the important linkages between spatial and temporal variation in population size, and distribution relative to habitat quantity and quality when linking habitat and population goals across this important region. 相似文献
2.
Tarnopolsky MA Rennie CD Robertshaw HA Fedak-Tarnopolsky SN Devries MC Hamadeh MJ 《American journal of physiology. Regulatory, integrative and comparative physiology》2007,292(3):R1271-R1278
Impaired mitochondrial function and structure and intramyocellular lipid (IMCL) accumulation have been associated with obesity and Type 2 diabetes. We examined whether endurance exercise training and sex influenced IMCL and mitochondrial morphology using electron microscopy, whole-body substrate use, and mitochondrial enzyme activity. Untrained men (n = 5) and women (n = 7) were tested before and after 7 wk of endurance exercise training. Testing included 90 min of cycle ergometry at 60% Vo(2 peak) with preexercise muscle biopsies analyzed for IMCL and mitochondrial size/area using electron microscopy and short-chain beta-hydroxyacyl-CoA dehydrogenase (SCHAD) and citrate synthase (CS) enzyme activity. Training increased the mean lipid area density (P = 0.090), the number of IMCL droplets (P = 0.055), the number of IMCL droplets in contact with mitochondria (P = 0.010), the total mitochondrial area (P < 0.001), and the size of individual mitochondrial fragments (P = 0.006). Women had higher mean lipid area density (P = 0.030) and number of IMCL droplets (P = 0.002) before and after training, but higher individual IMCL area only before training (P = 0.013), compared with men. Women oxidized more fat (P = 0.027) and less carbohydrate (P = 0.032) throughout the study. Training increased Vo(2 peak) (P < 0.001), %fat oxidation (P = 0.018), SCHAD activity (P = 0.003), and CS activity (P = 0.042). In summary, endurance exercise training increased IMCL area density due to an increase in the number of lipid droplets, whereas the increase in total mitochondrial area was due to an increase in the size of individual mitochondrial fragments. In addition, women have higher IMCL content compared with men due mainly to a greater number of individual droplets. Finally, endurance exercise training increased the proportion of IMCL in physical contact with mitochondria. 相似文献
3.
Kang Yun Hee Ji Na Young Lee Chung Il Lee Hee Gu Kim Jae Wha Yeom Young IL Kim Dae Ghon Yoon Seung Kew Kim Jong Wan Park Pil Je Song Eun Young 《Amino acids》2011,40(3):1003-1013
Amino Acids - Endothelial cell-specific molecule-1 (ESM-1) is a secretory proteoglycan comprising a mature polypeptide of 165 amino acids and a single dermatan sulfate. The aim of this study was to... 相似文献
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P. J. Devries G. O. Poinar 《Proceedings. Biological sciences / The Royal Society》1997,264(1385):1137-1140
Although symbiotic association with ants is pervasive in the butterfly families Lycaenidae and Riodinidae the age of these symbioses has never been estimated explicitly. Here we report the first known fossil riodinid caterpillar. This fossil can be dated minimally between 15 and 20 Ma old, and confidently placed in the extant genus Theope. Differing little from modern day Theope, this fossil from Dominican amber provides direct evidence that secretory and acoustical organs used by modern caterpillars to mediate symbioses with ants have been highly developed at least since the Miocene. This fossil therefore becomes the point of reference for future studies using molecular clock methods for dating these symbioses within the riodinid butterflies. Modern evidence, and the abundance of dolichoderine ants in Dominican amber (now extinct in the West Indies) imply that specialized symbiotic relationships between Theope caterpillars and these ants were likely in existence at least 15 Ma ago. The current distribution of neotropical riodinid butterfly and ant faunas indicates the extinction in the West Indies of at least two unrelated taxa that formed a tightly linked symbiotic association, which persisted to the present elsewhere. <br> 相似文献
6.
Hea Jin Ryu Ji-Eun Kim Yeon-Joo Kim Ji-Yang Kim Won IL Kim So-Yeon Choi Min-Ju Kim Tae-Cheon Kang 《Cellular and molecular neurobiology》2013,33(4):575-585
Transient receptor potential canonical channel (TRPC) is a nonselective cation channel permeable to Ca2+, which express in many cell types, including neurons. However the alterations in TRPC receptor expressions in response to status epilepticus (SE) have not been explored. Therefore, the present study was designated to elucidate the roles of TRPC3 in neuronal death and vasogenic edema within the rat piriform cortex (PC) following SE. In non-SE animals, TRPC3 immunoreactivity was abundantly detected in the PC. Following SE, TRPC3 immunoreactivity was increased in neurons. Furthermore, TRPC3 expression was detected in endothelial cells that did not contain it in non-SE animals. Loss of SMI-71 (a blood–brain barrier antigen) immunoreactivity was also observed in TRPC3 positive endothelial cells. In addition, FJB positive neurons and vasogenic edema were noticeably detected in the PC. To directly determine whether TRPC3 activation is correlated to SE-induced vasogenic edema formation and neuronal damages in the PC, the effect of Pyr-3 (a TRPC3 antagonist) on SE-induced insults were investigated. Pyr-3 infusion effectively attenuated vasogenic edema in the PC as compared to the vehicle. Therefore, our findings indicate that TRPC3 activation/overexpression induced by SE may involve BBB disruption and neuronal damages in the rat PC following SE. Therefore, the present study was TRPC3 may play an important role in SE-induced vasogenic edema formation through BBB disruptions in the rat PC. 相似文献
7.
Olendzenski L Liu L Zhaxybayeva O Murphey R Shin DG Gogarten JP 《Journal of molecular evolution》2000,51(6):587-599
Members of the Deinococcaceae (e.g., Thermus, Meiothermus, Deinococcus) contain A/V-ATPases typically found in Archaea or Eukaryotes which were probably acquired by horizontal gene transfer. Two methods were used to quantify the extent to which archaeal or eukaryotic genes have been acquired by this lineage. Screening of a Meiothermus ruber library with probes made against Thermoplasma acidophilum DNA yielded a number of clones which hybridized more strongly than background. One of these contained the prolyl tRNA synthetase (RS) gene. Phylogenetic analysis shows the M. ruber and D. radiodurans prolyl RS to be more closely related to archaeal and eukaryal forms of this gene than to the typical bacterial type. Using a bioinformatics approach, putative open reading frames (ORFs) from the prerelease version of the D. radiodurans genome were screened for genes more closely related to archaeal or eukaryotic genes. Putative ORFs were searched against representative genomes from each of the three domains using automated BLAST. ORFs showing the highest matches against archaeal and eukaryotic genes were collected and ranked. Among the top-ranked hits were the A/V-ATPase catalytic and noncatalytic subunits and the prolyl RS genes. Using phylogenetic methods, ORFs were analyzed and trees assessed for evidence of horizontal gene transfer. Of the 45 genes examined, 20 showed topologies in which D. radiodurans homologues clearly group with eukaryotic or archaeal homologues, and 17 additional trees were found to show probable evidence of horizontal gene transfer. Compared to the total number of ORFs in the genome, those that can be identified as having been acquired from Archaea or Eukaryotes are relatively few (approximately 1%), suggesting that interdomain transfer is rare. 相似文献
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Renal glomerular evolution in Antarctic notothenioid fishes 总被引:2,自引:0,他引:2
Light and electron microscopy were used to document the degree of glomerular development in 10 species of Antarctic notothenioid fishes. When combined with results of previous studies, data revealed that 16 of 20 species inhabiting subzero sea water were aglomerular. One subantarctic and two temperate species were pauciglomerular, and an additional temperate species had a moderate number of glomeruli. Renal corpuscles were variable in number and diameter among the pauciglomerular species, and most had few patent glomerular capillaries. Radiolabelled markers indicated that the glomerular filtration rate was low in the pauciglomerular Notothenia angustata , ranging from 0.005 to 0.124 ml h−1 kg−1 in eight specimens. Arterial perfusion of Microfil demonstrated that arteries supplying aglomerular and pauciglomerular kidneys were confined largely to the periphery of the organ, and glomerular capillaries were absent or few in number. As ancestral notothenioids probably had glomerular kidneys, data from 20–25% of the fauna suggest that there has been an evolutionary loss of glomeruli in many species. The pattern of glomerular reduction is consistent with the hypothesis that the selective advantage of aglomerularism is in the urinary conservation of small molecular weight antifreeze glycopeptide compounds that are vital to survival in sub-zero Antarctic waters. 相似文献
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