1,473 research outputs found

    Determinants of anemia and hemoglobin concentration in haitian school-aged children

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    Anemia diminishes oxygen transport in the body, resulting in potentially irreversible growth and developmental consequences for children. Limited evidence for determinants of anemia exists for school-aged children. We conducted a cluster randomized controlled trial in Haiti from 2012 to 2013 to test the efficacy of a fortified school snack. Children (N = 1,047) aged 3–13 years were followed longitudinally at three time points for hemoglobin (Hb) concentrations, anthropometry, and bioelectrical impedance measures. Dietary intakes, infectious disease morbidities, and socioeconomic and demographic factors were collected at baseline and endline. Longitudinal regression modeling with generalized least squares and logit models with random effects identified anemia risk factors beyond the intervention effect. At baseline, 70.6% of children were anemic and 2.6% were severely anemic. Stunting increased the odds of developing anemia (adjusted odds ratio [OR]: 1.48, 95% confidence interval [CI]: 1.05–2.08) and severe anemia (adjusted OR: 2.47, 95% CI: 1.30–4.71). Parent-reported vitamin A supplementation and deworming were positively associated with Hb concentrations, whereas fever and poultry ownership showed a negative relationship with Hb concentration and increased odds of severe anemia, respectively. Further research should explore the full spectrum of anemia etiologies in school children, including genetic causes

    Hypergraph Ramsey numbers of cliques versus stars

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    Let Km(3)K_m^{(3)} denote the complete 33-uniform hypergraph on mm vertices and Sn(3)S_n^{(3)} the 33-uniform hypergraph on n+1n+1 vertices consisting of all (n2)\binom{n}{2} edges incident to a given vertex. Whereas many hypergraph Ramsey numbers grow either at most polynomially or at least exponentially, we show that the off-diagonal Ramsey number r(K4(3),Sn(3))r(K_{4}^{(3)},S_n^{(3)}) exhibits an unusual intermediate growth rate, namely, 2clog2nr(K4(3),Sn(3))2cn2/3logn 2^{c \log^2 n} \le r(K_{4}^{(3)},S_n^{(3)}) \le 2^{c' n^{2/3}\log n} for some positive constants cc and cc'. The proof of these bounds brings in a novel Ramsey problem on grid graphs which may be of independent interest: what is the minimum NN such that any 22-edge-coloring of the Cartesian product KNKNK_N \square K_N contains either a red rectangle or a blue KnK_n?Comment: 13 page

    Incorporation of oxygen and nitrogen in ultrathin films of SiO/sub 2 annealed in NO

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    The areal densities of oxygen and nitrogen incorporated into ultrathin films of silicon dioxide during rapid thermal processing in nitric oxide, as well as the regions where these incorporations took place, were determined by combining nuclear reaction analysis and narrow nuclear resonance depth profiling with isotopic enrichment of the processing gas. Oxygen is seen to incorporate in the near-surface and near-interface regions of the oxynitride films, whereas nitrogen is incorporated only in the near-interface regions. The growth of the oxynitride film is very moderate as compared to that of a SiO2 film in dry O2 . The thermal oxynitridation of ultrathin SiO2 films takes place by two mechanisms in parallel: the major part of the NO molecules, which react with the silica, decompose in the near-surface region, the O atoms being exchanged for O atoms preexistent in this region of the SiO2 films; a minor portion of the NO molecules diffuse through the silica film in interstitial sites, without reacting with it, to react at the oxynitride/Si interface

    Distribution of plasma folate forms in hemodialysis patients receiving high daily doses of l-folinic or folic acid

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    Distribution of plasma folate forms in hemodialysis patients receiving high daily doses of l-folinic or folic acid.BackgroundWe have previously reported that a daily oral high dose of l-folinic acid for the treatment of hyperhomocysteinemia in hemodialysis patients does not provide significantly greater reduction in fasting total homocysteine (tHcy) levels than an equimolar dose of folic acid. The present study uses the affinity/HPLC method to analyze the distribution of plasma folate forms in patients who received l-folinic acid versus those who received folic acid. This was done to investigate claims that renal insufficiency is associated with impaired folate interconversion, a stance that is supportive of the premise that tHcy lowering in these patients is more efficacious with folinic acid and other reduced folates, than folic acid.MethodsForty-eight chronic and stable hemodialysis patients were block-randomized, based on their screening predialysis tHcy levels, sex, and dialysis center, into two groups treated for 12 weeks with oral folic acid at 15 mg/day or an equimolar amount (20 mg/day) of oral l-folinic acid. All 48 subjects also received 50 mg/day of oral vitamin B6 and 1 mg/day of oral vitamin B12. Folate distribution was determined in plasma of 46 participants (Folinic acid group, N = 22; Folic acid group, N = 24) by using the affinity/HPLC method, with electrochemical (coulometric) detection.ResultsBoth groups had similar baseline geometric means of plasma total folate and similar folate forms distribution. Following treatment, both groups demonstrated similar marked elevation in plasma total folate (geometric mean of the increase: Folinic acid group, +337 ng/mL; Folic acid group, +312 ng/mL; P = 0.796). In the folinic acid-treated group, practically all of the increase in total folate was due to 5-methyltetrahydrofolate. In the folic acid-treated group 5-methyltetrahydrofolate accounted for 35% of the increase in total folate and the remainder was unmethylated folic acid.ConclusionsData from the present findings suggest that defects in folate absorption or impairment in folate interconversion are not the cause of the persistent hyperhomocysteinemia in hemodialysis patients

    The LIAISE approach for co-designing knowledge on impact assessment tools

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    Impact Assessment (IA) intends to collect evidence on the likely impacts of new policies and thereby minimize unwanted side-effects and maximize the benefits to society. Although it is a requirement in the EC and all OECD countries, the scope and methods vary considerably. Governments have invested considerably in research to support the evidence basis of policy making for sustainable development. However, the general picture shows a gap between the proliferation of IA tools from the scientific community and their actual use in the policy process. The FP7 network of excellence LIAISE (www.liaise- noe.eu) is designed to identify the causes for non-use of IA tools and bridge the gaps between researchers with a generally strong orientation towards their (disciplinary) peers and practitioners who tend to focus on their policy domain and policy problems. LIAISE aims at: 1) understanding of the policy process and the resulting needs for IA knowledge and IA tools; 2) description of IA tools and scientific IA expertise in a standardised way; 3) a shared IA toolbox targeted at the needs of both researchers and practitioners; 4) a shared IA research agenda integrating scientific knowledge gaps and the priorities for the development of new IA knowledge that arise from the future policy agenda; and 5) safeguarding the project results beyond the period of project funding, by developing an institutional setting and a business plan that facilitate the extension of the present consortium towards a broad centre of IA expertise with a structural permanence. A lively interaction between the different communities involved, is essential to realize these objectives. The Berlin Conference is an important opportunity to inform external research groups about the LIAISE approach to bridging the gap between science and policy. Their feedback and views on possible next steps in the further integration of the IA research community are highly valued, as well as their interest to become involved in this process
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