444 research outputs found

    Orderability and rigidity in contact geometry

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    We study the existence of positive loops of contactomorphisms on a Liouville-fillable contact manifold (&Sgr;, ξ = ker(α)). Previous results (see [1]) show that a large class of Liouville-fillable contact manifolds admit contractible positive loops. In contrast, we show that for any Liouville-fillable (&Sgr;, α) with dim(&Sgr;) ≥ 7, there exists a Liouville-fillable contact structure ξ\u27 on &Sgr; which admits no positive loop at all. Further, ξ\u27 can be chosen to agree with ξ\u27 on the complement of a Darboux ball. We then define a relative version of orderability for a Legendrian submanifold, and discuss the relationship between the two notions

    J\u27accuse: University termed insensitive to Franco-Americans

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    The University of Maine has neither the knowledge, the experience, nor the sensitivity to listen to and understand the problems of its Franco-American students, says Yvon Labbé, co-ordinator of the Franco-American Project on the Orono campus

    Trace element analysis of bighorn sheep horns

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    A total of 249 samples of horn material from bighorn sheep was collected from nine locations. The concentrations of eight elements were determined in all samples by inductively coupled argon plasma spectroscopy. Year of horn growth was determined for 154 of the samples. All elements of concentrations varied significantly with respect to location. Some elements varied similarly to other elements with respect to location, but most locations exhibited unique element concentration profiles. Six of eight elements exhibited significant variation with respect to year of horn growth. A general pattern of annual element concentration fluctuation appeared to emerge. Generally, for a given year, if one element occurred in relatively higher or lower concentrations with respect to the previous year, the other study elements were found to occur in relatively higher or lower concentrations, respectively, as well. Neither plant element concentrations nor precipitation were found to be significantly related to horn element concentrations. Correlation analysis of bighorn sheep hair element concentration and horn element concentration revealed no significant relationships

    Holistic evaluation of aircraft detection lighting systems for wind turbines in Germany using a multi-method evaluation framework

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    Transponder-based Aircraft Detection Lighting Systems (ADLS) are increasingly used in wind turbines to limit beacon operation times, reduce light emissions, and increase wind energy acceptance. The systems use digital technologies such as receivers of digital transponder signals, LTE/5G, and other information and communication technology. The use of ADLS will be mandatory in Germany both for new and existing wind turbines with a height of >100 m from 2023 (onshore) and 2024 (offshore), so a nationwide rollout is expected to start during 2022. To fully realize the benefits while avoiding risks and bottlenecks, a thorough and holistic understanding of the efforts required and the impacts caused along the life cycle of an ADLS is essential. Therefore, this study presents the first multi-aspect holistic evaluation of an ADLS. A framework for evaluating digital applications in the energy sector, previously developed by the authors, is refined and applied. The framework is based on multi-criteria analysis (MCA), life cycle assessment (LCA), and expert interviews. On an aggregated level, the MCA results show an overall positive impact from all stakeholders’ perspectives. Most positive impacts are found in the society and politics category, while most negative impacts are of technical nature. The LCA of the ADLS reveals a slightly negative impact, but this impact is negligible when compared to the total life cycle impact of the wind turbines of which the ADLS is a part. Besides the aggregated evaluation, detailed information on potential implementation risks, bottlenecks, and levers for life cycle improvement are presented. In particular, the worldwide scarcity of the required semiconductors, in combination with the general lack of technicians in Germany, lead to the authors’ recommendation for a limited prolongation of the planned rollout period. This period should be used by decision-makers to ensure the availability of technical components and installation capacities. A pooling of ADLS installations in larger regions could improve plannability for manufacturers and installers. Furthermore, an ADLS implementation in other countries could be supported by an early holistic evaluation using the presented framework

    HIV and Hepatitis C-Coinfected Patients Have Lower Low-Density Lipoprotein Cholesterol Despite Higher Proprotein Convertase Subtilisin Kexin 9 (PCSK9): An Apparent "PCSK9-Lipid Paradox".

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    BackgroundProprotein convertase subtilisin kexin 9 (PCSK9) inhibitors reduce low-density lipoprotein cholesterol (LDL-C) and improve outcomes in the general population. HIV-infected individuals are at increased risk for cardiovascular events and have high rates of dyslipidemia and hepatitis C virus (HCV) coinfection, making PCSK9 inhibition a potentially attractive therapy.Methods and resultsWe studied 567 participants from a clinic-based cohort to compare PCSK9 levels in patients with HIV/HCV coinfection (n=110) with those with HIV infection alone (n=385) and with uninfected controls (n=72). The mean age was 49 years, and the median LDL-C level was 100 mg/dL (IQR 77-124 mg/dL); 21% were taking statins. The 3 groups had similar rates of traditional risk factors. Total cholesterol, LDL-C, and high-density lipoprotein cholesterol levels were lower in coinfected patients compared with controls (P<0.001). PCSK9 was 21% higher in HIV/HCV-coinfected patients versus controls (95% CI 9-34%, P<0.001) and 11% higher in coinfected individuals versus those with HIV infection alone (95% CI 3-20%, P=0.008). After adjustment for cardiovascular risk factors, HIV/HCV coinfection remained significantly associated with 20% higher PCSK9 levels versus controls (95% CI 8-33%, P=0.001). Interleukin-6 levels increased in a stepwise fashion from controls (lowest) to HIV-infected to HIV/HCV-coinfected individuals (highest) and correlated with PCSK9 (r=0.11, P=0.018).ConclusionsDespite having lower LDL-C, circulating PCSK9 levels were increased in patients coinfected with HIV and HCV in parallel with elevations in the inflammatory, proatherogenic cytokine interleukin-6. Clinical trials should be conducted to determine the efficacy of targeted PCSK9 inhibition in the setting of HIV/HCV coinfection

    Effect of provider-initiated testing and counselling and integration of ART services on access to HIV diagnosis and treatment for children in Lilongwe, Malawi: a pre- post comparison

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    <p>Abstract</p> <p>Background</p> <p>The HIV prevalence in Malawi is 12% and Kamuzu Central Hospital (KCH), in the capital Lilongwe, is the main provider of adult and paediatric HIV services in the central region. The Lighthouse at KCH offers opt-in HIV testing and counselling (HTC) for adults and children. In June 2004, Lighthouse was the first clinic to provide free antiretroviral treatment (ART) in the public sector, but few children accessed the services. In response, provider-initiated HIV testing and counselling (PITC) and an ART clinic were introduced at the paediatric department at KCH in Quarter 4 (Q4) 2004.</p> <p>Methods</p> <p>We analysed prospectively collected, aggregated data of quarterly reports from Q1 2003 to Q4 2006 from HTC centre registers, ART registers and clinic registrations at the ART clinics of both Lighthouse and the paediatric department. By comparing data of both facilities before (Q1 2003 to Q3 2004), and after the introduction of the services at the paediatric department (Q4 2004 to Q4 2006), we assessed the effect of this intervention on the uptake of HIV services for children at KCH.</p> <p>Results</p> <p>Overall, 3971 children were tested for HIV, 2428 HIV-infected children were registered for care and 1218 started ART. Between the two periods, the median (IQR) number of children being tested, registered and starting ART per quarter rose from 101 (53-109) to 358 (318-440), 56 (50-82) to 226 (192-234) and 18 (8-23) to 139 (115-150), respectively. The median proportion of tested clients per quarter that were children rose from 3.8% (2.7-4.3) to 9.6% (8.8 to 10.0) (p = 0.0009) and the proportion of ART starters that were children rose from 6.9% (4.9-9.3) to 21.1% (19.2-24.2) (p = 0.0036). The proportion of registered children and adults starting ART each quarter increased similarly, from 26% to 53%, and 20% to 52%, respectively.</p> <p>Conclusions</p> <p>Implementation of PITC and integration of ART services within the paediatric ward are likely to be the main reasons for improved access to HTC and ART for children at KCH, and can be recommended to other hospitals with paediatric inpatients in resource limited settings with high HIV prevalence.</p

    Seroprevalence of CMV, HSV-2 and HBV among HIV-Infected Malawian Children: A Cross-sectional Survey

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    BACKGROUND: Little is known about viral co-infections in African human immunodeficiency virus (HIV)-infected children. We examined the prevalence of seromarkers for cytomegalovirus (CMV), herpes simplex virus type 2 (HSV-2) and hepatitis B virus (HBV) infections among HIV-infected, antiretroviral treatment (ART)-naive children in Lilongwe, Malawi. METHODS: Ninety-one serum samples were tested for IgG and IgM antibodies to CMV, and IgG antibodies to HSV-2 and hepatitis B surface antigen (HBsAg). Baseline demographic, clinical and laboratory data were abstracted from electronic records. RESULTS: CMV IgG was the most common positive result in all age groups (in 73% of children <1 year, and 100% in all other groups). Three patients were CMV IgM positive (3.3%), suggesting acute infection. HSV-2 IgG was positive in four patients (4.4%), and HBsAg in two (2.2%). CONCLUSIONS: CMV infection occurred early in life, and few children had specific signs of CMV infection at the time of ART initiation. Unrecognized HBV infection represents opportunities for testing and treatment of HIV/HBV co-infected children
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