Efeito da somatotropina bovina recombinante (bst) sobre a produção de leite de cabras Saanen e Anglo Nubiana.

O presente trabalho, realizado na Embrapa Caprinos, Sobral-CE, avaliou o efeito da somatotropina bovina recombinante (bST) sobre a produção de leite de cabras Saanen e Anglo Nubiana, recebendo dois níveis de concentrado. Foram usadas 30 cabras, entre a segunda e quarta ordem de parição, divididas em dois grupos, de acordo com a quantidade de concentrado fornecida: 1,0 kg/animal/dia e 1,25 kg/animal/dia. Cada grupo foi subdividido em dois tratamentos, sendo fornecido 0 mg/kg.PV e 3,0 mg/kg.PV de bST. As análises estatísticas foram realizadas por meio do procedimento GLM, utilizando o modelo que incluiu os efeitos fixos de raça, níveis de concentrado, interação raça x níveis de concentrado, bST e suas interações e a variável dia de lactação (efeitos linear e quadrático). Houve efeito (P<0,01) de raça, níveis de concentrado e da aplicação do bST sobre a produção de leite, sendo significativa (P<0,01) apenas a interação raça x níveis de concentrado. A produção de leite foi maior (P<0,05) para a Saanen em relação a Anglo Nubiana apenas no tratamento com menor nível de concentrado. Para a Anglo Nubiana, a quantidade de concentrado fornecida afetou (P<0,05) a produção de leite. A produção de leite aumentou (P<0,05) com a aplicação de bST, de 1,73 kg/aniamal/dia para 2,04 kg/animal/dia. Conclui-se, portanto, que a produção de leite de cabras Saanen e Anglo Nubiana pode ser incrementada com a aplicação de bST. Effect of recombinant bovine somatotropin (bst) on milk production of Saanen and Anglo-Nnubian goats. Abstract: This work was carried out at Embrapa Caprinos, in Sobral, Ceará, to evaluate the effect of recombinant bovine somatotropin (bST) on milk production of Saanen ang Anglo-Nubian goats fed two levels of concentrate. Thirty animals, between the second and the fouth parturition order, were divided into two groups according with the the amount of concentrate: 1 kg/animal/day and 1.25 kg/animal/day. Each group was splited in two treatments, being fed 0 mg/kg BW and 3mg/kg BW of bST. Statistical analysis were done by GLM procedure, by utilizing a model which included the fixed effects of breeds, levels of concentrate, interactions of breeds and levels of concentrate, bST and its interactions, and the variable days of lactation (linear and squared effects). It was found effect (P<0.01) of breed, levels of concentrate and application of bST on milk production, being signifficant (P<0.01) only the interaction breed x levels of concentrate. Milk production was higher (P<0.05) for Saanen in relation to Anglo-Nubian only in the treatment with the lowest level of concentrate. For Anglo-nubian the amount of concentrate influenced (P<0.05) milk production. Milk production increased (P<0.05) with bST application from 1.73 kg/animal/day to 2.04 kg/animal/day. It was concluded that milk production in the studyed breeds can be improved with BST application

Ac transport studies in polymers by a resistor network and transfer matrix approaches: application to polyaniline

A statistical model of resistor network is proposed to describe a polymer structure and to simulate the real and imaginary components of its ac resistivity. It takes into account the polydispersiveness of the material as well as intrachain and interchain charge transport processes. By the application of a transfer matrix technique, it reproduces ac resistivity measurements carried out with polyaniline films in different doping degrees and at different temperatures. Our results indicate that interchain processes govern the resistivity behavior in the low frequency region while, for higher frequencies, intrachain mechanisms are dominant.Comment: LaTeX file, 15 pages, 5 ps figures, to appear in Phys. Rev.

Energy Technology Roll-Out for Climate Change Mitigation: A Multi-Model Study for Latin America

AbstractIn this paper we investigate opportunities for energy technology deployment under climate change mitigation efforts in Latin America. Through several carbon tax and CO2 abatement scenarios until 2050 we analyze what resources and technologies, notably for electricity generation, could be cost-optimal in the energy sector to significantly reduce CO2 emissions in the region. By way of sensitivity test we perform a cross-model comparison study and inspect whether robust conclusions can be drawn across results from different models as well as different types of models (general versus partial equilibrium). Given the abundance of biomass resources in Latin America, they play a large role in energy supply in all scenarios we inspect. This is especially true for stringent climate policy scenarios, for instance because the use of biomass in power plants in combination with CCS can yield negative CO2 emissions. We find that hydropower, which today contributes about 800 TWh to overall power production in Latin America, could be significantly expanded to meet the climate policies we investigate, typically by about 50%, but potentially by as much as 75%. According to all models, electricity generation increases exponentially with a two- to three-fold expansion between 2010 and 2050. We find that in our climate policy scenarios renewable energy overall expands typically at double-digit growth rates annually, but there is substantial spread in model results for specific options such as wind and solar power: the climate policies that we simulate raise wind power in 2050 on average to half the production level that hydropower provides today, while they raise solar power to either a substantially higher or a much lower level than hydropower supplies at present, depending on which model is used. Also for CCS we observe large diversity in model outcomes, which reflects the uncertainties with regard to its future implementation potential as a result of the challenges this CO2 abatement technology experiences. The extent to which different mitigation options can be used in practice varies greatly between countries within Latin America, depending on factors such as resource potentials, economic performance, environmental impacts, and availability of technical expertise. We provide concise assessments of possible deployment opportunities for some low-carbon energy options, for the region at large and with occasional country-level detail in specific cases

Macroalgal meadow habitats support fish and fisheries in diverse tropical seascapes

Ecosystems are linked by the movement of organisms across habitat boundaries and the arrangement of habitat patches can affect species abundance and composition. In tropical seascapes many coral reef fishes settle in adjacent habitats and undergo onto-genetic habitat shifts to coral reefs as they grow. Few studies have attempted to measure at what distances from nursery habitats these fish migrations (connectivity) cease to exist and how the abundance, biomass and proportion of nursery species change on coral reefs along distance gradients away from nursery areas. The present study examines seascape spatial arrangement, including distances between habitats, and its con-sequences on connectivity within a tropical seascape in Mozambique using a seascape ecology approach. Fish and habitat surveys were undertaken in 2016/2017 and a thematic habitat map was created in ArcGIS, where cover and distances between habitat patches were calculated. Distance to mangroves and seagrasses were significant predictors for abundance and biomass of most nursery species. The proportions of nursery species were highest in the south of the archipelago, where mangroves were present and decreased with distance to nurseries (mangroves and seagrasses). Some nursery species were absent on reef sites farthest from nursery habitats, at 80 km from mangroves and at 12 km from seagrass habitats. The proportion of nursery/non-nursery snapper and parrotfish species, as well as abundance and biomass of seagrass nursery species abruptly declined at 8 km from seagrass habitats, indicating a threshold distance at which migrations may cease. Additionally, reefs isolated by large stretches of sand and deep water had very low abundances of several nursery species despite being within moderate distances from nursery habitats. This highlights the importance of considering the matrix (sand and deep water) as barriers for fish migration

Thresholds in seascape connectivity: the spatial arrangement of nursery habitats structure fish communities on nearby reefs

Ecosystems are linked by the movement of organisms across habitat boundaries and the arrangement of habitat patches can affect species abundance and composition. In tropical seascapes many coral reef fishes settle in adjacent habitats and undergo ontogenetic habitat shifts to coral reefs as they grow. Few studies have attempted to measure at what distances from nursery habitats these fish migrations (connectivity) cease to exist and how the abundance, biomass and proportion of nursery species change on coral reefs along distance gradients away from nursery areas. The present study examines seascape spatial arrangement, including distances between habitats, and its consequences on connectivity within a tropical seascape in Mozambique using a seascape ecology approach. Fish and habitat surveys were undertaken in 2016/2017 and a thematic habitat map was created in ArcGIS, where cover and distances between habitat patches were calculated. Distance to mangroves and seagrasses were significant predictors for abundance and biomass of most nursery species. The proportions of nursery species were highest in the south of the archipelago, where mangroves were present and decreased with distance to nurseries (mangroves and seagrasses). Some nursery species were absent on reef sites farthest from nursery habitats, at 80 km from mangroves and at 12 km from seagrass habitats. The proportion of nursery/non-nursery snapper and parrotfish species, as well as abundance and biomass of seagrass nursery species abruptly declined at 8 km from seagrass habitats, indicating a threshold distance at which migrations may cease. Additionally, reefs isolated by large stretches of sand and deep water had very low abundances of several nursery species despite being within moderate distances from nursery habitats. This highlights the importance of considering the matrix (sand and deep water) as barriers for fish migration