368 research outputs found

    Characterization of argF Specialized Transducing Derivatives of Bacteriophage P1

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    An exploratory study of the process of mental health consultation to the schools

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    Thesis (M.S.)--Boston Universit

    La reflexión del profesorado experto sobre situaciones de la práctica

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    [spa] El mundo actual vive muchos cambios que retan la educación. La formación docente y el desarrollo profesional continuo son ubicados como elementos centrales de los programas de mejora de los sistemas educativos. Al respecto, la investigación ha demostrado que la reflexión sobre la docencia y, concretamente, sobre las situaciones de la práctica, permite al profesorado desarrollar nuevos conocimientos para enfrentar la realidad docente. Desde este punto de vista, el objetivo general del presente estudio es comprender cómo profesorado experto de educación secundaria reflexiona individual y conjuntamente con otros/as compañeros/as, para clarificar cuestionamientos de situaciones concretas de su práctica. Para cumplir con el objetivo principal se plantearon objetivos específicos encaminados a identificar y analizar las características de la reflexión individual y la reflexión conjunta sobre situaciones de la práctica, así como conocer y describir las percepciones del profesorado académico y técnico respecto a la reflexión. La reflexión se estudia desde una perspectiva sociocultural que considera que el aprendizaje se da como un proceso mediado social y culturalmente, que la reflexión sobre las situaciones de la práctica es la clave para la mejora del conocimiento práctico y que las ayudas al aprendizaje de la reflexión conjunta con otros son esenciales para su mejora (Clarà, 2013, 2015; Dewey, 2007; Schön, 1987; Mauri et al., 2017). Metodológicamente, el trabajo desarrolla un estudio exploratorio sin ánimo de generalización, de corte cualitativo, sustentado en el paradigma interpretativo, en el que participaron 30 profesores, 15 del área académica y 15 del área técnica, de la Escuela Tecnológica Instituto Técnico Central (ETITC), ubicada en Bogotá (Colombia). La recolección de datos se realizó a través de los siguientes instrumentos y procedimientos: entrevistas semiestructuradas, narrativas escritas, registro audiovisual de sesiones de reflexión conjunta del profesorado en dos grupos de 5 profesores/as cada uno, y grupos de discusión de valoración de las sesiones de reflexión conjunta y de valoración final de todo el proceso de reflexión individual y reflexión conjunta desarrollado. Los datos obtenidos fueron analizados, esencialmente, a través de análisis temático (Braun & Clarke, 2006) y del modelo de análisis de la interactividad (Coll et al., 2008). Los principales resultados se refieren a los procesos de reflexión individual y conjunta. En cuanto a la reflexión individual, se aporta evidencia empírica de que el uso de las situaciones inciertas de la práctica facilita el proceso reflexivo del profesorado; se ha identificado una estructura-tipo en la organización de la reflexión individual en la narrativa sobre las situaciones de la práctica; se apunta la importancia del encuadre que el profesorado construye en su conversación con la situación, en la que interviene su experiencia y la representación que tiene sobre la enseñanza y sobre la ayuda educativa que presta a los estudiantes. Los resultados muestran, que el conocimiento que utiliza el profesorado para clarificar la situación que le causa sorpresa o incertidumbre y desea comprender mejor, es más de tipo práctico que teórico. Asimismo, los resultados muestran la potencialidad que tiene, desde el punto de vista metodológico, el uso de la narrativa como instrumento para la reflexión y para elicitar el conocimiento práctico del profesorado experto estudiado. En cuanto a la reflexión conjunta del profesorado sobre las situaciones de la práctica se observa, a diferencia de la reflexión individual, un análisis más preventivo que interventivo, es decir no actúa para resolver problemáticas, sino que puede preverlas y en ellas el profesor se implica en primera persona, permitiendo una mirada autocrítica que facilita la mejora personal de la práctica. El grupo de profesorado académico y el grupo de profesorado técnico estructuran su actividad de reflexión conjunta de modos distintos, si bien en ambos casos se facilita la comprensión compartida de la situación. Sin embargo, se observa que están en un proceso inicial de colaboración, puesto que es su primera experiencia al respecto y para avanzar en la reflexión colaborativa se requiere mayor práctica y, probablemente, ayuda específica. Los resultados también muestran diferencias entre el profesorado académico y el técnico tanto en la reflexión individual como conjunta: en general, el profesorado académico presenta con más detalle las situaciones de la práctica mientras que el profesorado técnico es más pragmático en sus interpretaciones, aspecto que probablemente se encuentra correlacionado con la diferencia de enfoques del proceso de enseñanza y aprendizaje de una y otra área. Finalmente, los resultados permiten apuntar algunas prioridades en la formación del profesorado basadas en los procesos de reflexión colaborativa, así como la necesidad de continuar investigando la voz y las actuaciones del profesorado sobre la reflexión individual y conjunta para avanzar de modo contextualizado y con sentido profesional en la mejora de su aprendizaje y desarrollo docente.[eng] Today's world is experiencing many changes which challenge education. Teacher training and continuous professional development are located as central elements of programs to improve educational systems. In this regard, research has shown that reflection on teaching and, specifically, on practice situations, allows teachers to develop new knowledge to face the teaching reality. From this point of view, the general objective of this study is to understand how expert secondary school teachers reflect individually and along with other colleagues, to clarify questions about specific situations in their practice. In order to achieve the main objective, specific objectives were established aimed at identifying and analyzing the characteristics of individual reflection and joint reflection on practice situations, as well as knowing and describing the perceptions of academic and technical teachers regarding reflection. Reflection is studied from a sociocultural perspective that considers that learning occurs as a socially and culturally mediated process, that reflection on practice situations is the key to improving practical knowledge, and aids to learning joint reflection with others are essential for your improvement. (Clarà, 2013, 2015; Dewey, 2007; Schön, 1987; Mauri et al., 2017). Methodologically, the work develops an exploratory study without the intention of generalization, of a qualitative nature, based on the interpretive paradigm, in which 30 professors participated, 15 from the academic area and 15 from the technical area, from the Technological School of the Central Technical Institute (ETITC), located in Bogotá (Colombia). Data collection was carried out through the following instruments and procedures: semi-structured interviews, written narratives, audiovisual recording of joint reflection sessions by teachers in two groups of 5 teachers each, discussion groups to assess the joint reflection sessions, and final assessment of the entire process of individual reflection and joint reflection developed. The data obtained were essentially analyzed through thematic analysis (Braun & Clarke, 2006) and the interactivity analysis model (Coll et al., 2008). The main results refer to individual and joint reflection processes. Regarding individual reflection, empirical evidence is provided that the use of uncertain situations in practice facilitates the reflective process of teachers; a type-structure has been identified in the organization of individual reflection in the narrative about practice situations; the importance of the frame that teachers construct in their conversation with the situation is pointed out, in which their experience and the representation they have about teaching and about the educational help they provide to students intervene. The results show that the knowledge that teachers use to clarify the situation that causes them surprise or uncertainty and they want to understand it better, is more practical than theoretical. Likewise, the results show the potential that the use of narrative as an instrument for reflection and to elicit the practical knowledge of the expert teachers studied has from a methodological point of view. Regarding the joint reflection of the teaching staff on the situations of practice, it is observed, unlike individual reflection, a more preventive than interventional analysis, meaning that it does not act to solve problems but can foresee them and in them the teacher is involved in first person, allowing a self-critical look that facilitates the personal improvement of the practice. The academic faculty group and the technical faculty group structure their joint reflection activity in different ways, although in both cases a shared understanding of the situation is facilitated. Nevertheless, it is observed that they are in an initial process of collaboration, since it is their first experience in this regard and to advance in collaborative reflection more practice is required and, probably, specific help. The results also show differences between academic and technical teachers both in individual and joint reflection: in general, academic teachers present practical situations in more detail while technical teachers are more pragmatic in their interpretations, an aspect that probably It is correlated with the difference in approaches to the teaching and learning process of one area and another. Finally, the results allow pointing out some priorities in teacher training based on collaborative reflection processes, as well as the need to continue investigating the voice and actions of teachers on individual and joint reflection in order to advance in a contextualized and professional way in the improvement of their learning and teaching development

    A study of effectiveness of simulated data in classifying Alzheimer's disease status using MRS parameters

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    In vivo magnetic resonance spectroscopy, or MRS, has the potential to identify meaningful differences in the neurochemical profiles of patients with Alzheimer's disease (AD) relative to healthy controls, especially at ultra-high field (7 Tesla). Classification algorithms applied to such data could, theoretically, aid in disease diagnosis or act as an indicator of the effectiveness of a treatment. A common limitation when applying classification algorithms to such data is sample size, which arises from difficulty in recruitment of individuals with AD. Classification algorithms applied to small datasets may benefit from additional training data simulated from Bayesian networks that are learned via hill-climbing. Ultra-high field single voxel MRS and MRI data from Marjanska et al (2019) were used to explore the effect that including simulated data in the training of classification algorithms has on the ability to correctly classify AD status [2]. Three hill climbing methods, hill climbing scored via the Bayesian information criterion (BIC), hill climbing scored via the Akaike information criterion (AIC), and max-min hill climbing scored via BIC, were tested using the original data and data in which each Alzheimer's observation is doubled in search for the network that could produce the highest posterior predictive correlation across ascorbate, percent grey matter, and signal to noise ratio. The effect of including data simulated in the resulting manner was then characterized across three classification algorithms (Extreme Gradient Boosting, random forest, and support vector machine) and three data sets (original AD and control data from Marjanska et al (2019), Marjanska et al (2019) data reflected as principal components, and Marjanska et al (2019) data with additional controls from The Lifespan Human Connectome Project in Aging used in the training and simulation process) [3]. Variables used to predict AD status were mostly from MRS derived data, consisting of 14 water-referenced neurochemical concentrations, signal to noise ratio, and linewidth, with few variables from MRI derived data, consisting of percent gray matter, percent white matter, percent cerebro-spinal fluid relative to the volume of interest. The strongest findings regarding structure learning arose from hill climbing scored via BIC using data in which every AD observation was over-sampled. The inclusion of data simulated from Bayesian networks whose structures were derived via this method did not widely lead to higher average sensitivity, specificity, or overall accuracy.Includes bibliographical references

    Benthic invertebrates that form habitat on deep banks off southern California, with special reference to deep sea coral

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    There is increasing interest in the potential impacts that fishing activities have on megafaunal benthic invertebrates occurring in continental shelf and slope ecosystems. We examined how the structure, size, and high-density aggregations of invertebrates provided structural relief for fishes in continental shelf and slope ecosystems off southern California. We made 112 dives in a submersible at 32−320 m water depth, surveying a variety of habitats from high-relief rock to flat sand and mud. Using quantitative video transect methods, we made 12,360 observations of 15 structure-form-ing invertebrate taxa and 521,898 individuals. We estimated size and incidence of epizoic animals on 9105 sponges, black corals, and gorgonians. Size variation among structure-form-ing invertebrates was significant and 90% of the individuals were <0.5 m high. Less than 1% of the observations of organisms actually sheltering in or located on invertebrates involved fishes. From the analysis of spatial associations between fishes and large invertebrates, six of 108 fish species were found more often adjacent to invertebrate colonies than the number of fish predicted by the fish-density data from transects. This finding indicates that there may be spatial associations that do not necessarily include physical contact with the sponges and corals. However, the median distances between these six fish species and the invertebrates were not particularly small (1.0−5.5 m). Thus, it is likely that these fishes and invertebrates are present together in the same habitats but that there is not necessarily a functional relationship between these groups of organisms. Regardless of their associations with fishes, these invertebrates provide structure and diversity for continental shelf ecosystems off southern California and certainly deserve the attention of scientists undertaking future conservation efforts

    Discerning Differences between Producer Groups and Organic Adoption Barriers in Texas

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    The number of certified organic operations in Texas has remained relatively stagnant while nationally the organic food sector has experienced double-digit growth. To understand why this occurring, a survey was distributed to a random sample of 4,006 Texas producers. The results will assist in developing strategies to promote the growth of organic production in Texas.Crop Production/Industries,

    DETERMINATION OF METHODS TO EFFECTIVELY STUDY INTERFACES IN SODIUM SOLID STATE BATTERIES

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    As countries across the globe pledge to decrease their carbon footprint, the demand for sustainable resources has grown drastically. An increase in the energy density of electrochemical energy storage devices would advance the use of low-carbon electrical energy sources. Successful implementation of a metallic anode may allow for this increase; however, alkali metal electrodes are hindered by their reactive nature and instability at the electrode-electrolyte interface. These challenges extend to both liquid and solid electrolytes, though integration of solid electrolytes shows promise of obtaining higher energy batteries. The solid metal electrode-solid electrolyte interface is largely unexplored, but we have determined that the application of stack pressure allows for increased cyclability in all solid-state cells. Further, it is of utmost importance to achieve a pristine interface through heat treatment and polishing procedures. Data found in the literature is difficult to compare; thus, careful reporting of experimental conditions is important to efficient advancement of research
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