41 research outputs found

    GPS based Multi-hop Communication with Localization in Subterranean Wireless Sensor Networks

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    AbstractOur research work proposes Multi-hop Communication with Localization (MCL), a strategy to localize and route information to nodes present in such areas by determining angles and distances of consecutive nodes hop by hop towards the Base Station. Based on the application area, Subterranean Wireless Sensor Networks are specifically designed to detect underground abnormal conditions and reported to the base station. Many protocols use distance between the nodes as one of the criteria for multi-hop communication in the network. It is found to be necessary to know the location of the nodes and the distance between the nodes in many power optimization protocols. But the query of how to attain the distance or the location arises in the same. The main objective here is to design a technique to both localize and transmit data efficiently in subterranean areas. Initially there is a group of nodes deployed in the underground areas all of which bond to a sink that is further connected to the Base Station. It is possible to locate all the nodes through GPS which can be used as a reference in the worst case scenario by the Base Station. The sink node has a Node Transmission Area (NTA) within which a node can be directly recognized by the sink node otherwise it finds the target node through the intermediate nodes. Our empirical work proves the computational method on attaining the performance

    Improving women’s diet quality pre-conceptionally and during gestation: effects on birth weight and prevalence of low birth weight; a randomized controlled efficacy trial in India (Mumbai Maternal Nutrition Project)

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    BACKGROUND: Low birth weight (LBW) is an important public health problem in undernourished populations.OBJECTIVE: We tested whether improving women's dietary micronutrient quality before conception and throughout pregnancy increases birth weight in a high-risk Indian population.DESIGN: The study was a nonblinded, individually randomized controlled trial. The intervention was a daily snack made from green leafy vegetables, fruit, and milk (treatment group) or low-micronutrient vegetables (potato and onion) (control group) from ? 90 d before pregnancy until delivery in addition to the usual diet. Treatment snacks contained 0.69 MJ of energy (controls: 0.37 MJ) and 10-23% of WHO Reference Nutrient Intakes of ?-carotene, riboflavin, folate, vitamin B-12, calcium, and iron (controls: 0-7%). The primary outcome was birth weight.RESULTS: Of 6513 women randomly assigned, 2291 women became pregnant, 1962 women delivered live singleton newborns, and 1360 newborns were measured. In an intention-to-treat analysis, there was no overall increase in birth weight in the treatment group (+26 g; 95% CI: -15, 68 g; P = 0.22). There was an interaction (P &lt; 0.001) between the allocation group and maternal prepregnant body mass index (BMI; in kg/m(2)) [birth-weight effect: -23, +34, and +96 g in lowest (&lt;18.6), middle (18.6-21.8), and highest (&gt;21.8) thirds of BMI, respectively]. In 1094 newborns whose mothers started supplementation ? 90 d before pregnancy (per-protocol analysis), birth weight was higher in the treatment group (+48 g; 95% CI: 1, 96 g; P = 0.046). Again, the effect increased with maternal BMI (-8, +79, and +113 g; P-interaction = 0.001). There were similar results for LBW (intention-to-treat OR: 0.83; 95% CI: 0.66, 1.05; P = 0.10; per-protocol OR = 0.76; 95% CI: 0.59, 0.98; P = 0.03) but no effect on gestational age in either analysis.CONCLUSIONS: A daily snack providing additional green leafy vegetables, fruit, and milk before conception and throughout pregnancy had no overall effect on birth weight. Per-protocol and subgroup analyses indicated a possible increase in birth weight if the mother was supplemented ? 3 mo before conception and was not underweight. This trial was registered at www.controlled-trials.com/isrctn/ as ISRCTN62811278<br/

    Relative motion of transmembrane segments S0 and S4 during voltage sensor activation in the human BKCa channel

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    Large-conductance voltage- and Ca2+-activated K+ (BKCa) channel α subunits possess a unique transmembrane helix referred to as S0 at their N terminus, which is absent in other members of the voltage-gated channel superfamily. Recently, S0 was found to pack close to transmembrane segments S3 and S4, which are important components of the BKCa voltage-sensing apparatus. To assess the role of S0 in voltage sensitivity, we optically tracked protein conformational rearrangements from its extracellular flank by site-specific labeling with an environment-sensitive fluorophore, tetramethylrhodamine maleimide (TMRM). The structural transitions resolved from the S0 region exhibited voltage dependence similar to that of charge-bearing transmembrane domains S2 and S4. The molecular determinant of the fluorescence changes was identified in W203 at the extracellular tip of S4: at hyperpolarized potential, W203 quenches the fluorescence of TMRM labeling positions at the N-terminal flank of S0. We provide evidence that upon depolarization, W203 (in S4) moves away from the extracellular region of S0, lifting its quenching effect on TMRM fluorescence. We suggest that S0 acts as a pivot component against which the voltage-sensitive S4 moves upon depolarization to facilitate channel activation

    Metal-driven Operation of the Human Large-conductance Voltage- and Ca^(2+)-dependent Potassium Channel (BK) Gating Ring Apparatus

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    Large-conductance voltage- and Ca^(2+)-dependent K^+ (BK, also known as MaxiK) channels are homo-tetrameric proteins with a broad expression pattern that potently regulate cellular excitability and Ca^(2+) homeostasis. Their activation results from the complex synergy between the transmembrane voltage sensors and a large (>300 kDa) C-terminal, cytoplasmic complex (the “gating ring”), which confers sensitivity to intracellular Ca^(2+) and other ligands. However, the molecular and biophysical operation of the gating ring remains unclear. We have used spectroscopic and particle-scale optical approaches to probe the metal-sensing properties of the human BK gating ring under physiologically relevant conditions. This functional molecular sensor undergoes Ca^(2+)- and Mg^(2+)-dependent conformational changes at physiologically relevant concentrations, detected by time-resolved and steady-state fluorescence spectroscopy. The lack of detectable Ba^(2+)-evoked structural changes defined the metal selectivity of the gating ring. Neutralization of a high-affinity Ca^(2+)-binding site (the “calcium bowl”) reduced the Ca^(2+) and abolished the Mg^(2+) dependence of structural rearrangements. In congruence with electrophysiological investigations, these findings provide biochemical evidence that the gating ring possesses an additional high-affinity Ca^(2+)-binding site and that Mg^(2+) can bind to the calcium bowl with less affinity than Ca^(2+). Dynamic light scattering analysis revealed a reversible Ca^(2+)-dependent decrease of the hydrodynamic radius of the gating ring, consistent with a more compact overall shape. These structural changes, resolved under physiologically relevant conditions, likely represent the molecular transitions that initiate the ligand-induced activation of the human BK channel

    Healthcare choices in Mumbai slums: A cross-sectional study [version 2; referees: 1 approved, 2 approved with reservations]

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    Background: Informal urban settlements, known as slums, are the home for a large proportion of the world population. Healthcare in these environments is extremely complex, driven by poverty, environmental challenges, and poor access to formal health infrastructures. This study investigated healthcare challenges faced and choices made by slum dwellers in Mumbai, India. Methods: Structured interviews with 549 slum dwellers from 13 slum areas in Mumbai, India, were conducted in order to obtain a population profile of health-related socio-economic and lifestyle factors, disease history and healthcare access. Statistical tools such as multinomial logistic regression were used to examine the association between such factors and health choices. Results: Private providers (or a mixture of public and private) were seen to be preferred by the study population for most health conditions (62% - 90% health consultations), apart from pregnancy (43% health consultations). Community-based services were also preferred to more remote options. Stark differences in healthcare access were observed between well-known conditions, such as minor injuries, pulmonary conditions, and pregnancy and emerging challenges, such as hypertension and diabetes. A number of socio-economic and lifestyle factors were found to be associated with health-related decisions, including choice of provider and expenditure. Conclusions: Better planning and coordination of health services, across public and private providers, is required to address mortality and morbidity in slum communities in India. This study provides insights into the complex landscape of diseases and health providers that slum dwellers navigate when accessing healthcare. Findings suggest that integrated services and public-private partnerships could help address demand for affordable community-based care and progress towards the target of universal health coverage

    Effects of a food-based intervention on markers of micronutrient status among Indian women of low socio-economic status.

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    Intakes of micronutrient-rich foods are low among Indian women of reproductive age. We investigated whether consumption of a food-based micronutrient-rich snack increased markers of blood micronutrient concentrations when compared with a control snack. Non-pregnant women (n 222) aged 14–35 years living in a Mumbai slum were randomised to receive a treatment snack (containing green leafy vegetables, dried fruit and whole milk powder), or a control snack containing foods of low micronutrient content such as wheat flour, potato and tapioca. The snacks were consumed under observation 6 d per week for 12 weeks, compliance was recorded, and blood was collected at 0 and 12 weeks. Food-frequency data were collected at both time points. Compliance (defined as the proportion of women who consumed ? 3 snacks/week) was &gt;85 % in both groups. We assessed the effects of group allocation on 12-week nutrient concentrations using ANCOVA models with respective 0-week concentrations, BMI, compliance, standard of living, fruit and green leafy vegetable consumption and use of synthetic nutrients as covariates. The treatment snack significantly increased ?-carotene concentrations (treatment effect: 47·1 nmol/l, 95 % CI 6·5, 87·7). There was no effect of group allocation on concentrations of ferritin, retinol, ascorbate, folate or vitamin B12. The present study shows that locally sourced foods can be made into acceptable snacks that may increase serum ?-carotene concentrations among women of reproductive age. However, no increase in circulating concentrations of the other nutrients measured was observe
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