Thermopower of the Correlated Narrow Gap Semiconductor FeSi and Comparison to RuSi

Iron based narrow gap semiconductors such as FeSi, FeSb2, or FeGa3 have received a lot of attention because they exhibit a large thermopower, as well as striking similarities to heavy fermion Kondo insulators. Many proposals have been advanced, however, lacking quantitative methodologies applied to this problem, a consensus remained elusive to date. Here, we employ realistic many-body calculations to elucidate the impact of electronic correlation effects on FeSi. Our methodology accounts for all substantial anomalies observed in FeSi: the metallization, the lack of conservation of spectral weight in optical spectroscopy, and the Curie susceptibility. In particular we find a very good agreement for the anomalous thermoelectric power. Validated by this congruence with experiment, we further discuss a new physical picture of the microscopic nature of the insulator-to-metal crossover. Indeed, we find the suppression of the Seebeck coefficient to be driven by correlation induced incoherence. Finally, we compare FeSi to its iso-structural and iso-electronic homologue RuSi, and predict that partially substituted Fe(1-x)Ru(x)Si will exhibit an increased thermopower at intermediate temperatures.Comment: 14 pages. Proceedings of the Hvar 2011 Workshop on 'New materials for thermoelectric applications: theory and experiment

Lipidomic analysis of plasma samples from women with polycystic ovary syndrome

Abstract Polycystic ovary syndrome (PCOS) is a common disorder affecting between 5 and 18 % of females of reproductive age and can be diagnosed based on a combination of clinical, ultrasound and biochemical features, none of which on its own is diagnostic. A lipidomic approach using liquid chromatography coupled with accurate mass high-resolution mass-spectrometry (LCHRMS) was used to investigate if there were any differences in plasma lipidomic profiles in women with PCOS compared with control women at different stages of menstrual cycle. Plasma samples from 40 women with PCOS and 40 controls aged between 18 and 40 years were analysed in combination with multivariate statistical analyses. Multivariate data analysis (LASSO regression and OPLSDA) of the sample lipidomics datasets showed a weak prediction model for PCOS versus control samples from the follicular and mid-cycle phases of the menstrual cycle, but a stronger model (specificity 85 % and sensitivity 95 %) for PCOS versus the luteal phase menstrual cycle controls. The PCOS vs luteal phase model showed increased levels of plasma triglycerides and sphingomyelins and decreased levels of lysophosphatidylcholines and phosphatidylethanolamines in PCOS women compared with controls. Lipid biomarkers of PCOS were tentatively identified which may be useful in distinguishing PCOS from controls especially when performed during the menstrual cycle luteal phase

Protecting the health of health care workers : a global perspective

"Fundamental elements for the provision, organization, and establishment of occupational health and safety (OHS) services for health care workers in rural/remote areas and developing countries include adequate resources, a strong safety culture, recognition of occupational health professionals, collaborative practice, and capability for communication and local risk analysis. First, however, assessment of existing OHS services is required. Adaptable needs assessment tools designed for use by local health care workers should allow progression from analysis to action. Essential elements of these tools include utility, recognition of the surrounding political, health care, and physical environments, and clear definition of the roles and responsibilities of users to act upon findings and implement solutions. Securing adequate financial, physical, and human resources for occupational health and safety requires critical analysis of topics such as health care culture, political motivation, health care worker migration, and national and international financing. It is necessary to reshape attitudes towards valuing the health of health care workers. This includes acknowledging occupational health professional accreditation and educating health care students about OHS. It is also crucial to create awareness of workers' health among health care managers and administrators and to develop their knowledge and capability to support OHS. Resources such as the Pan American Health Organization's (PAHO) document "Workers' Health and Safety in the Health Sector: A Manual for Managers and Administrators" are valuable assets. Suggestions for collaborative practice include the formation and use of local OHS committees that involve decision makers, administrators, and health care workers. Communication strategies involve the free flow of information between policy makers, educators, employers, research laboratories, and health care workers. Mobile occupational health clinics and portable libraries are two examples of innovative methods of communication and information dissemination. Risk analyses allow occupational health practitioners to target local services to the most needed areas. Point prevalence surveys and workplace audit tools are effective methods to collect this data in remote and resource poor settings. Priorities for prevention of blood-borne and air-borne disease transmission include education and comprehensive protocols and guidelines. Adequate, up-to-date, and ongoing OHS education and training for health care workers is essential. Protocols and guidelines should direct practice and uphold internationally endorsed standards while being responsive to local realities and needs. Protocol and guideline development and implementation must also involve the multiple stakeholder groups such as infection control, public health, funders, administrators, and health care workers. Immunizations and adequate access to post exposure management are vital for secondary prevention. Information such as prevalence and incidence rates of diseases endemic to the local area, transmission patterns and trends, and population projections are necessary to make informed decisions about vaccination priorities. Adequate institutional support for post exposure prophylaxis and follow-up consultations is also vital to ensure the quality of appropriate care following workrelated injuries. " - NIOSHTIC-2Publication authors, contributors, and workshop participants -- Acknowledgements -- Abbreviations -- Workshop overview -- Introduction -- Section One: Organization and provision of occupational health services in health care -- Section Two: Establishing occupational health programs -- Section Three: Primary prevention for blood-borne and air-borne pathogens -- Section Four: Immunizations and post exposure follow-up -- Concluding remarks -- Appendix A: Workshop agendaRebman, R., (Ed.). Rodri\ucc?guez Guzma\ucc?n, J.; Dybka, L.; Watson, R.; Lavoie, M.; Yassi, A.; Gamage, B.; Pugh, S.; Lehtinen, S.; Tennassee, M.; Nophale, L.E. (2008)."This synthesis report stems from a one-day pre-conference workshop, "Occupational Health Services for Health Care Workers in Rural/Remote Areas and Developing Countries." The workshop was part of the International Commission on Occupational Health (ICOH) Conference on Health Care Worker Health / 2007 State-of-the-Art Conference (SOTAC) held from 26 to 28 October 2007 in Vancouver, Canada. For this conference, ICOH and the American College of Occupational and Environmental Medicine (ACOEM) joined together to share research and understanding on protecting the health of health care workers." - p. 1"February 2009."Also available via the World Wide Web as an Acrobat .pdf file (956.69 KB, 58 p.).Includes bibliographical references (p. 47-48)

Polycystic ovary syndrome

The document attached has been archived with permission from the editor of the Medical Journal of Australia. An external link to the publisher’s copy is included.Polycystic ovary syndrome (PCOS) affects 5-20% of women of reproductive age worldwide. The condition is characterized by hyperandrogenism, ovulatory dysfunction and polycystic ovarian morphology (PCOM) - with excessive androgen production by the ovaries being a key feature of PCOS. Metabolic dysfunction characterized by insulin resistance and compensatory hyperinsulinaemia is evident in the vast majority of affected individuals. PCOS increases the risk for type 2 diabetes mellitus, gestational diabetes and other pregnancy-related complications, venous thromboembolism, cerebrovascular and cardiovascular events and endometrial cancer. PCOS is a diagnosis of exclusion, based primarily on the presence of hyperandrogenism, ovulatory dysfunction and PCOM. Treatment should be tailored to the complaints and needs of the patient and involves targeting metabolic abnormalities through lifestyle changes, medication and potentially surgery for the prevention and management of excess weight, androgen suppression and/or blockade, endometrial protection, reproductive therapy and the detection and treatment of psychological features. This Primer summarizes the current state of knowledge regarding the epidemiology, mechanisms and pathophysiology, diagnosis, screening and prevention, management and future investigational directions of the disorder.Robert J Norman, Ruijin Wu and Marcin T Stankiewic