High-frequency transport in pp-type Si/Si0.87_{0.87}Ge0.13_{0.13} heterostructures studied with surface acoustic waves in the quantum Hall regime

The interaction of surface acoustic waves (SAW) with $p$-type Si/Si$_{0.87}$Ge$_{0.13}$ heterostructures has been studied for SAW frequencies of 30-300 MHz. For temperatures in the range 0.7$<T<$1.6 K and magnetic fields up to 7 T, the SAW attenuation coefficient $\Gamma$ and velocity change $\Delta V /V$ were found to oscillate with filling factor. Both the real $\sigma_1$ and imaginary $\sigma_2$ components of the high-frequency conductivity have been determined and compared with quasi-dc magnetoresistance measurements at temperatures down to 33 mK. By analyzing the ratio of $\sigma_1$ to $\sigma_2$, carrier localization can be followed as a function of temperature and magnetic field. At $T$=0.7 K, the variations of $\Gamma$, $\Delta V /V$ and $\sigma_1$ with SAW intensity have been studied and can be explained by heating of the two dimensional hole gas by the SAW electric field. Energy relaxation is found to be dominated by acoustic phonon deformation potential scattering with weak screening.Comment: Accepted for publication in PR

A comparison of HAART outcomes between the US military HIV Natural History Study (NHS) and HIV Atlanta Veterans Affairs Cohort Study (HAVACS).

INTRODUCTION: The Department of Defense (DoD) and the Department of Veterans Affairs (VA) provide comprehensive HIV treatment and care to their beneficiaries with open access and few costs to the patient. Individuals who receive HIV care in the VA have higher rates of substance abuse, homelessness and unemployment than individuals who receive HIV care in the DoD. A comparison between individuals receiving HIV treatment and care from the DoD and the VA provides an opportunity to explore the impact of individual-level characteristics on clinical outcomes within two healthcare systems that are optimized for clinic retention and medication adherence. METHODS: Data were collected on 1065 patients from the HIV Atlanta VA Cohort Study (HAVACS) and 1199 patients from the US Military HIV Natural History Study (NHS). Patients were eligible if they had an HIV diagnosis and began HAART between January 1, 1996 and June 30, 2010. The analysis examined the survival from HAART initiation to all-cause mortality or an AIDS event. RESULTS: Although there was substantial between-cohort heterogeneity and the 12-year survival of participants in NHS was significantly higher than in HAVACS in crude analyses, this survival disparity was reduced from 21.5% to 1.6% (mortality only) and 26.8% to 4.1% (combined mortality or AIDS) when controlling for clinical and demographic variables. CONCLUSION: We assessed the clinical outcomes for individuals with HIV from two very similar government-sponsored healthcare systems that reduced or eliminated many barriers associated with accessing treatment and care. After controlling for clinical and demographic variables, both 12-year survival and AIDS-free survival rates were similar for the two study cohorts who have open access to care and medication despite dramatic differences in socioeconomic and behavioral characteristics

The per-protocol effect of immediate versus deferred antiretroviral therapy initiation

The START trial found a lower risk of a composite clinical outcome in HIV-positive individuals assigned to immediate initiation of antiretroviral therapy (ART) compared with those assigned to deferred initiation. However, 30% of those assigned to deferred initiation started ART earlier than the protocol specified. To supplement the published intention-to-treat effect estimates, here we estimate the per-protocol effect of immediate versus deferred ART initiation in START

Adult systemic cat scratch disease associated with therapy for hepatitis C

BACKGROUND: We describe the first case of systemic cat scratch disease in a patient receiving peginterferon α-2a and ribavirin for treatment of hepatitis C. Cases of adult systemic CSD are extremely infrequent and immunomodulatory treatment for hepatitis C has been associated with aberrant host responses to common pathogens. CASE PRESENTATION: A 52 year old man being treated for hepatitis C presented with diffuse lymphadenopathy, weight loss, fevers and splenic lesions. Symptoms were initially confused with adverse effects of his regimen, delaying recognition of his infection. Diagnostic investigation, including histopathology, microbiology and serologic parameters, confirmed that his illness was due to disseminated cat scratch disease with Bartonella henselae. CONCLUSION: Disseminated CSD is exceptionally rare in adults. We describe the first case of disseminated cat scratch disease associated with peginterferon α and ribavirin to alert clinicians of the need to be aware of unusual manifestations of common infections in this population

Identifying factors relevant in the assessment of return-to-work efforts in employees on long-term sickness absence due to chronic low back pain: a focus group study

ABSTRACT: BACKGROUND: Efforts undertaken during the return to work (RTW) process need to be sufficient to prevent unnecessary applications for disability benefits. The purpose of this study was to identify factors relevant to RTW Effort Sufficiency (RTW-ES) in cases of sick-listed employees with chronic low back pain (CLBP). METHODS: Using focus groups consisting of Labor Experts (LE's) working at the Dutch Social Insurance Institute, arguments and underlying grounds relevant to the assessment of RTW-ES were investigated. Factors were collected and categorized using the International Classification of Functioning, Disability and Health (ICF model). RESULTS: Two focus groups yielded 19 factors, of which 12 are categorized in the ICF model under activities (e.g. functional capacity) and in the personal (e.g. age, tenure) and environmental domain (e.g. employer-employee relationship). The remaining 7 factors are categorized under intervention, job accommodation and measures. CONCLUSIONS: This focus group study shows that 19 factors may be relevant to RTW-ES in sick-listed employees with CLBP. Providing these results to professionals assessing RTW-ES might contribute to a more transparent and systematic approach. Considering the importance of the quality of the RTW process, optimizing the RTW-ES assessment is essential

The impacts of IT capability and marketing capability on supply chain integration: A resource-based perspective

Although previous research has addressed the interface and logical association among marketing, information technology (IT) and supply chain management, there have been few, if any, attempts to investigate how IT capability and marketing capability influence supply chain integration (SCI). Thus, this study investigates the direct and interacting effects of IT capability and marketing capability on SCI. The hypothesised relationships were tested using survey data gathered from 329 firms in China’s manufacturing industry. The results reveal that both IT capability and marketing capability have a significant positive effect on SCI. Interestingly, no significant interaction effect was found, indicating that marketing IT capability and marketing capability influence SCI independently, and not synergistically. However, while IT capability and marketing capability do not interact, IT capability does mediate the impact of marketing capability on SCI

Global patterns in endemicity and vulnerability of soil fungi

Fungi are highly diverse organisms, which provide multiple ecosystem services. However, compared with charismatic animals and plants, the distribution patterns and conservation needs of fungi have been little explored. Here, we examined endemicity patterns, global change vulnerability and conservation priority areas for functional groups of soil fungi based on six global surveys using a high-resolution, long-read metabarcoding approach. We found that the endemicity of all fungi and most functional groups peaks in tropical habitats, including Amazonia, Yucatan, West-Central Africa, Sri Lanka, and New Caledonia, with a negligible island effect compared with plants and animals. We also found that fungi are predominantly vulnerable to drought, heat and land-cover change, particularly in dry tropical regions with high human population density. Fungal conservation areas of highest priority include herbaceous wetlands, tropical forests, and woodlands. We stress that more attention should be focused on the conservation of fungi, especially root symbiotic arbuscular mycorrhizal and ectomycorrhizal fungi in tropical regions as well as unicellular early-diverging groups and macrofungi in general. Given the low overlap between the endemicity of fungi and macroorganisms, but high conservation needs in both groups, detailed analyses on distribution and conservation requirements are warranted for other microorganisms and soil organisms

Exploring the environmental strategy of big energy companies to drive sustainability

The purpose of this research is to provide an in-depth evaluation of the environmental strategy of the biggest energy companies to drive sustainability, i.e., for both business and the environment as a collective entity. Rooted in the theory of Corporate Social Responsibility (CSR), a secondary data analysis was conducted on the top five energy companies (i.e., British Petroleum (BP), Exxon Mobil, Gazprom, Sinopec and Saudi Aramco) as published by Enercom (2016) to investigate their approach to sustainable development. To do so, each company's environmental strategy was evaluated in order to gain a clear understanding of their implemented procedures for sustainable development towards future. This research paper gives an insight in to the main energy companies' impact on nature and assesses how sustainable their strategies are towards environmental issues. Through this evaluation, we clearly identified how climate change forces companies to be responsible towards society, the economy, and the environment. This study's finding contributes to the present body of knowledge and highlights how the big energy companies have taken responsibility for their actions towards environmental issues