165 research outputs found

    Liquefaction Fragilities for Buried Lifelines

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    For buried structures, such as conduits and underground pipes, liquefaction induced forces will depend on the volume of soil surrounding the structure that will liquefy. Here, a methodology to calculate the probability of the onset of liquefaction at a given depth in a soil deposit is extended to assess the probability that a specified volume of soil will liquefy when liquefaction occurs at a given depth in the deposit. To account for the variability of soil properties with depth, the soil deposit is divided into horizontal layers and the volume of liquefied soil in each layer is calculated as the product of the layer thickness by the lateral extent of liquefaction. Within each layer, the horizontal variability of the soil properties is described by a homogeneous and axisymmetric random field. It is assumed that the ground motions in the horizontal direction are perfectly correlated. The results are presented in terms of the probability of liquefaction spreading over a given area (a circle of radius R) as a function of the intensity of the ground motion

    Genetic determinants and absence of breast cancer in Xavante Indians in Sangradouro Reserve, Brazil

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    Genetic compositions of distinct human populations are different. How genomic variants influence many common and rare genetic diseases is always of great medical and anthropological interest, and understanding of genetic architectures of population groups in relation to diseases can advance our knowledge of medicine. Here, we have studied the genomic architecture of a group of Xavante Indians, an indigenous population in Brazil, and compared them with normal populations from the 1000 Genomes Projects. Principal component analysis (PCA) indicates that the Xavante Indians are genetically distinctive when compared to other ethnic groups. No incidence of breast cancer cases has ever been reported in the population, and polygenic risk analysis indicates extremely low breast cancer risk in this population when compared with germline TCGA (The Cancer Genome Atlas) breast cancer normal control samples. Low germinal mutation burden among this population is also observed. Our findings will help to deepen the understanding of breast cancer and might also provide new approaches to study the disease.publishersversionpublishe

    Effect of chaethomellic acid on renal function in rat model of chronic renal failure

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    To study the effect of chronic treatment with chaethomellic acid (CA), a highly specific inhibitor of ras farnesyl-protein transferase, on the renal function of rats with renal failure induced by renal mass reduction. Male Wistar rats were subjected to 5/6 nephrectomy (RMR) or sham-operated (SO). One week after surgery, rats have been placed in four experimental groups: RMR: rats without treat- ment (n=13); RMR+CA: rats treated with CA (n=13); SO: rats without treatment (n=13); SO+AC: rats treated with CA (n=13). CA was intraperitoneally administered in a dose of 0.23 g/Kg three times a week for 6 months. Creatinine, blood urea nitrogen (BUN) and protein were measured in serum and/or urine by routine laboratory techniques. BUN, creatinine, and proteinuria were significantly lower and creatinine clearance was significantly higher in SO and SO+AC groups when compared with RMR and RMR+AC groups. There were no differ- ences in creatinine, proteinuria and creatinine clearance between RMR and RMR+AC groups. Anyway, RMR+AC group showed significant lower BUN and lower creatinine and proteinuria, and higher creatinine clearance than RMR group. In a model of renal failure induced by RMR, 6 months of treatment with CA may have some beneficial effect on renal function

    Effect of chaethomellic acid on renal function in a rat model of chronic renal failure

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    To study the effect of chronic treatment with chaethomellic acid (CA), a highly specific inhibitor of ras farnesyl-protein transferase, on the renal function of rats with renal failure induced by renal mass reduction. Male Wistar rats were subjected to 5/6 nephrectomy (RMR) or sham-operated (SO). One week after surgery, rats have been placed in four experimental groups: RMR: rats without treat- ment (n=13); RMR+CA: rats treated with CA (n=13); SO: rats without treatment (n=13); SO+AC: rats treated with CA (n=13). CA was intraperitoneally administered in a dose of 0.23 g/Kg three times a week for 6 months. Creatinine, blood urea nitrogen (BUN) and protein were measured in serum and/or urine by routine laboratory techniques. BUN, creatinine, and proteinuria were significantly lower and creatinine clearance was significantly higher in SO and SO+AC groups when compared with RMR and RMR+AC groups. There were no differ- ences in creatinine, proteinuria and creatinine clearance between RMR and RMR+AC groups. Anyway, RMR+AC group showed significant lower BUN and lower creatinine and proteinuria, and higher creatinine clearance than RMR group. In a model of renal failure induced by RMR, 6 months of treatment with CA may have some beneficial effect on renal function

    A System Core Ontology for Capability Emergence Modeling

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    To properly understand organizational adaptation and innovation, it is critical to understand the emergence phenomenon, i.e., how the capabilities of a system emerge after changes. However, for this, we should be able to explain systems, their structure, behavior, and capabilities. In pursuit of an understanding of the emergence phenomenon and the nature of those new kinds of systems in organizations, we propose a well-founded system core ontology based on the Unified Foundational Ontology. The ontology is also grounded in system science definitions and disposition theories. For a more integrated explanation of emergence, the proposed ontology considers distinct perspectives of a system, such as its composition, structure, properties, and functions. In the end, we discuss the applications and implications of the proposed ontology on the enterprise architecture area and emergence modeling

    Participation of 5-HT and AT 1 Receptors within the Rostral Ventrolateral Medulla in the Maintenance of Hypertension in the Goldblatt 1 Kidney-1 Clip Model

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    The hypothesis that changes in neurotransmission within the rostral ventrolateral medulla (RVLM) are important to maintain the high blood pressure (BP) was tested in Goldblatt one kidney-one clip hypertension model (1K-1C). Male Wistar rats were anesthetized (urethane 1.2 g/kg, i.v.), and the effects of bilateral microinjections into the RVLM of the following drugs were measured in 1K-1C or control groups: glutamate (0.1 mol/L, 100 nL) and its antagonist kynurenic acid (0.02 mol/L, 100 nL), the angiotensin AT 1 receptor antagonist candesartan (0.01 mol/L, 100 nL), and the nonselective 5-HT receptor antagonist methiothepin (0.06 mol/L, 100 nL). Experiments in 1K-1C rats were performed 6 weeks after surgery. In anesthetized rats glutamate response was larger in hypertensive than in normotensive rats (H: Δ67 ± 6.5; N: Δ43 ± 3.54 mmHg). In contrast, kynurenic acid microinjection into the RVLM did not cause any change in BP in either group. The blockade of either AT 1 or 5-HT receptors within the RVLM decreased BP only in 1K-1C rats. A largest depressor response was caused by 5-HT receptor blockade. The data suggest that 5-HT and AT 1 receptors act tonically to drive RVLM in 1K-1C rats, and these actions within RVLM contribute to the pathogenesis of this model of hypertension

    Glycerol ethers as hydrotropes and their use to enhance the solubility of phenolic acids in water

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    The use of glycerol ethers (with alkyl side chain ranging from one to six methyl groups) as hydrotropes to enhance the solubility of gallic and syringic acids in water was here studied. These compounds were selected by their intrinsic interest and for serving as models for lignin fractions. The results obtained were compared against traditional co-solvents, demonstrating the exceptional hydrotropic ability of glycerol ethers. Setschenow constants show that the hydrophobicities of both solute and hydrotrope play an important role in the solubility enhancement by hydrotropy, shedding light into its molecular mechanism

    Undergraduate Biology Education Research Gordon Research Conference: A Meeting Report

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    The 2019 Undergraduate Biology Education Research Gordon Research Conference (UBER GRC), titled “Achieving Widespread Improvement in Undergraduate Education,” brought together a diverse group of researchers and practitioners working to identify, promote, and understand widespread adoption of evidence-based teaching, learning, and success strategies in undergraduate biology. Graduate students and postdocs had the additional opportunity to present and discuss research during a Gordon Research Seminar (GRS) that preceded the GRC. This report provides a broad overview of the UBER GRC and GRS and highlights major themes that cut across invited talks, poster presentations, and informal discussions. Such themes include the importance of working in teams at multiple levels to achieve instructional improvement, the potential to use big data and analytics to inform instructional change, the need to customize change initiatives, and the importance of psychosocial supports in improving undergraduate student well-being and academic success. The report also discusses the future of the UBER GRC as an established meeting and describes aspects of the conference that make it unique, both in terms of facilitating dissemination of research and providing a welcoming environment for conferees
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