1,059 research outputs found

    International organizations and the problem of child health, 1945-1960

    Get PDF
    Faced with planning mass relief campaigns in liberated Europe in the aftermath of the Second World War, the United Nations Relief and Rehabilitation Administra­tion relied heavily on cheap supplies of skimmed milk from surplus production in northern Europe. The success of this approach swept aside more detailed planning around restoring national maternal and children’s health services. This reliance on mass feeding continued into the post-war years. UNICEF, the agency with the most substantial financial resources, continued this supply-driven approach despite growing reservations by nutritionists in its rival agencies —the UN Food and Agricultural Organization and the World Health Organization

    Counterion Condensation on Spheres in the Salt-free Limit

    Full text link
    A highly-charged spherical colloid in a salt-free environment exerts such a powerful attraction on its counterions that a certain fraction condenses onto the surface of a particle. The degree of condensation depends on the curvature of the surface. So, for instance, condensation is triggered on a highly-charged sphere only if the radius exceeds a certain critical radius \collrad^{*}. \collrad^{*} is expected to be a simple function of the volume fraction of particles. To test these predictions, we prepare spherical particles which contain a covalently-bound ionic liquid, which is engineered to dissociate efficiently in a low-dielectric medium. By varying the proportion of ionic liquid to monomer we synthesise nonpolar dispersions of highly-charged spheres which contain essentially no free co-ions. The only ions in the system are counterions generated by the dissociation of surface-bound groups. We study the electrophoretic mobility of this salt-free system as a function of the colloid volume fraction, the particle radius, and the bare charge density and find evidence for extensive counterion condensation. At low electric fields, we observe excellent agreement with Poisson-Boltzmann predictions for counterion condensation on spheres. At high electric fields however, where ion advection is dominant, the electrophoretic mobility is enhanced significantly which we attribute to hydrodynamic stripping of the condensed layer of counterions from the surface of the particle.Comment: 13 pages, 9 figures and two table

    Localization and Substrate Specificity of Glycosidases in Vacuoles of Nicotiana rustica

    Full text link

    Identifying defects in aerospace composite sandwich panels using high-definition distributed optical fibre sensors

    Get PDF
    Automated methods for detecting defects within composite materials are highly desirable in the drive to increase throughput, optimise repair program effectiveness and reduce component replacement. Tap-testing has traditionally been used for detecting defects but does not provide quantitative measurements, requiring secondary techniques such as ultrasound to certify components. This paper reports on an evaluation of the use of a distributed temperature measurement system—high-definition fibre optic sensing (HD-FOS)—to identify and characterise crushed core and disbond defects in carbon fibre reinforced polymer (CFRP)-skin, aluminium-core, sandwich panels. The objective is to identify these defects in a sandwich panel by measuring the heat transfer through the panel thickness. A heater mat is used to rapidly increase the temperature of the panel with the HD-FOS sensor positioned on the top surface, measuring temperature. HD-FOS measurements are made using the Luna optical distributed sensor interrogator (ODISI) 9100 system comprising a sensor fabricated using standard single mode fibre (SMF)-20 of external diameter 250 µm, including the cladding. Results show that areas in which defects are present modulate thermal conductivity, resulting in a lower surface temperature. The resultant data are analysed to identify the length, width and type of defect. The non-invasive technique is amenable to application in challenging operational settings, offering high-resolution visualisation and defect classification

    Does Access to Health Care Impact Survival Time after Diagnosis of AIDS?

    Full text link
    Lack of access to health care is often blamed for poor health outcomes, but this effect is not supported by existing HIV/AIDS literature. The authors examined the association between access to care and survival time after progression to AIDS, using survival analysis methods. This study combined data from two CDC sponsored studies of HIV-infected persons, a cross-sectional interview study and a longitudinal medical record review study. Study subjects included 752 persons who progressed to AIDS before December 31, 1999, and were patients at either of two major HIV care facilities in Detroit, MIchigan. Separate statistical models were used to test associations between survival time after meeting the criteria for AIDS and two indicators of access to health care: (1) perceived access to health care and (2) health care utilization patterns. Perceived access was not associated with survival time after AIDS, but patterns of health care utilization were significantly associated with survival time after AIDS (HR = 2.04, p < 0.001). Individuals who received a greater proportion of their care in the ER had a worse survival prognosis than those who received more of their health care in an outpatient clinic setting. It is crucial that we provide HIV-infected populations with tools that enable them to access a regular source of health care.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63272/1/10872910252972276.pd

    Molecular detection of Toxoplasma gondii in water samples from Scotland and a comparison between the 529bp real-time PCR and ITS1 nested PCR

    Get PDF
    Waterborne transmission of Toxoplasma gondii is a potential public health risk and there are currently no agreed optimised methods for the recovery, processing and detection of T. gondii oocysts in water samples. In this study modified methods of T. gondii oocyst recovery and DNA extraction were applied to 1427 samples collected from 147 public water supplies throughout Scotland. T. gondii DNA was detected, using real time PCR (qPCR) targeting the 529bp repeat element, in 8.79% of interpretable samples (124 out of 1411 samples). The samples which were positive for T. gondii DNA originated from a third of the sampled water sources. The samples which were positive by qPCR and some of the negative samples were reanalysed using ITS1 nested PCR (nPCR) and results compared. The 529bp qPCR was the more sensitive technique and a full analysis of assay performance, by Bayesian analysis using a Markov Chain Monte Carlo method, was completed which demonstrated the efficacy of this method for the detection of T. gondii in water samples

    Comparing methods suitable for monitoring marine mammals in low visibility conditions during seismic surveys

    Get PDF
    Funding: This work was supported by the Joint Industry Programme on E&P Sound and Marine Life - Phase III. TAM was partially supported by CEAUL (funded by FCT - Fundação para a Ciência e a Tecnologia, Portugal, through the project UID/MAT/00006/2013).Loud sound emitted during offshore industrial activities can impact marine mammals. Regulations typically prescribe marine mammal monitoring before and/or during these activities to implement mitigation measures that minimise potential acoustic impacts. Using seismic surveys under low visibility conditions as a case study, we review which monitoring methods are suitable and compare their relative strengths and weaknesses. Passive acoustic monitoring has been implemented as either a complementary or alternative method to visual monitoring in low visibility conditions. Other methods such as RADAR, active sonar and thermal infrared have also been tested, but are rarely recommended by regulatory bodies. The efficiency of the monitoring method(s) will depend on the animal behaviour and environmental conditions, however, using a combination of complementary systems generally improves the overall detection performance. We recommend that the performance of monitoring systems, over a range of conditions, is explored in a modelling framework for a variety of species.Publisher PDFPeer reviewe

    Laboratory test results after living liver donation in the adult-to-adult living donor liver transplantation cohort study

    Full text link
    Information on the long-term health of living liver donors is incomplete. Because changes in standard laboratory tests may reflect the underlying health of donors, results before and after donation were examined in the Adult-to-Adult Living Donor Liver Transplantation Cohort Study (A2ALL). A2ALL followed 487 living liver donors who donated at 9 US transplant centers between 1998 and 2009. The aminotransferase [aspartate aminotransferase (AST) and alanine aminotransferase (ALT)] and alkaline phosphatase (AP) activities, bilirubin, international normalized ratio (INR), albumin, white blood cell count (WBC), hemoglobin (HGB), platelet count, ferritin, serum creatinine (SCR), and blood urea nitrogen (BUN) were measured at the evaluation and after donation (1 week, 1 month, 3 months, 1 year, and yearly thereafter). Repeated measures models were used to estimate median laboratory values at each time point and to test for differences between values at the evaluation (baseline) and postdonation time points. Platelet counts were significantly decreased at every time point in comparison with the baseline, and at 3 years, they were 19% lower. Approximately 10% of donors had a platelet count < 150 × 1000/mm 3 2 to 3 years post-donation. Donors with a platelet count ≤ 150 × 1000/mm 3 at 1 year had significantly lower mean platelet counts (189 ± 32 × 1000/mm 3 ) versus the remainder of the cohort (267 ± 56 × 1000/mm 3 , P < 0.0001) at the evaluation. Statistically significant differences compared to the evaluation values were noted for AST, AP, INR, and albumin through the first year, although most measurements were in the normal range. The median values for WBC, HGB, ferritin, albumin, SCR, BUN, and INR were not substantially outside the normal range at any time point. In conclusion, after 3 months, most laboratory values return to normal among right hepatic lobe liver donors, with a slower return to baseline levels for AST, AP, INR, and albumin. Persistently decreased platelet counts warrant further investigation. Liver Transpl, 2011. © 2011 AASLD.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/83476/1/22246_ftp.pd
    • …
    corecore