1,691 research outputs found
Integrating tuberculosis and HIV care in the primary care setting in South Africa.
BACKGROUND: In many countries including South Africa, the increasing human immunodeficiency virus (HIV) and tuberculosis (TB) epidemics have impacted significantly on already weakened public health services. This paper reviews the scope, process and performance of the HIV and TB services in a primary care setting where antiretroviral therapy is provided, in Khayelitsha, South Africa, in order to assess whether there is a need for some form of integration. METHODS: The scope and process of both services were assessed through observations of the service and individual and group interviews with key persons. The performance was assessed by examining the 2001-2002 reports from the health information system and clinical data. RESULTS: The TB service is programme oriented to the attainment of an 85% cure rate amongst smear-positive patients while the HIV service has a more holistic approach to the patient with HIV. The TB service is part of a well-established programme that is highly standardized. The HIV service is in the pilot phase. There is a heavy load at both services and there is large degree of cross-referral between the two services. There are lessons that can be learnt from each service. There is an overlap of activities, duplication of services and under-utilization of staff. There are missed opportunities for TB and HIV prevention, diagnosis and management. CONCLUSIONS: The study suggests that there may be benefits to integrating HIV and TB services. Constraints to this process are discussed
Spectral/hp element methods: recent developments, applications, and perspectives
The spectral/hp element method combines the geometric flexibility of the
classical h-type finite element technique with the desirable numerical
properties of spectral methods, employing high-degree piecewise polynomial
basis functions on coarse finite element-type meshes. The spatial approximation
is based upon orthogonal polynomials, such as Legendre or Chebychev
polynomials, modified to accommodate C0-continuous expansions. Computationally
and theoretically, by increasing the polynomial order p, high-precision
solutions and fast convergence can be obtained and, in particular, under
certain regularity assumptions an exponential reduction in approximation error
between numerical and exact solutions can be achieved. This method has now been
applied in many simulation studies of both fundamental and practical
engineering flows. This paper briefly describes the formulation of the
spectral/hp element method and provides an overview of its application to
computational fluid dynamics. In particular, it focuses on the use the
spectral/hp element method in transitional flows and ocean engineering.
Finally, some of the major challenges to be overcome in order to use the
spectral/hp element method in more complex science and engineering applications
are discussed
Nanometer-scale sharpness in corner-overgrown heterostructures
A corner-overgrown GaAs/AlGaAs heterostructure is investigated with
transmission and scanning transmission electron microscopy, demonstrating
self-limiting growth of an extremely sharp corner profile of 3.5 nm width. In
the AlGaAs layers we observe self-ordered diagonal stripes, precipitating
exactly at the corner, which are regions of increased Al content measured by an
XEDS analysis. A quantitative model for self-limited growth is adapted to the
present case of faceted MBE growth, and the corner sharpness is discussed in
relation to quantum confined structures. We note that MBE corner overgrowth
maintains nm-sharpness even after microns of growth, allowing the realization
of corner-shaped nanostructures.Comment: 4 pages, 3 figure
LR characterization of chirotopes of finite planar families of pairwise disjoint convex bodies
We extend the classical LR characterization of chirotopes of finite planar
families of points to chirotopes of finite planar families of pairwise disjoint
convex bodies: a map \c{hi} on the set of 3-subsets of a finite set I is a
chirotope of finite planar families of pairwise disjoint convex bodies if and
only if for every 3-, 4-, and 5-subset J of I the restriction of \c{hi} to the
set of 3-subsets of J is a chirotope of finite planar families of pairwise
disjoint convex bodies. Our main tool is the polarity map, i.e., the map that
assigns to a convex body the set of lines missing its interior, from which we
derive the key notion of arrangements of double pseudolines, introduced for the
first time in this paper.Comment: 100 pages, 73 figures; accepted manuscript versio
Racial Differences in Tuberculosis Infection in United States Communities: The Coronary Artery Risk Development in Young Adults Study
Previously reported associations between race/ethnicity and tuberculosis infection have lacked sufficient adjustment for socioeconomic factors. We analyzed race/ethnicity and self-reported tuberculosis infection data from the Coronary Artery Risk Development in Young Adults (CARDIA) study, a well-characterized cohort of 5115 black and white participants, and found that after adjusting for sociodemographic and clinical factors, black participants were more likely to report tuberculosis infection and/or disease (odds ratio, 2.0; 95% confidence interval, 1.5–2.9)
Global investments and regional development trajectories: the missing links
Global investments and regional development trajectories: the missing links. Regional Studies. Regional economic development has been long conceptualized as a non-linear, interactive and socially embedded process: these features were traditionally regarded as spatially mediated and highly localized. However, unprecedentedly fast technological change coupled with the intensification of global economic integration has spurred the need to place regional development in a truly open and interdependent framework. Despite substantial progress in the academic literature, rethinking regional development in this perspective still presents a number of challenges in terms of concepts, empirical evidence and policy approaches. Following an interdisciplinary assessment of how openness and connectivity – proxied by one of the many cross-border flows, i.e., global investments – interact with regional economic development trajectories, this paper presents a picture of the geography of foreign investments from and to the European regions and its change after the financial and economic crisis in 2008. This simple exercise sheds some initial light on how the operationalization of regional connectivity can improve one’s empirical understanding of the evolution of regional economies and the policy approach needed to support their reaction to change
A Multi-telescope Campaign on FRB 121102: Implications for the FRB Population
We present results of the coordinated observing campaign that made the first
subarcsecond localization of a Fast Radio Burst, FRB 121102. During this
campaign, we made the first simultaneous detection of an FRB burst by multiple
telescopes: the VLA at 3 GHz and the Arecibo Observatory at 1.4 GHz. Of the
nine bursts detected by the Very Large Array at 3 GHz, four had simultaneous
observing coverage at other observatories. We use multi-observatory constraints
and modeling of bursts seen only at 3 GHz to confirm earlier results showing
that burst spectra are not well modeled by a power law. We find that burst
spectra are characterized by a ~500 MHz envelope and apparent radio energy as
high as erg. We measure significant changes in the apparent
dispersion between bursts that can be attributed to frequency-dependent
profiles or some other intrinsic burst structure that adds a systematic error
to the estimate of DM by up to 1%. We use FRB 121102 as a prototype of the FRB
class to estimate a volumetric birth rate of FRB sources Mpc yr, where is the number of bursts per
source over its lifetime. This rate is broadly consistent with models of FRBs
from young pulsars or magnetars born in superluminous supernovae or long
gamma-ray bursts, if the typical FRB repeats on the order of thousands of times
during its lifetime.Comment: 17 pages, 7 figures. Submitted to AAS Journal
iPTF16fnl: a faint and fast tidal disruption event in an E+A galaxy
We present ground-based and \textit{Swift} observations of iPTF16fnl, a
likely tidal disruption event (TDE) discovered by the intermediate Palomar
Transient Factory (iPTF) survey at 66.6 Mpc. The lightcurve of the object
peaked at absolute mag. The maximum bolometric luminosity (from
optical and UV) was erg/s, an
order of magnitude fainter than any other optical TDE discovered so far. The
luminosity in the first 60 days is consistent with an exponential decay, with
, where =~57631.0 (MJD) and
days. The X-ray shows a marginal detection at erg/s (\textit{Swift} X-ray Telescope). No radio counterpart was
detected down to 3, providing upper limits for monochromatic radio
luminosity of erg/s and erg/s (VLA, 6.1 and 22 GHz). The blackbody temperature, obtained from
combined \textit{Swift} UV and optical photometry, shows a constant value of
19,000 K. The transient spectrum at peak is characterized by broad He II and
H emission lines, with an FWHM of about 14,000 km/s and 10,000 km/s
respectively. He I lines are also detected at 5875 and 6678.
The spectrum of the host is dominated by strong Balmer absorption lines, which
are consistent with a post-starburst (E+A) galaxy with an age of 650 Myr
and solar metallicity. The characteristics of iPTF16fnl make it an outlier on
both luminosity and decay timescales, as compared to other optically selected
TDEs. The discovery of such a faint optical event suggests a higher rate of
tidal disruptions, as low luminosity events may have gone unnoticed in previous
searches.Comment: 14 pages, 11 figures, accepted for publication in Ap
Scaling the Non-linear Impact Response of Flat and Curved Composite Panels
The application of scaling laws to thin flat and curved composite panels exhibiting nonlinear response when subjected to low-velocity transverse impact is investigated. Previous research has shown that the elastic impact response of structural configurations exhibiting geometrically linear response can be effectively scaled. In the present paper, a preliminary experimental study is presented to assess the applicability of the scaling laws to structural configurations exhibiting geometrically nonlinear deformations. The effect of damage on the scalability of the structural response characteristics, and the effect of scale on damage development are also investigated. Damage is evaluated using conventional methods including C-scan, specimen de-plying and visual inspection of the impacted panels. Coefficient of restitution and normalized contact duration are also used to assess the extent of damage. The results confirm the validity of the scaling parameters for elastic impacts. However, for the panels considered in the study, the extent and manifestation of damage do not scale according to the scaling laws. Furthermore, the results indicate that even though the damage does not scale, the overall panel response characteristics, as indicated by contact force profiles, do scale for some levels of damage
- …