530 research outputs found

    Structure And Properties Of Silver Borate Glasses

    Get PDF
    Clear glasses form in the system Ag2O‐B2O3 up to about 35 mol% (65 wt%) Ag2O. Infrared absorption, thermal expansion, and density data indicated an analogy to the Na2O‐B2O3 system. Pentaborate‐triborate group pairs appear to be formed on addition of Ag2O to B2O3 up to 20 mol% Ag2O and diborate groups from 20 to 33 mol% Ag2O. This interpretation is supported by the comparison of the infrared absorption spectra of quenched and crystallized glasses. One crystallization product, Ag2O‐4B2O3, was identified previously. A new compound starts to appear at 28 mol% Ag2O. The theory that silver is generally present as a network modifier like sodium was substantiated by the comparison of the molar volume of sodium and silver borate glasses. Above 27 mol% Ag2O some atomic silver is assumed to be present; below 15 mol%, exploratory studies indicate a two‐phase structure within an immiscibility gap. A low‐temperature internal friction peak in the glasses up to 28 mol% Ag2O corresponds to the alkali peak in other glasses; a high temperature peak appearing in the 34 mol% Ag2O glass is associated with the appearance of nonbridging oxygen in the system. Copyright © 1971, Wiley Blackwell. All rights reserve

    A national clinician–educator program: a model of an effective community of practice

    Get PDF
    Background: The increasing complexity of medical training often requires faculty members with educational expertise to address issues of curriculum design, instructional methods, assessment, program evaluation, faculty development, and educational scholarship, among others. Discussion: In 2007, The Royal College of Physicians & Surgeons of Canada responded to this need by establishing the first national clinician–educator program. We define a clinician–educator and describe the development of the program. Adopting a construct from the business community, we use a community of practice framework to describe the benefits (with examples) of this program and challenges in developing it. The benefits of the clinician–educator program include: improved educational problem solving, recognition of educational needs and development of new projects, enhanced personal educational expertise, maintenance of professional satisfaction and retention of group members, a positive influence within the Royal College, and a positive influence within other Canadian academic institutions. Summary: Our described experience of a social reorganization – a community of practice – suggests that the organizational and educational benefits of a national clinician–educator program are not theoretical, but real

    Wikis, blogs and podcasts: a new generation of Web-based tools for virtual collaborative clinical practice and education

    Get PDF
    BACKGROUND: We have witnessed a rapid increase in the use of Web-based 'collaborationware' in recent years. These Web 2.0 applications, particularly wikis, blogs and podcasts, have been increasingly adopted by many online health-related professional and educational services. Because of their ease of use and rapidity of deployment, they offer the opportunity for powerful information sharing and ease of collaboration. Wikis are Web sites that can be edited by anyone who has access to them. The word 'blog' is a contraction of 'Web Log' – an online Web journal that can offer a resource rich multimedia environment. Podcasts are repositories of audio and video materials that can be "pushed" to subscribers, even without user intervention. These audio and video files can be downloaded to portable media players that can be taken anywhere, providing the potential for "anytime, anywhere" learning experiences (mobile learning). DISCUSSION: Wikis, blogs and podcasts are all relatively easy to use, which partly accounts for their proliferation. The fact that there are many free and Open Source versions of these tools may also be responsible for their explosive growth. Thus it would be relatively easy to implement any or all within a Health Professions' Educational Environment. Paradoxically, some of their disadvantages also relate to their openness and ease of use. With virtually anybody able to alter, edit or otherwise contribute to the collaborative Web pages, it can be problematic to gauge the reliability and accuracy of such resources. While arguably, the very process of collaboration leads to a Darwinian type 'survival of the fittest' content within a Web page, the veracity of these resources can be assured through careful monitoring, moderation, and operation of the collaborationware in a closed and secure digital environment. Empirical research is still needed to build our pedagogic evidence base about the different aspects of these tools in the context of medical/health education. SUMMARY AND CONCLUSION: If effectively deployed, wikis, blogs and podcasts could offer a way to enhance students', clinicians' and patients' learning experiences, and deepen levels of learners' engagement and collaboration within digital learning environments. Therefore, research should be conducted to determine the best ways to integrate these tools into existing e-Learning programmes for students, health professionals and patients, taking into account the different, but also overlapping, needs of these three audience classes and the opportunities of virtual collaboration between them. Of particular importance is research into novel integrative applications, to serve as the "glue" to bind the different forms of Web-based collaborationware synergistically in order to provide a coherent wholesome learning experience

    “A good little tool to get to know yourself a bit better”: a qualitative study on users’ experiences of app-supported menstrual tracking in Europe

    Get PDF
    Background: Menstrual apps facilitate observation and analysis of menstrual cycles and associated factors through the collection and interpretation of data entered by users. As a subgroup of health-related apps, menstrual apps form part of one of the most dynamic and rapidly growing developments in biomedicine and health care. However, despite their popularity, qualitative research on how people engaging in period-tracking use and experience these apps remains scarce. Results: An inductive content analysis was performed and eight characteristics of app-supported menstrual tracking were identified: 1) tracking menstrual cycle dates and regularities, 2) preparing for upcoming periods, 3) getting to know menstrual cycles and bodies, 4) verifying menstrual experiences and sensations, 5) informing healthcare professionals, 6) tracking health, 7) contraception and seeking pregnancy, and 8) changes in tracking. Our study finds that period-tracking via apps has the potential to be an empowering practice as it helps users to be more aware of their menstrual cycles and health and to gain new knowledge. However, we also show that menstrual tracking can have negative consequences as it leads to distress in some cases, to privacy issues, and the work it requires can result in cessation. Finally, we present practical implications for healthcare providers and app developers. Conclusions: This qualitative study gives insight into users’ practices and experiences of app-supported menstrual tracking. The results provide information for researchers, health care providers and app designers about the implications of app-supported period-tracking and describe opportunities for patient-doctor interactions as well as for further development of menstrual apps.This research has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie SkƂodowska-Curie grant agreement No 675378

    Circadian Phase Resetting via Single and Multiple Control Targets

    Get PDF
    Circadian entrainment is necessary for rhythmic physiological functions to be appropriately timed over the 24-hour day. Disruption of circadian rhythms has been associated with sleep and neuro-behavioral impairments as well as cancer. To date, light is widely accepted to be the most powerful circadian synchronizer, motivating its use as a key control input for phase resetting. Through sensitivity analysis, we identify additional control targets whose individual and simultaneous manipulation (via a model predictive control algorithm) out-perform the open-loop light-based phase recovery dynamics by nearly 3-fold. We further demonstrate the robustness of phase resetting by synchronizing short- and long-period mutant phenotypes to the 24-hour environment; the control algorithm is robust in the presence of model mismatch. These studies prove the efficacy and immediate application of model predictive control in experimental studies and medicine. In particular, maintaining proper circadian regulation may significantly decrease the chance of acquiring chronic illness

    Tropheryma whipplei, the Whipple's disease bacillus, induces macrophage apoptosis through the extrinsic pathway

    Get PDF
    Tropheryma whipplei, the etiological agent of Whipple's disease, is an intracellular bacterium that infects macrophages. We previously showed that infection of macrophages results in M2 polarization associated with induction of apoptosis and interleukin (IL)-16 secretion. In patients with Whipple's disease, circulating levels of apoptotic markers and IL-16 are increased and correlate with the activity of the disease. To gain insight into the understanding of the pathophysiology of this rare disease, we examined the molecular pathways involved in T. whipplei-induced apoptosis of human macrophages. Our data showed that apoptosis induction depended on bacterial viability and inhibition of bacterial protein synthesis reduced the apoptotic program elicited by T. whipplei. Induction of apoptosis was also associated with a massive degradation of both pro- and anti-apoptotic mediators. Caspase-specific inhibition experiments revealed that initiator caspases 8 and 10 were required for apoptosis, in contrast to caspases 2 and 9, in spite of cytochrome-c release from mitochondria. Finally, the effector caspases 3 and 6 were mandatory for apoptosis induction. Collectively, these data suggest that T. whipplei induces apoptosis through the extrinsic pathway and that, beside M2 polarization of macrophages, apoptosis induction contributes to bacterial replication and represents a virulence trait of this intracellular pathogen

    Wild food plants of popular use in Sicily

    Get PDF
    In the present work the authors report the result of their food ethnobotanical researches, which have been carried out in Sicily during the last thirty years. Data concerning 188 wild species used in the traditional Sicilian cuisine are reported. The authors underline those species that are partially or completely unknown for their culinary use and they illustrate other species that local inhabitants suggested in the prevention or treatment of symptomatologies caused by a refined diet, poor in vegetables. These data want to contribute to avoid the loss of traditional knowledge on uses and recipes concerning wild food botanicals, and to encourage further studies for those species that have not yet been sufficiently researched in their food chemical and nutritional profile. These studies may also suggest new applications for a few botanicals in medico-nutritional fields. The work includes also a short review of the seaweeds and mushrooms traditionally gathered and consumed in Sicily
    • 

    corecore