Mathematical modeling of the radial profile of basilar membrane vibrations in the inner ear

Motivated by recent experimental results we seek an explanation of asymmetry in the radial profile of basilar membrane vibrations in the inner ear. We study a sequence of one-dimensional beam models which take into account variations in the bending stiffness of the basilar membrane as well as the potential presence of structural hinges. Our results suggest that the main cause of asymmetry is likely to be differences between the boundary conditions at the two extremes of the basilar membrane's width. This has fundamental implications for more detailed numerical simulations of the entire cochle

A semi-analytical model for the wrinkling of laminates during consolidation over a corner radius

9 Pages, 8 figures, submitted to Composite Science and Technology May 2013If carbon fibre layers are prevented from slipping over one another as they consolidate onto a non-trivial geometry, they can be particularly susceptible to wrinkling/buckling instabilities. A one dimensional model for wrinkling during consolidation over an external radius is presented. Critical conditions for the appearance of wrinkles provide possible manufacturing and design strategies to minimise wrinkling. Numerical results for the unstable post buckling paths show localized buckling behaviour which demonstrates qualitative agreement with micrographs of wrinkles.The authors would like to acknowledge GKN Aerospace and TSB for supporting this work under the grant TSB:1000774. We are grateful to Ian Lang, Christopher Jones and Richard Newley, from GKN Aerospace, for many useful discussions

Domestic Workload and Multiple Roles. Epidemiological findings on health and sickness absence in women

Aim: The objective of this thesis was to analyse the importance of specific exposures in women’s lives to health and sickness absence; more precisely to study the association between domestic work, multiple roles and the experience of being sick-listed, and self-rated health, psychiatric disorders and sickness absence. Method: The thesis was based on two datasets. ‘Women’s health and living conditions’ (WHL) is a cross-sectional study on 1 417 employed women aged 17 to 64 years old. Data was collected with a questionnaire, and register and employee data on sickness absence. ‘Women and alcohol in Göteborg’ (WAG) is a prospective cohort study on 1 799 women in eight age cohorts born from 1925 to 1980. Data was collected with a screening questionnaire, interviews and register-based sickness absence. Several aspects of domestic work, multiple roles and experience of sickness absence were analysed in relation to self-rated health (SF-36), psychiatric disorders (DSM-III and IV) and sickness absence. The study on multiple roles emanated from the role strain and role enhancement hypotheses and roles were analysed as single roles and as combinations of roles. Changes in self-rated physical health were assessed in relation to experience of sickness absence over five year. Cross-sectional and longitudinal analyses were conducted using multivariate regressions analyses. Results: Domestic job strain and a lack of domestic work equity and marital satisfaction were associated with lower self-rated health particularly vitality and mental health. The former was not associated to sickness absence, but the latter was. Women with domestic workload due to children and adults with special needs had higher odds for medium-long sick-leave spells, while parental responsibility gave lower odds for any sick-leave spell. Occupation was related to lower odds for poor self-rated physical health and sickness absence, while the parental role was associated with higher odds for sickness absence. Compared with women who had all three roles women with occupation and partner role had lower odds for negative health outcomes. Support was found for the role strain hypothesis in the cross-sectional analyses of role combinations while neither of the hypotheses was supported in the five year follow up. A lower proportion of those who had experience of being sick-listed reported good health at both baseline and follow up. Women with psychiatric disorders had higher odds for a change from poor to good self-rated physical health over the five years if they had been sick-listed. Conclusion: Domestic workload was associated to health and sickness absence in women, but there were inconsistencies in the findings on children and being a parent and on multiple roles. From a public health perspective, deeper knowledge on the importance of women’s engagement domestic work and its different dimensions is important for promoting women’s health. A multidimensional assessment of domestic work is important and the content and complexity of domestic work and of different roles needs to be further explored in relation to health and sickness absence in women

What a difference a term makes:the effect of educational attainment on marital outcomes in the UK

Abstract In the past, students in England and Wales born within the first 5 monthsof the academic year could leave school one term earlier than those born later inthe year. Focusing on women, those who were required to stay on an extra termmore frequently hold some academic qualification. Using having been required tostay on as an exogenous factor affecting academic attainment, we find that holding alow-level academic qualification has no effect on the probability of being currentlymarried for women aged 25 or above, but increases the probability of the husbandholding some academic qualification and being economically active.33 Halama

Effects of food type, feeding frequency, and temperature on juvenile survival and growth of Marisa cornuarietis (Mollusca: Gastropoda)

The present experiments are part of a larger study designed to investigate the influence of husbandry parameters on the life history of the ramshorn snail, Marisa cornuarietis, in order to identify suitable husbandry conditions for maintaining multi-generation populations in the laboratory for use in ecotoxicological testing. In this paper we focus on the effects of a combination of food types and feeding frequencies (i.e., the frequency with which the snails were offered food) on juvenile growth and survival at different temperatures. Offspring produced in the laboratory by wild specimens of M. cornuarietis, from Puerto Rico, were used to test the effects of three types of food (lettuce, alginate with fish food, alginate with snail mix) fed at three frequencies (given ad libitum on 4/4, 2/4, or 1/4 d) on juvenile survival and growth. The 4-d feeding regimens were repeated four times, giving a total of 16 d for the experiments. The experiments were conducted at two temperatures (22° and 25°C) under a 12 h light:12 h dark photoperiod. Juvenile growth rates increased with increasing feeding frequency for all food types. The most rapid growth rates occurred in the high-frequency lettuce treatments and the slowest growth rates in the low-frequency lettuce and alginate with snail mix treatments. Juvenile snails grew faster at 25° than at 22°C, and mortality was about twice as high at the lower temperature. Growth rates were used to provide a rough estimate of time to maturity, which was determined to take about twice as long at 22° than at 25°C. The results showed that lettuce is the best food if supplied in abundance, but effects on growth are very dependent on feeding frequency and temperature. We conclude that 25°C is a more appropriate temperature for maintaining populations than 22°C, that lettuce provides a suitable food source, and that food should be supplied continuously for husbandry and toxicity testing of populations of M. cornuarietis