5,255 research outputs found

    Diffraction-limited Subaru imaging of M82: sharp mid-infrared view of the starburst core

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    We present new imaging at 12.81 and 11.7 microns of the central ~40"x30" (~0.7x0.5 kpc) of the starburst galaxy M82. The observations were carried out with the COMICS mid-infrared (mid-IR) imager on the 8.2m Subaru telescope, and are diffraction-limited at an angular resolution of <0".4. The images show extensive diffuse structures, including a 7"-long linear chimney-like feature and another resembling the edges of a ruptured bubble. This is the clearest view to date of the base of the kpc-scale dusty wind known in this galaxy. These structures do not extrapolate to a single central point, implying multiple ejection sites for the dust. In general, the distribution of dust probed in the mid-IR anticorrelates with the locations of massive star clusters that appear in the near-infrared. The 10-21 micron mid-IR emission, spatially-integrated over the field of view, may be represented by hot dust with temperature of ~160 K. Most discrete sources are found to have extended morphologies. Several radio HII regions are identified for the first time in the mid-IR. The only potential radio supernova remnant to have a mid-IR counterpart is a source which has previously also been suggested to be a weak active galactic nucleus. This source has an X-ray counterpart in Chandra data which appears prominently above 3 keV and is best described as a hot (~2.6 keV) absorbed thermal plasma with a 6.7 keV Fe K emission line, in addition to a weaker and cooler thermal component. The mid-IR detection is consistent with the presence of strong [NeII]12.81um line emission. The broad-band source properties are complex, but the X-ray spectra do not support the active galactic nucleus hypothesis. We discuss possible interpretations regarding the nature of this source.Comment: Accepted for publication in PASJ Subaru special issue. High resolution version available temporarily at http://www.astro.isas.jaxa.jp/~pgandhi/pgandhi_m82.pd

    Deregulated JAK/STAT signalling in lymphomagenesis, and its implications for the development of new targeted therapies

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    Gene expression profiling has implicated several intracellular signalling cascades, including the JAK/STAT pathway, in the pathogenesis of particular subtypes of lymphoma. In marked contrast to the situation in patients with either acute lymphoblastic leukaemia or a myeloproliferative neoplasm, JAK2 coding sequence mutations are rare in lymphoma patients with an activated JAK/STAT “signature”. This is instead the consequence of mutational events that result in the increased expression of non-mutated JAK2; positively or negatively affect the activity of other components of the JAK/STAT pathway; or establish an autocrine signalling loop that drives JAK-mediated cytokine-independent proliferation. Here, we detail these genetic lesions, their functional consequences, and impact on patient outcome. In light of the approval of a JAK1/JAK2 inhibitor for the treatment of myelofibrosis, and preliminary studies evaluating the efficacy of other JAK inhibitors, the therapeutic potential of compounds that target JAK/STAT signalling in the treatment of patients with lymphoma is also discussed

    Prescribing pattern of analgesics used for postoperative pain and its correlate with patient and doctor satisfaction:

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    Background: Post operative pain is difficult to assessment and its management has been neglected at times. Moreover, the drug treatment involves administration of drug on as and when basis which leads to inadequate control. Methods: This observational, prospective study was conducted in 100 post-operative patients i.e., 50 each from surgery and orthopedics departments. Investigator enrolled post-operative patients within 24 hours of surgery and followed them for next 5 days or till hospital discharge, whichever was earlier. Analgesic prescribing pattern, self-assessment of pain, patient and doctor satisfaction using ASSIST questionnaire were recorded in Case Record Form and analysed. Results: Out of 100 patients, average number of analgesics prescribed post-operatively was 1.49±0.5 (baseline and all follow-up). 76.5% patients received NSAIDs which included diclofenac (44.29%) and paracetamol (30.87%). Opioids in the form of tramadol were prescribed in 23.49% patients. Mean least pain experienced by patients on day 1 was 2±0.75 which decreased to 1.32±0.63 on day 5. Mean worst pain decreased from 6.64±1.43 on day 1 to 3.38±1.17 on day 5. Average percentage of duration of severe pain was 35.2%±16.48 on day 1 which successively decreased to 16.32±8.26 on day 5. Average pain relief observed in 62.3% patients on day one increased to 80.88% on day 5. Patient satisfaction increased as pain score decreased (r=-0.73) and a strong positive correlation was observed between doctor satisfaction and patient satisfaction (r=0.91). Conclusions: Inadequate control of post-operative pain affects effective patient management and recovery. Incorporation of effective pain assessment scores in pain management is desirable

    Classification of EEG signals on standing, walking and running dataset using LSTM-RNN

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    Undoubtedly one of the most important strands of the brain-computer interface (BCI) method is an alternate communication method via brain signals. BCI converts electroencephalogram (EEG) signals from a perception of activity in the brain into user action utilising software and hardware. BCI has piqued the interest of researchers in a wide range of disciplines, such as cognitive science, deep learning, pattern matching, drug treatment medicine, etc. Patients suffering from neuro and cognitive disorders can be assisted through BCI, potentially enabling communication via gestures or just mental imagination. In this paper, a novel combination of Discrete Wavelet Transform (DWT) for extracting the best features and Long Short-Term Memory (LSTM) based Recurrent Neural Network (RNN) is adopted for classifying the EEG signals acquired during standing, walking and running on a treadmill. The dataset used is freely downloaded from Open Science Framework repository. The proposed DWT-LSTMRNN method delivers 96.7% accuracy while classifying four different signals, and thus has the potential to be investigated further on BCI competition datasets that will pave way for a real-time application

    Observations on whale shark Rhineodon typus (Smith) caught at Pamban, Palk Bay and Gulf of Mannar

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    A male whale shark Rhineodon typus of 688 cm in total length caught in a No.4 gill net was landed on 20-01 -2001 at Pamban light house landing centre. The whale shark was estimated to weigh around 1.5 tonnes

    Environmental Conditions off Karaikal, South-East Coast of India, as Deciphered from Recent Benthic Foraminiferal Distributions

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    Bottom water and sediment samples collected from off Karaikal, Arasalar River mouth and further upstream revealed that the environmental conditions control the distribution of benthic foraminiferal populations. In the offshore region, although Ammonia beccarii dominates the assemblage, depth of the water column seems to play a significant role in controlling the distribution of taxa constituting the assemblage. Within the depth range of sampling, a general increase in total populations of this species is observed. The nearshore stations are characterized by relatively higher total populations of such species as Spiroloculina orbis, Pararotalia nipponica and Elphidium crispum, all of which typically inhabit shallow waters on the east coast of India. Both living and total populations of all the species put together show a definite increase with depth of the water column; the maximum living and total populations have been counted to be 36 and 328, respectively. In proximity to the Arasalar River mouth also, A. beccarii predominates the assemblage which, however, is similar to those recorded from estuaries in the Indian region. The assemblage recorded from the upstream samples with relatively increased DO content but decreased salinities is still dominated by the same species, but its associated taxa are characteristic of euhaline to meso-polyhaline environmental conditions. The present study reiterates the need for examining modern benthic foraminiferal distributions and the assemblages therein from diverse environments, in order to facilitate better interpretation of fossil assemblages. Keywords Foraminifera , Distribution ,Environment ,Karaikal , SE coast of  Indi

    Serendipitous discovery of an extended X-ray jet without a radio counterpart in a high-redshift quasar

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    A recent Chandra observation of the nearby galaxy cluster Abell 585 has led to the discovery of an extended X-ray jet associated with the high-redshift background quasar B3 0727+409, a luminous radio source at redshift z=2.5. This is one of only few examples of high-redshift X-ray jets known to date. It has a clear extension of about 12", corresponding to a projected length of ~100 kpc, with a possible hot spot located 35" from the quasar. The archival high resolution VLA maps surprisingly reveal no extended jet emission, except for one knot about 1.4" from the quasar. The high X-ray to radio luminosity ratio for this source appears consistent with the (1+z)4\propto (1+z)^{4} amplification expected from the inverse Compton radiative model. This serendipitous discovery may signal the existence of an entire population of similar systems with bright X-ray and faint radio jets at high redshift, a selection bias which must be accounted for when drawing any conclusions about the redshift evolution of jet properties and indeed about the cosmological evolution of supermassive black holes and active galactic nuclei in general

    Heavy boson production through the collision of an ultrahigh-energy neutrino on a target nucleon

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    We discuss W and Z production through the deep inelastic neutrino-nucleon scattering in the context of the standard model SU(3)x SU(2)x U(1) of the strong and electroweak interactions. We find the cross section rates for the process neutrino + nucleon --> lepton(-) + W(+) + X for the case of ultrahigh-energy neutrinos colliding on a target nucleon.Comment: 20 pages, 6 figure

    Heavy landings of the filefish Aluterus monoceros from the Gulf of Mannar

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    Heavy landings of the unicorn leatherjacket filefish, Aluterus monoceros (Linnaeus, 1758) was observed at Pamban Therkuvady fish landing centre, landed by trawlers operating in Gulf of Manna
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