Mercado e comercialização na ovinocultura de corte no Brasil.

Resumo: O objetivo deste artigo é apresentar os dados relativos ao mercado e à comercialização da carne ovina no Brasil. Especificamente destacam-se os principais estados produtores, a questão da importação, os preços praticados, a estrutura agrária brasileira como um fator significativo para análise deste setor produtivo e o mercado internacional da ovinocultura. Para tanto são utilizados dados do Instituto Brasileiro de Geografia e Estatística, da Organização das Nações Unidas para Agricultura e Alimentação e outras fontes secundárias especializadas no setor. Os países com o maior rebanho ovino no mundo são China, Índia e Austrália, respectivamente, e a produção de carne ovina está concentrada majoritariamente no continente asiático (52%). Os dados demonstram que o Brasil possui o rebanho ovino concentrado em alguns estados da região Nordeste e no Rio Grande do Sul, os preços aos produtores têm se mantido estáveis no último ano com uma leve tendência de alta, que há uma tendência para o desenvolvimento da indústria de abate e de processamento e, como consequência, uma aproximação ao mercado consumidor. No entanto, conclui-se que persistem entraves organizacionais que impedem o desenvolvimento do setor e que precisam ser superados com urgência. Abstract: The aim of this paper is to present data on the market and the commercialization of sheep meat in Brazil. Specifically we highlight the major producing states, the issue of importation, the prices, the Brazilian agrarian structure as a significant factor for the analysis of this sector and the international market. To achieve this goal, the data were provided by the Brazilian Institute of Geography and Statistics and by the United Nations Food and Agriculture and other specialized secondary sources. Countries with the largest sheep flock in the world are China, India and Australia, respectively, and the meat production is mainly concentrated in Asia (52%). The data show that Brazilian sheep flock are concentrated in a few states in the Northeast and Rio Grande do Sul, the producer prices have remained stable over the last year with a slight upward trend, there is a tendency for the development of slaughter and processing industry and, as a consequence, an approximation to the consumer market. However, it is concluded that organizational obstacles remain and hinder the development of the sector and they must be overcome urgently

Orbital magnetism in axially deformed sodium clusters: From scissors mode to dia-para magnetic anisotropy

Low-energy orbital magnetic dipole excitations, known as scissors mode (SM), are studied in alkali metal clusters. Subsequent dynamic and static effects are explored. The treatment is based on a self-consistent microscopic approach using the jellium approximation for the ionic background and the Kohn-Sham mean field for the electrons. The microscopic origin of SM and its main features (structure of the mode in light and medium clusters, separation into low- and high-energy plasmons, coupling high-energy M1 scissors and E2 quadrupole plasmons, contributions of shape isomers, etc) are discussed. The scissors M1 strength acquires large values with increasing cluster size. The mode is responsible for the van Vleck paramagnetism of spin-saturated clusters. Quantum shell effects induce a fragile interplay between Langevin diamagnetism and van Vleck paramagnetism and lead to a remarkable dia-para anisotropy in magnetic susceptibility of particular light clusters. Finally, several routes for observing the SM experimentally are discussed.Comment: 21 pages, 7 figure

Características morfogênicas e estruturais de Brachiaria ruziziensis submetida a níveis de sombreamento.

o objetivo desse trabalho foi determinar e avaliar as características morfogênicas e estruturais da B. ruziziensis submetida a diferentes níveis de sombreamento

A subgradient method with non-monotone line search

In this paper we present a subgradient method with non-monotone line search for the minimization of convex functions with simple convex constraints. Different from the standard subgradient method with prefixed step sizes, the new method selects the step sizes in an adaptive way. Under mild conditions asymptotic convergence results and iteration-complexity bounds are obtained. Preliminary numerical results illustrate the relative efficiency of the proposed method