8,896 research outputs found
Angle-Resolved Photoemission of Solvated Electrons in Sodium-Doped Clusters
Angle-resolved photoelectron spectroscopy of the unpaired electron in
sodium-doped water, methanol, ammonia, and dimethyl ether clusters is
presented. The experimental observations and the complementary calculations are
consistent with surface electrons for the cluster size range studied. Evidence
against internally solvated electrons is provided by the photoelectron angular
distribution. The trends in the ionization energies seem mainly determined by
the degree of hydrogen bonding in the solvent and the solvation of the ion
core. The onset ionization energies of water and methanol clusters do not level
off at small cluster sizes, but decrease slightly with increasing cluster size
The role of microstructure and processing on the proton conducting properties of gadolinium-doped barium cerate
The influence of grain boundary conductivity and microstructure on the electrical properties of BaCe0.85Gd0.15O3-d have been examined. Grain sizes were varied by sintering at various temperatures. Impedance data were analyzed using the brick layer model, and some new consequences of this model are presented. The specific grain boundary conductivity exhibits an activation energy of ~0.7eV, and for similar processing routes, is independent of grain size. An isotope effect was observed, indicating that protons (or deuterons) are the mobile species. TEM investigations showed the intergranular regions to be free of any glassy phase that could account for the differences in bulk and grain boundary properties. Single crystal fibers, grown by a modified float zone process, were notably barium deficient, and exhibited a low conductivity, comparable to that of polycrystalline Ba0.96Ce0.85Gd0.15O3-ÎŽ
Exploring infection prevention and control knowledge and beliefs in the Solomon Islands using Photovoice
Healthcare associated infections are the most common complication of a personâs hospital stay. Contemporary infection prevention and control programs are universally endorsed to prevent healthcare associated infections. However, western biomedical science on which contemporary infection prevention and control is based, is not the only way that staff and patients within healthcare settings understand disease causation and/or disease transmission. This results paper reports on one aspect of a study which ascertains perceptions of disease transmission and how these influence infection prevention and control practice at Atoifi Adventist Hospital Solomon Islands. Photovoice was used as the primary data collection method with staff and patients. The germ theory and hospital hygiene processes were only one of many explanations of disease transmission at the hospital. Many social, cultural and spiritual influences played an important role in how people understood disease to be transmitted. Although infection prevention and control models based on western science continue to form the premise of reducing healthcare associated infections in Solomon Islands and locations across the globe, local social, cultural and spiritual beliefs need to be considered when planning and implementing infection prevention and control programs to ensure success
Solutions to infection prevention and control challenges in developing countries, do they exist? An integrative review
Implementing sustainable infection prevention and control (IP&C) programs in developing countries is challenging. Many developing countries experience high burdens of disease and political instability. In addition, they are affected by geographical and climatic challenges, and have unique social, cultural and spiritual beliefs, all of which contribute to a higher prevalence of infections. The aim of this integrative review is to identify existing solutions to the challenges faced by developing countries when implementing IP&C programs. An extensive literature review was conducted to explore improvements in infection control in rural hospitals in developing countries. Three electronic databases were searched for relevant articles written between 1980 and 2018, published in peer reviewed English language journals, and relating to hospitals, not community settings. The findings indicate that developing countries continue to face many challenges in implementing IP&C programs. Limited success has been described with some IP&C program components but it is clear that little original research on the topic exists. Notably scarce are studies on the influences that culture, religious and spiritual beliefs have on IP&C program implementation. This review highlights opportunities for further research into healthcare workers perceptions of disease causation and infection transmission, and the role this plays in the effective implementation of an IP&C program. By exploring these opportunities appropriate and culturally sensitive solutions may be identified, which can assist with the design and implementation of culturally relevant IP&C programs in these settings
The ACS Fornax Cluster Survey. II. The Central Brightness Profiles of Early-Type Galaxies: A Characteristic Radius on Nuclear Scales and the Transition from Central Luminosity Deficit to Excess
We analyse HST surface brightness profiles for 143 early-type galaxies in the
Virgo and Fornax Clusters. Sersic models provide accurate descriptions of the
global profiles with a notable exception: the observed profiles deviate
systematically inside a characteristic "break" radius of R_b ~ 0.02R_e where
R_e is the effective radius of the galaxy. The sense of the deviation is such
that bright galaxies (M_B < -20) typically show central light deficits with
respect to the inward extrapolation of the Sersic model, while the great
majority of low- and intermediate-luminosity galaxies (-19.5 < M_B < -15) show
central light excesses; galaxies occupying a narrow range of intermediate
luminosities (-20 < M_B < -19.5) are usually well fitted by Sersic models over
all radii. The slopes of the central surface brightness profiles, when measured
at fixed fractions of R_e, vary smoothly as a function of galaxy luminosity in
a manner that depends sensitively on the choice of measurement radius. We show
that a recent claim of strong bimodality in slope is likely an artifact of the
galaxy selection function used in that study. To provide a more robust
characterization of the inner regions of galaxies, we introduce a parameter
that describes the central luminosity deficit or excess relative to the inward
extrapolation of the outer Sersic model. We find that this parameter varies
smoothly over the range of ~ 720 in blue luminosity spanned by the Virgo and
Fornax sample galaxies, with no evidence for a dichotomy. We argue that the
central light excesses (nuclei) in M_B > -19 galaxies may be the analogs of the
dense central cores that are predicted by some numerical simulations to form
via gas inflows. (ABRIDGED)Comment: To appear in the Astrophysical Journal, December 2007. Full
resolution paper available at
http://www.cfa.harvard.edu/~ajordan/ACSFCS/Home.htm
Reliability of a 2-Bout exercise test on a Wattbike cycle ergometer
Purpose: To determine the intraday and interday reliability of a 2 Ă 4-min performance test on a cycle ergometer (Wattbike) separated by 30 min of passive recovery (2 Ă 4MMP). Methods: Twelve highly trained cyclists (mean ± SD; age = 20 ± 2 y, predicted VO2max = 59.0 ± 3.6 mL · kgâ1 · minâ1) completed six 2 Ă 4MMP cycling tests on a Wattbike ergometer separated by 7 d. Mean power was measured to determine intraday (test 1 [T1] to test 2 [T2]) and interday reliability (weeks 1â6) over the repeated trials. Results: The mean intraday reliabilities of the 2 Ă 4MMP test, as expressed by the typical error of measurement (TEM, W) and coefficient of variation (CV, %) over the 6 wk, were 10.0 W (95% confidence limits [CL] 8.2â11.8), and 2.6% (95%CL 2.1â3.1), respectively. The mean interday reliability TEM and CV for T1 over the 6 wk were 10.4 W (95%CL 8.7â13.3) and 2.7% (95%CL 2.3â3.5), respectively, and 11.7 W (95%CL 9.8â15.1) and 3.0% (95%CL 2.5â3.9) for T2. Conclusion: The testing protocol performed on a Wattbike cycle ergometer in the current study is reproducible in highly trained cyclists. The high intraday and interday reliability make it a reliable method for monitoring cycling performance and for investigating factors that affect performance in cycling events
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Environmental and genetic factors affecting seed set in Dactylis glomerata L.
Field, growth chamber, and greenhouse studies were carried
out to evaluate factors that cause low seed set in Dactylis Glomerata
L. The variety, 'Latar', and the parental clones of the variety,
'Pennlate', were studied in detail.
Floral anatomy investigations indicated that 98 percent of
Dactylis flowers opened at Corvallis in 1968 and that non-necrotic
ovaries were present in 96.5 percent of the florets. The variety,
'Latar', and clone 'R' from 'Pennlate' which showed more necrotic
ovaries at flowering time than the other types examined were also
lower in seed set. Abnormal stigmatic bending was found to be
associated with low seed set clonal types; reduced stigmatic area was
found to be partially responsible for low seed set in these clones.
Clonal types set slightly more seed at 82 F than at 72 F in a
growth chamber. Plants maintained at 20 atmospheres of moisture
stress at flowering time set significantly less seed than plants
maintained at 12.5 atmospheres of stress. Greenhouse studies indicated
that Dactylis seed set was significantly reduced by moisture
stress during the flowering period but not by moisture stress shortly
after heading or during the five day period after flowering.
Forty-one 'Latar' plants from field grown material had a
chromosome count of 2n = 28 which indicated that this low seed set
variety did not contain a large number of aneuploid plants. Evidence
for genetic irregularity was found in other aspects of the research.
Examination of microsporocytes in clone 'R' revealed that ten percent
of the metaphase cells showed lagging chromosomes, chromosome
fragments, and bridges. A significant correlation between
normal pollen and seed set was found in 616 heads from 43 commercial
varieties grown at Corvallis in 1969. Genetic instability may
have been responsible for both pollen and ovule abortion. Plants
with a normal pollen rating of 91 percent or over had seed set six
percent greater than the population mean.
Significant differences were found in seed set between clonal
types which indicated that some clones were more fertile than others.
Significant year-to-year differences in seed set were found within
clones; genetic environmental interactions were apparently responsible
for these fertility differences.
This research indicated that some Dactylis varieties grown
for seed in Oregon were low in seed set and procedures were worked out for identifying the infertility in varieties. Screening clonal
materials in polycross nurseries to remove infertile types was suggested as a way of increasing seed set in commercial varieties
Management of COPD in the UK primary-care setting : an analysis of real-life prescribing patterns
Peer reviewedPublisher PD
The ACS Virgo Cluster Survey II. Data Reduction Procedures
The ACS Virgo Cluster Survey is a large program to carry out multi-color
imaging of 100 early-type members of the Virgo Cluster using the Advanced
Camera for Surveys (ACS) on the Hubble Space Telescope. Deep F475W and F850LP
images (~ SDSS g and z) are being used to study the central regions of the
program galaxies, their globular cluster systems, and the three-dimensional
structure of Virgo itself. In this paper, we describe in detail the data
reduction procedures used for the survey, including image registration,
drizzling strategies, the computation of weight images, object detection, the
identification of globular cluster candidates, and the measurement of their
photometric and structural parameters.Comment: 33 pages, 8 figures. Accepted for publication in ApJS. Also available
at http://www.physics.rutgers.edu/~pcote/acs/publications.htm
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