997 resultados para T.G. Bright
Resumo:
Demersal fishes hauled up from depth experience rapid decompression. In physoclists, this can cause overexpansion of the swim bladder and resultant injuries to multiple organs (barotrauma), including severe exophthalmia (pop-eye). Before release, fishes can also be subjected to asphyxia and exposure to direct sunlight. Little is known, however, about possible sensory deficits resulting from the events accompanying capture. To address this issue, electroretinography was used to measure the changes in retinal light sensitivity, flicker fusion frequency, and spectral sensitivity in black rockfish (Sebastes melanops) subjected to rapid decompression (from 4 atmospheres absolute [ATA] to 1 ATA) and Pacific halibut (Hippoglossus stenolepis) exposed to 15 minutes of simulated sunlight. Rapid decompression had no measurable influence on retinal function in black rockfish. In contrast, exposure to bright light significantly reduced retinal light sensitivity of Pacific halibut, predominately by affecting the photopigment which absorbs the green wavelengths of light (520580 nm) most strongly. This detriment is likely to have severe consequences for postrelease foraging success in green-wavelength-dominated coastal waters. The visual system of Pacific halibut has characteristics typical of species adapted to low light environments, and these characteristics may underlie their vulnerability to injury from exposure to bright light.
Resumo:
A adiponectina, um hormnio produzido pelo tecido adiposo, atua na regulao do metabolismo energtico e interfere favoravelmente na sensibilidade insulina atravs de suas aes no fgado e musculatura esqueltica. Ao contrrio da maioria das outras adipocitocinas, associa-se inversamente com a obesidade visceral, resistncia insulina, diabetes tipo 2 e doena cardiovascular. Inmeros estudos demonstraram nos ltimos anos os efeitos de variantes genticas no gene ADIPOQ sobre os nveis circulantes de adiponectina, resistncia insulina, diabetes e obesidade. Entretanto, alm de resultados contraditrios, a maior parte desses estudos foi realizada em populaes Caucasianas e Asiticas. Avaliar, em uma populao multitnica adulta do municpio do Rio de Janeiro, as possveis associaes das variantes genticas (-11391 G>A, -11377C>G, +45T>G e T517G) no gene ADIPOQ com o fentipo obeso, nveis circulantes de adiponectina de alto peso molecular e fatores de risco cardiometablico. Trata-se de um estudo transversal. Foram estudados 100 indivduos eutrficos (IMC 18,5 24,9 kg/m2, idade: 32,5 + 9,8 anos) e 100 obesos (IMC 30 58,2 kg/m2, idade 37,5 + 14,1 anos), igualmente divididos entre homens e mulheres. Os indivduos obesos apresentaram valores significativamente maiores de circunferncia abdominal, presso arterial sistlica, diastlica e mdia, glicemia de jejum, triglicerdeos, LDL-colesterol, leptina, insulina, HOMA-IR e protena C reativa, quando comparados aos eutrficos. Contrariamente, exibiram menores valores de adiponectina e HDL-colesterol. Anlises de correlao mostraram relao inversa e significativa entre a adiponectina, circunferncia abdominal, insulina, HOMA-IR e presso arterial. Com os nveis de HDL-colesterol, a correlao foi positiva. Por meio de anlise de regresso mltipla foi possvel identificar os determinantes dos nveis sricos de adiponecinta. Sexo masculino, circunferncia abdominal, HOMA-IR e a variante gentica -11391G>A, foram os principais responsveis por essa variao, com um R2 de 30%. Quanto anlise gentica, no encontramos nenhuma associao entre essas variantes e o fentipo obeso. Entretanto, os indivduos carreadores do alelo mutante -11391A apresentaram menores valores de glicemia, presso arterial e relao cintura-quadril e maiores concentraes sanguneas de adiponectina, quando comparados aos indivduos ditos selvagens. Ademais, os carreadores do alelo mutante -11377G apresentaram menores valores de presso arterial sistlica, diastlica e mdia. Os resultados do presente estudo demonstram que nveis de adiponectina diferem entre eutrficos e obesos e que concentraes mais baixas dessa adipocitocina esto associadas a um pior perfil cardiometablico. Variantes no gene ADIPOQ podem interferir nessa relao e alguns polimorfismos parecem ter um perfil protetor no risco cardiovascular.
Resumo:
Interest in development of offshore renewable energy facilities has led to a need for high-quality, statistically robust information on marine wildlife distributions. A practical approach is described to estimate the amount of sampling effort required to have sufficient statistical power to identify species specific hotspots and coldspots of marine bird abundance and occurrence in an offshore environment divided into discrete spatial units (e.g., lease blocks), where hotspots and coldspots are defined relative to a reference (e.g., regional) mean abundance and/or occurrence probability for each species of interest. For example, a location with average abundance or occurrence that is three times larger the mean (3x effect size) could be defined as a hotspot, and a location that is three times smaller than the mean (1/3x effect size) as a coldspot. The choice of the effect size used to define hot and coldspots will generally depend on a combination of ecological and regulatory considerations. A method is also developed for testing the statistical significance of possible hotspots and coldspots. Both methods are illustrated with historical seabird survey data from the USGS Avian Compendium Database.
