488 research outputs found
Weight Loss Associated With Different Patterns of Self-Monitoring Using the Mobile Phone App My Meal Mate
Background: Obesity is a major global public health issue due to its association with a number of serious chronic illnesses and its high economic burden to health care providers. Self-monitoring of diet has been consistently linked to weight loss. However, there is limited evidence about how frequently individuals need to monitor their diet for optimal weight loss. Objective: The aim of this paper is to describe app usage frequency and pattern in the mobile phone arm of a previously conducted randomized controlled trial. The relationship between frequency and pattern of electronic dietary self-monitoring and weight loss is also investigated. Methods: A randomized pilot trial comparing three methods of self-monitoring (mobile phone app, paper diary, Web-based) was previously conducted. Trial duration was 6 months. The mobile phone app My Meal Mate features an electronic food diary and encourages users to self-monitor their dietary intake. All food consumption data were automatically uploaded with a time and date stamp. Post hoc regression analysis of app usage patterns was undertaken in the My Meal Mate group (n=43; female: 77%, 33/43; white: 100%, 43/43; age: mean 41, SD 9 years; body mass index: mean 34, SD 4 kg/m2) to explore the relationship between frequency and pattern of electronic dietary self-monitoring and weight loss. Baseline characteristics of participants were also investigated to identify any potential predictors of dietary self-monitoring. Results: Regression analysis showed that those in the highest frequency-of-use category (recorded â„129 days on the mobile phone app) had a â6.4 kg (95% CI â10.0 to â2.9) lower follow-up weight (adjusted for baseline weight) than those in the lowest frequency-of-use category (recorded â€42 days; P<.001). Long-term intermittent monitoring over 6 months appeared to facilitate greater mean weight loss than other patterns of electronic self-monitoring (ie, monitoring over the short or moderate term and stopping and consistently monitoring over consecutive days). Participant characteristics such as age, baseline weight, sex, ethnicity, conscientiousness, and consideration of future consequences were not statistically associated with extent of self-monitoring. Conclusions: The results of this post hoc exploratory analysis indicate that duration and frequency of app use is associated with improved weight loss, but further research is required to identify whether there are participant characteristics that would reliably predict those who are most likely to regularly self-monitor their diet
Regular spherical dust spacetimes
Physical (and weak) regularity conditions are used to determine and classify
all the possible types of spherically symmetric dust spacetimes in general
relativity. This work unifies and completes various earlier results. The
junction conditions are described for general non-comoving (and non-null)
surfaces, and the limits of kinematical quantities are given on all comoving
surfaces where there is Darmois matching. We show that an inhomogeneous
generalisation of the Kantowski-Sachs metric may be joined to the
Lemaitre-Tolman-Bondi metric. All the possible spacetimes are explicitly
divided into four groups according to topology, including a group in which the
spatial sections have the topology of a 3-torus. The recollapse conjecture (for
these spacetimes) follows naturally in this approach.Comment: Minor improvements, additional references. Accepted by GR
Prevalence of Hepatitis B surface antigen (HBsAg) among visitors of Shashemene General Hospital voluntary counseling and testing center
<p>Abstract</p> <p>Background</p> <p>Hepatitis B virus (HBV) infection is significant health problem, as it can lead to chronic hepatitis, liver cirrhosis, and hepatic carcinoma. Due to shared routes of transmission, HBV and human immunodeficiency virus (HIV) co-infection is common and is an emerging concern in the clinical management of patients because of increased mortality, accelerated hepatic disease progression, and the frequent hepatotoxicity caused by anti-retroviral therapy. The aim of this study was to determine the prevalence of Hepatitis B surface antigen (HBsAg) and its risk factors, among individuals visiting Shashemene General Hospital VCT center.</p> <p>Findings</p> <p>Institution based cross-sectional study was performed from November 3, 2008 to December 29, 2008 and 384 voluntary counseling and testing (VCT) clients were investigated. Data on socio demographic and HBV risk factors was collected using structured questionnaires. Blood samples were collected and screened for hepatitis B surface antigen (HBsAg) and HIV by commercially available rapid test kits. The prevalence of HBsAg in this study group was 5.7%. Fourteen percent of HIV positive subjects (8/57) and 4.3% (14/327) of HIV negative subjects were positive for HBsAg. Significantly high prevalence of HBsAg was observed among individuals who had history of invasive procedures, like tooth extraction, abortion and ear piercing; history of hospital admission, history of unsafe inject and HIV positives.</p> <p>Conclusions</p> <p>Although HBsAg prevalence is much higher among subjects who are HIV positive (14.0% versus 4.3%), the prevalence of HBsAg in HIV negative subjects is high enough to warrant a recommendation to screen all clients at VCT centers irrespective of HIV status.</p
Effects of ambient air pollution on functional status in patients with chronic congestive heart failure: a repeated-measures study
<p>Abstract</p> <p>Background</p> <p>Studies using administrative data report a positive association between ambient air pollution and the risk of hospitalization for congestive heart failure (HF). Circulating levels of B-type natriuretic peptide (BNP) are directly associated with cardiac hemodynamics and symptom severity in patients with HF and, therefore, serves as a marker of functional status. We tested the hypothesis that BNP levels would be positively associated with short-term changes in ambient pollution levels among 28 patients with chronic stable HF and impaired systolic function.</p> <p>Methods</p> <p>BNP was measured in whole blood at 0, 6, and 12 weeks. We used linear mixed models to evaluate the association between fine particulate matter (PM<sub>2.5</sub>), carbon monoxide, sulfur dioxide, nitrogen dioxide, ozone, and black carbon and log(BNP). Lags of 0 to 3 days were considered in separate models. We calculated the intraclass correlation coefficient and within-subject coefficient of variation as measures of reproducibility.</p> <p>Results</p> <p>We found no association between any pollutant and measures of BNP at any lag. For example, a 10 ÎŒg/m<sup>3 </sup>increase in PM<sub>2.5 </sub>was associated with a 0.8% (95% CI: -16.4, 21.5; p = 0.94) increase in BNP on the same day. The within-subject coefficient of variation was 45% on the natural scale and 9% on the log scale.</p> <p>Conclusion</p> <p>These results suggest that serial BNP measurements are unlikely to be useful in a longitudinal study of air pollution-related acute health effects. The magnitude of expected ambient air pollution health effects appears small in relation to the considerable within-person variability in BNP levels in this population.</p
The Einstein-Vlasov sytem/Kinetic theory
The main purpose of this article is to guide the reader to theorems on global
properties of solutions to the Einstein-Vlasov system. This system couples
Einstein's equations to a kinetic matter model. Kinetic theory has been an
important field of research during several decades where the main focus has
been on nonrelativistic- and special relativistic physics, e.g. to model the
dynamics of neutral gases, plasmas and Newtonian self-gravitating systems. In
1990 Rendall and Rein initiated a mathematical study of the Einstein-Vlasov
system. Since then many theorems on global properties of solutions to this
system have been established. The Vlasov equation describes matter
phenomenologically and it should be stressed that most of the theorems
presented in this article are not presently known for other such matter models
(e.g. fluid models). The first part of this paper gives an introduction to
kinetic theory in non-curved spacetimes and then the Einstein-Vlasov system is
introduced. We believe that a good understanding of kinetic theory in
non-curved spacetimes is fundamental in order to get a good comprehension of
kinetic theory in general relativity.Comment: 31 pages. This article has been submitted to Living Rev. Relativity
(http://www.livingreviews.org
Study of ZÎł events and limits on anomalous ZZÎł and Zγγ couplings in ppÌ collisions at s=1.96TeV
We present a measurement of the ZÎł production cross section and limits on anomalous ZZÎł and Zγγ couplings for form-factor scales of Î=750 and 1000 GeV. The measurement is based on 138 (152) candidates in the eeÎł (ÎŒÎŒÎł) final state using 320(290)pb-1 of ppÌ collisions at s=1.96TeV. The 95% C.L. limits on real and imaginary parts of individual anomalous couplings are |h10,30Z|<0.23, |h20,40Z|<0.020, |h10,30Îł|<0.23, and |h20,40Îł|<0.019 for Î=1000GeV. © 2005 The American Physical Society
Reaction rates and transport in neutron stars
Understanding signals from neutron stars requires knowledge about the
transport inside the star. We review the transport properties and the
underlying reaction rates of dense hadronic and quark matter in the crust and
the core of neutron stars and point out open problems and future directions.Comment: 74 pages; commissioned for the book "Physics and Astrophysics of
Neutron Stars", NewCompStar COST Action MP1304; version 3: minor changes,
references updated, overview graphic added in the introduction, improvements
in Sec IV.A.
Search for gamma-ray emission from magnetars with the Fermi Large Area Telescope
We report on the search for 0.1-10 GeV emission from magnetars in 17 months
of Fermi Large Area Telescope (LAT) observations. No significant evidence for
gamma-ray emission from any of the currently-known magnetars is found. The most
stringent upper limits to date on their persistent emission in the Fermi-LAT
energy range are estimated between ~10^{-12}-10^{-10} erg/s/cm2, depending on
the source. We also searched for gamma-ray pulsations and possible outbursts,
also with no significant detection. The upper limits derived support the
presence of a cut-off at an energy below a few MeV in the persistent emission
of magnetars. They also show the likely need for a revision of current models
of outer gap emission from strongly magnetized pulsars, which, in some
realizations, predict detectable GeV emission from magnetars at flux levels
exceeding the upper limits identified here using the Fermi-LAT observations.Comment: ApJ Letters in press; Corresponding authors: Caliandro G. A., Hadasch
D., Rea N., Burnett
Estimation of Short-Term Effects of Air Pollution on Stroke Hospital Admissions in Wuhan, China
Background and Objective:High concentrations of air pollutants have been linked to increased incidence of stroke in North America and Europe but not yet assessed in mainland China. The aim of this study is to evaluate the association between stroke hospitalization and short-term elevation of air pollutants in Wuhan, China.Methods:Daily mean NO2, SO2 and PM10 levels, temperature and humidity were obtained from 2006 through 2008. Data on stroke hospitalizations (ICD 10: I60-I69) at four hospitals in Wuhan were obtained for the same period. A time-stratified case-crossover design was performed by season (April-September and October-March) to assess effects of pollutants on stroke hospital admissions.Results:Pollution levels were higher in October-March with averages of 136.1 Όg/m3 for PM10, 63.6 Όg/m3 for NO2 and 71.0 Όg/m3 for SO2 than in April-September when averages were 102.0 Όg/m3, 41.7 Όg/m3 and 41.7 Όg/m3, respectively (p<.001). During the cold season, every 10 Όg/m3 increase in NO2 was associated with a 2.9% (95%C.I. 1.2%-4.6%) increase in stroke admissions on the same day. Every 10 ug/m3 increase in PM10 daily concentration was significantly associated with an approximate 1% (95% C.I. 0.1%-1.4%) increase in stroke hospitalization. A two-pollutant model indicated that NO2 was associated with stroke admissions when controlling for PM10. During the warm season, no significant associations were noted for any of the pollutants.Conclusions:Exposure to NO2 is significantly associated with stroke hospitalizations during the cold season in Wuhan, China when pollution levels are 50% greater than in the warm season. Larger and multi-center studies in Chinese cities are warranted to validate our findings. © 2013 Xiang et al
Detection of Gamma-Ray Emission from the Starburst Galaxies M82 and NGC 253 with the Large Area Telescope on Fermi
We report the detection of high-energy gamma-ray emission from two starburst
galaxies using data obtained with the Large Area Telescope on board the Fermi
Gamma-ray Space Telescope. Steady point-like emission above 200 MeV has been
detected at significance levels of 6.8 sigma and 4.8 sigma respectively, from
sources positionally coincident with locations of the starburst galaxies M82
and NGC 253. The total fluxes of the sources are consistent with gamma-ray
emission originating from the interaction of cosmic rays with local
interstellar gas and radiation fields and constitute evidence for a link
between massive star formation and gamma-ray emission in star-forming galaxies.Comment: Submitted to ApJ Letter
- âŠ