107 research outputs found

    Intrinsic and Synthetic Stable Isotope Marking of Tsetse Flies

    Get PDF
    The sterile insect technique has been successfully used to eliminate tsetse populations in a number of programs. Program monitoring in the field relies on the ability to accurately differentiate released sterile insects from wild insects so that estimates can be made of the ratio of sterile males to wild males. Typically, released flies are marked with a dye, which is not always reliable. The difference in isotopic signatures between wild and factory-reared populations could be a reliable and intrinsic secondary marker to complement existing marking methods. Isotopic signatures are natural differences in stable isotope composition of organisms due to discrimination against the heavier isotopes during some biological processes. As the isotopic signature of an organism is mainly dependent on what it eats; by feeding factory-reared flies isotopically different diets to those of the wild population it is possible to intrinsically mark the flies. To test this approach unlabeled samples of Glossina pallidipes (Austen) (Diptera: Glossinidae) from a mass rearing facility and wild populations were analyzed to determine whether there were any natural differences in signatures that could be used as markers. In addition experiments were conducted in which the blood diet was supplemented with isotopically enriched compounds and the persistence of the marker in the offspring determined. There were distinct natural isotopic differences between factory reared and wild tsetse populations that could be reliably used as population markers. It was also possible to rear artificially isotopically labeled flies using simple technology and these flies were clearly distinguishable from wild populations with greater than 95% certainty after 85 days of “release”. These techniques could be readily adopted for use in SIT programs as complimentary marking techniques

    Is U.S. health care an appropriate system? A strategic perspective from systems science

    Get PDF
    <p>Abstract</p> <p>Context</p> <p>Systems science provides organizational principles supported by biologic findings that can be applied to any organization; any incongruence indicates an incomplete or an already failing system. U.S. health care is commonly referred to as a system that consumes an ever- increasing percentage of the gross domestic product and delivers seemingly diminishing value.</p> <p>Objective</p> <p>To perform a comparative study of U.S. health care with the principles of systems science and, if feasible, propose solutions.</p> <p>Design</p> <p>General systems theory provides the theoretical foundation for this observational research.</p> <p>Main Outcome Measures</p> <p>A degree of compliance of U.S. health care with systems principles and its space-time functional location within the dynamic systems model.</p> <p>Results of comparative analysis</p> <p>U.S. health care is an incomplete system further threatened by the fact that it functions in the zone of chaos within the dynamic systems model.</p> <p>Conclusion</p> <p>Complying with systems science principles and the congruence of pertinent cycles, U.S. health care would likely dramatically improve its value creation for all of society as well as its resiliency and long-term sustainability.</p> <p>Immediate corrective steps could be taken: Prioritize and incentivize <it>health </it>over <it>care</it>; restore fiscal soundness by combining health and life insurance for the benefit of the insured and the payer; rebalance horizontal/providers and vertical/government hierarchies.</p

    Family physicians\u27 professional identity formation: a study protocol to explore impression management processes in institutional academic contexts.

    Get PDF
    BACKGROUND: Despite significant differences in terms of medical training and health care context, the phenomenon of medical students\u27 declining interest in family medicine has been well documented in North America and in many other developed countries as well. As part of a research program on family physicians\u27 professional identity formation initiated in 2007, the purpose of the present investigation is to examine in-depth how family physicians construct their professional image in academic contexts; in other words, this study will allow us to identify and understand the processes whereby family physicians with an academic appointment seek to control the ideas others form about them as a professional group, i.e. impression management. METHODS/DESIGN: The methodology consists of a multiple case study embedded in the perspective of institutional theory. Four international cases from Canada, France, Ireland and Spain will be conducted; the \u22case\u22 is the medical school. Four levels of analysis will be considered: individual family physicians, interpersonal relationships, family physician professional group, and organization (medical school). Individual interviews and focus groups with academic family physicians will constitute the main technique for data generation, which will be complemented with a variety of documentary sources. Discourse techniques, more particularly rhetorical analysis, will be used to analyze the data gathered. Within- and cross-case analysis will then be performed. DISCUSSION: This empirical study is strongly grounded in theory and will contribute to the scant body of literature on family physicians\u27 professional identity formation processes in medical schools. Findings will potentially have important implications for the practice of family medicine, medical education and health and educational policies

    The Chlamydia psittaci Genome: A Comparative Analysis of Intracellular Pathogens

    Get PDF
    Chlamydiaceae are a family of obligate intracellular pathogens causing a wide range of diseases in animals and humans, and facing unique evolutionary constraints not encountered by free-living prokaryotes. To investigate genomic aspects of infection, virulence and host preference we have sequenced Chlamydia psittaci, the pathogenic agent of ornithosis.A comparison of the genome of the avian Chlamydia psittaci isolate 6BC with the genomes of other chlamydial species, C. trachomatis, C. muridarum, C. pneumoniae, C. abortus, C. felis and C. caviae, revealed a high level of sequence conservation and synteny across taxa, with the major exception of the human pathogen C. trachomatis. Important differences manifest in the polymorphic membrane protein family specific for the Chlamydiae and in the highly variable chlamydial plasticity zone. We identified a number of psittaci-specific polymorphic membrane proteins of the G family that may be related to differences in host-range and/or virulence as compared to closely related Chlamydiaceae. We calculated non-synonymous to synonymous substitution rate ratios for pairs of orthologous genes to identify putative targets of adaptive evolution and predicted type III secreted effector proteins.This study is the first detailed analysis of the Chlamydia psittaci genome sequence. It provides insights in the genome architecture of C. psittaci and proposes a number of novel candidate genes mostly of yet unknown function that may be important for pathogen-host interactions

    Measuring Spirituality as a Universal Human Experience: A Review of Spirituality Questionnaires

    Get PDF
    Spirituality is an important theme in health research, since a spiritual orientation can help people to cope with the consequences of a serious disease. Knowledge on the role of spirituality is, however, limited, as most research is based on measures of religiosity rather than spirituality. A questionnaire that transcends specific beliefs is a prerequisite for quantifying the importance of spirituality among people who adhere to a religion or none at all. In this review, we discuss ten questionnaires that address spirituality as a universal human experience. Questionnaires are evaluated with regard to psychometric properties, item formulation and confusion with well-being and distress. Although none of the questionnaires fulfilled all the criteria, the multidimensional Spiritual Well-Being Questionnaire is promising

    The macrophage in HIV-1 infection: From activation to deactivation?

    Get PDF
    Macrophages play a crucial role in innate and adaptative immunity in response to microorganisms and are an important cellular target during HIV-1 infection. Recently, the heterogeneity of the macrophage population has been highlighted. Classically activated or type 1 macrophages (M1) induced in particular by IFN-γ display a pro-inflammatory profile. The alternatively activated or type 2 macrophages (M2) induced by Th-2 cytokines, such as IL-4 and IL-13 express anti-inflammatory and tissue repair properties. Finally IL-10 has been described as the prototypic cytokine involved in the deactivation of macrophages (dM). Since the capacity of macrophages to support productive HIV-1 infection is known to be modulated by cytokines, this review shows how modulation of macrophage activation by cytokines impacts the capacity to support productive HIV-1 infection. Based on the activation status of macrophages we propose a model starting with M1 classically activated macrophages with accelerated formation of viral reservoirs in a context of Th1 and proinflammatory cytokines. Then IL-4/IL-13 alternatively activated M2 macrophages will enter into the game that will stop the expansion of the HIV-1 reservoir. Finally IL-10 deactivation of macrophages will lead to immune failure observed at the very late stages of the HIV-1 disease

    TMJ response to mandibular advancement surgery: an overview of risk factors

    Full text link

    Heavy Metals in Some River and Bay Sediments near Swansea

    No full text
    corecore