1,516 research outputs found
Impact of Human Immunodeficiency Virus Infection on the Outcome of Treatment and Survival of Tuberculosis Patients in Mwanza, Tanzania.
Little is known about the outcome of tuberculosis (TB) treatment and subsequent survival of human immunodeficiency virus (HIV) infected patients treated under routine programme conditions in a developing country. We followed a cohort of HIV-positive and HIV-negative tuberculosis patients during therapy and assessed their vital and tuberculosis status 3 years after completion of treatment in Mwanza, Tanzania. Newly diagnosed and relapse tuberculosis cases consecutively registered over a 6-month period were enrolled into an epidemiological study of TB/HIV. Treatment outcome was based on information in tuberculosis treatment registers. Patients surviving treatment were assessed 3 years later by personal interview. Cause of death was determined by verbal autopsy. Of 561 patients enrolled into the study, 505 patients alive at completion of treatment were eligible for assessment at 3 years. Except for mortality, HIV infection was not statistically associated with differing treatment outcomes. At time of follow-up, the overall mortality was 19% and was associated with HIV infection (hazard ratio [hr] 3.7, 95% confidence interval [CI] 2.6-5.2) and age 35 years and over (hr 1.5, 95% CI 1.02-2.1), but not with type of tuberculosis, gender, or initial drug resistance. By life table analysis, probability of survival at 4 years was 35% for HIV-positive patients compared to 90% for HIV-negative patients. Although no relapse cases were diagnosed, verbal autopsy suggested equivalent low rates of relapse in both groups. These results demonstrate the effectiveness of the current approach to the treatment of tuberculosis patients regardless of HIV status. However, HIV-related mortality remains high both during and following completion of treatment, and further studies are needed to determine if this mortality might be reduced by simple interventions which are feasible in developing countries.\u
Mechanics of cooling liquids by forced evaporation in bubbles
Injecting a non-dissolvable gas into a saturated liquid results in
sub-cooling of the liquid due to forced evaporation into the bubble. Previous
studies assumed the rate of evaporation of liquid into the bubble to be
independent of the degree of sub-cooling. In our study we quantify the bubble
growth by direct observation using high speed imaging and prove that this
hypothesis is not true. A phenomenological model of the bubble growth as a
function of the degree of sub-cooling is developed and we find excellent
agreement between the measurements and theory. This bubble cooling process is
employed in cooling a liquid. By identification of all heat flows, we can well
describe the cool down curve using bubble cooling. Bubble cooling provides an
alternative cooling method for liquids without the use of complicated cooling
techniques
The Merging System Am 2049-691
Spectroscopic and photometric observations of the peculiar object AM 2049-691
are presented here. Its systemic velocity is V(GSR) = (10956 +-30) km/s, and
the derived distance (H(0) = 75 km/s/Mpc) results 146 Mpc. A bridge is observed
between two very distinct nuclei whose separation is about 10 kpc, as well as
two tails that emerge from the extremes SW and NE of the main body and extend
up to 41 and 58 kpc respectively. The spectral characteristics of the all
observed zones are typical of H II regions of low excitation. The internal
reddening is quit high, particularly in the NE nucleus. All the derived
equivalent widths of the H(alpha)+[N II] lines indicate enhanced star formation
compared with isolated galaxies, specially in the NE nucleus; the equivalent
width corresponding to the integrated spectrum reflects starburst activity in
the whole object, and is compatible with a merger of two disk galaxies. All the
observed characteristics of AM 2049-691 indicate it is a merger, where a
overabundance of nitrogen is detected in one of the nuclei, which has the most
evolved population and would be the most massive one. The detected total IR
emission is not very high. The integrated total color B - V corresponds to a
Sc-Scd galaxy and its average integrated population is about F7 type.
Indicative B - V colors of the nuclei, corrected for internal absorption, are
in agreement with the spectroscopic results. The central radial velocity
dispersions at the nuclei suggest that the most massive galaxy would be the
progenitor of the SW component. The observed radial velocity curve shows the
presence of two subsystems, each one associated with a different nucleus.Comment: 5 pages, 4 figure
Investigation of amphibian mortality events in wildlife reveals an on-going ranavirus epidemic in the North of the Netherlands
In the four years following the first detection of ranavirus (genus Ranavirus, family Iridoviridae) infection in Dutch wildlife in 2010, amphibian mortality events were investigated nationwide to detect, characterize and map ranaviruses in amphibians over time, and to establish the affected host species and the clinico-pathological presentation of the disease in these hosts. The ultimate goal was to obtain more insight into ranavirus disease emergence and ecological risk. In total 155 dead amphibians from 52 sites were submitted between 2011 and 2014, and examined using histopathology, immunohistochemistry, virus isolation and molecular genetic characterization. Ranavirus-associated amphibian mortality events occurred at 18 sites (35%), initially only in proximity of the 2010 index site. Specimens belonging to approximately half of the native amphibian species were infected, including the threatened Pelobates fuscus (spadefoot toad). Clustered massive outbreaks involving dead adult specimens and ranavirus genomic identity indicated that one common midwife toad virus (CMTV)-like ranavirus strain is emerging in provinces in the north of the Netherlands. Modelling based on the spatiotemporal pattern of spread showed a high probability that this emerging virus will continue to be detected at new sites (the discrete reproductive power of this outbreak is 0.35). Phylogenetically distinct CMTV-like ranaviruses were found in the south of the Netherlands more recently. In addition to showing that CMTV-like ranaviruses threaten wild amphibian populations not only in Spain but also in the Netherlands, the current spread and risk of establishment reiterate that understanding the underlying causes of CMTV-like ranavirus emergence requires international attention
The APPLe Study: A Randomized, Community-Based, Placebo-Controlled Trial of Azithromycin for the Prevention of Preterm Birth, with Meta-Analysis
In a randomized trial in Malawi of azithromycin versus placebo in over 2,000 pregnant women, Jim Neilson and colleagues show no benefit of azithromycin for a number of outcomes including preterm birth and prenatal death
Radio-Luminous Southern Seyfert Galaxies. I. Radio Images and Selected Optical/Near-Infrared Spectroscopy
This is the first of two papers in which a study is made of a sample of 12
southern radio-luminous Seyfert galaxies. Our aim is to investigate possible
correlations between radio morphology and nuclear/circumnuclear emission-line
properties. In this paper we present radio images at 13, 6, and 3 cm taken with
the Australia Telescope Compact Array (ATCA), global far-infrared (FIR)
properties for the whole sample, and optical and near-infrared (NIR)
spectroscopy of an interesting subset. We find a mixture of radio morphologies,
including linear, diffuse and compact sources. When the FIR colors of the
galaxies are considered there is an indication that the compact radio sources
have warmer FIR colors than the diffuse sources, whereas the linear sources
span a wide range of FIR colors. There is a wide variation in radio
spectral-indices, suggesting that free-free absorption is significant in some
systems, particularly IRAS 11249-2859, NGC 4507, and NGC 7213. Detailed
emission-line studies are presented of 4 galaxies IC 3639, NGC 5135, NGC 3393 &
IRAS 11249-2859. In IC 3639 we present evidence of vigorous, compact star
formation enclosed by very extended [OI]6300 emission, suggestive of the
boundary between a diffuse outflow and the surrounding ISM. In another galaxy,
IC 5063, we see evidence for the possible interaction of a highly collimated
outflow and the surrounding rotating inner disk. Of the 5 galaxies which show
compact radio emission, 4 have radio/FIR flux ratios consistent with an
energetically dominant AGN, whereas IC 4995 exhibits evidence for a very
compact starburst.Comment: 42 pages, including 7 tables, latex, 19 jpeg figures, Accepted to
ApJ. Replacement updates coordintes of galaxies in Table
Sampling Local Fungal Diversity in an Undergraduate Laboratory using DNA Barcoding
Traditional methods for fungal species identification require diagnostic morphological characters and are often limited by the availability of fresh fruiting bodies and local identification resources. DNA barcoding offers an additional method of species identification and is rapidly developing as a critical tool in fungal taxonomy. As an exercise in an undergraduate biology course, we identified 9 specimens collected from the Hendrix College campus in Conway, Arkansas, USA to the genus or species level using morphology. We report that DNA barcoding targeting the internal transcribed spacer (ITS) region supported several of our taxonomic determinations and we were able to contribute 5 ITS sequences to GenBank that were supported by vouchered collection information. We suggest that small-scale barcoding projects are possible and that they have value for documenting fungal diversity
Cross validation of bi-modal health-related stress assessment
This study explores the feasibility of objective and ubiquitous stress assessment. 25 post-traumatic stress disorder patients participated in a controlled storytelling (ST) study and an ecologically valid reliving (RL) study. The two studies were meant to represent an early and a late therapy session, and each consisted of a "happy" and a "stress triggering" part. Two instruments were chosen to assess the stress level of the patients at various point in time during therapy: (i) speech, used as an objective and ubiquitous stress indicator and (ii) the subjective unit of distress (SUD), a clinically validated Likert scale. In total, 13 statistical parameters were derived from each of five speech features: amplitude, zero-crossings, power, high-frequency power, and pitch. To model the emotional state of the patients, 28 parameters were selected from this set by means of a linear regression model and, subsequently, compressed into 11 principal components. The SUD and speech model were cross-validated, using 3 machine learning algorithms. Between 90% (2 SUD levels) and 39% (10 SUD levels) correct classification was achieved. The two sessions could be discriminated in 89% (for ST) and 77% (for RL) of the cases. This report fills a gap between laboratory and clinical studies, and its results emphasize the usefulness of Computer Aided Diagnostics (CAD) for mental health care
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