Stability of two-dimensional Roesser systems with time-varying delays via novel 2D finitesum inequalities

This study considers the problem of stability analysis of discrete-time two-dimensional (2D) Roesser systems with interval time-varying delays. New 2D finite-sum inequalities, which provide a tighter lower bound than the existing ones based on 2D Jensen-type inequalities, are first developed. Based on an improved Lyapunov-Krasovskii functional, the newly derived inequalities are then utilised to establish delay-range-dependent linear matrix inequality-based stability conditions for a class of discrete time-delay 2D systems. The effectiveness of the obtained results is demonstrated by numerical examples.

An explicit criterion for finite-time stability of linear nonautonomous systems with delays

In this paper, the problem of finite-time stability of linear nonautonomous systems with time-varying delays is considered. Using a novel approach based on some techniques developed for linear positive systems, we derive new explicit conditions in terms of matrix inequalities ensuring that the state trajectories of the system do not exceed a certain threshold over a pre-specified finite time interval. These conditions are shown to be relaxed for the Lyapunov asymptotic stability. A numerical example is given to illustrate the effectiveness of the obtained result.

Socio-economic inequalities in women`s fruit and vegetable intakes: a multilevel study of individual, social and environmental mediators

Objective: This study employed a multilevel design to test the contribution of individual, social and environmental factors to mediating socio-economic status (SES) inequalities in fruit and vegetable consumption among women. Design: A cross-sectional survey was linked with objective environmental data. Setting: A community sample involving 45 neighbourhoods. Subjects: In total, 1347 women from 45 neighbourhoods provided survey data on their SES (highest education level), nutrition knowledge, health considerations related to food purchasing, and social support for healthy eating. These data were linked with objective environmental data on the density of supermarkets and fruit and vegetable outlets in local neighbourhoods. Results: Multilevel modelling showed that individual and social factors partly mediated, but did not completely explain, SES variations in fruit and vegetable consumption. Store density did not mediate the relationship of SES with fruit or vegetable consumption. Conclusions: Nutrition promotion interventions should focus on enhancing nutrition knowledge and health considerations underlying food purchasing in order to promote healthy eating, particularly among those who are socio-economically disadvantaged. Further investigation is required to identify additional potential mediators of SES–diet relationships, particularly at the environmental level.

Low birth weight in South Asian babies in Britain: time to reduce the inequalities

Babies born in Britain to women of South Asian ethnic origin are lighter on average than the offspring of women of European origin. The causes have been incompletely elucidated but nutritional factors, low socioeconomic status and maternal pre-pregnancy weight have been implicated. This health inequality has received little policy prioritization in Britain. As further research clarifies reasons for this differential, appropriately targeted preventive strategies need to be implemented.

Personal, social and environmental determinants of educational inequalities in walking: a multilevel study

Objective: To investigate the contribution of personal, social and environmental factors to mediating socioeconomic (educational) inequalities in women’s leisure-time walking and walking for transport.
Methods: A community sample of 1282 women provided survey data on walking for leisure and transport; educational level; enjoyment of, and self-efficacy for, walking; physical activity barriers and intentions; social support for physical activity; sporting/recreational club membership; dog ownership; and perceived environmental aesthetics and safety. These data were linked with objective environmental data on the density of public open space and walking tracks in the women’s local neighbourhood, coastal proximity and street connectivity.
Results: Multilevel modelling showed that different personal, social and environmental factors were associated with walking for leisure and walking for transport. Variables from all three domains explained (mediated) educational inequalities in leisure-time walking, including neighbourhood walking tracks; coastal proximity; friends’ social support; dog ownership; self-efficacy, enjoyment and intentions. On the other hand, few of the variables examined explained educational variations in walking for transport, exceptions being neighbourhood, coastal proximity, street connectivity and social support from family.
Conclusions: Public health initiatives aimed at promoting, and reducing educational inequalities in, leisure-time walking should incorporate a focus on environmental strategies, such as advocating for neighbourhood walking tracks, as well as personal and social factors. Further investigation is required to better understand the pathways by which education might influence walking for transport.

lCT and educational (dis) advantage: families, computers and contemporary social and educational inequalities

Because access to new technologies is unequally distributed, there has been considerable debate about the growing gap between the so-called information-rich and information-poor. Such concerns have led to high-profile information technology policy initiatives in many countries. In Australia, in an attempt to 'redress the balance between the information rich and poor' by providing 'equal access to the World Wide Web' (Virtual Communities, 2002), the Australian Council of Trade Unions, Virtual Communities (a computer/software distributor) and Primus (an Internet provider) in late 1999 formed an alliance to offer relatively inexpensive computer and Internet access to union members in order to make 'technology affordable for all Australians' (Virtual Communities, 2002). In this paper, we examine four families, one of which had long-term Information and Communication Technologies (lCT) access, and three of which took advantage of the Virtual Communities offer to get home computer and Internet access for the first time. We examine their engagement with lCT and suggest that previously disadvantaged family members are not particularly advantaged by their access to lCT.

Equity-focused health impact assessment: a tool to assist policy makers in addressing health inequalities.

In Australasia (Australia and New Zealand) the use of health impact assessment (HIA) as a tool for improved policy development is comparatively new. The public health workforce do not routinely assess the potential health and equity impacts of proposed policies or programs. The Australasian Collaboration for Health Equity Impact Assessment was funded to develop a strategic framework for equity-focused HIA (EFHIA) with the intent of strengthening the ways in which equity is addressed in each step of HIA. The collaboration developed a draft framework for EFHIA that mirrored, but modified the commonly accepted steps of HIA; tested the draft framework in six different health service delivery settings; analysed the feedback about application of the draft EFHIA framework and modified it accordingly. The strategic framework shows promise in providing a systematic process for identifying potential differential health impacts and assessing the extent to which these are avoidable and unfair. This paper presents the EFHIA framework and discusses some of the issues that arose in the case study sites undertaking equity-focused HIA.

Socio-demographic inequalities in the diets of mid-aged Australian women

Objectives: This study reports on the distributions of food and nutrient intakes by socio-demographic factors for a large population sample of mid-aged Australian women participating in the Australian Longitudinal Study on Women's Health.
Design: This cross-sectional population-based study used the Cancer Council of Victoria food frequency questionnaires to derive estimates of food and nutrient intakes.
Setting: Nationwide community-based survey.
Subjects: A total of 10561 women aged 50-55 y, at the time of the survey in 2001.
Results: Analysis showed favourable patterns of food intake, with frequent consumption of many foods that are promoted as components of a healthy diet (eg, fresh fruit, leafy green and other vegetables, bread, cereals, milk and meat). Intakes of both foods and nutrients varied significantly across socio-demographic groups, with unmarried women, and women in 'labouring' occupations (eg, cleaner, factory worker, kitchenhand) having poorer nutrient intake.
Conclusions: Although many mid-aged women in this sample had generally healthful diets, women in certain socio-demographic groups (particularly unmarried women and those in labouring occupations) had nutrient intakes of concern. As well as helping to address the dearth of current data on dietary intakes in the Australian population, the results highlight the need for continued targeted public health strategies aimed at improving diet of women from the various socio-economic backgrounds.

People, places and policies – trying to account for health inequalities in impoverished neighbourhoods

Objective : We consider associations between individual, household and area-level characteristics and self-reported health.
Method : Data is taken from baseline surveys undertaken in 13 socio-economically disadvantaged neighbourhoods in Victoria (n=3,944). The neighbourhoods are sites undergoing Neighbourhood Renewal (NR), a State government initiative redressing place-based disadvantage.
Analysis :This focused on the relationship between area and compositional factors and self-reported health. Area was coded into three categories; LGA, NR residents living in public housing (NRPU) and NR residents who lived in private housing (NRPR). Compositional factors included age, gender, marital status, identifying as a person with a disability, level of education, unemployment and receipt of pensions/benefits.
Results : There was a gradient in socio-economic disadvantage on all measures. People living in NR public housing were more disadvantaged than people living in NR private housing who, in turn, were more disadvantaged than people in the same LGA. NR public housing residents reported the worst health status and LGA residents reported the best.
Conclusions : Associations between compositional characteristics of disability, educational achievement and unemployment income and poorer self-reported health were shown. They suggested that area characteristics, with housing policies, may be contributing to differences in self-reported health at the neighbourhood level.
Implications : The clustering of socio-economic disadvantage and health outcomes requires the integration of health and social support interventions that address the circumstances of people and places.

Neighbourhood socioeconomic inequalities in food access and affordability

This study investigated whether the availability and accessibility of supermarkets and fruit and vegetable stores, and the availability, variety and price of foods within these stores, varied across areas of different levels of socioeconomic disadvantage in Melbourne, Australia. Data on food store locations, and food variety and price within stores were obtained through objective audits of 45 neighbourhoods of varying socioeconomic disadvantage. Geographical accessibility of healthy food stores was mostly better amongst those living in more advantaged neighbourhoods. Availability of healthy foods within stores only slightly favoured those in advantaged neighbourhoods. However food prices favoured those living in disadvantaged areas.