115 research outputs found

    Galaxy evolution by color-log(n) type since redshift unity in the Hubble Ultra Deep Field

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    We explore the use of the color-log(n) plane (where n is the global Sersic index) as a tool for subdividing the high redshift galaxy population in a physically-motivated manner. Using a series of volume-limited samples out to z=1.5 in the Hubble Ultra Deep Field (UDF) we confirm the correlation between color-log(n) plane position and visual morphology observed locally and in other high redshift studies in the color and/or structure domain. Via comparison to a low redshift sample from the Millennium Galaxy Catalogue we quantify evolution by color-log(n) type, accounting separately for the specific selection and measurement biases against each. Specifically, we measure decreases in B-band surface brightness of 1.57 +/- 0.22 mag/sq.arcsec and 1.65 +/- 0.22 mag/sq.arcsec for `blue, diffuse' and `red, compact' galaxies respectively between redshift unity and the present day.Comment: 12 pages, 6 figures, to be published in A&A (accepted 29/10/08

    Do Mismatches between Pre- and Post-Natal Environments Influence Adult Physiological Functioning?

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    Purpose: Mismatches between pre- and post-natal environments have implications for disease in adulthood. However, less is known about how this mismatch can affect physiological systems more generally, especially at younger ages. We hypothesised that mismatches between pre- and post-natal environments, as measured by the measures of birthweight and adult leg length, would be associated with poorer biomarker levels across five key physiological systems in young adults. Methods: Data were collected from 923, 36 year-old respondents from the West of Scotland Twenty-07 Study. The biomarkers were: systolic blood pressure (sBP); forced expiratory volume (FEV1); glycated haemoglobin (HbA1c); glomerular filtration rate (eGFR); and gamma- glutamyltransferase (GGT). These biomarkers were regressed against pre-natal conditions (birthweight), post-natal conditions (leg length) and the interaction between pre- and post-natal measures. Sex, childhood socioeconomic position and adult lifestyle characteristics were adjusted for as potential effect modifiers and confounders, respectively. Results: There were no associations between birthweight and leg length and sBP, FEV1, HbA1c, or GGT. Higher birthweight and longer leg length were associated with better kidney function (eGFR). However, there was no evidence for mismatches between birthweight and leg length to be associated with worse sBP, FEV1, HbA1c, eGFR or GGT levels (P>0.05). Conclusions: Our hypothesis that early signs of physiological damage would be present in young adults given mismatches in childhood environments, as measured by growth markers, was not proven. This lack of association could be because age 36 is too young to identify significant trends for future health, or the associations simply not being present. © 2014 Robertson, Benzeval

    Socio-Demographic Patterning of Physical Activity across Migrant Groups in India: Results from the Indian Migration Study

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    OBJECTIVE: To investigate the relationship between rural to urban migration and physical activity (PA) in India. METHODS: 6,447 (42% women) participants comprising 2077 rural, 2,094 migrants and 2,276 urban were recruited. Total activity (MET hr/day), activity intensity (min/day), PA Level (PAL) television viewing and sleeping (min/day) were estimated and associations with migrant status examined, adjusting for the sib-pair design, age, site, occupation, education, and socio-economic position (SEP). RESULTS: Total activity was highest in rural men whereas migrant and urban men had broadly similar activity levels (p<0.001). Women showed similar patterns, but slightly lower levels of total activity. Sedentary behaviour and television viewing were lower in rural residents and similar in migrant and urban groups. Sleep duration was highest in the rural group and lowest in urban non-migrants. Migrant men had considerably lower odds of being in the highest quartile of total activity than rural men, a finding that persisted after adjustment for age, SEP and education (OR 0.53, 95% CI 0.37, 0.74). For women, odds ratios attenuated and associations were removed after adjusting for age, SEP and education. CONCLUSION: Our findings suggest that migrants have already acquired PA levels that closely resemble long-term urban residents. Effective public health interventions to increase PA are needed

    Dynamics of Co-Transcriptional Pre-mRNA Folding Influences the Induction of Dystrophin Exon Skipping by Antisense Oligonucleotides

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    Antisense oligonucleotides (AONs) mediated exon skipping offers potential therapy for Duchenne muscular dystrophy. However, the identification of effective AON target sites remains unsatisfactory for lack of a precise method to predict their binding accessibility. This study demonstrates the importance of co-transcriptional pre-mRNA folding in determining the accessibility of AON target sites for AON induction of selective exon skipping in DMD. Because transcription and splicing occur in tandem, AONs must bind to their target sites before splicing factors. Furthermore, co-transcriptional pre-mRNA folding forms transient secondary structures, which redistributes accessible binding sites. In our analysis, to approximate transcription elongation, a “window of analysis” that included the entire targeted exon was shifted one nucleotide at a time along the pre-mRNA. Possible co-transcriptional secondary structures were predicted using the sequence in each step of transcriptional analysis. A nucleotide was considered “engaged” if it formed a complementary base pairing in all predicted secondary structures of a particular step. Correlation of frequency and localisation of engaged nucleotides in AON target sites accounted for the performance (efficacy and efficiency) of 94% of 176 previously reported AONs. Four novel insights are inferred: (1) the lowest frequencies of engaged nucleotides are associated with the most efficient AONs; (2) engaged nucleotides at 3′ or 5′ ends of the target site attenuate AON performance more than at other sites; (3) the performance of longer AONs is less attenuated by engaged nucleotides at 3′ or 5′ ends of the target site compared to shorter AONs; (4) engaged nucleotides at 3′ end of a short target site attenuates AON efficiency more than at 5′ end

    Macrosomia and large for gestational age in Asia:One size does not fit all

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    Macrosomia, usually defined as infant birth weight of >= 4000 g, does not consider gestational age, sex, or country/region-specific differences in mean birth weight and maternal body weight. This issue is particularly relevant for Asia, where 60% of the world's population lives, due to variations in maternal size and birth weights across populations. Large for gestational age (LGA), defined as birth weight > 90th centile, is a more sensitive measure as it considers gestational age and sex, though it is dependent on the choice of growth charts. We aimed to review reporting of macrosomia and LGA in Asia. We reviewed the literature on prevalence and risk of macrosomia and LGA in Asia over the last 29 years. Prevalence of macrosomia ranged from 0.5% (India) to 13.9% (China) while prevalence of LGA ranged from 4.3% (Korea) to 22.1% (China), indicating substantial variation in prevalence within and between Asian countries. High pre-pregnancy body mass index, excessive gestational weight gain, and impaired glucose tolerance conferred risk of macrosomia/LGA. Incidence of macrosomia and LGA varies substantially within and between Asian countries, as do the growth charts and definitions. The latter makes it impossible to make comparisons but suggests differences in intrauterine growth between populations. Reporting LGA, using standardized country/regional growth charts, would better capture the incidence of high birth weight and allow for comparison and identification of contributing factors. Better understanding of local drivers of excessive intrauterine growth could enable development of improved strategies for prevention and management of LGA

    Association of genetic variation in FTO with risk of obesity and type 2 diabetes with data from 96,551 East and South Asians

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    Aims/hypothesis: FTOFTO harbours the strongest known obesity-susceptibility locus in Europeans. While there is growing evidence for a role for FTOFTO in obesity risk in Asians, its association with type 2 diabetes, independently of BMI, remains inconsistent. To test whether there is an association of the FTOFTO locus with obesity and type 2 diabetes, we conducted a meta-analysis of 32 populations including 96,551 East and South Asians. Methods: All studies published on the association between FTOFTO-rs9939609 (or proxy [r2^2 > 0.98]) and BMI, obesity or type 2 diabetes in East or South Asians were invited. Each study group analysed their data according to a standardised analysis plan. Association with type 2 diabetes was also adjusted for BMI. Random-effects meta-analyses were performed to pool all effect sizes. Results: The FTOFTO-rs9939609 minor allele increased risk of obesity by 1.25-fold/allele (p = 9.0 × 1019^{−19}), overweight by 1.13-fold/allele (p = 1.0 × 1011^{−11}) and type 2 diabetes by 1.15-fold/allele (p = 5.5 × 108^{−8}). The association with type 2 diabetes was attenuated after adjustment for BMI (OR 1.10-fold/allele, p = 6.6 × 105^{−5}). The FTOFTO-rs9939609 minor allele increased BMI by 0.26 kg/m2 per allele (p = 2.8 × 1017^{−17}), WHR by 0.003/allele (p = 1.2 × 106^{−6}), and body fat percentage by 0.31%/allele (p = 0.0005). Associations were similar using dominant models. While the minor allele is less common in East Asians (12–20%) than South Asians (30–33%), the effect of FTOFTO variation on obesity-related traits and type 2 diabetes was similar in the two populations. Conclusions/interpretation: FTOFTO is associated with increased risk of obesity and type 2 diabetes, with effect sizes similar in East and South Asians and similar to those observed in Europeans. Furthermore, FTOFTO is also associated with type 2 diabetes independently of BMI. Electronic supplementary material The online version of this article (doi:10.1007/s00125-011-2370-7) contains peer-reviewed but unedited supplementary material, which is available to authorised users

    Publisher Correction: Sex-dimorphic genetic effects and novel loci for fasting glucose and insulin variability.

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    Correction to: Nature Communications https://doi.org/10.1038/s41467-020-19366-9, published online 5 January 2021. The original version of this Article contained an error in Fig. 2, in which panels a and b were inadvertently swapped. This has now been corrected in the PDF and HTML versions of the Article

    Publisher Correction: Sex-dimorphic genetic effects and novel loci for fasting glucose and insulin variability

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    Publisher Correction: Sex-dimorphic genetic effects and novel loci for fasting glucose and insulin variability.

    Get PDF
    Correction to: Nature Communications https://doi.org/10.1038/s41467-020-19366-9, published online 5 January 2021. The original version of this Article contained an error in Fig. 2, in which panels a and b were inadvertently swapped. This has now been corrected in the PDF and HTML versions of the Article

    Shedding Light on the Galaxy Luminosity Function

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    From as early as the 1930s, astronomers have tried to quantify the statistical nature of the evolution and large-scale structure of galaxies by studying their luminosity distribution as a function of redshift - known as the galaxy luminosity function (LF). Accurately constructing the LF remains a popular and yet tricky pursuit in modern observational cosmology where the presence of observational selection effects due to e.g. detection thresholds in apparent magnitude, colour, surface brightness or some combination thereof can render any given galaxy survey incomplete and thus introduce bias into the LF. Over the last seventy years there have been numerous sophisticated statistical approaches devised to tackle these issues; all have advantages -- but not one is perfect. This review takes a broad historical look at the key statistical tools that have been developed over this period, discussing their relative merits and highlighting any significant extensions and modifications. In addition, the more generalised methods that have emerged within the last few years are examined. These methods propose a more rigorous statistical framework within which to determine the LF compared to some of the more traditional methods. I also look at how photometric redshift estimations are being incorporated into the LF methodology as well as considering the construction of bivariate LFs. Finally, I review the ongoing development of completeness estimators which test some of the fundamental assumptions going into LF estimators and can be powerful probes of any residual systematic effects inherent magnitude-redshift data.Comment: 95 pages, 23 figures, 3 tables. Now published in The Astronomy & Astrophysics Review. This version: bring in line with A&AR format requirements, also minor typo corrections made, additional citations and higher rez images adde
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