Towards understanding partial adaptation to the subterranean habitat in the European cave spider, Meta menardi: An ecocytological approach.

The European cave spider, Meta menardi, is a representative of the troglophiles, i.e. non-strictly subterranean organisms. Our aim was to interpret the cytological results from an ecological perspective, and provide a synthesis of the hitherto knowledge about M. menardi into a theory of key features marking it a troglophile. We studied ultrastructural changes of the midgut epithelial cells in individuals spending winter under natural conditions in caves, using light microscopy and TEM. The midgut diverticula epithelium consisted of secretory cells, digestive cells and adipocytes. During winter, gradual vacuolization of some digestive cells appeared, and some necrotic digestive cells and necrotic adipocytes appeared. This cytological information completes previous studies on M. menardi starved under controlled conditions in the laboratory. In experimental starvation and natural winter conditions, M. menardi gradually exploit reserve compounds from spherites, protein granules and through autophagy, and energy-supplying lipids and glycogen, as do many overwintering arthropods. We found no special cellular response to living in the habitat. Features that make it partly adapted to the subterranean habitat include starvation hardiness as a possible preadaptation, an extremely opportunistic diet, a partly reduced orb, tracking and capturing prey on bare walls and partly reduced tolerance to below-zero temperatures.

"In the mood for ageing": determinants of subjective well-being in older men and women of the population-based KORA-Age study.

BACKGROUND: To investigate risk factors associated with low subjective well-being (SWB) in men and women (≥65 years) separately with a special focus on emotional distress. METHODS: A cross-sectional analysis was conducted among 3602 participants (50.6% women) aged 65-90 years (mean age 72.8 years, SD ± 5.8) from the population-based KORA-Age study conducted in 2008/2009. SWB was assessed using the WHO-5 well-being index (score range: 0 to 100). SWB was dichotomized into "low" (score ≤ 50) and "high" (score > 50) SWB. The association between potential risk factors and SWB was assessed by logistic regressions analyses. Population-attributable risks (PARs) were calculated. RESULTS: Low SWB was significantly higher in women than in men (23.8% versus 18.2%; p < 0.0001). The logistic regressions analyses revealed low income, physical inactivity, multimorbidity, depression, anxiety and sleeping problems to be associated with low SWB in both sexes. Living alone increased the odds of having low SWB in women, but not in men. Depression and anxiety were the strongest risk factors of low SWB among men (depression: OR: 4.19, 95% CI: 1.33-13.17, p < 0.05; anxiety: 8.45, 5.14-13.87, p < 0.0001) and women (depression: 6.83, 2.49-18.75 p < 0.05; anxiety: 7.31, 5.14-10.39, p < 0.0001). In both sexes, anxiety had the highest population-attributable risk (men: 27%, women: 41%). CONCLUSION: Our results call out for an increased focus on mental health interventions among older adults, especially for women living alone. Further research is needed to understand the paradoxical pattern of discrepant subjective well-being versus objective health in age.

Malpighian Tubule Cells in Overwintering Cave Crickets Troglophilus cavicola (Kollar, 1833) and T. neglectus Krauss, 1879 (Rhaphidophoridae, Ensifera).

During winter, cave cricket larvae undergo dormancy in subterranean habitats; this dormancy is termed diapause in second year Troglophilus cavicola larvae because they mature during this time, and termed quiescence in T. neglectus, because they mature after dormancy. Here we used electron microscopy to analyze ultrastructural changes in the epithelial cells in the Malpighian tubules (MTs) of T. cavicola during diapause, in order to compare them with previous findings on T. neglectus. Moreover, the autophagosomes were studied with immunofluorescence microscopy in both species. Although the basic ultrastructure of the cells was similar, specific differences appeared during overwintering. During this natural starvation period, the nucleus, rER, the Golgi apparatus and mitochondria did not show structural changes, and the spherites were exploited. The abundances of autophagic structures in both species increased during overwintering. At the beginning of overwintering, in both species and sexes, the rates of cells with autophagic structures (phagophores, autophagosomes, autolysosomes and residual bodies) were low, while their rates increased gradually towards the end of overwintering. Between sexes, in T. cavicola significant differences were found in the autophagosome abundances in the middle and at the end, and in T. neglectus at the end of overwintering. Females showed higher rates of autophagic cells than males, and these were more abundant in T. cavicola. Thus, autophagic processes in the MT epithelial cells induced by starvation are mostly parallel in diapausing T. cavicola and quiescent T. neglectus, but more intensive in diapausing females.