242 research outputs found

    Parliamentary roll-call voting as a complex dynamical system:The case of Chile

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    A method is proposed to study the temporal variability of legislative roll-call votes in a parliament from the perspective of complex dynamical systems. We studied the Chilean Chamber of Deputies’ by analyzing the agreement ratio and the voting outcome of each vote over the last 19 years with a Recurrence Quantification Analysis and an entropy analysis (Sample Entropy). Two significant changes in the temporal variability were found: one in 2014, where the voting outcome became more recurrent and with less entropy, and another in 2018, where the agreement ratio became less recurrent and with higher entropy. These changes may be directly related to major changes in the Chilean electoral system and the composition of the Chamber of Deputies, given that these changes occurred just after the first parliamentary elections with non-compulsory voting (2013 elections) and the first elections with a proportional system in conjunction with an increase in the number of deputies (2017 elections) were held.</p

    Chronic Overexpression of Bradykinin in Kidney Causes Polyuria and Cardiac Hypertrophy

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    Acute intra-renal infusion of bradykinin increases diuresis and natriuresis via inhibition of vasopressin activity. However, the consequences of chronically increased bradykinin in the kidneys have not yet been studied. A new transgenic animal model producing an excess of bradykinin by proximal tubular cells (KapBK rats) was generated and submitted to different salt containing diets to analyze changes in blood pressure and other cardiovascular parameters, urine excretion, and composition, as well as levels and expression of renin-angiotensin system components. Despite that KapBK rats excrete more urine and sodium, they have similar blood pressure as controls with the exception of a small increase in systolic blood pressure (SBP). However, they present decreased renal artery blood flow, increased intrarenal expression of angiotensinogen, and decreased mRNA expression of vasopressin V1A receptor (AVPR1A), suggesting a mechanism for the previously described reduction of renal vasopressin sensitivity by bradykinin. Additionally, reduced heart rate variability (HRV), increased cardiac output and frequency, and the development of cardiac hypertrophy are the main chronic effects observed in the cardiovascular system. In conclusion: (1) the transgenic KapBK rat is a useful model for studying chronic effects of bradykinin in kidney; (2) increased renal bradykinin causes changes in renin angiotensin system regulation; (3) decreased renal vasopressin sensitivity in KapBK rats is related to decreased V1A receptor expression; (4) although increased renal levels of bradykinin causes no changes in mean arterial pressure (MAP), it causes reduction in HRV, augmentation in cardiac frequency and output and consequently cardiac hypertrophy in rats after 6 months of age

    Perbandingan Pendekatan Tradisional dan Semantic Web untuk Akses Informasi Sebagai Penunjang Pengambilan Keputusan

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    Pengambilan keputusan pada dunia industry akan membutuhkan data teks, grafik dan juga bentuk data traditional lainnya. Dengan perkembangan teknologi informasi saat ini makasifat dari sumber informasi berkembang sehingga berjumlah sangat besar, keragaman jenis sumber informasi (sintaktik, struktur, semantic) dan data volume data semakin besar serta komplek

    Elevational Shifts in the Topographic Position of Polylepis Forest Stands in the Andes of Southern Peru

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     The patchy distribution of high-Andean treeline forests has provoked discussion aboutthe relative importance of anthropogenic and climatic causes of this pattern, both of whichvary with topography. We aimed to understand the topographic controls on the distribution ofPolylepis subsericans  treeline forests in the Andes of southern Peru, and the changes in these controlsalong an elevational gradient. We mapped Polylepis  forests in the Cordillera Urubamba, Cusco,using high-resolution aerial images and related forest cover to topographic variables extracted from adigital terrain model (30-m resolution). The variables were selected based on their expected biologicalrelevance for tree growth at high elevations. We constructed logistic regression models of forestcover, separately for each of five 100-m elevational belts. To deal with spatial autocorrelation, modelswere based on randomized 10% subsampling of the data with 1000 repetitions. The results suggest aconsistent shift in topographic preference with elevation, with forests at lower elevations showinga preference for topographically protected sites near rivers and forests at higher elevations beingincreasingly restricted to north-facing and well-drained sites. Our study offers the first indication ofthe ability of Andean treeline forests to benefit from the topographic heterogeneity of the high-Andes.Providing that dispersal and establishment are possible, local relocation between microsites could help these forests to persist regionally in spite of changing climatic conditions.</p

    Caloric Restriction Is More Efficient than Physical Exercise to Protect from Cisplatin Nephrotoxicity via PPAR-Alpha Activation

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    The antineoplastic drug cisplatin promotes renal injury, which limits its use. Protocols that reduce renal cisplatin toxicity will allow higher doses to be used in cisplatin treatment. Here, we compare physical exercise and caloric restriction (CR) as protocols to reduce cisplatin renal injury in mice. Male C57BL/6 were divided into four groups: Control, cisplatin, exercise + cisplatin, and 30% CR + cisplatin. Animals were injected with a single dose of cisplatin (20 mg/kg i.p.) and sacrificed 96 h after injection. Quantitative real time PCR, histological analyses, immunohistochemistry, and biochemical measurements were performed to investigate renal injury, necrosis, apoptosis, and inflammatory mechanisms. Both protocols protected against cisplatin renal injury, but CR was more effective in reducing uraemia and renal necrosis. The CR + Cisplatin group exhibited reduced serum IL-1 beta and INF-alpha levels. No differences were noted in the renal mRNA expression of cytokines. Both interventions reduced apoptosis, but only the CR + Cisplatin group decreased TNFR2 protein expression. PPAR-ci was activated in mice after CR. An antagonist of PPAR-alpha blocked the protective effect of CR. Both interventions attenuated the nephrotoxicity caused by cisplatin injection, but CR + Cisplatin showed a better response by modulating TNFR2. Moreover, part of the CR benefit depends on PPAR-alpha activation.FAPESP (Fundacao de Apoio a Pesquisa do Estado de Sao Paulo)CAPES/DAADUniv Fed Sao Paulo, Dept Biofis, Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Med, Disciplina Nefrol, Sao Paulo, BrazilUniv Sao Paulo, Inst Ciencias Biomed, Dept Immunol, Sao Paulo, BrazilUniv Sao Paulo, Dept Clin Med, Sao Paulo, BrazilUniv Fed Pelotas, Escola Nutr, Dept Nutr, Pelotas, BrazilMax Delbruck Ctr Mol Med, Berlin, GermanyUniv Fed Sao Paulo, Dept Biofis, Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Med, Disciplina Nefrol, Sao Paulo, BrazilFAPESP: 2013/06207-6FAPESP: 2015/20082-7CAPES/DAAD: 427/15Web of Scienc

    Kinin B(1) receptor deficiency leads to leptin hypersensitivity and resistance to obesity

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    OBJECTIVE-Kinins mediate pathophysiological processes related to hypertension, pain, and inflammation through the activation of two G-protein-coupled receptors, named B(1) and B(2). Although these peptides have been related to glucose homeostasis, their effects on energy balance are still unknown.RESEARCH DESIGN and METHODS-Using genetic and pharmacological strategies to abrogate the kinin B(1) receptor in different animal models of obesity, here we present evidence of a novel role for kinins in the regulation of satiety and adiposity.RESULTS-Kinin B(1) receptor deficiency in mice (B(1)(-/-)) resulted in less fat content, hypoleptinemia, increased leptin sensitivity, and robust protection against high-fat diet-induced weight gain. Under high-fat diet, B(1)(-/-) also exhibited reduced food intake, improved lipid oxidation, and increased energy expenditure. Surprisingly, B(1) receptor deficiency was not able to decrease food intake and adiposity in obese mice lacking leptin (ob/ob-B(1)(-/-)). However, ob/ob-B(1)(-/-) mice were more responsive to the effects of exogenous leptin on body weight and food intake, suggesting that B(1) receptors may be dependent on leptin to display their metabolic roles. Finally, inhibition of weight gain and food intake by B(1) receptor ablation was pharmacologically confirmed by long-term administration of the kinin B(1) receptor antagonist SSR240612 to mice under high-fat diet.CONCLUSIONS-Our data suggest that kinin B(1) receptors participate in the regulation of the energy balance via a mechanism that could involve the modulation of leptin sensitivity.Universidade Federal de SĂŁo Paulo, Dept Biophys, BR-04023062 SĂŁo Paulo, BrazilUniv Mogi das Cruzes, Mogi Das Cruzes, BrazilUniversidade Federal de SĂŁo Paulo, Dept Physiol, BR-04023062 SĂŁo Paulo, BrazilSanofi Aventis, Montpellier, FranceUniversidade Federal de SĂŁo Paulo, Dept Med, BR-04023062 SĂŁo Paulo, BrazilInst Natl Sante & Rech Med, Dept Renal & Cardiac Remodeling, U858 I2MR, Toulouse, FranceUniv Toulouse 3, Inst Med Mol Rangueil, F-31062 Toulouse, FranceInst Natl Rech Agron AgroParisTech, UMR914 Nutr Physiol & Ingest Behav, Paris, FranceMax Delbruck Ctr Mol Med, Berlin, GermanyUniversidade Federal de SĂŁo Paulo, Dept Biophys, BR-04023062 SĂŁo Paulo, BrazilUniversidade Federal de SĂŁo Paulo, Dept Physiol, BR-04023062 SĂŁo Paulo, BrazilUniversidade Federal de SĂŁo Paulo, Dept Med, BR-04023062 SĂŁo Paulo, BrazilWeb of Scienc

    Structure-based statistical analysis of transmembrane helices

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    Recent advances in determination of the high-resolution structure of membrane proteins now enable analysis of the main features of amino acids in transmembrane (TM) segments in comparison with amino acids in water-soluble helices. In this work, we conducted a large-scale analysis of the prevalent locations of amino acids by using a data set of 170 structures of integral membrane proteins obtained from the MPtopo database and 930 structures of water-soluble helical proteins obtained from the protein data bank. Large hydrophobic amino acids (Leu, Val, Ile, and Phe) plus Gly were clearly prevalent in TM helices whereas polar amino acids (Glu, Lys, Asp, Arg, and Gln) were less frequent in this type of helix. The distribution of amino acids along TM helices was also examined. As expected, hydrophobic and slightly polar amino acids are commonly found in the hydrophobic core of the membrane whereas aromatic (Trp and Tyr), Pro, and the hydrophilic amino acids (Asn, His, and Gln) occur more frequently in the interface regions. Charged amino acids are also statistically prevalent outside the hydrophobic core of the membrane, and whereas acidic amino acids are frequently found at both cytoplasmic and extra-cytoplasmic interfaces, basic amino acids cluster at the cytoplasmic interface. These results strongly support the experimentally demonstrated biased distribution of positively charged amino acids (that is, the so-called the positive-inside rule) with structural data
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