Vanadium in animal drinking water of dairy farms from Southeast Córdoba, Argentina

En este trabajo se cuantificaron los niveles de vanadio presentes en el agua de bebida animal de25 establecimientos lecheros, ubicados en el departamento de Unión, sudeste de la provinciade Córdoba, Argentina. Además, se cuantificaron sólidos totales disueltos (STD) e ionesmayoritarios, a fin de determinar la calidad del agua con la que se abastecen los tambos relevados.A partir de los datos analizados, se evidenció que el 48% de los mismos se abastece de la capafreática, cuya calidad es inferior al agua proveniente de pozos más profundos. Asimismo seobservó que la totalidad de las muestras de nivel freático superaban los valores máximos devanadio recomendados para agua de bebida animal, alcanzándose niveles superiores a los 6mg/L; y que las muestras con los niveles más bajos de vanadio presentaban, en contraposición,concentraciones elevadas de cloruros y sulfatos. Respecto de las aguas provenientes de pozossemisurgentes, menos del 10% de las muestras presentaban niveles de vanadio superiores a losestablecidos, no alcanzándose en ningún caso valores por encima de los 0,3 mg/L. El presenteestudio sugiere entonces que el agua procedente de la capa freática no sería segura paraaprovisionamiento de los animales.In this paper, vanadium levels, in animal drinking water, were quantified in water samples from 25 dairy farms located in the department of Union, southeast of the province of Cordoba, Argentina. In addition, total dissolved solids (TDS) and major ions were considered in order to determine the quality of water source used for livestock. Analyzed data showed that 48% of farms use a groundwater from the freatic aquifer (3 to 15 m), for animal drinking water, whose quality is worst than water from deeper wells (80 to 120 m). It was also noted that all the samples from the freatic aquifer exceeded the maximum vanadium levels considered for animal drinking water, reaching more than 6 mg/L. Regarding the water from deeper wells, less than 10% of them have vanadium concentrations above the recommended level, presenting a maximum level of 0.3 mg/L. The present study suggests that the water from the freatic aquifer would not be safe for use as water for livestock drinking; because of the levels of vanadium, arsenic, fluoride, chloride and sulphate.Fil: Pérez Carrera, Alejo Leopoldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Unidad Ejecutora de Investigaciones en Produccion Animal; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Centro de Estudios Transdisciplinarios del Agua; ArgentinaFil: Alvarez Gonçalvez, C. V.. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Centro de Estudios Transdisciplinarios del Agua; ArgentinaFil: Fernandez Cirelli, Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Unidad Ejecutora de Investigaciones en Produccion Animal; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Centro de Estudios Transdisciplinarios del Agua; Argentin

EL REGALO FISCAL EN LA DECISIÓN TEMPORAL DE CASARSE. UNA PRIMERA APROXIMACIÓN EMPÍRICA

En este trabajo nos preguntamos si a lo largo de la década de los noventa las parejas españolas decidieron la fecha de su matrimonio descontando el importante beneficio fiscal que suponía optimizar el fraccionamiento del período impositivo en el IRPF. El planteamiento teórico realizado nos indica que los agentes, bajo determinados supuestos, deberían realizar un ejercicio de planificación fiscal ya que, con la legislación vigente desde el ejercicio 1.988 a 1.999, era posible encontrar un período óptimo para casarse. Sin embargo, la evidencia que se desprende de los datos de series temporales sugiere que nuestro impuesto sobre la renta no ha tenido, a diferencia de algunos países anglosajones, un efecto significativo en la distribución mensual de los matrimonios, aunque se puede percibir un pequeño efecto aprendizaje de la norma. Una explicación que avanzamos para este fenómeno reside en la escasa información ex-ante a la boda para minimizar el coste tributario de la fecha de celebración, y en que son otro tipo de variables de índole social y cultural las que tienen un mayor peso en la decisión de casarse.Impuesto sobre la renta, planificación fiscal, decisión temporal de casarse.

Characterization of Microstructural and Mechanical Properties of 17-4 PH Stainless Steel by Cold Rolled and Machining vs. DMLS Additive Manufacturing

The 17-4 PH stainless steel is widely used in the aerospace, petrochemical, chemical, food, and general metallurgical industries. The present study was conducted to analyze the mechanical properties of two types of 17-4 PH stainless steel—commercial cold-rolled and direct metal laser sintering (DMLS) manufactured. This study employed linear and nonlinear tensile FEM simulations, combined with various materials characterization techniques such as tensile testing and nanoindentation. Moreover, microstructural analysis was performed using metallographic techniques, optical microscopy, scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). The results on the microstructure for 17-4 PH DMLS stainless steel reveal the layers of melting due to the laser process characterized by complex directional columnar structures parallel to the DMLS build direction. The mechanical properties obtained from the simple tension test decreased by 17% for the elastic modulus, 7.8% for the yield strength, and 7% for the ultimate strength for 17-4 PH DMLS compared with rolled 17-4 PH stainless steel. The FEM simulation using the experimental tension test data revealed that the 17-4 PH DMLS stainless steel experienced a decrease in the yield strength of ~8% and in the ultimate strength of ~11%. A reduction of the yield strength of the material was obtained as the grain size increased

Microstructural differences in the thalamus and thalamic radiations in the congenitally deaf

There is evidence of both crossmodal and intermodal plasticity in the deaf brain. Here, we investigated whether sub-cortical plasticity, specifically of the thalamus, contributed to this reorganisation. We contrasted diffusion weighted magnetic resonance imaging data from 13 congenitally deaf and 13 hearing participants, all of whom had learnt British Sign Language after 10 years of age. Connectivity based segmentation of the thalamus revealed changes to mean and radial diffusivity in occipital and frontal regions, which may be linked to enhanced peripheral visual acuity, and differences in how visual attention is deployed in the deaf group. Using probabilistic tractography, tracts were traced between the thalamus and its cortical targets, and microstructural measurements were extracted from these tracts. Group differences were found in microstructural measurements of occipital, frontal, somatosensory, motor and parietal thalamo-cortical tracts. Our findings suggest there is sub-cortical plasticity in the deaf brain, and that white matter alterations can be found throughout the deaf brain, rather than being restricted to, or focussed in auditory cortex

Autonomic impairment of patients in coma with different Glasgow coma score assessed with heart rate variability

Primary objective: The objective of this study is to assess the functional state of the autonomic nervous system in healthy individuals and in individuals in coma using measures of heart rate variability (HRV) and to evaluate its efficiency in predicting mortality. Design and Methods: Retrospective group comparison study of patients in coma classified into two subgroups, according to their Glasgow coma score, with a healthy control group. HRV indices were calculated from 7 min of artefact-free electrocardiograms using the Hilbert–Huang method in the spectral range 0.02–0.6 Hz. A special procedure was applied to avoid confounding factors. Stepwise multiple regression logistic analysis (SMLRA) and ROC analysis evaluated predictions. Results: Progressive reduction of HRV was confirmed and was associated with deepening of coma and a mortality score model that included three spectral HRV indices of absolute power values of very low, low and very high frequency bands (0.4-0.6 Hz). The SMLRA model showed sensitivity of 95.65%, specificity of 95.83%, positive predictive value of 95.65%, and overall efficiency of 95.74%. Conclusions: HRV is a reliable method to assess the integrity of the neural control of the caudal brainstem centres on the hearts of patients in coma and to predict patient mortality