Obesity in adults: an emerging problem in urban areas of Ho Chi Minh City, Vietnam

OBJECTIVE: To assess the prevalence of overweight, obesity and underweight among Vietnamese adults living in urban areas of Ho Chi Minh City (HCMC), Vietnam. DESIGN: This cross-sectional survey was conducted in the local health stations of 30 randomly selected wards, which represent all 13 urban districts of HCMC, over a period of 2 months from March to April 2004. SUBJECTS: A total of 1488 participants aged 20-60 years completed the interview, physical examination and venous blood collection. MEASUREMENTS: Anthropometric measurements of body weight, height, waist and hip circumference were taken to construct indicators of adiposity including body mass index (BMI), waist circumference, and waist-to-height and waist-to-hip ratios. Both systolic and diastolic blood pressure and biochemical indicators of cardiovascular disease and type II diabetes risk (lipid profile and fasting blood glucose) were also measured. RESULTS: The age and sex standardized prevalence of overweight and obesity using Asian specific BMI cutoffs of 23.0 and 27.5 kg/m2 was 26.2 and 6.4%, respectively. The prevalence of overweight and obesity was slightly higher in females (33.6%) than males (31.6%), and progressively increased with age. The age and sex-standardized prevalence of underweight (BMI <18.5 kg/m2) among Vietnamese adults living in HCMC was 20.4%. The prevalence was slightly higher in males (22.0%) than in females (18.9%), and there was a much higher prevalence in all underweight categories in younger women than in men but this was reversed for older men. CONCLUSION: The adult population in HCMC Vietnam is in an early 'nutrition transition' with approximately equal prevalence of low and high BMI. The prevalence of overweight and obesity of Vietnamese urban adults was lower than that reported for other east and southeast Asian countries.

Variation at the DRD4 locus is associated with wariness and local site selection in urban black swans

 BACKGROUND: Interactions between wildlife and humans are increasing. Urban animals are often less wary of humans than their non-urban counterparts, which could be explained by habituation, adaptation or local site selection. Under local site selection, individuals that are less tolerant of humans are less likely to settle in urban areas. However, there is little evidence for such temperament-based site selection, and even less is known about its underlying genetic basis. We tested whether site selection in urban and non-urban habitats by black swans (Cygnus atratus) was associated with polymorphisms in two genes linked to fear in animals, the dopamine receptor D4 (DRD4) and serotonin transporter (SERT) genes.

RESULTS: Wariness in swans was highly repeatable between disturbance events (repeatability&thinsp;=&thinsp;0.61) and non-urban swans initiated escape from humans earlier than urban swans. We found no inter-individual variation in the SERT gene, but identified five DRD4 genotypes and an association between DRD4 genotype and wariness. Individuals possessing the most common DRD4 genotype were less wary than individuals possessing rarer genotypes. As predicted by the local site selection hypothesis, genotypes associated with wary behaviour were over three times more frequent at the non-urban site. This resulted in moderate population differentiation at DRD4 (FST&thinsp;=&thinsp;0.080), despite the sites being separated by only 30 km, a short distance for this highly-mobile species. Low population differentiation at neutrally-selected microsatellite loci and the likely occasional migration of swans between the populations reduces the likelihood of local site adaptations.

CONCLUSION: Our results suggest that wariness in swans is partly genetically-determined and that wary swans settle in less-disturbed areas. More generally, our findings suggest that site-specific management strategies may be necessary that consider the temperament of local animals.

Improving Indigenous Access to Early Childhood Services in Urban and Regional Areas

The literature on how to improve Indigenous access to early childhood services consists mainly of program descriptions and documented practice experience, with a limited number of formal program evaluations. Accessible early childhood services fulfil four overlapping dimensions. They are physically accessible; economically accessible (affordable); appropriate (comprehensive and non-discriminatory); and acceptable (respect and acknowledge culture).The literature suggests that there are five types of barriers to accessible early childhood services: individual; program; provider; social and neighbourhood; and cultural.It is not sufficient to just improve access—engagement strategies are also necessary to get families involved in the services that may benefit them.

Keeping it clean : bird bath hygiene in urban and rural areas

In a dry continent like Australia where the provision of water in bird baths is a common and popular practice, very little is known about it. We describe the use of different types of bird baths and how these were maintained by residents (n&thinsp;=&thinsp;1,728 respondents). The most commonly monitored bird baths were pedestal/elevated baths (>80%). Participants refilled bird baths more frequently in summer compared with winter (water changed once a day: winter respondents, 37.5%; summer respondents, 53.8%). Bird baths were also cleaned regularly (‘Yes I do’: 26.4%; winter respondents, 23.1%; summer respondents; ‘I do but not every time’, 55.6% winter respondents, 58.6% summer respondents). Overall our study indicates good hygiene practices for the maintenance of bird baths, which may help prevent the spread of avian diseases; and that residents are providing water seemingly based on the perceived need for water by birds.

Biotic effects of climate change in urban environments: The case of the grey-headed flying-fox (Pteropus poliocephalus) in Melbourne, Australia

Urban climates are known to differ from those of the surrounding rural areas, as human activities in cities lead to changes in temperature, humidity and wind regimes. These changes can in turn affect the geographic distribution of species, the behaviour of animals and the phenology of plants. The grey-headed flying-fox (Pteropus poliocephalus) is a large, nomadic bat from eastern Australia that roosts in large colonies known as camps. Historically a warm temperate to tropical species, P. poliocephalus recently established a year-round camp in the Royal Botanic Gardens Melbourne. Using a bioclimatic analysis, we demonstrated that on the basis of long-term data, Melbourne does not fall within the climatic range of other P. poliocephalus camp sites in Australia. Melbourne is drier than other summer camps, and cooler and drier than other winter camps. The city also receives less radiation, in winter and annually, than the other summer and winter camps of P. poliocephalus. However, we found that temperatures in central Melbourne have been increasing since the 1950s, leading to warmer conditions and a reduction in the number of frosts. In addition, artificial watering of parks and gardens in the city may contribute the equivalent of 590 mm (95% CI: 450–720 mm) of extra rainfall per year. It appears that human activities have increased temperatures and effective precipitation in central Melbourne, creating a more suitable climate for camps of the grey-headed flying-fox. As demonstrated by this example, anthropogenic climate change is likely to complicate further the task of conserving biological diversity in urban environments.

Introduced birds in urban remnant vegetation : does remnant size really matter?

Introduced birds are a pervasive and dominant element of urban ecosystems. We examined the richness and relative abundance of introduced bird species in small (1–5 ha) medium (6–15 ha) and large (>15 ha) remnants of native vegetation within an urban matrix. Transects were surveyed during breeding and non-breeding seasons. There was a significant relationship between introduced species richness and remnant size with larger remnants supporting more introduced species. There was no significant difference in relative abundance of introduced species in remnants of different sizes. Introduced species, as a proportion of the relative abundance of the total avifauna (native and introduced species), did not vary significantly between remnants of differing sizes. There were significant differences in the composition of introduced bird species between the different remnant sizes, with large remnants supporting significantly different assemblages than medium and small remnants. Other variables also have substantial effects on the abundance of introduced bird species. The lack of significant differences in abundance between remnant sizes suggests they were all equally susceptible to invasion. No patches in the urban matrix are likely to be unaffected by introduced species. The effective long-term control of introduced bird species is difficult and resources may be better spent managing habitat in a way which renders it less suitable for introduced species (e.g. reducing areas of disturbed ground and weed dominated areas).

Family average income and diagnosed Type 2 diabetes in urban and rural residents in regional mainland China.

Aims: To explore the relationship between family average income (FAI; an index of socio-economic status) and Type 2 diabetes in a region of mainland China. Methods: Population-based cross-sectional study, conducted between October 2000 and March 2001 in administrative villages (n = 45) randomly selected from three urban districts and two rural counties of NanJing municipality, mainland China, with a regional population of 5.6 million. Participants were all local residents aged ≥ 35 years old (n = 29 340); 67.7% from urban areas, 32.3% from rural areas, 49.8% male and 50.2% female. Results: The response rate of eligible participants was 90.1%. The overall prevalence of self-reported Type 2 diabetes was 1.9%. After adjustment for possible confounding variables (age, gender, area of residence, body mass index, educational level, smoking status, occupational and leisure-time physical activity), participants in the higher and middle FAI categories were more than twice as likely to have Type 2 diabetes as those in the lower FAI category. Conclusions: The prevalence of Type 2 diabetes is positively related to socio-economic status (indexed by FAI) in Chinese at the population level. After controlling for potential confounding factors, people in higher socio-economic status groups are more likely to have Type 2 diabetes. These associations are consistent with other effects of epidemiological transition and identify a need for preventive initiatives.

Landscape influences on avian density in urban remnant vegetation

The management of urban environments is an increasingly important issue on an international scale as humans emigrate from rural areas to cities. Designing cities that can sustain mass human expansion while maintaining biodiversity is becoming an increasingly complex challenge for land managers. This is largely due to the lack of knowledge on how urbanization impacts upon biodiversity. Our previous research has highlighted the importance of urban remnant vegetation for avian diversity, but also suggested that landscape scale influences may have considerable impacts on the ability for a remnant to sustain species. We have since conducted a study examining avian diversity in 38 urban remnants ranging in size from 5ha to 107ha. These sites vary in relation to the quality of vegetation in the patch and their level of isolation from other remnant patches. This talk discusses the relative influences of remnant patch size, vegetation quality and isolation on avian diversity in urban remnant vegetation. We discuss how the findings of this research could be applied to managing avian diversity in the urban landscape.

Activity preferences and participation of school-age children living in urban and rural environments

It is important for therapists to be knowledgeable about the impact of the environment on children’s participation patterns and activity preferences. This study investigated the activity preference and participation among school-age children living in urban and rural locations. The participation patterns and preferences for activities of 58 typically developing children (32 males and 26 females; response rate of 38.7%) aged 8–12 years were assessed across both urban (n = 24) and rural (n = 34) regions of southwest Victoria, Australia. The participation patterns and preferences for activities were assessed using the Children’s Assessment of Participation and Enjoyment and Preferences for Activities of Children (CAPE/PAC).An independent samples t-test was used to determinewhether significant differences existed for theCAPE/PACscores for urban and rurally based children as well as boys and girls. Significant differences were found between the scores of children living in urban and rural areas on the following subscales: CAPE Diversity, CAPE Intensity, CAPE Whom, CAPE Where, PAC Physical Preference, and PACSocial Preference.Asignificant difference for rural and urban groups was found on the following CAPE activity types:Recreation Diversity,Recreation Intensity, Social Diversity, Social Intensity, Self-Improvement Diversity, and Self-Improvement Intensity. Rurally based children were engaged in a broader range of activities and did so more frequently than urban children. Differences in gender were identified with girls preferring to participate in social and skill-based activities and being more likely to participate with friends or people outside their home. However, there were no significant differences in the participation patterns of boys and girls. Physical, social, and structural aspects of the location where a child lives impact the frequency, type of activities, and whom a child participates with most frequently in out-of-school activities. The activity participation of boys and girls in Australia has become quite similar.

Simulating urban growth in a developing nation's region using a cellular automata-based model

Urbanization is one of the most evident global changes. Research in the field of urban growth modelling has generated models that explore for drivers and components of the urban growth dynamics. Cellular automata (CA) modeling is one of the recent advances, and a number of CA-based models of urban growth have produced satisfactory simulations of spatial urban expansion over time. Most application and test of CA-based models of urban growth which provide likely and reliable simulations has been developed in urban regions of developed nations; urban regions in the United States, in particular. This is because most of the models were developed in universities and research centers of developed nations, and these regions have the required data, which is extensive. Most of the population growth in the world, however, occurs in the developing world. While some European countries show signs of stabilization of their population, in less developed countries, such as India, population still grows exponentially. And this growth is normally uncoordinated, which results in serious environmental and social problems in urban areas. Therefore, the use of existing dynamic–spatial models of urban growth in regions of developing nations could be a means to assist planners and decision makers of these regions to understand and simulate the process of urban growth and test the results of different development strategies. The pattern of growth of urban regions of developing nations, however, seems to be different of the pattern of developed countries. The former use to be more dense and centralized, normally expanding outwards from consolidated urban areas; while the second is normally more fragmented and sparse. The present paper aims to investigate to how extent existing CA-based urban growth models tested in developed nations can also be applied to a developing country urban area. The urban growth model was applied to Porto Alegre City, Brazil. An expected contiguous expansion from existing urban areas has been obtained as following the historical trends of growth of the region. Moreover, the model was sensitive and able to portray different pattern of growth in the study area by changing the value of its parameters.

Do food and physical activity environments vary between disadvantaged urban and rural areas? Findings from the READI study

Issues addressed: The presence or absence of amenities in local neighbourhood environments can either promote or restrict access to opportunities to engage in healthy and/or less healthy behaviours. Rurality is thought to constrain access to facilities and services. This study investigated whether the presence and density of environmental amenities related to physical activity and eating behaviours differs between socioeconomically disadvantaged urban and rural areas in Victoria, Australia.

Methods: We undertook cross-sectional analysis of environmental data collected in 2007-08 as part of the Resilience for Eating and Activity Despise Inequality (READI) study. These data were sourced and analysed for 40 urban and 40 rural socioeconomically disadvantaged areas. The variables examined were the presence, raw count, count/km², and count/'000 population of a range of environmental amenities (fast-food restaurants, all supermarkets (also separated by major chain and other supermarkets), greengrocers, playgrounds, gyms/leisure centres, public swimming pools and public open spaces).

Results: A greater proportion of urban areas had a fast-food restaurant and gym/leisure centre present while more rural areas contained a supermarket and public swimming pool. All amenities examined (with the exception of swimming pools) were more numerous per km² in urban areas, however rural areas had a greater number of all supermarkets, other supermarkets, playgrounds, swimming pools and public open area per '000 population.

Conclusion: Although opportunities to engage in healthy eating and physical activity exist in many rural areas, a lower density per km² suggests a greater travel distance may be required to reach these.

Gender wage discrimination in rural and urban labour markets of Bangladesh

Female wages in Bangladesh are significantly lower than male wages. This paper quantifies the extent to which discrimination can explain this gender wage gap across the rural and urban labour markets of Bangladesh, using unit record data from the 1999–2000 Labour Force Survey. The gender wage differential is decomposed into a component that can be explained by differences in productive characteristics and a component not explained by observable productive differences, which is attributed to discrimination. An attempt is also made to improve on the standard methodology by implementing a wage-gap decomposition method that accounts for selectivity bias, on top of the usual “explained” and “unexplained” components. Analytical results from this paper show that gender wage differentials are considerably larger in urban areas than in rural areas and a significant portion of this wage differential can be attributed to discrimination against women. The results also show that selectivity bias is an important component of total discrimination.

Zonal banning and public order in urban Australia

In recent years, Australian governments of various ideological persuasions at local, state and territory and federal levels have introduced a range of zonal governing techniques to manage the flow of people in urban spaces. Zonal governance involves the identification and formal declaration of a specific urban geographic region to enable police and security personnel to deploy special powers and allied forms of surveillance technologies as a supplement to their conventional public order maintenance functions.

Despite the impetus towards open flows or movement within sovereign territories or larger territorial groupings, such as the European Union, considerable governmental effort has been directed towards the use of new forms of criminal law to re-territorialize urban space through new administrative, property law and regulatory measures. These low-level spatial demarcations introduce various supplementary police powers and discretionary procedures that enhance surveillance within a declared area to increase the level of contemporary urban security. Of particular concern is the legal right to ban or exclude “undesirable” individuals and groups from entering or using certain designated urban zones, to prevent antisocial or violent behavior usually associated with alcohol consumption.

To date, most discussion of the impact of banning and related surveillance measures focuses on illegal migration through ports of entry into sovereign nations and the commensurate burdens this creates for both citizens and non-citizens to authenticate their movements at national geographic borders. This logic is permeating more localized forms of regulation adopted by Australian local and mid-tier state and territory governments to control the movement of people in and out of major event sites and in the urban night-time economy.

A survey of recent reforms in the state of Victoria reveals how this new logic of mass-surveillance aims to promote greater levels of urban security while reshaping the conventional order maintenance functions of both the public and private police. This chapter describes these procedures and their impact in sanctioning the efficient screening of people to promote order in specific zones within the contemporary Australian urban environment, at the expense of more progressive and inclusive crime prevention initiatives. We focus on two exemplars of the intensification of surveillance through zonal governance techniques: ‘major events’ and ‘designated alcohol zones’.

Regional versus urban differences in teenage alcohol use: Does parental disapproval account for these differences?

Objective: To investigate if parental disapproval of alcohol use accounts for differences in adolescent alcohol use across regional and urban communities. Design: Secondary data analysis of grade-level stratified data from a random sample of schools. Setting: High schools in Victoria, Australia. Participants: A random sample of 10273 adolescents from Grade 7 (mean age=12.51 years), 9 (14.46 years) and 11 (16.42 years). Main outcome measures: The key independent variables were parental disapproval of adolescent alcohol use and regionality (regional/ urban), and the dependent variable was past 30 days alcohol use. Results: After adjusting for potential confounders, adolescents in regional areas were more likely to use alcohol in the past 30 days (OR=1.83, 1.44 and 1.37 for Grades 7, 9 and 11, respectively, P<0.05), and their parents have a lower level of disapproval of their alcohol use (b=-0.12, -0.15 and -0.19 for Grades 7, 9 and 11, respectively, P<0.001). Bootstrapping analyses suggested that 8.37%, 23.30% and 39.22% of the effect of regionality on adolescent alcohol use was mediated by parental disapproval of alcohol use for Grades 7, 9 and 11 participants respectively (P<0.05). Conclusions: Adolescents in urban areas had a lower risk of alcohol use compared with their regional counterparts, and differences in parental disapproval of alcohol use contributed to this difference.

Temporal variation of faecal indicator bacteria in tropical urban storm drains

Human faecal contamination poses a widespread hazard for human health. In urban areas, sewer leakage may be an important cause of faecal pollution to surface water. Faecal indicator bacteria (FIB) are the most widely used indicators to monitor surface water quality. However, assessing whether a water body is meeting water quality criteria is made difficult by the high variability of FIB concentrations over time. In this study, the variation of FIB concentration in surface water from tropical urban catchments is investigated. Eleven urban sub-catchments were sampled hourly over 24-hr and samples analysed for FIB. It was found that FIB show a diurnal pattern that is characterised by daytime FIB concentrations that are significantly higher than nighttime FIB concentrations. This observed diurnal variation of FIB closely follows that of sewer flows and contrasts with observations in rural streams where FIB concentrations are known to be low in the daytime and high during the night. Field tracer tests provide qualitative evidence of sewage exfiltration and transport to drains via preferential flow paths. The diurnal FIB variation and field tracer tests indicate the likelihood of surface water contamination due to leaking sewers. The results further suggest that contamination of surface-water drains is likely a widespread problem in tropical urban areas due to extensive drainage networks and the persistence of FIB under tropical conditions. Because of FIB variation over time, the time at which samples are collected is important in being able to capture the daily maximum and minimum FIB concentrations. The Kruskal-Wallis test shows that hourly sampling from 04:00 to 07:00 and from 12:00 to 15:00 results in significantly different FIB concentration (minimum and maximum, respectively). Furthermore, the Wilcoxon-Mann-Whitney test shows that sampling at 12:00 and 14:00 results in significantly higher FIB concentrations, while sampling at 05:00 and 04:00 or 05:00 and 06:00 results in significantly lower FIB concentrations, than sampling at other hours of the day.