A Derivation of Three-Dimensional Inertial Transformations

The derivation of the transformations between inertial frames made by Mansouri and Sexl is generalised to three dimensions for an arbitrary direction of the velocity. Assuming lenght contraction and time dilation to have their relativistic values, a set of transformations kinematically equivalent to special relativity is obtained. The ``clock hypothesis'' allows the derivation to be extended to accelerated systems. A theory of inertial transformations maintaining an absolute simultaneity is shown to be the only one logically consistent with accelerated movements. Algebraic properties of these transformations are discussed. Keywords: special relativity, synchronization, one-way velocity of light, ether, clock hypothesis.Comment: 16 pages (A5), Latex, one figure, to be published in Found. Phys. Lett. (1997

Change in quality of life among community-dwelling older adults: population-based longitudinal study.

This population-based study aimed to determine 5-year change in multidimensional QoL among community-dwelling older people, and to identify predictors of QoL change among demographic, socioeconomic, and health characteristics. Data of the 2011 and 2016 annual assessments of 1845 older men and women (age range 68-77 years) from the Lc65 + cohort study were used. QoL was assessed using a 28-item instrument yielding a QoL overall score and seven domain-specific QoL subscores. Additional ratings of QoL included a single item (excellent; very good; good; fair; poor), expected QoL in 1 year (better; worse; same as today), and retrospective assessment of QoL 5-year change (better; worse; same as 5 years ago). The predictors of 5-year change in the QoL score were assessed using linear regression, controlling for baseline QoL score. All prospective and retrospective indicators of QoL converged towards a slight deterioration over 5 years. QoL subscores significantly decreased in domains "Close entourage" (P = 0.004), "Social and cultural life" (P < 0.001), "Esteem and recognition" (P = 0.001), "Health and mobility" (P < 0.001), and "Autonomy" (P < 0.001), whereas "Material resources" (P = 0.345) and "Feeling of safety" (P = 0.380) remained stable. A stronger decrease in QoL was observed in the most vulnerable profiles at baseline in terms of demographic, socioeconomic, and health characteristics. Changes in depressive symptoms and in disability-either worsening or improving-predicted QoL change in the expected direction. Age-related decline in QoL may be limited through the prevention of disability and depressive symptoms, and more generally by devoting special attention to vulnerable profiles

Temporal changes in importance of quality of life domains: a longitudinal study in community-dwelling Swiss older people.

Population aging is a global phenomenon requiring interventions to improve quality of life (QoL), a subjective and dynamic concept. Such interventions should be based on QoL domains considered as important from older people's viewpoint. It is unclear whether and how much these domains may vary over time as people age. This study aims to assess the importance of QoL domains, their pattern and determinants of change among the non-institutionalized older population over a 5-year period. This longitudinal study included community-dwelling older adults (N = 1947, aged 68-77 years at baseline) from the Lausanne cohort 65+. In 2011 and 2016, participants rated the importance of 28 QoL items in seven domains. The difference between scores (0-100) of importance attributed to each QoL domain between two assessments was calculated and used as a dependent variable to assess the associations with covariates in multivariable analysis for each domain. Importance scores slightly but significantly decreased in five of the seven QoL domains. Despite the majority of participants did not modify their ranking of importance for each QoL domain between the two time points, the proportion of change was still substantial. Bivariate and multivariable analyses showed that education and to a lesser extent age, living arrangement and morbidity, were associated with decrease in the importance of specific QoL domains; characteristics indicating vulnerability (e.g., low education or morbidity) were associated with a decline in the importance. Although aging individuals modified the importance they give to the seven QoL domains, at population level, changes in opposite directions overall resulted in only small decline; importance seems less stable over time among individuals with vulnerable sociodemographic and health profiles

A rotating cavity for high-field angle-dependent microwave spectroscopy of low-dimensional conductors and magnets

The cavity perturbation technique is an extremely powerful method for measuring the electrodynamic response of a material in the millimeter- and sub-millimeter spectral range (10 GHz to 1 THz), particularly in the case of high-field/frequency magnetic resonance spectroscopy. However, the application of such techniques within the limited space of a high-field magnet presents significant technical challenges. We describe a 7.62 mm x 7.62 mm (diameter x length) rotating cylindrical cavity which overcomes these problems.Comment: 11 pages including 8 figure

Validity of the older people quality of life-7 domains (OQoL-7) scale.

The Older people Quality of Life-7 domains (OQoL-7) is a 28-item multidimensional questionnaire developed to measure community-dwelling older people's QoL. The OQoL-7 assesses both importance of and satisfaction in seven QoL domains (Material resources; Close entourage; Social and cultural life; Esteem and recognition; Health and mobility; Feeling of safety; and Autonomy). This study aimed to investigate concurrent and construct validity of the OQoL-7. A secondary aim was to compare different methods of weighting participants' ratings of satisfaction according to their individual ratings of importance, as compared to the OQoL-7 total score (unweighted). Data came from the first and second samples of the Lausanne cohort 65+ study, assessed at the same age of 72-77 years in 2011 (N = 1117) and 2016 (N = 1091), respectively. To assess concurrent validity, the OQoL-7 was compared to other measures of the same concept (single QoL item) or related concepts (self-rated health, SF-12). Construct validity was tested by comparing subscores in the seven QoL domains in the presence and absence of two stressful events during the preceding year (financial difficulties and relationship difficulties). The effect of importance weighting was assessed using moderated regression analysis. The OQoL-7 total score was significantly associated with the single QoL item (Spearman's rho 0.46), self-rated health (Spearman's rho 0.34), SF-12 physical (Spearman's rho 0.22) and mental (Spearman's rho 0.28) component scores. Large differences (Cohen's d > 0.8) were observed in the presence or absence of stressful events in the expected QoL domains: "Material resources" in the presence or absence of "Financial difficulties" (Cohen's d 1.34), and "Close entourage" in the presence or absence of "Relationship difficulties" (Cohen's d 0.84). Importance weighting resulted in a very small improvement in the prediction of the single QoL item (ΔR <sup>2</sup> 0.018). All results were highly consistent across 2011 and 2016 samples. The OQoL-7 showed adequate concurrent and construct validity in two samples of older people. In future studies, the decision to use weighted or unweighted scores will depend on the priority given to either optimizing the prediction of QoL or limiting the burden on respondents and the amount of missing data