1,091 research outputs found
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
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