Highly sensitive GaAs/AlGaAs heterojunction bolometer

PACS: 07.57Kp 95.55 Rg 85.25Pb 85.60Gz Keywords: GaAs/AlGaAs TCR Bolometer Room temperature a b s t r a c t GaAs/AlGaAs multilayer heterojunction structures with different aluminum (Al) fractions and emitter doping densities were tested to identify optimum parameters for high temperature coefficient of resistance (TCR). Higher Al fractions and lower doping densities showed higher TCR. Additionally, p-doped heterojunction structures showed a higher TCR compared to an n-doped one with similar parameters. A p-doped multilayer superlattice heterojunction structure with 30 periods of GaAs/Al 0.57 Ga 0.43 As junctions, operating at room temperature showed a TCR of ∼4% and bolometer like infrared (IR) response up to 20 m with a D* of 1.7 × 10 6 Jones. This TCR is higher than that of VO x or ␣-Si bolometers. At low temperatures (50 K) some of these devices have shown TCR values of over 30%

Access to and utilisation of GP services among Burmese migrants in London: a cross-sectional descriptive study

ABSTRACT: BACKGROUND: An estimated 10,000 Burmese migrants are currently living in London. No studies have been conducted on their access to health services. Furthermore, most studies on migrants in the United Kingdom (UK) have been conducted at the point of service provision, carrying the risk of selection bias. Our cross-sectional study explored access to and utilisation of General Practice (GP) services by Burmese migrants residing in London. METHODS: We used a mixed-method approach: a quantitative survey using self-administered questionnaires was complemented by qualitative in-depth interviews for developing the questionnaire and triangulating the findings of the survey. Overall, 137 questionnaires were received (a response rate of 57%) and 11 in-depth interviews conducted. The main outcome variables of the study included GP registration, barriers towards registration, GP consultations, barriers towards consultations, and knowledge on entitlements to health care. Quantitative data were analysed using descriptive statistics, association tests, and a multivariate analysis using logistic regression. The qualitative information was analysed using content analysis. RESULTS: The respondents were young, of roughly equal gender (51.5% female), well educated, and had a fair level of knowledge on health services in the UK. Although the GP registration rate was relatively high (80%, 109 out of 136), GP service utilisation during the last episode of illness, at 56.8% (54 out of 95), was low. The statistical analysis showed that age being younger than 35 years, lacking prior overseas experience, having an unstable immigration status, having a shorter duration of stay, and resorting to self-medication were the main barriers hindering Burmese migrants from accessing primary health care services. These findings were corroborated by the in-depth interviews. CONCLUSIONS: Our study found that having formal access to primary health care was not sufficient to ensure GP registration and health care utilisation. Some respondents faced difficulties in registering with GP practices. Many of those who have registered prefer to forego GP services in favour of self-medication, partly due to long waiting times and language barriers. To ensure that migrants enjoy the health services they need and to which they are entitled, more proactive steps are required, including those that make health services culturally responsiv

Real or imagined women? Staff representations of international women postgraduate students

In Australia\u27s globalising universities many support staff and teaching staff now work with international women postgraduate students. But are they aware of the issues facing these women, and is their understanding of them adequate? Indeed, how do they represent them? In this paper we draw on a small-scale pilot study involving key university personnel. We argue that the ways in which such staff represent this group of students is problematic. Focusing primarily on academic issues and on the literature on learning styles, we analyse these staff members\u27 representations of international women postgraduate students from a postcolonial perspective. We explore the extent to which such representations, and the learning styles literature that reflects and informs them, are what Edward Said calls \u27Orientalist\u27. In so doing, we point to both the constitution of the international woman student as postcolonial female subject and show how this situates her in relation to the prevalent learning styles discourse. Further we argue that such representations of the students differ in crucial ways from the students\u27 self-representations, suggesting that in certain subtle ways such staff members are engaging with \u27imagined\u27 rather than \u27real\u27 women. <br /

Hyper-precarious lives : Migrants, work and forced labour in the Global North

This paper unpacks the contested inter-connections between neoliberal work and welfare regimes, asylum and immigration controls, and the exploitation of migrant workers. The concept of precarity is explored as a way of understanding intensifying and insecure post-Fordist work in late capitalism. Migrants are centrally implicated in highly precarious work experiences at the bottom end of labour markets in Global North countries, including becoming trapped in forced labour. Building on existing research on the working experiences of migrants in the Global North, the main part of the article considers three questions. First, what is precarity and how does the concept relate to working lives? Second, how might we understand the causes of extreme forms of migrant labour exploitation in precarious lifeworlds? Third, how can we adequately theorize these particular experiences using the conceptual tools of forced labour, slavery, unfreedom and precarity? We use the concept of ‘hyper-precarity’ alongside notions of a ‘continuum of unfreedom’ as a way of furthering human geographical inquiry into the intersections between various terrains of social action and conceptual debate concerning migrants’ precarious working experiences

Week 48 resistance analyses of the once-daily, single-tablet regimen darunavir/cobicistat/emtricitabine/tenofovir alafenamide (D/C/F/TAF) in adults living with HIV-1 from the Phase III Randomized AMBER and EMERALD Trials

Darunavir/cobicistat/emtricitabine/tenofovir alafenamide (D/C/F/TAF) 800/150/200/10 mg is being investigated in two Phase III trials, AMBER (NCT02431247; treatment-naive adults) and EMERALD (NCT02269917; treatment-experienced, virologically suppressed adults). Week 48 AMBER and EMERALD resistance analyses are presented. Postbaseline samples for genotyping/phenotyping were analyzed from protocol-defined virologic failures (PDVFs) with viral load (VL) >= 400 copies/mL at failure/later time points. Post hoc analyses were deep sequencing in AMBER, and HIV-1 proviral DNA from baseline samples (VL = 3 thymidine analog-associated mutations (24% not fully susceptible to tenofovir) detected at screening. All achieved VL <50 copies/mL at week 48 or prior discontinuation. D/C/F/TAF has a high genetic barrier to resistance; no darunavir, primary PI, or tenofovir RAMs were observed through 48 weeks in AMBER and EMERALD. Only one postbaseline M184I/V RAM was observed in HIV-1 of an AMBER participant. In EMERALD, baseline archived RAMs to darunavir, emtricitabine, and tenofovir in participants with prior VF did not preclude virologic response

Immigrant and non-immigrant women's experiences of maternity care: A systematic and comparative review of studies in five countries

Background: Understanding immigrant women’s experiences of maternity care is critical if receiving country care systems are to respond appropriately to increasing global migration. This systematic review aimed to compare what we know about immigrant and non-immigrant women’s experiences of maternity care. Methods: Medline, CINAHL, Health Star, Embase and PsychInfo were searched for the period 1989–2012. First, we retrieved population-based studies of women’s experiences of maternity care (n = 12). For countries with identified population studies, studies focused specifically on immigrant women’s experiences of care were also retrieved (n = 22). For all included studies, we extracted available data on experiences of care and undertook a descriptive comparison. Results: What immigrant and non-immigrant women want from maternity care proved similar: safe, high quality, attentive and individualised care, with adequate information and support. Immigrant women were less positive about their care than non-immigrant women. Communication problems and lack of familiarity with care systems impacted negatively on immigrant women’s experiences, as did perceptions of discrimination and care which was not kind or respectful. Conclusion: Few differences were found in what immigrant and non-immigrant women want from maternity care. The challenge for health systems is to address the barriers immigrant women face by improving communication,increasing women’s understanding of care provision and reducing discrimination

The Arabidopsis thaliana F-box gene HAWAIIAN SKIRT is a new player in the microRNA pathway

In Arabidopsis, the F-box HAWAIIAN SKIRT (HWS) protein is important for organ growth. Loss of function of HWS exhibits pleiotropic phenotypes including sepal fusion. To dissect the HWS role, we EMS-mutagenized hws-1 seeds and screened for mutations that suppress hws-1 associated phenotypes. We identified shs-2 and shs-3 (suppressor of hws-2 and 3) mutants in which the sepal fusion phenotype of hws-1 was suppressed. shs-2 and shs-3 (renamed hst-23/hws-1 and hst-24/hws-1) carry transition mutations that result in premature terminations in the plant homolog of Exportin-5 HASTY (HST), known to be important in miRNA biogenesis, function and transport. Genetic crosses between hws-1 and mutant lines for genes in the miRNA pathway, also suppress the phenotypes associated with HWS loss of function, corroborating epistatic relations between the miRNA pathway genes and HWS. In agreement with these data, accumulation of miRNA is modified in HWS loss or gain of function mutants. Our data propose HWS as a new player in the miRNA pathway, important for plant growth