Topology and Dynamics in Complex Networks: The Role of Edge Reciprocity

A key issue in complex systems regards the relationship between topology and dynamics. In this work, we use a recently introduced network property known as steering coefficient as a means to approach this issue with respect to different directed complex network systems under varying dynamics. Theoretical and real-world networks are considered, and the influences of reciprocity and average degree on the steering coefficient are quantified. A number of interesting results are reported that can assist the design of complex systems exhibiting larger or smaller relationships between topology and dynamics

Germoplasm bank of umburana-de-cheiro of the Embrapa Semiarido.

SINBIO 2013

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

Chromosome study in Schistocerca (Orthoptera-Acrididae-Cyrtacanthacridinae): karyotypes and distribution patterns of constitutive heterochromatin and nucleolus organizer regions (NORs).

Chromosome analyses were performed in two grasshopper species of the genus Schistocerca, S. pallens and S. flavofasciata. Both species shared the same diploid number (2n = 23, X in males; 2n = 24, XX in females); and a con- served karyotype composed exclusively of acrocentric chromosomes but differed in their distribution patterns of constitutive heterochromatin and nucleolus organizer regions (NORs). Constitutive heterochromatin was located in the pericentromeric region of alI chromosomes in both species. S. flavofasciata presented an additional C-band on the distal region of the long arm of a small autosome pair (S9). Nucleolus organizer regions (NORs), revealed by silver nitrate staining (Ag-NORs), were observed on a medium autosome pair (M5) in both species. S. pallens presented an additional NOR-bearing autosome (M6). The same sites were labeled after FISH with an rDNA probe in S. pallens cells

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