The role of Dark Matter interaction in galaxy clusters

We consider a toy model to analyze the consequences of dark matter interaction with a dark energy background on the overall rotation of galaxy clusters and the misalignment between their dark matter and baryon distributions when compared to {\Lambda}CDM predictions. The interaction parameters are found via a genetic algorithm search. The results obtained suggest that interaction is a basic phenomenon whose effects are detectable even in simple models of galactic dynamics.Comment: RevTeX 4.1, 5 pages, 3 figure

The Regional Concentration of Industries and the Performance of Firms: A Multilevel Approach

This paper presents the results of a study whose objective was to understand how location within industrial concentrations, like clusters or industrial districts, affects the financial performance of firms. In its theoretical framework, this paper attempts to introduce the reasons behind the alleged superior performance of firms located in these concentrations, the base of the hypothesis formulated in this study. Analysis from a three-level hierarchical linear model applied to a sample of 509 companies located in the state of São Paulo found no evidence that industrial concentrations provide firms with superior performance, contradicting expectations generated by the theory. The decomposition of the variance of performance indicated that the location of the firms and the form with which a city interacts with an industry exerts significant influence on how they will perform. In short, location matters to the future of firms. This finding underlines the need to understand how characteristics of cities or regions can promote or retard the performance of firms

Evaluation of mineral content in maize under flooding.

This study examined the effects of plant mineral content on different cycles of recurrent selection of the flood-tolerant, open-pollinated maize variety BRS 4154 - "Saracura", under soil flooding. Experiments with the main treatments flooded or unflooded were conducted in Sete Lagoas, MG - Brazil. Samples of the cycles 1, 5, 9 and 15 were sown in a randomized block design. The open-pollinated variety BR 107 and single-cross hybrid BRS 1010 were used as flood-susceptible controls. The stress caused by water excess in the soil reduced the nitrogen content in the cycles 5 and 9, and calcium in cycle 15; but increased potassium in cycle 1. However, it did not significantly influence the content of phosphorus, magnesium, sulfur, zinc, and copper. Additionally, recurrent selection under flooding diminished potassium and calcium content along the cycles

Genetic variability and morphological modifications in flooding tolerance in maize, variety BRS-4154.

Maize plants of the variety BRS 4154 - Saracura were evaluated in different cycles of recurrenl selection to determine genetic gains in flooding talerance, arranged in a random block design. The maize variety BRS 4154 in four selection cycles (1, 5. 9 and 15), together with the flooding-sensilive variety BR 107 and siingle cross BRS 1010 as control, were sown and evaluated. The stress caused by waterlogged soi! reduced the weight of 100 seeds and grain yield but did nol affect the number of kernel rows, ear length or prolificacy. Selection for yield resulted in higher yields

Estresse oxidativo em grãos de feijão carioca recém-colhidos.

Esse estudo objetivou avaliar o nível de estresse oxidativo em grãos de feijão carioca, recém-colhidos, por meio da determinação da atividade da superóxido dismutase, teor de peróxido de hidrogênio (H2O2) e nível de peroxidação de lipídeos (dano de membrana).CONAF

Transporte do amônio em colunas com agregados de um Latossolo vermelho distrófico.

Para descrever o transporte do íon amônio em diferentes classes de agregados de um Latossolo Vermelho distrófico realizou-se um experimento de laboratório cujos tratamentos corresponderam a um fatorial 3 x 5, sendo: três fontes de NH4 + [(NH4)2SO4, NH4Cl e NH4NO3] e cinco classes de agregados (2,0-1,0; 1,0-0,5; 0,5-0,25; 0,25-0,105; e <0,105 mm). A unidade experimental foi constituída de uma coluna de vidro saturada, sob vácuo, com uma solução de CaCl2 0,005 mol L-1. Aplicou-se, a seguir, a solução saturante até percolação constante, seguida de um pulso de sete volumes de poros da respectiva fonte a 0,01 mol L-1 de NH4 + (Co) para cada classe de agregados. Foram coletadas frações correspondentes a 0,3 volume de poros do efluente (p) determinando-se as concentrações de NH4 + (C). Calculou-se a relação C/Co para cada fração p, traçando-se curvas experimentais de eluição. Os maiores valores dos fatores de retardamento ocorreram nos agregados de menor tamanho, indicando maior retenção do amônio; na maioria dos tratamentos ocorreu superposição das curvas obtidas por meio dos modelos teóricos, o que indicou que o transporte do amônio no solo se deu, predominantemente, por dispersão. Os ânions acompanhantes apresentaram efeitos semelhantes sobre a lixiviação do NH4 +, nas diferentes classes de agregados

Evapotranspiração de referência obtida pelo Tanque Classe A e por Penmam Monteith (FAO): influência na determinação do Kc da goiabeira em Petrolina, PE.

Esse trabalho teve por objetivo comparar a estimativa da evapotranspiração de referência (ETo), obtida pelos métodos de PenmamMonteith (PM-FAO) e do tanque classe A, na região de Petrolina - PE. As estimativas de ETo foram utilizadas para a determinação do coeficiente de cultura (Kc) da goiabeira cv. Paluma, irrigada por micropaspersão, durante o terceiro ciclo de produção, entre junho e dezembro de 2001. Os valores de ETo estimados pelo tanque classe A foram superiores aos estimados pelo método PM-FAO, com médias de 5,22 e 4,68 mm.dia1, respectivamente. Conseqüentemente, os valores de Kc foram maiores para a ETo estimada pelo método de PM FAO

Nicotinic acid induces antinociceptive and anti-inflammatory effects in different experimental models

AbstractAlthough in vitro studies have shown that nicotinic acid inhibits some aspects of the inflammatory response, a reduced number of in vivo studies have investigated this activity. To the best of our knowledge, the effects induced by nicotinic acid in models of nociceptive and inflammatory pain are not known. Per os (p.o.) administration of nicotinic acid (250, 500 or 1000mg/kg, −1h) inhibited the first and the second phases of the nociceptive response induced by formalin in mice. Nicotinic acid (250 or 500mg/kg, −1 and 3h) also inhibited the mechanical allodynia induced by carrageenan in rats, a model of inflammatory pain. However, in a model of nociceptive pain, exposure of mice to a hot-plate, nicotinic acid was devoid of activity. In addition to inhibiting the nociceptive response in models of inflammatory pain, nicotinic acid (250 or 500mg/kg, p.o., −1 and 3h) inhibited paw edema induced by carrageenan in mice and rats. Picolinic acid (62.5 or 125mg/kg, p.o., −1h), a nicotinic acid isomer, inhibited both phases of the nociceptive response induced by formalin, but not paw edema induced by carrageenan in mice. The other nicotinic acid isomer, isonicotinic acid, was devoid of activity in these two models. In conclusion, our results represent the first demonstration of the activity of nicotinic acid in experimental models of nociceptive and inflammatory pain and also provide further support to its anti-inflammatory activity. It is unlikely that conversion to nicotinamide represents an important mechanism to explain the antinociceptive and anti-inflammatory activities of nicotinic acid. The demonstration of new activities of nicotinic acid, a drug that has already been approved for clinical use and presents a positive safety record, may contribute to raise the interest in conducting clinical trials to investigate its usefulness in the treatment of painful and inflammatory diseases