Understanding of Authorship by the Post Graduate Medical Students at a Center in Bangladesh

Education on authorship was delivered and evaluated by pre test and post test questionnairen on 30 post graduate medical students at the Department of Anestheology, Dhaka Medical College, Bangladesh between January and June 2019 to understand the knowledge, skill and attitude of post graduate medical students on authorship. Result: Before intervention, majority (60%) of the students felt that who perform the research work should be the author of the article. But 40% students were divided and felt that who advised the design of the research (20%), who provided the grants (10%) and Chief/Head of the division (10%) should be the author of the article respectively. Maximum (70%) respondents did not know the order of authorship. Of 40% respondent felt that the PI should be always the first author and 40% don’t know the answer. Half of the students (50%) felt that keeping honorary author increased the opportunity of acceptance of publication. Of 36.7% and 13.3% of students felt that keeping honorary author increased the article’s value and made good relation to them to get some extra facility from them respectively. Of 20% participants were pressurized by lab head/head of department for inclusion of their name as an author. Half of the (56.7 %) respondents felt that the author’s contribution should be stated in the article. Only few 4 (13.3%) respondents said that their institute had guideline for authorship. However, after education 100% of students felt that who perform the research work should be only the author of the article. All (100%) respondents understood the order of authorship. Most of the students (86%) felt that PI should be always the first author. Of 100% respondent felt supervisor of the research should be the last author. All students (100%) felt author’s contribution should be mentioned in the article. All (100%) students did not want to include as author those who help in research design and secured grant; and they did not like to keep honorary author in their article. All (100%) students expressed that their institute had no guideline for authorship. After intervention, three groups of students were asked to write one page of article on Anesthesiology. Interestingly, they did not include any name in the author by line who were not participate or had any contribution in the writing. Conclusion: The comparative data between pre- and post-text have highlighted a general lack of understanding of the basic concept of authorship ethics which significantly improved after the intervention. The results also indicate that the education on authorship improved the awareness of postgraduate medical students in a particular centre

Effect of omega 3 fatty acid in infertile males with oligozoospermia

Background: Oligozoospermia is the cause of male infertility in 33.3% of cases. Omega-3 fatty acid has been utilized in infertility because of its widespread availability, low cost, and high safety profile. We intended to conduct a study to evaluate the efficacy of omega-3 fatty acid in oligozoospermia. Methods: A prospective comparative study was conducted in the outdoor of the department of reproductive endocrinology and infertility, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, from July 2022 to August 2023. A total of 70 Infertile males with oligozoospermia, were enrolled in the study. The participants were assigned to the omega-3 fatty acid group who was treated with omega-3 fatty acid 1 gm orally twice daily for 12 weeks. The other group was treated with placebo orally twice daily for 12 weeks. Sixty patients completed the 12 weeks of treatment. The changes in sperm count were determined. Results: The mean age of the participants was 35.6±4.59 years. Following treatment with omega-3 fatty acid significant improvement was observed in sperm count from 11.10±2.81 million/ml to 34.2±31.36 million/ml. Significant improvement in total motile sperm count was also observed. At the end of 12 weeks of treatment 76.7% of participants in the omega 3 fatty acid group and 10.0% in the placebo group had normozoospermia. Conclusions: Supplementation with omega-3 fatty acid results in improvement of sperm concentration and total motile sperm count in infertile men with oligozoospermia

The investigation of absolute proper motions of the XPM Catalogue

The XPM-1.0 is the regular version of the XPM catalogue. In comparison with XPM the astrometric catalogue of about 280 millions stars covering entire sky from -90 to +90 degrees in declination and in the magnitude range 10^m<B<22^m is something improved. The general procedure steps were followed as for XPM, but some of them are now performed on a more sophisticated level. The XPM-1.0 catalogue contains star positions, proper motions, 2MASS and USNO photometry of about 280 millions of the sources. We present some investigations of the absolute proper motions of XPM-1.0 catalogue and also the important information for the users of the catalogue. Unlike previous version, the XPM-1.0 contains the proper motions over the whole sky without gaps. In the fields, which cover the zone of avoidance or which contain less than of 25 galaxies a quasi absolute calibration was performed. The proper motion errors are varying from 3 to 10 mas/yr, depending on a specific field. The zero-point of the absolute proper motion frame (the absolute calibration) was specified with more than 1 million galaxies from 2MASS and USNO-A2.0. The mean formal error of absolute calibration is less than 1 mas/yr.Comment: 11 pages, 9 figures, accepte

Deep optical observations of the central X-ray source in the Puppis A supernova remnant

X-ray observations reveiled a group of radio-silent isolated neutron stars (INSs) at the centre of young supernova remnants (SNRs), dubbed central compact objects or CCOs, with properties different from those of classical rotation-powered pulsars. In at least three cases, evidence points towards CCOs being low-magnetized INSs, born with slow rotation periods, and possibly accreting from a debris disc of material formed out of the supernova event. Understanding the origin of the diversity of the CCOs can shed light on supernova explosion and neutron star formation models. Optical/infrared (IR) observations are crucial to test different CCO interpretations. The aim of our work is to perform a deep optical investigation of the CCO RX J0822.0-4300 in the Puppis A SNR, one of the most poorly understood in the CCO family. By using as a reference the Chandra X-ray coordinates of RX J0822.0-4300, we performed deep optical observations in the B, V and I bands with the Very Large Telescope (VLT). We found no candidate optical counterpart within 3 sigma of the computed Chandra X-ray position down to 5 sigma limits of B~27.2, V~26.9, and I~25.6, the deepest obtained in the optical band for this source. These limits confirm the non-detection of a companion brighter than an M5 dwarf. At the same time, they do not constrain optical emission from the neutron star surface, while emission from the magnetosphere would require a spectral break in the optical/IR.Comment: 4 pages, 2 figures, Astronomy and Astrophysics, accepte

Cosmic Optical Background: the View from Pioneer 10/11

We present the new constraints on the cosmic optical background (COB) obtained from an analysis of the Pioneer 10/11 Imaging Photopolarimeter (IPP) data. After careful examination of data quality, the usable measurements free from the zodiacal light are integrated into sky maps at the blue (~0.44 um) and red (~0.64 um) bands. Accurate starlight subtraction is achieved by referring to all-sky star catalogs and a Galactic stellar population synthesis model down to 32.0 mag. We find that the residual light is separated into two components: one component shows a clear correlation with thermal 100 um brightness, while another betrays a constant level in the lowest 100 um brightness region. Presence of the second component is significant after all the uncertainties and possible residual light in the Galaxy are taken into account, thus it most likely has the extragalactic origin (i.e., the COB). The derived COB brightness is (1.8 +/- 0.9) x 10^(-9) and (1.2 +/- 0.9) x 10^(-9) erg/s/cm2/sr/A at the blue and red band, respectively, or 7.9 +/- 4.0 and 7.7 +/- 5.8 nW/m2/sr. Based on a comparison with the integrated brightness of galaxies, we conclude that the bulk of the COB is comprised of normal galaxies which have already been resolved by the current deepest observations. There seems to be little room for contributions of other populations including "first stars" at these wavelengths. On the other hand, the first component of the IPP residual light represents the diffuse Galactic light (DGL) - scattered starlight by the interstellar dust. We derive the mean DGL-to-100 um brightness ratios of 2.1 x 10^(-3) and 4.6 x 10^(-3) at the two bands, which are roughly consistent with the previous observations toward denser dust regions. Extended red emission in the diffuse interstellar medium is also confirmed.Comment: Accepted for publication in the Astrophysical Journal; Typos correcte

Pictor A (PKS 0518-45) - From Nucleus to Lobes

We present radio and optical imaging and kinematic data for the radio galaxy Pictor A, including HST continuum and [OIII], emission-line images (at a resolution of 25 - 100 mas) and ground-based imaging and spectroscopy (at a resolution of ~ 1.5". The radio data include 3 cm Australia Telescope images of the core, at a resolution comparable to that of the optical, ground-based images, and a VLBI image of a jet in the compact core (at a resolution of 2 - 25 mas), which seems to align with a continuum ``jet'' found in the HST images. The core radio jet, the HST optical continuum ``jet'', and the NW H-alpha filaments all appear to point toward the optical-synchrotron hot-spot in the NW lobe of this object and are associated with a disrupted velocity field in the extended ionized gas. The ground-based spectra which cover this trajectory also yield line ratios for the ionized gas which have anomalously low [NII] (6564), suggesting either a complex, clumpy structure in the gas with a higher cloud-covering factor at larger radii and with denser clouds than is found in the nuclear regions of most NLRG and Seyfert 2 galaxies, or some other, unmodeled, mechanism for the emergent spectrum from this region. The H-alpha emission-line filaments to the N appear to be associated with a 3 cm radio continuum knot which lies in a gap in the filaments ~ 4" from the nucleus. Altogether, the data in this paper provide good circumstantial evidence for non-disruptive redirection of a radio jet by interstellar gas clouds in the host galaxy.Comment: 19 pages, 6 ps.gz fig pages, to appear in the Ap.J. Supp

1ES 0229+200: An extreme blazar with a very high minimum Lorentz factor

The blazar 1ES 0229+200 is a high frequency peaked BL Lac object with a hard TeV spectrum extending to 10 TeV. Its unusual spectral characteristics make it a frequently used probe for intergalactic radiation and magnetic fields. With new, simultaneous observations in the optical, ultraviolet (UV) and X-rays, the synchrotron emission is probed in great detail. The X-ray emission varies by a factor of ~2 in 2009, while being rather stable in 2010. The X-ray spectrum is very hard (\Gamma ~ 1.8) and it shows an indication of excess absorption above the Galactic value. The X-ray emission is detected up to ~100 keV without any significant cut-off, thus 1ES 0229+200 belongs to the class of extreme blazars. The simultaneous measured, host galaxy- and extinction-corrected optical and UV fluxes illustrate that the cut-off of the low energy part of the synchrotron emission is located in the UV regime. The minimum energy of the electron distribution has to be rather high to account for this cut-off. This implies that there is a narrow-band energy distribution function of radiating electrons, which is responsible for the unusually hard TeV spectrum. Other extreme blazars have similar synchrotron peak frequencies but much softer TeV spectra, hence 1ES 0229+200 has one of the highest inverse Compton (IC) peak frequency and the narrowest electron distribution among the extreme blazars known to date.Comment: accepted for publication in Astronomy&Astrophysic

A low luminosity state in the massive X-ray binary SAX J0635+0533

The X-ray pulsar SAX J0635+0533 was repeatedly observed with the XMM-Newton satellite in 2003-2004. The precise localization provided by these observations confirms the association of SAX J0635+0533 with a Be star. The source was found, for the first time, in a low intensity state, a factor ~30 lower than that seen in all previous observations. The spectrum, well fitted by an absorbed power law with photon index ~1.7 and N_H = 1.2x10^22 cm^-2, was compatible with that of the high state. The low flux did not allow the detection of the pulsations at 33.8 ms seen BeppoSAX and RXTE data. In view of the small luminosity observed in 2003-2004, we reconsider the peculiarities of this source in both the accretion and rotation powered scenarios.Comment: Accepted for publication on Astronomy and Astrophysic

The Optical Spectrum of the Vela Pulsar

Our knowledge of the optical spectra of Isolated Neutron Stars (INSs) is limited by their intrinsic faintness. Among the fourteen optically identified INSs, medium resolution spectra have been obtained only for a handful of objects. No spectrum has been published yet for the Vela pulsar (PSR B0833-45), the third brightest (V=23.6) INS with an optical counterpart. Optical multi-band photometry underlines a flat continuum.In this work we present the first optical spectroscopy observations of the Vela pulsar, performed in the 4000-11000 A spectral range.Our observations have been performed at the ESO VLT using the FORS2 instrument. The spectrum of the Vela pulsar is characterized by a flat power-law (alpha = -0.04 +/- 0.04), which compares well with the values obtained from broad-band photometry. This confirms, once more, that the optical emission of Vela is entirely of magnetospheric origin. The comparison between the optical spectral indeces of rotation-powered INSs does not show evidence for a spectral evolution suggesting that, as in the X-rays, the INS aging does not affect the spectral properties of the magnetospheric emission. At the same time, the optical spectral indeces are found to be nearly always flatter then the X-rays ones, clearly suggesting a general spectral turnover at lower energies.Comment: 7 pages, 8 figures, accepted for publication in A&

The volume densities of giant molecular clouds in M83

Using observed GALEX far-ultraviolet (FUV) fluxes and VLA images of the 21-cm HI column densities, along with estimates of the local dust abundances, we measure the volume densities of a sample of actively star-forming giant molecular clouds (GMCs) in the nearby spiral galaxy M83 on a typical resolution scale of 170 pc. Our approach is based on an equilibrium model for the cycle of molecular hydrogen formation on dust grains and photodissociation under the influence of the FUV radiation on the cloud surfaces of GMCs. We find a range of total volume densities on the surface of GMCs in M83, namely 0.1 - 400 cm-3 inside R25, 0.5 - 50 cm-3 outside R25 . Our data include a number of GMCs in the HI ring surrounding this galaxy. Finally, we discuss the effects of observational selection, which may bias our results.Comment: 9 pages, 11 figure