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Adult skeletal muscle has robust regenerative capabilities due to the presence of a resident stem cell \ud population called satellite cells. Muscle injury leads to these normally quiescent cells becoming molecularly \ud and metabolically activated and embarking on a program of proliferation, migration, differentiation, and fusion \ud culminating in the repair of damaged tissue. These processes are highly coordinated by paracrine signaling \ud events that drive cytoskeletal rearrangement and cell-cell communication. Pannexins are a family of \ud transmembrane channel proteins that mediate paracrine signaling by ATP release. It is known that Pannexin1 \ud (Panx1) is expressed in skeletal muscle, however, the role of Panx1 during skeletal muscle development and \ud regeneration remains poorly understood. Here we show that Panx1 is expressed on the surface of myoblasts \ud and its expression is rapidly increased upon induction of differentiation and that Panx1-/- mice exhibit impaired \ud muscle regeneration after injury. Panx1-/- myoblasts activate the myogenic differentiation program normally, \ud but display marked deficits in migration and fusion. Mechanistically, we show that Panx1 activates P2 class \ud purinergic receptors, which in turn mediate a lipid signaling cascade in myoblasts. This signaling induces bleb�driven amoeboid movement that in turn supports myoblast migration and fusion. Finally, we show that Panx1 \ud is involved in the regulation of cell-matrix interaction through the induction of ADAMTS (Disintegrin-like and \ud Metalloprotease domain with Thrombospondin-type 5) proteins that help remodel the extracellular matrix.\ud These studies reveal a novel role for lipid-based signaling pathways activated by Panx1 in the coordination of \ud myoblast activities essential for skeletal muscle regeneration.

The research focuses on the experience of nine Chilean beginner teachers staying in vulnerable schools. From an ecological approach of the teacher agency and a biographical narrative methodology, different dimensions are articulated in understanding the phenomenon. Four central themes are proposed, namely: life story: finding the source of sustenance and professional meaning; the link with students as the root of permanence; the composition of a school context as a protector and facilitator of teaching; and imagined futures in education: purposes and possibilities of projection. The findings allow progress towards an integrated and multidimensional understanding of permanence in schools and provide communicating threads between dimensions of teachers’ personal environments interwoven with the daily, relational, and systemic environments in which the profession unfolds. La investigación profundiza en la experiencia de permanencia de nueve profesores principiantes chilenos de educación secundaria que se desempeñan en escuelas vulnerables. A partir de un enfoque ecológico de la agencia docente y una metodología biográfica narrativa se articulan distintas dimensiones en la comprensión del fenómeno. Se develan cuatro temáticas centrales, a saber: historia de vida, encontrando el origen del sostenimiento y sentido profesional; el vínculo con los estudiantes como raíz de la permanencia; la composición de un contexto escolar como protector y facilitador de la labor docente; y futuros imaginados en educación: propósitos y posibilidades de proyección. Los hallazgos permiten avanzar hacia una comprensión integrada y multidimensional de la permanencia en las escuelas, que provee hilos comunicantes entre dimensiones del ámbito personal de los docentes que se entrelazan con los entornos cotidianos, relacionales y sistémicos en los cuales se despliega la profesión. La recherche analyse l’expérience de la permanence de neuf professeurs chiliens en debut de carrière dans des lycées considérés vulnérables. Plusieurs niveaux de compréhension du phénomène s’articulent autour d’une approche écologique du travail d’enseignement et d’une méthodologie des récits de vie. Quatre grands thèmes sont traités : l’histoire de vie, pour cerner le socle de leur motivation et de leur sens professionnel ; les liens noués avec les élèves, qui seraient à la racine de leur permanence dans les établissements ; la construction d'un contexte scolaire, vu comme protecteur et favorable au travail d’enseignement ; et des futurs imaginés dans l’enseignement en termes d’objectifs et de possibilités de projection. Les résultats permettent d’avancer vers une compréhension intégrée et multidimensionnelle de la permanence dans les écoles, assurant un flux communicationnel entre les dimensions de la sphère personnelle des enseignants, qui s’entrelacent aux environnements quotidiens, relationnels et systémiques dans lesquels la profession se déroule. A pesquisa aprofunda a experiência da permanência de nove professores principiantes chilenos do ensino médio que lecionam em escolas vulneráveis. A partir de uma abordagem ecológica do trabalho docente e de uma metodologia biográfica narrativa são articuladas diversas dimensões da compreensão do fenômeno. Revelam-se quatro temas principais, como: história de vida, encontrando a origem da sustentação e do sentido profissional; o vínculo com os estudantes como raiz da permanência; a composição de um contexto escolar como protetor e facilitador do trabalho docente; e futuros imaginados na educação: propósitos e possibilidades de projeção. Os achados permitem avançar rumo a uma compreensão integrada e multidimensional da permanência nas escolas, que provê um fluxo de comunicação entre dimensões do âmbito pessoal dos professores que se entrelaçam com os entornos cotidianos, relacionais e sistêmicos nos quais a profissão se desenrola.

Following sensory deprivation such as deafness, compensatory plasticity underlies the reorganization of sensory-specific brain areas to process remaining intact modalities. Previous studies have explored microstructural consequences throughout the brain following auditory deprivation, including the effect of deafness on cerebral water diffusion. However, nearly all investigations have studied these neuronal changes in humans rather than animal models. The present study investigates microstructural differences between 19 hearing and 27 early-deaf cats via diffusion tensor imaging (DTI). Diffusivity scalars were compared within 155 grey and 21 white matter regions. Results indicate structural plasticity in various regions throughout the deaf brain in both tissues, including perirhinal cortex, frontalis agranularis, as well as corpus callosum, superior longitudinal fasciculus, and more. This is the first study to examine DTI alterations following auditory deprivation in cats perhaps due to compensatory plasticity, overall demonstrating that early-deafness incites alterations throughout the brain.

More than 40% of Chilean teachers leave the profession during the first years of their professional practice. Also, when considering environments of greater vulnerability in schools, this problem is exacerbated. In this context, this study proposes an approach to the permanence experiences of two beginning teachers who work in Chilean schools with high vulnerability rates. Based on an ecological approach of the teacher agency it was possible to enter into an understanding of such experiences in a multidimensional and integrated manner. The study uses a biographical narrative approach that puts the experience of permanence at the center of the analysis. Based on the narratives of Andrea and Ignacio, a continuous network of decisions is evidence that leads them to remain in their schools, which is not exempt from moments of discontinuity and questioning., Más del 40% de los docentes chilenos abandona la profesión durante los primeros años de ejercicio profesional. Adicionalmente, al considerar entornos de mayor vulnerabilidad escolar esta problemática se ve agudizada. Considerando este contexto, este estudio propone un acercamiento a las experiencias de permanencia de dos profesores principiantes que se desempeñan en escuelas chilenas con altos índices de vulnerabilidad. A partir de un enfoque ecológico de la agencia docente fue posible adentrarse en la comprensión de dichas experiencias de forma multidimensional e integrada. Se utiliza una aproximación biográfica narrativa que permite poner en el centro del análisis la experiencia de permanencia. En base a las narraciones de Andrea e Ignacio se evidencia un entramado continuo de decisiones que los llevan a permanecer en sus escuelas, que no está exento de momentos de discontinuidad y cuestionamientos.

The literature review presents a systematization of the main empirical findings reported around the factors related to beginning teachers’ mobility decisions. The period considered is 1999 to 2019 to select and analyze 46 relevant articles within the topic. Two main categories are established to systematize the contributions of the research examined. The first category groups the findings associated with contextual factors, such as: school management; working conditions; professional development opportunities, support and collaboration at the school level. The second group considers findings associated with personal factors, such as: the relationship with students, perception of self-efficacy and positive events or experience; resilience, workload and perseverance; and initial teacher training. Based on this review, the need is identified to advance in the strengthening of theoretical frameworks for the study of career decisions of beginning teachers. In particular, generate more comprehensive and integrated research that considers not only factors of abandonment, rotation, or permanence of beginning teachers in isolation, but also identifies conditions that allow teachers to persevere in their jobs, under conditions of permanent professional satisfaction and development. Se sistematizan los principales hallazgos empíricos relativos a los factores relacionados a las decisiones de movilidad de profesores principiantes. Se considera el período comprendido entre 1999 a 2019 para la selección y análisis de 46 artículos. Se establecen dos grandes categorías para sistematizar los aportes de las investigaciones examinadas. La primera incluye aquellos asociados a factores contextuales, tales como: gestión escolar; condiciones laborales; oportunidades de desarrollo profesional, apoyo y colaboración a nivel escolar. En la segunda, se consideran los hallazgos asociados a factores personales, tales como: la relación con los estudiantes, la percepción de autoeficacia y vivencia de eventos positivos; la resiliencia del maestro, el manejo de la carga laboral y la perseverancia; la formación inicial docente. En base a esta revisión se sugiere robustecer los marcos teóricos desde los cuáles se aborda la temática y generar investigación más comprehensiva e integrada, que considere no solo factores de abandono, rotación o permanencia de los maestros principiantes de forma aislada, sino que avance hacia la identificación de condiciones que permitan perseverar a los docentes en sus puestos de trabajo, bajo condiciones de satisfacción y desarrollo profesional permanentes.