Control of dinucleoside polyphosphates by the FHIT-homologous HNT2 gene, adenine biosynthesis and heat shock in Saccharomyces cerevisiae

BACKGROUND: The FHIT gene is lost early in the development of many tumors. Fhit possesses intrinsic ApppA hydrolase activity though ApppA cleavage is not required for tumor suppression. Because a mutant form of Fhit that is functional in tumor suppression and defective in catalysis binds ApppA well, it was hypothesized that Fhit-substrate complexes are the active, signaling form of Fhit. Which substrates are most important for Fhit signaling remain unknown. RESULTS: Here we demonstrate that dinucleoside polyphosphate levels increase 500-fold to hundreds of micromolar in strains devoid of the Saccharomyces cerevisiae homolog of Fhit, Hnt2. Accumulation of dinucleoside polyphosphates is reversed by re-expression of Hnt2 and is active site-dependent. Dinucleoside polyphosphate levels depend on an intact adenine biosynthetic pathway and time in liquid culture, and are induced by heat shock to greater than 0.1 millimolar even in Hnt2+ cells. CONCLUSIONS: The data indicate that Hnt2 hydrolyzes both ApppN and AppppN in vivo and that, in heat-shocked, adenine prototrophic yeast strains, dinucleoside polyphosphates accumulate to levels in which they may saturate Hnt2

Controls of forage selective defoliation by sheep in arid rangelands

Selective grazing by domestic livestock is a major control of plant community structure anddynamics in drylands. However, grazing impact predictions supporting management decisions are fre-quently based on average biomass consumption, neglecting selectivity. We evaluated the relative impor-tance of grazing pressure, total and each species density, and plant dead biomass proportion as drivers ofselective defoliation by sheep in three dominant native grass species in Patagonian steppes. Species werePoa ligularis,Festuca pallescens,andPappostipa speciosa, whicha prioripresent different preference degree bysheep. The relevance of these drivers for differently preferred species has not been simultaneously studied.We recorded the defoliation frequency and degree of the three species (dependent variables) throughout112field surveys. Besides, we recorded grazing management and vegetation structure descriptors (inde-pendent variables).Poa ligulariswas highly defoliated (90% of plants), and grazing pressure was the lead-ing driver (asymptotic exponential relationship). ForF. pallescens, almost 70% of plants were defoliated,and defoliation non-linearly increased as grazing pressure rose and linearly decreased as both its dead bio-mass proportion andP. ligularisdensity increased. ForP. speciosa, defoliation was low (20% of plants) andlinearly decreased as both its dead biomass proportion and the density of the other two species increased.Grazing pressure played a negligible role in this species. These patterns confirmed thatP. ligularis,F. palles-cens,andP. speciosa,respectively, present high, intermediate, and low preference degree by sheep. In con-clusion, ourfindings suggest that (1) selective defoliation can be satisfactorily predicted as function ofgrazing pressure, species densities, and plant dead biomass proportion; (2) grazing pressure becomes amore relevant driver as species preference rises and its effect on defoliation is markedly non-linear; (3) thedead biomass proportion and the abundance of highly preferred species are the leading factors determin-ing less preferred species defoliation; and (4) grazing pressure management by itself is not enough toreduce the high defoliation of preferred species and increase the defoliation of non-preferred species. Thisknowledge is critical for developing effective management practices to control forage species defoliation inrangelands worldwide where species with different preference by herbivores coexist

Spectral Signatures of the Diffusional Anomaly in Water

Analysis of power spectrum profiles for various tagged particle quantities in bulk SPC/E water is used to demonstrate that variations in mobility associated with the diffusional anomaly are mirrored in the exponent of the \onebyf\ region. Monitoring of \onebyf behaviour is shown to be a simple and direct method for linking phenomena on three distinctive length and time scales: the local molecular environment, hydrogen bond network reorganisations and the diffusivity. The results indicate that experimental studies of supercooled water to probe the density dependence of $1/f^\alpha$ spectral features, or equivalent stretched exponential behaviour in time-correlation functions, will be of interest.Comment: 5 Pages, 4 Figure

Caracterização do sistema de controle de pragas adotado pelos produtores de soja do Estado de Roraima.

Não há informações sobre os critérios adotados pelos produtores de soja do Estado de Roraima para o controle das pragas. Por isso, o objetivo deste trabalho foi monitorar o sistema de controle de pragas adotado pelos produtores dessa leguminosa no Estado, ao tempo em que foram caracterizados aspectos sócioeconômicos da atividade produtiva no Estado.bitstream/item/31812/1/doc342010.pd

O(d,d)-invariance in inhomogeneous string cosmologies with perfect fluid

In the first part of the present paper, we show that O(d,d)-invariance usually known in a homogeneous cosmological background written in terms of proper time can be extended to backgrounds depending on one or several coordinates (which may be any space-like or time-like coordinate(s)). In all cases, the presence of a perfect fluid is taken into account and the equivalent duality transformation in Einstein frame is explicitly given. In the second part, we present several concrete applications to some four-dimensional metrics, including inhomogeneous ones, which illustrate the different duality transformations discussed in the first part. Note that most of the dual solutions given here do not seem to be known in the literature.Comment: 25 pages, no figures, Latex. Accepted for publication in General Relativity and Gravitatio

Desempenho de emissores de baixo custo para uso em irrigação localizada.

Os emissores usados na irrigação localizada até pouco tempo eram usados para atender a sistemas de maior custo. Atualmente existem emissores de custo pelo menos 50% menor que os encontrados no mercado. A falta de informações do desempenho desses emissores deixa os produtores sem indicadores para avaliar o produto. O trabalho teve como objetivo avaliar o desempenho de emissores de baixo custo por meio da variação de vazão e de pressão entre o primeiro e ultimo emissor da linha lateral. Usou-se um delineamento experimental inteiramente casualizados em esquema de parcelas subdivididas, com o tipo de emissor na parcela (gotejador autocompensante, gotejador perfurado, de vazão regulável, gotejador difusor de orifício fixo, gotejador ajustável de vazão regulável com regulagem de um giro do emissor e com dois giros do emissor) e pressão de serviço na subparcela (30, 60, 90 e 120 kPa). A pressão de 30 kPa foi a que resultou em maior variação de vazão e pressão e a de 120 kPa a que resultou em menor variação. O emissor perfurado de vazão regulável foi o que apresentou as maiores variações de vazão independente das pressões de serviço e o gotejador autocompensante o que resultou em menores variações de vazão para pressões acima de 30 kPa. As variações de pressão na linha lateral foram menores para o gotejador autocompensante e para o gotejador ajustável de vazão regulável em relação aos demais

O cognitivo popular na organização da produção familiar.

A agricultura familiar, inserida no processo produtivo, recorre a conhecimentos e informações não sistematizadas no âmbito de sua realidade, atuando a partir do cognitivo popular.bitstream/CPAF-AC/3668/1/comunicado89.pd

Bio-based substances from urban waste as auxiliaries for solar photo-Fenton treatment under mild conditions: optimization of operational variables

The use of soluble bio-based organic substances (SBO) obtained from urban wastes to expand the pH region where the photo-Fenton process can be applied has been investigated in this study. For this purpose, a mixture of six pollutants, namely acetaminophen, carbamazepine, amoxicillin, acetamiprid, clofibric acid and caffeine, at an initial concentration of 5 mg L−1 each, has been employed. Surface response methodology, based on the Doehlert matrix, has shown to be a useful tool to determine the effect of pH (in the range 3–7), concentration of SBO (15–25 mg L−1) and iron (2–6 mg L−1) on the performance of the photodegradation of the studied pollutants, measured by their half-life. Results indicate that, at high SBO concentration, the optimum pH shifts in most cases to a higher value (between 3 and 4) and that a significant loss of efficiency of the process was only observed at pH values above 5. An iron concentration of 4–5 mg L−1 and an amount of SBO of 19–22 mg L−1 have been determined to be the optimal conditions for the degradation of most of the studied pollutants at pH = 5.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

Resistência de genótipos de tomateiro a Bemisia tabaci mediada por tricomas glandulares e acilaçúcares.

Foram avaliados genótipos de tomateiro oriundos do cruzamento de Solanum lycopersicum L e Solanum pimpinellifolium L visando encontrar fontes de resistência à mosca-branca.Suplemento. Trabalho apresentado no 52. Congresso Brasileiro de Olericultura, Salvador, 2012

Successful behavior change in obesity interventions in adults: a systematic review of self-regulation mediators

International audienceBackground: Relapse is high in lifestyle obesity interventions involving behavior and weight change. Identifying mediators of successful outcomes in these interventions is critical to improve effectiveness and to guide approaches to obesity treatment, including resource allocation. This article reviews the most consistent self-regulation mediators of medium-and long-term weight control, physical activity, and dietary intake in clinical and community behavior change interventions targeting overweight/obese adults. Methods: A comprehensive search of peer-reviewed articles, published since 2000, was conducted on electronic databases (for example, MEDLINE) and journal reference lists. Experimental studies were eligible if they reported intervention effects on hypothesized mediators (self-regulatory and psychological mechanisms) and the association between these and the outcomes of interest (weight change, physical activity, and dietary intake). Quality and content of selected studies were analyzed and findings summarized. Studies with formal mediation analyses were reported separately. Results: Thirty-five studies were included testing 42 putative mediators. Ten studies used formal mediation analyses. Twenty-eight studies were randomized controlled trials, mainly aiming at weight loss or maintenance (n = 21). Targeted participants were obese (n = 26) or overweight individuals, aged between 25 to 44 years (n = 23), and 13 studies targeted women only. In terms of study quality, 13 trials were rated as " strong " , 15 as " moderate " , and 7 studies as " weak ". In addition, methodological quality of formal mediation analyses was " medium ". Identified mediators for medium-/long-term weight control were higher levels of autonomous motivation, self-efficacy/barriers, self-regulation skills (such as self-monitoring), flexible eating restraint, and positive body image. For physical activity, significant putative mediators were high autonomous motivation, self-efficacy, and use of self-regulation skills. For dietary intake, the evidence was much less clear, and no consistent mediators were identified. Conclusions: This is the first systematic review of mediational psychological mechanisms of successful outcomes in obesity-related lifestyle change interventions. Despite limited evidence, higher autonomous motivation, self-efficacy, and self-regulation skills emerged as the best predictors of beneficial weight and physical activity outcomes; for weight control, positive body image and flexible eating restraint may additionally improve outcomes. These variables represent possible targets for future lifestyle interventions in overweight/obese populations