263 research outputs found

    Zero Jordan product determined Banach algebras

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    A Banach algebra AA is said to be a zero Jordan product determined Banach algebra if every continuous bilinear map φ ⁣:A×AX\varphi\colon A\times A\to X, where XX is an arbitrary Banach space, which satisfies φ(a,b)=0\varphi(a,b)=0 whenever aa, bAb\in A are such that ab+ba=0ab+ba=0, is of the form φ(a,b)=σ(ab+ba)\varphi(a,b)=\sigma(ab+ba) for some continuous linear map σ\sigma. We show that all CC^*-algebras and all group algebras L1(G)L^1(G) of amenable locally compact groups have this property, and also discuss some applications

    Psychometric Characteristics of the Physical Activity Enjoyment Scale in the Context of Physical Activity in Nature

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    The aim of this study was to analyze the psychometric properties of the Physical Activity Enjoyment Scale applied to different contexts for initial or original use, such as in the context of physical activity in nature. In order to do this, we carried out a study at some primary and secondary schools located in western Andalucía (Spain), with students aged 9–12 years old (M = 11.22; SD = 1.07). Therefore, a sample of 206 students in Study 1 (98 boys = 47.8%; 107 girls = 52.2%) and 455 students in Study 2 (228 boys = 50.1% 227 girls = 49.9%) was used. The students of the two groups that belong to the study created a program related to Physical Activity in Nature. Descriptive, exploratory, and confirmatory analyses were conducted. We also analyzed several other factors, such as internal consistency, composite reliability, average extracted variance, and convergent validity. Afterward, di erences according to gender and school year were also studied. The data showed the need to eliminate many of the items from the original scale, giving, as a result, a model of six items that satisfactorily fit into the confirmatory analysis for the use of physical activity in nature. The ANOVA statistical test, used to analyze sex and school year, did not show any tangible differences between the target groups. Thanks to its application, we note that the PACES instrument cannot be applied as-is; some items must be removed or modified. Therefore, we must obtain a new, more specific instrument for these types of incipient practices undertaken in natural environments

    Application of learning and knowledge technologies (LKT) in the teaching of physical and sports activities in the natural environment in Physical Education lessons

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    Resumen basado en el de la publicaciónTítulo, resumen y palabras clave también en inglésLa finalidad tanto de la webquest como de la página web es guiar al alumno en la búsqueda e investigación de una tarea propuesta, facilitándole a su vez las herramientas necesarias, con el objetivo de que adquiera las competencias marcadas. Por ello, se describe la aplicación práctica de ambas herramientas en las clases de Educación Física de la Educación Secundaria Obligatoria, con contenidos relacionados con las actividades físico-deportivas en el medio natural. Así, se pretende aportar ideas adicionales que motiven al uso de las tecnologías de la información y de la comunicación como herramienta didáctica dentro del ámbito de la Educación Física.ES

    The Kadison problem on a class of commutative Banach algebras with closed cone

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    summary:The main result of the paper characterizes continuous local derivations on a class of commutative Banach algebra AA that all of its squares are positive and satisfying the following property: Every continuous bilinear map Φ\Phi from A×AA\times A into an arbitrary Banach space BB such that Φ(a,b)=0\Phi(a,b)=0 whenever ab=0ab=0, satisfies the condition Φ(ab,c)=Φ(a,bc)\Phi (ab,c)=\Phi(a,bc) for all a,b,cAa,b,c\in A

    Goal orientations, satisfaction, beliefs in sport success and motivational climate in swimmers.

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    En el presente estudio se plantearon varios objetivos; comprobar las relaciones existentes entre las orientaciones de meta, la satisfacción, las creencias sobre las causas del éxito en el deporte y el clima motivacional percibido en nadadores; examinar el efecto que tiene la orientación de meta en las diferentes dimensiones analizadas; y, por último, predecir la orientación de meta. La muestra estuvo compuesta por 163 nadadores. Los instrumentos utilizados fueron las versiones validadas al castellano del TEOSQ, SSI, BACSSQ y PMCSQ-2. Se realizaron tres tipos de análisis estadísticos: análisis de correlaciones bivariadas, análisis multivariante (MANOVA 2x2) y análisis de regresión lineal múltiple multivariado por pasos. Los resultados mostraron que la capacidad y el aburrimiento son variables predictoras de la orientación de meta hacia el ego, mientras que el esfuerzo y la diversión lo son de las orientaciones de meta hacia la tareaThe present study had several objectives; to check the relationships between goal orientations, satisfaction, beliefs about the causes of success in sport and motivational climate perceived in swimmers; to examine the effect of goal orientation in different dimensions analyzed, and finally to predict goal orientation. The sample consisted of 163 swimmers. The instruments used were validated to Castilian versions of TEOSQ, SSI, BACSSQ and PMCSQ-2. There were three types of statistical analyzes: bivariate correlation analysis, multivariate analysis (MANOVA 2x2) and multiple linear regression analysis stepwise multivariate. The results showed that capacity and boredom are predictors of goal orientation towards the ego, while effort and fun are the goal orientations to the tas

    Natural course of septo-optic dysplasia: Retrospective analysis of 20 cases

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    Introducción. La displasia septoóptica (DSO) es la combinación variable de signos de disgenesia de línea media cerebral, hipoplasia de nervios ópticos y disfunción hipotálamo-hipofisaria, asociándose, a veces, con un espectro variado de malformaciones de la corteza cerebral. Objetivo. Describir la evolución natural y los hallazgos de neuroimagen en una serie de 20 pacientes diagnosticados. Pacientes y métodos. Se revisan de forma retrospectiva las características epidemiológicas, clínicas y neurroradiológicas de 20 pacientes consecutivos diagnosticados de DSO entre enero de 1985 y enero de 2010. Se analizaron los datos de tomografía computarizada, resonancia magnética craneal, electroencefalograma, potenciales evocados visuales, valoración oftalmológica, cariotipo y estudio endocrinológico. En siete pacientes, se realizó estudio del gen Homeobox HESX1. Resultados. El 60% de los casos presentaba antecedentes patológicos en el primer trimestre de gestación, con las ecografías fetales normales. Clínicamente, destacaban manifestaciones visuales (85%), alteraciones endocrinas (50%), retraso mental (60%) y crisis epilépticas (55%). Un 55% se asociaba a anomalías de migración neuronal. En un 45%, la DSO era el único hallazgo de neuroimagen. Se realizó cariotipo a todos, siendo normal. El gen HESX1 fue positivo en dos de los siete casos estudiados (ambos con DSO aislada). Ninguno con mutación en el gen HESX1 presentaba consanguinidad familiar. No se realizó estudio genético a los padres. Conclusiones. La DSO debe clasificarse como un síndrome malformativo heterogéneo, que asocia múltiples anomalías cerebrales, oculares, endocrinas y sistémicas. Las formas más graves se asocian con anomalías de la migración neuronal y de la organización cortical (AU)Introduction. Septo-optic dysplasia (SOD) is the variable combination of signs of dysgenesis of the midline of the brain, hypoplasia of the optic nerves and hypothalamus-pituitary dysfunction, which is sometimes associated with a varied spectrum of malformations of the cerebral cortex. Aims. To describe the natural history and neuroimaging findings in a series of 20 diagnosed patients. Patients and methods. We review the epidemiological, clinical and neuroimaging characteristics of 20 consecutive patients diagnosed with SOD between January 1985 and January 2010. Data obtained from computerised tomography, magnetic resonance imaging of the head, electroencephalogram, visual evoked potentials, ophthalmological evaluation, karyotyping and endocrinological studies were analysed. In seven patients, a study of the gene Homeobox HESX1 was conducted. Results. Pathological antecedents in the first three months of gestation were presented by 60% of the cases, with normal results in the foetal ultrasound scans. Clinically, the most striking features were visual manifestations (85%), endocrine disorders (50%), mental retardation (60%) and epileptic seizures (55%). Fifty-five per cent were associated to abnormal neuronal migration. In 45%, SOD was the only finding in the neuroimaging scans. Karyotyping was performed in all cases, the results being normal. Gene HESX1 was positive in two of the seven cases studied (both with isolated SOD). None of those with mutation in gene HESX1 presented familial consanguinity. No gene study was conducted with the parents. Conclusions. SOD must be classified as a heterogeneous malformation syndrome, which is associated to multiple brain, ocular, endocrine and systemic anomalies. The most severe forms are associated with abnormal neuronal migration and cortical organisation (AU
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