201 research outputs found
Opportunities for strengthening provider-initiated testing and counselling for HIV in Namibia
This short report identifies enablers and barriers to the uptake of provider-initiated testing and counselling for HIV (PITC) in Namibia and identifies key opportunities for strengthening this vital aspect of the national HIV response. We explored this through facility mapping, register reviews and qualitative methods including focus group discussions and in-depth interviews. Four health facilities (clinics and hospitals) in two regions were included in the study. We identified that PITC in Namibia was largely delivered by lay counsellors operating in designated rapid testing rooms located in health facilities and found a large number of missed opportunities for HIV testing through this model. Nurses did not see it as an integral part of their role, were not aware of HIV testing and counselling policy, felt inadequately trained and supported, and experienced staffing shortages. Institutional issues also acted as barriers to nurses performing or initiating discussions about PITC. Wider dissemination and implementation of policy, increasing privacy of consultation spaces and community sensitisation are simple measures that represent opportunities for strengthening this response and ensuring that symptomatic individuals who are unaware of their HIV status do not fall through the net
Atrazine Transport Within a Coastal Zone in Southeastern Puerto Rico: a Sensitivity Analysis of an Agricultural Field Model and Riparian Zone Management Model
Agrichemical runoff from farmland may adversely impact coastal water quality. Two models, the Agricultural Policy/Environmental eXtender (APEX) and the Riparian Ecosystem Management Model (REMM), were used to evaluate the movement of the herbicide atrazine to the Jobos Bay National Estuarine Research Reserve from adjacent fields. The reserve is located on Puerto Rico’s southeast coast. Edge-of-field atrazine outputs simulated with the APEX were routed through a grass-forest buffer using the REMM. Atrazine DT50 (half-life) values measured in both field and buffer soils indicated that accelerated degradation conditions had developed in the field soil due to repeated atrazine application. APEX simulations examined both the measured field and buffer soil atrazine DT50 and the model’s default value. The use of the measured field soil atrazine degradation rate in the APEX resulted in 33 % lower atrazine transport from the field. REMMsimulations indicated that the buffer system had the potential to reduce dissolved atrazine transport in surface runoff by 77%during non-tropical stormevents by increasing infiltration, slowing transport, and increasing time for pesticide degradation. During a large runoff event due to a tropical stormthat occurred close to the time of an atrazine application, the REMM simulated only a 37 % reduction in atrazine transport. The results indicate that large storm events soon after herbicide application likely dominate herbicide transport to coastal waters in the region. These results agree with water quality measurements in the reserve. This study demonstrated the sensitivity of these models to variations in DT50 values in evaluating atrazine fate and transport in the region and emphasizes that the use of measured DT50 values can improve model accuracy
Ethnic Differences in Bladder Cancer Survival
ObjectiveTo examine trends in bladder cancer survival among whites, blacks, Hispanics, and Asian/Pacific Islanders in the United States over a 30-year period. Racial disparities in bladder cancer outcomes have been documented with poorer survival observed among blacks. Bladder cancer outcomes in other ethnic minority groups are less well described.MethodsFrom the Surveillance, Epidemiology and End Results cancer registry data, we identified patients diagnosed with transitional cell carcinoma of the bladder between 1975 and 2005. This cohort included 163,973 white, 7731 black, 7364 Hispanic, and 5934 Asian/Pacific Islander patients. We assessed the relationship between ethnicity and patient characteristics. Disease-specific 5-year survival was estimated for each ethnic group and for subgroups of stage and grade.ResultsBlacks presented with higher-stage disease than whites, Hispanics, and Asian/Pacific Islanders, although a trend toward earlier-stage presentation was observed in all groups over time. Five-year disease-specific survival was consistently worse for blacks than for other ethnic groups, even when stratified by stage and grade. Five-year disease-specific survival was 82.8% in whites compared with 70.2% in blacks, 80.7% in Hispanics, and 81.9% in Asian/Pacific Islanders. There was a persistent disease-specific survival disadvantage in black patients over time that was not seen in the other ethnic groups.ConclusionEthnic disparities in bladder cancer survival persist between whites and blacks, whereas survival in other ethnic minority groups appears similar to that of whites. Further study of access to care, quality of care, and treatment decision making among black patients is needed to better understand these disparities
NICMOS Imaging of the HR 4796A Circumstellar Disk
We report the first near infrared (NIR) imaging of a circumstellar annular
disk around the young (~8 Myr), Vega-like star, HR 4796A. NICMOS coronagraph
observations at 1.1 and 1.6 microns reveal a ring-like symmetrical structure
peaking in reflected intensity 1.05 arcsec +/- 0.02 arcsec (~ 70 AU) from the
central A0V star. The ring geometry, with an inclination of 73.1 deg +/- 1.2
deg and a major axis PA of 26.8 deg +/- 0.6 deg, is in good agreement with
recent 12.5 and 20.8 micron observations of a truncated disk (Koerner, et al.
1998). The ring is resolved with a characteristic width of less than 0.26
arcsec (17 AU) and appears abruptly truncated at both the inner and outer
edges. The region of the disk-plane inward of ~60 AU appears to be relatively
free of scattering material. The integrated flux density of the part of the
disk that is visible (greater than 0.65 arcsec from the star) is found to be
7.5 +/- 0.5 mJy and 7.4 +/- 1.2 mJy at 1.1 and 1.6 microns, respectively.
Correcting for the unseen area of the ring yields total flux densities of 12.8
+/- 1.0 mJy and 12.5 +/- 2.0 mJy, respectively (Vega magnitudes = 12.92 /+-
0.08 and 12.35 +/-0.18). The NIR luminosity ratio is evaluated from these
results and ground-based photometry of the star. At these wavelengths
Ldisk(lambda)/L*(lambda) = 1.4 +/- 0.2E-3 and 2.4 +/- 0.5E-3, giving reasonable
agreement between the stellar flux scattered in the NIR and that which is
absorbed in the visible and re-radiated in the thermal infrared. The somewhat
red reflectance of the disk at these wavelengths implies mean particle sizes in
excess of several microns, larger than typical interstellar grains. The
confinement of material to a relatively narrow annular zone implies dynamical
constraints on the disk particles by one or more as yet unseen bodies.Comment: 14 pages, 1 figure for associated gif file see:
http://nicmosis.as.arizona.edu:8000/AAS99/FIGURE1_HR4796A_ApJL.gif . Accepted
13 January 1999, Astrophyical Journal Letter
HST/NICMOS detection of HR 8799 b in 1998
Three planets have been directly imaged around the young star HR 8799. The
planets are 5-13 Mjup and orbit the star at projected separations of 24-68 AU.
While the initial detection occurred in 2007, two of the planets were recovered
in a re-analysis of data obtained in 2004. Here we present a detection of the
furthest planet of that system, HR 8799 b, in archival HST/NICMOS data from
1998. The detection was made using the locally-optimized combination of images
algorithm to construct, from a large set of HST/NICMOS images of different
stars taken from the archive, an optimized reference point-spread function
image used to subtract the light of the primary star from the images of HR
8799. This new approach improves the sensitivity to planets at small
separations by a factor of ~10 compared to traditional roll deconvolution. The
new detection provides an astrometry point 10 years before the most recent
observations, and is consistent with a Keplerian circular orbit with a~70 AU
and low orbital inclination. The new photometry point, in the F160W filter, is
in good agreement with an atmosphere model with intermediate clouds and
vertical stratification, and thus suggests the presence of significant water
absorption in the planet's atmosphere. The success of the new approach used
here highlights a path for the search and characterization of exoplanets with
future space telescopes, such as the James Webb Space Telescope or a
Terrestrial Planet Finder.Comment: ApJL, in pres
Recommended from our members
Evaluation of the Rapid Scale-up of Collaborative TB/HIV Activities in TB Facilities in Rwanda, 2005-2009
In 2005, Rwanda drafted a national TB/HIV policy and began scaling-up collaborative TB/HIV activities. Prior to the scale-up, we evaluated existing TB/HIV practices, possible barriers to policy and programmatic implementation, and patient treatment outcomes. We then used our evaluation data as a baseline for evaluating the national scale-up of collaborative TB/HIV activities from 2005 through 2009. Our baseline evaluation included a cross-sectional evaluation of 23/161 TB clinics. We conducted structured interviews with patients and clinic staff and reviewed TB registers and patient records to assess HIV testing practices, provision of HIV care and treatment for people with TB that tested positive for HIV, and patients' TB treatment outcomes. Following our baseline evaluation, we used nationally representative TB/HIV surveillance data to monitor the scale-up of collaborative TB/HIV activities Of 207 patients interviewed, 76% were offered HIV testing, 99% accepted, and 49% reported positive test results. Of 40 staff interviewed, 68% reported offering HIV testing to >50% of patients. From 2005-2009, scaled-up TB/HIV activities resulted in increased HIV testing of patients with TB (69% to 97%) and provision of cotrimoxazole (15% to 92%) and antiretroviral therapy (13% to 49%) for patients with TB disease and HIV infection (TB/HIV). The risk of death among patients with TB/HIV relative to patients with TB not infected with HIV declined from 2005 (RR = 6.1, 95%CI 2.6, 14.0) to 2007 (RR = 1.8, 95%CI 1.68, 1.94). Our baseline evaluation highlighted that staff and patients were receptive to HIV testing. However, expanded access to testing, care, and treatment was needed based on the proportion of patients with TB having unknown HIV status and the high rate of HIV infection and poorer TB treatment outcomes for patients with TB/HIV. Following our evaluation, scale-up of TB/HIV services resulted in almost all patients with TB knowing their HIV status. Scale-up also resulted in dramatic increases in the uptake of lifesaving HIV care and treatment coinciding with a decline in the risk of death among patients with TB/HIV
The Directly Imaged Planet around the Young Solar Analog 1RXS J160929.1-210524: Confirmation of Common Proper Motion, Temperature and Mass
Giant planets are usually thought to form within a few tens of AU of their
host stars, and hence it came as a surprise when we found what appeared to be a
planetary mass (~0.008 Msun) companion around the 5 Myr-old solar mass star
1RXS J160929.1-210524 in the Upper Scorpius association. At the time, we took
the object's membership in Upper Scorpius -- established from near-infrared, H-
and K-band spectroscopy -- and its proximity (2.2", or 330 AU) to the primary
as strong evidence for companionship, but could not verify their common proper
motion. Here, we present follow-up astrometric measurements that confirm that
the companion is indeed co-moving with the primary star, which we interpret as
evidence that it is a truly bound planetary mass companion. We also present new
J-band spectroscopy and 3.0-3.8 microns photometry of the companion. Based on a
comparison with model spectra, these new measurements are consistent with the
previous estimate of the companion effective temperature of 1800+/-200 K. We
present a new estimate of the companion mass based on evolution models and the
calculated bolometric luminosity of the companion; we obtain a value of 0.008
(-0.002/+0.003) Msun, again consistent with our previous result. Finally, we
present angular differential imaging observations of the system allowing us to
rule out additional planets in the system more massive than 1, 2 and 8 Mjup at
projected separations larger than 3" (~440 AU), 0.7" (~100 AU) and 0.35" (~50
AU), respectively. This companion is the least massive known to date at such a
large orbital distance; it shows that objects in the planetary mass range exist
at orbital separations of several hundred AU, posing a serious challenge for
current formation models.Comment: Published in ApJ, 8 pages in emulateapj forma
Enhancement of the Spitzer Infrared Array Camera Distortion Correction for Parallax Measurements
The Spitzer Space Telescope Infrared Array (IRAC) offers a rare opportunity to measure distances and determine physical properties of the faintest and coldest brown dwarfs. The current distortion correction is a 3rd order polynomial represented by TAN-SIP parameters within the headers. The current correction, good to 100 mas, was derived from deep imaging, using marginally resolved galaxies in some cases, and has remained stable throughout both the cryogenic and warm mission. Using recent Spitzer calibration observations mapped to HST/ACS calibration observations of 47 Tuc with an absolute accuracy good to 1 mas, we are working towards a possible 5th order polynomial correction that theoretically could allow measurements to within 20 mas. Extensive testing, using observations of 47 Tuc, NGC 6791 and NGC 2264, are underway, after which the new parameters will be used to update all the 3.6 and 4.5um data taken within warm and cryogenic missions. We anticipate if achievable, this new accuracy could be combined with other ongoing enhancements (Ingalls et al, 9143-52) that will permit measurements of parallaxes out to about 50 pc, increasing the volume surveyed by a factor of 100, and enabling new capabilities such as luminosity measurements of the population of young brown dwarfs in the beta Pictoris moving group
The Rwanda Field Epidemiology and Laboratory Training Program: training skilled disease detectives
Rwanda still suffers from communicable diseases which frequently lead to epidemics. In addition to other health workforce needs, Rwanda also lacks a public health workforce that can operate multi-disease surveillance and response systems at the national and sub-national levels.In 2009 and 2010 the Rwanda Ministry of Health and its partners from the Government of Rwanda (GOR) as well as the United States (US) Centers for Disease Control and Prevention, the African Field Epidemiology Network, and other partners embarked on a series of activities to develop a public health workforce that would be trained to operate disease surveillance and response systems at the national and district levels. The Rwanda Field Epidemiology and Laboratory Training Program (RFELTP) is a 2-year public health leadership development training program that provides applied epidemiology and public health laboratory training while the trainees provide public health service to the Ministry of Health. RFELTP is hosted at the National University of Rwanda School of Public Health for the didactic training. RFELTP is funded by GOR, the US Presidents Emergency Plan for AIDS Relief and the World Bank; it is managed by a multi-sectoral steering committee headed by the Minister of Health. The first RFELTP cohort has 15 residents who were recruited from key health programs in GOR. Over the first year of implementation, these 15 residents have conducted a variety of field investigations and responded to several outbreaks. RFELTP has also trained 145 frontline health workers through its two-week applied short courses. In the future, RFELTP plans to develop a veterinary track to address public health issues at the animal-human interface
Task Shifting for Scale-up of HIV Care: Evaluation of Nurse-Centered Antiretroviral Treatment at Rural Health Centers in Rwanda
Fabienne Shumbusho and colleagues evaluate a task-shifting model of nurse-centered antiretroviral treatment prescribing in rural primary health centers in Rwanda and find that nurses can effectively and safely prescribe ART when given adequate training, mentoring, and support
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