6,402 research outputs found
The SKA view of the Neutral Interstellar Medium in Galaxies
Two major questions in galaxy evolution are how star-formation on small
scales leads to global scaling laws and how galaxies acquire sufficient gas to
sustain their star formation rates. HI observations with high angular
resolution and with sensitivity to very low column densities are some of the
important observational ingredients that are currently still missing. Answers
to these questions are necessary for a correct interpretation of observations
of galaxy evolution in the high-redshift universe and will provide crucial
input for the sub-grid physics in hydrodynamical simulations of galaxy
evolutions. In this chapter we discuss the progress that will be made with the
SKA using targeted observations of nearby individual disk and dwarf galaxies.Comment: 22 pages, 4 figures, to appear as part of 'Neutral Hydrogen' in
Proceedings 'Advancing Astrophysics with the SKA (AASKA14)', PoS(AASKA14)12
Molecular typing and antibiotic sysceptibility patterns of enteropathogenic and shigatoxin producing Escherichia coli isolated from food handlers in three areas of Kenya
Objectives: To determine the aetiology, epidemiology and sanitary factors of carriage of enteropathogenic Escherichia coli (EPEC) and Shiga-toxin producing E. coli (STEC) in food-handlers working in tourist hotels in three popular tourist destinations in Kenya.Design: Cross sectional laboratory based study.Setting: Three tourist destinations of Nairobi, Malindi and Diani in Kenya.Subjects: Food handlers who were working in hotels frequented by tourists in the three study sites.Results: Overall, during the period of April 2003 to May 2004, a total of 1399 food handlers stool samples were collected and analysed. EPEC expressing the eaeA gene and STEC expressing the stx2 gene were detected in 11/1399 (0.8%) and 2/1399 (0.1%) of the study subjects respectively. The mean age of the subjects from whom EPEC and STEC were isolated was similar (32.6 years) to those from whom no EPEC and STEC were isolated (32.5 years). Prior use of antibiotics, water source and toilet types were not significantly associated with the isolation of EPEC and STEC (p>0.05). There were 11 resistance patterns with six isolates (6/13, 46.2%) showing multidrug resistance. High prevalence of resistance was observed to co-trimoxazole (55.6%), chloramphenicol (33.3%), ampicillin (22.2%) and tetracycline (22.2%). High concentrations of antibiotics were required to achieve MlC90 for tetracycline, (>64 mg ml-1) and ampicillin (>256 mg ml-1). Cluster analysis of the Pulse Field Gel Electrophoresis profiles revealed that the EPEC and STEC isolates belonged to two main genotypes with 11 distinct DNA fragment profiles.Conclusion: This is the first report in Africa on the isolation of STEC from food handlers working in tourist hotels. These food handlers who carry the STEC and EPEC could potentially infect tourists and other people through food or water contamination in the hotel settings and thus our findings are of great public health importance
Quantitative Changes In Antibodies Against Onchocercal Native Antigens Two Months Postivermectin Treatment Of Onchocerciasis Patients
Serum antibodies to Onchocerca volvulus native sodium duodecylsulphate slat extracted antigens and epitopes recognized by three monoclonal antibodies designated Cam8, Cam22, and Cam28 were measured using indirect (sandwich) and competitive enzyme-linked immunosorbent assay (ELISA). Paired serum samples (n=32) were obtained before and two months post-ivermectin treatment. Those with increases of ten percent and above (≥10%) were 16 (50%) for IgG, 13 (40.7%) for both IgG1 and IgG4. Nine (28.2%) for IgM, eight (25%) for IgG3, IgA with four (12.5%) was the least, while IgG2 was not assayed due to cross-reaction. The higher increases in IgG, IgG1 and IgG4 antibodies in
females (n=16) than males (n=16) were significant by T-test of unpaired data (
Learning Optimal Deep Projection of F-FDG PET Imaging for Early Differential Diagnosis of Parkinsonian Syndromes
Several diseases of parkinsonian syndromes present similar symptoms at early
stage and no objective widely used diagnostic methods have been approved until
now. Positron emission tomography (PET) with F-FDG was shown to be able
to assess early neuronal dysfunction of synucleinopathies and tauopathies.
Tensor factorization (TF) based approaches have been applied to identify
characteristic metabolic patterns for differential diagnosis. However, these
conventional dimension-reduction strategies assume linear or multi-linear
relationships inside data, and are therefore insufficient to distinguish
nonlinear metabolic differences between various parkinsonian syndromes. In this
paper, we propose a Deep Projection Neural Network (DPNN) to identify
characteristic metabolic pattern for early differential diagnosis of
parkinsonian syndromes. We draw our inspiration from the existing TF methods.
The network consists of a (i) compression part: which uses a deep network to
learn optimal 2D projections of 3D scans, and a (ii) classification part: which
maps the 2D projections to labels. The compression part can be pre-trained
using surplus unlabelled datasets. Also, as the classification part operates on
these 2D projections, it can be trained end-to-end effectively with limited
labelled data, in contrast to 3D approaches. We show that DPNN is more
effective in comparison to existing state-of-the-art and plausible baselines.Comment: 8 pages, 3 figures, conference, MICCAI DLMIA, 201
Effect of single dose magnesium on arrhythmias in patients undergoing coronary artery bypass surgery
OBJECTIVE: To evaluate the safety and role of prophylactic administration of magnesium in preventing arrhythmias. METHOD: This double blind randomized placebo controlled clinical trial was conducted at Aga Khan University Hospital on coronary artery bypass surgery patients. All patients were connected to holter monitor before induction of anaesthesia and this monitoring continued for 24 hours. Study drug containing either 2-grams of magnesium or normal saline was given after intubation. Levels of serum magnesium was checked preoperatively and then in ICU at 0, 6, 12, and 24 hours. Independent t-test and chi square test were used for analysis. Statistical significance was defined as p-value \u3c 0.05. RESULTS: A total of 104 patients consented to participate in the study, 53 patients were randomly allocated in magnesium (Mg) group and 51 in placebo group. Two (3.77%) patients in magnesium group and five patients (9.8%) in placebo group developed atrial fibrillation. Incidence of ventricular and supraventricular tachycardia was also slightly higher in placebo. Mg level after arrival in CICU (Cardiac Intensive Care Unit) showed mean of 2.1 in magnesium group and 1.6 in placebo group (p = 0.6). CONCLUSION: Low magnesium levels were noticed in the placebo group after cardiopulmonary bypass and although prophylactic administration of magnesium sulphate was relatively safe but significant benefit on prevention of arrhythmias could not be attained
Experimental study of Pomeron
A Pomeron phenomenon remains a mystery. A short review of the experimental
situation in diffractive physics and an account of some spectacular
manifestations of the Pomeron are given.Comment: 17 pages, 7 Figs, LATEX. Talk given at the conference "From the
smallest to largest distances", ITEP, Moscow, 24-26 May 2001. Changes: Fig.2
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Evolution of Mycobacterium ulcerans and other mycolactone-producing mycobacteria from a common Mycobacterium marinum progenitor
It had been assumed that production of the cytotoxic polyketide mycolactone was strictly associated with Mycobacterium ulcerans, the causative agent of Buruli ulcer. However, a recent study has uncovered a broader distribution of mycolactone-producing mycobacteria (MPM) that includes mycobacteria cultured from diseased fish and frogs in the United States and from diseased fish in the Red and Mediterranean Seas. All of these mycobacteria contain versions of the M. ulcerans pMUM plasmid, produce mycolactones, and show a high degree of genetic relatedness to both M. ulcerans and Mycobacterium marinum. Here, we show by multiple genetic methods, including multilocus sequence analysis and DNA-DNA hybridization, that all MPM have evolved from a common M. marinum progenitor to form a genetically cohesive group among a more diverse assemblage of M. marinum strains. Like M. ulcerans, the fish and frog MPM show multiple copies of the insertion sequence IS2404. Comparisons of pMUM and chromosomal gene sequences demonstrate that plasmid acquisition and the subsequent ability to produce mycolactone were probably the key drivers of speciation. Ongoing evolution among MPM has since produced at least two genetically distinct ecotypes that can be broadly divided into those typically causing disease in ectotherms (but also having a high zoonotic potential) and those causing disease in endotherms, such as humans
Exploring Neutral Hydrogen and Galaxy Evolution with the SKA
One of the key science drivers for the development of the SKA is to observe
the neutral hydrogen, HI, in galaxies as a means to probe galaxy evolution
across a range of environments over cosmic time. Over the past decade, much
progress has been made in theoretical simulations and observations of HI in
galaxies. However, recent HI surveys on both single dish radio telescopes and
interferometers, while providing detailed information on global HI properties,
the dark matter distribution in galaxies, as well as insight into the
relationship between star formation and the interstellar medium, have been
limited to the local universe. Ongoing and upcoming HI surveys on SKA
pathfinder instruments will extend these measurements beyond the local universe
to intermediate redshifts with long observing programmes. We present here an
overview of the HI science which will be possible with the increased
capabilities of the SKA and which will build upon the expected increase in
knowledge of HI in and around galaxies obtained with the SKA pathfinder
surveys. With the SKA1 the greatest improvement over our current measurements
is the capability to image galaxies at reasonable linear resolution and good
column density sensitivity to much higher redshifts (0.2 < z < 1.7). So one
will not only be able to increase the number of detections to study the
evolution of the HI mass function, but also have the sensitivity and resolution
to study inflows and outflows to and from galaxies and the kinematics of the
gas within and around galaxies as a function of environment and cosmic time out
to previously unexplored depths. The increased sensitivity of SKA2 will allow
us to image Milky Way-size galaxies out to redshifts of z=1 and will provide
the data required for a comprehensive picture of the HI content of galaxies
back to z~2 when the cosmic star formation rate density was at its peak.Comment: 25 pages, 5 figures, 3 tables. Contribution to the conference
'Advancing Astrophysics with the Square Kilometre Array', June 8-13, 2014,
Giardini Naxos, Ital
Evaluation of oxidative stress using exhaled breath 8-isoprostane levels on chronic kidney disease
Background: There have been limited numbers of studies on patients with chronic kidney disease (CKD) to determine oxidative stress in exhaled breath condensate (EBC). Those two studies have been carried out on hemodialysis patients, and hydrogen peroxide and nitric oxide have been studied in order to show oxidative stress on EBC.Aims: We investigated oxidative stress in EBC evaluating 8.isoprostane levels on different stages of CKD.Materials and Methods: A total of 81 patients with 2-4 CKD stages have been evaluated prospectively. The patients have been categorized into three groups according to their CKD stages. For biochemical analysis, blood and breathing air samples were taken. 8.-isoprostane has been measured using immunoassay method as the indicator of oxidative stress in EBC.Results: 8-isoprostane values were 8.19 ± 4.56, 13.89 ± 8.70, and 14.20 ± 10.68 pg/min group 1, 2, and 3, respectively; and the EBC 8-isoprostane levels increased significantly as CKD stages advanced (P = 0.018). There was a statistically significant reverse correlation between 8-isoprostane and glomerular filtration rate (GFR; r = .0.275; P = 0.014), but not between 8-isoprostane and Creactive protein (r = .0.183; P = 0.177).Conclusions: We determined the level of 8-isoprostane in EBC of patients with different stages of CKD and showed that the level of 8-isoprostane significantly increased through the progress of CKD. We consider that our study is important because there have been limited number of studies that evaluate oxidative stress in CKD using EBC which is a noninvasive method.Key words: 8-isoprostane, chronic kidney disease, exhaled breath condensate, oxidative stres
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