118 research outputs found
How Do Lipids Localize in Lewy Bodies?
Lewy bodies are the pathological hallmark of Parkinson's disease (PD). While fibrillar α-synuclein (αS) is the main protein component of Lewy bodies, these structures also contain lipids. To elucidate the presence of lipids in Lewy bodies, we investigated the interaction of lipids with monomeric and fibrillar αS. In vitro, lipid membranes accelerated αS fibril formation under physiological conditions. Moreover lipids and small vesicles co-localized with supra-fibrillar structures and individual αS fibrils suggesting that aggregation initiates at the membrane. The presence of lipids in Lewy bodies may therefore be an indication that cell membranes are the major target in aggregation induced neuronal cell deat
Data Analysis of three parameter models of deceleration parameter in FRW Universe
Constraining the dark energy deceleration parameter is one of the fascinating
topics in the recent cosmological paradigm. This work aims to reconstruct the
dark energy using parametrization of the deceleration parameter in a flat FRW
universe filled with radiation, dark energy, and pressure-less dark matter.
Thus, we have considered four well-motivated parameterizations of q(z), which
can provide the evolution scenario from the deceleration to acceleration phase
of the Universe. We have evaluated the expression of the corresponding Hubble
parameter of each parametrization by imposing it into the Friedmann equation.
We have constrained the model parameter through H(z), Pantheon, and baryons
acoustic oscillation (BOA) data. Next, we have estimated the best-fit values of
the model parameters by using Monte Carlo Markov Chain (MCMC) technique and
implementing H(z)+ BAO+SNe-Ia dataset. Then we analyzed the cosmographic
parameter, such as deceleration, jerk, and snap parameters, graphically by
employing the best-fit values of the model parameter. Moreover, we have
analyzed statefinder and Om diagnostics parameters for each scenario to
discriminate various dark energy models. Using the information criteria, the
viability of the models have examined. In the end, we have analogized our
outcomes with the standard {\Lambda}CDM model to examine the viability of our
model
Model-independent study for a quintessence model of dark energy: Analysis and Observational constraints
In this paper, a well-motivated parametrization of the Hubble parameter (%
) is revisited that renders two models of dark energy showing some intriguing
features of the late-time accelerating Universe. A general quintessence field
is considered as a source of dark energy. We have obtained tighter constraints
using recently updated cosmic observational datasets for the considered models.
The two models described here show a nice fit to the considered uncorrelated
Hubble datasets, Standard candles, Gamma Ray Bursts, Quasars, and uncorrelated
Baryonic Acoustic Oscillations datasets. Using the constrained values of the
model parameters, we have discussed some features of the late-time accelerating
models and obtained the present value of the deceleration parameter (),
the present value of the Hubble parameter () and the transition redshift
() from deceleration to acceleration. The current value of the
deceleration parameter for both models is consistent with the Planck 2018
results. The evolution of the geometrical and physical parameters is discussed
through graphical representations for both models with some diagnostic
analysis. The statistical analysis performed here shows greater results and
overall, the outcomes of this investigation are superior to those previously
found.Comment: 22 pages, 26 figure
Constraints on the Parameterized Deceleration Parameter in FRW Universe
Confirmation of accelerated expansion of the universe probed the concept of
dark energy theory, and since then, numerous models have been introduced to
explain its origin and nature. The present work is based on reconstructing dark
energy by parametrization of the deceleration parameter in the FRW universe
filled with radiation, dark matter, and dark energy. We have chosen some
well-motivated parametrized models 1-3 in an attempt to investigate the energy
density in terms of deceleration parameters by estimating the cosmological
parameters with the help of different observational datasets. Also, we have
introduced a new model 4 for the parametrization of the deceleration parameter.
Then we analyzed the cosmography parameters using the best-fit values of the
parameters. Using the information criteria, we have examined the viability of
the models
A New Cosmological Model: Exploring the Evolution of the Universe and Unveiling Super-Accelerated Expansion
In this paper, we present a cosmological model designed to study the
evolution of the universe based on a new parametrization of the deceleration
parameter. The model considers a spatially flat, homogeneous, and isotropic
Friedmann-Lema\^itre-Robertson-Walker (FLRW) universe filled with radiation,
dark matter (DM), and dark energy (DE). We derive the Friedmann equations and
the energy conservation equation for the universe, accounting for separate
conservation equations for radiation, DM, and DE. Our proposed deceleration
parameter is given by a formula involving constants , ,
, , , , and . which we
subsequently fit to observational data. To assess the model's viability, we
compare it with a diverse range of observational data, including cosmic
chronometers, type Ia supernovae, baryon acoustic oscillations, and cosmic
microwave background measurements. Employing the chi-square statistic and a
Markov Chain Monte Carlo (MCMC) method, we estimate the best-fit values for the
free parameters and investigate the constraints imposed by observational data
on the model. Our results indicate that our cosmological model provides an
excellent fit to the observed data and exhibits a remarkable agreement with the
standard CDM paradigm at higher redshifts. However, the most
intriguing discovery lies in the model's prediction of a super-accelerated
expansion in the distant future, in contrast to the de Sitter phase predicted
by CDM. This implies the presence of dark energy driving the
universe's accelerated expansion. These findings suggest that our proposed
cosmological model offers a compelling alternative to the CDM
paradigm, shedding new light on the nature of dark energy and the future fate
of the cosmos.Comment: 10 figures, 2 table
Cosmological Tests of Dark Energy Model in FRW Universe
This research article presents a new cosmological model formulated within the
framework, focusing on the observational signatures and
parameter constraints of the model. The Markov Chain Monte Carlo (MCMC)
technique is employed to effectively explore the parameter space using data
from 36 Cosmic Chronometers and 1701 Pantheon Plus data points. A comparative
analysis is conducted between the proposed model and the
widely accepted CDM model, considering various cosmological
parameters, such as Deceleration, Snap, and Jerk. By evaluating these
parameters, valuable insights into the dynamics and evolution of the universe
within the context of the new model are obtained. Diagnostic tests including
Statefinder and Om Diagnostic are performed to further investigate the behavior
and consistency of the model. These tests provide deeper
insights into the properties of the model and its compatibility with
observational data. The model is subjected to statistical analysis using
Information Criteria to rigorously assess its goodness of fit to the data. This
analysis helps determine the level of agreement between the
model and the observational data, establishing the
viability and reliability of the proposed cosmological framework. The results
highlight the potential of the framework in understanding
the fundamental aspects of the universe's evolution and dynamics. The
comparative analysis with the CDM model, along with the comprehensive
diagnostic tests performed, demonstrates the efficacy and validity of the
model in explaining observed cosmological phenomena. These
findings contribute to the ongoing pursuit of accurate and comprehensive models
that provide a deeper understanding of the nature of our universe.Comment: 19 pages, 10 figures; accepted for publication in EPJ
Analyzing a higher order model and its implications in the late evolution of the Universe using recent observational datasets
In this research paper, we explore a well-motivated parametrization of the
time-dependent deceleration parameter, characterized by a cubic form, within
the context of late time cosmic acceleration. The current analysis is based on
the gravity theory, by considering the background metric as the
homogeneous and isotropic Friedmann Lema\^itre Robertson Walker (FLRW) metric.
Investigating the model reveals intriguing features of the late universe. To
constrain the model, we use the recent observational datasets, including cosmic
chronometer (CC), Supernovae (SNIa), Baryon Acoustic Oscillation (BAO), Cosmic
Microwave Background Radiation (CMB), Gamma Ray Burst (GRB), and Quasar (Q)
datasets. The joint analysis of these datasets results in tighter constraints
for the model parameters, enabling us to discuss both the physical and
geometrical aspects of the model. Moreover, we determine the present values of
the deceleration parameter (), the Hubble parameter (), and the
transition redshift () from deceleration to acceleration ensuring
consistency with some recent results of Planck 2018. Our statistical analysis
yields highly improved results, surpassing those obtained in previous
investigations. Overall, this study presents valuable insights into the higher
order model and its implications for late-time cosmic acceleration,
shedding light on the nature of the late universe
ASSESSMENT OF ADVERSE DRUG REACTIONS OF ANTIDEPRESSANT DRUGS USED IN PSYCHIATRY DEPARTMENT OF A TERTIARY CARE HOSPITAL
Objective: The aim of the study was to analyze adverse drug reactions (ADRs) reported in patients prescribed antidepressants at tertiary care hospital.
Methods: A prospective and observational study was conducted during January 2020–July 2021 at Department of Pharmacology in collaboration with the Department of Psychiatry, GSVM Medical College, and Kanpur. All patients diagnosed with depression and receiving pharmacotherapy were included in the study. ADRs were monitored using the standard form of the Central Drugs Standard Control Organization and causality was determined using the Naranjo algorithm. Data were evaluated for patient’s demography, risk factors for ADRs, and pattern of ADR.
Results: A total of 293 ADRs were recorded from 110 patients. The most common ADRs observed were anxiety (47.42%) and insomnia (19.22%). Men (58.18%) were most commonly affected than women (41.82%). The most common causal drugs among antidepressants were Escitalopram (27.27%) and Venlafaxine (21.81%), respectively. The most common system involved was central nervous system (53.24%) followed by gastrointestinal system (41.63%). The majority of ADRs (97.95%) were possible according to the Naranjo’s scale.
Conclusion: Anxiety, insomnia, and dizziness were the common ADRs which were associated with the use of antidepressants. This study offers a representative profile of the ADRs which can be expected in the psychiatry outpatients
Exploring Tidal Force Effects and Shadow Constraints for Schwarzschild-like Black Hole in Starobinsky-Bel-Robinson Gravity
The current manuscript deals with the tidal force effects, geodesic
deviation, and shadow constraints of the Schwarzschild-like black hole
theorised in Starobinsky-Bel-Robinson gravity exhibiting M-theory
compactification. In the current analysis, we explore the radial and angular
tidal force effects on a radially in-falling particle by the central black
hole, which is located in this spacetime. We also numerically solve the
geodesic deviation equation and study the variation of the geodesic separation
vector with the radial coordinate for two nearby geodesics using suitable
initial conditions. All the obtained results are tested for Sag A* and M87* by
constraining the value of the stringy gravity parameter using the
shadow data from the event horizon telescope observations. All the results are
compared with Schwarzschild black hole spacetime. In our study, we found that
both the radial and angular tidal forces experienced by a particle switch their
initial behaviour and turn compressive and stretching, respectively, before
reaching the event horizon. The geodesic deviation shows an oscillating trend
as well for the chosen initial condition. For the constrained value of ,
we see that the spacetime geometry generated by Sag A* and M87* is effectively
same for both Schwarzschild and Starobinsky-Bel-Robinson black hole.
Furthermore, we also calculated the angular diameter of the shadow in
Starobinsky-Bel-Robinson black hole and compared with the Schwarzschild black
hole. It is observed that the angular diameter of shadow for M87* and Sgr A* in
Starobinsky-Bel-Robinson black hole is smaller than the Schwarzschild black
hole. The calculated results satisfy the event horizon telescope observational
constraints. Finally, we have concluding remarks.Comment: 12 pages, 18 figures, accepted for publication in European Physical
Journal
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