4,359 research outputs found
Impact of Tandem Repeats on the Scaling of Nucleotide Sequences
Techniques such as detrended fluctuation analysis (DFA) and its extensions
have been widely used to determine the nature of scaling in nucleotide
sequences. In this brief communication we show that tandem repeats which are
ubiquitous in nucleotide sequences can prevent reliable estimation of possible
long-range correlations. Therefore, it is important to investigate the presence
of tandem repeats prior to scaling exponent estimation.Comment: 14 Pages, 3 Figure
Mesalazine induced myocarditis: a case report
Background: Myocarditis is a rare complication of therapy with mesalazine, a drug widely prescribed in the treatment of inflammatory bowel disease. Case presentation: We report a case of myocarditis occurring in a 49-year-old British man 10 days following initiation of mesalazine therapy for treatment of ulcerative colitis. He presented with troponin-positive chest pain, and the diagnosis of myocarditis was confirmed on the basis of cardiac magnetic resonance imaging, which showed subepicardial delayed gadolinium enhancement in the basal to middle inferior and inferolateral segments of the heart. The patient’s symptoms and condition improved upon stopping mesalazine, and he made a full recovery. Conclusions: Mesalazine-induced myocarditis may be more common than first appreciated and is potentially fatal. Therefore, it is imperative that clinicians be aware of this potentially life-threatening adverse effect of mesalazine therapy and warn patients to seek urgent medical attention if cardiac symptoms arise
On the Origin of the Wide HI Absorption Line Toward Sgr A*
We have imaged a region of about 5' extent surrounding Sgr A* in the HI 21
cm-line absorption using the Very Large Array. A Gaussian decomposition of the
optical depth spectra at positions within about 2' (approx. 5 pc at 8.5 kpc) of
Sgr A* detects a wide line underlying the many narrow absorption lines. The
wide line has a mean peak optical depth of 0.32 +/- 0.12 centered at a mean
velocity of V(lsr) = -4 +/- 15 km/s. The mean full width at half maximum is 119
+/- 42 km/s. Such a wide line is absent in the spectra at positions beyond
about 2' from Sgr A*. The position-velocity diagrams in optical depth reveal
that the wide line originates in various components of the circumnuclear disk
(radius approx. 1.3') surrounding Sgr A*. These components contribute to the
optical depth of the wide line in different velocity ranges. The
position-velocity diagrams do not reveal any diffuse feature which could be
attributed to a large number of HI clouds along the line of sight to Sgr A*.
Consequently, the wide line has no implications either to a global population
of shocked HI clouds in the Galaxy or to the energetics of the interstellar
medium as was earlier thought.Comment: LaTeX, 12 pages and 9 figures, accepted for publication in J.
Astrophys. Ast
Polarized radio emission from the magnetar XTE J1810-197
We have used the Parkes radio telescope to study the polarized emission from
the anomalous X-ray pulsar XTE J1810-197 at frequencies of 1.4, 3.2, and 8.4
GHz. We find that the pulsed emission is nearly 100% linearly polarized. The
position angle of linear polarization varies gently across the observed pulse
profiles, varying little with observing frequency or time, even as the pulse
profiles have changed dramatically over a period of 7 months. In the context of
the standard pulsar "rotating vector model," there are two possible
interpretations of the observed position angle swing coupled with the wide
profile. In the first, the magnetic and rotation axes are substantially
misaligned and the emission originates high in the magnetosphere, as seen for
other young radio pulsars, and the beaming fraction is large. In the second
interpretation, the magnetic and rotation axes are nearly aligned and the line
of sight remains in the emission zone over almost the entire pulse phase. We
deprecate this possibility because of the observed large modulation of thermal
X-ray flux. We have also measured the Faraday rotation caused by the Galactic
magnetic field, RM = +77 rad/m^2, implying an average magnetic field component
along the line of sight of 0.5 microG.Comment: Accepted for publication in ApJ Letters. Six pages with 4 figure
Self-consistency of relativistic observables with general relativity in the white dwarf-neutron star binary pulsar PSR J1141-6545
Here we report timing measurements of the relativistic binary pulsar PSR
J1141-6545 that constrain the component masses and demonstrate that the orbital
period derivative \dot Pb = (-4+/-1)x10^-13 is consistent with gravitational
wave emission as described by the general theory of relativity. The mass of the
neutron star and its companion are 1.30+/-0.02 Mo and 0.986+/-0.020 Mo
respectively, suggesting a white dwarf companion, and extending the range of
systems for which general relativity provides a correct description. On
evolutionary grounds, the progenitor mass of PSR J1141-6545 should be near the
minimum for neutron star production. Its mass is two standard deviations below
the mean of the other neutron stars, suggesting a relationship between
progenitor and remnant masses.Comment: 10 pages, 2 figures, revised version to Ap J Letter
Sero Diagnosis of Tuberculosis in Children Using Two ELISA Kits
The diagnosis of childhood tuberculosis is based on circumstantial evidence in the
absence of a gold standard in the majority of cases. Sero-diagnosis offers scope for an early
diagnosis in a variety of clinical conditions and is simple to perform. A number of mycobacterial
antigens have been used for antibody detection assays and several are available as kits in the
market. This study was done to evaluate the value of antibody detection kits (ELISA) against the
A60 antigen and 38kDa antigen of Mycobacterium tuberculosis in the diagnosis of childhood
tuberculosis at the outpatient department of the Institute of Social Paediatrics, Government Stanley
Hospital in collaboration with Tuberculosis Research Centre, Chennai. Thirty five children with
pulmonary tuberculosis, 7 with TB lymphadenitis and 22 healthy controls were studied. In addition
to routine investigations including gastric lavage for AFB culture, serum antibodies against the A60
and 38kDa antigens were assayed using commercially available ELISA kits. With A60, IgM serum
levels were positive in 74% of pulmonary TB cases, 57% of TB lymphadenitis cases and 50% of
controls. A60 IgG was positive in 17% of pulmonary TB, 86% of TB lymphadenitis and 14% of
controls. The 38 kDa IgG antibody was positive in 37% of pulmonary and 86% of TB lymphadenitis
cases and 27% of controls. Among 10 culture confirmed cases, A60 IgM was positive in 8, A60 IgG
in 3 and 38kDa IgG in 5 patients. The sensitivity of the tests ranged between 29% and 71% and
specificity between 50% and 86%. Although the numbers are small, the results suggest that
serodiagnosis using the currently available antigens of M. tuberculosis is unlikely to be a
confirmatory test for tuberculosis in children
Role of Imaging in Acute Ischemic Stroke
Rapid multimodal imaging is essential in the workup and management of acute ischemic stroke. Early parenchymal findings on noncontrast computed tomography or standard magnetic resonance imaging are used to triage patients for intravenous thrombolysis and to provide insight on prognosis. In the wake of recent endovascular stroke trials, advanced techniques including perfusion imaging and noninvasive vascular imaging are becoming important tools to guide potential endovascular treatment or expand therapy windows. Advanced imaging is also important in pediatric ischemic stroke which requires a slightly different workflow and treatment approach. Here, we will discuss key imaging findings in acute ischemic stroke, as well as the present and future of neuroimaging in light of recent and ongoing clinical trials
Bioactive potential of actinobacteria isolated from the gut of marine fishes
1280-1285The study was undertaken to explore the gut-associated actinobacteria from two marine fish with special reference to antimicrobial and anti-quorum sensing activity. A total of 40 actinobacterial strains were isolated from fish gut samples using starch casein agar and Kuster’s agar medium. About 14 morphologically different strains recovered from Rastrelliger kanagurta (Indian mackerel) and Panna microdon (Panna croaker) were screened for the antimicrobial activity against Staphylococcus aureus MTCC96, Escherichia coli MTCC739, Salmonella enterica, Candida albicans, and quorum sensing inhibition (QSI) against Chromobacterium violaceum and Serratia marcescens. The actinobacterial strain IM20 from R. kanagurta showed both antimicrobial and QSI activity, whereas the strains PCA1 and PCA4 from P. microdon showed only antimicrobial activity. Strain IM20, which showed wide range of activity, was selected as the potential strain for further studies. Thus, the findings suggested that the fish-associated actinobacteria is a promising source for antimicrobial compounds for developing novel therapeutic drugs
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