On the relationship of magnetocrystalline anisotropy and stoichiometry in epitaxial L1(0) CoPt (001) and FePt (001) thin films

Two series of epitaxial CoPt and FePt films, with nominal thicknesses of 42 or 50 nm, were prepared by sputtering onto single-crystal MgO(001) substrates in order to investigate the chemical ordering and the resultant magnetic properties as a function of alloy composition. In the first series, the film composition was kept constant, while the substrate temperature was increased from 144 to 704 degrees C. In the second series the substrate temperature was kept constant at 704 degrees C for CoPt and 620 degrees C for FePt, while the alloy stoichiometry was varied in the nominal range of 40-60-at. % Co(Fe). Film compositions and thicknesses were measured via Rutherford backscattering spectrometry. The lattice and long-range order parameter for the L1(0) phase were obtained for both sets of films using x-ray diffraction. The room-temperature magnetocrystalline anisotropy constants were determined for a subset of the films using torque magnetometry. The order parameter was found to increase with increasing temperature, with ordering occurring more readily in FePt when compared with CoPt. A perpendicular anisotropy developed in CoPt for substrate temperatures above 534 degrees C and in FePt above 321 degrees C. The structure and width of the magnetic domains in CoPt and FePt, as seen by magnetic force microscopy, also demonstrated an increase in magnetic anisotropy with increasing temperature. For the films deposited at the highest temperatures (704 degrees C for CoPt and 620 degrees C for FePt), the order parameter reached a maximum near the equiatomic composition, whereas the magnetocrystalline anisotropy increased as the concentration of Co or Fe was increased from below to slightly above the equiatomic composition. It is concluded that nonstoichiometric L1(0) CoPt and FePt, with a slight excess of Co or Fe, are preferable for applications requiring the highest anisotropies

Barriers to Infectious Disease Care among Lesbians1

Despite the considerable number of women in the United States who identify as lesbian, few data exist that address lesbians' health needs. The Institute of Medicine emphasized that data on sexually transmitted infections, Pap smear screening, and cervical dysplasia among lesbians were needed to guide clinical practice, policy development, and patient education. Use of surveillance data for this purpose is limited because risk classifications exclude same-gender sex among women or subsume it under behavior considered as higher risk. However, sexual transmission of human papillomavirus, HIV, Treponema pallidum, and Trichomonas vaginalis between women has been reported. Data indicate that lesbians receive routine Pap smear screening less frequently than is optimal. Moreover, lesbians commonly report previous pregnancy, induced abortion, and hormonal contraceptive use. Education of lesbians and their care providers should counter assumptions that sex between women confers no risk for transmission of sexually transmitted infections, and lesbians should receive Pap smears according to current guidelines

Simplifying Consent for HIV Testing Is Associated with an Increase in HIV Testing and Case Detection in Highest Risk Groups, San Francisco January 2003–June 2007

Populations at highest risk for HIV infection face multiple barriers to HIV testing. To facilitate HIV testing procedures, the San Francisco General Hospital Medical Center eliminated required written patient consent for HIV testing in its medical settings in May 2006. To describe the change in HIV testing rates in different hospital settings and populations after the change in HIV testing policy in the SFDH medical center, we performed an observational study using interrupted time series analysis.Data from all patients aged 18 years and older seen from January 2003 through June 2007 at the San Francisco Department of Public Health (SFDPH) medical care system were included in the analysis. The monthly HIV testing rate per 1000 had patient-visits was calculated for the overall population and stratified by hospital setting, age, sex, race/ethnicity, homelessness status, insurance status and primary language.By June 2007, the average monthly rate of HIV tests per 1000 patient-visits increased 4.38 (CI, 2.17-6.60, p<0.001) over the number predicted if the policy change had not occurred (representing a 44% increase). The monthly average number of new positive HIV tests increased from 8.9 (CI, 6.3-11.5) to 14.9 (CI, 10.6-19.2, p<0.001), representing a 67% increase. Although increases in HIV testing were seen in all populations, populations at highest risk for HIV infection, particularly men, the homeless, and the uninsured experienced the highest increases in monthly HIV testing rates after the policy change.The elimination of the requirement for written consent in May 2006 was associated with a significant and sustained increase in HIV testing rates and HIV case detection in the SFDPH medical center. Populations facing the higher barriers to HIV testing had the highest increases in HIV testing rates and case detection in response to the policy change

Knowledge of Chlamydia trachomatis among men and women approached to participate in community-based screening, Scotland, UK

Background: Poor awareness and knowledge of Chlamydia trachomatis could be a barrier to uptake of screening. This study aimed to determine the level of awareness and knowledge of chlamydia among young people who were being approached in a variety of community settings and offered opportunistic screening.Methods: Men and women aged 16-24 years were approached in education, health and fitness, and workplace settings and invited to complete a self-administered questionnaire then provide a urine sample for chlamydia testing. Follow-up semi-structured interviews with 24 respondents were carried out after test results were received.Results: 363 questionnaires were completed (43.5% from men). Whilst awareness of chlamydia was high, knowledge decreased as questions became increasingly focussed so that around half of respondents were unaware of the asymptomatic nature of chlamydia infections. Men's knowledge of symptoms was consistently lower than women's, with most men failing to identify unusual discharge as a symptom in men (men 58.3%, female 45.8%, p = 0.019); fewer men knew unusual discharge was a symptom among women (men 65.3% female 21.4%, p < 0.001). The asymptomatic nature of the infection resonated with respondents and was the commonest piece of information they picked up from their participation in the study.Conclusions: Despite scientific gains in understanding chlamydia infection, public understanding remains limited. Greater efforts are required to translate scientific evidence to the public. An improvement in knowledge may maximise gains from interventions to improve detection

An Integral Analysis of Bahamian Adolescents’ Reflections on Their Future Lives After They Complete High School

Adolescents who are nearing the end of their experience in high school are faced with many opportunities and challenges, which may direct their future path towards higher education and career development. The future orientation among Bahamian adolescents was looked at from an integral lens, which guided this research. The beliefs and goals Bahamian adolescents had for their future were explored and included present actions and plans students proposed to realize these goals. Further, the expectations adolescents perceived others had for them and the perceptions they held for themselves also guided this research. Finally, outside influences and systems that impact adolescents’ implementation and realization of their goals were identified. The use of integral methodological pluralism, supported by mixed methods research, gathered phenomenological, hermeneutical and empirical data from school and community members involved in a private high school in the Commonwealth of The Bahamas. Studies on future orientation with adolescents in other countries provided a comparison for and offered additional insight into the phenomenon of college and career readiness