6,614 research outputs found
Household food insecurity status and Hispanic immigrant childrenâs body mass index and adiposity
Objectives: Despite the high prevalence rates of food insecurity and obesity among children of Hispanic immigrants, there has been a dearth of research on the direct relationship between food insecurity and obesity among this population. Further, prior research examining the association between food insecurity and body composition among children of Hispanic immigrants have not considered adiposity, specifically percent body fat (%BF) and waist circumference (WC), as outcome measurements. The following study contributes to the literature by examining the association between food insecurity and two adiposity measurements, %BF and WC, along with body mass index (BMI) among a sample of young Hispanic immigrant children.
Methods: Cross-sectional survey and direct body composition assessments were collected among 49 low-income Hispanic immigrant children (mean age = 5.5. years) and their 44 mothers (mean age = 35.5 years) from two Houston-area community centers. Data were collected on household food security status using the 18-item USDA scale, demographic characteristics, and measured height, weight, body fat percentage, and waist circumference from children and mothers.
Results: Sixty-five percent of children resided in a food insecure household, 31% of the children were obese in terms of %BF, and 24% were obese in terms of BMI. A greater percentage of food secure children were classified as obese in terms of %BF, BMI, and had an elevated waist circumference. A direct relationship was not observed between food insecurity and elevated waist circumference (OR = .08, p = .10); however, children living in food insecure households had 89% lower odds of having an elevated %BF (OR = 0.11, p \u3c .01), 93% lower odds of being obese (OR = 0.07, p \u3c .05), and 87% lower odds of being overweight/obese (OR = 0.13, p \u3c .05).
Conclusions: In young children of Hispanic immigrants, food insecurity was related to healthier levels of %BF and BMI. Studies that track adiposity and weight status of children of Hispanic immigrants in relation to food insecurity over time are needed to further understand why food insecurity and obesity co-exist for some groups but not others
Characterization of Structures of Equivalent Tissue With a Pixel Detector
Research using hybrid pixel detectors in medical physics is on the rise. Timepix detectors have arrays of 256 Ă 256 pixels with a resolution of 55 ÎŒm. Here, and by using Timepix counts instead of Hounsfield units, we present a calibration curve of a Timepix detector analog to those used for CT calibration. Experimentation consisted of the characterization of electron density in 10 different kinds of tissue equivalent samples from a CIRS 062M phantom (lung, 3 kinds of bones, fat, breast, muscle, water and air). Radiation of the detector was performed using an orthodontic X-ray machine at 70 KeV and .06 second of tube current with a purpose-built aluminum collimator. Data acquisition was performed at 1 frame per second and taking 3 frames per phantom. We were able to find a curve whose behavior was similar to others already published. This will lead to the verification of the usage of Timepix for identification of different tissues in an organ
Effectiveness of community-based integrated care in frail COPD patients: a randomised controlled trial
Background:
Chronic obstructive pulmonary disease (COPD) generates a high burden on health care, and hospital admissions represent a substantial proportion of the overall costs of the disease. Integrated care (IC) has shown efficacy to reduce hospitalisations in COPD patients at a pilot level. Deployment strategies for IC services require assessment of effectiveness at the health care system level. Aims:
The aim of this study was to explore the effectiveness of a community-based IC service in preventing hospitalisations and emergency department (ED) visits in stable frail COPD patients. Methods:
From April to December 2005, 155 frail community-dwelling COPD patients were randomly allocated either to IC (n=76, age 73 (8) years, forced expiratory volume during the first second, FEV1 41(19) % predicted) or usual care (n=84, age 75(9) years, FEV1 44 (20) % predicted) and followed up for 12 months. The IC intervention consisted of the following: (a) patientâs empowerment for self-management; (b) an individualised care plan; (c) access to a call centre; and (d) coordination between the levels of care. Thereafter, hospital admissions, ED visits and mortality were monitored for 6 years. Results:
IC enhanced self-management (P=0.02), reduced anxietyâdepression (P=0.001) and improved health-related quality of life (P=0.02). IC reduced both ED visits (P=0.02) and mortality (P=0.03) but not hospital admission. No differences between the two groups were seen after 6 years. Conclusion:
The intervention improved clinical outcomes including survival and decreased the ED visits, but it did not reduce hospital admissions. The study facilitated the identification of two key requirements for adoption of IC services in the community: appropriate risk stratification of patients, and preparation of the community-based work force
A Study of the Near-Ultraviolet Spectrum of Vega
UV, optical, and near-IR spectra of Vega have been combined to test our
understanding of stellar atmospheric opacities, and to examine the possibility
of constraining chemical abundances from low-resolution UV fluxes. We have
carried out a detailed analysis assuming Local Thermodynamic Equilibrium (LTE)
to identify the most important contributors to the UV continuous opacity: H,
H, C I, and Si II. Our analysis also assumes that Vega is spherically
symmetric and its atmosphere is well described with the plane parallel
approximation. Comparing observations and computed fluxes we have been able to
discriminate between two different flux scales that have been proposed, the
IUE-INES and the HST scales, favoring the latter. The effective temperature and
angular diameter derived from the analysis of observed optical and near-UV
spectra are in very good agreement with previous determinations based on
different techniques. The silicon abundance is poorly constrained by the UV
observations of the continuum and strong lines, but the situation is more
favorable for carbon and the abundances inferred from the UV continuum and
optical absorption lines are in good agreement. Some spectral intervals in the
UV spectrum of Vega that the calculations do not reproduce well are likely
affected by deviations from LTE, but we conclude that our understanding of UV
atmospheric opacities is fairly complete for early A-type stars.Comment: 13 pages, 9 figures, to be published in Ap
A system of three transiting super-Earths in a cool dwarf star
We present the detection of three super-Earths transiting the cool star
LP415-17, monitored by K2 mission in its 13th campaign. High resolution spectra
obtained with HARPS-N/TNG showed that the star is a mid-late K dwarf. Using
spectral synthesis models we infer its effective temperature, surface gravity
and metallicity and subse- quently determined from evolutionary models a
stellar radius of 0.58 R Sun. The planets have radii of 1.8, 2.6 and 1.9 R
Earth and orbital periods of 6.34, 13.85 and 40.72 days. High resolution images
discard any significant contamination by an intervening star in the line of
sight. The orbit of the furthest planet has radius of 0.18 AU, close to the
inner edge of the habitable zone. The system is suitable to improve our
understanding of formation and dynamical evolution of super-Earth systems in
the rocky - gaseous threshold, their atmospheres, internal structure,
composition and interactions with host stars.Comment: Accepted for publication in MNRAS Letter
Classical Cepheids: Yet another version of the Baade-Becker-Wesselink method
We propose a new version of the Baade--Becker--Wesselink technique, which
allows one to independently determine the colour excess and the intrinsic
colour of a radially pulsating star, in addition to its radius, luminosity, and
distance. It is considered to be a generalization of the Balona approach. The
method also allows the function F(CI) = BC + 10 log (Teff) for the class of
pulsating stars considered to be calibrated. We apply this technique to a
number of classical Cepheids with very accurate light and radial-velocity
curves and with bona fide membership in open clusters (SZ Tau, CF Cas, U Sgr,
DL Cas, GY Sge), and find the results to agree well with the reddening
estimates of the host open clusters. The new technique can also be applied to
other pulsating variables, e.g. RR Lyrae and RV Tauri.Comment: 6 pages, 2 figures, 1 table; Submitted to Astrophysical Bulletin,
201
Synthesis of titanate nanostructures using amorphous precursor material and their adsorption/photocatalytic properties
This paper reports on a new and swift hydrothermal chemical route to prepare
titanate nanostructures (TNS) avoiding the use of crystalline TiO2 as starting
material. The synthesis approach uses a commercial solution of TiCl3 as
titanium source to prepare an amorphous precursor, circumventing the use of
hazardous chemical compounds. The influence of the reaction temperature and
dwell autoclave time on the structure and morphology of the synthesised
materials was studied. Homogeneous titanate nanotubes with a high
length/diameter aspect ratio were synthesised at 160^{\circ}C and 24 h. A band
gap of 3.06\pm0.03 eV was determined for the TNS samples prepared in these
experimental conditions. This value is red shifted by 0.14 eV compared to the
band gap value usually reported for the TiO2 anatase. Moreover, such samples
show better adsorption capacity and photocatalytic performance on the dye
rhodamine 6G (R6G) photodegradation process than TiO2 nanoparticles. A 98%
reduction of the R6G concentration was achieved after 45 minutes of irradiation
of a 10 ppm dye aqueous solution and 1 g/L of TNS catalyst.Comment: 29 pages, 10 figures, accepted for publication in Journal of
Materials Scienc
The Standard Model from a New Phase Transition on the Lattice
Several years ago it was conjectured in the so-called Roma Approach, that
gauge fixing is an essential ingredient in the lattice formulation of chiral
gauge theories. In this paper we discuss in detail how the gauge-fixing
approach may be realized. As in the usual (gauge invariant) lattice
formulation, the continuum limit corresponds to a gaussian fixed point, that
now controls both the transversal and the longitudinal modes of the gauge
field. A key role is played by a new phase transition separating a conventional
Higgs or Higgs-confinement phase, from a phase with broken rotational
invariance. In the continuum limit we expect to find a scaling region, where
the lattice correlators reproduce the euclidean correlation functions of the
target (chiral) gauge theory, in the corresponding continuum gauge.Comment: 16 pages, revtex, one figure. Clarifications made, mainly in sections
3 and 6 that deal with the fermion action, to appear in Phys Rev
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