Anodic Behavior of Alloy 22 in Bicarbonate Media: Effect of Alloying

AbstractThe alloy 22 (UNS N06022) is one of the candidates for the manufacture of containers of radioactive waste high level. These containers provide services in natural environments characterized by multi-ionic solutions, it is estimated they could suffer three types of deterioration: general corrosion, localized corrosion (specifically crevice) and stress corrosion cracking (SCC). It has been confirmed to produce cracking, requires the presence of bicarbonate and chloride ions. It has also determined that susceptibility to SCC could be related to the occurrence of an anodic peak in the polarization curves in these media to at potentials previous transpassive zone.The aim of this work is to study the anodic behavior of alloy 22 and its alloying effect in different media containing bicarbonate and chloride ions in different concentrations and temperatures.Polarization curves were made of alloy 22 (Ni-22% Cr-13% Mo), Ni-Mo (Ni-28, 5% Mo) and Ni-Cr (Ni-20% Cr) under the following conditions: 1mol/L NaCl at 90°C, and 1.148mol/L NaHCO3, 1.148mol/L NaHCO3 + 1 mol/L NaCl, 1.148mol/L NaHCO3 + 0.1mol/L NaCl at 90°C, 75°C, 60°C and 25°C.It was found that the alloy 22 has a current peak in the anodic at potential previous to transpassive zone, only when the medium has bicarbonate ions. Curves performed in 1mol/L NaCl did not show any anodic peak, in any of the alloys tested. The curves made to alloys Ni-Mo and Ni-Cr in the media with bicarbonate ions, allowed to determine that Cr, is responsible for the appearance of the anodic peak in the Alloy 22. The curves of alloy B-3 showed no current peak in the conditions studied. The potential, at which the peak appears in the Alloy 22 and Ni-Cr alloy, increases with decreasing temperature. It also presents a variation of the peak with the composition of the solution. When the chloride ion is added to bicarbonate solution, the peak is shifted potential and higher current densities, depending on the concentration of added chloride ions

Meteorological-Based Predictions of Wheat Head Blight Epidemic in the Southern Argentinean Pampas Region

In Argentina, head blight is a highly risky disease (caused by Fusarium graminearum), although its occurrence is sporadic depending on prevalent environmental variables. These traits stimulated the development of predictive models of head blight occurrence which would help growers in the selection of control strategies. Empirical equations for predicting head blight incidence were developed at Pergamino (33° 56′ S, 60° 30′ W) associating temperature and moisture variables with mean disease data. Recently a new fundamental-empirical approach for estimating Fusarium index (incidence% x severity%/100) was developed using data of Pergamino and Marcos Juarez (32° 41′ S, 62°07′ W). In this study our objective was to validate both approaches at three more southern locations: La Dulce (38° 10′ S, 58° 00′ W), Miramar (38° 00′ S, 57° 33′ W) and Balcarce (37° 45′ S, 58° 18W), for the 2001 crop season. Examining partial and mean deviation values between observed and predicted incidence data, an underestimation especially at La Dulce was assessed. A clear improvement of incidence goodness of fit estimations was obtained decreasing the heat accumulation defining the length of the wheat critical period for infection. Employing this last critical period length for the fundamental-empirical approach led to satisfactory Fusarium index predictions. This study showed that both approaches developed at northern locations of the Pampas region can be portable and useful for predicting disease intensity at more southern locations, making only a few changes.Centro de Investigaciones en Fitopatologí

Perfil antropométrico de dos equipos universitarios de balonmano femenil

An important aspect of working in sports nutrition is the weight change and body composition. Many athletes need to minimize body fat and weight to improve the biomechanics aspects or increase muscle mass to improve performance. For this reason, the aim of our study was to determine the anthropometric profile of handball players of two college teams. They we made 17 basic anthropometric measurements to both teams. Team 1 obtained a mesomorphic-endomorphic phenotype and Team 2 obtained an endomorphic-mesomorphic phenotype. The mesomorphic component is predominant in both teams; therefore, it can be assumed that the skeletal muscle strength in female handball is decisiv

Apreciación general de la situación de la educación matemática en Latinoamérica con base en los informes nacionales: Comité Interamericano de Educación Matemática

Se hace un balance general sobre la educación matemática en los países latinoamericanos. Particularmente, se analizan algunos aspectos tales como: el currículum matemático en los niveles primario y medio; la formación y actualización de los docentes de matemática; los textos y publicaciones de tipo didáctico; la educación matemática en las universidades; el papel de las asociaciones de matemática en la región y las actividades extraescolares que se llevan a cabo en torno a la matemática

Phylogenetic and Morphologic Analyses of a Coastal Fish Reveals a Marine Biogeographic Break of Terrestrial Origin in the Southern Caribbean

Marine allopatric speciation involves interplay between intrinsic organismal properties and extrinsic factors. However, the relative contribution of each depends on the taxon under study and its geographic context. Utilizing sea catfishes in the Cathorops mapale species group, this study tests the hypothesis that both reproductive strategies conferring limited dispersal opportunities and an apparent geomorphologic barrier in the Southern Caribbean have promoted speciation in this group from a little studied area of the world.Mitochondrial gene sequences were obtained from representatives of the Cathorops mapale species group across its distributional range from Colombia to Venezuela. Morphometric and meristic analyses were also done to assess morphologic variation. Along a approximately 2000 km transect, two major lineages, Cathorops sp. and C. mapale, were identified by levels of genetic differentiation, phylogenetic reconstructions, and morphological analyses. The lineages are separated by approximately 150 km at the Santa Marta Massif (SMM) in Colombia. The northward displacement of the SMM into the Caribbean in the early Pleistocene altered the geomorphology of the continental margin, ultimately disrupting the natural habitat of C. mapale. The estimated approximately 0.86 my divergence of the lineages from a common ancestor coincides with the timing of the SMM displacement at approximately 0.78 my.Results presented here support the hypothesis that organismal properties as well as extrinsic factors lead to diversification of the Cathorops mapale group along the northern coast of South America. While a lack of pelagic larval stages and ecological specialization are forces impacting this process, the identification of the SMM as contributing to allopatric speciation in marine organisms adds to the list of recognized barriers in the Caribbean. Comparative examination of additional Southern Caribbean taxa, particularly those with varying life history traits and dispersal capabilities, will determine the extent by which the SMM has influenced marine phylogeography in the region

The role of protected areas in the avoidance of anthropogenic conversion in a high pressure region : a matching method analysis in the core region of the brazilian cerrado

Global efforts to avoid anthropogenic conversion of natural habitat rely heavily on the establishment of protected areas. Studies that evaluate the effectiveness of these areas with a focus on preserving the natural habitat define effectiveness as a measure of the influence of protected areas on total avoided conversion. Changes in the estimated effectiveness are related to local and regional differences, evaluation methods, restriction categories that include the protected areas, and other characteristics. The overall objective of this study was to evaluate the effectiveness of protected areas to prevent the advance of the conversion of natural areas in the core region of the Brazil’s Cerrado Biome, taking into account the influence of the restriction degree, governmental sphere, time since the establishment of the protected area units, and the size of the area on the performance of protected areas. The evaluation was conducted using matching methods and took into account the following two fundamental issues: control of statistical biases caused by the influence of covariates on the likelihood of anthropogenic conversion and the non-randomness of the allocation of protected areas throughout the territory (spatial correlation effect) and the control of statistical bias caused by the influence of auto-correlation and leakage effect. Using a sample design that is not based on ways to control these biases may result in outcomes that underestimate or overestimate the effectiveness of those units. The matching method accounted for a bias reduction in 94–99% of the estimation of the average effect of protected areas on anthropogenic conversion and allowed us to obtain results with a reduced influence of the auto-correlation and leakage effects. Most protected areas had a positive influence on the maintenance of natural habitats, although wide variation in this effectiveness was dependent on the type, restriction, governmental sphere, size and age group of the unit

Liver fibrosis secondary to bile duct injury: correlation of Smad7 with TGF-β and extracellular matrix proteins

<p>Abstract</p> <p>Background</p> <p>Liver fibrosis is the result of continuous liver injury stemming from different etiological factors. Bile duct injury induces an altered expression of TGF-β, which has an important role in liver fibrosis because this cytokine induces the expression of target genes such as collagens, PAI-1, TIMPs, and others that lead to extracellular matrix deposition. Smad7 is the principal inhibitor that regulates the target gene transcription of the TGF-β signaling. The aim of the study was to determine whether Smad7 mRNA expression correlates with the gene expression of <it>TGF-β, Col I</it>, <it>Col III</it>, <it>Col IV</it>, or <it>PAI-1 </it>in liver fibrosis secondary to bile duct injury (BDI).</p> <p>Results</p> <p>Serum TGF-β concentration was higher in BDI patients (39 296 pg/ml) than in liver donors (9008 pg/ml). Morphometric analysis of liver sections showed 41.85% of tissue contained fibrotic deposits in BDI patients. mRNA expression of Smad7, Col I, and PAI-1 was also significantly higher (<it>P </it>< 0.05) in patients with BDI than in controls. Smad7 mRNA expression correlated significantly with TGF-β concentration, Col I and Col III expression, and the amount of fibrosis.</p> <p>Conclusion</p> <p>We found augmented serum concentration of TGF-β and an increase in the percentage of fibrotic tissue in the liver of BDI patients. Contrary to expected results, the 6-fold increase in <it>Smad7 </it>expression did not inhibit the expression of <it>TGF-β, collagens</it>, and <it>PAI-1</it>. We also observed greater expression of Col I and Col III mRNA in BDI patients and significant correlations between their expression and TGF-β concentration and Smad7 mRNA expression.</p

Enfermedades crónicas

Adherencia al tratamiento farmacol&oacute;gico y relaci&oacute;n con el control metab&oacute;lico en pacientes con DM2Aluminio en pacientes con terapia de reemplazo renal cr&oacute;nico con hemodi&aacute;lisis en Bogot&aacute;, ColombiaAmputaci&oacute;n de extremidades inferiores: &iquest;est&aacute;n aumentando las tasas?Consumo de edulcorantes artificiales en j&oacute;venes universitariosC&oacute;mo crecen ni&ntilde;os normales de 2 a&ntilde;os que son sobrepeso a los 7 a&ntilde;osDiagn&oacute;stico con enfoque territorial de salud cardiovascular en la Regi&oacute;n MetropolitanaEfecto a corto plazo de una intervenci&oacute;n con ejercicio f&iacute;sico, en ni&ntilde;os con sobrepesoEfectos de la cirug&iacute;a bari&aacute;trica en pacientes con s&iacute;ndrome metab&oacute;lico e IMC &lt; 35 KG/M2Encuesta mundial de tabaquismo en estudiantes de profesiones de saludEnfermedades cr&oacute;nicas no transmisibles: Consecuencias sociales-sanitarias de comunidades rurales en ChileEpidemiolog&iacute;a de las muertes hospitalarias por patolog&iacute;as relacionadas a muerte encef&aacute;lica, Chile 2003-2007Estado nutricional y conductas alimentarias en adolescentes de 4&ordm; medio de la Regi&oacute;n de CoquimboEstudio de calidad de vida en una muestra del plan piloto para hepatitis CEvaluaci&oacute;n del proceso asistencial y de resultados de salud del GES de diabetes mellitus 2Factores de riesgo cardiovascular en poblaci&oacute;n universitaria de la Facsal, universidad de Tarapac&aacute;Implicancias psicosociales en la g&eacute;nesis, evoluci&oacute;n y tratamiento de pacientes con hipertensi&oacute;n arterial esencialInfarto agudo al miocardio (IAM): Realidad en el Hospital de Puerto Natales, 2009-2010Introducci&oacute;n de nuevas TIC y mejor&iacute;a de la asistencia a un programa de saludNi&ntilde;os obesos atendidos en el Cesfam de Puerto Natales y su entorno familiarPerfil de la mortalidad por c&aacute;ncer de cuello uterino en R&iacute;o de JaneiroPerfil del paciente primo-consultante del Programa de Salud Cardiovascular, Consultorio Cordillera Andina, Los AndesPrevalencia de automedicaci&oacute;n en mujeres beneficiarias del Hospital Comunitario de Til-TiPrevalencia de caries en poblaci&oacute;n preescolar y su relaci&oacute;n con malnutrici&oacute;n por excesoPrevalencia de retinopat&iacute;a diab&eacute;tica en comunas dependientes del Servicio de Salud Metropolitano Occidente (SSMOC)Problemas de adherencia farmacol&oacute;gica antihipertensiva en poblaci&oacute;n mapuche: Un estudio cualitativoRol biol&oacute;gico de los antioxidantes innatos en pacientes portadores de VIH/SidaSobrepeso en empleados de un restaurante de una universidad p&uacute;blica del estado de S&atilde;o Paul