Polarization angle swings in blazars: the case of 3C 279

Kiehlmann, S. et. al.Context. Over the past few years, on several occasions, large, continuous rotations of the electric vector position angle (EVPA) of linearly polarized optical emission from blazars have been reported. These events are often coincident with high energy gamma-ray flares and they have attracted considerable attention, since they could allow us to probe the magnetic field structure in the gamma-ray emitting region of the jet. The flat-spectrum radio quasar 3C 279 is one of the most prominent examples showing this behaviour. Aims. Our goal is to study the observed EVPA rotations and to distinguish between a stochastic and a deterministic origin of the polarization variability. Methods. We have combined multiple data sets of R-band photometry and optical polarimetry measurements of 3C 279, yielding exceptionally well-sampled flux density and polarization curves that cover a period of 2008-2012. Several large EVPA rotations are identified in the data. We introduce a quantitative measure for the EVPA curve smoothness, which is then used to test a set of simple random walk polarization variability models against the data. Results. 3C 279 shows different polarization variation characteristics during an optical low-flux state and a flaring state. The polarization variation during the flaring state, especially the smooth similar to 360 degrees rotation of the EVPA in mid-2011, is not consistent with the tested stochastic processes. Conclusions. We conclude that, during the two different optical flux states, two different processes govern polarization variation, which is possibly a stochastic process during the low-brightness state and a deterministic process during the flaring activity.S.K. was supported for this research through a stipend from the International Max Planck Research School (IMPRS) for Astronomy and Astrophysics at the Max Planck Institute for Radio Astronomy in cooperation with the Universities of Bonn and Cologne. T.S. was partly supported by the Academy of Finland project 274477. The research at Boston University was partly funded by NASA Fermi GI grant NNX11AQ03G. K.V.S. is partly supported by the Russian Foundation for Basic Research grants 13-02-12103 and 14-02-31789. N.G.B. was supported by the RFBR grant 12-02-01237a. E.B., M.S. and D.H. thank financial support from UNAM DGAPA-PAPIIT through grant IN116211-3. I. A. acknowledges support by a Ramon y Cajal grant of the Spanish Ministry of Economy and Competitiveness (MINECO). The research at the IAA-CSIC and the MAPCAT program are supported by the Spanish Ministry of Economy and Competitiveness and the Regional Government of Andalucia (Spain) through grants AYA2010-14844, AYA2013-40825-P, and P09-FQM-4784. The Calar Alto Observatory is jointly operated by the Max-Planck-Institut fur Astronomie and the Instituto de Astrofisica de Andalucia-CSIC. Data from the Steward Observatory spectropolarimetric monitoring project were used. This program is supported by Fermi Guest Investigator grants NNX08AW56G, NNX09AU10G, NNX12AO93G, and NNX14AQ58G. St. Petersburg University team acknowledges support from Russian RFBR grant 15-02-00949 and St. Petersburg University research grant 6.38.335.2015. The Abastumani team acknowledges financial support of the project FR/638/6-320/12 by the Shota Rustaveli National Science Foundation under contract 31/77.Peer reviewe

Estilo cognitivo dependencia-independencia de campo: un análisis del funcionamiento atencional

Previous research has indicated that field-dependent children display poorer performance than field-independent children in almost all academic subjects and cognitive tasks. However, the processes underlying this poorer performance remain unclear. The present study aimed to assess whether children with different FDI cognitive styles show differences in performance of tasks measuring aspects of attentional functioning. Specifically, 149 children aged 8 - 11 years were classified according to FDI cognitive style (field-dependent, intermediate, or field-independent), and to storage capacity (Digits Forward Test), verbal working memory (Digits Backward Test), capacity to focus, shift, and maintain attention (Digit Symbol Test), and capacity for sustained attention (Visual Search and Attention Test). Field-independent children displayed better performance than intermediate and field-dependent children on all tests except the Digits Forward Test. Theoretical and practical implications of these results are discussedInvestigaciones previas han indicado que los niños dependientes de campo obtienen peores rendimientos que los independientes de campo en casi todas las asignaturas escolares y en diferentes tareas cognitivas. Sin embargo, los procesos que subyacen a este peor rendimiento no están lo suficientemente delimitados. El objetivo de este artículo es analizar si niños con diferentes estilos cognitivos manifiestan diferencias en tareas que miden aspectos concretos del funcionamiento atencional. Específicamente, se explora el rendimiento de 149 niños entre 8 y 11 años en cuatro tareas que evalúan, capacidad de almacenamiento (Dígitos en orden directo), memoria de trabajo verbal (Dígitos en orden inverso), capacidad para dirigir, cambiar y mantener la atención (Claves) y atención sostenida (Test de atención y búsqueda visual). Los resultados indican que los niños independientes de campo mostraron un mejor rendimiento que los dependientes de campo y los del grupo intermedio en todas las tareas a excepción de la prueba de Dígitos en orden directo. Se discuten algunas implicaciones para la teoría y la prácticaS

Exceptional outburst of the blazar CTA 102 in 2012: the GASP-WEBT campaign and its extension

Larionov, V. M. et. al.After several years of quiescence, the blazar CTA 102 underwent an exceptional outburst in 2012 September-October. The flare was tracked from gamma-ray to near-infrared (NIR) frequencies, including Fermi and Swift data as well as photometric and polarimetric data from several observatories. An intensive Glast-Agile support programme of the Whole Earth Blazar Telescope (GASP-WEBT) collaboration campaign in optical and NIR bands, with an addition of previously unpublished archival data and extension through fall 2015, allows comparison of this outburst with the previous activity period of this blazar in 2004-2005. We find remarkable similarity between the optical and gamma-ray behaviour of CTA 102 during the outburst, with a time lag between the two light curves of approximate to 1 h, indicative of cospatiality of the optical and gamma-ray emission regions. The relation between the gamma-ray and optical fluxes is consistent with the synchrotron self-Compton (SSC) mechanism, with a quadratic dependence of the SSC gamma -ray flux on the synchrotron optical flux evident in the post-outburst stage. However, the gamma -ray/optical relationship is linear during the outburst; we attribute this to changes in the Doppler factor. A strong harder-when-brighter spectral dependence is seen both the in gamma-ray and optical non-thermal emission. This hardening can be explained by convexity of the UV-NIR spectrum that moves to higher frequencies owing to an increased Doppler shift as the viewing angle decreases during the outburst stage. The overall pattern of Stokes parameter variations agrees with a model of a radiating blob or shock wave that moves along a helical path down the jet.The St. Petersburg University team acknowledges support from Russian RFBR grant 15-02-00949, and St. Petersburg University research grants 6.38.335.2015 and 6.42.1113.2016. The research at Boston University was funded in part by NASA Fermi Guest Investigator grants NNX08AV65G, NNX10AO59G, NNX10AU15G, NNX11AO37G, NNX11AQ03G, and NNX14AQ58G. The research at Steward Observatory was funded in part by NASA Fermi Guest Investigator grants NNX09AU10G and NNX12AO93G. Acquisition of the MAPCAT data at Calar Alto is performed at the IAA-CSIC and is supported by the Spanish Ministry of Economy and Competitiveness (MINECO) grant AYA2013-40825-P.This research was partially supported by the Scientific Research Fund of the Bulgarian Ministry of Education and Sciences under grant DO 02-137 (BIn-13/09). The Maidanak Observatory team acknowledges support from Uzbekistan Academy of Sciences grant F2-FA-F027.Peer reviewe

Predictores del ajuste de los estudiantes durante la transición a la Universidad en España

Adjustment to university is a major life transition that not all emerging adults manage successfully. The Student University Adjustment Questionnaire is the instrument most commonly used to evaluate this multidimensional construct. Research in Spain on the predisposing factors for successful adjustment to university in emerging adults is scarce relative to the large number of studies carried out in North America. The objective of the present study was to analyze the association between students’ gender, family background, pre-university achievement and adjustment to university. Method: Participants were 300 Spanish fi rst-year students (198 women and 102 men) of mean age 18.02 years. Results: Pre-university achievement was the only signifi cant predictor of academic, social and institutional adjustment. Gender directly affected personal-emotional adjustment and indirectly affected academic adjustment mediated by entry grade. Conclusions: Students’ entry characteristics predict adjustment to university in the fi rst year. These fi ndings have important theoretical and practical implications.Antecedentes: la adaptación a la universidad es una de las principales transiciones vitales que no todos los adultos emergentes afrontan con éxito. El Cuestionario de Adaptación del Estudiante a la Universidad es el instrumento más empleado para evaluar este constructo multidimensional. En España no existen investigaciones sobre los factores que predisponen a los adultos emergentes a una adaptación exitosa a la universidad respecto al número de investigaciones llevadas a cabo con muestras norteamericanas. El objetivo de este estudio es analizar la relación entre el género, el background familiar, la nota de acceso y el ajuste a la universidad. Método: participaron 300 estudiantes españoles de primer año (198 mujeres y 102 hombres) con un promedio de edad de 18,02 años. Resultados: la nota de acceso fue el único predictor signifi cativo del ajuste académico, social e institucional. El género infl uye de una manera directa sobre el ajuste personal-emocional e indirecta sobre el ajuste académico, mediado por la nota de acceso. Conclusiones: las características de entrada del estudiante predicen su adaptación en el primer año de universidad. Estos resultados tienen importantes implicaciones teóricas y prácticas.This study is part of a wider project entitled “La Transición a la Universidad en el Contexto del Espacio Europeo de Educación Superior: Infl uencia del Soporte Social y el Nivel de Integración en el Fracaso/Éxito Académico” [Transition to College in European Higher Education: The Influence of Social Support and Integration on Academic Failure/Success], supported by the Spanish Ministry of Science and Innovation (PSI2011-24535). The author Alexandra M. Araújo received funding from the Portuguese Foundation for Science and Technology (FCT) awarded as a Post-Doctoral Grant, under grant agreement number SFRH/BPD/85856/2012

Predictive Ability of Academic Self-efficacy on Self-concept Dimensions in a Sample of Chilean Adolescents

El objetivo de este estudio fue analizar la capacidad predictiva de la autoeficacia académica sobre las dimensiones del autoconcepto en una muestra de 860 estudiantes chilenos. El análisis de regresión logística reveló que la autoeficacia académica fue un predictor positivo y significativo de las escalas académicas (Matemáticas, Verbal y Académica General), no académicas (Habilidades Físicas, Apariencia Física, Relaciones con el Sexo Opuesto, Relaciones con el Mismo Sexo, Relación con los Padres, Sinceridad- Veracidad), y de la escala de Autoestima, excepto de la escala de Estabilidad Emocional. Esta relación de predicción fue de mayor magnitud con las escalas académicas y autoestima.The aim of this study was to analyze the predictive power of academic self-efficacy on academic self-concept dimensions in a sample of 860 Chilean students. Logistic regression analysis revealed that the academic self-efficacy was a positive and significant predictor of academic scales (Math, Verbal, and General Academic), not academic (Physical Abilities, Physical Appearance, Relationships with the Opposite Sex, Relationships with the Same Sex, Relationship with Parents, Sincerity-Veracity), and Self-Esteem scale, except for the Emotional Stability scale. The predictive value was stronger in the academic dimensions and self-esteem

Population structure and genetic variability in wild and farmed Mediterranean populations of gilthead seabream and European seabass inferred from a 60K combined species SNP array

publishedVersio

Damage-responsive neuro-glial clusters coordinate the recruitment of dormant neural stem cells in Drosophila.

Recruitment of stem cells is crucial for tissue repair. Although stem cell niches can provide important signals, little is known about mechanisms that coordinate the engagement of disseminated stem cells across an injured tissue. In Drosophila, adult brain lesions trigger local recruitment of scattered dormant neural stem cells suggesting a mechanism for creating a transient stem cell activation zone. Here, we find that injury triggers a coordinated response in neuro-glial clusters that promotes the spread of a neuron-derived stem cell factor via glial secretion of the lipocalin-like transporter Swim. Strikingly, swim is induced in a Hif1-α-dependent manner in response to brain hypoxia. Mammalian Swim (Lcn7) is also upregulated in glia of the mouse hippocampus upon brain injury. Our results identify a central role of neuro-glial clusters in promoting neural stem cell activation at a distance, suggesting a conserved function of the HIF1-α/Swim/Wnt module in connecting injury-sensing and regenerative outcomes

Investigaciones arqueológicas en el centro de la provincia de Corrientes: primeros resultados de las prospecciones en el sistema Iberá

Las investigaciones arqueológicas en el centro de la provincia de Corrientes han sido escasas y discontinuas. Con el objetivo de revertir este panorama se iniciaron trabajos de campo en el sector sur y sursureste del macrosistema Iberá (Reserva Provincial Iberá y Parque Nacional Iberá). En este trabajo se presentan los resultados de las actividades de prospección y excavación desarrolladas. Como resultado de las mismas, se identificaron 11 áreas en las que los materiales arqueológicos se presentan en densidades variables y asociados a una matriz sedimentaria con alta proporción de conchillas. En líneas generales, estas se caracterizan por la presencia de material cerámico, lítico, restos óseos humanos y faunísticos, ornamentos, entre otros. A esta información, se integran y discuten los antecedentes para el sector, confirmando el alto potencial arqueológico del área. La evaluación de la red de permeabilidad del sector permitió identificar tres formas posibles de desplazamiento práctico entre la totalidad de los sitios hasta ahora identificados (n= 33)

Innovación pedagógica en toxicología: simulación situada, impacto en el aprendizaje

La propuesta de este trabajo busca implementar modelos de “enseñanza con simulaciones escénicas”, en la cual se logre acercar a los alumnos a situaciones y elementos artificiales, pero lo más similares posible a los de la realidad (Joyce y Weil, 2002), a fin de desarrollar en ellos habilidades prácticas útiles para su vida profesional.Eje 1: Innovación y exploración en cambios de modalidades en cursadasFacultad de Ciencias Exacta

Innovación pedagógica en toxicología: simulación situada, impacto en el aprendizaje

La propuesta de este trabajo busca implementar modelos de “enseñanza con simulaciones escénicas”, en la cual se logre acercar a los alumnos a situaciones y elementos artificiales, pero lo más similares posible a los de la realidad (Joyce y Weil, 2002), a fin de desarrollar en ellos habilidades prácticas útiles para su vida profesional.Eje 1: Innovación y exploración en cambios de modalidades en cursadasFacultad de Ciencias Exacta