Microscopic theory of network glasses

A molecular theory of the glass transition of network forming liquids is developed using a combination of self-consistent phonon and liquid state approaches. Both the dynamical transition and the entropy crisis characteristic of random first order transitions are mapped out as a function of the degree of bonding and the density. Using a scaling relation for a soft-core model to crudely translate the densities into temperatures, the theory predicts that the ratio of the dynamical transition temperature to the laboratory transition temperature rises as the degree of bonding increases, while the Kauzmann temperature falls relative to the laboratory transition. These results indicate why highly coordinated liquids should be "strong" while van der Waals liquids without coordination are "fragile".Comment: slightly revised version that has been accepted for publication in Phys. Rev. Let

Rede regional de agroecologia - um plano piloto: um sistema de informações integradas na gestão rural sustentáveis.

Considerando que na atualidade, o maior insumo para produção orgânica no mundo ainda continua sendo a informação. Por outro lado se a informação é importante, a falta dela é um dos grandes entraves. Segundo ALTIERI (2002), um dos grandes obstáculos à agricultura orgânica é a falta de comunicação por parte os produtores, bem como o desconhecimento por parte dos consumidores sobre os benefícios sócio-ambientais da produção orgânica

Proyecto

Uno de los periodos de la vida considerado con cambios intensos y marcado por los profesionales y no profesionales, como difícil de tratar o entender, es la adolescencia. En ella se dan cambios no solo físicos, sino también psíquicos y sociales, por tal razón es necesario que conozcamos y comprendamos todos estos cambios que se van dando, en ese salto de la niñez, pubertad y a la adolescencia. Ante el adolescente se presentan un conjunto de retos personales y metas que desean alcanzar, ya viéndose como adultos, sin embargo hay que reconocer que su inmadurez, puede llevarlos a tomar decisiones personales arriesgadas. Para conducir al adolescente a cumplir sus metas, sin tomar caminos equivocados o desviados es evidente el importante papel que tiene que jugar la familia como punto de apoyo. Los padres deben mantener una comunicación asertiva con sus hijos, evitando así que los amigos se conviertan en su principal referencia a seguir. Hay que mostrarles confianzas para que ellos también confíen en sus padres y acudan fácilmente cuando necesiten de un consejo.Uno de los periodos de la vida considerado con cambios intensos y marcado por los profesionales y no profesionales, como difícil de tratar o entender, es la adolescencia. En ella se dan cambios no solo físicos, sino también psíquicos y sociales, por tal razón es necesario que conozcamos y comprendamos todos estos cambios que se van dando, en ese salto de la niñez, pubertad y a la adolescencia. Ante el adolescente se presentan un conjunto de retos personales y metas que desean alcanzar, ya viéndose como adultos, sin embargo hay que reconocer que su inmadurez, puede llevarlos a tomar decisiones personales arriesgadas. Para conducir al adolescente a cumplir sus metas, sin tomar caminos equivocados o desviados es evidente el importante papel que tiene que jugar la familia como punto de apoyo. Los padres deben mantener una comunicación asertiva con sus hijos, evitando así que los amigos se conviertan en su principal referencia a seguir. Hay que mostrarles confianzas para que ellos también confíen en sus padres y acudan fácilmente cuando necesiten de un consejo

Chaperone activity and structure of monomeric polypeptide binding domains of GroEL

The chaperonin GroEL is a large complex composed of 14 identical 57-kDa subunits that requires ATP and GroES for some of its activities. We find that a monomeric polypeptide corresponding to residues 191 to 345 has the activity of the tetradecamer both in facilitating the refolding of rhodanese and cyclophilin A in the absence of ATP and in catalyzing the unfolding of native barnase. Its crystal structure, solved at 2.5 A resolution, shows a well-ordered domain with the same fold as in intact GroEL. We have thus isolated the active site of the complex allosteric molecular chaperone, which functions as a "minichaperone." This has mechanistic implications: the presence of a central cavity in the GroEL complex is not essential for those representative activities in vitro, and neither are the allosteric properties. The function of the allosteric behavior on the binding of GroES and ATP must be to regulate the affinity of the protein for its various substrates in vivo, where the cavity may also be required for special functions

Estabelecimento de espécies frutíferas e nativas em um sistema agroflorestal biodiverso.

Resumo: Um sistema agroflorestal (SAF) biodiverso foi desenhado a partir de princípios agroecológicos e da experiência de técnicos, pesquisadores e agricultores, visando à recuperação ecológica e econômica de uma área degradada em Jaguariúna (SP). Em novembro de 2009, agricultores de assentamentos da região de Ribeirão Preto (SP) e Itapeva (SP), participaram de um Dia de Campo, que incluiu uma capacitação em SAF, a troca de saberes e a implantação, em mutirão, de parte do sistema. Através do monitoramento de parâmetros ambientais e econômicos, pretende-se, ao longo do tempo, avaliar a eficiência ecológica e produtiva do sistema e definir indicadores de sustentabilidade que possam ser aplicados pelos agricultores. Este trabalho apresenta uma avaliação preliminar do estabelecimento de espécies frutíferas e nativas três anos após a implantação do SAF. Pretende-se assim contribuir para um melhor entendimento de sistemas biodiversos e de seu potencial para uma produção sustentável. Abstract: A biodiverse agroforestry system (SAF) was designed using agroecological principles and the expertise of technicians, reseachers and farmers to achieve ecological and economic recovery of a degraded area in Jaguariúna (SP). In November 2009, farmers in settlements in the region of Ribeirão Preto (SP) and Itapeva (SP), participated in a Field Day, which included a SAF training, knowledge exchange and implementation of a part of the system through a task force. By monitoring environmental and economic parameters, it is intended, over time, to evaluate the ecological and productive efficiency of the system and define sustainability indicators that can be applied by farmers. This paper presents a preliminary assessment of the establishment of native species and fruit three years after the implementation of the SAF. Thus the aim is contributing to a better understanding of biodiverse systems and its potential for sustainable production

Registration of Great Northern Common Bean Cultivar ‘Coyne’ with Enhanced Disease Resistance to Common Bacterial Blight and Bean Rust

Great northern common bean (Phaseolus vulgaris L.) ‘Coyne’ (Reg. No. CV-287, PI 655574) was developed by the dry bean breeding program at the University of Nebraska Agricultural Research Division and released in 2008. It was bred specifically for adaptation to Nebraska growing conditions and for enhanced resistance to common bacterial blight (CBB), a major disease of common bean caused by the seed-borne bacterium Xanthomonas campestris pv. phaseoli (Smith) Dye, and bean common rust Uromyces appendiculatus (Pers.:Pers) Unger. Coyne is a great northern F7:8 line derived from a three-way cross (G95023/Weihing//BelMiNeb-RMR-11). The first cross was made in winter 2003. The F7:8 was tested in advanced yield trials at Scottsbluff and Mitchell, NE, and in growers’ fields in Nebraska. Yield of Coyne was only 47 kg ha–1 lower than ‘Marquis’ in Morrill and Scotts Bluff, NE, counties. Reaction of Coyne to CBB under field conditions was consistent across 3 yr at the West Central Research and Extension Center, North Platte, NE, where fi eld disease ratings of 3.2, 3.5, and 4.4 were recorded in 2005, 2006, and 2007, respectively. Coyne has the Ur-3 and Ur-6 genes for resistance to common bean rust and carries the single dominant hypersensitive I gene that provides resistance to all non-necrotic strains of Bean common mosaic virus. Coyne has bright white seed, blooms 44 d after planting, and is a midseason bean, maturing 91 d after planting

The role of statins in prevention and treatment of community acquired pneumonia: a systematic review and meta-analysis.

BACKGROUND: Emerging epidemiological evidence suggests that statins may reduce the risk of community-acquired pneumonia (CAP) and its complications. PURPOSE: Performed a systematic review to address the role of statins in the prevention or treatment of CAP. DATA SOURCE: Ovid MEDLINE, Cochrane, EMBASE, ISI Web of Science, and Scopus from inception through December 2011 were searched for randomized clinical trials, cohort and case-control studies. STUDY SELECTION: Two authors independently reviewed studies that examined the role of statins in CAP. DATA EXTRACTION: Data about study characteristics, adjusted effect-estimates and quality characteristics was extracted. DATA SYNTHESIS: Eighteen studies corresponding to 21 effect-estimates (eight and 13 of which addressed the preventive and therapeutic roles of statins, respectively) were included. All studies were of good methodological quality. Random-effects meta-analyses of adjusted effect-estimates were used. Statins were associated with a lower risk of CAP, 0.84 (95% CI, 0.74-0.95), I(2) = 90.5% and a lower short-term mortality in patients with CAP, 0.68 (95% CI, 0.59-0.78), I(2) = 75.7%. Meta-regression did not identify sources of heterogeneity. A funnel plot suggested publication bias in the treatment group, which was adjusted by a novel regression method with a resultant effect-estimate of 0.85 (95% CI, 0.77-0.93). Sensitivity analyses using the rule-out approach showed that it is unlikely that the results were due to an unmeasured confounder. CONCLUSIONS: Our meta-analysis reveals a beneficial role of statins for the risk of development and mortality associated with CAP. However, the results constitute very low quality evidence as per the GRADE framework due to observational study design, heterogeneity and publication bias

La inhibición de la síntesis de óxido nítrico durante la colestasis inducida experimentalmente reduce la lesión hepatocelular al facilitar la homeostasis de nitrosotioles

Comunicaciones a congreso

Partial inhibition of RNA polymerase I promotes animal health and longevity

Health and survival in old age can be improved by changes in gene expression. RNA polymerase (Pol) I is the essential, conserved enzyme whose task is to generate the pre-ribosomal RNA (rRNA). We find that reducing the levels of Pol I activity is sufficient to extend lifespan in the fruit fly. This effect can be recapitulated by partial, adult-restricted inhibition, with both enterocytes and stem cells of the adult midgut emerging as important cell types. In stem cells, Pol I appears to act in the same longevity pathway as Pol III, implicating rRNA synthesis in these cells as the key lifespan determinant. Importantly, reduction in Pol I activity delays broad, age-related impairment and pathology, improving the function of diverse organ systems. Hence, our study shows that Pol I activity in the adult drives systemic, age-related decline in animal health and anticipates mortality