90 research outputs found

    Quantum measurement of the degree of polarization of a light beam

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    We demonstrate a coherent quantum measurement for the determination of the degree of polarization (DOP). This method allows to measure the DOP in the presence of fast polarization state fluctuations, difficult to achieve with the typically used polarimetric technique. A good precision of the DOP measurements is obtained using 8 type II nonlinear crystals assembled for spatial walk-off compensation.Comment: 4 pages, 3 figure

    Dynamics of Anemia in Relation to Parasitic Infections, Micronutrient Status, and Increasing Age in South-Central Côte d'Ivoire

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    Background. Parasitic diseases (eg, malaria and helminthiases) exert enormous burdens on public health and social well-being. Moreover, parasitic infections are important causes of anemia in tropical Africa, exacerbated by lack of a diversified diet and inflammatory and genetic diseases. There is a paucity of longitudinal studies monitoring the dynamics of anemia in relation to the aforementioned parameters. Methods. We designed a 14-month prospective longitudinal study in 3 cohorts (ie, infants aged 6-23 months, children aged 6-8 years, and women aged 15-25 years) in the Taabo health demographic surveillance system located in south-central Côte d'Ivoire. Parasitological, hematological, and micronutrient data were obtained from repeated cross-sectional surveys, utilizing standardized, quality-controlled methods. Results. We found that young age, Plasmodium and Schistosoma infections, cellular iron deficiency, and stunting were significantly negatively associated with hemoglobin concentration. Moreover, iron status biomarkers (ie, ferritin and soluble transferrin receptor) were significantly associated with inflammatory parameters. Conclusions. Based on our results, effective prevention and control measures that target parasitic diseases and iron deficiency are needed. These measures might include the distribution of long-lasting insecticidal nets, intermittent preventive treatment for malaria, regular anthelmintic drug administration, and improved intake of bioavailable iron, coupled with health and nutritional education and improved hygiene, water, and sanitatio

    Sedimentation rates in the central lake constance determined with210Pb and137Cs

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    Sediment cores from central Lake Constance were dated with210Pb and137Cs. A sedimentation rate of (0.11±0.02) g·cm-2·y-1 was determined with the210Pb method.137Cs measurements revealed sedimentation rates of (0.11±0.01) g·cm-2·y-1 and (0.08±0.01) g·cm-2·y-1 respectively for two different cores sampled at the same location. The lower Cs-dated value indicates incomplete core recovery and demonstrates the sensitivity of this simple dating method to small losses of material at the water/sediment interface. An unambiguous application of the137Cs method is, therefore, only possible if complete core recovery is ensured. Sedimentation rates based on particulate matter, collected in sediment traps at various water depths, agree with the results of the radioisotope methods. Estimates of 30-125 days residence times for suspended particulate matter were calculated from7Be measurements. © 1987 Birkhäuser Verlag

    Interactions and potential implications of Plasmodium falciparum-hookworm coinfection in different age groups in south-central Côte d'Ivoire

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    BACKGROUND: Given the widespread distribution of Plasmodium and helminth infections, and similarities of ecological requirements for disease transmission, coinfection is a common phenomenon in sub-Saharan Africa and elsewhere in the tropics. Interactions of Plasmodium falciparum and soil-transmitted helminths, including immunological responses and clinical outcomes of the host, need further scientific inquiry. Understanding the complex interactions between these parasitic infections is of public health relevance considering that control measures targeting malaria and helminthiases are going to scale.METHODOLOGY: A cross-sectional survey was carried out in April 2010 in infants, young school-aged children, and young non-pregnant women in south-central Côte d'Ivoire. Stool, urine, and blood samples were collected and subjected to standardized, quality-controlled methods. Soil-transmitted helminth infections were identified and quantified in stool. Finger-prick blood samples were used to determine Plasmodium spp. infection, parasitemia, and hemoglobin concentrations. Iron, vitamin A, riboflavin, and inflammation status were measured in venous blood samples.PRINCIPAL FINDINGS: Multivariate regression analysis revealed specific association between infection and demographic, socioeconomic, host inflammatory and nutritional factors. Non-pregnant women infected with P. falciparum had significantly lower odds of hookworm infection, whilst a significant positive association was found between both parasitic infections in 6- to 8-year-old children. Coinfected children had lower odds of anemia and iron deficiency than their counterparts infected with P. falciparum alone.CONCLUSIONS/SIGNIFICANCE: Our findings suggest that interaction between P. falciparum and light-intensity hookworm infections vary with age and, in school-aged children, may benefit the host through preventing iron deficiency anemia. This observation warrants additional investigation to elucidate the mechanisms and consequences of coinfections, as this information could have important implications when implementing integrated control measures against malaria and helminthiases

    Micronutrient fortification of food and its impact on woman and child health: A systematic review

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    Background: Vitamins and minerals are essential for growth and metabolism. The World Health Organization estimates that more than 2 billion people are deficient in key vitamins and minerals. Groups most vulnerable to these micronutrient deficiencies are pregnant and lactating women and young children, given their increased demands. Food fortification is one of the strategies that has been used safely and effectively to prevent vitamin and mineral deficiencies.Methods: A comprehensive search was done to identify all available evidence for the impact of fortification interventions. Studies were included if food was fortified with a single, dual or multiple micronutrients and impact of fortification was analyzed on the health outcomes and relevant biochemical indicators of women and children. We performed a meta-analysis of outcomes using Review Manager Software version 5.1.Results: Our systematic review identified 201 studies that we reviewed for outcomes of relevance. Fortification for children showed significant impacts on increasing serum micronutrient concentrations. Hematologic markers also improved, including hemoglobin concentrations, which showed a significant rise when food was fortified with vitamin A, iron and multiple micronutrients. Fortification with zinc had no significant adverse impact on hemoglobin levels. Multiple micronutrient fortification showed non-significant impacts on height for age, weight for age and weight for height Z-scores, although they showed positive trends. The results for fortification in women showed that calcium and vitamin D fortification had significant impacts in the post-menopausal age group. Iron fortification led to a significant increase in serum ferritin and hemoglobin levels in women of reproductive age and pregnant women. Folate fortification significantly reduced the incidence of congenital abnormalities like neural tube defects without increasing the incidence of twinning. The number of studies pooled for zinc and multiple micronutrients for women were few, though the evidence suggested benefit. There was a dearth of evidence for the impact of fortification strategies on morbidity and mortality outcomes in women and children.Conclusion: Fortification is potentially an effective strategy but evidence from the developing world is scarce. Programs need to assess the direct impact of fortification on morbidity and mortality
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