Decoupling of arsenic and iron release from ferrihydrite suspension under reducing conditions: a biogeochemical model

High levels of arsenic in groundwater and drinking water are a major health problem. Although the processes controlling the release of As are still not well known, the reductive dissolution of As-rich Fe oxyhydroxides has so far been a favorite hypothesis. Decoupling between arsenic and iron redox transformations has been experimentally demonstrated, but not quantitatively interpreted. Here, we report on incubation batch experiments run with As(V) sorbed on, or co-precipitated with, 2-line ferrihydrite. The biotic and abiotic processes of As release were investigated by using wet chemistry, X-ray diffraction, X-ray absorption and genomic techniques. The incubation experiments were carried out with a phosphate-rich growth medium and a community of Fe(III)-reducing bacteria under strict anoxic conditions for two months. During the first month, the release of Fe(II) in the aqueous phase amounted to only 3% to 10% of the total initial solid Fe concentration, whilst the total aqueous As remained almost constant after an initial exchange with phosphate ions. During the second month, the aqueous Fe(II) concentration remained constant, or even decreased, whereas the total quantity of As released to the solution accounted for 14% to 45% of the total initial solid As concentration. At the end of the incubation, the aqueous-phase arsenic was present predominately as As(III) whilst X-ray absorption spectroscopy indicated that more than 70% of the solid-phase arsenic was present as As(V). X-ray diffraction revealed vivianite Fe(II)3(PO4)2.8H2O in some of the experiments. A biogeochemical model was then developed to simulate these aqueous- and solid-phase results. The two main conclusions drawn from the model are that (1) As(V) is not reduced during the first incubation month with high Eh values, but rather re-adsorbed onto the ferrihydrite surface, and this state remains until arsenic reduction is energetically more favorable than iron reduction, and (2) the release of As during the second month is due to its reduction to the more weakly adsorbed As(III) which cannot compete against carbonate ions for sorption onto ferrihydrite. The model was also successfully applied to recent experimental results on the release of arsenic from Bengal delta sediments

Uso de cuentos creativos y su relación con el desarrollo de la expresión verbal de los niños de 5 años de la I.E.I Medallita Milagrosa Huaura 2013

El trabajo: “Uso de cuentos creativos y su relación con el desarrollo de la expresión verbal de los niños de 5 años de la I.E.I Medallita milagrosa Huaura - 2013”, es una investigación que busca la relación entre los cuentos creativos y el desarrollo de la expresión verbal, siendo conocedores de la educación actual es muy distinta a lo que era en años anteriores, por lo tanto, las maneras y forma de enseñar cambian constantemente y los docentes deben actualizarse y adaptarse a ellas. Las técnicas empleadas facilitaron la obtención de los resultados que mostramos en esta investigación, la siguiente investigación es de representación fundamental y de categoría descriptiva. La investigación tiene una muestra de 36 niños de educación inicial, la herramienta aplicada fue el de encuesta por preguntas. Las respuestas confirman la hipótesis de la relación del uso de los cuentos creativos y la relación con el desarrollo de la expresión verdad en los niños de 5 años de la institución educativa inicial Medallita milagrosa Huaura. La correlación es de intensidad moderada para este trabajo de investigació

Shape-Dependent Thermodynamics and Non-Local Hydrodynamics in a Non-Gibbsian Steady-State of a Drift-Diffusion System

Shape-dependent thermodynamics and non-local hydrodynamics are argued to occur in dissipative steady states of driven diffusive systems. These predictions are confirmed by numerical simulations. Unlike power-law correlations, these phenomena cannot be explained by a hypothesis of ``criticality''. Instead, they require the effective Hamiltonian of the system to contain very long-range potentials, making the invariant probability measures formally ``non-Gibbsian''.Comment: 4 pages, Latex Version 2.09, 1 Postscript figur

Behavior of low birth weight in Imia’s town, Guantanamo province

Se realizó un estudio en el Policlínico Universitario "Ciro Frías Cabrera", del municipio Imías, provincia Guantánamo, durante el periodo enero 2010 a diciembre 2012, con el objetivo de caracterizar el comportamiento de bajo peso al nacer. El universo de estudio estuvo constituido por 957 nacidos vivos, de los cuales se selecciona una muestra de 59 niños. Una vez obtenida la información los datos fueron introducidos y procesados de forma manual, resumiéndose en variables estudiadas cuantitativas y cualitativas, que le dieron salida a los objetivos propuestos. Como principales resultados se obtuvieron los siguientes: el índice de bajo peso al nacer tuvo una tendencia a incrementarse en los años de estudio, predominaron los partos pretérminos, con un peso promedio superior a los 2 000 g, cuyas madres en su mayoría, al momento del parto, tenían edades entre los 20 y los 35 años. Prevalecieron los niños bajo peso al nacer, cuyas mujeres tuvieron durante el embarazo sepsis vaginal.A study is done at the Policlinic "Ciro Frías Cabrera" Imías Township, Guantanamo province, from January 2010 to December 2012 with the aim of characterizing the behavior of low birth weight. The studied group consists of 957 low births, which is selected a sample of 59 Children. The information and data are entered manually processed and summarized in quantitative and qualitative variables, very important to the proposed objectives. The rate of low birth weight has a tendency to increase in the years of study, preterm births were predominated, with more than 2 000 g, average weight whose mothers mostly had at the time of birth: the following main results were obtained delivery, with age between 20 and 35 years, prevailing low birth weight children, whose women had vaginal sepsis during pregnancy

MODELO DE ENFERMEDAD RENAL NO TRADICIONAL EN RATONES C57BL/6 SOMETIDOS A DESHIDRATACIÓN Y ALTAS TEMPERATURAS

The epidemic of non-traditional chronic kidney disease (CKDnt) present in the Pacific Ocean coast along Central America has been related to exposure to high temperature and recurrent dehydration. This study proposed an experimental model of CKDnT caused by heat stress and dehydration by evaluating several cardiovascular and biochemical parameters in rodents. Treated mice (GTdH) were subjected to recurrent dehydration induced by exposure to high temperature for 8 hours, for one week; contrary to the control group (CG) which was maintained under standard conditions. For both groups, control (CG) and GTdH, no significant changes in body weight, water consumption, feed consumption, and plasma glycemia values were demonstrated. About cardiovascular parameters in both groups of animals, no significant differences were found in heart rate, diastolic, and mean arterial pressure; however, in the GTdH, a significant increase in systolic arterial pressure was observed in comparison with the CG (123.9±12.3 vs.102.8±12.9 mmHg; p<0.05). Important findings found in the GTdH were hematuria and a decrease in the organ weight/body weight ratio. The set of results obtained allows us to demonstrate that heat stress and dehydration are conditions that accelerate the processes that precede renal damage and therefore these factors could be used experimentally for future studies on CKDnT.La epidemia de la enfermedad renal crónica no tradicional (ERCnT) presente en la costa del Océano Pacífico a lo largo de Centroamérica se ha relacionado con la exposición a altas temperaturas y a la deshidratación recurrente. En este estudio se propone un modelo experimental de ERCnT provocada por estrés térmico y deshidratación valorando diversos parámetros cardiovasculares y bioquímicos en los roedores. Los ratones tratados (GTdH) fueron sometidos a deshidratación recurrente inducida por exposición a alta temperatura durante 8 horas, por una semana; contrario al grupo control (GC) que se mantuvo en condiciones estándares. Para ambos grupos, control (GC) y GTdH, no se evidenciaron cambios significativos en cuanto al peso corporal, consumo de agua, consumo de alimento y valores de glicemia plasmática. En relación con los parámetros cardiovasculares, entre los grupos evaluados no se encontraron diferencias significativas en frecuencia cardiaca, presión arterial diastólica y media; sin embargo, en el GTdH se observó un incremento significativo de la presión arterial sistólica en comparación con el GC (123.9?12.3 vs.102.8?12.9 mmHg; p<0.05). Hallazgos importantes encontrados en el GTdH fueron la hematuria y una disminución de la relación peso de órganos/peso corporal. El conjunto de resultados obtenidos permite evidenciar que el estrés térmico y la deshidratación son condiciones que aceleran los procesos que preceden al daño renal y que por ende estos factores podrían emplearse experimentalmente para futuros estudios sobre la ERCnT

Lupus Eritematoso Sistémico en Paciente Masculino de 48 Años con Antecedentes Patológicos de Importancia. Reporte de Caso

Systemic lupus erythematosus is a multisystem autoimmune disease, with great variability in its manifestation and course. It presents with constitutional symptoms, such as fever, weight loss, fatigue, hair loss, and evidence of diffuse inflammation, such as lymphadenopathy and hepatosplenomegaly. Conditions on the skin, musculoskeletal system and kidney are common, but it can also affect the myocardium and gastrointestinal system. The etiology is not fully clarified; However, it is known that there is a variable production of autoantibodies that, together with genetic and environmental factors, may be involved in its pathogenesis The case of a 48-year-old male patient with a significant history is reported, who came to the clinic because of joint pain in the proximal and distal phalanges for 1 month, 5/10 on the VAS scale, inflammatory type, without irradiation, attenuates with movements and with morning-predominant stiffness; Concomitantly, for the past 48 hours, there has been an unquantified rise in temperature; In addition, he presents macular-type canker sores, erythematous, non-painful, 3-4 mm long, and for approximately 24 hours he has been vomiting liquid content on two occasions, which makes it difficult to eat food.El Lupus eritematoso sistémico es una enfermedad autoinmunitaria multisistémica, con gran variabilidad en su manifestación y curso. Se manifiesta con síntomas constitucionales, como fiebre, pérdida de peso, fatiga, pérdida de cabello y evidencia de inflamación difusa, como linfadenopatía y hepatoesplenomegalia. La afección en la piel, en el sistema musculoesquelético y en el renal es común, pero también puede afectar al miocardio y al aparato gastrointestinal. La etiología no está totalmente aclarada; sin embargo, se sabe que existe una producción variable de autoanticuerpos que, unida a factores genéticos y ambientales, puede estar implicada en su patogenia. Se Reporta el caso de un paciente masculino de 48 años con antecedentes de importancia, que acude a consulta por presentar desde hace 1 meses dolor articular en falanges proximales y distales, 5/10 en la escala de EVA, tipo inflamatorio, sin irradiación, se atenúa con los movimientos y con rigidez de predominio matutino; concomitantemente desde hace 48 horas presenta alza térmica no cuantificada; además, presenta aftas de tipo macular, eritematosas, no dolorosas, largas de 3-4 mm y desde hace aproximadamente 24 horas refiere vómito de contenido líquido por dos ocasiones, lo que dificulta la ingesta de alimentos

Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

Hunt for new phenomena using large jet multiplicities and missing transverse momentum with ATLAS in 4.7 fb−1 of s√=7TeV proton-proton collisions

Results are presented of a search for new particles decaying to large numbers of jets in association with missing transverse momentum, using 4.7 fb−1 of pp collision data at s√=7TeV collected by the ATLAS experiment at the Large Hadron Collider in 2011. The event selection requires missing transverse momentum, no isolated electrons or muons, and from ≥6 to ≥9 jets. No evidence is found for physics beyond the Standard Model. The results are interpreted in the context of a MSUGRA/CMSSM supersymmetric model, where, for large universal scalar mass m 0, gluino masses smaller than 840 GeV are excluded at the 95% confidence level, extending previously published limits. Within a simplified model containing only a gluino octet and a neutralino, gluino masses smaller than 870 GeV are similarly excluded for neutralino masses below 100 GeV

Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal