3,047 research outputs found
The Effects of Negative Body Image and Self-assessed Health on Health Behaviors in Adults
Body image (BI) is a complex concept that seems to be related to self-assessed health (SAH), in other words, how an individual perceives his or her health. Negative BI does seem to influence adaptive and maladaptive health behaviors. For example, women with negative BI are more likely to smoke cigarettes and have more difficulty with smoking cessation than their counterparts with less negative BI. Previous studies have explored the relationship between select variables, and the samples have consisted of mostly adolescents and European samples. The current study aimed to determine if a relationship exists between these variables and to examine if negative BI and SAH predict health behaviors. Currently, the literature examining whether BI and SAH predict health behaviors is sparse. One hundred eighty-nine participants (155 female, 33 male) were recruited online and completed the study. Results demonstrated a significant negative relationship between BI and SAH and no significant relationship between BI and health behaviors. Additional findings included gender having a statistically significant effect on BI, but not on SAH and health behaviors. SAH was also found to be a significant predictor of health behaviors, unlike BI, which was not found to be a significant predictor variable. Lastly, BI and SAH were not found to be significant predictors of genderspecific medical nonadherence. Research and clinical implications of the findings and future directions are discussed
Effects of lattice distortion and Jahn–Teller coupling on the magnetoresistance of La0.7Ca0.3MnO3 and La0.5Ca0.5CoO3 epitaxial films
Studies of La0.7Ca0.3MnO3 epitaxial films on substrates with a range of lattice constants reveal two dominant contributions to the occurrence of colossal negative magnetoresistance (CMR) in these manganites: at high temperatures (T → TC, TC being the Curie temperature), the magnetotransport properties are predominantly determined by the conduction of lattice polarons, while at low temperatures (T ≪ TC/, the residual negative magnetoresistance is correlated with the substrate-induced lattice distortion which incurs excess magnetic domain wall scattering. The importance of lattice polaron conduction associated with the presence of Jahn–Teller coupling in the manganites is further verified by comparing the manganites with epitaxial films of another ferromagnetic perovskite, La0.5Ca0.5CoO3. Regardless of the differences in the substrate-induced lattice distortion, the cobaltite films exhibit much smaller negative magnetoresistance, which may be attributed to the absence of Jahn–Teller coupling and the high electron mobility that prevents the formation of lattice polarons. We therefore suggest that lattice polaron conduction associated with the Jahn–Teller coupling is essential for the occurrence of CMR, and that lattice distortion further enhances the CMR effects in the manganites
Heavy fermion fluid in high magnetic fields: an infrared study of CeRuSb
We report a comprehensive infrared magneto-spectroscopy study of
CeRuSb compound revealing quasiparticles with heavy effective mass
m, with a detailed analysis of optical constants in fields up to 17 T. We
find that the applied magnetic field strongly affects the low energy
excitations in the system. In particular, the magnitude of m 70
m (m is the quasiparticle band mass) at 10 K is suppressed by as much
as 25 % at 17 T. This effect is in quantitative agreement with the mean-field
solution of the periodic Anderson model augmented with a Zeeman term
Site dilution of quantum spins in the honeycomb lattice
We discuss the effect of site dilution on both the magnetization and the
density of states of quantum spins in the honeycomb lattice, described by the
antiferromagnetic Heisenberg spin-S model. For this purpose a real-space
Bogoliubov-Valatin transformation is used. In this work we show that for the
S>1/2 the system can be analyzed in terms of linear spin wave theory. For spin
S=1/2, however, the linear spin wave approximation breaks down. In this case,
we have studied the effect of dilution on the staggered magnetization using the
Stochastic Series Expansion Monte Carlo method. Two main results are to be
stressed from the Monte Carlo method: (i) a better value for the staggered
magnetization of the undiluted system, m=0.2677(6); (ii) a finite value of the
staggered magnetization of the percolating cluster at the classical percolation
threshold, showing that there is no quantum critical transition driven by
dilution in the Heisenberg model. In the solution of the problem using linear
the spin wave method we pay special attention to the presence of zero energy
modes. Using a combination of linear spin wave analysis and the recursion
method we were able to obtain the thermodynamic limit behavior of the density
of states for both the square and the honeycomb lattices. We have used both the
staggered magnetization and the density of states to analyze neutron scattering
experiments and Neel temperature measurements on quasi-two- -dimensional
honeycomb systems. Our results are in quantitative agreement with experimental
results on Mn_pZn_{1-p}PS_3 and on the Ba(Ni_pMg_{1-p})_2V_2O_8.Comment: 21 pages (REVTEX), 16 figure
Chiral magnetization textures stabilized by the Dzyaloshinskii-Moriya interaction during spin-orbit torque switching
We study the effect of the Dzyaloshinskii-Moriya interaction (DMI) on
current-induced magnetic switching of a perpendicularly magnetized
heavy-metal/ferromagnet/oxide trilayer both experimentally and through
micromagnetic simulations. We report the generation of stable helical
magnetization stripes for a sufficiently large DMI strength in the switching
region, giving rise to intermediate states in the magnetization confirming the
essential role of the DMI on switching processes. We compare the simulation and
experimental results to a macrospin model, showing the need for a micromagnetic
approach. The influence of the temperature on the switching is also discussed.Comment: Includes corrected acknowledgements and clarification of simulation
parameter
Ageing as developmental decay: insights from p16(INK4a.)
The p16(INK4a) cell cycle regulator is one of the best ageing biomarkers because it is suppressed in early embryogenesis and progressively induced during ageing. p16(INK4a) plays a crucial role in key cell fate decisions which contribute to ageing, such as cellular senescence and stem cell dynamics. Detailed examination of the pathways regulating p16(INK4a) expression has revealed an overlap with those regulating early development. We present the hypothesis that ageing might be primarily driven by gradual functional decay of developmental pathways. To support this, we summarise the role of p16(INK4a) in ageing and our current knowledge on p16(INK4a) regulation. The developmental decay hypothesis implies that the much-evidenced damage associated with all aspects of ageing might be secondary to such decay
Comorbidities of Idiopathic Thrombocytopenic Purpura: A Population-Based Study
A person experiencing more than one medical condition may have ambiguous clinical
presentation. ITP is a serious autoimmune disease with little epidemiological evidence on its
burden, risk factors, and comorbidities. Using the United Kingdom
general practice research database, we conducted a 14 years population-based
case control-type study to explore medical conditions more likely to cooccur with
ITP and their temporal relationship in association with ITP. ITP patients were matched
to non-ITP on practice, age, gender, and follow-up period. Potential comorbidities
were represented by patients' medical information at the preferred
term level of the MedDRA international classification. As well as death
(OR = 60.0; 95% CI [4.47–806.0]) and known clinical signs and symptoms
of ITP, ITP is associated with considerable number of medical conditions.
The association between ITP and some of these conditions is apparent both
before and after ITP diagnosis. Specific targeted studies can now be setup to reexamine
observed associations
Inequalities in time from stopping paid work to death: findings from the ONS Longitudinal Study, 2001 to 2011
Background: United Kingdom State pension eligibility ages are linked to average life expectancy, which ignores wide socioeconomic disparities in health, and overall, life expectancy.
Objectives: Investigate whether there are occupational social class differences in the amount of time older adults live after they stop work, and how much of these differences are due to health.
Methods: Participants were 76 485 members of the ONS Longitudinal Study (LS), who were 50-75y at the 2001 census and had stopped work by the 2011 census. Over 10 years of follow-up, we used censored linear regression to estimate mean differences in years between stopping work and death by occupational social class.
Results: After adjustment for age, both social class and health were independent predictors of post-work duration [Mean difference (95% CI): Unskilled class vs Professional 2.7yrs (2.4, 3.1); not good vs good health 2.4yrs (1.9; 2.9)], with LS members in the three manual classes experiencing ~1 additional year of post-work duration than professional workers (interaction p-values all <0.001). Further adjustment for gender and educational qualifications reduced, but did not eliminate social class and post-work duration associations. We estimate the difference in post-work years between professional classes in good health and unskilled workers not in good health as 5.1 years for women (21.0 vs 26.1) and 5.5 years for men (19.5 vs 25.0).
Conclusions: Lower social class groups are negatively affected by uniform state pension ages, because they are more likely to stop work at younger ages due to health reasons
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