5,984 research outputs found
Nonequilibrium fluctuations in a resistor
In small systems where relevant energies are comparable to thermal agitation,
fluctuations are of the order of average values. In systems in thermodynamical
equilibrium, the variance of these fluctuations can be related to the
dissipation constant in the system, exploiting the Fluctuation-Dissipation
Theorem (FDT). In non-equilibrium steady systems, Fluctuations Theorems (FT)
additionally describe symmetry properties of the probability density functions
(PDFs) of the fluctuations of injected and dissipated energies. We
experimentally probe a model system: an electrical dipole driven out of
equilibrium by a small constant current , and show that FT are
experimentally accessible and valid. Furthermore, we stress that FT can be used
to measure the dissipated power in the system by just
studying the PDFs symmetries.Comment: Juillet 200
The impact of maternal BMI, gestational weight gain, and breastfeeding on early childhood weight: Analysis of a statewide WIC dataset
Early childhood obesity is a persistent health concern with more frequent and significant impact on low-income families. Maternal weight factors impact offspring weight status, but evidence on whether breastfeeding protects against this impact is mixed. This analysis examined a model to predict early childhood obesity risk, simultaneously accounting for maternal pre-pregnancy body mass index (BMI), gestational weight gain, and breastfeeding. The team analyzed 27,016 unique maternal-child dyadic records collected via the Supplemental Nutrition Program for Wisconsin Women, Infants, and Children (WIC) between 2009 and 2011. Generalized Linear Modeling, specifically logistic regression, was used to predict a child\u27s risk of obesity given the mother\u27s pre-pregnancy BMI, gestational weight gain, and duration of breastfeeding. For each 1 kg/m2 increase in pre-pregnancy BMI, there was a 4.5% increase in risk of obesity compared to children with mothers of normal BMI. Children whose mothers had excessive gestational weight gain were 50% more likely to have obesity compared to those whose mothers had ideal weight gain. For each week of additional breastfeeding, there was a 1.9% increased risk of obesity. The risk models did not differ by race. In this model, accounting for pre-pregnancy weight, gestational weight gain, and breastfeeding among a diverse, low-income sample, women with pre-pregnancy overweight and obesity or who had excessive gestational weight gain had the highest risk of early childhood obesity. While breastfeeding is healthy for many reasons, providers should focus on maternal weight-related behaviors when counseling mothers about how to avoid risk of early childhood obesity
Mediating Effects of Positive Thinking and Social Support on Suicide Resilience
Suicide has been the second leading cause of death for 18- to 24-year-olds in the United States since 2011. The stress experienced by undergraduate college students has the potential to increase one’s risk for suicide. Resilience theory was used as a theoretical framework to examine the interplay between risk and protective factors. A cross-sectional and correlational design was used to assess the mediating effects of positive thinking and/or social support on suicide resilience in 131 college students 18 to 24 years old who completed an online survey. The study found an indirect effect of self-esteem on suicide resilience through positive thinking and social support indicating that as self-esteem increases, positive thinking and social support also increase, which leads to an increase in resilience. The study also found a direct effect of self-esteem, positive thinking, and social support on suicide resilience. The findings inform the development of tailored interventions to build suicide resilience in college students
We the swarm: Methodological, theoretical, and societal (r)evolutions in collective decision-making research
A two-way interactive broadband satellite architecture to break the digital divide barrier
September 24-26, 2007, Turin, Ital
Dynamical localization of matter wave solitons in managed barrier potentials
The bright matter wave soliton propagation through a barrier with a rapidly
oscillating position is investigated. The averaged over rapid oscillations
Gross-Pitaevskii (GP) equation is derived. It is shown that the soliton is
dynamically trapped by the effective double-barrier.
The analytical predictions for the soliton effective dynamics is confirmed by
the numerical simulations of the full GP equation.Comment: 10 pages, 6 figure
TV-Centric technologies to provide remote areas with two-way satellite broadband access
October 1-2, 2007, Rome, Italy TV-Centric Technologies To Provide Remote Areas With Two-Way Satellite Broadband Acces
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