Age-related differences in physical activity levels of young adults.

Purpose: To examine age-related differences in the physical activity behaviors of young adults.

Methods: We examined rates of participation in vigorous- and moderate-intensity leisure-time activity and walking, as well as an index of physical activity sufficient for health benefits in three Australian cross-sectional samples, for the age ranges of 18–19, 20–24, and 25–29 yr. Data were collected in 1991, 1996, and 1997/8.

Results: There was at least a 15% difference in vigorous-intensity leisure-time physical activity from the 18–19 yr to the 25–29 yr age groups, and at least a 10% difference in moderate-intensity leisure-time physical activity. For the index of sufficient activity there was a difference between 9 and 21% across age groups. Differences in rates of walking were less than 8%. For all age groups, males had higher rates of participation for vigorous and moderate-intensity activity than did females, but females had much higher rates of participation in walking than males. Age-associated differences in activity levels were more apparent for males.

Conclusions: Promoting walking and various forms of moderate-intensity physical activities to young adult males, and encouraging young adult females to adopt other forms of moderate-intensity activity to complement walking may help to ameliorate decreases in physical activity over the adult lifespan.

Existence and design of reduced-order scalar functional observers

In the existing literature, the existence conditions and design procedures for scalar functional observers are available for the cases where the observers’ order p is either p=1 or p=(v-1), where v is the observability index of the matrix pair (C,A). Therefore, if an observer with an order p=1 does not exist, the other option is to use a high-order observer with p=(v-1). This paper provides the existence conditions and a design procedure for scalar functional observers of order 0≤p≤2, and demonstrates the presented results with a numerical example. where K, M, E, H and G are constant matrices to be designed. The problem of observing a scalar functional or multi functionals (z(t)∈Rk , k>1) of the state vector has been the subject of numerous papers, and different algorithms have been proposed (see, [1]-[13] and references therein). There are also papers that deal with the order reduction of multi-dimensional functional observers [9,10,12,13]. For scalar functional observers, a well-known Luenberger’s classic result [1] provides an upper bound on the order with p=(v-1). It is interesting to note here that, except for a recent result of Darouach [12,13], little results have been reported on the order reduction for scalar functional observers.

Dietary composition of pregnant women is related to size of the baby at birth

The fetal origins theory of adult disease suggests that term infants who are small for their gestational age have an increased susceptibility to chronic disease in adulthood as a consequence of physiologic adaptations to undernutrition during fetal life. Consistent evidence for an influence of women's dietary composition during pregnancy on growth of their babies is lacking, despite robust effects in animal experiments. We undertook a prospective observational study of 557 women aged 18-41 y, living in Adelaide, South Australia. Diet was assessed in early and late pregnancy using an FFQ. In early pregnancy, medians for energy intake, the proportion of energy derived from protein and from carbohydrate were 9.0 MJ, 17 and 48%, respectively. In late pregnancy the corresponding medians were 9.2 MJ, 16 and 49%. In early pregnancy, the percentage of energy derived from protein was positively associated with birth weight (P = 0.02) and placental weight (P = 0.07), independently of energy intake and weight gain during pregnancy, and after adjustment for potential confounders, including maternal age, parity, and smoking. Effects were stronger among women (n = 429) who had reliable data, based on prespecified criteria including the plausibility of dietary data when referenced against estimated energy expenditure. In addition, for this subgroup, the percentage of energy from carbohydrate in early and late pregnancy was negatively associated with ponderal index of the baby, and a specific effect of protein from dairy sources was identified. These data support the proposition that maternal dietary composition has an effect on fetal growth. Maternal diet in Western societies may therefore be important for the long-term health of the child.

Change in the prevalence of overweight and obesity among young Australian, 1969-1997

BACKGROUND: Effective public policy requires information on the prevalence of overweight and obesity. OBJECTIVE: We determined changes in the population prevalence of overweight and obesity among young Australians (aged 7-15 y) from 1969 to 1985 to 1997. DESIGN: Data from 5 independent population surveys were analyzed: the Australian Youth Fitness Survey, 1969; the Australian Health and Fitness Survey, 1985; the South Australian Schools Fitness and Physical Activity Survey, 1997; the New South Wales Schools Fitness and Physical Activity Survey, 1997; and the Health of Young Victorians Study, 1997. Measured body mass index was used as the index of adiposity, and recently published body mass index cutoff values were used to categorize each subject as nonoverweight, overweight, obese, or either overweight or obese. RESULTS: For 1985-1997, the population prevalence of overweight increased by 60-70%, obesity increased 2-4-fold, and the combined overweight and obesity categories doubled. The findings were consistent across data sets and between the sexes. For 1969-1985, there was no change in the prevalence of overweight or obesity among girls, but among boys the prevalence of overweight increased by 35%, the prevalence of obesity trebled, and the prevalence of overweight and obesity combined increased by 60%. CONCLUSIONS: The data show that in 1985-1997, the prevalence of overweight and obesity combined doubled and that of obesity trebled among young Australians, but the increase over the previous 16 y was far smaller. These results should increase our sense of urgency in identifying and implementing effective responses to this major threat to public health.

Distribution of an alien aquatic snail in relation to flow variability, human activities and water quality

1. Disturbance and anthropogenic land use changes are usually considered to be key factors facilitating biological invasions. However, specific comparisons of invasion success between sites affected to different degrees by these factors are rare.

2. In this study we related the large-scale distribution of the invading New Zealand mud snail (Potamopyrgus antipodarum) in southern Victorian streams, Australia, to anthropogenic land use, flow variability, water quality and distance from the site to the sea along the stream channel.

3. The presence of P. antipodarum was positively related to an index of flow-driven disturbance, the coefficient of variability of mean daily flows for the year prior to the study.

4. Furthermore, we found that the invader was more likely to occur at sites with multiple land uses in the catchment, in the forms of grazing, forestry and anthropogenic developments (e.g. towns and dams), compared with sites with low-impact activities in the catchment. However, this relationship was confounded by a higher likelihood of finding this snail in lowland sites close to the sea.

5. We conclude that P. antipodarum could potentially be found worldwide at sites with similar ecological characteristics. We hypothesise that its success as an invader may be related to an ability to quickly re-colonise denuded areas and that population abundances may respond to increased food resources. Disturbances could facilitate this invader by creating spaces for colonisation (e.g. a possible consequence of floods) or changing resource levels (e.g. increased nutrient levels in streams with intense human land use in their catchments).

Objectively assessing "Walkability" of local communities: using GIS to identify the relevant environmental attributes.

Geographic Information Systems (GIS) may be used to measure objectively, those features of the built environment that may influence walking. Public health research on environmental determinants of physical activity in adults shows that different factors can influence walking for recreation, compared to walking for transport. Most studies have used perceived (self-report) rather than objective measures of potentially relevant environmental attributes. We describe how a previously-developed index of ‘walkability’ was operationalized in an Australian context, using available spatial data.               Attributes believed to be of relevance to walking for transport, that are measurable using GIS, are: Dwelling density (higher-density neighborhoods support greater retail and service variety, resulting in shorter, walkable distances between facilities; driving and parking are more difficult and time consuming). Connectivity (higher intersection densities provide people with a greater variety of potential routes, easier access to major roads where public transport is available and shorter times to get to destinations). Land use mix (the more varied the land use mix and built form, then the more conducive it is to walk to various destinations). Net retail area (there are more options for destinations where goods and services may be purchased and more local employment opportunities that can be reached by walking). The associations of these attributes with walking behaviors can be  examined separately, or in combination. Such GIS data are very helpful in fundamental studies of the environmental determinants of behavior, and also in applied policy research for cities, regions or local communities, to
address public health and environmental issues.

Maternal and neonatal influences on, and reproducibility of, neonatal aortic pulse wave velocity

Aortic pulse wave velocity (aPWV), a noninvasive measure of vascular stiffness, is an independent predictor of cardiovascular disease both before and in overt vascular disease. Its characteristics in early life and its relationship to maternal factors have hardly been studied. To test the hypothesis that infant aPWV was positively related to maternal anthropometry and blood pressure (BP) at 28 weeks gestation, after adjusting for neonatal anthropometry and BP, 148 babies born in Manchester were measured 1 to 3 days after birth. A high reproducibility of aPWV, assessed in 30 babies within 3 days of birth, was found with a mean difference between occasions of –0.04 m/s (95% CI: –0.08 to 0.16 m/s). Contrary to our hypothesis, a significant inverse relation was found between neonatal aPWV (mean: 4.6 m/s) and maternal systolic BP (mean: 108.9 mm Hg; r=–0.57; 95% CI: –0.67 to –0.45) but not maternal height nor weight. Neonatal aPWV was positively correlated with birth length, birth weight, and systolic BP. In multiple regression, neonatal aPWV remained significantly inversely associated with maternal systolic BP (adjusted ß coefficient: –0.032; 95% CI: –0.040 to –0.024; P<0.001), after adjustment for maternal age, birth weight, length, and neonatal BP (all independently and positively related to aPWV) and for gestational age, maternal weight, and height (unrelated). These results suggest that infant aPWV may be a useful index of infant vascular status, is less disturbing to measure than infant BP, and is sensitive to the gestational environment marked by maternal BP.

Personality, behavioural and affective characteristics of hazardous drinkers

The aim of this study was to investigate the influence of appetitive and aversive motivation on hazardous drinking behaviour by drawing on Reinforcement Sensitivity Theory (RST). A between-groups design examined differences between hazardous drinkers and matched controls on self-report and behavioural appetitive and aversive motivation. The relationship between motivational processes and changes in affective states following behavioural task performance was also examined. Data from 27 hazardous drinkers (M = 21.88 years, SD = 3.29) and 27 gender and age matched controls (M = 21.85 years, SD = 4.08) were utilised. The Card Arranging Reward Responsivity Objective Test (CARROT) assessed behavioural appetitive motivation and the computerised Q-TASK provided an index of behavioural aversive motivation. Self-report appetitive and aversive motivation was measured using the Sensitivity to Punishment and Reward Questionnaire (SPSRQ). Brief scales tapping state positive and negative affect were also administered. Hazardous drinkers were significantly higher than controls on self-report but not behavioural measures of appetitive motivation. Results also indicated that hazardous drinkers reported significantly higher levels of negative affect. These data suggest that hazardous drinkers are characterised by high trait appetitive motivation and state negative affect. It was suggested that RST may provide a useful framework for understanding both the appetitive and aversive motivational processes involved in drinking behaviour.

Out-of-home food outlets and area deprivation: case study in Glasgow, UK

Background
There is a popular belief that out-of-home eating outlets, which typically serve energy dense food, may be more commonly found in more deprived areas and that this may contribute to higher rates of obesity and related diseases in such areas.

Methods
We obtained a list of all 1301 out-of-home eating outlets in Glasgow, UK, in 2003 and mapped these at unit postcode level. We categorised them into quintiles of area deprivation using the 2004 Scottish Index of Multiple Deprivation and computed mean density of types of outlet (restaurants, fast food restaurants, cafes and takeaways), and all types combined, per 1000 population. We also estimated odds ratios for the presence of any outlets in small areas within the quintiles.

Results
The density of outlets, and the likelihood of having any outlets, was highest in the second most affluent quintile (Q2) and lowest in the second most deprived quintile (Q4). Mean outlets per 1,000 were 4.02 in Q2, 1.20 in Q4 and 2.03 in Q5. With Q2 as the reference, Odds Ratios for having any outlets were 0.52 (CI 0.32–0.84) in Q1, 0.50 (CI 0.31 – 0.80) in Q4 and 0.61 (CI 0.38 – 0.98) in Q5. Outlets were located in the City Centre, West End, and along arterial roads.

Conclusion
In Glasgow those living in poorer areas are not more likely to be exposed to out-of-home eating outlets in their neighbourhoods. Health improvement policies need to be based on empirical evidence about the location of fast food outlets in specific national and local contexts, rather than on popular 'factoids'.

Family average income and body mass index above the healthy weight range among urban and rural resicents in regional Mainland China

Objective: To explore the relationship between family average income (FAI; an index of socio-economic status) and body mass index (BMI; a widely used, inexpensive indicator of weight status) above the healthy weight range in a region of Mainland China. Design: Population-based cross-sectional study, conducted between October 1999 and March 2000 on a sample of regular local residents aged 35 years or older who were selected by random cluster sampling. Setting: Forty-five administrative villages selected from three urban districts and two rural counties of Nanjing municipality, Mainland China, with a regional population of 5.6 million. Subjects: In total, 29 340 subjects participated; 67.7% from urban and 32.3% from rural areas; 49.8% male and 50.2% female. The response rate among eligible participants was 90.1%. Results: The proportion of participants classified as overweight was 30.5%, while 7.8% were identified as obese. After adjusting for possible confounding variables (age, gender, area of residence, educational level, occupational and leisure-time physical activity, daily vegetable consumption and frequency of red meat intake), urban participants were more likely to be overweight or obese relative to their rural counterparts, more women than men were obese, and participants in the lowest FAI tertile were the least likely to be above the healthy weight range. Conclusions: The proportion of adults with BMI above the healthy weight range was positively related to having a higher socio-economic status (indexed by FAI) in a regional Chinese population.

Joint range of motion limitations in children and young adults with spinal muscular atrophy

Objectives
To elicit descriptive data about limited joint range of motion (ROM) in subjects with type II or III spinal muscular atrophy (SMA) and to examine the relation between the number of motions with limited range and both age and functional ability.
Design
Descriptive cross-sectional study.
Setting
Neurologic pediatric outpatient clinic at a hospital in Taiwan.
Participants
Twenty-seven subjects with SMA type II (mean age, 9.8±6.5y) and 17 with SMA type III (mean age, 12.2±8.7y).
Intervention
Measurement with transparent goniometers of joint ROM bilaterally of the shoulder, elbow, wrist, hip, knee, and ankle.
Main outcome measures
The proportion of participants with each ROM limitation compared with all participants with the same SMA type, age distribution of the participants with each ROM limitation, mean range loss of each motion limitation, and the contracture index (risk index of joint contracture).
Results
Eighty-nine percent of the participants with SMA type II experienced knee extension limitation. Approximately 50% of the participants with both types of SMA had ankle dorsiflexion limitation. The motions of knee and hip extension and ankle dorsiflexion also had a relatively high contracture index. The number of motions with limited range positively correlated (P<.001) with age and upper-extremity functional grade (the higher the functional grade, the poorer the functional ability) for SMA type II.
Conclusions
We found varying degrees of joint ROM limitation. Certain motions were noted to be high risks for the development of contractures. This risk was higher mostly in younger children.

A cross country analysis of dynamics in comparative advantage and trade patterns in textiles and clothing

This paper examines pattern of comparative advantage in textiles and clothing trade as revealed by export shares of selected developed and developing economies. The estimated revealed comparative advantage (RCA) indices provided strong evidence of comparative advantage enjoyed by the developing economies. However, a few developed high income economies have enjoyed sustainable comparative advantage, especially in textiles trade. Significant negative correlations are observed between country specific income levels and the estimated absolute and relative RCA indices. While most of the developing economies achieved significant improvement of comparative advantage over time in clothing trade, the evidence is mixed for textiles. Additional evidence from Grubel-Lloyd (G-L) index of intra industry trade (IIT) suggest that global textiles trade could be mainly explained on the basis of product differentiation and economies of scale while clothing trade is more based on comparative advantage. Results of the study also suggest that the trading nations should engage in exploitation of forms of competition such as product differentiation in textiles trade, whereas for clothing, cost minimising remains a valid strategy.

Temporal structure of diving behaviour in sympatric Antarctic and Subantarctic fur seals

Lactation is considerably briefer (4 vs. 10 mo) and daily pup energy expenditure higher in Antarctic (AFS) than in subantarctic fur seals (SFS), even in sympatric populations of both species, where their foraging locations and diets are similar. Therefore, lactational demands may be higher for AFS females. We investigated whether sympatric lactating AFS and SFS females differ in their physiological or behavioural diving capacities, and in the temporal structure of foraging behaviour. Mean dive depth and duration were greater in SFS, but dives below 140 m were performed only by AFS. An index of activity level during the bottom phase of dives, when fur seals are thought to capture prey, was higher in SFS. Despite these differences, SFS females showed a steady increase in the minimum postdive interval following dives lasting longer than 250 s, compared to the steady increase following dives lasting longer than only 150 s in AFS. These results suggest that physiological constraints on diving behaviour are stronger on AFS females, and that the behavioural aerobic dive limit is greater for SFS. Assuming that dive bouts reflect foraging in prey patches, AFS females exploited more patches per unit time, and remained in them for briefer periods of time, compared to SFS females. Dive bout structure did not differ between overnight and long foraging trips. Our data suggest that AFS females spend greater foraging effort, but may gain access to prey patches of better quality, which may help them cope with higher lactational demands.

Effect of deer velvet on sexual function in men and their partners: a double-blind, placebo-controlled study

The use of alternative medicines and herbal remedies is an increasing trend in Western societies. For years, people have taken products made of deer velvet for their alleged beneficial effects on sexual function. There has been no scientific investigation of the effects of deer velvet powder on the sexual functioning of human males. This study investigated sexual function in men during a 12-week double-blind, placebo-controlled trial of deer velvet. Thirty-two volunteer male participants, aged 45–65 years, and their partners, were randomly assigned to either the deer velvet or placebo study group. The males took capsules containing ground deer velvet or placebo everyday for 12 weeks. Two sexual function questionnaires (the International Index of Erectile Function and the Brief Index of Sexual Function for Women) used at pre- and posttreatment assessed changes in sexual functioning in males and their partners. Blood tests at baseline, and end of study, determined levels of sex-related hormones in male participants. There were no significant differences in the sexual behavior of the men taking deer velvet compared with the men taking placebo capsules. There were no significant hormone changes from baseline to the end of the study in either group of men. We conclude that in normal males there was no advantage in taking deer velvet to enhance sexual function. All alternative health products or nutritional supplements should be subjected to randomized placebo-controlled trials to determine efficacy.

Study of the dimensions that relate to the effectiveness of training systems : a systems approach

The purpose of this thesis is to explore dimensions that relate to the training systems effectiveness in a number of industry categories. The training system is taken as part of the reproducer boundary subsystem within the organisation (Miller 1978). The research has been developed on the assumption that no single criterion is appropriate as a measure of effectiveness of a training system (Campbell et al 1970). An index of criteria based on the different organisational variables that interact within an organisation is employed in the development of the study. In this research the structural variables (independent variables) including industry category, size and formalisation factors of the sample organisations will be related to the effectiveness of training systems in their organisations. This research attempts to formulate hypotheses in the field of training system research to contribute to a theory of training system impact studies. The popular areas of research in the field of training have mainly tended to focus separately on the effectiveness of training programmes, the economics of training, the social impact of training and the dynamics of training. To my knowledge there is no research work that tests the relationship between structure and the effectiveness of training systems.