893 research outputs found
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Tuberculosis and poverty: the contribution of patient costs in sub-Saharan Africa â a systematic review
Background: Tuberculosis (TB) is known to disproportionately affect the most economically disadvantaged strata of society. Many studies have assessed the association between poverty and TB, but only a few have assessed the direct financial burden TB treatment and care can place on households. Patient costs can be particularly burdensome for TB-affected households in sub-Saharan Africa where poverty levels are high; these costs include the direct costs of medical and non-medical expenditures and the indirect costs of time utilizing healthcare or lost wages. In order to comprehensively assess the existing evidence on the costs that TB patients incur, we undertook a systematic review of the literature. Methods: PubMed, EMBASE, Science Citation Index, Social Science Citation Index, EconLit, Dissertation Abstracts, CINAHL, and Sociological Abstracts databases were searched, and 5,114 articles were identified. Articles were included in the final review if they contained a quantitative measure of direct or indirect patient costs for treatment or care for pulmonary TB in sub-Saharan Africa and were published from January 1, 1994 to Dec 31, 2010. Cost data were extracted from each study and converted to 2010 international dollars (I1 to almost I$600 or from a small fraction of mean monthly income for average annual income earners to over 10 times average annual income for income earners in the income-poorest 20% of the population. Out of the eleven types of TB patient costs identified in this review, the costs for hospitalization, medication, transportation, and care in the private sector were largest. Conclusion: TB patients and households in sub-Saharan Africa often incurred high costs when utilizing TB treatment and care, both within and outside of Directly Observed Therapy Short-course (DOTS) programs. For many households, TB treatment and care-related costs were considered to be catastrophic because the patient costs incurred commonly amounted to 10% or more of per capita incomes in the countries where the primary studies included in this review were conducted. Our results suggest that policies to decrease direct and indirect TB patient costs are urgently needed to prevent poverty due to TB treatment and care for those affected by the disease
New Constraints on Neutron Star Cooling from Chandra Observations of 3C58
3C58 is a young Crab-like supernova remnant. Historical evidence strongly
suggests an association of the remnant with supernova SN 1181, which would make
3C58 younger than the Crab Nebula. Recent Chandra observations have identified
the young 65 ms pulsar J0205+6449 at its center, embedded in a compact nebula
which, we show here, appears to be confined by the pulsar wind termination
shock. We present new Chandra observations of this compact nebula and embedded
pulsar which set strong upper limits on thermal emission originating from the
neutron star surface. These limits fall far below predictions of standard
neutron star cooling, requiring the presence of exotic cooling processes in the
neutron star core.Comment: 13 pages, 4 figures, accepted by ApJ Letter
New and improved demonstrations, each illustrating a single scientific paper
Thesis (Ed.M.)--Boston Universit
A Comparative Gene Map of the Horse (Equus caballus)
A comparative gene map of the horse genome composed of 127 loci was assembled based on the new assignment of 68 equine type I loci and on data published previously. PCR primers based on consensus gene sequences conserved across mammalian species were used to amplify markers for assigning 68 equine type I loci to 27 horse synteny groups established previously with a horse-mouse somatic cell hybrid panel (SCHP, UC Davis). This increased the number of coding genes mapped to the horse genome by over 2-fold and allowed refinements of the comparative mapping data available for this species. In conjunction with 57 previous assignments of type I loci to the horse genome map, these data have allowed us to confirm the assignment of 24 equine synteny groups to their respective chromosomes, to provisionally assign nine synteny groups to chromosomes, and to further refine the genetic composition established with Zoo-FISH of two horse chromosomes. The equine type I markers developed in this study provide an important resource for the future development of the horse linkage and physical genome maps
A Chandra Observation of the Diffuse Emission Centered on the Low Mass X-ray Binary 4U 1755-33
We present an analysis of a Chandra observation of the field surrounding the
low-mass X-ray binary 4U 1755-33, which has been in quiescence since 1996. In
2003, Angelini and White reported the appearance of a narrow 7 arcmin long
jetlike feature centered on the position of 4U 1755-33 using the XMM-Newton
telescope. Though the source and jet are not visibly apparent in our
Chandra/ACIS-S image, there is a significant excess (4-6 sigma) of counts in a
region that encloses the jet when compared to adjacent regions. We examined a
knot of emission in the jet that was detected by XMM-Newton but not by Chandra
and calculated that if the knot flux observed by XMM-Newton was concentrated in
a point source, Chandra would have easily detected it; we therefore conclude
that this knot of emission is diffuse. In summary, we suggest that the jetlike
feature found previously in the XMM-Newton data is quite diffuse and likely a
true jet, and is not due to a chance alignment of discrete point sources or
point-like regions of emission associated with internal shocks.Comment: 5 pages, color figures, uses emulateapj.cls and apjfonts.sty,
submitted to ApJ Letter
Discovery of X-ray Pulsations from the Compact Central Source in the Supernova Remnant 3C 58
We report on high time resolution observations of the SNR 3C 58 using the
High Resolution Camera on the Chandra X-ray Observatory. These data show a
point-like central source, from which we detect 65.68 ms pulsations at 6.7
sigma significance. We interpret these pulsations as corresponding to a young
rotation-powered pulsar (PSR J-205+6449) which is associated with, and powers,
3C 58. Analysis of archival RXTE data from three years earlier confirms these
pulsations, and allows us to determine a spin-down rate of P-dot=1.93x10^-13
s/s. Assuming a magnetic dipole model for PSR J0205+6449, we infer a surface
magnetic field of 3.6x10^12 G. The characteristic age for this pulsar is 5400
yr, indicating either that 3C 58 was not the supernova of 1181 CE, or that the
pulsar's initial spin period was ~60 ms.Comment: 11 pages, 4 figures, 1 tabl
X-ray and Radio Variability of M31*, The Andromeda Galaxy Nuclear Supermassive Black Hole
We confirm our earlier tentative detection of M31* in X-rays and measure its
light-curve and spectrum. Observations in 2004-2005 find M31* rather quiescent
in the X-ray and radio. However, X-ray observations in 2006-2007 and radio
observations in 2002 show M31* to be highly variable at times. A separate
variable X-ray source is found near P1, the brighter of the two optical nuclei.
The apparent angular Bondi radius of M31* is the largest of any black hole, and
large enough to be well resolved with Chandra. The diffuse emission within this
Bondi radius is found to have an X-ray temperature ~0.3 keV and density 0.1
cm-3, indistinguishable from the hot gas in the surrounding regions of the
bulge given the statistics allowed by the current observations. The X-ray
source at the location of M31* is consistent with a point source and a power
law spectrum with energy slope 0.9+/-0.2. Our identification of this X-ray
source with M31* is based solely on positional coincidence.Comment: 25 pages, 8 figures, submitted to Ap
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Imbalance in the response of pre- and post-synaptic components to amyloidopathy
Alzheimerâs disease (AD)-associated synaptic dysfunction drives the progression of pathology from its earliest stages. AÎČ species, both soluble and in plaque deposits, have been causally related to the progressive, structural and functional impairments observed in AD. It is, however, still unclear how AÎČ plaques develop over time and how they progressively affect local synapse density and turnover. Here we observed, in a mouse model of AD, that AÎČ plaques grow faster in the earlier stages of the disease and if their initial area is > 500 ”m2; this may be due to deposition occurring in the cloud part of the plaque. In addition, synaptic turnover is higher in the presence of amyloid pathology and this is paralleled by a reduction in pre- but not post-synaptic densities. Plaque proximity does not appear to have an impact on synaptic dynamics. These observations indicate an imbalance in the response of the pre- and post-synaptic terminals and that therapeutics, alongside targeting the underlying pathology, need to address changes in synapse dynamics
Two New X-ray/Optical/Radio Supernova Remnants in M31
We compare a deep (37 ks) Chandra ACIS-S image of the M31 bulge to Local
Group Survey narrow-band optical data and Very Large Array (VLA) radio data of
the same region. Our precisely registered images reveal two new optical shells
with X-ray counterparts. These shells have sizes, [S II]/H-alpha flux ratios,
and X-ray spectral properties typical of supernova remnants (SNRs) with ages of
9 and 17 kyr. Analysis of complementary VLA data
reveals the radio counterparts, further confirming that they are SNRs. We
discuss and compare the properties and morphologies of these SNRs at the
different wavelengths.Comment: 18 pages, 5 figures, accepted for publication in Ap
\u3ci\u3eA Pictorial History of Bryant University: 1989-2018 An Era of Transformation\u3c/i\u3e
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