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1.
Mar Pollut Bull ; 145: 396-406, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31590802

RESUMEN

We determined depth profiles of total mercury (T-Hg) in six 210Pb-dated sediment cores from Todos os Santos Bay to reconstruct the history of anthropogenic Hg accumulation. We also assessed superficial sediments samples from five estuaries. T-Hg concentrations (5-3500 µg kg-1) presented a large spatial and temporal variability. T-Hg concentrations in Ribeira Bay increased up to 200-fold along time, whereas the fluxes of T-Hg are substantially higher (up to 10,000 fold) than present-day wet deposition for industrialized areas. Sedimentary records indicate that a chlor-alkali plant has been the main source of Hg pollution until the present, although the T-Hg records suggest that harbor, shrimp farming, and oil refinery activities, besides Hg atmospheric depositions, are important across the bay. Sediments in the Ribeira Bay act as an important Hg sink. If sediments are eroded or disturbed, they may release Hg, thus posing a serious risk to wildlife and ecosystem health. CAPSULE: Sedimentary cores provide data on preindustrial levels and also anthropogenic fluxes of Hg for the appraisal of the magnitude, processes and potential risks of the contamination.


Asunto(s)
Sedimentos Geológicos , Actividades Humanas/historia , Mercurio/análisis , Contaminantes Químicos del Agua/historia , Bahías , Brasil , Ecosistema , Monitoreo del Ambiente , Contaminación Ambiental/historia , Historia del Siglo XX , Historia del Siglo XXI , Humanos , Contaminantes Químicos del Agua/análisis
2.
Braz. j. biol ; 79(2): 263-272, Apr.-June 2019. tab, graf
Artículo en Inglés | LILACS | ID: biblio-989458

RESUMEN

Abstract The distribution of most species occurs in delimited regions with unique characteristics called "centers of endemism". In Eastern Amazon is located the Belém Endemism Center (BEC), one of the most intensely deforested in Brazilian Amazon. Here, we show information about orchid bee assemblages based on historical records from entomological collections. For each species, we calculated occurrence frequency and dominance, and we classified them in 3 statuses: common, intermediate or rare species. Curves of observed and estimated richness were built, based on Jackknife estimator. We found 1,257 specimens from 56 species, constituting records from 1917 to 2009, and one species is a new record for BEC. Higher number of specimens and species was concentrated in a few locations and surveys increased from the 70's. The results suggest a high richness of orchid bees in the BEC, although this scenario is far from what is expected for the entire area. The high occurrence of rare species may be related to their low representativeness in the collections, and the proximity between the areas had favored samplings. Even so, the species list and the conservation status presented here may be useful information in studies comparing past and current orchid bee fauna, and, allied to data on bees' responses to land use changes occurred in BEC over the years, can fit as a basis for defining priority areas for conservation.


Resumo A distribuição da maioria das espécies ocorre em regiões delimitadas com características únicas conhecidas como "centros de endemismo". Na Amazônia Oriental está localizado o Centro de Endemismo Belém (CEB), uma das áreas mais intensivamente desmatadas na Amazônia Brasileira. Aqui, apresentamos informações sobre assembleias de abelhas orquídeas baseadas em registros históricos de coleções entomológicas. Para cada espécie, foram calculadas a frequência de ocorrência e a dominância, classificando-as em 3 estados: espécies comuns, intermediárias ou raras. Foram geradas curvas de riqueza observada e estimada, com base no estimador Jackknife. Encontramos 1.257 espécimes de 56 espécies, constituindo registros de 1917 a 2009, e uma espécie é um novo registro no CEB. Maior número de espécimes e espécies foi concentrado em poucos locais, com intensificação nas coletas a partir dos anos70. Os resultados sugerem alta riqueza de abelhas orquídeas no CEB, embora esse cenário esteja longe do que é esperado para toda a área. A elevada ocorrência de espécies raras pode estar relacionada à baixa representatividade nas coleções e a proximidade entre as áreas favoreceu as amostragens. Mesmo assim, a lista de espécies e o estado de conservação aqui apresentados podem ser informações úteis em estudos interessados em comparar a fauna passada e atual de abelhas das orquídeas e, aliado a dados sobre as respostas das abelhas às mudanças de uso da terra ocorridas no CEB ao longo dos anos, podem servir de base para definição de áreas prioritárias para conservação.


Asunto(s)
Animales , Historia del Siglo XX , Historia del Siglo XXI , Abejas/clasificación , Abejas/fisiología , Brasil , Especies en Peligro de Extinción , Conservación de los Recursos Naturales
3.
Braz J Biol ; 79(2): 263-272, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30110081

RESUMEN

The distribution of most species occurs in delimited regions with unique characteristics called "centers of endemism". In Eastern Amazon is located the Belém Endemism Center (BEC), one of the most intensely deforested in Brazilian Amazon. Here, we show information about orchid bee assemblages based on historical records from entomological collections. For each species, we calculated occurrence frequency and dominance, and we classified them in 3 statuses: common, intermediate or rare species. Curves of observed and estimated richness were built, based on Jackknife estimator. We found 1,257 specimens from 56 species, constituting records from 1917 to 2009, and one species is a new record for BEC. Higher number of specimens and species was concentrated in a few locations and surveys increased from the 70's. The results suggest a high richness of orchid bees in the BEC, although this scenario is far from what is expected for the entire area. The high occurrence of rare species may be related to their low representativeness in the collections, and the proximity between the areas had favored samplings. Even so, the species list and the conservation status presented here may be useful information in studies comparing past and current orchid bee fauna, and, allied to data on bees' responses to land use changes occurred in BEC over the years, can fit as a basis for defining priority areas for conservation.


Asunto(s)
Abejas , Animales , Abejas/clasificación , Abejas/fisiología , Brasil , Conservación de los Recursos Naturales , Especies en Peligro de Extinción , Historia del Siglo XX , Historia del Siglo XXI
4.
J Anim Sci ; 96(8): 3381-3397, 2018 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-29767729

RESUMEN

The main objective of this study was to establish a protocol to validate urine spot samples to estimate N excretion and microbial synthesis in goat and sheep; and to study factors that affect daily creatinine and purine derivatives (PD) urinary excretion. Also a performance trial was carried out to compare goat and sheep slaughtered after different feedlot periods. Twelve Boer goats (20.6 kg ± 3.4 initial BW) and 12 Dorper sheep (18.4 kg ± 2.3 initial BW), all 4-mo-old, males, were used. Eight animals (4 goats and 4 sheep) were randomly allocated to be slaughtered at 28, 56, and 84 d in feedlot. The experiment was conducted in a completely randomized design in a 2 × 3 factorial scheme, in which the factors were both species and the 3 feedlot periods. Diet consisted of 50% sorghum silage and 50% concentrate on a DM basis. Nutrient intake was higher (P < 0.01) for sheep than goats. Apparent digestibility of nutrients was similar (P > 0.05) in both species. Sheep had greater (P < 0.01) ADG and final BW than goats. Fat deposition and fat:muscle ratio was higher (P < 0.01) in sheep carcasses. Sheep had higher N urinary (P = 0.02) excretion and N retention (g/d; P < 0.01) than goats. Urinary N excretion increased linearly (P < 0.01) in response to feedlot period. However, feedlot did not affect (P = 0.20) N retention, but linearly reduced the relationship between N retained and ingested (P = 0.04) or apparently digested (P < 0.01). Microbial efficiency (P > 0.05) did not differ between species. Creatinine excretion (C mg/d; P < 0.01) was higher in sheep than goats. Purine derivatives (Y) were related closely with OM intake (Y = 0.013±0.0007X; r2 = 94). A difference (P < 0.01) was found between the allometric model for creatinine excretion (Y) and muscle weight (X) for both species, and the following equations were obtained: Y = 89.04(±31.44)X0.9797(±0.16) for goats and Y = 109.8(±47.50)X0.8002(±0.20) for sheep. Creatinine concentration was greater during nocturnal than diurnal periods, with lower diurnal fluctuations. Sampling time did not affect (P = 0.27) the PD:C ratio. The urea (U):C ratio was higher (P < 0.01) in sheep than goats, and was also higher (P < 0.01) during diurnal than nocturnal sampling periods. Our results suggest that it is necessary to take 2 and 3 spot urine samples after feeding to estimate N compounds excretions in goats and sheep, respectively.


Asunto(s)
Alimentación Animal/análisis , Cabras/fisiología , Estado Nutricional , Proteínas/metabolismo , Ovinos/fisiología , Animales , Dieta/veterinaria , Ingestión de Alimentos , Grano Comestible , Masculino , Nitrógeno/metabolismo , Distribución Aleatoria , Rumen/metabolismo , Ensilaje/análisis , Sorghum , Urea/química , Urea/orina
5.
J Aging Phys Act ; 21(3): 241-59, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22952201

RESUMEN

Few studies have evaluated the benefit of providing exercise to underprivileged older adults at risk for falls. Economically and educationally disadvantaged older adults with previous falls (mean age 79.06, SD = 4.55) were randomized to 4 mo of multimodal exercise provided as fully supervised center-based (FS, n = 45), minimally supervised home-based (MS, n = 42), or to nonexercise controls (C, n = 32). Comparing groups on the mean change in fall-relevant mobility task performance between baseline and 4 mo and compared with the change in C, both FS and MS had significantly greater reduction in timed up-and-go, F(2,73) = 5.82, p = .004, η2 p = .14, and increase in tandem-walk speed, F(2,73) = 7.71, p < .001 η2 p = .17. Change in performance did not statistically differ between FS and MS. In community-dwelling economically and educationally disadvantaged older adults with a history of falls, minimally supervised home-based and fully supervised center-based exercise programs may be equally effective in improving fall-relevant functional mobility.


Asunto(s)
Accidentes por Caídas/prevención & control , Terapia por Ejercicio/métodos , Actividades Cotidianas , Anciano , Análisis de Varianza , Estudios de Casos y Controles , Distribución de Chi-Cuadrado , Escolaridad , Femenino , Humanos , Renta/estadística & datos numéricos , Entrevistas como Asunto , Masculino , Equilibrio Postural , Estadísticas no Paramétricas , Resultado del Tratamiento , Poblaciones Vulnerables
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