BACKGROUND Age at menarche is known to be regulated by genetic and environmental factors. To date, no menarcheal data are available on North Korean women. In this cross-sectional survey, we investigated age at menarche and its possible influencing factors in North Korean refugees. METHODS Four hundred and eleven North Korean refugees were surveyed at a North Korean female refugee camp using a...

Most empirical tests of mediation utilize cross-sectional data despite the fact that mediation consists of causal processes that unfold over time. The authors considered the possibility that longitudinal mediation might occur under either of two different models of change: (a) an autoregressive model or (b) a random effects model. For both models, the authors demonstrated that cross-sectional a...

High energy hadronic total cross-section data are found to agree with the predictions of a QCD-string picture.

Legislation would be a Samuelsonian public good if the cost of creating legislation is not a function of the number of people covered by the legislation. A straighforward test of Samuelsonian publicness is undertaken by estimating the cost of producing legislation as a function of population and other variables, using cross-sectional data from the states of the United States for the years 1965,...

BACKGROUND In Switzerland, the mean age of GPs in 1993 was 46. In 2015, it had increased to 55, and GPs over 65 made up 15% of the workforce of the about 6000 GPs. As older, self-employed GPs retire, young doctors will be needed to fill their positions and eventually take over their practices. We set out to determine what kind of employment young GPs wanted, if they thought their preference wou...

Are happiness patterns structurally the same when comparing poor and rich countries? Using cross-sectional data from the SALDRU93 survey, we show that the relationships between subjective well-being and socioeconomic variables have a similar structure and is U-shaped in age in South Africa as in developed countries. Well-being rises with income. Unemployment is detrimental to reported well-bein...

OBJECTIVE To estimate daily fruit and vegetable intakes and to investigate socio-economic and behavioural differences in fruit and vegetable consumption among urban Moroccan women. DESIGN A cross-sectional survey. Fruit and vegetable intake was measured with a single 24 h recall. SETTINGS A representative population-based survey conducted in the area of Rabat-Salé. SUBJECTS Women (n 894) ...