Search results for "DEMOGRAPHY"
showing 10 items of 2125 documents
We made it to Germany … and now? Interdependent risks of vulnerability for refugees in a high-income country
2023
Refugees are perceived as a category of people that are ‘vulnerable’ per se. However, once they have arrived in (high-income) hosting countries and are supported by a welfare state, vulnerability needs to be rethought, as they face new challenges and potential sources of inequality. In this paper, we have measured vulnerability as the probability of experiencing jointly three interdependent risks: social isolation, financial worries and poor health. For this purpose, we estimated a trivariate logit model to evaluate how individual and household characteristics are associated with vulnerability and also made inferences regarding the residual association between pairs of risks, conditionally …
Prevalence and Time Trends in Myopia Among Children and Adolescents.
2020
Background Myopia (near-sightedness) is increasing worldwide, especially in Asia. The aim of this study was to describe trends in the prevalence of myopia in Germany. Methods We analyzed data from the German Health Interview and Examination Survey for Children and Adolescents (KiGGS; baseline survey 2003-2006, N = 17 640; wave 2, 2014-2017, N = 15 023). The presence of myopia was determined from a parent questionnaire and validated by the use of a visual aid. The population prevalence of myopia was calculated. Based on the KiGGS wave 2 data, potential risk factors for myopia were identified by means of logistic regression. Results The prevalence of myopia at the age of 0-17 years in Germany…
Fitness profile of young female volleyball players
2020
BACKGROUND: Factors that influence performance in volleyball, in terms of motor skills, refer to muscle power, speed and agility. This study aimed to examine the abilities and physical characteristics of female volleyball players in terms of age and player specialization. METHODS: A total of 35 subjects (junior and cadet age), participated in this study. Subjects were assessed for body height, mass, spike and block reach, and body composition. Vertical jump, standing broad jump, spike and block jump were tests used to measure leg power. The running speed was evaluated with a 20-m single-sprint effort. The change of direction speed was assessed with a T-test, the sprint 9-3-6-3-9 m forward-b…
The effect of birthplace on heat tolerance and mortality in Milan, Italy, 1980-1989
2006
The temperature–mortality relationship follows a well-known J-V shaped pattern with mortality excesses recorded at cold and hot temperatures, and minimum at some optimal value, referred as Minimum Mortality Temperature (MMT). As the MMT, which is used to measure the population heat-tolerance, is higher for people living in warmer places, it has been argued that populations will adapt to temperature changes. We tested this notion by taking advantage of a huge migratory flow that occurred in Italy during the 1950s, when a large number of unemployed people moved from the southern to the industrializing north-western regions. We have analyzed mortality–temperature relationships in Milan residen…
Copying the Mate Choice of Others? Observations On Female Black Grouse
1990
Abstract It has been suggested that the non-random mating often observed in lekking species is a consequence of either male-male competition or active female mate choice. Here we show that the highly skewed mating distributions observed in a black grouse lek in three years were indeed different from random expectations. We suggest that females copying the mate choice of others enhance this skew. Observations in favour of copying are: females pay multiple visits to the lek during several days; females arrive and move in bands which makes it possible to observe the visits to male territories and matings of other females; in the main lek in the study area, males often mated in sequence indica…
Moving from North to North: how are the students’ university flows?
2021
AbstractStudent mobility has been much commented upon and much studied. Student mobility has social, economic, and political consequences. This form of mobility is relevant, in Italy, in terms of south-north flows, while the mobility of northern students toward the South and Centre of Italy is negligible. To the best of our knowledge, a proper focus on the dynamics among northern regions has not yet been carried out. This study focuses on the interregional mobility of northern first-year students. To this end, we use a longitudinal dataset with students’ individual histories from 2008 to 2017, obtained from the cohort-based datasets collected using the Italian Ministry of University’s admin…
Sex differences in mate preferences across 45 countries: a large-scale replication
2020
Considerable research has examined human mate preferences across cultures, finding universal sex differences in preferences for attractiveness and resources as well as sources of systematic cultural variation. Two competing perspectives-an evolutionary psychological perspective and a biosocial role perspective-offer alternative explanations for these findings. However, the original data on which each perspective relies are decades old, and the literature is fraught with conflicting methods, analyses, results, and conclusions. Using a new 45-country sample (N = 14,399), we attempted to replicate classic studies and test both the evolutionary and biosocial role perspectives. Support for unive…
Breeding success and mate retention in birds: a meta-analysis
2002
Several hypotheses about the adaptive value of divorce in birds predict a positive effect of breeding success on mate retention. Although some studies have provided direct support for this prediction, others have failed to demonstrate any significant influence of breeding success on mate retention. To date, no one has investigated the overall empirical evidence for such a relationship. We used a meta-analysis of published results to investigate whether the rate of divorce between consecutive breeding seasons differed between successful and unsuccessful breeders among monogamous bird species. The analysis was based on 38 studies involving 35 different species. The mean weighted effect size, …
Evolution of avian clutch size along latitudinal gradients: do seasonality, nest predation or breeding season length matter?
2010
Birds display a latitudinal gradient in clutch size with smaller clutches in the tropics and larger in the temperate region. Three factors have been proposed to affect this pattern: seasonality of resources (SR), nest predation and length of the breeding season (LBS). Here, we test the importance of these factors by modelling clutch size evolution within bird populations under different environmental settings. We use an individual-based ecogenetic simulation model that combines principles from population ecology and life history theory. Results suggest that increasing SR from the tropics to the poles by itself or in combination with a decreasing predation rate and LBS can generate the latit…
Assortative mating and female clutch investment in black grouse
1999
Variation in female behaviour has only recently received attention in studies of sexual selection. It has been suggested that females may invest differentially in their offspring in relation to the quality of their mate. This may lead to females that mate with high-quality and/or attractive males laying larger clutches. Females may also differ in their ability to choose between males. For example, females in good physical condition may make better choices. If physical condition and clutch size are positively correlated, this hypothesis could also produce a relationship between male attractiveness and female clutch size. We found, in lekking black grouse, Tetrao tetrix, that females mated to…