Assessment of the sustainability of the iodine-deficiency disorders control program in Lesotho

BACKGROUND: Evaluation of the sustainability of iodine-deficiency disorders control programs guarantees successful and sustained virtual elimination of iodine deficiency. The Lesotho universal salt iodization legislation was enacted in 2000 as an iodine-deficiency disorders control program and has never been evaluated. OBJECTIVES: To assess the sustainability of the salt iodization program in Lesotho, 2 years after promulgation of the universal salt iodization legislation. METHODS: The proportion to population size method of sampling was used in 2002 to select 31 clusters in all ecological zones and districts of Lesotho. In each cluster, 30 women were selected to give urine and salt samples and 30 schoolchildren to give urine samples. The salt samples were analyzed by the iodometric titration method, and the ammonium persulfate method was used to analyze the urine samples. The chairperson of the iodine-deficiency disorders control program was interviewed on programmatic indicators of sustainability. SAS software was used for statistical analysis of the data. RESULTS: The urinary iodine concentrations of very few children (10.1% and 21.5%) and women (9.8% and 17.9%) were lower than 50 microg/L and 100 microg/L, respectively. At the household level, 86.9% of the households used adequately iodized salt. Only four indicators of sustainability have been attained by the salt iodization program in Lesotho. CONCLUSIONS; Iodine-deficiency disorders have been eliminated as a public health problem in Lesotho, but this elimination is not sustainable. Effective regular monitoring of salt iodine content at all levels, with special attention to iodization of coarse salt, is recommended, together with periodic evaluation of the iodization program.     

Iron-Based Nanoparticles for Toxic Organic Degradation: Silica Platform and Green Synthesis

Iron and iron oxide nanoparticles (NPs) are finding wide applications for the remediation of various toxic chloro-organic compounds (such as trichloroethylene, TCE), via reductive and oxidative processes. In this study, Fe NPs (30-50 nm) are synthesized by reduction from ferric ions immobilized (by ion exchange) on a platform (two types of sulfonated silica particles), in order to prevent the NP agglomeration. Next, the Fe NPs are oxidized and their effectiveness for the oxidative dechlorination of TCE via the heterogeneous decomposition of hydrogen peroxide to OH? on the surface of the iron oxide NPs was demonstrated. For the reductive approach, the use of ascorbic acid as a "green" reducing agent in conjunction with a secondary metal (Pd) inhibits NP oxidation and agglomeration through surface adsorbed species. The Fe/Pd NPs have been successfully applied for the dechlorination of TCE (k(SA), surface-area normalized reaction rate, = 8.1 ×10(-4) L/m(2)h).     

Heavy Metal Removal and Neutralization of Acid Mine Waste Water ‐ Kinetic Study

The influence of the apatite on the efficiency of neutralization and on heavy metal removal of acid mine waste water has been studied. The analysis of the treated waste water samples with apatite has shown an advanced purification, the concentration of the heavy metals after the treatment of the waste water with apatite being 25 to 1000 times less than the Maximum Concentration Limits admitted by European Norms (NTPA 001/2005). In order to establish the macro‐kinetic mechanism in the neutralization process, the activation energy, Ea, and the kinetic parameters, rate coefficient of reaction, k_r, and k_t were determined from the experimental results obtained in “ceramic ball‐mill” reactor. The obtained values of the activation energy Ea >> 42 kJ mol^?1 (e.g. Ea = 115.50 ± 7.50 kJ mol^?1 for a conversion of sulphuric acid η_H2SO4 = 0.05, Ea = 60.90 ± 9.50 kJ mol^?1 for η ^H2SO4 = 0.10 and Ea = 55.75 ± 10.45 kJ mol^‐1 for η ^H2SO4 = 0.15) suggest that up to a conversion of H2SO4 equal 0.15 the global process is controlled by the transformation process, adsorption followed by reaction, which means surface‐controlled reactions. At a conversion of sulphuric acid η ^H2SO4 > 0.15, the obtained values of activation energy Ea < 42 kJ mol^‐1 (e.g. Ea = 37.55 ± 4.05 kJ mol^‐1 for η ^H2SO4 = 0.2, Ea = 37.54 ± 2.54 kJ mol^‐1 for η ^H2SO4 = 0.3 and Ea = 37.44 ± 2.90 kJ mol^‐1 for η ^H2SO4 = 0.4) indicate diffusion‐controlled processes. This means a combined process model, which involves the transfer in the liquid phase followed by the chemical reaction at the surface of the solid. Kinetic parameters as rate coefficient of reaction, kr with values ranging from (5.02 ± 1.62) 10‐4 to (8.00 ± 1.55) 10‐4 (s^‐1) and transfer coefficient, kt, ranging from (8.40 ± 0.50) 10‐5 to (10.42 ± 0.65) 10‐5 (m s^‐1) were determined.     

Adolescent male rats exposed to social defeat exhibit altered anxiety behavior and limbic monoamines as adults.

Social stress in adolescence is correlated with emergence of psychopathologies during early adulthood. In this study, the authors investigated the impact of social defeat stress during mid-adolescence on adult male brain and behavior. Adolescent male Sprague–Dawley rats were exposed to repeated social defeat for 5 days while controls were placed in a novel empty cage. When exposed to defeat-associated cues as adults, previously defeated rats showed increased risk assessment and behavioral inhibition, demonstrating long-term memory for the defeat context. However, previously defeated rats exhibited increased locomotion in both elevated plus-maze and open field tests, suggesting heightened novelty-induced behavior. Adolescent defeat also affected adult monoamine levels in stress-responsive limbic regions, causing decreased medial prefrontal cortex dopamine, increased norepinephrine and serotonin in the ventral dentate gyrus, and decreased norepinephrine in the dorsal raphe. Our results suggest that adolescent social defeat produces both deficits in anxiety responses and altered monoaminergic function in adulthood. This model offers potential for identifying specific mechanisms induced by severe adolescent social stress that may contribute to increased adult male vulnerability to psychopathology. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Thermal stability against reduction of LaMn1−yCoyO3 perovskites

Thermal and reduction-oxidation stability of substituted LaMn_1−yCo_yO₃ perovskite-type oxides (0.0 ≤ y_Co ≤ 1.0) prepared by the citrate route have been studied by means of surface area, X-ray diffraction, FTIR spectroscopy and magnetic properties. The perovskite orthorhombic structure is found for y_Co ≤ 0.5, with the exception of y_Co = 0.1, which corresponds better to rhombohedral LaMnO_3.15. For y_Co > 0.5 the diffraction profiles are quite similar to the cobaltite’s rhombohedral structure. Magnetic iso-field studies (ZFC-FC) reveal that, for y_Co ≤ 0.50, the system presents an antiferromagnetic canted-like ordering of the Mn/Co sublattice, in which the presence of divalent Co ion creates Mn³⁺-Mn⁴⁺ pairs that interact ferromagnetically through the oxygen orbital. This interpretation is confirmed by the magnetization loops, in which the magnetic moment increases when substituting Mn for Co. Therefore, the general trend is: for y_Co ≤ 0.5, the Co ions are inserted in the manganite structure and for y_Co > 0.5, the Mn ions are inserted in cobaltite structure. The enhancement of the ferromagnetic properties and the thermal stability against reduction for y_Co = 0.5 is attributed to optimized Co²⁺-Mn⁴⁺ interactions.     

Some metal compounds in the phase of crosslinked ionic polymer—precursors for new sorbents and catalysts

A commercial crosslinked ionic polymer AV‐17 containing ? N(CH₃)₃Cl groups was used. The common compounds of Bi(III) and Al(III); Bi(III) and Cr(III); Bi(III) and Fe(III); Bi(III) and FeOOH and of three components—Bi(III), Fe(III), and Cr(III); Bi(III), FeOOH, and Cr(III) were obtained in the AV‐17 polymer phase and investigated using scanning electron microscopy, powder X‐ray diffraction, thermogravimetric analysis, and Fourier‐transform infrared spectroscopy. It was shown that metal‐containing compounds were concentrated on the surface of the polymer granules. The compounds were in the crystalline (BiOCl) or amorphous (jarosites and oxihydroxides) state. The morphology and composition of the metal‐containing ultra dispersed particles were different on the surface and in the volume of the polymer granule. Most of the metal‐containing compounds were in the form of pseudo spherical particles, but compounds containing Bi(III) and FeOOH in the volume of AV‐17 granule, were in the form of clew of nanometer fibers. Thermogravimetric analysis (in an N₂ atmosphere) in the range 24–1000°C of the metallic compounds containing polymer was also carried out. The metal‐containing polymer samples were stable up to 120°C. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Cyclic Stretch Induces Inducible Nitric Oxide Synthase and Soluble Guanylate Cyclase in Pulmonary Artery Smooth Muscle Cells

In the pulmonary vasculature, mechanical forces such as cyclic stretch induce changes in vascular signaling, tone and remodeling. Nitric oxide is a potent regulator of soluble guanylate cyclase (sGC), which drives cGMP production, causing vasorelaxation. Pulmonary artery smooth muscle cells (PASMCs) express inducible nitric oxide synthase (iNOS), and while iNOS expression increases during late gestation, little is known about how cyclic stretch impacts this pathway. In this study, PASMC were subjected to cyclic stretch of 20% amplitude and frequency of 1 Hz for 24 h and compared to control cells maintained under static conditions. Cyclic stretch significantly increased cytosolic oxidative stress as compared to static cells (62.9 ± 5.9% vs. 33.3 ± 5.7% maximal oxidation), as measured by the intracellular redox sensor roGFP. Cyclic stretch also increased sGCβ protein expression (2.5 ± 0.9-fold), sGC activity (1.5 ± 0.2-fold) and cGMP levels (1.8 ± 0.2-fold), as well as iNOS mRNA and protein expression (3.0 ± 0.9 and 2.6 ± 0.7-fold, respectively) relative to control cells. An antioxidant, recombinant human superoxide dismutase (rhSOD), significantly decreased stretch-induced cytosolic oxidative stress, but did not block stretch-induced sGC activity. Inhibition of iNOS with 1400 W or an iNOS-specific siRNA inhibited stretch-induced sGC activity by 30% and 68% respectively vs. static controls. In conclusion, cyclic stretch increases sGC expression and activity in an iNOS-dependent manner in PASMC from fetal lambs. The mechanism that produces iNOS and sGC upregulation is not yet known, but we speculate these effects represent an early compensatory mechanism to counteract the effects of stretch-induced oxidative stress. A better understanding of the interplay between these two distinct pathways could provide key insights into future avenues to treat infants with pulmonary hypertension.     

Methylcyclohexane dehydrogenation on Rh/γ-Al2O3 catalysts

The influence of the Rh loading on the surface properties and catalytic behaviour of Rh/γ-Al₂O₃ catalysts has been studied. The series of catalysts presents differences in metal dispersion, reducibility, surface composition and catalytic activity. All the data reported suggest that the differences in catalytic behaviour in the methylcyclohexane dehydrogenation reaction can be explained in terms of electron-deficient rhodium clusters, essentially when the metal particle size becomes smaller than 15 Å.     

Iterative algorithm to compute the maximal and stabilising solutions of a general class of discrete-time Riccati-type equations

In this article an iterative method to compute the maximal solution and the stabilising solution, respectively, of a wide class of discrete-time nonlinear equations on the linear space of symmetric matrices is proposed. The class of discrete-time nonlinear equations under consideration contains, as special cases, different types of discrete-time Riccati equations involved in various control problems for discrete-time stochastic systems. This article may be viewed as an addendum of the work of Dragan and Morozan (Dragan, V. and Morozan, T. (2009), ‘A Class of Discrete Time Generalized Riccati Equations’, Journal of Difference Equations and Applications, first published on 11 December 2009 (iFirst), doi: 10.1080/10236190802389381) where necessary and sufficient conditions for the existence of the maximal solution and stabilising solution of this kind of discrete-time nonlinear equations are given. The aim of this article is to provide a procedure for numerical computation of the maximal solution and the stabilising solution, respectively, simpler than the method based on the Newton–Kantorovich algorithm.     

Computer-mediated communication in adolescents with and without a history of specific language impairment (SLI)

The various uses of computer-mediated communication (CMC) are transforming the nature of social interactions and human relations among adolescents. Little is known about engagement of exceptional youth with this technology. The present study investigated the implications of language and social factors for frequency of CMC use and its relationship to adolescent well-being in young people with and without a history of specific language impairment (SLI). Eighty six adolescents with a history of SLI and 90 typically developing 17 year olds participated. Participants completed standardized assessments of psycholinguistic abilities and self-report measures of language motivations and social motivations for CMC use, as well as anxiety and depression. Results indicate that language abilities have a complex relationship with frequency of CMC use; social abilities have a more direct association and are predictive of frequency of CMC use. Both adolescents with SLI and typically developing adolescents were less shy online. No association was obtained between frequency of CMC use and reported emotional symptoms of anxiety and/or depression. It is argued that the characteristics of CMC, in terms of its less stringent language demands and its reduced-cues environment, can provide a medium for positive adaptation of adolescents with communication challenges.