4,250 research outputs found

    Assessing math anxiety in elementary schoolchildren through a Spanish version of the Scale for Early Mathematics Anxiety (SEMA)

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    Math anxiety (MA) affects students of all age groups. Because of its effects on children’s academic development, the need to recognize its early manifestations has been highlighted. We designed a European-Spanish version of the Scale for Early Mathematics Anxiety (SEMA; Wu et al. (2012)), and assessed its psychometric properties in a sample of children aged 7 to 12 years. The participants (967 typically developing children) were elementary school students recruited from ten schools. Children reported their general and math anxiety levels in an individual session and performed nonverbal IQ and math abilities subtests in a group session. Teachers reported the final math grades. The psychometric indices obtained, and the resulting factor structure revealed that the European-Spanish version of the SEMA developed in this study is a reliable and valid measure to evaluate MA in children from 3rd to 6th grade. Moreover, we explored gender differences, that resulted in small effect sizes, which disappeared when controlling for trait anxiety. Differences across grades were found for both global MA and the numerical processing anxiety factor but not for the situational and performance anxiety factor. Finally, MA was negatively associated with students’ math achievement, although the strength of the associations varied with the MA measure selected, the kind of math achievement analyzed, and the school stage considered. Our findings highlight the relevance of MA in elementary school and highlight the need for an early identification of students at risk of suffering MA to palliate the negative consequences of MA in children’s cognitive and academic development

    Effortful control is associated with children's school functioning via learning-related behaviors

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    The goal of the current study was to identify factors that contribute to individual differences in school functioning. We proposed a model including direct effects of Effortful Control (EC) on Spanish 6- to 12-year olds' (N = 142) academic achievement and social adaptation at school, with these relations partially mediated by learning-related behaviors (LRBs). Parents rated children's EC; teachers reported children's LRBs and children' social adaptation in school; children' social preference was assessed through classmates' nominations. Children's academic achievement was measured through standard tests and grades. Analyses were run using structural equation models, controlling by gender, intelligence, age, socioeconomic status, and school. EC was positively and directly related to social adaptation in school. EC was also indirectly related to academic achievement and social adaptation through LRBs. The findings highlight the potential relevance of children's EC and LRBs for adjustment in elementary school

    The cosmic evolution of the spatially-resolved star formation rate and stellar mass of the CALIFA survey

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    We investigate the cosmic evolution of the absolute and specific star formation rate (SFR, sSFR) of galaxies as derived from a spatially-resolved study of the stellar populations in a set of 366 nearby galaxies from the CALIFA survey. The analysis combines GALEX and SDSS images with the 4000 break, H_beta, and [MgFe] indices measured from the datacubes, to constrain parametric models for the SFH, which are then used to study the cosmic evolution of the star formation rate density (SFRD), the sSFR, the main sequence of star formation (MSSF), and the stellar mass density (SMD). A delayed-tau model, provides the best results, in good agreement with those obtained from cosmological surveys. Our main results from this model are: a) The time since the onset of the star formation is larger in the inner regions than in the outer ones, while tau is similar or smaller in the inner than in the outer regions. b) The sSFR declines rapidly as the Universe evolves, and faster for early than for late type galaxies, and for the inner than for the outer regions of galaxies. c) SFRD and SMD agree well with results from cosmological surveys. At z< 0.5, most star formation takes place in the outer regions of late spiral galaxies, while at z>2 the inner regions of the progenitors of the current E and S0 are the major contributors to SFRD. d) The inner regions of galaxies are the major contributor to SMD at z> 0.5, growing their mass faster than the outer regions, with a lookback time at 50% SMD of 9 and 6 Gyr for the inner and outer regions. e) The MSSF follows a power-law at high redshift, with the slope evolving with time, but always being sub-linear. f) In agreement with galaxy surveys at different redshifts, the average SFH of CALIFA galaxies indicates that galaxies grow their mass mainly in a mode that is well represented by a delayed-tau model, with the peak at z~2 and an e-folding time of 3.9 Gyr.Comment: 23 pages, 16 figures, 6 tables, accepted for publication in Astronomy & Astrophysics. *Abridged abstract

    SLUG in cancer development

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    The SNAIL-related zinc-finger transcription factor, SLUG (SNAI2), is critical for the normal development of neural crest-derived cells and loss-of-function SLUG mutations have been proven to contribute to piebaldism and Waardenburg syndrome type 2 in a dose-dependent fashion. While aberrant induction of SLUG has been documented in cancer cells, relatively little is known about the consequences of SLUG overexpression in malignancy. To investigate the potential role of SLUG overexpression in development and in cancer, we generated mice carrying a tetracycline-repressible Slug transgene. These mice were morphologically normal at birth, and developed mesenchymal tumours (leukaemia and sarcomas) in almost all cases examined. Suppression of the Slug transgene did not rescue the malignant phenotype. Furthermore, the BCR–ABL oncogene, which induces Slug expression in leukaemic cells, did not induce leukaemia in Slug-deficient mice, implicating Slug in BCR–ABL leukaemogenesis in vivo. Overall, the findings indicate that while Slug overexpression is not sufficient to cause overt morphogenetic defects in mice, they demonstrate a specific and critical role for Slug in the pathogenesis of mesenchymal tumours.Research in our group is supported by MEyC (BIO2000-0453-P4-02, SAF2003- 01103and FIT-010000-2004-157), Junta de Castilla y León (CSI06/03), ADE de Castilla y León (04/04/SA/0001), FIS (PI020138, G03/179, and G03/136) and USALCIBASA project. MPC is a recipient of an MCyT fellowship and MSM is supported by Fundación Cientíica de la AECC.Peer reviewe

    A forced thermal ratchet in a memory heat bath

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    The present work studies a non-Markovian forced thermal ratchet model on an asymmetric periodic potential. The Brownian dynamics is described by a generalized Langevin equation with an Ornstein-Uhlenbeck-type friction memory kernel. We show that for the case of a time-dependent driving force, also in the form of an Ornstein-Uhlenbeck-like process, an exact expression of the probability current can be derived. We also obtain the behavior of the particle's average rate of flow as a function of the external amplitude force and of the bath temperature when the driving force behaves as a square wave modulation. All our results are compared with those obtained in the Markovian case and we find, fairly remarkably, that in some cases a friction memory kernel results in an enhancement of the curren

    Non-ergodic effects in the Coulomb glass: specific heat

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    We present a numerical method for the investigation of non-ergodic effects in the Coulomb glass. For that, an almost complete set of low-energy many-particle states is obtained by a new algorithm. The dynamics of the sample is mapped to the graph formed by the relevant transitions between these states, that means by transitions with rates larger than the inverse of the duration of the measurement. The formation of isolated clusters in the graph indicates non-ergodicity. We analyze the connectivity of this graph in dependence on temperature, duration of measurement, degree of disorder, and dimensionality, studying how non-ergodicity is reflected in the specific heat.Comment: Submited Phys. Rev.

    Influence of climate change on the flowering of temperate fruit trees

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    It is well known that winter chilling is necessary for the flowering of temperate trees. The chilling requirement is a criterion for choosing a species or variety at a given location. Also chemistry products can be used for reducing the chilling-hours needs but make our production more expensive. This study first analysed the observed values of chilling hours for some representative agricultural locations in Spain for the last three decades and their projected changes under climate change scenarios. Usually the chilling is measured and calculated as chilling-hours, and different methods have been used to calculate them (e.g. Richarson et al., 1974 among others) according to the species considered. For our objective North Carolina method (Shaltout and Unrath, 1983) was applied for apples, Utah method (Richardson et al. 1974) for peach and grapevine and the approach used by De Melo-Abreu et al. (2004) for olive trees. The influence of climate change in temperate trees was studied by calculating projections of chilling-hours with climate data from Regional Climate Models (RCMs) at high resolution (25 km) from the European Project ENSEMBLES (http://www.ensembles-eu.org/). These projections will allow for analysing the modelled variations of chill-hours between 2nd half of 20C and 1st half of 21C at the study locations

    Clinical factors associated with discontinuation of ts/bDMARDs in rheumatic patients from the BIOBADASER III registry

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    Altres ajuts: Spanish Agency of Medicines and Medical Devices (AEMPS); Biogen; Bristol Myers-Squibb (BMS); Celltrion Healthcare; Lilly; Merck; Novartis; Pfizer; Regeneron Pharmaceuticals; Samsung Bioepis.Biologic and targeted synthetic disease-modifying antirheumatic drugs (ts/bDMARDs) play a pivotal role in the treatment of rheumatoid arthritis (RA), psoriatic arthritis (PsA), and ankylosing spondylitis (AS). Persistence of therapy provides an index of a drug's overall effectiveness. The objective of the study was to identify factors associated with discontinuation of ts/bDMARDs in a real-world dataset. The study population comprised patients diagnosed with RA, PsA, and AS included in the BIOBADASER registry for whom follow-up data were available until November 2019. Patient features and treatment data were included in the analysis. The Kaplan-Meier method was used to study survival of the different drugs according to the reason for discontinuation. Factors associated with discontinuation were studied using Cox regression models and bivariate and multivariate analyses. P values of less than 0.05 were regarded as statistically significant. The study population comprised 4,752 patients who received a total of 8,377 drugs, of which 4,411 (52.65%) were discontinued. The Kaplan-Meier curves showed that survival for first-line treatment was greater in all 3 groups (p < 0.001). Patients with RA had a greater risk of discontinuation if they were younger (HR, 0.99; 95% CI 0.99-1.00), if they were receiving anti-TNFα agents (HR, 0.61; 95% CI 0.54-0.70), and if they had more comorbid conditions (HR, 1.09; 95% CI 1.00-1.17). Patients with PsA had a higher risk if they were women (HR, 1.36; 95% CI 1.15-1.62) and if they were receiving other ts/bDMARDs (HR, 1.29; 95% CI 1.05-1.59). In patients with AS, risk increased with age (HR, 1.01; 95% CI 1.00-1.02), as did the number of comorbid conditions (HR, 1.27; 95% CI 1.12-1.45). The factors that most affected discontinuation of ts/bDMARDs were line of treatment, age, type of drug, sex, comorbidity and the year of initiation of treatment. The association with these factors differed with each disease, except for first-line treatment, which was associated with a lower risk of discontinuation in all 3 diseases

    Hablando con el "Gallo" de la pasiĂłn : informaciones cĂłmicas

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    Copia digital. Valladolid : Junta de Castilla y LeĂłn. ConsejerĂ­a de Cultura y Turismo, 2011Precede al tĂ­t.: "El Coco" Reporte

    Dielectric susceptibility of the Coulomb-glass

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    We derive a microscopic expression for the dielectric susceptibility χ\chi of a Coulomb glass, which corresponds to the definition used in classical electrodynamics, the derivative of the polarization with respect to the electric field. The fluctuation-dissipation theorem tells us that χ\chi is a function of the thermal fluctuations of the dipole moment of the system. We calculate χ\chi numerically for three-dimensional Coulomb glasses as a function of temperature and frequency
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