262 research outputs found
Awareness of COPD in a High Risk Indian Population: A Cross Sectional Study
INTRODUCTION: Chronic obstructive pulmonary disease (COPD) has a major impact on the health of an Individual and is a burden to the society.AIM: To assess the attitudes towards COPD among smokers who are at a high risk of developing the disease in Ranga Reddy District, Telangana, IndiaMATERIALS AND METHODS: This study was a cross-sectional survey conducted among five dental camps conducted in district of Ranga Reddy in current smokers (both bidi and cigarette) aged 45 years and older with a history of at least 10 pack(for cigarette)/bundle(for bidi)-years of smoking. The subjects were distributed over four age groups, which were 45‒49 years, 50‒59 years, 60‒69 years, and >70 Years. Data was collected through a pre-validated, close ended structured questionnaire divided into four parts regarding the participant’s demographics, current health status, symptoms, awareness of COPD, attitudes towards COPD and willingness to quit smoking. Data was analysed using SPSS version 21.0.RESULTS: Of a total of 426 subjects, (male predominance 94.2%.) , people belonging to the age groups of 40-49 years and >70 years reported themselves being in “Good health”. Only 3.5% reported having to know COPD as a respiratory disease as compared to 24.9% of the population who recognised lung cancer as the most common respiratory disease. 46.2% subjects acknowledged that cough was a symptom most commonly associated with COPD. Only a few portion of the subjects (1.8%) were willing to visit a doctor for diagnosis of COPD. Willingness to quit smoking among the respondents was seen in only 24.7% of the population and 14.5% could not decide about the same.CONCLUSION: Efforts are needed to be directed towards proper counselling and education of the people of Ranga Reddy district to prevent them from the ill-effects of Tobacco and its related diseases, especially COPD
All unitary cubic curvature gravities in D dimensions
We construct all the unitary cubic curvature gravity theories built on the
contractions of the Riemann tensor in D -dimensional (anti)-de Sitter
spacetimes. Our construction is based on finding the equivalent quadratic
action for the general cubic curvature theory and imposing ghost and tachyon
freedom, which greatly simplifies the highly complicated problem of finding the
propagator of cubic curvature theories in constant curvature backgrounds. To
carry out the procedure we have also classified all the unitary quadratic
models. We use our general results to study the recently found cubic curvature
theories using different techniques and the string generated cubic curvature
gravity model. We also study the scattering in critical gravity and give its
cubic curvature extensions.Comment: 24 pages, 1 figure, v2: A subsection on cubic curvature extensions of
critical gravity is added, v3: The part regarding critical gravity is
revised. Version to appear in Class. Quant. Gra
Temperature dependence of electrical properties in In/Cu2ZnSnTe4/Si/Ag diodes
WOS: 000458625200001Cu2ZnSnTe4 (CZTTe) thin films with In metal contact were deposited by thermal evaporation on monocrystalline n-type Si wafers with Ag ohmic contact to investigate the device characteristics of an In/CZTTe/Si/Ag diode. The variation in electrical characteristics of the diode was analysed by carrying out current-voltage (I-V) measurements in the temperature range of 220-360 K. The forward bias I-V behaviour was modelled according to the thermionic emission (TE) theory to obtain main diode parameters. In addition, the experimental data were detailed by taking into account the presence of an interfacial layer and possible dominant current transport mechanisms were studied under analysis of ideality factor, n. Strong effects of temperature were observed on zero-bias barrier height (Phi(B0)) and n values due to barrier height inhomogeneity at the interface. The anomaly observed in the analysis of TE was modelled by Gaussian distribution (GD) of barrier heights with 0.844 eV mean barrier height and 0.132 V standard deviation. According to the Tung's theoretical approach, a linear correlation between Phi(B0) and n cannot be satisfied, and thus the modified Richardson plot was used to determine Richardson constant (A*). As a result, A* was calculated approximately as 120.6 A cm(-2) K-2 very close to the theoretical value for n-Si. In addition, the effects of series resistance (R-s) by estimating from Cheng's function and density of surface states (N-ss) by taking the bias dependence of effective barrier height, were discussed
Hamiltonian analysis of BHT massive gravity
We study the Hamiltonian structure of the Bergshoeff-Hohm-Townsend (BHT)
massive gravity with a cosmological constant. In the space of coupling
constants , our canonical analysis reveals the special role of
the condition . In this sector, the dimension of the
physical phase space is found to be , which corresponds to two
Lagrangian degree of freedom. When applied to the AdS asymptotic region, the
canonical approach yields the conserved charges of the BTZ black hole, and
central charges of the asymptotic symmetry algebra.Comment: LATEX, 21 pages; v2: minor correction
Massive Gravity Theories and limits of Ghost-free Bigravity models
We construct a class of theories which extend New Massive Gravity to higher
orders in curvature in any dimension. The lagrangians arise as limits of a new
class of bimetric theories of Lovelock gravity, which are unitary theories free
from the Boulware-Deser ghost. These Lovelock bigravity models represent the
most general non-chiral ghost-free theories of an interacting massless and
massive spin-two field in any dimension. The scaling limit is taken in such a
way that unitarity is explicitly broken, but the Boulware-Deser ghost remains
absent. This automatically implies the existence of a holographic -theorem
for these theories. We also show that the Born-Infeld extension of New Massive
Gravity falls into our class of models demonstrating that this theory is also
free of the Boulware-Deser ghost. These results extend existing connections
between New Massive Gravity, bigravity theories, Galileon theories and
holographic -theorems.Comment: 11+5 page
Extra gauge symmetries in BHT gravity
We study the canonical structure of the Bergshoeff-Hohm-Townsend massive
gravity, linearized around a maximally symmetric background. At the critical
point in the space of parameters, defined by , we discover an
extra gauge symmetry, which reflects the existence of the partially massless
mode. The number of the Lagrangian degrees of freedom is found to be 1. We show
that the canonical structure of the theory at the critical point is unstable
under linearization.Comment: LATEX, 12 page
Generalised massive gravity one-loop partition function and AdS/(L)CFT
The graviton 1-loop partition function is calculated for Euclidean
generalised massive gravity (GMG) using AdS heat kernel techniques. We find
that the results fit perfectly into the AdS/(L)CFT picture. Conformal
Chern-Simons gravity, a singular limit of GMG, leads to an additional
contribution in the 1-loop determinant from the conformal ghost. We show that
this contribution has a nice interpretation on the conformal field theory side
in terms of a semi-classical null vector at level two descending from a primary
with conformal weights (3/2,-1/2).Comment: 25 p., 2 jpg figs, v2: added 6 lines of clarifying text after Eq.
(2.38
Nonlinear Dynamics of Parity-Even Tricritical Gravity in Three and Four Dimensions
Recently proposed "multicritical" higher-derivative gravities in Anti de
Sitter space carry logarithmic representations of the Anti de Sitter isometry
group. While generically non-unitary already at the quadratic, free-theory
level, in special cases these theories admit a unitary subspace. The simplest
example of such behavior is "tricritical" gravity. In this paper, we extend the
study of parity-even tricritical gravity in d = 3, 4 to the first nonlinear
order. We show that the would-be unitary subspace suffers from a linearization
instability and is absent in the full non-linear theory.Comment: 22 pages; v2: references added, published versio
Tricritical gravity waves in the four-dimensional generalized massive gravity
We construct a generalized massive gravity by combining quadratic curvature
gravity with the Chern-Simons term in four dimensions. This may be a candidate
for the parity-odd tricritical gravity theory. Considering the AdS vacuum
solution, we derive the linearized Einstein equation, which is not similar to
that of the three dimensional (3D) generalized massive gravity. When a
perturbed metric tensor is chosen to be the Kerr-Schild form, the linearized
equation reduces to a single massive scalar equation. At the tricritical points
where two masses are equal to -1 and 2, we obtain a log-square wave solution to
the massive scalar equation. This is compared to the 3D tricritical generalized
massive gravity whose dual is a rank-3 logarithmic conformal field theory.Comment: 17 pages, 1 figure, version to appear in EPJ
Holographic two-point functions for 4d log-gravity
We compute holographic one- and two-point functions of critical
higher-curvature gravity in four dimensions. The two most important operators
are the stress tensor and its logarithmic partner, sourced by ordinary massless
and by logarithmic non-normalisable gravitons, respectively. In addition, the
logarithmic gravitons source two ordinary operators, one with spin-one and one
with spin-zero. The one-point function of the stress tensor vanishes for all
Einstein solutions, but has a non-zero contribution from logarithmic gravitons.
The two-point functions of all operators match the expectations from a
three-dimensional logarithmic conformal field theory.Comment: 35 pages; v2: typos corrected, added reference; v3: shorter
introduction, minor changes in the text in section 3, added reference;
published versio
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