891 research outputs found

    Imagining and producing the 'good' migrant: the role of recruitment agencies in shaping bodily goodness

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    This paper focuses on representations of labour migrants and interrogates how such imaginaries shape migrant recruitment and employment regimes. The recruitment and employment of labour migrants inevitably involves a range of knowledge practices which affect who is recruited, from where and for what purposes. In particular this paper seeks to advance understandings of how images of ‘bodily goodness’ are represented graphically and how perceptions of migrant workers influence the recruitment of workers from Latvia. The analysis results in a schema of the ‘filtering’ processes that are enacted to ‘produce’ the ‘ideal’ migrant worker

    Thermoplastic coating of carbon fibers

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    A continuous powder coating system was developed for coating carbon fiber with LaRC-TPI (Langley Research Center-Thermoplastic Polyimide), a high-temperature thermoplastic polymide invented by NASA-Langley. The coating line developed used a pneumatic fiber spreader to separate the individual fibers. The polymer was applied within a recirculating powder coating chamber then melted using a combination of direct electrical resistance and convective heating to make it adhere to the fiber tow. The tension and speed of the line were controlled with a dancer arm and an electrically driven fiber wind-up and wind-off. The effects of heating during the coating process on the flexibility of the prepreg produced were investigated. The uniformity with which the fiber tow could be coated with polymer also was examined. Composite specimens were fabricated from the prepreg and tested to determine optimum process conditions. The study showed that a very uniform and flexible prepeg with up to 50 percent by volume polymer could be produced with this powder coating system. The coating line minimized powder loss and produced prepeg in lengths of up to 300 m. The fiber spreading was found to have a major effect on the coating uniformity and flexibility. Though test results showed low composite tensile strengths, analysis of fracture surfaces under scanning electron microscope indicated that fiber/matrix adhesion was adequate

    The enigmatic young object : Walker 90/V590 Monocerotis

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    Aims. We assess the evolutionary status of the intriguing object Walker 90/V590 Mon, which is located about 20 arcmin northwest of the Cone Nebula near the center of the open cluster NGC 2264. This object, according to its most recent optical spectral type determination (B7), which we confirmed, is at least 3 mag too faint in V for the cluster distance, but it shows the classical signs of a young pre-main sequence object, such as highly variable H emission, Mg II emission, IR excess, UV continuum, and optical variability. Methods. We analyzed a collection of archival and original data on Walker 90, covering 45 years including photometry, imaging, and spectroscopic data ranging from ultraviolet to near-infrared wavelengths. Results. According to star formation processes, it is expected that, as this object clears its primordial surroundings, it should become optically brighter, show a weakening of its IR excess and present decreasing line emissions. This behavior is supported by our observations and analysis, but timescales are expected to be longer than the one observed here. Based on photometric data secured in 2007, we find Walker 90 at its brightest recorded optical magnitude √(12.47 ± 0.06). We document an evolution in spectral type over the past five decades (from A2/A3 to currently B7 and as early as B4), along with a decrease in the near-infrared K fluxes. From near-infrared VISIR images secured in 2004, Walker 90 appears as a point source placing an upper limit of < 0.1" for its diameter. Evidence of turbulent inflows is found in rapidly changing inverse P-Cygni profiles in the lower Balmer lines, with a broadening of ±400 km s-1 in Hα and a redshifted component in HÎČ with a terminal velocity of ~600 km s-1. The measured steep UV continuum fluxes (mimicking a star as early as B4), added to a tentative identification of N V emission, suggest a strong non-photospheric component, typically of fluxes arising from a thermally inhomogeneous accretion disk. We detect a well defined 2200 Å bump, indicative of dense material in the line-of-sight. We conclude that many observational features are explained if W90 is a flared disk system, surrounded by an inclined optically thick accretion disk

    A young stellar group associated with HD 199143 (d = 48 pc)

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    We present new optical and ultraviolet spectroscopy of the anomalous EUV emitter HD 199143 (F8V). High resolution spectra in the Halpha and Na I D wavelength regions show evidence for very rapid (a few hundred km/s) rotation of the stellar photosphere. Using archive IRAS data we also show that the star has excess emission above photospheric levels at 12 micron. IUE data of HD199143 reveal the presence of emission lines of Mg II, C I, C II, C III, C IV, Si IV, He II and N V and show a large variability, both in the continuum and line fluxes. We propose that all available data of HD 199143 can be explained by assuming that is has been spun up by accretion of material from a close T Tauri like companion, responsible for the emission lines, the ultraviolet variability and the excess infrared emission. The bursting or flaring nature of this object, mostly in high energies, could be explained as episodic mass transfer between the star and its close companion. We show that HD 199143 and the Li-rich late-type dwarf BD-17 6128 form a physical pair and suggest that both may be part of a new nearby (48 pc) young (approx. 10^7 yr) stellar association in Capricornius.Comment: 4 pages, 6 figures, to appear in Astronomy & Astrophysics (Letters

    Consequences on ethylene metabolism of inactivating the ethylene receptor sites in diseased non-climacteric fruit

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    Abstract Penicillium digitatum-infected grapefruit synthesize large quantities of the stress hormone ethylene. The compound 1-methylcyclopropene (1-MCP) inhibits the binding of ethylene to the ethylene receptor site, the ethylene binding protein (EBP). Treating infected fruit with 1-MCP prevented infection-induced degreening, such that fumigated fruit retained their green immature color compared to yellow non-fumigated controls. However, 1-MCP treatment significantly increased whole fruit ethylene production. In flavedo tissue of infected non-1-MCP treated fruit, 1-aminocyclopropane-1-carboxylate (ACC) synthase transcript accumulation, ACC synthase (ACS) enzyme activity, ACC and ethylene synthesis were all significantly higher + 5 mm ahead of the lesion front than in uninfected non-1-MCP treated controls, but decreased significantly with increased sampling distance away from the lesion. 1-MCP treatment increased ethylene production in infected fruit at all three sampling distances compared to the non-fumigated samples. Even in the absence of infection, 1-MCP treatment resulted in increased ethylene synthesis. The results suggest that, in the presence of a pathogenic stress, blocking the EBPs prevented regulatory control of the ethylene biosynthetic pathway that resulted in an uninhibited expression of the ACS stress-associated genes, increased ACS activity and elevated ACC accumulation and ethylene production. Blocking of the EBPs with 1-MCP did not affect progression of the pathogen through the fruit. Published by Elsevier Science B.V

    Mapping interactions between the sustainable development goals: lessons learned and ways forward

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    Pursuing integrated research and decision-making to advance action on the sustainable development goals (SDGs) fundamentally depends on understanding interactions between the SDGs, both negative ones (“trade-offs”) and positive ones (“co-benefits”). This quest, triggered by the 2030 Agenda, has however pointed to a gap in current research and policy analysis regarding how to think systematically about interactions across the SDGs. This paper synthesizes experiences and insights from the application of a new conceptual framework for mapping and assessing SDG interactions using a defined typology and characterization approach. Drawing on results from a major international research study applied to the SDGs on health, energy and the ocean, it analyses how interactions depend on key factors such as geographical context, resource endowments, time horizon and governance. The paper discusses the future potential, barriers and opportunities for applying the approach in scientific research, in policy making and in bridging the two through a global SDG Interactions Knowledge Platform as a key mechanism for assembling, systematizing and aggregating knowledge on interactions

    Validation of a Multivariate Serum Profile for Epithelial Ovarian Cancer Using a Prospective Multi-Site Collection

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    In previous studies we described the use of a retrospective collection of ovarian cancer and benign disease samples, in combination with a large set of multiplexed immunoassays and a multivariate pattern recognition algorithm, to develop an 11-biomarker classification profile that is predictive for the presence of epithelial ovarian cancer. In this study, customized, Luminex-based multiplexed immunoassay kits were GMP-manufactured and the classification profile was refined from 11 to 8 biomarkers (CA-125, epidermal growth factor receptor, CA 19-9, C-reactive protein, tenascin C, apolipoprotein AI, apolipoprotein CIII, and myoglobin). The customized kits and the 8-biomarker profile were then validated in a double-blinded manner using prospective samples collected from women scheduled for surgery, with a gynecologic oncologist, for suspicion of having ovarian cancer. The performance observed in model development held in validation, demonstrating 81.1% sensitivity (95% CI 72.6 &#x2013; 87.9%) for invasive epithelial ovarian cancer and 85.4% specificity (95% CI 81.1 &#x2013; 88.9%) for benign ovarian conditions. The specificity for normal healthy women was 95.6% (95% CI 83.6 &#x2013; 99.2%). These results have encouraged us to undertake a second validation study arm, currently in progress, to examine the performance of the 8-biomarker profile on the population of women not under the surgical care of a gynecologic oncologist

    Renormalization Group Analysis of a Quivering String Model of Posture Control

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    Scaling concepts and renormalization group (RG) methods are applied to a simple linear model of human posture control consisting of a trembling or quivering string subject to damping and restoring forces. The string is driven by uncorrelated white Gaussian noise intended to model the corrections of the physiological control system. We find that adding a weak quadratic nonlinearity to the posture control model opens up a rich and complicated phase space (representing the dynamics) with various non-trivial fixed points and basins of attraction. The transition from diffusive to saturated regimes of the linear model is understood as a crossover phenomenon, and the robustness of the linear model with respect to weak non-linearities is confirmed. Correlations in posture fluctuations are obtained in both the time and space domain. There is an attractive fixed point identified with falling. The scaling of the correlations in the front-back displacement, which can be measured in the laboratory, is predicted for both the large-separation (along the string) and long-time regimes of posture control.Comment: 20 pages, 13 figures, RevTeX, accepted for publication in PR

    Multicenter study of hypoxemia prevalence and quality of oxygen treatment for hospitalized Malawian children

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    Although hypoxemic children have high mortality, little is known about hypoxemia prevalence and oxygen administration in African hospitals. We aimed to determine the hypoxemia prevalence and quality of oxygen treatment by local clinicians for hospitalized Malawian children

    Thermoplastic coating of carbon fibers

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    Now that quantities of prepreg were made on the thermoplastic coating line, they are being formed into both textile preform structures and directly into composite samples. The textile preforms include both woven and knitted structures which will be thermoformed into a finished part. In order to determine if the matrix resin is properly adhering to the fibers or if voids are being formed in the coating process, the tensile strength and modulus of these samples will be tested. The matrix uniformity of matrix distribution in these samples is also being determined using an image analyzer
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