Association of sociodemographic and reproductive variables with menopause-specific quality of life using principal component analysis.

We aimed to determine whether sociodemographic and reproductive variables jointly or independently were associated with menopause-specific quality of life (MENQOL). A total of 250 Bengali-speaking Hindu women (peri- and postmenopausal) were recruited from West Bengal, India. Data on MENQOL (vasomotor, physical, psychosocial, sexual, and quality-of-life domains), sociodemographic, and reproductive variables were collected. Principal component (PC) analysis was used to identify PCs for sociodemographic and/or reproductive variables: PC1 (sociodemographic), PC2 (sociodemographic and reproductive), PC3, and PC4 (reproductive). PC scores were used in multiple regression analyses to determine associations with MENQOL. For perimenopausal women, PC1 and PC3 were inversely associated with the sexual domain; PC2 was positively associated with vasomotor, sexual domain, and quality of life; and PC3 was positively associated with the physical domain. For postmenopausal women, PC1 and PC3 were inversely associated with the sexual and psychosocial domains, respectively; PC2 was positively associated with the sexual domain and quality of life; and PC4 was positively associated with the psychosocial domain. The factors associated with MENQOL PCs were similar for perimenopausal and postmenopausal women. Health planners should consider early and midlife factors associated with MENQOL to improve women's midlife health.

Applicability of isothermal unrealistic two-parameter equations of state for solids.

The aim of the present study, an extension of a recent one (Bose Roy and Bose Roy 2005 J. Phys.: Condens. Matter 17 6193), is to assess and compare the curve-fitting utility of the isothermal unrealistic two-parameter equations of state for solids (EOS), proposed at different stages in the development of the EOS field, for the purposes of smoothing and interpolation of pressure-volume data, and extraction of accurate values of the isothermal bulk modulus and its pressure derivative. To this end, 21 such EOSs are considered, formulated by/labelled as Born-Mie (1920), Born-Mayer (1932), Bardeen (1938), Slater-Morse (1939), Birch-Murnaghan (1947), Pack-Evans-James (1948), Lagrangian (1951), Davydov (1956), Davis and Gordon (1967), Onat and Vaisnys (1967), Grover-Getting-Kennedy (1973), Brennan-Stacey (1979), Walzer-Ullmann-Pan'kov (1979), Rydberg (1981), Dodson (1987), Holzapfel (1991), Parsafar-Mason (1994), Shanker-Kushwah-Kumar (1997), Poirier-Tarantola (1998), Deng-Yan (2002) and Kun-Loa-Syassen (2003). Furthermore, all these EOSs are compared with our three-parameter EOS, as well as its two-parameter counterpart proposed in this work. We have applied all the EOS models, with no constraint on the parameters, to the accurate and model-independent isotherms of nine solids. The applicability has been assessed in terms of an unbiased composite test, comprising fitting accuracy, agreement of the fit parameters with experiment, stability of the fit parameters with variation in the compression/pressure ranges and on the basis of the number of wiggles of the data deviation curves about the fit parameters. Furthermore, a rigorous method is devised to scale the relative adequacy of the EOSs with respect to the test parameters. A number of remarkable findings emerge from the present study. Surprisingly, both the old EOSs, the Born-Mie and the Pack-Evans-James, are significantly better in their curve-fitting capability than the Birch-Murnaghan EOS which has been widely used and continues to be used for curve-fitting purposes as a standard EOS in the literature. The Born-Mayer as well as the Walzer-Ullmann-Pan'kov models also fit isotherms better than the Birch. The performance of the EOS based on the Rydberg potential-that has been rediscovered by Rose et al (1984 Phys. Rev. B 29 2963), and strongly promoted by Vinet et al (1989 J. Phys.: Condens. Matter 1 1941) as the so-called universal equation of state, and is currently used as a standard EOS along with that of the Birch-is very poor, on a comparative scale. Furthermore, the curve-fitting capability of our original three-parameter EOS, and more importantly its two-parameter counterpart, is superior to all the isothermal unrealistic two-parameter EOSs so far proposed in the literature.