185 research outputs found
ASASSN-14dq: A fast-declining type II-P Supernova in a low-luminosity host galaxy
Optical broadband (UBVRI) photometric and low-resolution spectroscopic
observations of the type II-P supernova (SN) ASASSN-14dq are presented.
ASASSN-14dq exploded in a low-luminosity/metallicity host galaxy UGC 11860, the
signatures of which are present as weak iron lines in the photospheric phase
spectra. The SN has a plateau duration of 90 d, with a plateau decline
rate of 1.38 in V-band which is higher than most type
II-P SNe. ASASSN-14dq is a luminous type II-P SN with a peak -band absolute
magnitude of -17.70.2 mag. The light curve of ASASSN-14dq indicates it
to be a fast-declining type II-P SN, making it a transitional event between the
type II-P and II-L SNe. The empirical relation between the steepness parameter
and mass for type II SNe was rebuilt with the help of
well-sampled light curves from the literature. A mass of
0.029 M was estimated for ASASSN-14dq, which is slightly
lower than the expected mass for a luminous type II-P SN. Using
analytical light curve modelling, a progenitor radius of cm, an ejecta mass of and a total
energy of ergs was estimated for this event. The
photospheric velocity evolution of ASASSN-14dq resembles a type II-P SN, but
the Balmer features (H and H) show relatively slow velocity
evolution. The high-velocity H feature in the plateau phase, the
asymmetric H emission line profile in the nebular phase and the
inferred outburst parameters indicate an interaction of the SN ejecta with the
circumstellar material (CSM).Comment: 28 pages, 29 figures, Accepted in MNRA
Direction of Association Between Depressive Symptoms and Lifestyle Behaviors in Patients with Coronary Heart Disease: the Heart and Soul Study
Emerging evidence indicates that the association between depression and subsequent cardiovascular events is largely mediated by health behaviors. However, it is unclear whether depression is the cause or the consequence of poor health behaviors
Type Ia supernovae SN 2013bz, PSN J0910+5003 and ASASSN-16ex: similar to 09dc-like?
We present optical photometric and spectroscopic studies of three supernovae
(SNe) SN 2013bz, PSN J0910+5003 and ASASSN-16ex. UV-optical photometric data of
ASASSN-16ex obtained with Swift-UVOT are also analyzed. These objects were
initially classified as 09dc-like type Ia SNe. The decline rate parameters
() are derived as 0.92 0.04 (SN 2013bz), 0.70
0.05 (PSN J0910+5003) and 0.73 0.03 (ASASSN-16ex). The estimated
band absolute magnitudes at maximum: 19.61 0.20 mag for SN 2013bz,
19.44 0.20 mag for PSN J0910+5003 and 19.78 0.20 mag for
ASASSN-16ex indicate that all the three objects are relatively bright. The peak
bolometric luminosities for these objects are derived as 43.38 0.07 erg s, 43.26 0.07 erg
s and 43.40 0.06 erg s, respectively. The spectral and
velocity evolution of SN 2013bz is similar to a normal SN Ia, hence it appears
to be a luminous, normal type Ia supernova. On the other hand, the light curves
of PSN J0910+5003 and ASASSN-16ex are broad and exhibit properties similar to
09dc-like SNe Ia. Their spectroscopic evolution shows similarity with 09dc-like
SNe, strong CII lines are seen in the pre-maximum spectra of these two events.
Their photospheric velocity evolution is similar to SN 2006gz. Further, in the
UV bands, ASASSN-16ex is very blue like other 09dc-like SNe Ia.Comment: 19 pages, 20 figures, accepted for publication in MNRA
GBJOF: Gradient Boosting Integrated with Jaya Algorithm to Optimize the Features in Malware Analysis
Malware analysis is used to identify suspicious file transferring in the network. It can be identified efficiently by using the reverse engineering hybrid approach. Implementing a hybrid approach depends on the feature selection because the dataset contains static and dynamic parameters. The given dataset contains 85 attributes with 10 different class labels. Since it has high dimensional and multi-classification data, existing approaches of ML could be more efficient in reducing the features. The model combines the enhanced JAYA genetic algorithm with a gradient boosting technique to identify the efficiency and a smaller number of features. Many existing approaches for feature selection either implement correlation analysis or wrapper techniques. The major disadvantages of these issues are that they are facing fitting problems with a very small number of features. With the Usage of the genetic approach, this paper has achieved 95% accuracy with 12 features, approximately 7% greater than ML approaches
Genetically Encoded Spy Peptide Fusion System to Detect Plasma Membrane-Localized Proteins In Vivo
Membrane proteins are the main gatekeepers of cellular state, especially in neurons, serving either to maintain homeostasis or instruct response to synaptic input or other external signals. Visualization of membrane protein localization and trafficking in live cells facilitates understanding the molecular basis of cellular dynamics. We describe here a method for specifically labeling the plasma membrane-localized fraction of heterologous membrane protein expression using channelrhodopsins as a case study. We show that the genetically encoded, covalent binding SpyTag and SpyCatcher pair from the Streptococcus pyogenes fibronectin-binding protein FbaB can selectively label membrane-localized proteins in living cells in culture and in vivo in Caenorhabditis elegans. The SpyTag/SpyCatcher covalent labeling method is highly specific, modular, and stable in living cells. We have used the binding pair to develop a channelrhodopsin membrane localization assay that is amenable to high-throughput screening for opsin discovery and engineering
SN 2018gj: A Short-plateau Type II Supernova with Persistent Blue-shifted H-alpha Emission
We present an extensive, panchromatic photometric (UV, Optical, and NIR) and
low-resolution optical spectroscopic coverage of a Type IIP supernova SN 2018gj
that occurred on the outskirts of the host galaxy NGC 6217. From the V-band
light curve, we estimate the plateau length to be ~ 70 +- 2 d, placing it among
the very few well-sampled short plateau supernovae (SNe). With V-band peak
absolute magnitude Mv < -17.0 +- 0.1 mag, it falls in the middle of the
luminosity distribution of the Type II SNe. The colour evolution is typical to
other Type II SNe except for an early elbow-like feature in the evolution of
V-R colour owing to its early transition from the plateau to the nebular phase.
Using the expanding photospheric method, we present an independent estimate of
the distance to SN 2018gj. We report the spectral evolution to be typical of a
Type II SNe. However, we see a persistent blue shift in emission lines until
the late nebular phase, not ordinarily observed in Type II SNe. The amount of
radioactive nickel (56Ni) yield in the explosion was estimated to be 0.026 +-
0.007 Msol. We infer from semi-analytical modelling, nebular spectrum, and 1-D
hydrodynamical modelling that the probable progenitor was a red supergiant with
a zero-age-main-sequence mass < 13 Msol. In the simulated hydrodynamical model
light curves, reproducing the early optical bolometric light curve required an
additional radiation source, which could be the interaction with the proximal
circumstellar matter (CSM).Comment: Accepted for publication in ApJ (31 pages, 23 figures and 7 tables
Anti-anaphylactic and mast cell stabilizing effect of <i>Calotropis gigantea</i> extract
Calotropis gigantea (Linn.) R.Br. (Asclepiadaceae), commonly known as milkweed or swallow- wort, is found chiefly in wasteland throughout India. It has been reported as a traditional folkloric medicine in treatment of asthma in the Indian literature. Roots containing α-and β-amyrin are reported to possess anti-lipoxygenase activity. Hence, our objective was to evaluate the effect of the methanolic extract of Calotropis gigantea (CG) root on egg albumin induced passive paw anaphylaxis and compound 48/80 induced mast cell degranulation in rats. CG were given at doses of 100, 200, 400 mg/kg, p.o., to rats. We found that CG significantly increases percentage inhibition of paw edema volume at all doses but shows significant percentage protection of the mast cells at 400 mg/kg. p.o., to rats. Hence, the present investigation confirm the use of CG as anti-anaphylactic and mast cell stabilizing in treatment of asthma.Colegio de Farmacéuticos de la Provincia de Buenos Aire
SN 2015ba: A type IIP supernova with a long plateau
We present optical photometry and spectroscopy from about a week after
explosion to 272 d of an atypical Type IIP supernova, SN 2015ba, which
exploded in the edge-on galaxy IC 1029. SN 2015ba is a luminous event with an
absolute V-band magnitude of -17.10.2 mag at 50 d since explosion and has
a long plateau lasting for 123 d. The distance to the SN is estimated to
be 34.80.7 Mpc using the expanding photosphere and standard candle
methods. High-velocity H-Balmer components constant with time are observed in
the late-plateau phase spectra of SN 2015ba, which suggests a possible role of
circumstellar interaction at these phases. Both hydrodynamical and analytical
modelling suggest a massive progenitor of SN 2015ba with a pre-explosion mass
of 24-26 M. However, the nebular spectra of SN 2015ba exhibit
insignificant levels of oxygen, which is otherwise expected from a massive
progenitor. This might be suggestive of the non-monotonical link between O-core
masses and the zero-age main-sequence mass of pre-supernova stars and/or
uncertainties in the mixing scenario in the ejecta of supernovae.Comment: 42 pages, 7 pages Appendix, 20 figures, 10 tables, Accepted for
publication in MNRAS, 14-June-201
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