Domain configuration and magnetization switching in arrays of permalloy nanostripes

The proximity effect in the collective behavior of arrays of magnetic nanostripes is currently a subject of intensive research. The imperative of reducing the size and distances between elements in order to achieve higher storage capacity, faster access to the information as well as low energy consumption, brings consequences about the isolated behavior of the elements and devices. Parallel to each other permalloy nanostripes with high aspect ratio have been prepared by the nanolithography technique. The evolution of the closure domains and the magnetization direction in individual nanostructures has been imaged under applied magnetic fields using Variable Field Magnetic Force Microscopy. Moreover, the magnetostatic interactions between neighboring elements and the proximity effects in arrays of such nanostructures have been quantitatively analyzed by Magnetic Force Microscopy and micromagnetic simulations. The agreement between simulations and the experimental results allows us to conclude the relevance of those interactions depending on the geometry characteristics. In particular, results suggest that the magnetostatic coupling between adjacent nanostripes vanishes for separation distances higher than 500 nm

Photon-counting double-random-phase encoding for secure image verification and retrieval

Preprin

Development and validation of the coach's task presentation scale: A quantitative self-report instrument

Objective: A major concern for coaches is the transmission of effective information in the moments before sport practice, when they communicate to players what they are supposed to do and how (Rink, 1994). The present study's main objective was to cover a gap in the sport psychology measurement field and to develop and validate a quantitative self-report instrument to measure the effectiveness of coaches' task presentation for athletes. The resulting instrument was the Escala de Presentacion de las Tareas por Parte del Entrenador (EPTE) [Coach's Task Presentation Scale]. Design: The two studies developed to validate the EPTE used a cross-sectional research design. Method: Participants in Study 1 included 830 college athletes aged between 18 and 27, who completed the EPTE. Participants in Study 2 included 677 college athletes aged between 17 and 29, who completed the EPTE and other questionnaires measuring coach's interpersonal style (autonomy support and controlling style) and basic psychological needs satisfaction/thwarting. Study 1 comprised translation, item formulation and examination of the reliability and factorial structure of the EPTE. Study 2 provided evidence of factorial validity and evidence of validity based on relationships with other variables in the context of the Self Determination Theory (Deci & Ryan, 2000). Results: The results of reliability analysis and the different sources of validity provided, demonstrated the instrument's adequacy in terms of psychometric properties. Conclusions: The EPTE is a valid, reliable scale that can be used to measure the effectiveness of task presentation by coaches, according to the perception of athletes

IAA : Información y actualidad astronómica (46)

Sumario: UPWARDS: ciencia nueva para un planeta viejo.-- La teoría del estado estacionario.-- Sorpresas en la nebulosa del Huevo Podrido.-- DECONSTRUCCIÓN Y otros ENSAYOS. Binarias de rayos X.-- Homenaje a Javier Gorosabel.-- EL “MOBY DICK” DE... Christina Thöne (IAA).-- CIENCIA EN HISTORIAS...Maria Mitchell.-- ACTUALIDAD.-- SALA LIMPIA.-- CIENCIA: PILARES E INCERTIDUMBRES. Mercurio.N

Effects of Multiple Supplementary Cementitious Materials on Workability and Segregation Resistance of Lightweight Aggregate Concrete

In view of the global sustainable development, it is imperative that supplementary cementing materials (SCM) be used for replacing cement in the concrete industry and several researchers have shown that mineral admixtures can enhance the workability of lightweight aggregate concrete (LWAC) mixture and its strength. In view of the beneficial effects of using SCM in LWAC, this article aims to verify the possible influence of the use of different types of SCM in the segregation phenomenon of LWAC. Three different SCM were studied: Silica Fume (SF), Fly Ash (FA) and Posidonia oceanica Ash (PA). For each SCM, three mixtures were prepared, considering three different percentage substitutions of cement. An image analysis technique was applied to estimate the segregation in each sample. The results show that a substitution of cement by other materials with different grain size, considering a constant water binder ratio, may also result in a variation of the consistency of concrete and the viscosity of the mortar matrix, which may contribute to increase or reduce segregation.This research was supported by the University of Alicante (GRE13-03) and (VIGROB-256)

Electrodeposited amorphous CoP multilayers with high permeability

Multilayer films composed of Co_(x)P_(1-x) ferromagnetic layers with different composition (0.74 < x < 0.86) have been obtained by varying the electrolytic current during the deposition process. These samples exhibit planar anisotropy, high permeability and a very low coercive force (similar to 5 A/m). The magnetic properties of these samples have been compared with the properties of Co_(x)P_(1-x) multilayers consisting of magnetic and non-magnetic (x < 0.7) layers

La investigación dirigida como base didáctica de la docencia de la Histología Aplicada: el uso del portafolios

El proceso de adaptación al Espacio Europeo de Educación Superior (EEES) conlleva un nuevo diseño conceptual y metodológico en el proceso de enseñanza/aprendizaje. Dicho proceso supone un cambio de mentalidad para profesorado y alumnado, ya que la educación estará centrada en el aprendizaje, y éste, a su vez, se basará en la adquisición de competencias por parte del estudiante –esto es, el conjunto de habilidades que le capacitan para la realización de una tarea y la consecución de un objetivo.La adquisición de competencias se programa de un modo similar al modelo clásico de la enseñanza, es decir, tanto a través de la asistencia a clase como mediante la realización de actividades académicas dirigidas, si bien: ya no sólo el conocimiento es lo fundamental, ésta es una competencia importante pero una más entre otras muchas; el conocimiento no sólo lo tiene el profesor, pues, de modo general, el alumnado dispone de un rápido y fácil acceso a la información mediante las nuevas tecnologías; la transmisión de conocimiento no debe centrarse en la clase magistral y en los apuntes; y, algo muy importante en nuestra opinión, el alumnado no sólo tiene que estudiar sino que ha de mostrar una actitud activa en el proceso de aprendizaje

Human Papillomavirus (HPV) infection in pregnant women and mother-to-child transmission of genital HPV genotypes: a prospective study in Spain

Background: Studies on HPV infection in pregnant women and HPV transmission to the child have yielded inconsistent results. Methods: To estimate mother-to-child HPV transmission we carried out a prospective cohort study that included 66 HPV-positive and 77 HPV-negative pregnant women and their offspring attending a maternity hospital in Barcelona. To estimate HPV prevalence and genotype distribution in pregnancy we also carried out a related screening survey of cervical HPV-DNA detection among 828 pregnant women. Cervical cells from the mother were collected at pregnancy (mean of 31 weeks) and at the 6-week post-partum visit. Exfoliated cells from the mouth and external genitalia of the infants were collected around birth, at the 6-week post-partum visit, and around 3, 6, 12, and 24 months of age. All samples were tested for HPV using PCR. Associations between potential determinants of HPV infection in pregnant women and of HPV positivity in infants were also explored by logistic regression modelling. Results: Overall cervical HPV-DNA detection in pregnant women recruited in the HPV screening survey was 6.5% (54/828). Sexual behavior-related variables, previous histories of genital warts or sexually transmitted infections, and presence of cytological abnormalities were statistically significantly and positively associated with HPV DNA detection in pregnant women recruited in the cohort. At 418 infant visits and a mean follow-up time of 14 months, 19.7% of infants born to HPV-positive mothers and 16.9% of those born to HPV-negative mothers tested HPV positive at some point during infants' follow-up. The most frequently detected genotype both in infants and mothers was HPV-16, after excluding untyped HPV infections. We found a strong and statistically significant association between mother's and child's HPV status at the 6-week post-partum visit. Thus, children of mothers' who were HPV-positive at the post-partum visit were about 5 times more likely to test HPV-positive than children of corresponding HPV-negative mothers (p = 0.02). Conclusion: This study confirms that the risk of vertical transmission of HPV genotypes is relatively low. HPV persistence in infants is a rare event. These data also indicate that vertical transmission may not be the sole source of HPV infections in infants and provides partial evidence for horizontal mother-to-child HPV transmission