731 research outputs found

    Influence of a transverse static magnetic field on the magnetic hyperthermia properties and high-frequency hysteresis loops of ferromagnetic FeCo nanoparticles

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    The influence of a transverse static magnetic field on the magnetic hyperthermia properties is studied on a system of large-losses ferromagnetic FeCo nanoparticles. The simultaneous measurement of the high-frequency hysteresis loops and of the temperature rise provides an interesting insight into the losses and heating mechanisms. A static magnetic field of only 40 mT is enough to cancel the heating properties of the nanoparticles, a result reproduced using numerical simulations of hysteresis loops. These results cast doubt on the possibility to perform someday magnetic hyperthermia inside a magnetic resonance imaging setup.Comment: 6 pages, 3 figure

    Visually guided grasping to study teleprogrammation within the BAROCO testbed

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    This paper describes vision functionalities required in future orbital laboratories; in such systems, robots will be needed in order to execute the on-board scientific experiments or servicing and maintenance tasks under the remote control of ground operators. For this sake, ESA has proposed a robotic configuration called EMATS; a testbed has been developed by ESTEC in order to evaluate the potentialities of EMATS-like robot to execute scientific tasks in automatic mode. For the same context, CNES develops the BAROCO testbed to investigate remote control and teleprogrammation, in which high level primitives like 'Pick Object A' are provided as basic primitives. In nominal situations, the system has an a priori knowledge about the position of all objects. These positions are not very accurate, but this knowledge is sufficient in order to predict the position of the object which must be grasped, with respect to the manipulator frame. Vision is required in order to insure a correct grasping and to guarantee a good accuracy for the following operations. We describe our results about a visually guided grasping of static objects. It seems to be a very classical problem, and a lot of results are available. But, in many cases, it lacks a realistic evaluation of the accuracy, because such an evaluation requires tedious experiments. We propose several results about calibration of the experimental testbed, recognition algorithms required to locate a 3D polyhedral object, and the grasping itself

    Loss to Follow-Up After Pregnancy Among Sub-Saharan Africa-Born Women Living With Human Immunodeficiency Virus in England, Wales and Northern Ireland: Results From a Large National Cohort.

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    BACKGROUND: Little is known about retention in human immunodeficiency virus (HIV) care in HIV-positive women after pregnancy in the United Kingdom. We explored the association between loss to follow-up (LTFU) in the year after pregnancy, maternal place of birth and duration of UK residence, in HIV-positive women in England, Wales, and Northern Ireland. METHODS: We analyzed combined data from 2 national data sets: the National Study of HIV in Pregnancy and Childhood; and the Survey of Prevalent HIV Infections Diagnosed, including pregnancies in 2000 to 2009 in women with diagnosed HIV. Logistic regression models were fitted with robust standard errors to estimate adjusted odds ratios (AOR). RESULTS: Overall, 902 of 7211 (12.5%) women did not access HIV care in the year after pregnancy. Factors associated with LTFU included younger age, last CD4 in pregnancy of 350 cells/μL or greater and detectable HIV viral load at the end of pregnancy (all P < 0.001). On multivariable analysis, LTFU was more likely in sub-Saharan Africa-born (SSA-born) women than white UK-born women (AOR, 2.17; 95% confidence interval, 1.50-3.14; P < 0.001). The SSA-born women who had migrated to the UK during pregnancy were 3 times more likely than white UK-born women to be lost to follow-up (AOR, 3.19; 95% confidence interval, 1.94-3.23; P < 0.001). CONCLUSIONS: One in 8 HIV-positive women in England, Wales, and Northern Ireland did not return for HIV care in the year after pregnancy, with SSA-born women, especially those who migrated to the United Kingdom during pregnancy, at increased risk. Although emigration is a possible explanatory factor, disengagement from care may also play a role

    Primary care consultations and costs among HIV-positive individulas in UK primary care 1995-2005: a cohort study

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    Objectives: To investigate the role of primary care in the management of HIV and estimate primary care-associated costs at a time of rising prevalence. Methods: Retrospective cohort study between 1995 and 2005, using data from general practices contributing data to the UK General Practice Research Database. Patterns of consultation and morbidity and associated consultation costs were analysed among all practice-registered patients for whom HIV-positive status was recorded in the general practice record. Results: 348 practices yielded 5504 person-years (py) of follow-up for known HIV-positive patients, who consult in general practice frequently (4.2 consultations/py by men, 5.2 consultations/py by women, in 2005) for a range of conditions. Consultation rates declined in the late 1990s from 5.0 and 7.3 consultations/py in 1995 in men and women, respectively, converging to rates similar to the wider population. Costs of consultation (general practitioner and nurse, combined) reflect these changes, at £100.27 for male patients and £117.08 for female patients in 2005. Approximately one in six medications prescribed in primary care for HIV-positive individuals has the potential for major interaction with antiretroviral medications. Conclusion: HIV-positive individuals known in general practice now consult on a similar scale to the wider population. Further research should be undertaken to explore how primary care can best contribute to improving the health outcomes of this group with chronic illness. Their substantial use of primary care suggests there may be potential to develop effective integrated care pathways

    A Bayesian framework to objectively combine metrics when developing stressor specific multimetric indicator

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    In the context of the European Water Framework Directive (WFD), monitoring programs and related indicators have been developed to assess anthropogenic impacts on various components of aquatic ecosystems. While great precautions are usually taken when selecting and calculating relevant core metrics, little attention is generally paid to the generation of the multimetric indicator, i.e. the combination of the different core metrics. Indeed, most multimetric indicators are generated by simply averaging or summing metrics, without taking into account their sensitivity and their variability. Moreover, few indicators provide a rigorous estimate of the uncertainty of the assessments, while this estimation is essential for managers. In this context, we developed a Bayesian framework to build multimetric indicators aiming at improving those two weaknesses. This framework is based on two phases. First, pressure-impact statistical models are developed to quantify the impact of pressure on various fish metrics. Then the Bayesian theorem is applied to estimate probabilities of being at a certain anthropogenic pressure level from fish observation and pressure-impact models outputs. The Bayesian theorem allows to combine objectively the different core metrics, taking into account their sensitivity and their variability, and to provide rigorous uncertainty quantification, which is especially valuable in the WFD context. The method is applied as illustrative example on transitional French water bodies to demonstrate its relevance, especially in the Water Framework Directive context though the method is generic enough to be applied in various contexts

    Where do we diagnose HIV infection? Monitoring new diagnoses made in nontraditional settings in England, Wales and Northern Ireland.

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    OBJECTIVES: The objectives of the study were to describe 10-year trends in HIV diagnosis setting and to explore predictors of being diagnosed outside a sexual health clinic (SHC). METHODS: Analyses of national HIV surveillance data were restricted to adults (aged ≥ 15 years) diagnosed in 2005-2014 in England, Wales and Northern Ireland. Logistic regression identified factors associated with diagnosis outside an SHC (2011-2014). RESULTS: Between 2005 and 2014, 63 599 adults were newly diagnosed with HIV infection; 83% had a diagnosis setting reported. Most people were diagnosed in SHCs (69%) followed by: medical admissions/accident and emergency (A&E; 8.6%), general practice (6.4%), antenatal services (5.5%), out-patient services (3.6%), infectious disease units (2.7%) and other settings (4.0%). The proportion of people diagnosed outside SHCs increased from 2005 to 2014, overall (from 27% to 32%, respectively) and among men who have sex with men (MSM) (from 14% to 21%) and black African men (from 25% to 37%) and women (from 39% to 52%) (all trend P < 0.001). Median CD4 increased across all settings, but was highest in SHCs (384 cells/μL) and lowest in medical admissions/A&E (94 cells/μL). Predictors of being diagnosed outside SHCs included: acquiring HIV through heterosexual contact [adjusted odds ratio (aOR) 1.99; 95% confidence interval (CI) 1.81-2.18] or injecting drug use (aOR: 3.28; 95% CI: 2.56-4.19; reference: MSM), being diagnosed late (< 350 cells/μL) (aOR: 2.55; 95% CI: 2.36-2.74; reference: diagnosed promptly) and being of older age at diagnosis (35-49 years: aOR: 1.60; 95% CI: 1.39-1.83; ≥ 50 years: aOR: 2.48; 95% CI: 2.13-2.88; reference: 15-24 years). CONCLUSIONS: The proportion of HIV diagnoses made outside SHCs has increased over the past decade in line with evolving HIV testing guidelines. However, the rate of late diagnosis remains high, indicating that further expansion of testing is necessary, as many people may have had missed opportunities for earlier diagnosis

    Associations with sub-optimal clinic attendance and reasons for missed appointments among heterosexual women and men living with HIV in London

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    Poor engagement in HIV care is associated with poorer health outcomes and increased mortality. Our survey examined experiential and circumstantial factors associated with clinic attendance among women (n = 250) and men (n = 106) in London with heterosexually-acquired HIV. While no associations were found for women, among men, sub-optimal attendance was associated with insecure immigration status (25.6% vs. 1.8%), unstable housing (32.6% vs. 10.2%) and reported effect of HIV on daily activities (58.7% vs. 40.0%). Among women and men on ART, it was associated with missing doses of ART (OR = 2.96, 95% CI:1.74-5.02), less belief in the necessity of ART (OR = 0.56, 95% CI:0.35-0.90) and more concern about ART (OR = 3.63, 95% CI:1.45-9.09). Not wanting to think about being HIV positive was the top reason for ever missing clinic appointments. It is important to tackle stigma and the underlying social determinants of health to improve HIV prevention, and the health and well-being of people living with HIV
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