886 research outputs found

    Gobierno y eficiencia de las cajas de ahorro espa¤olas

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    El presente trabajo analiza la relaci¢n existente entre la composici¢n y estructura de los ¢rganos de gobierno de las cajas de ahorros espa¤olas y su eficiencia en el a¤o 1999. Utilizando ecuaciones tobit los resultados del estudio constatan la existencia de una relaci¢n negativa entre la participaci¢n de las administraciones p£blicas en el consejo de administraci¢n de las cajas y su eficiencia en costes calculada, alternativamente, a trav‚s de un modelo de frontera eficiente y de la ratio gastos de explotaci¢n entre margen ordinario. Asimismo se evidencia una relaci¢n positiva entre la participaci¢n de pol¡ticos en el consejo y la canalizaci¢n de mayores recursos financieros hacia obras sociales.Teor¡a de la agencia; gobierno corporativo; consejo de administraci¢n; cajas de ahorros; eficiencia

    Intercellular Diffusion of a Fluorescent Sucrose Analog via the Septal Junctions in a Filamentous Cyanobacterium

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    D.J.N. was supported by a Queen Mary University of London College studentship. M.N.M. was the recipient of an FPU (Formación del Personal Universitario) fellowship from the Spanish Government. Work in Seville was supported by grant BFU2011-22762 from Plan Nacional de Investigación, Spain, cofinanced by the European Regional Development Fund, and by Plan Andaluz de Investigación, Regional Government of Andalucía (grant P10-CVI-6665). Research in Tübingen was supported by the Deutsche Forschungsgemeinschaft (SFB766)

    Gender gap in STEM: a cross-sectional study of primary school students’ self-perception and test anxiety in mathematics

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    Contribution: Significant gender differences are observed on primary school students’ perception of self-efficacy and test anxiety in mathematics. Girls perceive themselves to be significantly worse than boys in mathematics and report higher test anxiety toward mathematics exams. Gender differences in self-efficacy become more pronounced as students grow up, and test anxiety increases for all students. However, the present study shows that teachers’ do not perceive differences in self-efficacy in mathematics between boys and girls. Background: The low presence of women in science, technology, engineering, and mathematics (STEM) might be explained by the attitude of young students toward mathematics. Different studies show that girls are less interested in STEM areas than boys during secondary school. A study on the reasons for this fact pointed out that the early years of education can provide a relevant insight to reverse the situation. Research Questions: Is there any age-dependent gender difference in primary school students in aspects related to mathematics? Are teachers aware of students’ perceptions? Methodology: This work presents a study of over 2000 primary school students (6–12 years old) and 200 teachers in Aragón (Spain). The study consists of a survey on aspects that influence the experience of female and male students with mathematics and Spanish language for comparison purposes and teacher’s awareness of students’ perception. Findings: The present study shows that during primary school, girls are more likely to experiment a negative attitude toward mathematics than boys as they grow up, and teachers may not perceive girls’ situation. La baja presencia de mujeres en ciencia, tecnología, la ingeniería y las matemáticas (STEM) podrían explicarse por la actitud de las niños y niñas hacia las matemáticas. Diferentes estudios muestran que las niñas están menos interesadas en las áreas STEM que niños cuando cursan educación secundaria. Además, un estudio sobre los motivos para este hecho señaló que los primeros años de educación podrían proporcionar una visión relevante para revertir la situación. Por ello, este trabajo parte de las siguientes preguntas de investigación, ¿Existe alguna diferencia de género que sea dependiente de la edad en estudiantes de educación primaria en aspectos relacionados con las matemáticas? ¿Conoce el profesorado la autopercepción de sus estudiantes? Las principales contribuciones de este trabajo son que las diferencias significativas de género se observan en la percepción de autoeficacia de los estudiantes de primaria y ansiedad ante los exámenes en matemáticas. Las niñas se perciben a sí mismas significativamente peor que los niños en matemáticas e indican mayor ansiedad ante los exámenes de matemáticas. Las diferencias de género en la autoeficacia se vuelven más pronunciada a medida que los estudiantes crecen, mientras que la ansiedad ante los exámenes aumenta para todos los estudiantes. Pese a estos resultados, el presente estudio muestra que los profesores no perciben diferencias en la autoeficacia en matemáticas entre niños y niñas. Este estudio se basa en las encuestas realizadas a más de 2000 escolares (6-12 años) y 200 profesores en Aragón (España). El estudio consiste en una encuesta a los estudiantes sobre aspectos que pueden influir en la experiencia de los niños y niñas con las matemáticas, así como con la lengua española para disponer de una materia que permita establecer comparaciones y una encuesta al profesor que incluye cuestiones sobre su percepción de los estudiantes. El principal hallazgo del estudio es que, durante la escuela primaria, es más probable que las niñas experimenten una actitud negativa hacia matemáticas que los niños a medida que crecen, y que los maestros pueden no ser conscientes de la situación de las niñas

    Effect of surface roughness and sterilization on bacterial adherence to ultra-high molecular weight polyethylene

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    AbstractSterilization with ethylene oxide (EO) and gas plasma (GP) are well-known methods applied to ultra-high molecular weight polyethylene (UHMWPE) surfaces in the belief that they prevent major material changes caused by gamma irradiation. However, the influence of these surface sterilization methods on bacterial adherence to UHMWPE is unknown. UHMWPE samples with various degrees of roughness (0.3, 0.8 and 2.0 µm) were sterilized with either GP or EO. The variations in hydrophobicity, surface free energy and surface functional groups were investigated before and after sterilization. Sterilized samples were incubated with either Staphylococcus aureus or Staphylococcus epidermidis in order to study bacterial adherence to these materials. Fewer bacteria adhered to UHMWPE after sterilization with EO than after sterilization with GP, especially to the smoothest surfaces. No changes in chemical composition of the UHMWPE surface due to sterilization were observed using X-ray photoemission spectroscopy analysis. The decreased bacterial adherence to UHMWPE found at the smoothest surfaces after sterilization with EO was not directly related to changes in chemical composition. Increased bacterial adherence to rougher surfaces was associated with increased polar surface energy of EO-sterilized surfaces

    Changing Dose of Progesterone Results in Sudden Changes in Frequency of Luteinizing Hormone Pulses and Secretion of 17β-Estradiol in Bovine Females

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    The aim of the present study was to elucidate the time course according to which changes in circulating concentrations of progesterone influence pulsatile secretion of LH and secretion of 17β-estradiol. Our working hypothesis was that changing the dose of progesterone would result in changes in frequency of LH pulses and secretion of 17β-estradiol within 72 h. Five days after behavioral estrus, thirty-three cows were randomly assigned to one of five groups: 1) control, no treatment (CONT, n = 5); 2) treatment with two progesterone-releasing intravaginal devices (PRIDs) for 11 days (2PRID, 5-6 ng/ml plasma progesterone, n = 7); 3) treatment with a 0.5 PRID for 11 days (0.5PRID, 1-2 ng/ml plasma progesterone, n = 7); 4) treatment with 2 PRIDs for 8 days followed by treatment with a 0.5 PRID for 3 days (2-0.5PRID, n = 7); and 5) treatment with a 0.5 PRID for 8 days followed by treatment with 2 PRIDs for 3 days (0.5-2PRID, n = 7). Cows subject to PRID treatments received injections of prostaglandin F2 on Days 1 and 2 (Day 0 = day of initiation of PRID treatments, fifth day of the estrous cycle in CONT cows) to lyse the existing corpus luteum. Cows were bled for 12 h at 15-min intervals on Day 7.5 of the treatment period (twelfth day of the estrous cycle in CONT cows). The dose of progesterone was changed on Day 8 in cows that were assigned to the 2-0.5PRID and 0.5-2PRID groups, and blood collections continued an additional 72 h to characterize profiles of circulating concentrations of LH and 17β-estradiol. Cows treated with a 0.5 PRID had a greater (p \u3c 0.05) number of LH pulses and higher (p \u3c 0.05) concentrations of 17β-estradiol throughout the entire blood collection period than cows in the 2PRID and CONT groups. An increase in the number of LH pulses was detected within 6 h after the change from the high to the low dose of progesterone (2-0.5PRID), and frequency of LH pulses was similar to that of cows in the 0.5PRID group for the remainder of the period of blood collection. LH pulse frequency declined within 6 h after the shift from the low to the high dose of progesterone (0.5-2PRID) and was similar to that of cows in the 2PRID group by 12 h after the dose was changed. Within 6 h after the dose of progesterone was changed, circulating concentrations of 17p-estradiol increased (p \u3c 0.05) in cows shifted from the high to low dose (2-0.5PRID) and declined (p \u3c 0.05) after the dose of progesterone was changed from low to high (0.5-2PRID). We conclude that changing the circulating concentrations of progesterone concurrently affects frequency of pulsatile LH release and secretion of 17β-estradiol within 6-24 h

    Changing Dose of Progesterone Results in Sudden Changes in Frequency of Luteinizing Hormone Pulses and Secretion of 17β-Estradiol in Bovine Females

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    The aim of the present study was to elucidate the time course according to which changes in circulating concentrations of progesterone influence pulsatile secretion of LH and secretion of 17β-estradiol. Our working hypothesis was that changing the dose of progesterone would result in changes in frequency of LH pulses and secretion of 17β-estradiol within 72 h. Five days after behavioral estrus, thirty-three cows were randomly assigned to one of five groups: 1) control, no treatment (CONT, n = 5); 2) treatment with two progesterone-releasing intravaginal devices (PRIDs) for 11 days (2PRID, 5-6 ng/ml plasma progesterone, n = 7); 3) treatment with a 0.5 PRID for 11 days (0.5PRID, 1-2 ng/ml plasma progesterone, n = 7); 4) treatment with 2 PRIDs for 8 days followed by treatment with a 0.5 PRID for 3 days (2-0.5PRID, n = 7); and 5) treatment with a 0.5 PRID for 8 days followed by treatment with 2 PRIDs for 3 days (0.5-2PRID, n = 7). Cows subject to PRID treatments received injections of prostaglandin F2 on Days 1 and 2 (Day 0 = day of initiation of PRID treatments, fifth day of the estrous cycle in CONT cows) to lyse the existing corpus luteum. Cows were bled for 12 h at 15-min intervals on Day 7.5 of the treatment period (twelfth day of the estrous cycle in CONT cows). The dose of progesterone was changed on Day 8 in cows that were assigned to the 2-0.5PRID and 0.5-2PRID groups, and blood collections continued an additional 72 h to characterize profiles of circulating concentrations of LH and 17β-estradiol. Cows treated with a 0.5 PRID had a greater (p \u3c 0.05) number of LH pulses and higher (p \u3c 0.05) concentrations of 17β-estradiol throughout the entire blood collection period than cows in the 2PRID and CONT groups. An increase in the number of LH pulses was detected within 6 h after the change from the high to the low dose of progesterone (2-0.5PRID), and frequency of LH pulses was similar to that of cows in the 0.5PRID group for the remainder of the period of blood collection. LH pulse frequency declined within 6 h after the shift from the low to the high dose of progesterone (0.5-2PRID) and was similar to that of cows in the 2PRID group by 12 h after the dose was changed. Within 6 h after the dose of progesterone was changed, circulating concentrations of 17p-estradiol increased (p \u3c 0.05) in cows shifted from the high to low dose (2-0.5PRID) and declined (p \u3c 0.05) after the dose of progesterone was changed from low to high (0.5-2PRID). We conclude that changing the circulating concentrations of progesterone concurrently affects frequency of pulsatile LH release and secretion of 17β-estradiol within 6-24 h

    Child Protective Services Guidelines for Substantiating Exposure to Domestic Violence as Maltreatment and Assigning Caregiver Responsibility: Policy Analysis and Recommendations

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    The purpose of this study was to examine the range of policy approaches used by child welfare systems in the United States to guide workers in classifying and substantiating child exposure to domestic violence (CEDV) as an actionable form of maltreatment. To that end, we conducted a qualitative document analysis of child protective services (CPS) policy manuals from all state-administered child welfare systems in the U.S. ( N = 41). Our findings indicate that a majority of state-administered systems (71%) have adopted policy requiring workers to demonstrate that children have endured harm or the threat of harm before substantiating CEDV-related maltreatment. Many state systems (51%) also include policy directives that require workers to identify a primary aggressor during CPS investigations involving CEDV, while far fewer (37%) provide language that potentially exonerates survivors of domestic violence from being held accountable for failure to protect on the basis of their own victimization. Based on our findings and identification of policy exemplars, we offer a recommended set of quality policy indicators for states to consider in the formulation of their policy guidelines for substantiating children’s exposure to domestic violence that promotes the safety and wellbeing of both children and adult survivors of domestic violence

    Melengestrol Acetate at Greater Doses Than Typically Used for Estrous Synchrony in Bovine Females Does Not Mimic Endogenous Progesterone in Regulation of Secretion of Luteinizing Hormone and 17β-Estradiol

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    Our working hypothesis was that doses of melengestrol acetate (MGA) greater than those typically administered in estrous synchrony regimens would regulate secretion of LH and 17β-estradiol (E2) as endogenous progesterone (P4) does during the midluteal phase of the estrous cycle. We also hypothesized that endogenous P4 from the CL would interact with MGA to further decrease the frequency of LH pulses and E2. Cows on Day 5 of their estrous cycle (Day 0 = estrus) were randomly assigned to an untreated control group (CONT, n = 5) or to one of six MGA treatment groups (n = 5 per group): 1) MGA administered orally each day via a gelatin capsule at a dose of 0.5 mg MGA/cow with the CL present (0.5CL); 2) 0.5 mg MGA/cow daily in the absence of CL (0.5NO); 3) 1.0 mg MGA with CL present (1.OCL); 4) 1.0 mg MGA without CL (1.ONO); 5) 1.5 mg MGA with CL present (1.5CL); 6) 1.5 mg without CL (1.5NO). MGA was administered for 10 days (Day 5 = initiation of treatment). To regress CL, cows assigned to groups without CL received injections of prostaglandin F2α (PGF, 0; 25 mg) on Days 6 and 7 of their estrous cycle. All cows were administered PGF2α. at the end of the 10-day treatment period. During the treatment period, daily blood samples were collected to determine concentrations of E2. Serial blood samples were collected at 15-min intervals for 24 h on Days 8, 11, and 14 to determine pattern of LH secretion. Frequency of LH pulses on Days 8, 11, and 14 was greater (p \u3c 0.05) in cows without CL (0.5NO, 1.ONO, and 1.5NO) than in cows with CL (0.5CL, 1.OCL, 1.5CL, and CONT). Mean concentrations of LH were greater (p \u3c 0.05) in cows from the 0.5NO group on Days 8 and 11 and were greater (p \u3c 0.05) in cows from the 0.5NO, 1.ONO, and 1.5NO groups on Day 14 as compared to cows with CL. Overall mean concentrations of LH across Days 8, 11, and 14 were greatest (p \u3c 0.05) in cows from the 0.5NO group and were also greater (p \u3c 0.05) in cows from the 0.5NO, 1.ONO, and 1.5NO groups as compared to cows in the 0.5CL, 1.OCL, 1.5CL, and CONT groups. Mean concentrations of E2 during the treatment period were greater (p \u3c 0.05) in cows from the 0.5NO group than in cows from either the 1.ONO or the 1.5NO group; these values were also greater (p \u3c 0.05) in cows of the 0.5NO, 1.ONO, and 1.5NO groups as compared to cows of the 1.OCL and CONT groups. Therefore, we reject our working hypothesis because doses of MGA greater than those typically used in estrous synchrony protocols did not suppress LH and E2 to the same extent that endogenous P4 does. In addition, MGA treatment when CL were present did not result in a further suppression of LH pulse frequency or of E2 as compared to the values in control cows with functional CL
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