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Harold L. PrattJr Theo C. Pratt Danielle Morley Susan Lowerre-Barbieri Angela Collins Jeffrey C. Carrier Kristen M. Hart Nicholas M. Whitney 《Environmental Biology of Fishes》2018,101(4):515-530
Nurse sharks have not previously been known to migrate. Nurse sharks of the Dry Tortugas (DRTO) mating population have a highly predictable periodic residency cycle, returning to the Dry Tortugas Courtship and Mating Ground (DTCMG) annually (males) or bi- to triennially (females) during the June/July mating season. For 23 years we have followed the movements of 76 recaptured adults of a total of 115 tagged adults. Telemetry detections of 40 females tagged with acoustic transmitters show that most tagged and presumably post-partum females are continuously present in the DRTO in the fall, winter and early spring following the June mating season but these females depart in late March to early May. Detections reveal these females avoid the DTCMG completely during the next mating season, returning from late summer to fall. Telemetry records of nine of 17 adult males that co-habited with these females in the DTCMG depart DRTO waters every July. Both sexes may overwinter in the DRTO. Between 2011 and 2016 three males and five females with transmitters were detected to move up the west coast of Florida outside of the mating season as far north as the waters off Tampa Bay (335 km). Six others were only detected in the lower Florida Keys (292 km). Nine sharks returned to DRTO; one returned six times. Some overwintered and some resumed courtship in June, demonstrating both resident and migratory contingents within their population, partial migration and an ability to navigate with high spatial and temporal precision. 相似文献
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Lydia Katsis Pamela M. K. Cunneyworth Katy M. E. Turner Andrea Presotto 《International journal of primatology》2018,39(4):493-510
Electrocution from power infrastructure threatens many primate species, yet knowledge of effective evidence-based mitigation strategies is limited. Mitigation planning requires an understanding of the spatial distribution of electrocutions to prioritize high-risk areas. In Diani, a coastal Kenyan town, electrocution is an important cause of death for five primate species. In this study we aim to describe the spatial patterns of electrocutions and electric shock incidents (collectively referred to as electrocutions hereafter) and identify electrocution hotspots to guide an effective primate conservation approach in Diani. Colobus Conservation, a not-for-profit organization, has recorded electrocutions and annual primate census data since 1998. We georeferenced 329 electrocution data points and analyzed them using QGIS. We identified and compared hotspots across species, seasons, and time using kernel density estimation and Getis-Ord-Gi*. We employed spatial regression models to test whether primate population density and power line density predicted the location of electrocution hotspots. Electrocutions occurred in hotspots that showed little variation in location between species and seasons. The limited variation in hotspot location over time likely occurred as a result of new building development in Diani and variability in primate detection rates by community members. Primate density and power line density were significant predictors of electrocution density for Angolan black-and-white colobus (Colobus angolensis palliatus) and Sykes monkeys (Cercopithecus mitis albogularis), but the relationship was weak, suggesting the presence of additional risk factors. This study provides a framework for systematic spatial prioritization of power lines that can be used to reduce primate electrocutions in Diani, and can be adopted in other areas of the world where primates are at risk from electrocution. 相似文献
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John Matsoukas Morley D. Hollenberg Thomas Mavromoustakos Dimitris Panagiotopoulos Kostas Alexopoulos Raguav Yamdagni Qiao Wu Graham J. Moore 《Journal of Protein Chemistry》1997,16(2):113-131
The conformational properties of the pentapeptide Ser-Phe-Leu-Leu-Arg (P5), a human thrombin receptor-derived sequence forming part of a tethered ligand which activates the thrombin receptor, and its more active amide derivative Ser-Phe-Leu-Leu-Arg-NH2 (P5-NH2), have been studied by proton NMR spectroscopy in dimethylsulfoxide. Measurements of nuclear Overhauser effects, performed using two-dimensional rotating frame nuclear Overhauser (ROESY) and one-dimensional nuclear Overhauser enhancement (NOE) spectroscopy, revealed that P5 exists mainly in an extended conformation. However, proton–proton 1D-NOEs between Phe CH and Ser CH, Leu3 CH and Leu3 NH, and Leu4 CH and Leu4 NH, as well as between the Ser and Arg sidechains, also implicated a minor conformer for P5 having a curved backbone and a near-cyclic structure. In contrast to P5, measurements of NOEs and ROEs for P5-NH2 revealed a more stabilized cyclic structure which may account for its higher biological potency. Thus strong interresidue sequential NH (i)–NH (i + 1) interactions, as well as C-terminal carboxamide to N-terminal side-chain interactions, i.e., Arg CONH2 to Phe ring and Arg CONH2 to Ser
, observed at lower levels of the ROESY spectrum, supported a curved backbone structure for SFLLR-NH2. Since the higher potaency P5-NH2 analogue adopts predominantly a cyclic structure, a cyclic bioactive conformation for thrombin receptor agonist peptides is suggested. 相似文献
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John P. MacManus Ingrid Rasquinha Marsha A. Black Nicole B. Laferriere Robert Monette Teena Walker Paul Morley 《Experimental cell research》1997,233(2):310
The alkaloid protein kinase inhibitor staurosporine induced neuronal cell death with both the morphological and the biochemical characteristics of apoptosis. The punctate chromatin associated with apoptosis with retention of plasma membrane integrity was observed in neurons identified by colocalization of NeuN staining. Such cells had DNA fragmentation visualized byin situend-labeling which was seen as a laddered pattern upon gel electrophoresis. In contrast cells treated with glutamate did not exhibit either of these morphological or biochemical hallmarks of apoptosis. Instead a much smaller and more compact pyknotic structure was observed associated with smeared DNA fragmentation patterns. A confocal time-lapse study of the appearance of the morphological changes in individual nuclei after staurosporine treatment showed collapse into punctate chromatin over a period of 10 min. In contrast, the collapse into small pyknotic nuclei after glutamate treatment was at least 10 times slower. It is concluded that excitotoxicity produced by glutamate did not induce cell death by an apoptotic mechanism in cultured cortical neurons. 相似文献