Scaling of variables and the relation between noncommutative parameters in Noncommutative Quantum Mechanics

We consider Noncommutative Quantum Mechanics with phase space noncommutativity. In particular, we show that a scaling of variables leaves the noncommutative algebra invariant, so that only the self-consistent effective parameters of the model are physically relevant. We also discuss the recently proposed relation of direct proportionality between the noncommutative parameters, showing that it has a limited applicability.Comment: Revtex4, 4 pages; version to match the published on

Produção de mudas de Carapa Guianensis Aubl. em diferentes tamanhos de recipientes, para uso em sistemas agroflorestais.

A andiroba é uma das espécies de múltiplo uso mais conhecida da Região Amazônica. Por ser uma espécie de uso múltiplo e rápido crescimento tem grande potencial para utilização em programas de recuperação de áreas degradadas na Amazônia brasileira, na forma de monocultivo ou em sistemas agroflorestais. Contudo, por se tratar de uma espécie pouco domesticada, informações básicas relativas ao seu cultivo ainda são escassas. Nesse sentido, o objetivo desse trabalho foi avaliar o efeito de diferentes tamanhos de recipientes no crescimento de mudas de andiroba. O experimento foi conduzido no viveiro da área experimental da Embrapa Acre, no município de Rio Branco, AC. Foram testados três tratamentos, compostos por três tamanhos de sacos de mudas: pequeno (10 cm x 20 cm), médio (17 cm x 30 cm) e grande (27 cm x 36 cm). O delineamento experimental utilizado foi inteiramente casualizado, com 10 repetições, constituídas de 8 plantas por parcela. Houve diferença significativa para todas as variáveis analisadas, verificando-se um efeito positivo do tamanho do recipiente no crescimento de mudas de andiroba. O recipiente de maior tamanho (27 cm x 36 cm) proporcionou melhor crescimento das mudas

Probing protein sequences as sources for encrypted antimicrobial peptides

Starting from the premise that a wealth of potentially biologically active peptides may lurk within proteins, we describe here a methodology to identify putative antimicrobial peptides encrypted in protein sequences. Candidate peptides were identified using a new screening procedure based on physicochemical criteria to reveal matching peptides within protein databases. Fifteen such peptides, along with a range of natural antimicrobial peptides, were examined using DSC and CD to characterize their interaction with phospholipid membranes. Principal component analysis of DSC data shows that the investigated peptides group according to their effects on the main phase transition of phospholipid vesicles, and that these effects correlate both to antimicrobial activity and to the changes in peptide secondary structure. Consequently, we have been able to identify novel antimicrobial peptides from larger proteins not hitherto associated with such activity, mimicking endogenous and/or exogenous microorganism enzymatic processing of parent proteins to smaller bioactive molecules. A biotechnological application for this methodology is explored. Soybean (Glycine max) plants, transformed to include a putative antimicrobial protein fragment encoded in its own genome were tested for tolerance against Phakopsora pachyrhizi, the causative agent of the Asian soybean rust. This procedure may represent an inventive alternative to the transgenic technology, since the genetic material to be used belongs to the host organism and not to exogenous sources

Correlation but no causation between leaf nitrogen and maximum assimilation: the role of drought and reproduction in gas exchange in an understory tropical plant Miconia ciliata (Melastomataceae).

Alternative hypotheses were tested to explain a previously reported anomaly in the response of leaf photosynthetic capacity at light saturation (A..) in Miconia ciliata to dry-season irrigation. The anomaly is characterized by an abrupt increase in leaf A._ for nonirrigated plants at the onset of the rainy season to values that significantly exceeded corresponding measurements for plants that were irrigated during the previous dry season. Hypothesis I posits that a pulse in leaf nitrogen increases CO2 assimilation in nonirrigated plants at the onset of the wet season and is dampened for irrigated plants; this hypothesis was rejected because, although a wet-season nitrogen pulse did occur, it was identical for both irrigated and nonirrigated plants and was preceded by the increase in assimilation by nonirrigated plants. Hypothesis 2 posits that a reproduction-related, compensatory photosynthetic response occurs in nonirrigated plants following the onset of the wet season and is dampened in irrigated plants; consistent with hypothesis 2, high maximum assimilation rates for control plants in the wet season were significantly correlated with fruiting and flowering, whereas irrigation caused flowering and fruiting in the dry season, spreading M. ciliata reproductive activity in irrigated plants across the entire year

The Exact Critical Bubble Free Energy and the Effectiveness of Effective Potential Approximations

To calculate the temperature at which a first-order cosmological phase transition occurs, one must calculate $F_c(T)$, the free energy of a critical bubble configuration. $F_c(T)$ is often approximated by the classical energy plus an integral over the bubble of the effective potential; one must choose a method for calculating the effective potential when $V''<0$. We test different effective potential approximations at one loop. The agreement is best if one pulls a factor of $\mu^4/T^4$ into the decay rate prefactor [where $\mu^2 = V''(\phi_f)$], and takes the real part of the effective potential in the region $V''<0$. We perform a similar analysis on the 1-dimensional kink.Comment: 11 pages plus 3 figures in jyTeX; CALT-68-188

Resposta fisiológica de ovinos da raça Santa Inês alimentados com diferentes níveis de farelo de manga em substituição ao milho.

O experimento foi delineado para avaliar o efeito da substituição do milho por farelo de manga e medir os efeitos das condições climáticas ao longo do dia sobre os parâmetros fisiológicos: temperatura retal (TR), temperatura Superficial (TS) e freqüência respiratória (FR), em ovinos da raça Santa Inês, criados em confinamento em clima semi-árido. Ovinos machos castrados (n = 16) foram submetidos a quatro dietas com diferentes níveis de substituição do milho por farelo de manga. A TR, TS e FR foram medidas a cada hora durante dois períodos de 24 horas. Adotou-se o delineamento de blocos casualizados, com quatro repetições, em esquema fatorial 4 x 12 (níveis de inclusão de farelo de manga x horários de avaliação dos parâmetros fisiológicos). Não foi observado influência da dieta na TR, TS e FR dos ovinos, entretanto observou-se a influência das condições climáticas

Drought impacts on children's respiratory health in the Brazilian Amazon.

notes: PMCID: PMC3893650types: Journal Article; Research Support, Non-U.S. Gov'tThis is an open access article that is freely available in ORE or from the publisher's web site. Please cite the published version.Drought conditions in Amazonia are associated with increased fire incidence, enhancing aerosol emissions with degradation in air quality. Quantifying the synergic influence of climate and human-driven environmental changes on human health is, therefore, critical for identifying climate change adaptation pathways for this vulnerable region. Here we show a significant increase (1.2%-267%) in hospitalisations for respiratory diseases in children under-five in municipalities highly exposed to drought. Aerosol was the primary driver of hospitalisations in drought affected municipalities during 2005, while human development conditions mitigated the impacts in 2010. Our results demonstrated that drought events deteriorated children's respiratory health particularly during 2005 when the drought was more geographically concentrated. This indicates that if governments act on curbing fire usage and effectively plan public health provision, as a climate change adaptation procedure, health quality would improve and public expenditure for treatment would decrease in the region during future drought events.Natural Environment Research Council (NERC)Economic and Social Research Council (ESRC