Síntesis y caracterización fisicoquímica de circonia promovida con ácido tungstofosfórico y ácido bórico utilizada como catalizador en la isomerización de n-pentano

En este trabajo se muestra la preparación, caracterización y evaluación de la actividad catalítica de materiales del tipo ZrO2 promovida con ácido tungstofosfórico y ácido bórico. El Zr(OH)4 se sintetizó por el método sol-gel utilizando como precursores al n-butóxido de circonio y 1-butanol, manteniendo un pH = 8 durante la síntesis. El Zr(OH)4 se impregnó con un 15% en pesodel agente ácido, calcinado a 600 ºC e impregnado  posteriormente con 0,5% en peso de platino. Se observó que los iones [PW12O40]3– y [BO3]3– permanecen fuertementeenlazados a la superficie de la ZrO2 inhibiendo el crecimiento de la partícula, retardando la sinterización del material y la aparición de la fase monoclínica.Además, con la incorporación de estos dopantes se incrementó la acidez total del material, específicamente la población de sitios ácidos fuertes, siendo este tipo de sitios los predominantes en las muestras acidificadas.La acidez desarrollada por los materiales fue la adecuada para lograr catalizar la reacción de isomerización de n-pentano con conversiones superiores al 20% y selectividades hacia el isopentano que fluctuaron alrededor del 90%

Maternal imprinting on cognition markers of wild type and transgenic Alzheimer's disease model mice

The risk of suffering from Alzheimer’s disease (AD) is higher in individuals from AD-affected mothers. The purpose of this investigation was to study whether maternal transmission might produce AD-related alterations in progenies of mice that do not have any genotypic alteration. We used cognitively-intact mothers harbouring in heterozygosity the transgene for overexpressing the Swedish double mutant version of the human amyloid precursor protein (hAβPPswe). The phenotype of the offspring with or without the transgene resulting from crossing young Tg2576 females with wild-type males were compared with those of the offspring resulting from crossing wild-type females with Tg2576 males. The hAβPPswe-bearing offspring from Tg2576 mothers showed an aggravated AD-like phenotype. Remarkably, cognitive, immunohistochemical and some biochemical features displayed by Tg2576 heterozygous mice were also found in wild-type animals generated from Tg2576 females. This suggests the existence of a maternal imprinting in the wild-type offspring that confers a greater facility to launch an AD-like neurodegenerative cascade. Such progeny, lacking any mutant amyloid precursor protein, constitutes a novel model to study maternal transmission of AD and, even more important, to discover early risk markers that predispose to the development of AD

Bilingualism alters children’s frontal lobe functioning for attentional control

Bilingualism is a typical linguistic experience, yet relatively little is known about its impact on children’s cognitive and brain development. Theories of bilingualism suggest that early dualâ language acquisition can improve children’s cognitive abilities, specifically those relying on frontal lobe functioning. While behavioral findings present much conflicting evidence, little is known about its effects on children’s frontal lobe development. Using functional nearâ infrared spectroscopy (fNIRS), the findings suggest that Spanishâ English bilingual children (n = 13, ages 7â 13) had greater activation in left prefrontal cortex during a nonâ verbal attentional control task relative to ageâ matched English monolinguals. In contrast, monolinguals (n = 14) showed greater right prefrontal activation than bilinguals. The present findings suggest that early bilingualism yields significant changes to the functional organization of children’s prefrontal cortex for attentional control and carry implications for understanding how early life experiences impact cognition and brain development.This fNIRS study investigated the impact of bilingual exposure on children’s brain organization for attentional control (N = 27, ages 7â 13). During a nonâ verbal attention task, bilinguals showed greater left frontal lobe activation than monolinguals. Monolinguals showed greater right frontal lobe activation than bilinguals. The findings suggest that bilingualism affects the functionality of children’s left prefrontal cortex for attentional control.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136694/1/desc12377-sup-0001-FigS1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136694/2/desc12377.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136694/3/desc12377_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136694/4/desc12377-sup-0003-SupInfo.pd

Experimental Study of the Shortest Reset Word of Random Automata

In this paper we describe an approach to finding the shortest reset word of a finite synchronizing automaton by using a SAT solver. We use this approach to perform an experimental study of the length of the shortest reset word of a finite synchronizing automaton. The largest automata we considered had 100 states. The results of the experiments allow us to formulate a hypothesis that the length of the shortest reset word of a random finite automaton with $n$ states and 2 input letters with high probability is sublinear with respect to $n$ and can be estimated as $1.95 n^{0.55}.

Two-proton correlations from 158 AGeV Pb+Pb central collisions

The two-proton correlation function at midrapidity from Pb+Pb central collisions at 158 AGeV has been measured by the NA49 experiment. The results are compared to model predictions from static thermal Gaussian proton source distributions and transport models RQMD and VENUS. An effective proton source size is determined by minimizing CHI-square/ndf between the correlation functions of the data and those calculated for the Gaussian sources, yielding 3.85 +-0.15(stat.) +0.60-0.25(syst.) fm. Both the RQMD and the VENUS model are consistent with the data within the error in the correlation peak region.Comment: RevTeX style, 6 pages, 4 figures, 1 table. More discussion are added about the structure on the tail of the correlation function. The systematic error is revised. To appear in Phys. Lett.

Event-by-event fluctuations of average transverse momentum in central Pb+Pb collisions at 158 GeV per nucleon

We present first data on event-by-event fluctuations in the average transverse momentum of charged particles produced in Pb+Pb collisions at the CERN SPS. This measurement provides previously unavailable information allowing sensitive tests of microscopic and thermodynamic collision models and to search for fluctuations expected to occur in the vicinity of the predicted QCD phase transition. We find that the observed variance of the event-by-event average transverse momentum is consistent with independent particle production modified by the known two-particle correlations due to quantum statistics and final state interactions and folded with the resolution of the NA49 apparatus. For two specific models of non-statistical fluctuations in transverse momentum limits are derived in terms of fluctuation amplitude. We show that a significant part of the parameter space for a model of isospin fluctuations predicted as a consequence of chiral symmetry restoration in a non-equilibrium scenario is excluded by our measurement.Comment: 6 pages, 2 figures, submitted to Phys. Lett.

Biofertilizante y su Correlación entre Parámetros Productivos y de Calidad en Limón Sutil (Citrus aurantifolia Swingle)

El limón sutil es un cultivo de alta demanda e importancia en el desarrollo socioeconómico en Perú, empleándose mayormente fertilizantes inorgánicos que generan incrementos constantes en los costos de producción, siendo necesario el uso de alternativas orgánicas e inocuas para su producción. El objetivo fue evaluar el efecto de diferentes dosis de biol o biofertilizante, y su correlación en los parámetros productivos y de calidad en el cultivo de limón sutil. Se evaluaron cuatro tratamientos: T0 (testigo: manejo convencional), T1 (Biol 10%), T2 (Biol 20%) y T3 (Biol 30%) aplicados cada 15 días, evaluando los siguientes parámetros: 1) productivos: diámetro del fruto (DF), grosor de cáscara (GC), peso del fruto (PF), rendimiento por ha (RHa) y 2) calidad: acidez (AD), porcentaje de sólidos solubles (PSS), pH, zumo o jugo de limón (ZL). Se realizó análisis de correlación, análisis de componentes principales-ACP, un ANOVA, y se analizó la relación Beneficio/Costo. En el ACP se obtuvo dos componentes: C1 (71.40%) y C2 (11.80%) explicando el 83.20% de la variabilidad. El C1 explica la mayor variabilidad y agrupó variables: G-I (ZL, AD), G-II (DF, GC, PSS) y GIII (PF, RHa). Los tratamientos con Biol 10%, 20%, 30% en ZL, AD (G-I) presentaron los mejores resultados (P < 0.05); el T2 presentó los mayores valores de PF y RHa, y fue el tratamiento más rentable (B/C=3.84). El Biofertilizante es una alternativa para reducir el uso de fertilizantes sintéticos y los costos de producción. El biofertilizante al 20% resultó más rentable y mejoró variables evaluadas

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02

Primrose syndrome: Characterization of the phenotype in 42 patients

Primrose syndrome (PS; MIM# 259050) is characterized by intellectual disability (ID), macrocephaly, unusual facial features (frontal bossing, deeply set eyes, down-slanting palpebral fissures), calcified external ears, sparse body hair and distal muscle wasting. The syndrome is caused by de novo heterozygous missense variants in ZBTB20. Most of the 29 published patients are adults as characteristics appear more recognizable with age. We present 13 hitherto unpublished individuals and summarize the clinical and molecular findings in all 42 patients. Several signs and symptoms of PS develop during childhood, but the cardinal features, such as calcification of the external ears, cystic bone lesions, muscle wasting, and contractures typically develop between 10 and 16 years of age. Biochemically, anemia and increased alpha-fetoprotein levels are often present. Two adult males with PS developed a testicular tumor. Although PS should be regarded as a progressive entity, there are no indications that cognition becomes more impaired with age. No obvious genotype-phenotype correlation is present. A subgroup of patients with ZBTB20 variants may be associated with mild, nonspecific ID. Metabolic investigations suggest a disturbed mitochondrial fatty acid oxidation. We suggest a regular surveillance in all adult males with PS until it is clear whether or not there is a truly elevated risk of testicular cancer.This article is freely available via Open Access. Click on the Publisher URL to access it via the publisher's site.published version, accepted version (12 month embargo) submitted versio