383 research outputs found
Project question : are there cost effectiveness to contracting out our food services program
The purpose of this project is to determine if there is a more cost effective method of providing nutritious and appealing meals to the children and staff of John de
la Howe School
HIV and the brain: from AIDS to old age
The field of HIV medicine has changed rapidly in the last two decades since effective and tolerable antiretroviral treatment became available. As a result, although classical opportunistic infections of the brain have become less common, clinicians need to be aware of a wider range of acute and chronic complications of HIV and its treatment. In this article, we summarise major opportunistic infections, immune reconstitution inflammatory syndrome, HIV-associated neurocognitive disorders, and cerebrovascular disease in HIV positive patients. We also emphasise the preventability and reversibility of most of the central nervous system complications of HIV, and hence the importance of early diagnosis of HIV and involvement of clinicians with special expertise in HIV medicine
Bullying and school disruption assessment: studies with Portuguese adolescent students
Problem Statement: The question of bullying and school disruptive behavior has emerged as a powerful issue in Portuguese
educational context. The lack of evaluation instruments, with studied psychometric characteristics, has constituted a problem.
Purpose of Study: School disruption and bullying assessment, in Portuguese adolescents, was the focus of this research.
Research Methods: The psychometric qualities — internal consistency and the external validity — were analyzed in different
scales.
Findings: The analyses carried out confirm the scales as reliable and valid instruments. Conclusions: These instruments may be
a useful avenue for teachers, psychologists and other education professionals
Cross-Sectional Study of Unexplained White Matter Lesions in HIV Positive Individuals Undergoing Brain Magnetic Resonance Imaging.
Abstract White matter (WM) abnormalities are frequently seen on brain MRI of HIV positive (HIV+) patients. We aimed to determine the prevalence of unexplained WM abnormalities and their associations with HIV disease and cardiovascular risk factors. We conducted a retrospective, cross-sectional study of brain MRI of HIV+ patients conducted between 2004 and 2009 at our center. Clinical and laboratory data were compiled, and images were independently reviewed for WM lesions. Images were obtained from 254 patients: 70% male, 53% white, 40% black, mean age 42 years, median current CD4 count 240 cells/mm(3), and 41% not taking antiretroviral therapy (ART). Hyperintense WM lesions were present in 161 patients (63.4%): 89 scans (35.0%) showed diffuse WM signal abnormality (DWMSA), 61 (24.0%) were consistent with small vessel disease (SVD, graded by Fazekas' scale), and 37 (14.6%) showed large asymmetrical focal WM lesions. SVD changes were associated with age and cardiovascular risk factors, and while cerebral SVD may be related to HIV infection, the MRI findings were not associated with HIV-related factors. The only risk factor for DWMSA was black race, and no correlation with cardiovascular risk factors, CD4 count, or clinical presentation was identified. DWMSA are therefore of uncertain neurological significance in HIV+ patients and could represent more than one clinicopathological entity
Routine detection and management of neurocognitive impairment in HIV-positive patients in a UK centre
We estimated the burden of HIV-associated neurocognitive disorders (HAND) in a UK clinic. From a random sample, and referrals to specialist services over one year (neurology, clinical psychology, hospital admissions), we determined whether patients were diagnosed with HIV-associated dementia (HAD) and whether they reported symptoms suggesting neurocognitive impairment (NCI). In the first sample, 2/150 (prevalence 1.3%; 95% confidence interval [CI] 0.2-4.7%) had documented HAD. Eleven patients (7.3%; CI 3.7-12.7%) reported recent symptoms suggesting NCI; most of these individuals were diagnosed with a psychiatric or substance-use disorder. Among specialist referrals with symptoms suggesting NCI, 11 were diagnosed with HAD from a clinic population of 3129 individuals (annual incidence 0.4%; CI 0.2-0.6%). No patients with mildly symptomatic or asymptomatic HAND were identified in either sample, suggesting that such patients remain undetected in current clinical practice. Evidence-based screening for HAND in HIV clinics may be needed
Interstellar Dust Close to the Sun
The low density interstellar medium (ISM) close to the Sun and inside of the
heliosphere provides a unique laboratory for studying interstellar dust grains.
Grain characteristics in the nearby ISM are obtained from observations of
interstellar gas and dust inside of the heliosphere and the interstellar gas
towards nearby stars. Comparison between the gas composition and solar
abundances suggests that grains are dominated by olivines and possibly some
form of iron oxide. Measurements of the interstellar Ne/O ratio by the
Interstellar Boundary Explorer spacecraft indicate that a high fraction of
interstellar oxygen in the ISM must be depleted onto dust grains. Local
interstellar abundances are consistent with grain destruction in ~150 km/s
interstellar shocks, provided that the carbonaceous component is hydrogenated
amorphous carbon and carbon abundances are correct. Variations in relative
abundances of refractories in gas suggest variations in the history of grain
destruction in nearby ISM. The large observed grains, > 1 micron, may indicate
a nearby reservoir of denser ISM. Theoretical three-dimensional models of the
interaction between interstellar dust grains and the solar wind predict that
plumes of about 0.18 micron dust grains form around the heliosphere.Comment: 2011 AGOS Taiwan meeting; accepted for publication in Earth, Planets
and Spac
Mid- to Far-Infrared spectroscopy of Sharpless 171
We have collected one-dimensional raster-scan observations of the active
star-forming region Sharpless 171 (S171), a typical HII region-molecular cloud
complex, with the three spectrometers (LWS, SWS, and PHT-S) on board ISO. We
have detected 8 far-infrared fine-structure lines, [OIII] 52um, [NIII] 57um,
[OI] 63um, [OIII] 88um, [NII] 122um, [OI] 146um, [CII] 158um, and [SiII] 35um
together with the far-infrared continuum and the H2 pure rotation transition
(J=5-3) line at 9.66um. The physical properties of each of the three phases
detected, highly-ionized, lowly-ionized and neutral, are investigated through
the far-infrared line and continuum emission. Toward the molecular region,
strong [OI] 146um emission was observed and the [OI] 63um to 146um line ratio
was found to be too small (about 5) compared to the values predicted by current
photodissociation region (PDR) models. We examine possible mechanisms to
account for the small line ratio and conclude that the absorption of the [OI]
63um and the [CII] 158um emission by overlapping PDRs along the line of sight
can account for the observations and that the [OI] 146um emission is the best
diagnostic line for PDRs. We propose a method to estimate the effect of
overlapping clouds using the far-infrared continuum intensity and derive the
physical properties of the PDR. The [SiII] 35um emission is quite strong at
almost all the observed positions. The correlation with [NII] 122um suggests
that the [SiII] emission originates mostly from the ionized gas. The [SiII]
35um to [NII] 122um ratio indicates that silicon of 30% of the solar abundance
must be in the diffuse ionized gas, suggesting that efficient dust destruction
is undergoing in the ionized region.Comment: 15 pages with 15 figures, accepted in Astronomy & Astrophysic
Reduced Na+ and higher K+ channel expression and function contribute to right ventricular origin of arrhythmias in Scn5a+/− mice
Brugada syndrome (BrS) is associated with ventricular tachycardia originating particularly in the right ventricle (RV). We explore electrophysiological features predisposing to such arrhythmic tendency and their possible RV localization in a heterozygotic Scn5a+/− murine model. Nav1.5 mRNA and protein expression were lower in Scn5a+/− than wild-type (WT), with a further reduction in the RV compared with the left ventricle (LV). RVs showed higher expression levels of Kv4.2, Kv4.3 and KChIP2 in both Scn5a+/− and WT. Action potential upstroke velocity and maximum Na+ current (INa) density were correspondingly decreased in Scn5a+/−, with a further reduction in the RV. The voltage dependence of inactivation was shifted to more negative values in Scn5a+/−. These findings are predictive of a localized depolarization abnormality leading to slowed conduction. Persistent Na+ current (IpNa) density was decreased in a similar pattern to INa. RV transient outward current (Ito) density was greater than LV in both WT and Scn5a+/−, and had larger time constants of inactivation. These findings were also consistent with the observation that AP durations were smallest in the RV of Scn5a+/−, fulfilling predictions of an increased heterogeneity of repolarization as an additional possible electrophysiological mechanism for arrhythmogenesis in BrS
Observation of interstellar lithium in the low-metallicity Small Magellanic Cloud
The primordial abundances of light elements produced in the standard theory
of Big Bang nucleosynthesis (BBN) depend only on the cosmic ratio of baryons to
photons, a quantity inferred from observations of the microwave background. The
predicted primordial 7Li abundance is four times that measured in the
atmospheres of Galactic halo stars. This discrepancy could be caused by
modification of surface lithium abundances during the stars' lifetimes or by
physics beyond the Standard Model that affects early nucleosynthesis. The
lithium abundance of low-metallicity gas provides an alternative constraint on
the primordial abundance and cosmic evolution of lithium that is not
susceptible to the in situ modifications that may affect stellar atmospheres.
Here we report observations of interstellar 7Li in the low-metallicity gas of
the Small Magellanic Cloud, a nearby galaxy with a quarter the Sun's
metallicity. The present-day 7Li abundance of the Small Magellanic Cloud is
nearly equal to the BBN predictions, severely constraining the amount of
possible subsequent enrichment of the gas by stellar and cosmic-ray
nucleosynthesis. Our measurements can be reconciled with standard BBN with an
extremely fine-tuned depletion of stellar Li with metallicity. They are also
consistent with non-standard BBN.Comment: Published in Nature. Includes main text and Supplementary
Information. Replaced with final title and abstrac
Origin and evolution of the light nuclides
After a short historical (and highly subjective) introduction to the field, I
discuss our current understanding of the origin and evolution of the light
nuclides D, He-3, He-4, Li-6, Li-7, Be-9, B-10 and B-11. Despite considerable
observational and theoretical progress, important uncertainties still persist
for each and every one of those nuclides. The present-day abundance of D in the
local interstellar medium is currently uncertain, making it difficult to infer
the recent chemical evolution of the solar neighborhood. To account for the
observed quasi-constancy of He-3 abundance from the Big Bang to our days, the
stellar production of that nuclide must be negligible; however, the scarce
observations of its abundance in planetary nebulae seem to contradict this
idea. The observed Be and B evolution as primaries suggests that the source
composition of cosmic rays has remained quasi-constant since the early days of
the Galaxy, a suggestion with far reaching implications for the origin of
cosmic rays; however, the main idea proposed to account for that constancy,
namely that superbubbles are at the source of cosmic rays, encounters some
serious difficulties. The best explanation for the mismatch between primordial
Li and the observed "Spite-plateau" in halo stars appears to be depletion of Li
in stellar envelopes, by some yet poorly understood mechanism. But this
explanation impacts on the level of the recently discovered early ``Li-6
plateau'', which (if confirmed), seriously challenges current ideas of cosmic
ray nucleosynthesis.Comment: 18 pages, 9 figs. Invited Review in "Symposium on the Composition of
Matter", honoring Johannes Geiss on the occasion of his 80th birthday
(Grindelwald, Switzerland, Sept. 2006), to be published in Space Science
Series of ISS
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