Noncommutative Field Theory: Nonrelativistic Fermionic Field Coupled to the Chern-Simons Field in 2+1 Dimensions

We study a noncommutative nonrelativistic fermionic field theory in 2+1 dimensions coupled to the Chern-Simons field. We perform a perturbative analysis of model and show that up to one loop the ultraviolet divergences are canceled and the infrared divergences are eliminated by the noncommutative Pauli term.Comment: Some references adde

Growth, yield, water and effluent quality in ponds with different management during tambaqui juvenile production.

Crescimento, produção e qualidade da água e do efluente em viveiro de tambaqui com diferentes manejos durante a recria

The Noncommutative Supersymmetric Nonlinear Sigma Model

We show that the noncommutativity of space-time destroys the renormalizability of the 1/N expansion of the O(N) Gross-Neveu model. A similar statement holds for the noncommutative nonlinear sigma model. However, we show that, up to the subleading order in 1/N expansion, the noncommutative supersymmetric O(N) nonlinear sigma model becomes renormalizable in D=3. We also show that dynamical mass generation is restored and there is no catastrophic UV/IR mixing. Unlike the commutative case, we find that the Lagrange multiplier fields, which enforce the supersymmetric constraints, are also renormalized. For D=2 the divergence of the four point function of the basic scalar field, which in D=3 is absent, cannot be eliminated by means of a counterterm having the structure of a Moyal product.Comment: 15 pages, 7 figures, revtex, minor modifications in the text, references adde

Preferência alimentar de filhotes e jovens de Kinosternon scorpioides em cativeiro.

O muçuã (Kinosternon scorpioides), quelônio semi-aquático de água doce encontrado na Amazônia brasileira, possui hábito alimentar onívoro. Visto a carência de pesquisas, este estudo possui o objetivo de avaliar a preferência alimentar entre filhotes e jovens da espécie por dieta de origem animal e vegetal. O experimento foi conduzido no Projeto Bio-Fauna/ISARH/UFRA, sediado em Belém, Pará. Foram utilizados 28 animais da espécie K. scorpioides divididos em 2 grupos: jovens e filhotes, e a estes foram oferecidos alimentos de origem animal (carne bovina, frango e peixe) e origem vegetal: hortaliças (jerimum, cenoura, beterraba e batata doce) e frutas (banana, mamão e manga). Observou-se que existe diferença significativa na preferência alimentar por alimentos de origem animal por parte dos filhotes e dos jovens. Neste estudo foi observada uma variação considerável da preferência por alimentos de origem animal e vegetal, considerando a porcentagem dos alimentos consumidos nas diferentes faixas etárias. Observamos que há um aumento significativo no consumo de vegetais em função da idade dos indivíduos, quando comparamos o grupo de filhotes com os jovens. Dentre os itens testados, os de maior aceitação foram os alimentos de origem animal que apresentaram maior consumo independente da faixa etária dos animais. As diferenças dos valores absolutos e percentuais dos diferentes alimentos de origem vegetal pelos grupos foram significativas, demonstrando um aumento no consumo de alimentos de origem vegetal ao longo do desenvolvimento

Climatology of easterly wave disturbances over the tropical South Atlantic

A 21-yr climatology of Easterly Waves Disturbances (EWDs) over the Tropical South Atlantic (TSA) has been examined using data from the European Centers for Medium-Range Weather Forecasting (ECMWF) interim reanalysis (ERAI) and satellite data. This includes the frequency distribution of EWDs and their interannual variability. The large-scale environment associated with EWDs has been investigated for the coastal region of Northeast Brazil (NEB) for the rainy (April-August) season using a composite analysis. To better understand the life cycle of EWDs, an automated tracking scheme has been used to track vorticity centers associated with the EWDs in the ERAI data. EWDs were first identified in ERAI, resulting in 518 observed cases. These were found to show notable interannual variability with around 16-40 episodes by year and with average lifetime of 4-6 days. Of the identified EWDs, 97% reached the coast of NEB, of which 64% were convective in nature and 14% moved across the NEB region and reached the Amazon. The annual occurrence of EWDs seems to be lower (higher) during El Niño (La Niña). The monthly occurrence of EWDs shows higher activity in the rainy season. EWDs originate in association with five types of system: cold fronts, convective clusters from the west coast of Africa, Intertropical Convergence Zone and Tropical Upper Tropospheric Cyclonic Vortices. The composite analysis presents strong relative vorticity (RV) and divergence anomalies at low levels, as well as in the vertical profiles of relative humidity and vertical velocity (omega). The precipitation composites show that the EWDs propagate between the TSA and NEB and contribute at least 60% of the total rainfall over the east coast of NEB throughout the rainy season