493 research outputs found

    Correlates of light and moderate-to-vigorous objectively measured physical activity in four-year-old children

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    Correlates of physical activity (PA) are hypothesized to be context and behaviour specific, but there is limited evidence of this in young children. The aim of the current study is to investigate associations between personal, social and environmental factors and objectively measured light and moderate-to-vigorous PA (LPA and MVPA, respectively) in four-year-old children.Cross-sectional data were used from the Southampton Women's Survey, a UK population-based longitudinal study. Four-year old children (n = 487, 47.0% male) had valid PA data assessed using accelerometry (Actiheart) and exposure data collected with a validated maternal questionnaire (including data on child personality, family demographics, maternal behaviour, rules and restrictions, and perceived local environment). Linear regression modelling was used to analyse associations with LPA and MVPA separately, interactions with sex were explored.LPA minutes were greater in children whose mothers reported more PA (vs. inactive: regression coefficient±standard error: 6.70±2.94 minutes), and without other children in the neighbourhood to play with (-6.33±2.44). MVPA minutes were greater in children with older siblings (vs. none: 5.81±2.80) and those whose mothers used active transport for short trips (vs. inactive: 6.24±2.95). Children accumulated more MVPA in spring (vs. winter: 9.50±4.03) and, in boys only, less MVPA with availability of other children in the neighbourhood (-3.98±1.70).Young children's LPA and MVPA have differing associations with a number of social and environmental variables. Interventions targeting PA promotion in young children outside of formal care settings should consider including intensity specific factors

    A preliminary investigation into the apparent abhesive effect of stearic acid on cured silicone elastomer

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    The effect of addition of small amounts of stearic acid on the adhesive properties of polydimethylsiloxane (PDMS) was investigated. Stearic acid reduced the peel strength of bonded aluminium samples with the joint weakening effect increasing with increased loadings. Surface analysis of the peeled surfaces was carried out using XPS, SSIMS and FTIR. This showed that stearic acid did not form a weak boundary layer at the metal-polymer interface as would traditionally be expected. Local Force Microscopy confirmed this, as the surface adhesion of the PDMS increased, rather than decreased, on addition of stearic acid

    The Role of Translation Initiation Regulation in Haematopoiesis

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    Organisation of RNAs into functional subgroups that are translated in response to extrinsic and intrinsic factors underlines a relatively unexplored gene expression modulation that drives cell fate in the same manner as regulation of the transcriptome by transcription factors. Recent studies on the molecular mechanisms of inflammatory responses and haematological disorders indicate clearly that the regulation of mRNA translation at the level of translation initiation, mRNA stability, and protein isoform synthesis is implicated in the tight regulation of gene expression. This paper outlines how these posttranscriptional control mechanisms, including control at the level of translation initiation factors and the role of RNA binding proteins, affect hematopoiesis. The clinical relevance of these mechanisms in haematological disorders indicates clearly the potential therapeutic implications and the need of molecular tools that allow measurement at the level of translational control. Although the importance of miRNAs in translation control is well recognised and studied extensively, this paper will exclude detailed account of this level of control

    Associations of gestational glycemia and prepregnancy adiposity with offspring growth and adiposity in an Asian population

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    Background: maternal obesity and hyperglycemia increase risk of obesity and diabetes in offspring later in life.Objective: we examined the relation between gestational glycemia and prepregnancy body mass index (ppBMI) with offspring growth in an Asian mother-offspring cohort.Design: pregnant mothers undertook a 75-g 2-h oral-glucose-tolerance test at 26–28 wk of gestation. In 937 singleton offspring, ?9 serial measurements of weight and length were obtained from birth until 36 mo of age.Results: gestational fasting plasma glucose (FPG) was positively associated with birth weight (B: 0.17; 95% CI: 0.10, 0.24; P < 0.001) and birth BMI (B: 0.15; 95% CI: 0.06, 0.40; P = 0.001) but not at ?3 mo of age. In contrast, maternal ppBMI was positively associated with birth variables and conditional growth in weight and BMI in the first 36 mo of life. However, gestational FPG and prepregnancy obesity status interacted significantly for the association with offspring growth and overweight status in the first 36 mo of life (P-interaction < 0.01). In nonobese mothers, each unit increase in gestational FPG was associated with increased offspring weight (B: 0.08; 95% CI: 0.008, 0.16; P = 0.03) and BMI (B: 0.08; 95% CI: 0.003, 0.15; P = 0.04) as well as increased risk of overweight in the first 36 mo of life (OR: 1.36; 95% CI: 1.10, 1.68). However, in obese mothers, each unit increase in gestational FPG was associated with decreased offspring weight (B: ?0.01; 95% CI: ?0.02, ?0.003) and BMI (B: ?0.008; 95% CI: ?0.01, ?0.002) velocity (P < 0.01 for both) and decreased risk of overweight (OR: 0.59; 95% CI: 0.41, 0.86) in the first 36 mo of life.Conclusions: prepregnancy adiposity was associated with offspring growth in early childhood. Although pooled analyses showed no demonstrable difference by 3 mo of age, there were contrasting and opposite associations of gestational glycemia with weight and BMI in the first 36 mo of life in offspring of nonobese and obese mothers separately. This study was registered at clinicaltrials.gov as NCT0117487

    Model of the W3(OH) environment based on data for both maser and 'quasi-thermal' methanol lines

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    In studies of the environment of massive young stellar objects, recent progress in both observations and theory allows a unified treatment of data for maser and 'quasi-thermal' lines. Interferometric maser images provide information on the distribution and kinematics of masing gas on small spatial scales. Observations of multiple masing transitions provide constraints on the physical parameters. Interferometric data on 'quasi-thermal' molecular lines permits an investigation of the overall distribution and kinematics of the molecular gas in the vicinity of young stellar objects, including those which are deeply embedded. Using multiple transitions of different molecules, one can obtain good constraints on the physical and chemical parameters. Combining these data enables the construction of unified models, which take into account spatial scales differing by orders of magnitude. Here we present such a combined analysis of the environment around the ultracompact HII region in W3(OH). This includes the structure of the methanol masing region, physical structure of the near vicinity of W3(OH), detection of new masers in the large-scale shock front and embedded sources in the vicinity of the TW young stellar object.Comment: To appear in the Proceedings of the 2004 European Workshop: "Dense Molecular Gas around Protostars and in Galactic Nuclei", Eds. Y.Hagiwara, W.A.Baan, H.J. van Langevelde, 2004, a special issue of ApSS, Kluwe

    Infant feeding practices in a multi-ethnic Asian cohort: the GUSTO study

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    The optimal introduction of complementary foods provides infants with nutritionally balanced diets and establishes healthy eating habits. The documentation of infant feeding practices in multi-ethnic Asian populations is limited. In a Singapore cohort study (GUSTO), 842 mother-infant dyads were interviewed regarding their feeding practices when the infants were aged 9 and 12 months. In the first year, 20.5% of infants were given dietary supplements, while 5.7% took probiotics and 15.7% homeopathic preparations. At age 9 months, 45.8% of infants had seasonings added to their foods, increasing to 56.3% at 12 months. At age 12 months, 32.7% of infants were given blended food, although 92.3% had begun some form of self-feeding. Additionally, 87.4% of infants were fed milk via a bottle, while a third of them had food items added into their bottles. At both time points, more than a third of infants were provided sweetened drinks via the bottle. Infants of Indian ethnicity were more likely to be given dietary supplements, have oil and seasonings added to their foods and consumed sweetened drinks from the bottle (p < 0.001). These findings provide a better understanding of variations in infant feeding practices, so that healthcare professionals can offer more targeted and culturally-appropriate advice

    Ethnic differences translate to inadequacy of high-risk screening for gestational diabetes mellitus in an Asian population: a cohort study

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    Background: universal and high-risk screening for gestational diabetes mellitus (GDM) has been widely studied and debated. Few studies have assessed GDM screening in Asian populations and even fewer have compared Asian ethnic groups in a single multi-ethnic population.Methods: 1136 pregnant women (56.7% Chinese, 25.5% Malay and 17.8% Indian) from the Growing Up in Singapore Towards healthy Outcomes (GUSTO) birth cohort study were screened for GDM by 75-g oral glucose tolerance test (OGTT) at 26–28 weeks of gestation. GDM was defined using the World Health Organization (WHO) criteria. High-risk screening is based on the guidelines of the UK National Institute for Health and Clinical Excellence.Results: universal screening detected significantly more cases than high-risk screening [crude OR 2.2 (95% CI 1.7-2.8)], particularly for Chinese women [crude OR = 3.5 (95% CI 2.5-5.0)]. Pre-pregnancy BMI > 30 kg/m2 (adjusted OR = 3.4, 95% CI 1.5-7.9) and previous GDM history (adjusted OR = 6.6, 95% CI 1.2-37.3) were associated with increased risk of GDM in Malay women while GDM history was the only significant risk factor for GDM in Chinese women (adjusted OR = 4.7, 95% CI 2.0-11.0).Conclusion: risk factors used in high-risk screening do not sufficiently predict GDM risk and failed to detect half the GDM cases in Asian women. Asian women, particularly Chinese, should be screened to avoid under-diagnosis of GDM and thereby optimize maternal and fetal outcome

    Flavor Changing Neutral Currents involving Heavy Quarks with Four Generations

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    We study various FCNC involving heavy quarks in the Standard Model (SM) with a sequential fourth generation. After imposing BXsγB\to X_s\gamma, BXsl+lB\to X_sl^+l^- and ZbbˉZ\to b\bar{b} constraints, we find B(Zsbˉ+sˉb){\cal B}(Z\to s\bar{b}+\bar{s}b) can be enhanced by an order of magnitude to 10710^{-7}, while tcZ,cHt\to cZ, cH decays can reach 10610^{-6}, which are orders of magnitude higher than in SM. However,these rates are still not observable for the near future.With the era of LHC approaching, we focus on FCNC decays involving fourth generation bb^\prime and tt^\prime quarks. We calculate the rates for loop induced FCNC decays bbZ,bH,bg,bγb^\prime\to bZ, bH, bg, b\gamma, as well as t^\prime\to tZ,\tH, tg, t\gamma. If Vcb|V_{cb'}| is of order Vcb0.04|V_{cb}| \simeq 0.04, tree level bcWb^\prime\to cW decay would dominate, posing a challenge since bb-tagging is less effective. For VcbVcb|V_{cb'}| \ll |V_{cb}|, btWb'\to tW would tend to dominate, while btWb'\to t^\prime W^* could also open for heavier bb', leading to thepossibility of quadruple-WW signals via bbˉbbˉW+WW+Wb'\bar b'\to b\bar b W^+W^-W^+W^-. The FCNC bbZ,bHb'\to bZ, bH decays could still dominate if mbm_{b'} is just above 200 GeV. For the case of tt', ingeneral tbWt^\prime\to bW would be dominant, hence it behaves like a heavy top. For both bb' and tt', except for the intriguing light bb' case, FCNC decays are in the 10410210^{-4} -10^{-2} range, and are quite detectable at the LHC.For a possible future ILC, we find the associated production of FCNC e+ebsˉe^+e^-\to b\bar s, tcˉt\bar c are below sensitivity, while e+ebbˉe^+e^-\to b^\prime\bar b andttˉt^\prime\bar t can be better probed.Tevatron Run-II can still probe the lighter bb' or tt' scenario. LHC would either discover the fourth generation and measure the FCNC rates, or rule out the fourth generation conclusively.Comment: 31 pages, 15 eps figures, version to appear in JHE

    Determinants of the maternal 25-hydroxyvitamin D response to vitamin D supplementation during pregnancy

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    Context: Current approaches to antenatal vitamin D supplementation do not account for interindividual differences in 25-hydroxyvitamin D (25(OH)D) response.Objective: We assessed which maternal and environmental characteristics were associated with 25(OH)D after supplementation with cholecalciferol.Design: Within-randomization-group analysis of participants in the Maternal Vitamin D Osteoporosis Study trial of vitamin D supplementation in pregnancy.Setting: Hospital antenatal clinics.Participants: A total of 829 pregnant women (422 placebo, 407 cholecalciferol). At 14 and 34 weeks of gestation, maternal anthropometry, health, and lifestyle were assessed and 25(OH)D measured. Compliance was determined using pill counts at 19 and 34 weeks.Interventions: 1000 IU/d of cholecalciferol or matched placebo from 14 weeks of gestation until delivery.Main Outcome Measure: 25(OH)D at 34 weeks, measured in a single batch (Diasorin Liaison).Results: 25(OH)D at 34 weeks of gestation was higher in the women randomized to vitamin D (mean [SD], 67.7 [21.3] nmol/L) compared with placebo (43.1 [22.5] nmol/L; P &lt; .001). In women randomized to cholecalciferol, higher pregnancy weight gain from 14 to 34 weeks of gestation (kg) (? = ?0.81 [95% confidence interval ?1.39, ?0.22]), lower compliance with study medication (%) (? = ?0.28 [?0.072, ?0.48]), lower early pregnancy 25(OH)D (nmol/L) (? = 0.28 [0.16, 0.40]), and delivery in the winter vs the summer (? = ?10.5 [?6.4, ?14.6]) were independently associated with lower 25(OH)D at 34 weeks of gestation.Conclusions: Women who gained more weight during pregnancy had lower 25(OH)D in early pregnancy and delivered in winter achieved a lower 25(OH)D in late pregnancy when supplemented with 1000 IU/d cholecalciferol. Future studies should aim to determine appropriate doses to enable consistent repletion of 25(OH)D during pregnancy.<br/
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