5 research outputs found

    Relationship Between Parent Demographic Characteristics, Perinatal and Early Childhood Behaviors, and Body Mass Index Among Preschool-Age Children

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    Approximately 25% of US 2-to-5-year olds are overweight and ethnic minority groups are disproportionately affected. We explored the relationship between parent demographic characteristics, various perinatal/early childhood (EC) factors, and child body mass index (BMI) to determine possible contributors to these disparities. A preschool-based randomized controlled (N = 28 centers) obesity prevention intervention was conducted among multiethnic 2-to-5 year olds. Baseline assessment of demographic characteristics, various perinatal/EC factors, and child BMI were analyzed via generalized linear mixed models and logistic regression analysis. Foreign-born parents were almost 2.5 times as likely to have an obese child versus children of US-born parents (OR 2.43, 95% CI 1.53-3.87). Families who spoke Spanish only or a combination of Creole/English at home were over twice as likely to have an obese preschool child versus families who spoke English only at home. Parent place of birth and language spoken at home plays a significant role in early childhood obesity. Future early childhood healthy weight initiatives should incorporate strategies that take into account these particular parent characteristics

    Insights into the high-energy gamma-ray emission of markarian 501 from extensive multifrequency observations in the fermi era

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    We report on the gamma-ray activity of the blazar Mrk 501 during the first 480 days of Fermi operation. We find that the average Large Area Telescope (LAT) gamma-ray spectrum of Mrk 501 can be well described by a single power-law function with a photon index of 1.78 +/- 0.03. While we observe relatively mild flux variations with the Fermi-LAT (within less than a factor of two), we detect remarkable spectral variability where the hardest observed spectral index within the LAT energy range is 1.52 +/- 0.14, and the softest one is 2.51 +/- 0.20. These unexpected spectral changes do not correlate with the measured flux variations above 0.3 GeV. In this paper, we also present the first results from the 4.5 month long multifrequency campaign (2009 March 15-August 1) on Mrk 501, which included the Very Long Baseline Array (VLBA), Swift, RXTE, MAGIC, and VERITAS, the F-GAMMA, GASP-WEBT, and other collaborations and instruments which provided excellent temporal and energy coverage of the source throughout the entire campaign. The extensive radio to TeV data set from this campaign provides us with the most detailed spectral energy distribution yet collected for this source during its relatively low activity. The average spectral energy distribution of Mrk 501 is well described by the standard one-zone synchrotron self-Compton (SSC) model. In the framework of this model, we find that the dominant emission region is characterized by a size less than or similar to 0.1 pc (comparable within a factor of few to the size of the partially resolved VLBA core at 15-43 GHz), and that the total jet power (similar or equal to 10(44) erg s(-1)) constitutes only a small fraction (similar to 10(-3)) of the Eddington luminosity. The energy distribution of the freshly accelerated radiating electrons required to fit the time-averaged data has a broken power-law form in the energy range 0.3 GeV-10 TeV, with spectral indices 2.2 and 2.7 below and above the break energy of 20 GeV. We argue that such a form is consistent with a scenario in which the bulk of the energy dissipation within the dominant emission zone of Mrk 501 is due to relativistic, proton-mediated shocks. We find that the ultrarelativistic electrons and mildly relativistic protons within the blazar zone, if comparable in number, are in approximate energy equipartition, with their energy dominating the jet magnetic field energy by about two orders of magnitude
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