314 research outputs found

    Quantum Theory contents insertion in High School curricula

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    A inovação científica e tecnológica do século XX foi esmagadora. Contudo, a nossa experiência docente permite-nos afirmar que as aprendizagens na escola secundária estão longe de acompanhar a evolução que se verifica na sociedade atual. No entanto, já estão a ser incluídos alguns conteúdos de Física Moderna nos currículos oficiais de vários países, parecendo evidenciar uma preocupação em atualizar a preparação dos jovens para o mundo que os rodeia. Neste artigo relatamos um estudo que fizemos acerca dos currículos de Física de alguns países, sobretudo no que diz respeito à Teoria Quântica, a grande invenção do século XX, tentando identificar os conteúdos selecionados e a maneira como estes se integram nas orientações curriculares gerais.In the XXth century, scientific and technological innovation has been overwhelming. Our teaching profession lead us to believe that studies in High Schools do not follow the evolution of ideas that characterizes our modern society. However, some contents of Modern Physics are already included in the official curricula of several countries, which seem to be worried about the improvement of today’s youth training. In this paper we report a study made about Physics’ curricula in several countries, emphasizing Quantum Theory issues, the biggest invention of the XXth century, trying to identify the selected subjects selected and the way they fit into general curricula orientations

    The Randomized Shortened Dental Arch Study: Tooth Loss

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    The evidence concerning the management of shortened dental arch (SDA) cases is sparse. This multi-center study was aimed at generating data on outcomes and survival rates for two common treatments, removable dental prostheses (RDP) for molar replacement or no replacement (SDA). The hypothesis was that the treatments lead to different incidences of tooth loss. We included 215 patients with complete molar loss in one jaw. Molars were either replaced by RDP or not replaced, according to the SDA concept. First tooth loss after treatment was the primary outcome measure. This event occurred in 13 patients in the RDP group and nine patients in the SDA group. The respective Kaplan-Meier survival rates at 38 months were 0.83 (95% CI: 0.74-0.91) in the RDP group and 0.86 (95% CI: 0.78-0.95) in the SDA group, the difference being non-significant

    Biomarkers in respiratory diseases

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    The scientific evidence concerning prosthodontic care for the shortened dental arch (SDA) is sparse. This randomized multicenter study aimed to compare two common treatment options: removable partial dental prostheses (RPDPs) for molar replacement vs. no replacement (SDA). One of the hypotheses was that the follow-up treatment differs between patients with RPDPs and patients with SDAs during the 5-year follow-up period. Two hundred and fifteen patients with complete molar loss in one jaw were included in the study. Molars were either replaced by RPDPs or not replaced according to the SDA concept. A mean number of 4.2 (RPDP) and 2.8 (SDA) treatments for biological or technical reasons occurred during the 5-year observation time per patient. Concerning the biological aspect, no significant differences between the groups could be shown, whereas treatment arising from technical reasons was significantly more frequent for the RPDP group. When the severity of treatment was analyzed, a change over time was evident. When, at baseline, only follow-up treatment with minimal effort is required, over time there is a continuous increase to moderate and extensive effort observed for both groups ( Controlled-trials.com number ISRCTN97265367). </jats:p

    Work Group 3 Position Paper: Teacher Education and Teaching/Learning Quantum Physics

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    In this article the discussion of Working Group 3 during the GIREP online seminar 2020 on teaching and learning quantum physics in teacher education is summarized. Conclusions are drawn and research desiderata formulated

    Design and evaluation of a questionnaire to assess learners' understanding of quantum measurement in different two-state contexts: The context matters

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    The teaching and learning of quantum physics has recently become a topic of increasing interest in physics education research. In particular, the study of two-state systems is gaining importance as a means of teaching quantum physics at various educational levels. Meanwhile, a number of approaches have been developed that are also suitable for high school students. It can be assumed that the different approaches have different degrees of effectiveness in teaching central quantum concepts. However, suitable evaluation instruments to test this are still lacking. Therefore, as a first step, a short questionnaire on quantum measurement, suitable for both research and classroom use, was developed in several steps. First, a questionnaire with open and closed items was created and piloted with a total of N=120 learners. The responses were evaluated qualitatively using a comprehensive coding manual, which provided insights into learners' conceptions. These results led to the development of an eight-item questionnaire that could be adapted to different teaching approaches. This questionnaire was subjected to expert review and, finally, successfully tested for its psychometric properties with a sample of N=201 learners. Overall, our results provide initial empirical evidence that context (i.e., which two-state approach is used) does matter for student learning, but in general, two-state approaches appear to be particularly conducive to learning quantum concepts (specified in this article for quantum measurement) compared to traditional instruction

    The role of mathematics for physics teaching and understanding

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    That mathematics is the “language of physics” implies that both areas are deeply interconnected, such that often no separation between “pure” mathematics and “pure” physics is possible. To clarify their interplay a technical and a structural role of mathematics can be distinguished. A thorough understanding of this twofold role in physics is also important for shaping physics education especially with respect to teaching the nature of physics. Herewith the teachers and their pedagogical content knowledge play an important role. Therefore we develop a model of PCK concerning the interplay of mathematics and physics in order to provide a theoretical framework for the views and teaching strategies of teachers. In an exploratory study four teachers from Germany and four teachers from Israel have been interviewed concerning their views and its transfer to teaching physics. Here we describe the results from Germany. Besides general views and knowledge held by all or nearly all teachers we also observe specific individual focus depending on the teachers’ background and experiences. The results fit well into the derived model of PCK

    Fattori che ispirano studenti delle scuole superiori di 14 nazioni europee allo studio della fisica

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    Nell'ambito del progetto Europeo Hope, che ha coinvolto 72 partner Europei, \ue8 stata svolta un'indagine sui fattori che ispirano studenti di scuola superiore interessati alla fisica a scegliere una laurea in fisica. \uc8 stato somministrato un questionario con domande aperte e con valutazione su scala a 5 livelli. L'indagine ha riguardato 1475 studenti di 14 nazioni partecipanti a specifici eventi (olimpiadi, scuole estive, laboratori). Metodi diversi di analisi evidenziano che la scelta di una laurea in fisica \ue8 spesso esito di un interesse precoce sostenuto nel corso degli anni

    Bisphosphonate inhibitors of squalene synthase protect cells against cholesterol‐dependent cytolysins

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    Certain species of pathogenic bacteria damage tissues by secreting cholesterol‐dependent cytolysins, which form pores in the plasma membranes of animal cells. However, reducing cholesterol protects cells against these cytolysins. As the first committed step of cholesterol biosynthesis is catalyzed by squalene synthase, we explored whether inhibiting this enzyme protected cells against cholesterol‐dependent cytolysins. We first synthesized 22 different nitrogen‐containing bisphosphonate molecules that were designed to inhibit squalene synthase. Squalene synthase inhibition was quantified using a cell‐free enzyme assay, and validated by computer modeling of bisphosphonate molecules binding to squalene synthase. The bisphosphonates were then screened for their ability to protect HeLa cells against the damage caused by the cholesterol‐dependent cytolysin, pyolysin. The most effective bisphosphonate reduced pyolysin‐induced leakage of lactate dehydrogenase into cell supernatants by >80%, and reduced pyolysin‐induced cytolysis from >75% to <25%. In addition, this bisphosphonate reduced pyolysin‐induced leakage of potassium from cells, limited changes in the cytoskeleton, prevented mitogen‐activated protein kinases cell stress responses, and reduced cellular cholesterol. The bisphosphonate also protected cells against another cholesterol‐dependent cytolysin, streptolysin O, and protected lung epithelial cells and primary dermal fibroblasts against cytolysis. Our findings imply that treatment with bisphosphonates that inhibit squalene synthase might help protect tissues against pathogenic bacteria that secrete cholesterol‐dependent cytolysins
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