Cultivating a Community of Practice Among Student Teachers and Cooperating Teachers

This study examined the experience of four student teachers and their supervising teachers who participated in a Community of Practice (CoP) during their internship semester. Their experience can be separated into the four key components of a Community of Practice: (a) structure, (b) processes, (c) content, and (d) conditions

Sin ti no soy nada. Participación de usuarios en Salud Mental

La participación de los usuarios es un derecho compartido con todos los ciudadanos y ciudadanas. En estos tiempos en los que la distancia entre los grupos que ostentan el poder de decisión el poder de decisión y la población es tan grande, podemos comprender mejor qué significa ser privado de este derecho por padecer una enfermedad mental

Niveles de conciencia. Perspectiva socio-cultural

En Esta Contribución Se Aborda El Tema De La Conciencia Desde Un Punto De Vistasociocultural. Se Propone Un Modelo Cuya Categoría Central Es La De Nivel Deconciencia. Seguidamente Se Exponen Cuatro Niveles Que Se Consideranfundamentales Para Avanzar En El Conocimiento Del Papel Que La Conciencia Tieneen La Vida De Las Personas

Growth of Sobolev norms in the cubic defocusing nonlinear Schrödinger equation

We consider the cubic defocusing nonlinear Schrödinger equation in the two dimensional torus. Fix s>1. Recently Colliander, Keel, Staffilani, Tao and Takaoka proved the existence of solutions with s -Sobolev norm growing in time. We establish the existence of solutions with polynomial time estimates. More exactly, there is c>0 such that for any K»1 we find a solution u and a time T such that ¿u(T)¿Hs=K¿u(0)¿Hs. Moreover, the time T satisfies the polynomial bound 0Peer ReviewedPostprint (author's final draft

Dynamical Bonding Driving Mixed Valency in a Metal Boride

Samarium hexaboride is an anomaly, having many exotic and seemingly mutually incompatible properties. It was proposed to be a mixed-valent semiconductor, and later - a topological Kondo insulator, and yet has a Fermi surface despite being an insulator. We propose a new and unified understanding of SmB$_6$ centered on the hitherto unrecognized dynamical bonding effect: the coexistence of two Sm-B bonding modes within SmB$_6$, corresponding to different oxidation states of the Sm. The mixed valency arises in SmB$_6$ from thermal population of these distinct minima enabled by motion of B. Our model simultaneously explains the thermal valence fluctuations, appearance of magnetic Fermi surface, excess entropy at low temperatures, pressure-induced phase transitions, and related features in Raman spectra and their unexpected dependence on temperature and boron isotope

The nematode caenorhabditis elegans as an emerging biological model to study endocrine disruptor pesticides

Un disruptor endócrino (DE) es una sustancia exógena capaz de desbalancear el sistema endócrino, afectando funciones vitales como la reproducción, el metabolismo, el crecimiento, la función cardíaca y el balance de minerales. La complejidad del tema obliga a los investigadores, a la industria y a los entes reguladores a estudiar de manera conjunta los efectos potenciales de la exposición a DE. Para esclarecer las problemáticas asociadas, es necesario proponer un modelo experimental alternativo al de mamíferos, que les permitirá adecuarse a las futuras normativas internacionales. Este proyecto plantea el uso del nematodo Caenorhabditis eleganscomo modelo biológico para el estudio de los mecanismos de acción de los plaguicidas con potencial actividad disruptora endócrina. Este organismo ha resultado un excelente modelo in vivoen disciplinas como biología del desarrollo, genética, ciencias médicas y toxicología. Su ciclo de vida corto, su fácil y bajo costo de mantenimiento y la abundante bibliografía acerca de su fisiología posibilitan el desarrollo de pruebas toxicológicas eficientes y económicas. La información alcanzada en este estudio aportará datos importantes para la estimación de riesgo de plaguicidas con actividad disruptora endócrina y para la innovación de las políticas reguladoras de protección de la salud humana y del medioambiente.An endocrine disruptor (ED) is an exogenous substance that causes an imbalance in the endocrine system and adversely affects many biological functions such as reproduction, metabolism, growth, heart rate and fluid balance. The complexity of this matter requires an interdisciplinary approach from researchers, industry societies and control organizations to fully understand the potential effects of ED compounds. On top of that more important issues that are pending to be solved like the large amount of compounds to be tested for endocrine disruption activity and to establish an in vivo biological model that embrace animal protection regulation to perform all these new set of experiments. This project suggests the nematode Caenorhabditis elegans as a biological model to study the mechanisms of action of pesticides with putative endocrine disrupting activity. C. elegans has been studied and used as a model organism in several disciplines such as developmental biology, genetics, medical sciences and toxicology. Its short life cycle, simplicity and low cost maintenance together with the large amount of literature on its biology makes C. elegans a perfect tool to develop protocols for efficient and economical compounds screening. The results obtained in this study would provide important data that will help to estimate the risk of pesticides in relation with its endocrine disrupting activity. This information will be useful to modify regulatory policies in order to protect the environment and human health.Fil: Moya, Aldana. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal. Área de Protección Vegetal; ArgentinaFil: Kronberg, Maria Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Clavijo Lara, Araceli Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Mazzarella, Daniel. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal. Área de Protección Vegetal; Argentina. Ministerio de Agricultura, Ganadería, Pesca y Alimento. Servicio Nacional de Sanidad y Calidad Agroalimentaria; ArgentinaFil: Pagano, Eduardo Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Munarriz, Eliana Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; Argentin

Strong spin-dependent negative differential resistance in composite graphene superlattices

We find clear signatures of spin-dependent negative differential resistance in compound systems comprising a graphene nanoribbon and a set of ferromagnetic insulator strips deposited on top of it. The periodic array of ferromagnetic strips induces a proximity exchange splitting of the electronic states in graphene, resulting in the appearance of a superlattice with a spin-dependent energy spectrum. The electric current through the device can be highly polarized and both the current and its polarization manifest nonmonotonic dependence on the bias voltage. The device operates therefore as an Esaki spin diode, which opens possibilities to design new spintronic circuits

On the Role of Ferromagnetic Interactions in Highly Active Mo-Based Catalysts for Ammonia Synthesis

Reactions involving nitrogen fixation and transfer are of great industrial interest. In this regard, unveiling all the physical principles that determine their activity would be enormously beneficial for the rational design of novel catalysts with improved performance. Within this context, this work explores the activity of bulk molybdenum-based transition metal nitrides in ammonia synthesis. Our results highlight that the most active compositions show increasing ferromagnetism in the metal–nitrogen bonds, which constitute the active sites. We observe that the total spin accumulated in the bonds at the active sites is a physically meaningful descriptor to discriminate optimum catalysts. Higher activities are associated with ferromagnetic phases, and the underlying reason is an enhanced overlapping of the electronic wavefunctions; which also make the reaction steps spin-sensitive. These finding provides strong evidence of the general influence of electrons magnetic moment in catalysis, being part of the specific field of spintro-catalysis

Asymptotic density of collision orbits in the restricted circular planar 3 body problem

This is a post-peer-review, pre-copyedit version of an article published in Archive for rational mechanics and analysis. The final authenticated version is available online at: http://dx.doi.org/10.1007/s00205-019-01368-7”For the Restricted Circular Planar 3 Body Problem, we show that there exists an open set U in phase space of fixed measure, where the set of initial points which lead to collision is O(µ120) dense as µ¿0 .Postprint (author's final draft