History, epidemiology and regional diversities of urolithiasis

Archeological findings give profound evidence that humans have suffered from kidney and bladder stones for centuries. Bladder stones were more prevalent during older ages, but kidney stones became more prevalent during the past 100 years, at least in the more developed countries. Also, treatment options and conservative measures, as well as ‘surgical’ interventions have also been known for a long time. Our current preventive measures are definitively comparable to those of our predecessors. Stone removal, first lithotomy for bladder stones, followed by transurethral methods, was definitively painful and had severe side effects. Then, as now, the incidence of urolithiasis in a given population was dependent on the geographic area, racial distribution, socio-economic status and dietary habits. Changes in the latter factors during the past decades have affected the incidence and also the site and chemical composition of calculi, with calcium oxalate stones being now the most prevalent. Major differences in frequency of other constituents, particularly uric acid and struvite, reflect eating habits and infection risk factors specific to certain populations. Extensive epidemiological observations have emphasized the importance of nutritional factors in the pathogenesis of urolithiasis, and specific dietary advice is, nowadays, often the most appropriate for prevention and treatment of urolithiasis

Dynamics of Disks and Warps

This chapter reviews theoretical work on the stellar dynamics of galaxy disks. All the known collective global instabilities are identified, and their mechanisms described in terms of local wave mechanics. A detailed discussion of warps and other bending waves is also given. The structure of bars in galaxies, and their effect on galaxy evolution, is now reasonably well understood, but there is still no convincing explanation for their origin and frequency. Spiral patterns have long presented a special challenge, and ideas and recent developments are reviewed. Other topics include scattering of disk stars and the survival of thin disks.Comment: Chapter accepted to appear in Planets, Stars and Stellar Systems, vol 5, ed G. Gilmore. 32 pages, 17 figures. Includes minor corrections made in proofs. Uses emulateapj.st

Prospective associations of social isolation and loneliness with poor sleep quality in older adults

PURPOSE: There is evidence for negative associations between social isolation and loneliness and sleep quality in older adults. However, it is unclear to what extent these two factors independently affect sleep quality. This study examined the simultaneous associations of social isolation and loneliness with sleep quality in a longitudinal study of older adults. METHODS: Data were analyzed from the Social Environment and Biomarkers of Aging Study in Taiwan collected in 2000 and 2006, involving a cohort of 639 participants (mean age = 66.14, SD 7.26). Poisson regression models were conducted to examine the association of social isolation and/or loneliness with sleep quality at follow-up after adjusting for multiple confounding variables. RESULTS: Univariate analysis showed that sleep quality was inversely associated with both social isolation and loneliness. After demographic, health, cognitive factors, and depressive symptoms were controlled in multivariable analysis, social isolation at the baseline still predicted poor sleep quality 6 years later (incident rate ratio, IRR 1.14; 95% CI 1.04-1.24; p < 0.01), while the association between loneliness and sleep quality was no longer significant (IRR 1.08; 95% CI 0.94-1.23; p = 0.27). The results were unchanged when participants who had poor sleep quality at the baseline were excluded from the analysis. CONCLUSIONS: These findings confirm an adverse effect of social isolation on the sleep quality of older adults, but indicate that this effect is independent of loneliness. Social isolation and loneliness seem to have distinct pathways in affecting the sleep quality of older adults