Iterative algorithm versus analytic solutions of the parametrically driven dissipative quantum harmonic oscillator

We consider the Brownian motion of a quantum mechanical particle in a one-dimensional parabolic potential with periodically modulated curvature under the influence of a thermal heat bath. Analytic expressions for the time-dependent position and momentum variances are compared with results of an iterative algorithm, the so-called quasiadiabatic propagator path integral algorithm (QUAPI). We obtain good agreement over an extended range of parameters for this spatially continuous quantum system. These findings indicate the reliability of the algorithm also in cases for which analytic results may not be available a priori.Comment: 15 pages including 11 figures, one reference added, minor typos correcte

Serological identification of virus in watermelon production fields in the Tocantins State.

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Prevalence of polypharmacy in community-dwelling older adults from seven centres in five European countries : A cross-sectional study of DO-HEALTH

Objective To investigate the prevalence of polypharmacy and characteristics associated with polypharmacy in older adults from seven European cities. Design Cross-sectional study of baseline data from DO-HEALTH. Setting and participants DO-HEALTH enrolled 2157 community-dwelling adults age 70 and older from seven centres in Europe. Participants were excluded if they had major health problems or Mini-Mental State Examination Score <24 at baseline. Primary outcome measures Extensive information on prescription and over-the-counter medications were recorded. Polypharmacy was defined as the concomitant use of five or more medications, excluding vitamins or dietary supplements. Bivariate and multivariable logistic regression was used to test the association of sociodemographic factors (age, sex, years of education, living situation and city) and health-related indicators (number of comorbidities, cognitive function, frailty status, body mass index (BMI), prior fall, self-rated health and smoking status) with polypharmacy. Results 27.2% of participants reported polypharmacy ranging from 16.4% in Geneva to 60.8% in Coimbra. In the multivariable logistic regression analyses, older age (OR 1.07; 95% CI 1.04 to 1.10), greater BMI (OR 1.09; 95% CI 1.06 to 1.12) and increased number of comorbidities (OR 2.13; 95% CI 1.92 to 2.36) were associated with polypharmacy. Women were less likely to report polypharmacy than men (OR 0.65; 95% CI 0.51 to 0.84). In comparison to participants from Zurich, participants from Coimbra were more likely to report polypharmacy (OR 2.36; 95% CI 1.56 to 3.55), while participants from Geneva or Toulouse were less likely to report polypharmacy ((OR 0.36; 95% CI 0.22 to 0.59 and OR 0.64; 95% CI 0.42 to 0.96), respectively). Living situation, smoking status, years of education, prior fall, cognitive function, self-rated health and frailty status were not significantly associated with polypharmacy. Conclusion Polypharmacy is common among relatively healthy older adults, with moderate variability across seven European cities. Independent of several confounders, being a woman, older age, greater BMI and greater number of comorbidities were associated with increased odds for polypharmacy. Trial registration number NCT01745263

Prevalence of polypharmacy in community-dwelling older adults from seven centres in five European countries: a cross-sectional study of DO-HEALTH.

OBJECTIVE To investigate the prevalence of polypharmacy and characteristics associated with polypharmacy in older adults from seven European cities. DESIGN Cross-sectional study of baseline data from DO-HEALTH. SETTING AND PARTICIPANTS DO-HEALTH enrolled 2157 community-dwelling adults age 70 and older from seven centres in Europe. Participants were excluded if they had major health problems or Mini-Mental State Examination Score <24 at baseline. PRIMARY OUTCOME MEASURES Extensive information on prescription and over-the-counter medications were recorded. Polypharmacy was defined as the concomitant use of five or more medications, excluding vitamins or dietary supplements. Bivariate and multivariable logistic regression was used to test the association of sociodemographic factors (age, sex, years of education, living situation and city) and health-related indicators (number of comorbidities, cognitive function, frailty status, body mass index (BMI), prior fall, self-rated health and smoking status) with polypharmacy. RESULTS 27.2% of participants reported polypharmacy ranging from 16.4% in Geneva to 60.8% in Coimbra. In the multivariable logistic regression analyses, older age (OR 1.07; 95% CI 1.04 to 1.10), greater BMI (OR 1.09; 95% CI 1.06 to 1.12) and increased number of comorbidities (OR 2.13; 95% CI 1.92 to 2.36) were associated with polypharmacy. Women were less likely to report polypharmacy than men (OR 0.65; 95% CI 0.51 to 0.84). In comparison to participants from Zurich, participants from Coimbra were more likely to report polypharmacy (OR 2.36; 95% CI 1.56 to 3.55), while participants from Geneva or Toulouse were less likely to report polypharmacy ((OR 0.36; 95% CI 0.22 to 0.59 and OR 0.64; 95% CI 0.42 to 0.96), respectively). Living situation, smoking status, years of education, prior fall, cognitive function, self-rated health and frailty status were not significantly associated with polypharmacy. CONCLUSION Polypharmacy is common among relatively healthy older adults, with moderate variability across seven European cities. Independent of several confounders, being a woman, older age, greater BMI and greater number of comorbidities were associated with increased odds for polypharmacy. TRIAL REGISTRATION NUMBER NCT01745263

Bosonic representation of one-dimensional Heisenberg ferrimagnets

The energy structure and the thermodynamics of ferrimagnetic Heisenberg chains of alternating spins S and s are described in terms of the Schwinger bosons and modified spin waves. In the Schwinger representation, we average the local constraints on the bosons and diagonalize the Hamiltonian at the Hartree-Fock level. In the Holstein-Primakoff representation, we optimize the free energy in two different ways introducing an additional constraint on the staggered magnetization. A new modified spin-wave scheme, which employs a Lagrange multiplier keeping the native energy structure free from temperature and thus differs from the original Takahashi Scheme, is particularly stressed as an excellent language to interpret one-dimensional quantum ferrimagnetism. Other types of one-dimensional ferrimagnets and the antiferromagnetic limit S=s are also mentioned.Comment: to be published in Phys. Rev. B 69, No. 6, 0644XX (2004