111 research outputs found

    Medición de la conductividad hidráulica bajo trayectorias horizontales en suelos granulares

    Get PDF
    In geotechnical structures, the permeability-dependent stability analysis is generally evaluated under vertical trajectories, because most permeameters are configured so that the water passes through the porous medium in this way. However, it is clear from the physical point of view that water can flow along different paths, including preferential ways that can include horizontal trajectories, parallel to the deposit of the stratum. The foregoing implies that both the vertical and horizontal component of the hydraulic conductivity or permeability coefficient must be estimated for a given stratum. The current research aims to explore possibilities for measuring the coefficient of permeability in horizontal trajectories, on granular soils, under a constant condition of relative density. For this purpose, a special chamber attached to a constant head permeameter was designed and constructed, which allows to measure the permeability in conditions of horizontal flow parallel to the soil layers. The proposed camera also admits the estimation of the permeability coefficient by combining stratifications of different granular soils, where the trajectories are not perfectly horizontal, but have diagonal paths. The results are compared with data obtained by conventional vertical flow permeameters, in order to check the difference in the measurements considering both situations in the samples. As a conclusion, it is important to report that there is evidently a difference in the permeability coefficients measured under different trajectories,En las estructuras geotécnicas generalmente el análisis de estabilidad dependiente de la permeabilidad, es evaluado bajo trayectorias verticales, debido a que la mayoría de permeámetros están configurados para que el agua atraviese de esta manera el medio poroso. No obstante, es claro desde el punto de vista físico que el agua puede fluir siguiendo diferentes caminos, entre ellos recorridos preferenciales que pueden incluir trayectorias horizontales paralelas a la depositación del estrato. Lo anterior implica que se debe estimar para un estrato, tanto la componente vertical, como horizontal de la conductividad hidráulica o coeficiente de permeabilidad. En la investigación actual se pretende explorar posibilidades de medición del coeficiente de permeabilidad en trayectorias horizontales, en suelos granulares, bajo una condición constante de densidad relativa. Para ello se diseñó y construyó una cámara especial adosada a un permeámetro de cabeza constante, que permite medir la permeabilidad en condiciones de flujo horizontal paralelo a los estratos. La cámara propuesta admite también, la estimación del coeficiente de permeabilidad combinando estratificaciones de diferentes suelos granulares, donde las trayectorias no son perfectamente horizontales, sino presentan recorridos diagonales. Los resultados son comparados con datos obtenidos mediante permeámetros convencionales de flujo vertical, con el fin de comprobar la diferencie en las mediciones considerando ambas situaciones en las muestras. Como conclusión generar es importante reportar que evidentemente existe una diferencia en los coeficientes de permeabilidad medidos bajo diferentes trayectorias

    Teaching Modern Languages on Ancient Roots. Anche le pietre parlano

    Get PDF
    Possono le pietre raccontarci qualcosa? Si possono imparare le lingue osservando i resti archeologici di Verona, Tarragona e Kalamata? Perché le lingue hanno una storia? Perché abbiamo bisogno di rappresentare le parole? In questo volume poniamo anche altri interrogativi e cerchiamo alcune risposte

    Molecular Characterization of the Region 7q22.1 in Splenic Marginal Zone Lymphomas

    Get PDF
    Splenic marginal zone lymphomas (SMZL) are an uncommon type of B-cell non-Hodgkin's lymphoma (NHL-B) in which no specific chromosomal translocations have been described. In contrast, the most frequent cytogenetic abnormality is the loss of the long arm of chromosome 7 (7q). Previous reports have located this loss in the 7q32 region. In order to better characterize the genomic imbalances in SMZL, molecular studies were carried out in 73 patients with SMZL. To gain insight into the mapping at 7q a tiling array was also used. The results confirmed the loss of 7q as the most frequent change. In addition, several abnormalities, including 4q22.1, 1q21.3–q22, 6q25.3, 20q13.33, 3q28, 2q23.3–q24.1 and 17p13, were also present. A loss of 7q22.1 at 99925039–101348479 bp was observed in half of the cases. The region of 7q22.1 has not previously been characterised in SMZL. Our results confirmed the presence of a new region of loss on chromosome 7 in these NHL

    Associations between healthy eating patterns and indicators of metabolic risk in postmenopausal women

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Since human diets contain many components that may work synergistically to prevent or promote disease, assessing diet quality may be informative. The purpose of this study was to investigate the association between quality diet, by using Healthy Eating Index (HEI), and metabolic risk indicators in postmenopausal women.</p> <p>Methods</p> <p>This cross-sectional study included a total of 173 Brazilian women, aged 45-75 years, seeking healthcare at a public outpatient center. Food consumption assessed by 24 h-recall food inquiry was used to calculate HEI scores: >80 implied diet good, 80-51 diet "needed improvement", and <51 diet poor. Anthropometric data included: body mass index (BMI = weight/height<sup>2</sup>), waist-circumference (WC), body fat (%BF) and lean mass (%LM). Data on total cholesterol (TC), high density lipoprotein cholesterol (HDLC), low density lipoprotein cholesterol (LDLC), and triglycerides (TG) were also collected. Fisher's Exact test, and logistic regression method (to determine odds ratio, OR) were used in the statistical analysis.</p> <p>Results</p> <p>Overweight and obesity were observed in 75.7% of the participants. Excessive %BF (> 35%) was observed in 56.1%, while %LM was reduced (< 70%) in 78.1%. WC was elevated (≥88 cm) in 72.3%. Based on HEI values, diet quality was good in 3% (5/173), needed improvement in 48.5% (84/173), and was poor in 48.5% (84/173) of the cases. In this group, 75% of women had high intakes of lipids (> 35%), predominantly saturated and monounsaturated fat. On average, plasma TC, LDLC, and TG levels were higher than recommended in 57.2%, 79.2% and 45.1% of the women, respectively, while HDLC was low in 50.8%. There was association between HEI scores and the %BF that it was higher among women with HEI score < 80 (p = 0.021). There were not observed significant risk associations between HEI and lipid profile.</p> <p>Conclusion</p> <p>Among the Brazilian postmenopausal women attending a public outpatient clinic, diet was considered to need improvement or to be of poor quality, attributed to high saturated fat ingestion, which probably caused a negative impact on metabolic risk indicators, namely body composition.</p

    A Draft of the Human Septin Interactome

    Get PDF
    Background: Septins belong to the GTPase superclass of proteins and have been functionally implicated in cytokinesis and the maintenance of cellular morphology. They are found in all eukaryotes, except in plants. In mammals, 14 septins have been described that can be divided into four groups. It has been shown that mammalian septins can engage in homo- and heterooligomeric assemblies, in the form of filaments, which have as a basic unit a hetero-trimeric core. In addition, it has been speculated that the septin filaments may serve as scaffolds for the recruitment of additional proteins. Methodology/Principal Findings: Here, we performed yeast two-hybrid screens with human septins 1-10, which include representatives of all four septin groups. Among the interactors detected, we found predominantly other septins, confirming the tendency of septins to engage in the formation of homo- and heteropolymeric filaments. Conclusions/Significance: If we take as reference the reported arrangement of the septins 2, 6 and 7 within the heterofilament, (7-6-2-2-6-7), we note that the majority of the observed interactions respect the ""group rule"", i.e. members of the same group (e. g. 6, 8, 10 and 11) can replace each other in the specific position along the heterofilament. Septins of the SEPT6 group preferentially interacted with septins of the SEPT2 group (p<0.001), SEPT3 group (p<0.001) and SEPT7 group (p<0.001). SEPT2 type septins preferentially interacted with septins of the SEPT6 group (p<0.001) aside from being the only septin group which interacted with members of its own group. Finally, septins of the SEPT3 group interacted preferentially with septins of the SEPT7 group (p<0.001). Furthermore, we found non-septin interactors which can be functionally attributed to a variety of different cellular activities, including: ubiquitin/sumoylation cycles, microtubular transport and motor activities, cell division and the cell cycle, cell motility, protein phosphorylation/signaling, endocytosis, and apoptosis.Fundao de Amparo a Pesquisa do Estado Sao Paulo (Fapesp)CAPES: Coordenao de Aperfeioamento de Pessoal de Navel SuperiorConselho Nacional de Pesquisa e Desenvolvimento (CNPq)Laboratorio Nacional de Biociencias-Centro Nacional de Pesquisa em Energia e Materais (LNBio-CNPEM

    Comparative Genomic Analysis of Human Fungal Pathogens Causing Paracoccidioidomycosis

    Get PDF
    Paracoccidioides is a fungal pathogen and the cause of paracoccidioidomycosis, a health-threatening human systemic mycosis endemic to Latin America. Infection by Paracoccidioides, a dimorphic fungus in the order Onygenales, is coupled with a thermally regulated transition from a soil-dwelling filamentous form to a yeast-like pathogenic form. To better understand the genetic basis of growth and pathogenicity in Paracoccidioides, we sequenced the genomes of two strains of Paracoccidioides brasiliensis (Pb03 and Pb18) and one strain of Paracoccidioides lutzii (Pb01). These genomes range in size from 29.1 Mb to 32.9 Mb and encode 7,610 to 8,130 genes. To enable genetic studies, we mapped 94% of the P. brasiliensis Pb18 assembly onto five chromosomes. We characterized gene family content across Onygenales and related fungi, and within Paracoccidioides we found expansions of the fungal-specific kinase family FunK1. Additionally, the Onygenales have lost many genes involved in carbohydrate metabolism and fewer genes involved in protein metabolism, resulting in a higher ratio of proteases to carbohydrate active enzymes in the Onygenales than their relatives. To determine if gene content correlated with growth on different substrates, we screened the non-pathogenic onygenale Uncinocarpus reesii, which has orthologs for 91% of Paracoccidioides metabolic genes, for growth on 190 carbon sources. U. reesii showed growth on a limited range of carbohydrates, primarily basic plant sugars and cell wall components; this suggests that Onygenales, including dimorphic fungi, can degrade cellulosic plant material in the soil. In addition, U. reesii grew on gelatin and a wide range of dipeptides and amino acids, indicating a preference for proteinaceous growth substrates over carbohydrates, which may enable these fungi to also degrade animal biomass. These capabilities for degrading plant and animal substrates suggest a duality in lifestyle that could enable pathogenic species of Onygenales to transfer from soil to animal hosts.National Institute of Allergy and Infectious Diseases (U.S.)National Institutes of Health. Department of Health and Human Services (contract HHSN266200400001C)National Institutes of Health. Department of Health and Human Services(contract HHSN2722009000018C)Brazil. National Council for Scientific and Technological Developmen

    Long-term thermal sensitivity of Earth’s tropical forests

    Get PDF
    The sensitivity of tropical forest carbon to climate is a key uncertainty in predicting global climate change. Although short-term drying and warming are known to affect forests, it is unknown if such effects translate into long-term responses. Here, we analyze 590 permanent plots measured across the tropics to derive the equilibrium climate controls on forest carbon. Maximum temperature is the most important predictor of aboveground biomass (−9.1 megagrams of carbon per hectare per degree Celsius), primarily by reducing woody productivity, and has a greater impact per °C in the hottest forests (>32.2°C). Our results nevertheless reveal greater thermal resilience than observations of short-term variation imply. To realize the long-term climate adaptation potential of tropical forests requires both protecting them and stabilizing Earth’s climate

    Crop pests and predators exhibit inconsistent responses to surrounding landscape composition

    Get PDF
    The idea that noncrop habitat enhances pest control and represents a win–win opportunity to conserve biodiversity and bolster yields has emerged as an agroecological paradigm. However, while noncrop habitat in landscapes surrounding farms sometimes benefits pest predators, natural enemy responses remain heterogeneous across studies and effects on pests are inconclusive. The observed heterogeneity in species responses to noncrop habitat may be biological in origin or could result from variation in how habitat and biocontrol are measured. Here, we use a pest-control database encompassing 132 studies and 6,759 sites worldwide to model natural enemy and pest abundances, predation rates, and crop damage as a function of landscape composition. Our results showed that although landscape composition explained significant variation within studies, pest and enemy abundances, predation rates, crop damage, and yields each exhibited different responses across studies, sometimes increasing and sometimes decreasing in landscapes with more noncrop habitat but overall showing no consistent trend. Thus, models that used landscape-composition variables to predict pest-control dynamics demonstrated little potential to explain variation across studies, though prediction did improve when comparing studies with similar crop and landscape features. Overall, our work shows that surrounding noncrop habitat does not consistently improve pest management, meaning habitat conservation may bolster production in some systems and depress yields in others. Future efforts to develop tools that inform farmers when habitat conservation truly represents a win–win would benefit from increased understanding of how landscape effects are modulated by local farm management and the biology of pests and their enemies
    corecore