596 research outputs found
Effects of confinement on the permanent electric-dipole moment of Xe atoms in liquid Xe
Searches for permanent electric-dipole moments (EDM) of atoms provide
important constraints on competing extensions to the standard model of
elementary particles. Recently proposed experiment with liquid Xe [M.V.
Romalis and M.P. Ledbetter, Phys. Rev. Lett. \textbf{87}, 067601 (2001)] may
significantly improve present limits on the EDMs. To interpret experimental
data in terms of CP-violating sources, one must relate measured atomic EDM to
various model interactions via electronic-structure calculations. Here we study
density dependence of atomic EDMs. The analysis is carried out in the framework
of the cell model of the liquid coupled with relativistic atomic-structure
calculations. We find that compared to an isolated atom, the EDM of an atom of
liquid Xe is suppressed by about 40%
Statistical analysis of environmental variability within the CELSS breadboard project's biomass production chamber
Variability in the aerial and root environments of NASA's Breadboard Project's Biomass Production Chamber (BPC) was determined. Data from two lettuce and two potato growouts were utilized. One growout of each crop was conducted prior to separating the upper and lower chambers; the other was subsequent to separation. There were little or no differences in pH, EC, or solution temperature between the upper and lower chamber or within a chamber. Variation in the aerial environment within a chamber was two to three times greater than variation between chambers for air temperature, relative humidity, and PPF. High variability in air velocity, relative to tray position, was observed. Separating the BPC had no effect on PPF, air velocity, solution temperature, pH, or EC. Separation reduced the gradient in air temperature and relative humidity between the upper and lower chambers, but increased the variability within a chamber. Variation between upper and lower chambers was within 5 percent of environmental set-points and of little or no physiological significance. In contrast, the variability within a chamber limits the capability of the BPC to generate statistically reliable data from individual tray treatments at this time
A Randomized Clinical Trial of Vapocoolant for Pediatric Immunization Pain Relief
OBJECTIVES: The purpose of the current study was to evaluate the effectiveness of vapocoolant for preschoolers’ immunization injection pain relief.
STUDY DESIGN: 57 4- to 6-year-old children were randomized to vapocoolant alone or typical care conditions. Pain was measured at baseline and at injection via self-report, caregiver-report, nurse-report, and an observational scale.
RESULTS: Self-report suggested that children in the vapocoolant alone condition demonstrated stronger increases in pain from baseline to injection than typical care. All other measures showed significant increases in pain from baseline to injection, but none indicted treatment effects.
CONCLUSIONS: Consistent with prior studies, vapocoolant might not be an effective pain-management intervention for children’s intramuscular injections
Randomized Clinical Trial of Distraction for Infant Immunization Pain
Distraction has been shown to be an effective technique for managing pain in children; however, few investigations have examined the utility of this technique with infants. The goal of the current study was to investigate the effectiveness of movie distraction in reducing infants’ immunization distress. Participants were 136 infants (range = 1 to 21 months; M = 7.6 months, SD = 5.0 months) and their parents, all of whom were recruited when presenting for routine vaccinations. The parent-child dyads were randomly assigned to either a Distraction or Typical Care control condition. Infant and adult behaviors were assessed using a visual analog scale and a behavioral observation rating scale. Results indicated parents in the Distraction group engaged in higher rates of distraction than those in the Typical Care group, whereas there was no difference in the behavior of nurses in the Distraction and Typical Care groups. In addition, infants in the Distraction group displayed fewer distress behaviors than infants in the Typical Care group both prior to and during recovery from the injection. Findings suggest that a simple and practical distraction intervention can provide some distress relief to infants during routine injections
Solar Jet Hunter: a citizen science initiative to identify coronal jets in EUV data sets
Context. Solar coronal jets seen in EUV are ubiquitous on the Sun, have been
found in and at the edges of active regions, at the boundaries of coronal
holes, and in the quiet Sun. Jets have various shapes, sizes, brightness,
velocities and duration in time, which complicates their detection by automated
algorithms. So far, solar jets reported in the Heliophysics Event Knowledgebase
(HEK) have been mostly reported by humans looking for them in the data, with
different levels of precision regarding their timing and positions. Aims. We
create a catalogue of solar jets observed in EUV at 304 {\AA} containing
precise and consistent information on the jet timing, position and extent.
Methods. We designed a citizen science project, "Solar Jet Hunter", on the
Zooniverse platform, to analyze EUV observations at 304 {\AA} from the Solar
Dynamic Observatory/Atmospheric Imaging Assembly (SDO/AIA). We created movie
strips for regions of the Sun in which jets have been reported in HEK and ask
the volunteers to 1) confirm the presence of at least one jet in the data and
2) report the timing, position and extent of the jet. Results. We report here
the design of the project and the results obtained after the analysis of data
from 2011 to 2016. 365 "coronal jet" events from HEK served as input for the
citizen science project, equivalent to more than 120,000 images distributed
into 9,689 "movie strips". Classification by the citizen scientists resulted
with only 21% of the data containing a jet, and 883 individual jets being
identified. Conclusions. We demonstrate how citizen science can enhance the
analysis of solar data with the example of Solar Jet Hunter. The catalogue of
jets thus created is publicly available and will enable statistical studies of
jets and related phenomena. This catalogue will also be used as a training set
for machines to learn to recognize jets in further data sets
Constraints on Gamma-ray Emission from the Galactic Plane at 300 TeV
We describe a new search for diffuse ultrahigh energy gamma-ray emission
associated with molecular clouds in the galactic disk. The Chicago Air Shower
Array (CASA), operating in coincidence with the Michigan muon array (MIA), has
recorded over 2.2 x 10^{9} air showers from April 4, 1990 to October 7, 1995.
We search for gamma rays based upon the muon content of air showers arriving
from the direction of the galactic plane. We find no significant evidence for
diffuse gamma-ray emission, and we set an upper limit on the ratio of gamma
rays to normal hadronic cosmic rays at less than 2.4 x 10^{-5} at 310 TeV (90%
confidence limit) from the galactic plane region: (50 degrees < l < 200
degrees); -5 degrees < b < 5 degrees). This limit places a strong constraint on
models for emission from molecular clouds in the galaxy. We rule out
significant spectral hardening in the outer galaxy, and conclude that emission
from the plane at these energies is likely to be dominated by the decay of
neutral pions resulting from cosmic rays interactions with passive target gas
molecules.Comment: Astrophysical Journal, submitted, 11 pages, AASTeX Latex, 3
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