84 research outputs found

    Pensando en los directores: ¿cómo concilian las presiones externas con la redefinición interna de su rol?

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    Observando los más recientes cambios en el contexto de la política educativa, es difícil subestimar el rol central del director. Los directores deben ejercer simultáneamente diferentes roles e implementar actividades de una variada naturaleza. Como un líder pedagógico, el/ella debe ser capaz de crear lazos de apoyo entre el centro educativo y el nivel de la clase. El aprendizaje individual y el desarrollo profesional de los docentes deben estar vinculados a, y apoyados por, un desarrollo organizacional apropiado. Como un gerente de proyecto, el director debe desarrollar e implementar un plan específico de modo de resolver problemas que le sean señalados por el cuerpo de inspectores.Ambas tareas —líder pedagógico y gerente de proyecto— son ilustradas en este trabajo

    Walk-through flat panel total-body PET: a patient-centered design for high throughput imaging at lower cost using DOI-capable high-resolution monolithic detectors.

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    PURPOSE Long axial field-of-view (LAFOV) systems have a much higher sensitivity than standard axial field-of-view (SAFOV) PET systems for imaging the torso or full body, which allows faster and/or lower dose imaging. Despite its very high sensitivity, current total-body PET (TB-PET) throughput is limited by patient handling (positioning on the bed) and often a shortage of available personnel. This factor, combined with high system costs, makes it hard to justify the implementation of these systems for many academic and nearly all routine nuclear medicine departments. We, therefore, propose a novel, cost-effective, dual flat panel TB-PET system for patients in upright standing positions to avoid the time-consuming positioning on a PET-CT table; the walk-through (WT) TB-PET. We describe a patient-centered, flat panel PET design that offers very efficient patient throughput and uses monolithic detectors (with BGO or LYSO) with depth-of-interaction (DOI) capabilities and high intrinsic spatial resolution. We compare system sensitivity, component costs, and patient throughput of the proposed WT-TB-PET to a SAFOV (= 26 cm) and a LAFOV (= 106 cm) LSO PET systems. METHODS Patient width, height (= top head to start of thighs) and depth (= distance from the bed to front of patient) were derived from 40 randomly selected PET-CT scans to define the design dimensions of the WT-TB-PET. We compare this new PET system to the commercially available Siemens Biograph Vision 600 (SAFOV) and Siemens Quadra (LAFOV) PET-CT in terms of component costs, system sensitivity, and patient throughput. System cost comparison was based on estimating the cost of the two main components in the PET system (Silicon Photomultipliers (SiPMs) and scintillators). Sensitivity values were determined using Gate Monte Carlo simulations. Patient throughput times (including CT and scout scan, patient positioning on bed and transfer) were recorded for 1 day on a Siemens Vision 600 PET. These timing values were then used to estimate the expected patient throughput (assuming an equal patient radiotracer injected activity to patients and considering differences in system sensitivity and time-of-flight information) for WT-TB-PET, SAFOV and LAFOV PET. RESULTS The WT-TB-PET is composed of two flat panels; each is 70 cm wide and 106 cm high, with a 50-cm gap between both panels. These design dimensions were justified by the patient sizes measured from the 40 random PET-CT scans. Each panel consists of 14 × 20 monolithic BGO detector blocks that are 50 × 50 × 16 mm in size and are coupled to a readout with 6 × 6 mm SiPMs arrays. For the WT-TB-PET, the detector surface is reduced by a factor of 1.9 and the scintillator volume by a factor of 2.2 compared to LAFOV PET systems, while demonstrating comparable sensitivity and much better uniform spatial resolution (< 2 mm in all directions over the FOV). The estimated component cost for the WT-TB-PET is 3.3 × lower than that of a 106 cm LAFOV system and only 20% higher than the PET component costs of a SAFOV. The estimated maximum number of patients scanned on a standard 8-h working day increases from 28 (for SAFOV) to 53-60 (for LAFOV in limited/full acceptance) to 87 (for the WT-TB-PET). By scanning faster (more patients), the amount of ordered activity per patient can be reduced drastically: the WT-TB-PET requires 66% less ordered activity per patient than a SAFOV. CONCLUSIONS We propose a monolithic BGO or LYSO-based WT-TB-PET system with DOI measurements that departs from the classical patient positioning on a table and allows patients to stand upright between two flat panels. The WT-TB-PET system provides a solution to achieve a much lower cost TB-PET approaching the cost of a SAFOV system. High patient throughput is increased by fast patient positioning between two vertical flat panel detectors of high sensitivity. High spatial resolution (< 2 mm) uniform over the FOV is obtained by using DOI-capable monolithic scintillators

    Approaches and challenges to the study of loess—Introduction to the LoessFest Special Issue

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    In September 2016, the annual meeting of the International Union for Quaternary Research's Loess and Pedostratigraphy Focus Group, traditionally referred to as a LoessFest, met in Eau Claire, Wisconsin, USA. The 2016 LoessFest focused on thin loess deposits and loess transportation surfaces. This LoessFest included 75 registered participants from 10 countries. Almost half of the participants were from outside the United States, and 18 of the participants were students. This review is the introduction to the special issue for Quaternary Research that originated from presentations and discussions at the 2016 LoessFest. This introduction highlights current understanding and ongoing work on loess in various regions of the world and provides brief summaries of some of the current approaches/strategies used to study loess deposits

    The anterior temporal lobes support residual comprehension in Wernicke’s aphasia

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    Wernicke’s aphasia occurs following a stroke to classical language comprehension regions in the left temporoparietal cortex. Consequently, auditory-verbal comprehension is significantly impaired in Wernicke’s aphasia but the capacity to comprehend visually presented materials (written words and pictures) is partially spared. This study used fMRI to investigate the neural basis of written word and picture semantic processing in Wernicke’s aphasia, with the wider aim of examining how the semantic system is altered following damage to the classical comprehension regions. Twelve participants with Wernicke’s aphasia and twelve control participants performed semantic animate-inanimate judgements and a visual height judgement baseline task. Whole brain and ROI analysis in Wernicke’s aphasia and control participants found that semantic judgements were underpinned by activation in the ventral and anterior temporal lobes bilaterally. The Wernicke’s aphasia group displayed an “over-activation” in comparison to control participants, indicating that anterior temporal lobe regions become increasingly influential following reduction in posterior semantic resources. Semantic processing of written words in Wernicke’s aphasia was additionally supported by recruitment of the right anterior superior temporal lobe, a region previously associated with recovery from auditory-verbal comprehension impairments. Overall, the results concord with models which indicate that the anterior temporal lobes are crucial for multimodal semantic processing and that these regions may be accessed without support from classic posterior comprehension regions

    Quality indicators as a tool in improving the introduction of new medicines

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    Quality indicators are increasingly used as a tool to achieve safe and quality clinical care, cost-effective therapy, for professional learning, remuneration, accreditation and financial incentives. A substantial number focus on drug therapy but few address the introduction of new medicines even though this is a burning issue. The objective was to describe the issues and challenges in designing and implementing a transparent indicator framework and evaluation protocol for the introduction of new medicines and to provide guidance on how to apply quality indicators in the managed entry of new medicines. Quality indicators need to be developed early to assess whether new medicines are introduced appropriately. A number of key factors need to be addressed when developing, applying and evaluating indicators including dimensions of quality, suggested testing protocols, potential data sources, key implementation factors such as intended and unintended consequences, budget impact and cost-effectiveness, assuring the involvement of the medical professions, patients and the public, and reliable and easy-to-use computerized tools for data collection and management. Transparent approaches include the need for any quality indicators developed to handle conflict of interests to enhance their validity and acceptance. The suggested framework and indicator testing protocol may be useful in assessing the applicability of indicators for new medicines and may be adapted to healthcare settings worldwide. The suggestions build on existing literature to create a field testing methodology that can be used to produce country-specific quality indicators for new medicines as well as a cross international approach to facilitate access to new medicines

    Stress ocupacional e alteração do Estatuto da Carreira Docente português

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    Este estudo foi realizado com 1162 professores, tendo como objetivo analisar a experiência de stress e a síndrome de “burnout”, antes a após a alteração do Estatuto da Carreira Docente em Portugal. Assim, foram efetuadas duas avaliações em momentos temporais distintos, assumindo-se um plano transversal de recolha de dados (2004/2005, n=689 e 2008/2009, n=473). O protocolo de avaliação incluiu medidas de fontes de stress (Questionário de Stress nos Professores, Gomes, Silva, Mourisco, Mota, & Montenegro, 2006) e de “burnout” (Inventário de “Burnout” de Maslach – Versão para Professores, Maslach, Jackson, & Leiter, 1996; Maslach, Jackson, & Schwab, 1996, Adaptação de Gomes et al., 2006). Os resultados indicaram que a experiência de stress e de “burnout” aumentou entre as duas avaliações, verificando-se em 2008/2009 aumentos em áreas relacionadas com as pressões de tempo/excesso de trabalho e com o trabalho burocrático/administrativo e, inversamente, diminuições em áreas relacionadas com as diferentes capacidades e motivações dos alunos. Quanto à predição da síndrome de “burnout”, não se verificaram alterações substanciais nas variáveis preditoras nos dois momentos. Em síntese, os resultados indicaram aumentos nas exigências profissionais dos professores, mas não se pode afirmar que tal se deva às alterações do Estatuto da Carreira Docente uma vez que não observámos alterações no stress associado à carreira docente.(undefined

    Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

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    In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field

    Le rôle de l'enseignant dans l'innovation en éducation

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    Teacher role in educational innovation. - To contribute to an endeavour to change, we must understand the subjective world of teachers i.e. : analyse the process by which they make decisions and which seems to influence their reactions to change proposals, the evolution of their perceptions of innovation, their feelings, their competency and the importance of their share in innovation.L'enseignant joue un rôle central dans la transformation de l'éducation et l'amélioration au niveau de l'école. Tous ceux qui veulent collaborer à toute tentative de changement doivent comprendre le monde subjectif de l'enseignant Alors, il est nécessaire d'analyser le processus par lequel les enseignants prennent des décisions et qui semble influencer la réaction des enseignants envers les propositions de changement. Il est aussi important de prendre en considération le fait que les individus associés au changement passent par des étapes dans leurs perceptions de l'innovation et les sentiments qu'ils éprouvent à ce sujet, ainsi que dans leur compétence à s'en servir. Dans ce cadre on doit aussi essayer de comprendre la signification d'une formation continuée « centrée sur la pratique» et l'importance d'une participation des enseignants à l'innovation dans l'éducation. A la fin de cet article, quelques répercussions pratiques sont présentées.Vandenberghe Roland. Le rôle de l'enseignant dans l'innovation en éducation. In: Revue française de pédagogie, volume 75, 1986. pp. 17-26

    Creative management of a school

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    A teacher is a teacher is a teacher is a...: Teachers' professional development from a biographical perspective

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    The main aim of this project was to understand teachers' professional development by reconstructing their career experiences. The study examined the ways in which 10 experienced primary school teachers from 4 different Flemish schools experienced their careers, focusing on the personal perception and the subjective meaning of these experiences. Data were analyzed in two steps: (1) vertical analysis, which imposed a fixed structure to each teacher's data concerning formal career, professional biography, professional self, and subjective educational theory; and (2) horizontal analysis, which identified commonalities, differences, and patterns among the data from all respondents. The analysis examined teachers' self-image, self-esteem, job motivation, task perception, and future perspective. Recurring themes included teachers' perceived vulnerability and their need to cope with the limitations of their impact on pupils' results. The paper concludes that the study showed the usefulness of the biographical perspective for a better understanding of why teachers act the way they do. However, teachers' stimulated reflection on their career and personal development did not automatically change or improve their teaching practice. (Contains 51 references.) (JDD)status: publishe
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