General practitioner advice on physical activity: Analyses in a cohort of older primary health care patients (getABI)

<p>Abstract</p> <p>Background</p> <p>Although the benefits of physical activity for health and functioning are recognized to extend throughout life, the physical activity level of most older people is insufficient with respect to current guidelines. The primary health care setting may offer an opportunity to influence and to support older people to become physically active on a regular basis. Currently, there is a lack of data concerning general practitioner (GP) advice on physical activity in Germany. Therefore, the aim of this study was to evaluate the rate and characteristics of older patients receiving advice on physical activity from their GP.</p> <p>Methods</p> <p>This is a cross-sectional study using data collected at 7 years of follow-up of a prospective cohort study (German epidemiological trial on ankle brachial index, getABI). 6,880 unselected patients aged 65 years and above in the primary health care setting in Germany were followed up since October 2001. During the 7-year follow-up telephone interview, 1,937 patients were asked whether their GP had advised them to get regular physical activity within the preceding 12 months. The interview also included questions on socio-demographic and lifestyle variables, medical conditions, and physical activity. Logistic regression analysis (unadjusted and adjusted for all covariables) was used to examine factors associated with receiving advice. Analyses comprised only complete cases with regard to the analysed variables. Results are expressed as odds ratios (ORs) with 95% confidence intervals (95% CI).</p> <p>Results</p> <p>Of the 1,627 analysed patients (median age 77; range 72-93 years; 52.5% women), 534 (32.8%) stated that they had been advised to get regular physical activity. In the adjusted model, those more likely to receive GP advice on physical activity were men (OR [95% CI] 1.34 [1.06-1.70]), patients suffering from pain (1.43 [1.13-1.81]), coronary heart disease and/or myocardial infarction (1.56 [1.21-2.01]), diabetes mellitus (1.79 [1.39-2.30]) or arthritis (1.37 [1.08-1.73]), and patients taking a high (> 5) number of medications (1.41 [1.11-1.80]).</p> <p>Conclusions</p> <p>The study revealed a relatively low rate of older primary health care patients receiving GP advice on physical activity. GPs appeared to focus their advice on patients with chronic medical conditions. However, there are likely to be many more patients who would benefit from advice.</p

Field dependent soft mode frequency in Ba_xSr_1-xTiO₃ferroelectric perovskites

300-305An expression has been obtained for the soft mode frequency in BaxSr1-xTiO3 ferroelectric perovskites in the presence of external electric field, by using double time temperature dependent Green’s function technique. The mass and force constant change due to impurity atoms which are taken into account in the presence of higher order anharmonic and electric moment terms in the Silverman Joseph Hamiltonian. The soft mode frequency is obtained in the presence of both the electric field and impurity of Ba in an anharmonic SrTiO3 ferroelectric perovskites. The soft mode frequency decreases with increase of impurity concentration of Ba in pure SrTiO3 . The soft mode frequency also increases with increase of external electric field in BaXSr1-XTiO3 ferroelectric perovskites.</b

Field dependent dielectric behaviour of Ba₁_-xCa_xTiO₃ferroelectric perovskites

220-224The electric field dependence of complex dielectric constant of Ba1-xCaxTiO3 ferroelectric crystal in paraelectric phase has been studied by using the method of double times thermal Green’s function and Kubo formalism. A general expression is derived from the Silverman-Joseph Hamiltonian by taking into account the change of mass as well as harmonic force constant between impurity atom and host lattice atoms with fourth order phonon coordinates. The frequency, temperature and electric field dependent dielectric constant of Ba1-xCaxTiO3 crystal has been investigated. The dielectric constant increases with increase in temperature as well as with the applied electric field. The results are compared with the previous experimental and theoretical results

Sound attenuation in Ba₁_-xCa_xTiO₃ ferroelectric perovskites

398-402Theoretical expression of attenuation constant of anharmonic Ba1-xCaxTiO3 ferroelectric crystal in paraelectric phase using double times temperature dependent Green’s function technique, is derived. The variation of attenuation constant with frequency and temperature has been studied by considering third- and fourth-order anharmonic interactions, taking electric field as an important parameter. The mass and force constant change due to the presence of impurity atoms in Silverman-Joseph Hamiltonian augmented with higher order anharmonic terms. The effect of electric field, defect and anharmonicity on stabilization of the soft mode frequency has also been studied. The attenuation constant increases with increasing temperature and frequency in the presence of an electric field. In the vicinity of the Curie temperature, attenuation constant increases anomalously

Electric field dependent sound velocity change in Ba_1−xCa_xTiO₃ ferroelectric perovskites

132-136By using double time temperature dependent Green’s function technique, an expression for the sound velocity change in the mixed crystal perovskites (Ba1−xCaxTiO3) has been obtained with the help of the modified Silverman-Joseph Hamiltonian. Third- and fourth-order anharmonic and electric moment terms in the modified Hamiltonian for Ba1−xCaxTiO3 crystal perovskites have been considered. The effect of defect, electric field and anharmonic contributions on velocity change in Ba1−xCaxTiO3 for paraelectric phase has been studied. The presence of higher order anharmonicity and electric moment terms decreases the sound velocity. In the vicinity of the phase transition, it decreases as the consequence of the soft mode. It also varies with electric field and defect concentration in Ba1−xCaxTiO3