Thermodynamics of primitive model electrolytes in the symmetric and modified Poisson-Boltzmann theories. A comparative study with Monte Carlo simulations

Osmotic coefficients, individual and mean activity coefficients of primitive model electrolyte solutions are computed at different molar concentrations using the symmetric Poisson-Boltzmann and modified Poisson-Boltzmann theories. The theoretical results are compared with an extensive series of Monte Carlo simulation data obtained by Abbas et al. [Fluid Phase Equilib., 2007, 260, 233; J. Phys. Chem. B, 2009, 113, 5905]. The agreement between modified Poisson-Boltzmann predictions with the "exact" simulation results is almost quantitative for monovalent salts, while being semi-quantitative or better for higher and multivalent salts. The symmetric Poisson-Boltzmann results, on the other hand, are very good for monovalent systems but tend to deviate at higher concentrations and/or for multi-valent systems. Some recent experimental values for activity coefficients of HCl solution (individual and mean activities) and NaCl solution (mean activity only) have also been compared with the symmetric and modified Poisson-Boltzmann theories, and with the Monte Carlo simulations.Comment: 10 pages, 9 figure

Posibilidades para la producción y el almacenamiento de coliflor (Brassica oleracea var. botrytis) y lechuga (Lactuca sativa L.)

Coliflor-Brassica oleraceaLechuga-Lactuca sativ

Is fetal gender associated with adverse perinatal outcome in intrauterine growth restriction (IUGR)?

OBJECTIVE: The purpose of this study was to determine if there is a difference in perinatal outcome by gender among growth-restricted fetuses. STUDY DESIGN: This was a retrospective cohort study of intrauterine growth restriction (IUGR) singleton pregnancies over a 5-year period. Clinical outcomes compared by gender included preterm delivery, perinatal mortality (PNM), respiratory distress syndrome (RDS), grade 3 or 4 intraventricular hemorrhage (IVH), necrotizing enterocolitis (NEC), and periventricular leukomalacia (PVL). Statistical analysis included bivariate and multivariable techniques. RESULTS: Seven hundred and twenty-seven singleton pregnancies with IUGR were identified. Three hundred and forty-six (47.6%) were males. Birth weight was similar between the groups. After adjusting for maternal demographics, medical history, gestational age, mode of delivery, and antenatal corticosteroids, adverse perinatal outcomes were similar between the groups. Severity of outcomes was also similar between males and females (P = .66). CONCLUSION: Male fetuses with IUGR have similar outcomes when compared with female IUGR fetuses. Gender does not play a role in perinatal outcome in the setting of fetal growth restriction

GROWTH MINDSET IN ENGLISH LANGUAGE LEARNING OF COLLEGE STUDENTS

This study investigated the growth mindset of college students in English language learning and the challenges they encounter in an online setting. Using a researcher-made questionnaire about the growth mindset of college students in English language learning and the challenges they encounter in an online setting, data from the 60 respondents in the study coming from the different colleges or departments of the Notre Dame of Midsayap College were analyzed quantitatively. Findings indicated that students have a high growth mindset and that factors such as motivation, criticism, environment, and effort had played a major role in their English language learning. Major challenges of students in an online setting include finding difficulty in accessing online materials due to poor internet connection, experiencing headaches and body pains due to prolonged exposure to gadgets, and getting bored easily when class time is too lengthy. The least challenges encountered by students in an online setting yet also hampered their learning are lacking gadgets such as a cellphone and laptops, feeling disconnected from the instructor, and excessive workloads. Furthermore, there is no significant difference in a growth mindset in terms of sex and college or department. However, it was found out that College of Nursing (CN) got the highest mean when it comes to their growth mindset. Meanwhile, College of Information Technology, and Engineering (CITE) got the lowest mean. Moreover, there is a significant relationship between the growth mindset of English language learning and the challenges they encountered in an online setting.  Article visualizations

Influencia del “bullying” y el “ciberbullying” en la motivación de los estudiantes de secundaria y su efecto en el rendimiento académico

El acoso escolar es una alarmante realidad en nuestra sociedad. Cuando hablamos de “bullying” nos referimos a situaciones en las que uno o más estudiantes persiguen e intimidan a otro/a por medio de insultos, rumores, humillaciones, aislamiento social, sobrenombres, agresiones físicas, amenazas y coacciones, pudiendo desarrollarse a lo largo de meses e incluso años, evolucionando en “ciberbullying” que hace referencia a una forma de agresión a través de las tecnologías, siendo sus consecuencias devastadoras tanto a nivel social como personal. Por eso la comunidad educativa no puede obviar estas situaciones y tomar conciencia para dar soluciones y procurar prevenirlo.El objetivo principal de este trabajo es diseñar una herramienta para determinar si el acoso escolar, ya sea en posición de víctima o agresor, es el factor determinante de la falta de motivación y el bajo rendimiento académico de los estudiantes en las escuelas de Educación Secundaria en Puerto Rico. A tal fin, se creará un cuestionario para maestros y otro para estudiantes, tanto de la corriente regular como de educación especial, para atender la necesidad y ayudar a entender realmente cuales son los factores asociados al problema objeto de estudio. Eso será precisamente lo que se presente en este artículo, el cuestionario elaborado y ya validado por criterio de jueces expertos y que tras su implementación y la obtención de los resultados servirá para presentar un modelo de intervención para estudiantes y profesorado que pretende potenciar la motivación y el rendimiento escolar de los estudiantes sobre todo cuando son víctimas de acoso escolar en cualquiera de sus modalidades

Genetic control of plasticity in root morphology and anatomy of rice in response to water deficit

Elucidating the genetic control of rooting behavior under water-deficit stress is essential to breed climate-robust rice (Oryza sativa) cultivars. Using a diverse panel of 274 indica genotypes grown under control and water-deficit conditions during vegetative growth, we phenotyped 35 traits, mostly related to root morphology and anatomy, involving 45,000 root-scanning images and nearly 25,000 cross sections from the root-shoot junction. The phenotypic plasticity of these traits was quantified as the relative change in trait value under water-deficit compared with control conditions. We then carried out a genome-wide association analysis on these traits and their plasticity, using 45,608 high-quality single-nucleotide polymorphisms. One hundred four significant loci were detected for these traits under control conditions, 106 were detected under water-deficit stress, and 76 were detected for trait plasticity. We predicted 296 (control), 284 (water-deficit stress), and 233 (plasticity) a priori candidate genes within linkage disequilibrium blocks for these loci. We identified key a priori candidate genes regulating root growth and development and relevant alleles that, upon validation, can help improve rice adaptation to water-deficit stress. (Résumé d'auteur

EDXRF study of Tupi-Guarani archaeological ceramics.

A set of indian Brazilian pottery fragments belonging to Tupi-Guarani tradition has been studied by an archaeometric non-destructive technique. The pottery fragments were accidentally discovered in the Santa Dalmacia farm, sited near Cambé city at the north of Paraná Brazilian state. Each one of these fragments came from different ceramic recipients and their physical characteristics are very similar. The EDXRF measurements were performed employing both an X-ray tube and three radioisotope sources (Fe, Cd and Pu). The compositional data of the ceramics paste and pigments is investigated. For detection of the elements within the ceramic paste, the fragments were irradiated at the center of the lateral section, while several superficial areas with remaining plastic decoration were also chosen and irradiated at the convex and concave sides of each fragment. A paste-subtracted compositional data of the remaining pigments was statically extracted from the XRF analysis of each area. A program based on the graphic polygonal representation method was developed and used to correlate the representative intensity data of each fragment.Um conjunto de fragmentos cerâmicos indígenas brasileiros pertencentes à Tradição Tupi-Guarani foi estudado por uma técnica arqueométrica não destrutiva. Os fragmentos cerâmicos foram descobertos acidentalmente na fazenda Santa Dalmácia, situada próximo da cidade de Cambé, no norte do estado do Paraná. Cada um desses fragmentos veio de diferentes recipientes cerâmicos e suas características físicas são muito similares. As medidas EDXRF foram realizadas empregando tanto um tubo de raios X como três fontes de radioisótopos (55Fe, 109Cd e 238Pu). Os dados de composição da pasta cerâmica e dos pigmentos são investigados. Para detecção dos elementos contidos na pasta cerâmica, os fragmentos foram irradiados no centro da secção lateral, enquanto algumas áreas com decoração plástica remanescente também foram escolhidas e irradiadas nos lados convexo e côncavo de cada fragmento. Foram obtidas as composições dos pigmentos remanescentes em cada área analisada, subtraindo-se do espectro XRF da área considerada o espectro XRF da pasta cerâmica. Um programa baseado no método de representação poligonal gráfica foi desenvolvido e usado para correlacionar a intensidade representativa de cada fragmento