2,890 research outputs found
Brief Report: Factors Associated with Asthma Management Self-Efficacy Among 7th and 8th Grade Students
Objective Examine correlates of asthma self-management among 12,154 adolescents with physician-diagnosed asthma. Methods All 7th and 8th grade students in North Carolina completed a survey to assess asthma prevalence and self-management behaviors among those with asthma. Results Adolescents who were allowed to carry their inhaled medication at school, shown how to use a peak flow meter, and had access to more asthma care resources were more confident that they could prevent an asthma exacerbation. Adolescents who were allowed to carry their inhaled medication at school and who had a private doctor were more confident that they could control their symptoms. Adolescents taking anti-inflammatory medicine were less confident that they could prevent an exacerbation and control their symptoms. Conclusions Various indicators of autonomy and control were associated with greater self-efficacy for managing asthma. Adolescents who require anti-inflammatory medicines would benefit from additional intervention efforts to improve their asthma management self-efficacy
Peripheral heavy ion collisions as a probe of the nuclear gluon distribution
At high energies a quark-gluon plasma is expected to be formed in heavy ion
collisions at RHIC and LHC. The theoretical description of these processes is
directly associated to a complete knowledge of the details of medium effects in
the nuclear gluon distribution. In this paper we analyze the possibility to
constraint the behavior of this distribution considering peripheral heavy ion
collisions. We reanalyze the photoproduction of heavy quarks for the deduction
of the in-medium gluon distribution using three current parameterizations for
this parton distribution. Moreover, we show that the elastic photoproduction of
vector mesons is a potential process to probe the nuclear gluon distribution.Comment: 8 figures, accepted for publication in Physicsl review
The initial gluon multiplicity in heavy ion collisions
The initial gluon multiplicity per unit area per unit rapidity, dN/L^2/d\eta,
in high energy nuclear collisions, is equal to f_N (g^2\mu L) (g^2\mu)^2/g^2,
with \mu^2 proportional to the gluon density per unit area of the colliding
nuclei. For an SU(2) gauge theory, we compute f_N (g^2\mu L)=0.14\pm 0.01 for a
wide range in g^2\mu L. Extrapolating to SU(3), we predict dN/L^2/d\eta for
values of g^2\mu L in the range relevant to the Relativistic Heavy Ion Collider
and the Large Hadron Collider. We compute the initial gluon transverse momentum
distribution, dN/L^2/d^2 k_\perp, and show it to be well behaved at low
k_\perp.Comment: LaTex 10 pgs., 3 figure
Microfluidics Generation of Millimeter-sized Matrigel Droplets
Significant progress has been made to increase access to droplet
microfluidics for labs with limited microfluidics expertise or fabrication
equipment. In particular, using off-the-shelf systems has been a valuable
approach. However, the ability to modify a channel design and, thus, the
functional characteristics of the system is of great value. In this work, we
describe the development of co-flow microfluidics and their fabrication methods
for generating uniform millimeter-sized (0.5 - 2 mm) hydrogel droplets. Two
complementary approaches based on desktop CO2 laser cutting were developed to
prototype and build durable co-flow droplet microfluidics. After demonstrating
the co-flow systems, water-in-oil experiments and dimensionless number analysis
were used to examine the operational characteristics of the system.
Specifically, the Capillary number analysis indicated that millimeter-sized
droplet generators operated in the desirable geometry-controlled regime despite
their length scales being larger than traditional microfluidics systems. Next,
the tunable generation of Matrigel droplets was demonstrated. By adjusting the
relative flow rates, the droplet size could be tuned. Finally, we demonstrated
fibroblast encapsulation and cell viability for up to 7 days as a
proof-of-concept experiment. The systems presented are simple and effective
tools to generate robust hydrogel droplets and increase the accessibility of
this technology to teaching labs or research settings with limited resources or
access to microfluidics.Comment: 14 pages, 5 figures, 1 tabl
Provider Demonstration and Assessment of Child Device Technique During Pediatric Asthma Visits
The purposes of this study were to (a) describe the extent to which children use metered dose inhalers, turbuhalers, diskuses, and peak flow meters correctly, and (b) investigate how often providers assess and demonstrate use of metered dose inhalers, turbuinhalers, diskuses, and peak flow meters during pediatric asthma visits
AD Leonis: Radial Velocity Signal of Stellar Rotation or SpinâOrbit Resonance?
AD Leonis is a nearby magnetically active M dwarf. We find Doppler variability with a period of 2.23 days, as well as photometric signals: (1) a short-period signal, which is similar to the radial velocity signal, albeit with considerable variability; and (2) a long-term activity cycle of 4070 ± 120 days. We examine the short-term photometric signal in the available All-Sky Automated Survey and Microvariability and Oscillations of STars (MOST) photometry and find that the signal is not consistently present and varies considerably as a function of time. This signal undergoes a phase change of roughly 0.8 rad when considering the first and second halves of the MOST data set, which are separated in median time by 3.38 days. In contrast, the Doppler signal is stable in the combined High-Accuracy Radial velocity Planet Searcher and High Resolution Echelle Spectrometer radial velocities for over 4700 days and does not appear to vary in time in amplitude, phase, period, or as a function of extracted wavelength. We consider a variety of starspot scenarios and find it challenging to simultaneously explain the rapidly varying photometric signal and the stable radial velocity signal as being caused by starspots corotating on the stellar surface. This suggests that the origin of the Doppler periodicity might be the gravitational tug of a planet orbiting the star in spinâorbit resonance. For such a scenario and no spinâorbit misalignment, the measured v sin i indicates an inclination angle of 15Â°ÌŁ5 ± 2Â°ÌŁ5 and a planetary companion mass of 0.237 ± 0.047 M Jup
Communication During Pediatric Asthma Visits and Self-Reported Asthma Medication Adherence
Our objectives were to examine how certain aspects of provider-patient communication recommended by national asthma guidelines (ie, provider asking for child and caregiver input into the asthma treatment plan) were associated with child asthma medication adherence 1 month after an audio-taped medical visit
The Noncommutative Standard Model and Forbidden Decays
In this contribution we discuss the Noncommutative Standard Model and the
associated Standard Model-forbidden decays that can possibly serve as an
experimental signature of space-time noncommutativity.Comment: 15 pages, 1 figure, Invited talk at 9th Adriatic Meeting and Central
European Symposia on Particle Physics and The Universe, Dubrovnik, Croatia,
4-14 Sep 200
From colored glass condensate to gluon plasma: equilibration in high energy heavy ion collisions
The initial distribution of gluons at the very early times after a high
energy heavy ion collision is described by the bulk scale of gluon
saturation in the nuclear wavefunction. The subsequent evolution of the system
towards kinetic equilibrium is described by a non-linear Landau equation for
the single particle distributions \cite{Mueller1,Mueller2}. In this paper, we
solve this equation numerically for the idealized initial conditions proposed
by Mueller, and study the evolution of the system to equilibrium. We discuss
the sensitivity of our results on the dynamical screening of collinear
divergences. In a particular model of dynamical screening, the convergence to
the hydrodynamic limit is seen to be rapid relative to hydrodynamic time
scales. The equilibration time, the initial temperature, and the chemical
potential are shown to have a strong functional dependence on the initial gluon
saturation scale .Comment: 34 pages, 10 figure
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