422 research outputs found
Relative effects of postnatal rapid growth and maternal factors on early childhood growth trajectories.
BACKGROUND: A range of postnatal and maternal factors influences childhood obesity, but their relative importance remains unclear. This study aimed to assess the relative impact of postnatal rapid growth and maternal factors on early childhood growth trajectories. SUBJECTS: Secondary longitudinal analysis of pooled data from the Melbourne Infant Feeding Activity and Nutrition Trial (InFANT) Program and the InFANT Extend Program (n = 977) was performed. Children's height and weight were collected at birth, 3, 9, 18, and 36/42 months. Body mass index-for-age and height-for-age z-scores (BAZ, HAZ) were computed using WHO growth standards. Mixed-effect polynomial regression models were fitted to examine BAZ and HAZ trajectories and their determinants. RESULTS: Rapid growth from birth to 3 months, maternal country of birth, and pre-pregnancy BMI were each independently associated with BAZ from 3 to 42 months. Children with rapid growth, those whose mothers were Australian-born, and those whose mothers were overweight/obese pre-pregnancy had higher BAZ from 3 to 42 months. Children with rapid growth had an increase in HAZ growth, but their average HAZ from 3 to 42 months was smaller than children without rapid growth. Children of tall mothers (above average height) had higher HAZ than those of short mothers (below average height). Average HAZ from 3 to 42 months did not differ by maternal country of birth. CONCLUSION: Children who experienced rapid growth from birth to 3 months, whose mothers were Australian-born or whose mothers were overweight/obese pre-pregnancy demonstrated less favourable growth trajectories across early childhood, potentially predispose them for development of future obesity
IMECE2005-81153 MODELING AND CHARACTERIZATION OF DIELECTROPHORETIC ASSEMBLY PROCESS FOR NANOBELTS
ABSTRACT Robust manufacturing methods are needed for nanocomponent assembly, and one must understand the physics to optimize the processing and to develop control schemes to deal with the inherent uncertainty. We are studying field induced assembly of a new class of semiconducting metal oxides -nanobelts -that have been demonstrated for chemical sensing. We have demonstrated the integration of nanobelts with electrodes to make sensors by dielectrophoresis (DEP). The SnO 2 nanobelts (width ~ 100 -300 nm, thickness ~ 30 -40 nm) were suspended in ethanol and introduced into a microchannel, and were assembled across the electrodes. Modeling suggests that attraction should occur at all frequencies over this range. Targeted experiments were performed to quantify surface and material properties for input to the modeling, and FEMLAB simulations were performed to validate the model. The goal of the modeling is to optimize the assembly of nanostructures in a manufacturing process at the wafer-scale. INTRODUCTION A fascinating range of new materials with previously unattainable properties are being developed by nanoscientists. Applications of these new materials include nanowire-based electronics, nanosensors, optical systems, flat panel displays that use carbon nanotubes, high heat flux modified surfaces and biological and biomedical applications. However, the assembly of these nanostructured materials into nanometer-scale device
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Mining Disaggregase Sequence Space to Safely Counter TDP-43, FUS, and α-Synuclein Proteotoxicity.
Hsp104 is an AAA+ protein disaggregase, which can be potentiated via diverse mutations in its autoregulatory middle domain (MD) to mitigate toxic misfolding of TDP-43, FUS, and α-synuclein implicated in fatal neurodegenerative disorders. Problematically, potentiated MD variants can exhibit off-target toxicity. Here, we mine disaggregase sequence space to safely enhance Hsp104 activity via single mutations in nucleotide-binding domain 1 (NBD1) or NBD2. Like MD variants, NBD variants counter TDP-43, FUS, and α-synuclein toxicity and exhibit elevated ATPase and disaggregase activity. Unlike MD variants, non-toxic NBD1 and NBD2 variants emerge that rescue TDP-43, FUS, and α-synuclein toxicity. Potentiating substitutions alter NBD1 residues that contact ATP, ATP-binding residues, or the MD. Mutating the NBD2 protomer interface can also safely ameliorate Hsp104. Thus, we disambiguate allosteric regulation of Hsp104 by several tunable structural contacts, which can be engineered to spawn enhanced therapeutic disaggregases with minimal off-target toxicity
Elevation and cholera: an epidemiological spatial analysis of the cholera epidemic in Harare, Zimbabwe, 2008-2009
BACKGROUND: In highly populated African urban areas where access to clean water is a challenge, water source contamination is one of the most cited risk factors in a cholera epidemic. During the rainy season, where there is either no sewage disposal or working sewer system, runoff of rains follows the slopes and gets into the lower parts of towns where shallow wells could easily become contaminated by excretes. In cholera endemic areas, spatial information about topographical elevation could help to guide preventive interventions. This study aims to analyze the association between topographic elevation and the distribution of cholera cases in Harare during the cholera epidemic in 2008 and 2009. METHODS: We developed an ecological study using secondary data. First, we described attack rates by suburb and then calculated rate ratios using whole Harare as reference. We illustrated the average elevation and cholera cases by suburbs using geographical information. Finally, we estimated a generalized linear mixed model (under the assumption of a Poisson distribution) with an Empirical Bayesian approach to model the relation between the risk of cholera and the elevation in meters in Harare. We used a random intercept to allow for spatial correlation of neighboring suburbs. RESULTS: This study identifies a spatial pattern of the distribution of cholera cases in the Harare epidemic, characterized by a lower cholera risk in the highest elevation suburbs of Harare. The generalized linear mixed model showed that for each 100 meters of increase in the topographical elevation, the cholera risk was 30% lower with a rate ratio of 0.70 (95% confidence interval=0.66-0.76). Sensitivity analysis confirmed the risk reduction with an overall estimate of the rate ratio between 20% and 40%. CONCLUSION: This study highlights the importance of considering topographical elevation as a geographical and environmental risk factor in order to plan cholera preventive activities linked with water and sanitation in endemic areas. Furthermore, elevation information, among other risk factors, could help to spatially orientate cholera control interventions during an epidemic
Differences in infant feeding practices between Chinese-born and Australian-born mothers living in Australia: a cross-sectional study
BACKGROUND: Chinese immigrants are the third largest immigrant group in Australia. Recent qualitative evidence from Victorian Maternal and Child Health nurses indicate that infants of Chinese parents commonly have rapid growth trajectories and that high value is placed on rapid growth and having a fatter child; with low breastfeeding rates and overfeeding of infant formula. The aim of this study was to compare infant feeding practices (breastfeeding, infant formula, other liquids, solids) of Chinese-born and Australian-born mothers living in Australia. METHODS: Using the Australian National Infant Feeding Survey dataset (2010-2011), infant feeding data from Chinese-born mothers (n = 602) were compared with a random sub-sample of Australian-born mothers (n = 602). Group differences on feeding practices were tested using Chi-square or t-tests and the effect of ethnicity on infant feeding behaviours assessed using regression. RESULTS: Compared to infants of Australian-born mothers, infants of Chinese-born mothers were younger when they first consumed infant formula, water-based drinks and fruit juice and older when they first ate solid foods (p < 0.05). Furthermore, infants of Chinese-born mothers were less likely to have ever had cow\u27s milk (OR: 0.37 95%CI:, 0.18-0.78) and solids (0.41, 0.25-0.68); but were more likely to have ever had infant formula (2.19, 1.32-3.62), water (2.45, 1.55-3.87), toddler milk (3.39, 1.60-7.18), water-based drinks (e.g. cordial, soft drink, tea; 2.48, 1.12-5.49), and fruit juice (4.03, 2.50-6.51). Those ≤4 months of age were more likely to have had water-based drinks (7.77, 1.96-30.77) and fruit juice (3.44, 1.14-10.38) (p < 0.05) compared to infants of Australian-born mothers. CONCLUSION: Differences in mothers\u27 early infant feeding practices exist between Chinese-born and Australian-born mothers living in Australia. Better understanding these ethnically patterned infant feeding practices is important for identifying key opportunities to promote best nutrition and growth in early life in different ethnic groups within our population
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