12,331 research outputs found
High Prevalence of Tuberculosis among Adults with Fever Admitted at a Tertiary Hospital in North-western Tanzania
Tuberculosis is a leading cause of death in developing countries where HIV is endemic. This hospital based study was done to estimate the magnitude of pulmonary and extra-pulmonary tuberculosis and to determine predictors of tuberculosis among febrile adults admitted at Bugando Medical Centre (BMC), Mwanza, Tanzania. A total of 346 adults febrile patients admitted in medical wards were studied. Sputum for AFB microscopy and chest X-rays was used to diagnose tuberculosis. Clinical features were collected using standardized data collection tool. HIV testing and CD4 counts were determined. Data were analyzed using STATA version 11 software. Of 346 febrile adults patients 116 (33.5%) were diagnosed to have tuberculosis; of which 79 (68.1%) and 37 (31.9%) had pulmonary tuberculosis (PTB) and extra-pulmonary tuberculosis, respectively. Smear negative PTB were more common in HIV positive than in HIV negative patients (50% vs. 18.5%, p=0.007). Extra-pulmonary tuberculosis was more common in HIV positive patients than pulmonary tuberculosis (86.4% vs. 13.6%), p=0.0001). On multivariate logistic regression analysis the predictors of tuberculosis were; age above 35 years (OR =2.38, p=0.007), cardinal symptoms (OR=37, p<0.0001), pleural effusion (OR=24, p=0.0001), and HIV status (OR =3.2, p=0.0001). Of 79 patients with PTB, 48 (60.7%) were AFB smear positive and 31(39.3%) were AFB smear negative. HIV patients with smear negative tuberculosis had significantly lower CD4 count than HIV patients with smear positive tuberculosis (63.5 cells/μl versus 111.5 cells/μl) [Mann- Whitney test p=0.0431]]. No different in mortality was observed between patients with TB and those without TB admitted in BMC medical wards (28.5% vs. 23.0%, p= 0.1318). Tuberculosis is the commonest cause of fever among adults patients admitted at BMC and is predicted by age above 35 years, positive HIV status, cardinal PTB symptoms, and pleural effusion. Routinely TB screening is highly recommended among adults with fever, cough, night sweating and wasting in countries where HIV is endemic.\u
The Motion of a Body in Newtonian Theories
A theorem due to Bob Geroch and Pong Soo Jang ["Motion of a Body in General
Relativity." Journal of Mathematical Physics 16(1), (1975)] provides the sense
in which the geodesic principle has the status of a theorem in General
Relativity (GR). Here we show that a similar theorem holds in the context of
geometrized Newtonian gravitation (often called Newton-Cartan theory). It
follows that in Newtonian gravitation, as in GR, inertial motion can be derived
from other central principles of the theory.Comment: 12 pages, 1 figure. This is the version that appeared in JMP; it is
only slightly changed from the previous version, to reflect small issue
caught in proo
Solubilities of nitrogen, oxygen, and argon in distilled water
The solubilities of nitrogen, oxygen and argon in distilled water in the temperature range 2-27°C have been measured with an estimated accuracy approaching 0.1%. Both absolute and solubility ratio techniques were employed. Tabulations are presented and interrelationships among the results are noted
High Prevalence of Non-Typhoid Salmonella Bacteraemia Among Febrile HIV Adult Patients Admitted at a Tertiary Hospital, North-Western Tanzania.
Bacterial blood stream infections constitute a significant public-health problem and it is an important cause of morbidity and mortality in HIV infected patients. Little is known in developing countries regarding salmonella bacteraemia among HIV patients. The purpose of this study was to determine the bacterial pathogens causing blood stream infection among febrile adults attending in a tertiary hospital North-Western, Tanzania. A prospective cross-sectional study involving 346 consecutive, febrile adult patients admitted at Bugando Medical Centre was conducted. Demographic and other data were collected using standardized questionnaires. Blood culture was done followed by susceptibility testing using disc diffusion method. HIV testing was also performed as per Tanzania national algorithm and total white blood cell counts and CD4+ counts determined. Of 346 febrile adult patients 33 (9.5%) had blood stream infections. The common isolates were Salmonella spp 13(39.4%), Escherichia coli 8 (24.2%), Streptococcus pneumonia 5(15.2%), Staphylococcus aureus 4(12.1%), Citrobacter spp 1(3%), Streptococcus pyogenes 1(3%) and Klebsiella pneumonia 1(3%). A total of 156 (45.1%) patients were HIV infected; of whom 12/156 (7.6%) were infected by non-typhoid Salmonella spp compared to 1/190 (0.5%) of non-HIV infected patients (RRR 11.2, p=0.029) infected with Salmonella typhi. HIV infected patients with bacteraemia had significantly lower CD4+ count than those without bacteraemia (median 28 vs. 88 cells/ml, p=0.01). Patients with salmonella bacteraemia had significantly lower median of WBC than those with non-salmonella as well as those without bacteraemia (median, 3.6 vs. 17.5 vs. 9.8x109, p=0.0001). All Salmonella spp were sensitive to ceftriaxone and imipenem, while being 84%, 69.2%, 38% and 8% resistant to chloramphenicol, ampicillin, sulphamethaxazole/trimethoprim and ciprofloxacin respectively. Predictors of mortality were HIV infection (OR 2.3, p=0.006), Glasgow coma score of less than 15 (OR 3.4, p=0.0001) and night sweats (OR 2.4, p=0.014). Non-typhoid Salmonella spp that are highly resistant to common antibiotics are predominant cause of bacterial blood stream infection among HIV patients attending Bugando Medical Centre. Continuous surveillance and intervention strategies should be put in place to monitor and manage cases of bloodstream infections in HIV-positive patients in Mwanza, Tanzania
Parallax and Kinematics of PSR B0919+06 from VLBA Astrometry and Interstellar Scintillometry
Results are presented from a long-term astrometry program on PSR B0919+06
using the NRAO Very Long Baseline Array. With ten observations (seven epochs)
between 1994--2000, we measure a proper motion of 18.35 +/- 0.06 mas/yr in RA,
86.56 +/- 0.12 mas/yr in Dec, and a parallax of 0.83 +/- 0.13 mas (68%
confidence intervals). This yields a pulsar distance of 1.21 +/- 0.19 kpc,
making PSR B0919+06 the farthest pulsar for which a trigonometric parallax has
been obtained, and the implied pulsar transverse speed is 505 +/- 80 km/s.
Combining the distance estimate with interstellar scintillation data spanning
20 years, we infer the existence of a patchy or clumpy scattering screen along
the line of sight in addition to the distributed electron density predicted by
models for the Galaxy, and constrain the location of this scattering region to
within about 250 parsecs of the Sun. Comparison with the lines of sight towards
other pulsars in the same quadrant of the Galaxy permits refinement of our
knowledge of the local interstellar matter in this direction.Comment: 12 pages, includes 4 figures and 3 tables, uses AASTeX 5 (included);
ApJ submitte
Resistance to Gray Leaf Spot of Maize: Genetic Architecture and Mechanisms Elucidated through Nested Association Mapping and Near-Isogenic Line Analysis
Citation: Benson, J. M., Poland, J. A., Benson, B. M., Stromberg, E. L., & Nelson, R. J. (2015). Resistance to Gray Leaf Spot of Maize: Genetic Architecture and Mechanisms Elucidated through Nested Association Mapping and Near-Isogenic Line Analysis. Plos Genetics, 11(3), 23.
https://doi.org/10.1371/journal.pgen.1005045Gray leaf spot (GLS), caused by Cercospora zeae-maydis and Cercospora zeina, is one of the most important diseases of maize worldwide. The pathogen has a necrotrophic lifestyle and no major genes are known for GLS. Quantitative resistance, although poorly understood, is important for GLS management. We used genetic mapping to refine understanding of the genetic architecture of GLS resistance and to develop hypotheses regarding the mechanisms underlying quantitative disease resistance (QDR) loci. Nested association mapping (NAM) was used to identify 16 quantitative trait loci (QTL) for QDR to GLS, including seven novel QTL, each of which demonstrated allelic series with significant effects above and below the magnitude of the B73 reference allele. Alleles at three QTL, qGLS1.04, qGLS2.09, and qGLS4.05, conferred disease reductions of greater than 10%. Interactions between loci were detected for three pairs of loci, including an interaction between iqGLS4.05 and qGLS7.03. Near-isogenic lines (NILs) were developed to confirm and fine-map three of the 16 QTL, and to develop hypotheses regarding mechanisms of resistance. qGLS1.04 was fine-mapped from an interval of 27.0 Mb to two intervals of 6.5 Mb and 5.2 Mb, consistent with the hypothesis that multiple genes underlie highly significant QTL identified by NAM. qGLS2.09, which was also associated with maturity (days to anthesis) and with resistance to southern leaf blight, was narrowed to a 4-Mb interval. The distance between major leaf veins was strongly associated with resistance to GLS at qGLS4.05. NILs for qGLS1.04 were treated with the C. zeae-maydis toxin cercosporin to test the role of host-specific toxin in QDR. Cercosporin exposure increased expression of a putative flavin-monooxygenase (FMO) gene, a candidate detoxification-related gene underlying qGLS1.04. This integrated approach to confirming QTL and characterizing the potential underlying mechanisms advances the understanding of QDR and will facilitate the development of resistant varieties
Exploiting Cross Correlations and Joint Analyses
In this report, we present a wide variety of ways in which information from
multiple probes of dark energy may be combined to obtain additional information
not accessible when they are considered separately. Fundamentally, because all
major probes are affected by the underlying distribution of matter in the
regions studied, there exist covariances between them that can provide
information on cosmology. Combining multiple probes allows for more accurate
(less contaminated by systematics) and more precise (since there is
cosmological information encoded in cross-correlation statistics) measurements
of dark energy. The potential of cross-correlation methods is only beginning to
be realized. By bringing in information from other wavelengths, the
capabilities of the existing probes of dark energy can be enhanced and
systematic effects can be mitigated further. We present a mixture of work in
progress and suggestions for future scientific efforts. Given the scope of
future dark energy experiments, the greatest gains may only be realized with
more coordination and cooperation between multiple project teams; we recommend
that this interchange should begin sooner, rather than later, to maximize
scientific gains.Comment: Report from the "Dark Energy and CMB" working group for the American
Physical Society's Division of Particles and Fields long-term planning
exercise ("Snowmass"
In vitro activity of cefepime against extended spectrum β-lactamase- producing Escherichia coli and Klebsiella pneumoniae from clinical specimens at Bugando Medical Centre, Mwanza, Tanzania
There is an increase in isolation of extended spectrum beta-lactamase (ESBL) producing isolates from clinical samples worldwide. In developing countries the treatment option of ESBL producing isolates is limited. Recently fourth generation cephalosporins have been introduced for use in Tanzania. This study was done to determine in vitro activity of cefepime against ESBL producing clinical isolates. Disc diffusion testing was performed to 235 ESBL producing isolates; of which 73 (31%) were Escherichia coli and 162 (69%) Klebsiella pneumoniae. The sensitivity rate of E. coli and K. pneumoniae to cefepime were 15.1% and 4.3%, respectively (P=0.012); intermediate sensitivity rate was observed in 13.7% for E. coli and 19.8% for K. pneumoniae. The mean zones of inhibition diameter among sensitive isolates were 24.9mm and 20.0mm for E. coli and K. pneumonia, respectively (P=0.0085). Cefepime is less active against ESBL producing organisms; hence the use of this drug should be guided using local resistance profile
The Role of Legal Services in the Antipoverty Program
Large-scale adaptive radiations might explain the runaway success of a minority of extant vertebrate clades. This hypothesis predicts, among other things, rapid rates of morphological evolution during the early history of major groups, as lineages invade disparate ecological niches. However, few studies of adaptive radiation have included deep time data, so the links between extant diversity and major extinct radiations are unclear. The intensively studied Mesozoic dinosaur record provides a model system for such investigation, representing an ecologically diverse group that dominated terrestrial ecosystems for 170 million years. Furthermore, with 10,000 species, extant dinosaurs (birds) are the most speciose living tetrapod clade. We assembled composite trees of 614-622 Mesozoic dinosaurs/birds, and a comprehensive body mass dataset using the scaling relationship of limb bone robustness. Maximum-likelihood modelling and the node height test reveal rapid evolutionary rates and a predominance of rapid shifts among size classes in early (Triassic) dinosaurs. This indicates an early burst niche-filling pattern and contrasts with previous studies that favoured gradualistic rates. Subsequently, rates declined in most lineages, which rarely exploited new ecological niches. However, feathered maniraptoran dinosaurs (including Mesozoic birds) sustained rapid evolution from at least the Middle Jurassic, suggesting that these taxa evaded the effects of niche saturation. This indicates that a long evolutionary history of continuing ecological innovation paved the way for a second great radiation of dinosaurs, in birds. We therefore demonstrate links between the predominantly extinct deep time adaptive radiation of non-avian dinosaurs and the phenomenal diversification of birds, via continuing rapid rates of evolution along the phylogenetic stem lineage. This raises the possibility that the uneven distribution of biodiversity results not just from large-scale extrapolation of the process of adaptive radiation in a few extant clades, but also from the maintenance of evolvability on vast time scales across the history of life, in key lineages
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