Ventral-clap modes of hovering passerines.

Some small birds typically clap their wings ventrally, particularly during hovering. To investigate this phenomenon, we analyzed the kinematic motion and wake flow field of two passerine species that hover with the same flapping frequency. For these two birds, the ventral clap is classified as direct and cupping. Japanese White-eyes undertake a direct clap via their hand wings, whereas Gouldian Finches undertake a cupping clap with one wing overlaying the other. As a result of their morphological limitation, birds of both greater size and wing span cup their wings to increase the wing speed during a ventral clap because of the larger wing loading. This morphological limitation leads also to a structural discrepancy of the wake flow fields between these two passerine species. At the instant of clapping, the direct clap induces a downward air velocity 1.68 times and generates a weight-normalized lift force 1.14 times that for the cupping clap. The direct clap produces a small upward jet and a pair of counter-rotating vortices, both of which abate the transient lift at the instant of clapping, but they are not engendered by the cupping clap. The aerodynamic mechanisms generated with a ventral clap help the small birds to avoid abrupt body swinging at the instant of clapping so as to maintain their visual stability during hovering.

Increased medical costs in elders with the metabolic syndrome are most evident with hospitalization of men.

BACKGROUND: Little is known about health care costs associated with the metabolic syndrome (MetS). OBJECTIVE: We assessed annualized health care costs and health outcomes for both genders in different health care settings among representative Taiwanese elders. METHODS: The Nutrition and Health Survey in Taiwan (1999-2000) provided 1378 individuals aged 65 years or older with known MetS status. Nutrition and Health Survey in Taiwan files were linked to National Health Insurance records (1999-2006). Student t tests and multiple regression models were used to assess expenditures in total and in 6 services: inpatient, ambulatory care, dental care, traditional Chinese medicine, emergency care, and contracted pharmacy. The Cox model was used to assess gender effect on all-cause mortality and cardiovascular disease mortality, whereas logistic regression was used for that on cardiovascular disease hospitalization. The 5 MetS component costs were evaluated by multiple regressions. RESULTS: MetS affected 29% of men and 48% of women. After full adjustment, those with MetS had 1.30 (95% CI, 1.11-1.52), men had 1.43 (95% CI, 1.20-1.70), and women had 1.19 (95% CI, 0.93-1.52) times higher costs than those without MetS. Compared with no MetS, MetS costs were increased 2.94-fold for inpatient care (95% CI, 1.23-7.10) and 1.30-fold for ambulatory care for men (95% CI, 1.12-1.52), whereas ambulatory MetS costs were increased 1.28-fold for women (95% CI, 1.05-1.57). MetS was associated with higher risk of cardiovascular disease hospitalization in men (adjusted odds ratio, 1.76; 95% CI, 1.20-2.58) but not in women (adjusted odds ratio, 1.08; 95% CI, 0.67-1.75). Among those with MetS, all-cause and cardiovascular mortality were comparable between men and women. Of the MetS components, low HDL cholesterol had the greatest affect on costs, more so in men (2.23-fold) than women (1.58-fold). CONCLUSIONS: In people with MetS, service costs were greater overall, significantly for men, but not women, and these increased costs were evident for men who experienced hospitalization, but not women. At the same time, cardiovascular and all-cause mortalities were not significantly different by gender in regard to MetS in Taiwanese elders.