Cellular basis of pineal gland development: Emerging role of microglia as phenotype regulator

The adult pineal gland is composed of pinealocytes, astrocytes, microglia, and other interstitial cells that have been described in detail. However, factors that contribute to pineal development have not been fully elucidated, nor have pineal cell lineages been well characterized. We applied systematic double, triple and quadruple labeling of cell-specific markers on prenatal, postnatal and mature rat pineal gland tissue combined with confocal microscopy to provide a comprehensive view of the cellular dynamics and cell lineages that contribute to pineal gland development. The pineal gland begins as an evagination of neuroepithelium in the roof of the third ventricle. The pineal primordium initially consists of radially aligned Pax6+ precursor cells that express vimentin and divide at the ventricular lumen. After the tubular neuroepithelium fuses, the distribution of Pax6+ cells transitions to include rosette-like structures and later, dispersed cells. In the developing gland all dividing cells express Pax6, indicating that Pax6+ precursor cells generate pinealocytes and some interstitial cells. The density of Pax6+ cells decreases across pineal development as a result of cellular differentiation and microglial phagocytosis, but Pax6+ cells remain in the adult gland as a distinct population. Microglial colonization begins after pineal recess formation. Microglial phagocytosis of Pax6+ cells is not common at early stages but increases as microglia colonize the gland. In the postnatal gland microglia affiliate with Tuj1+ nerve fibers, IB4+ blood vessels, and Pax6+ cells. We demonstrate that microglia engulf Pax6+ cells, nerve fibers, and blood vessel-related elements, but not pinealocytes. We conclude that microglia play a role in pineal gland formation and homeostasis by regulating the precursor cell population, remodeling blood vessels and pruning sympathetic nerve fibers.Fil: Ibañez Rodriguez, María Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Cienicas Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Noctor, Stephen C.. University of California; Estados UnidosFil: Muñoz, Estela Maris. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Cienicas Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; Argentin

From English learner to Spanish learner: raciolinguistic beliefs that influence heritage Spanish speaking teacher candidates

This qualitative study explored Spanish-speaking teacher credential students’ beliefs about academic language that might promote or inhibit their decision to become bilingual teachers. Data includes interviews with 11 bilingual teacher candidates who were heritage Spanish speakers. Findings show that most were only aware of English-only educational contexts and did not know that bilingual teaching and the bilingual authorization pathway were options. Their schooling experience fostered English hegemony; even their Spanish classes were pervaded by linguistic purism and elitism. Schools taught them that their registers of Spanish, which they learned at home, were insufficient, inappropriate or incorrect. Consequently, they questioned their ability to become bilingual teachers. Language register and social class were intimately connected in the data. Participants viewed bilingual education as a pathway toward more equitable educational opportunities for Latinx students. Implications include the need for bilingual teacher preparation to address critical sociolinguistics concepts that explore the relationships between language, race and ethnicity in education. Future research is needed to explore how heritage Spanish speaking bilingual teachers enact their beliefs about equity through bilingual education, the challenges they face, and the ways that teacher education programs and professional development providers could support their work

Visible light assisted organosilane assembly on mesoporous silicon films and particles

Porous silicon (PSi) is a versatile matrix with tailorable surface reactivity, which allows the processing of a range of multifunctional films and particles. The biomedical applications of PSi often require a surface capping with organic functionalities. This work shows that visible light can be used to catalyze the assembly of organosilanes on the PSi, as demonstrated with two organosilanes: aminopropyl-triethoxy-silane and perfluorodecyl-triethoxy-silane. We studied the process related to PSi films (PSiFs), which were characterized by X-ray photoelectron spectroscopy (XPS), time of flight secondary ion mass spectroscopy (ToF-SIMS) and field emission scanning electron microscopy (FESEM) before and after a plasma patterning process. The analyses confirmed the surface oxidation and the anchorage of the organosilane backbone. We further highlighted the surface analytical potential of 13 C, 19 F and 29 Si solid-state NMR (SS-NMR) as compared to Fourier transformed infrared spectroscopy (FTIR) in the characterization of functionalized PSi particles (PSiPs). The reduced invasiveness of the organosilanization regarding the PSiPs morphology was confirmed using transmission electron microscopy (TEM) and FESEM. Relevantly, the results obtained on PSiPs complemented those obtained on PSiFs. SS-NMR suggests a number of siloxane bonds between the organosilane and the PSiPs, which does not reach levels of maximum heterogeneous condensation, while ToF-SIMS suggested a certain degree of organosilane polymerization. Additionally, differences among the carbons in the organic (non-hydrolyzable) functionalizing groups are identified, especially in the case of the perfluorodecyl group. The spectroscopic characterization was used to propose a mechanism for the visible light activation of the organosilane assembly, which is based on the initial photoactivated oxidation of the PSi matrixWe acknowledge MSC funding provided by the European Commission through FP7 grant THINFACE (ITN GA 607232) and by Ministerio de Economía y Competitividad through grant NANOPROST (RTC-2016-4776-1

Preparing Bilingual Teachers to Enact Culturally Sustaining Pedagogy

Bilingual students and teachers in the U.S. live in a context where linguistic and ethnic minorities are associated with inferiority. Preparing bilingual teachers of color without explicit attention to issues of race, language, and power would maintain and feed the vicious cycle of linguistic hegemony. With the goal of preparing critically conscious future bilingual teachers equipped to enact culturally sustaining pedagogy (CSP), the authors centered issues of race, language, and power alongside bilingual instructional methodology and theories of bilingualism in their respective bilingual teacher preparation programs. Drawing on bilingual teacher preparation course material, student reflections, and bilingual teacher candidate interviews, they illustrate how two bilingual teacher preparation programs take two distinct approaches to developing bilingual teachers\u27 critical consciousness and CSP practices. In this way, they outline how bilingual teacher educators can prepare and support bilingual teachers to enact CSP with their K-12 students

Locally adaptive density estimation on Riemannian manifolds

In this paper, we consider kernel type estimator with variable bandwidth when the random variables belong in a Riemannian manifolds. We study asymptotic properties such as the consistency and the asymptotic distribution. A simulation study is also considered to evaluate the performance of the proposal. Finally, to illustrate the potential applications of the proposed estimator, we analyse two real examples where two different manifolds are considered

Simulación de flujos de pasajeros y aeronaves en el aeropuerto de Barcelona - El Prat

Un aeropuerto, y en especial uno grande como el Aeropuerto de Barcelona - El Prat, es una infraestructura extremadamente com pleja que tiene que estar muy bien planificada para que pueda asumir su máximo potencial. La simulación permite encontrar sus virtudes y defectos de manera que se hagan evidentes en la planificación, o que se puedan realzar, o solucionar, una vez está oper ativa. La principal ventaja de este trabajo es que el aeropuerto está funcionando, así que la interacción entre simulación y realidad puede ser bidireccional: la simulación se usa para comprender la realidad, y gracias a la toma de datos en condiciones re ales la simulación puede ser dimensionada adecuadamente. Antes de construir el modelo propiamente dicho, el aeropuerto ha sido analizado minuciosamente, y lo que deberían ser los datos devueltos por la simulación se han medido antes en la vida real para q ue coincidieran. Esto hizo que el trabajo se dividiera en dos grandes partes: movimien tos de pasaje y movimientos de aeronav es. Son suficientemente diferentes como para poder separarlos en dos simulaciones distintas, pero están conectadas; algo que ocurra en la terminal de pasajeros puede afectar la escala del avión, y viceversa. Pero como la simulación de los movimientos de aeronaves está centrada en el rodaje y no en la escala, se hizo necesario separar ambas simulaciones para simplificarlas. Los datos o btenidos con las simulaciones se han contrastado con los medidos in situ , para dimensionar y calibrar las simulaciones. Luego, se ha diseñado una interfaz para que sea posible entrar datos (por ejemplo, los de un plan de vuelos de un día particularmente in tenso) y sacar resultados (por ejemplo, los puntos donde habrá más congestión) sin necesidad de tener conocimientos de programación.Así, este trabajo, o la manera de hacerlo, puede ser útil en la gestión (o el diseño) de infraestructuras.An airport, and especially a big airport such as Barcelona - El Prat Airport, is an utterly complex infrastructure that has to be perfectly understood and really well - planned so it can meet its full potential. Through simulation, its virtues and flaws can be traced so that they can become obvious in planning stages, and be enhanced (or solved) once it is operational. The main advantage of this case study is that the airport is already o perational, so there can be a two - way interaction between simulation and reality: simulation can be used to understand reality, and thanks to real - life data collecting the simulation can be more accurately dimensioned. Prior to building the model itself, the airport has been thoroughly analyzed, and what was supposed to be the output data was first collected in real life so that it would match the results of the simulation. This lead to dividing the work in two big areas: passenger movements and aircraft m ovements. Both are different enough to be separated in two simulations, yet they are connected so that something happening in the passenger terminal can affect aircraft turnaround, or vice versa. But as aircraft simulation was focused on taxiing in and out of the terminal and not on the turnaround itself, it became necessary to separate both simulations in order to simplify them. Data collected from the simulations has been paired with the one obtained from real - life measurements, so that they could be cal ibrated and dimensioned according to these conditions. Then, and interface has been designed to make it possible to enter data (i.e. of a peak - day schedule) and get results (i.e., the places where congestion will occur) with no programming skills at all. This work may thus be useful in the design or management of new or existing infrastructur