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To assess iodine status among pregnant women in rural Zinder, Niger and to compare their status with the iodine status of school-aged children from the same households.
Seventy-three villages in the catchment area of sixteen health centres were randomly selected to participate in the cross-sectional survey.
Salt iodization is mandatory in Niger, requiring 20–60 ppm iodine at the retail level.
A spot urine sample was collected from randomly selected pregnant women (n 662) and one school-aged child from the same household (n 373). Urinary iodine concentration (UIC) was assessed as an indicator of iodine status in both groups. Dried blood spots (DBS) were collected from venous blood samples of pregnant women and thyroglobulin (Tg), thyroid-stimulating hormone and total thyroxine were measured. Iodine content of household salt samples (n 108) was assessed by titration.
Median iodine content of salt samples was 5·5 ppm (range 0–41 ppm), 98 % had an iodine content <20 ppm. Median (interquartile range) UIC of pregnant women and school-aged children was 69·0 (38·1–114·3) and 100·9 (61·2–163·2) µg/l, respectively. Although nearly all pregnant women were euthyroid, their median (interquartile range) DBS-Tg was 34·6 (23·9–49·7) µg/l and 38·4 % had DBS-Tg>40 µg/l.
In this region of Niger, most salt is inadequately iodized. UIC in pregnant women indicated iodine deficiency, whereas UIC of school-aged children indicated marginally adequate iodine status. Thus, estimating population iodine status based solely on monitoring of UIC among school-aged children may underestimate the risk of iodine deficiency in pregnant women.
As has been found in previous studies, the labor market performance of individuals is often affected by demographic determinants like cohort size, age, marriage status and family size. While most of this analysis was studied for earnings, the paper investigates the issue for labor mobility. Mobility is measured here by the number of new employers and the frequency of unemployment of an individual in a particular period. Given the discrete nature of the data, the ordinal probit model and the censored Poisson as the censored negative binomial model was estimated. Since the choice of the statistical model is not clear a priori, various model comparisons are carried out and some new pseudo-R2 measures are proposed and used in the analysis. Results indicate that demographic determinants matter for labor mobility.
The non-stationarity of many macroeconomic time-series has lead to an increased demand for economic models that are able to generate fragile equilibria. For instance, the natural unemployment rate is allowed to shift over time depending on past unemployment. Actually, many European unemployment series seem to exhibit a unit root or persistence. This view is questioned in the paper using German data on unemployment. A new class of time-series models, the fractionally integrated ARMA model, that allows the difference parameter to take real values, enables the researcher to separate long memory and short memory in the data. It is shown that using this approach the unit root hypothesis is rejected but unemployment exhibits long memory.
In order to ensure the quality of the source catalogue derived from the SASS processing an automatic as well as a visual screening procedure was applied to 1378 survey fields. Most (94%) of the 18,811 sources were confirmed by this screening process. The rest is flagged for various reasons. Broad band images are available for a subset of the flagged sources. Details of the screening process can be found at www.rosat.mpe-garching.mpg.de/survey/rass-bsc/doc.html.
Provision and need for mental health services among military personnel are a major concern across nations. Two recent comparisons suggest higher rates of mental disorders in US and UK military personnel compared with civilians. However, these findings may not apply to other nations. Previous studies have focused on the overall effects of military service rather than the separate effects of military service and deployment. This study compared German military personnel with and without a history of deployment to sociodemographically matched civilians regarding prevalence and severity of 12-month DSM-IV mental disorders.
1439 deployed soldiers (DS), 779 never deployed soldiers (NS) and 1023 civilians were assessed with an adapted version of the Munich Composite International Diagnostic interview across the same timeframe. Data were weighted using propensity score methodology to assure comparability of the three samples.
Compared with adjusted civilians, the prevalence of any 12-month disorder was lower in NS (OR: 0.7, 95% CI: 0.5–0.99) and did not differ in DS. Significant differences between military personnel and civilians regarding prevalence and severity of individual diagnoses were only apparent for alcohol (DS: OR: 0.3, 95% CI: 0.1–0.6; NS: OR: 0.2, 95% CI: 0.1–0.6) and nicotine dependence (DS: OR: 0.5, 95% CI: 0.3–0.6; NS: OR: 0.5, 95% CI: 0.3–0.7) with lower values in both military samples. Elevated rates of panic/agoraphobia (OR: 2.7, 95% CI: 1.4–5.3) and posttraumatic stress disorder (OR: 3.2, 95% CI: 1.3–8.0) were observed in DS with high combat exposure compared with civilians.
Rates and severity of mental disorders in the German military are comparable with civilians for internalising and lower for substance use disorders. A higher risk of some disorders is reduced to DS with high combat exposure. This finding has implications for mental health service provision and the need for targeted interventions. Differences to previous US and UK studies that suggest an overall higher prevalence in military personnel might result from divergent study methods, deployment characteristics, military structures and occupational factors. Some of these factors might yield valuable targets to improve military mental health.
The polyphenol quercetin may prevent CVD due to its antihypertensive and vasorelaxant properties. We investigated the effects of quercetin after regular intake on blood pressure (BP) in overweight-to-obese patients with pre-hypertension and stage I hypertension. In addition, the potential mechanisms responsible for the hypothesised effect of quercetin on BP were explored. Subjects (n 70) were randomised to receive 162 mg/d quercetin from onion skin extract powder or placebo in a double-blinded, placebo-controlled cross-over trial with 6-week treatment periods separated by a 6-week washout period. Before and after the intervention, ambulatory blood pressure (ABP) and office BP were measured; urine and blood samples were collected; and endothelial function was measured by EndoPAT technology. In the total group, quercetin did not significantly affect 24 h ABP parameters and office BP. In the subgroup of hypertensives, quercetin decreased 24 h systolic BP by −3·6 mmHg (P=0·022) when compared with placebo (mean treatment difference, −3·9 mmHg; P=0·049). In addition, quercetin significantly decreased day-time and night-time systolic BP in hypertensives, but without a significant effect in inter-group comparison. In the total group and also in the subgroup of hypertensives, vasoactive biomarkers including endothelin-1, soluble endothelial-derived adhesion molecules, asymmetric dimethylarginine, angiotensin-converting enzyme activity, endothelial function, parameters of oxidation, inflammation, lipid and glucose metabolism were not affected by quercetin. In conclusion, supplementation with 162 mg/d quercetin from onion skin extract lowers ABP in patients with hypertension, suggesting a cardioprotective effect of quercetin. The mechanisms responsible for the BP-lowering effect remain unclear.
Antidepressants reduce depressive symptoms in patients with coronary heart disease, but they may be associated with increased mortality. This study aimed to examine whether the use of tricyclic antidepressants (TCA) or selective serotonin reuptake inhibitors (SSRI) is associated with mortality in patients with coronary heart disease, and to determine whether this association is mediated by autonomic function.
A total of 956 patients with coronary heart disease were followed for a mean duration of 7.2 years. Autonomic function was assessed as heart rate variability, and plasma and 24-h urinary norepinephrine.
Of 956 patients, 44 (4.6%) used TCA, 89 (9.3%) used SSRI, and 823 (86.1%) did not use antidepressants. At baseline, TCA users exhibited lower heart rate variability and higher norepinephrine levels compared with SSRI users and antidepressant non-users. At the end of the observational period, 52.3% of the TCA users had died compared with 38.2% in the SSRI group and 37.3% in the control group. The adjusted hazard ratio (HR) for TCA use compared with non-use was 1.74 [95% confidence interval (CI) 1.12–2.69, p = 0.01]. Further adjustment for measures of autonomic function reduced the association between TCA use and mortality (HR = 1.27, 95% CI 0.67–2.43, p = 0.47). SSRI use was not associated with mortality (HR = 1.15, 95% CI 0.81–1.64, p = 0.44).
The use of TCA was associated with increased mortality. This association was at least partially mediated by differences in autonomic function. Our findings suggest that TCA should be avoided in patients with coronary heart disease.
Thin‑film silicon solar cells based on hydrogenated amorphous silicon (a‑Si:H) and hydrogenated microcrystalline silicon (μc‑Si:H) absorber layers are typically deposited using static plasma-enhanced chemical vapor deposition (PECVD) processes. It has been found that the use of very‑high frequencies (VHF) is beneficial for the material quality at high deposition rates when compared to radio-frequency (RF) processes. In the present work a dynamic VHF‑PECVD technique using linear plasma sources is developed. The linear plasma sources facilitate the use of very-high excitation frequencies on large electrode areas without compromising on the homogeneity of the deposition process. It is shown that state-of-the-art a‑Si:H and μc‑Si:H single-junction solar cells can be deposited incorporating intrinsic layers grown dynamically by VHF-PECVD at 0.35 nm/s and 0.95 nm/s, respectively.
The proton bunch-driven plasma wakefield acceleration (PWFA) has been proposed as an approach to accelerate an electron beam to the TeV energy regime in a single plasma section. An experimental program has been recently proposed to demonstrate the capability of proton-driven PWFA by using existing proton beams from the European Organization for Nuclear Research (CERN) accelerator complex. At present, a spare Super Proton Synchrotron (SPS) tunnel, having a length of 600 m, could be used for this purpose. The layout of the experiment is introduced. Particle-in-cell simulation results based on realistic SPS beam parameters are presented. Simulations show that working in a self-modulation regime, the wakefield driven by an SPS beam can accelerate an externally injected ~10 MeV electrons to ~2 GeV in a 10-m plasma, with a plasma density of 7 × 1014 cm−3.
Iron deficiency affects approximately 2 billion people worldwide, especially young women and children. Food fortification with iron is a sustainable approach to alleviate iron deficiency but remains a challenge. Water-soluble compounds with high bioavailability (e.g. the “gold standard” FeSO4) usually cause unacceptable sensory changes in foods, while compounds that are less reactive in food matrices are often less bioavailable. Solubility (and therefore bioavailability) can be improved by increasing the specific surface area (SSA) of the compound, i.e. decreasing its particle size to the nm range. Here, iron oxide-based nanostructured compounds with Mg or Ca are made using scalable flame aerosol technology. Addition of either element increased iron solubility to a level comparable to iron phosphate. Furthermore, these additions lightened the powder color and sensory changes in fruit yoghurt were less prominent than for FeSO4.
Fully amorphous ceramics in the system silicon-carbon-nitrogen were produced with the polymer precursor route using the commercially available polysilazane CerasetTM. Besides their high temperature thermal stability, these ceramics show excellent high temperature creep resistance. Not many investigations have been dedicated to the fracture mechanics of these materials. This paper provides data on toughness measurements utilizing bulk and indentation techniques. The double cantilever beam method (DCB) was used to study crack propagation. To determine the intrinsic toughness, the crack opening displacements (COD) of indentation cracks were determined.
The electrical properties of epitaxial ZnO thin films grown on sapphire substrates by pulsed laser deposition were investigated by temperature dependent Hall measurents. The thin films investigated were grown at different oxygen partial pressures ranging from 10-2 mbar to 1 mbar. The formation of a degenerate layer, determining the low temperature Hall data, depends on the oxygen partial pressure applied during growth. Further, the formation of such a layer can be correlated to the grain size of the samples. The thermal activation energy of dominant donors decreases in tendency with increasing oxygen partial pressure p(O2); it is about 100 meV for p(O2) ≤ 3 × 10-2 mbar and about 30 meV for p(O2) ≥ 0.1 mar. The concentration of donors and compensating acceptors increases with increasing p(O2).
MgxZn1-xO/ZnO/MgxZn1-xO quantum wells (QWs) (0.12 ≤ x ≤ 0.15) have been grown on a-plane sapphire substrates by pulsed laser deposition. The nominal ZnO well layer thickness lies between 1.2 nm and 6 nm. Atomic force microscopy (AFM) investigations at ZnO/MgxZn1−xO heterostructures show the film-like structure of the ZnO layers. Their root mean square surface roughness of ∼ 0.5 nm gives information about the interface roughness in the QWs. AFM results from the MgxZn1−xO barrier layers show the same surface structure and roughness. We confirmed the lateral homogeneity of the Mg distribution in the MgxZn1−xO barrier layers by scanning cathodoluminescence measurements. The QWs show a bright and laterally homogeneous luminescence, suggesting good crystalline quality of the ZnO wells. The measured QW photoluminescence energies agree well with calculated values and display the presence of the quantum-confined Stark effect. As a result of quantum confinement a high-energy shift of the ZnO excitonic photoluminescence of 222 meV is observed in the thinnest QW.
Fe absorption from water-soluble forms of Fe is inversely proportional to Fe status in humans. Whether this is true for poorly soluble Fe compounds is uncertain. Our objectives were therefore (1) to compare the up-regulation of Fe absorption at low Fe status from ferrous sulphate (FS) and ferric pyrophosphate (FPP) and (2) to compare the efficacy of FS with FPP in a fortification trial to increase body Fe stores in Fe-deficient children v. Fe-sufficient children. Using stable isotopes in test meals in young women (n 49) selected for low and high Fe status, we compared the absorption of FPP with FS. We analysed data from previous efficacy trials in children (n 258) to determine whether Fe status at baseline predicted response to FS v. FPP as salt fortificants. Plasma ferritin was a strong negative predictor of Fe bioavailability from FS (P < 0·0001) but not from FPP. In the efficacy trials, body Fe at baseline was a negative predictor of the change in body Fe for both FPP and FS, but the effect was significantly greater with FS (P < 0·01). Because Fe deficiency up-regulates Fe absorption from FS but not from FPP, food fortification with FS may have relatively greater impact in Fe-deficient children. Thus, more soluble Fe compounds not only demonstrate better overall absorption and can be used at lower fortification levels, but they also have the added advantage that, because their absorption is up-regulated in Fe deficiency, they innately ‘target’ Fe-deficient individuals in a population.
Adverse sensory changes prevent the addition of highly bioavailable ferrous sulfate (FeSO4) to most wheat flours. Poorly absorbable reduced Fe powders are commonly used. Encapsulation of FeSO4 can overcome these sensory changes, but the particle size of commercial compounds is too large to be used by flour mills. The first objective of the study was to measure the efficacy in wheat flour of two newly developed Fe compounds, an H-reduced Fe powder (NutraFine™ RS; North America Höganäs High Alloys LLC, Johnstown, PA, USA) and small particle-sized (40 μm) encapsulated FeSO4. As a second objective, the microcapsules were evaluated as a vehicle for iodine fortification. A randomised, double-blind controlled intervention trial was conducted in Kuwaiti women (n 279; aged 18–35 years) with low body Fe stores (serum ferritin (SF) < 25 μg/l) randomly assigned to one of three groups (20 mg Fe as NutraFine™ RS, 10 mg Fe as encapsulated FeSO4 and 150 μg iodine, or no fortification Fe) who consumed wheat-based biscuits 5 d per week. At baseline and 22 weeks, Hb, SF, transferrin receptor, urinary iodine and body Fe stores were measured. Relative to control, mean SF in the encapsulated FeSO4 group increased by 88 % (P < 0·001) and body Fe stores increased from − 0·96 to 2·24 mg/kg body weight (P < 0·001), while NutraFine™ RS did not significantly increase SF or body Fe stores. The median urinary iodine concentration increased from 140 to 213 μg/l (P < 0·01). NutraFine™ RS added at double the amount of Fe as FeSO4 was not efficacious in improving Fe status. The newly developed microcapsules were highly efficacious in improving both Fe stores and iodine status.
There are few data on the prevalence of riboflavin deficiency in sub-Saharan Africa, and it remains unclear whether riboflavin status influences the risk for anaemia. The aims of this study were to: (1) measure the prevalence of riboflavin deficiency in children in south-central Côte d'Ivoire; (2) estimate the riboflavin content of the local diet; and (3) determine if riboflavin deficiency predicts anaemia and/or iron deficiency. In 5- to 15-year-old children (n 281), height, weight, haemoglobin (Hb), whole blood zinc protoporphyrin (ZPP), erythrocyte glutathione reductase activity coefficient (EGRAC), serum retinol, C-reactive protein (CRP) and prevalence of Plasmodium spp. (asymptomatic malaria) and Schistosoma haematobium (bilharziosis) infections were measured. Three-day weighed food records were kept in twenty-four households. Prevalence of anaemia in the sample was 52 %; 59 % were iron-deficient based on an elevated ZPP concentration, and 36 % suffered from iron deficiency anaemia. Plasmodium parasitaemia was found in 49 % of the children. Nineteen percent of the children were infected with S. haematobium. Median riboflavin intake in 5- to 15-year-old children from the food records was 0·42 mg/d, ~47 % of the estimated average requirement for this age group. Prevalence of riboflavin deficiency was 65 %, as defined by an EGRAC value >1·2. Age, elevated CRP and iron deficiency were significant predictors of Hb. Riboflavin-deficient children free of malaria were more likely to be iron deficient (odds ratio; 3·07; 95 % CI 1·12, 8·41). In conclusion, nearly two-thirds of school-age children in south-central Côte d'Ivoire are mildly riboflavin deficient. Riboflavin deficiency did not predict Hb and/or anaemia, but did predict iron deficiency among children free of malaria.
This communication presents the effects of nitrogen pressure on the crystallization behavior of Si3.0B1.1C5.3N3.0 ceramics annealed at 1800 °C for 3 h. Transmission electron microscopy observation reveals that increasing nitrogen pressure results in the retardation of the crystallization process. Besides SiC and Si3N4 nanocrystals, individual large crystallites were also detected. These crystals were composed only of Si and N, and they possessed hexagonal structure with lattice parameters a = 0.737 nm and c = 0.536 nm. Crystallites of this novel phase were more frequently found with increased nitrogen pressure.