A review of population-based prevalence studies of physical activity in adults in the Asia-Pacific region

Background: Physical activity (PA) surveillance is an important component of non-communicable disease risk factor monitoring, and occurs through national and international surveillance systems. This review identifies population PA estimates for adults in the Asia-Pacific region, and examines variation in trends and prevalence rates obtained using different PA measures.

Methods: Data were obtained from a MEDLINE search; World Health Organization’s Global Health Infobase; Government websites and reference lists of relevant papers. Inclusion criteria included: national studies or those reporting large scale population-level data; data published from 2000 to 2010 and trend data prior; sample sizes over n = 1000, or fewer subjects in small nations.

Results: In total, 56 population surveys from 29 Asia-Pacific countries were identified. Data on ‘sufficient physical activity’ amongst adults were available from 45 studies (80%), with estimates ranging from 7% to 93% (median 62%, inter-quartile range 40%-85%). For 14 countries, estimates of ‘sufficient activity’ were documented in multiple surveys using different methods, with the largest variation from 18% to 92% in Nepal. Median or mean METminutes/ day, reported in 20 studies, ranged from 6 to 1356. Serial trend data were available for 11 countries (22%), for periods spanning 2-10 years. Of these, five countries demonstrated increases in physical activity over time, four demonstrated decreases and three showed no changes.

Conclusions: Many countries in the Asia-Pacific region collect population-level PA data. This review highlights differences in estimates within and between countries. Some differences may be real, others due to variation in the PA questions asked and survey methods used. Use of standardized protocols and measures, and combined reporting of data are essential goals of improved international PA surveillance.

Cigarette smoking, nicotine dependence and anxiety disorders : a systematic review of population-based, epidemiological studies

Background Multiple studies have demonstrated that rates of smoking and nicotine dependence are increased in individuals with anxiety disorders. However, significant variability exists in the epidemiological literature exploring this relationship, including study design (cross-sectional versus prospective), the population assessed (random sample versus clinical population) and diagnostic instrument utilized.

Methods We undertook a systematic review of population-based observational studies that utilized recognized structured clinical diagnostic criteria (Diagnostic and Statistical Manual of Mental Disorders (DSM) or International Classification of Diseases (ICD)) for anxiety disorder diagnosis to investigate the relationship between cigarette smoking, nicotine dependence and anxiety disorders.

Results In total, 47 studies met the predefined inclusion criteria, with 12 studies providing prospective information and 5 studies providing quasiprospective information. The available evidence suggests that some baseline anxiety disorders are a risk factor for initiation of smoking and nicotine dependence, although the evidence is heterogeneous and many studies did not control for the effect of comorbid substance use disorders. The identified evidence however appeared to more consistently support cigarette smoking and nicotine dependence as being a risk factor for development of some anxiety disorders (for example, panic disorder, generalized anxiety disorder), although these findings were not replicated in all studies. A number of inconsistencies in the literature were identified.

Conclusions Although many studies have demonstrated increased rates of smoking and nicotine dependence in individuals with anxiety disorders, there is a limited and heterogeneous literature that has prospectively examined this relationship in population studies using validated diagnostic criteria. The most consistent evidence supports smoking and nicotine dependence as increasing the risk of panic disorder and generalized anxiety disorder. The literature assessing anxiety disorders increasing smoking and nicotine dependence is inconsistent. Potential issues with the current literature are discussed and directions for future research are suggested.

A population-based study of preschoolers' food neophobia and its associations with food preferences

Objective: This cross-sectional study was designed to investigate the relationships between food preferences, food neophobia, and children’s characteristics among a population-based sample of preschoolers.

Design: A parent-report questionnaire.

Setting: Child-care centers, kindergartens, playgroups, day nurseries, and swimming centers.

Subjects: 371 two- to five-year-old Australian children.

Outcome Measures: Associations between food neophobia and the food preferences and characteristics.

Analysis: Analysis of variance, analysis of covariance, Pearson product-moment correlations, and Fisher z test were used to estimate and compare the associations between these variables.

Results: Food neophobia was associated with reduced preferences for all food groups, but especially for vegetables (r = −0.60; P < .001). It was also associated with liking fewer food types (r = −0.55; P < .001), disliking more food types (r = 0.42; P < .001), the number of untried food types (r = 0.25; P < .001), a less varied range of food preferences (r = −0.59; P < .001), and less healthful food preferences overall (r = −0.55; P < .001). No significant relationships (P < .01) were observed between food neophobia and a child’s age, sex, or history of breast-feeding.

Conclusions: The study confirms and extends results obtained in experimental research and population-based intake studies of food neophobia to children’s everyday food preferences. The findings suggest that preschool children’s everyday food preferences are strongly associated with food neophobia but not with children’s age, sex, or history of breast-feeding. When aiming to influence children’s food preferences, the effects of food neophobia and strategies to reduce it should be considered.

Computational studies to understand the role of social learning in team familiarity and its effects on team performance

This paper concerns social learning modes and their effects on team performance. Social learning, such as by observing others' actions and their outcomes, allows members of a team to learn what other members know. Knowing what other members know can reduce task communication and co-ordination overhead, which helps the team to perform faster since members can devote their attention to their tasks. This paper describes agent-based simulation studies using a computational model that implements different social learning modes as parameters that can be controlled in the simulations. The results show that social learning from both direct and indirect observations positively contributes to learning about what others know, but the value of social learning is sensitive to prior familiarity such that minimum thresholds of team familiarity are needed to realise the benefits of social learning. This threshold increases with task complexity. These findings clarify the level of influence that sociality has on social learning and sets up a formal framework by which to conduct studies on how social context influences learning and group performance.

Automatic rule induction in Arabic to English machine translation framework

This chapter addresses the exploitation of a supervised machine learning technique to automatically induce Arabic-to-English transfer rules from chunks of parallel aligned linguistic resources. The induced structural transfer rules encode the linguistic translation knowledge for converting an Arabic syntactic structure into a target English syntactic structure. These rules are going to be an integral part of an Arabic-English transfer-based machine translation. Nevertheless, a novel morphological rule induction method is employed for learning Arabic morphological rules that are applied in our Arabic morphological analyzer. To demonstrate the capability of the automated rule induction technique, we conducted rule-based translation experiments that use induced rules from a relatively small data set. The translation quality of the hybrid translation experiments achieved good results in terms of WER.

Cause and effect in studies on unemployment, mental health and suicide: a meta-analytic and conceptual review

Background There are ongoing questions about whether unemployment has causal effects on suicide as this relationship may be confounded by past experiences of mental illness. The present review quantified the effects of adjustment for mental health on the relationship between unemployment and suicide. Findings were used to develop and interpret likely causal models of unemployment, mental health and suicide. Method A random-effects meta-analysis was conducted on five population-based cohort studies where temporal relationships could be clearly ascertained. Results Results of the meta-analysis showed that unemployment was associated with a significantly higher relative risk (RR) of suicide before adjustment for prior mental health [RR 1.58, 95% confidence interval (CI) 1.33–1.83]. After controlling for mental health, the RR of suicide following unemployment was reduced by approximately 37% (RR 1.15, 95% CI 1.00–1.30). Greater exposure to unemployment was associated with higher RR of suicide, and the pooled RR was higher for males than for females. Conclusions Plausible interpretations of likely pathways between unemployment and suicide are complex and difficult to validate given the poor delineation of associations over time and analytic rationale for confounder adjustment evident in the revised literature. Future research would be strengthened by explicit articulation of temporal relationships and causal assumptions. This would be complemented by longitudinal study designs suitable to assess potential confounders, mediators and effect modifiers influencing the relationship between unemployment and suicide.

A computational approach to the reconstruction of surface geometry from early temple superstructures

Recovering the control or implicit geometry underlying temple architecture requires bringing together fragments of evidence from field measurements, relating these to mathematical and geometric descriptions in canonical texts and proposing "best-fit" constructive models. While scholars in the field have traditionally used manual methods, the innovative application of niche computational techniques can help extend the study of artefact geometry. This paper demonstrates the application of a hybrid computational approach to the problem of recovering the surface geometry of early temple superstructures. The approach combines field measurements of temples, close-range architectural photogrammetry, rule-based generation and parametric modelling. The computing of surface geometry comprises a rule-based global model governing the overall form of the superstructure, several local models for individual motifs using photogrammetry and an intermediate geometry model that combines the two. To explain the technique and the different models, the paper examines an illustrative example of surface geometry reconstruction based on studies undertaken on a tenth century stone superstructure from western India. The example demonstrates that a combination of computational methods yields sophisticated models of the constructive geometry underlying temple form and that these digital artefacts can form the basis for in depth comparative analysis of temples, arising out of similar techniques, spread over geography, culture and time.

Heating effects on water repellency in Australian eucalypt forest soils and their value in estimating wildfire soil temperatures

Wildfires can induce or enhance soil water repellency under a range of vegetation communities. According to mainly USA-based laboratory studies, repellency is eliminated at a maximum soil temperature (T) of 280–400°C. Knowledge of T reached during a wildfire is important in evaluating post-fire soil physical properties, fertility and seedbed status. T is, however, notoriously difficult to ascertain retrospectively and often based on indicative observations with a large potential error. Soils under fire-prone Australian eucalypt forests tend to be water repellent when dry or moderately moist even if long unburnt. This study aims to quantify the temperature of water repellency destruction for Australian topsoil material sampled under three sites with contrasting eucalypt cover (Eucalyptus sieberi, E. ovata and E. baxteri). Soil water repellency was present prior to heating in all samples, increased during heating, but was abruptly eliminated at a specific T between 260 and 340°C. Elimination temperature varied somewhat between samples, but was found to be dependent on heating duration, with longest duration resulting in lowest elimination temperature. Results suggest that post-fire water repellency may be used as an aid in hindcasting soil temperature reached during the passage of a fire within repellency-prone environments.

Prevalence of genital human papillomavirus DNA in a sample of senior school-aged women in the Australian Capital Territory

Background: A strong association between persistent infection with oncogenic types of human papillomavirus (HPV) and cervical cancer is well established. Small numbers of international studies examining adolescent HPV infection and the risk factors associated are published, but there is currently no evidence on the prevalence and risk factors for HPV in an Australian, sexually active female adolescent population. Methods: To provide prevalence and risk factors for HPV in a female sexually active, senior high school population in the Australian Capital Territory (ACT), a convenience sample of 161, 16–19-year-old females attending a senior high school was evaluated. The sample formed part of a larger sample recruited for a study of sexually transmitted infections and blood-borne viruses in senior high school students. A clinical record was used to collect information about sexual and other risk behaviours, while self-collected vaginal swabs were tested for HPV DNA detection and genotyping using polymerase chain reaction. Results: The prevalence of HPV DNA in this sample overall was 11.2%, with multiple genotypes in 38%. No statistically significant associations were found between HPV DNA and the number of male partners, age of coitarche, time since first sexually active, condom use, smoking or alcohol intake. Conclusions: This is the first Australian study that has examined the prevalence and risk factors for genital HPV in this demographic group. The prevalence of HPV infection is slightly lower than reported in similar age groups overseas and is lower than other Australian studies in older women and those attending sexual health centres. Of HPV-positive young women, high-risk genotypes were found in over half, with more than one-third of HPV existing as multiple genotypes. Large community-based prevalence studies are needed to guide the development of recommendations for the vaccination of young women against HPV and to support other health promotion initiatives.

Foot mucus is a good source for non-destructive genetic sampling in polyplacophora

A non-destructive method for collecting samples for DNA analysis from the mucus of molluscs was successfully adapted for use with the genus Ischnochiton. DNA was extracted using a Chelex-based method and the COI subunit of the mtDNA was amplified and sequenced. Sequences from the mucus were crosschecked against sequences from the foot tissue of the same animal and were found to be identical. This method provides a non-destructive way of carrying out larger studies of the genetics of rare organisms and may be of general use for genetic-based field studies of molluscs.

Freshwater influences on hydrology and seagrass dynamics of intermittent estuaries

Over a three-year period, impacts of changed flow regimes in small western-Victorian estuaries with Mediterranean climates were investigated. Ecosystems with artificially increased and reduced freshwater inflows were compared using a whole-system, process-based approach. Studies on such systms are rare despite their vulnerability and ecological importance.

Maternal effects in the Zebra Finch : a model mother reviewed

Birds are a particularly good group with which to examine the importance of maternal effects, as parental contributions can be relatively easily quantified compared with other groups. There have undoubtedly been more studies on maternal effects in the Zebra Finch than any other single bird species. Studies of this species have examined the importance of maternal effects mediated through sex allocation, size, nutrients and hormones of of eggs, incubation behaviour and provisioning levels. A synthesis of all of this work illustrates some contrasting results (e.g. many high-profile results have failed to be replicated), some very common patterns (e.g. investment shifts through the laying sequence), and potentially interesting and complex interactions between traits (e.g. between sex of offspring and hormonal profiles of eggs). This extensive collection of work on the Zebra Finch provides useful general insight into the patterns of maternal investment in birds and the effects on offspring phenotype. However, we caution that the literature is probably littered with studies that have overemphasised the importance of some maternal effects and recent studies have highlighted analytical and logical flaws that have probably led to misplaced confidence in some of the findings reported to date. Finally, it is worth considering that the bulk of the literature is based on studies of captive domesticated birds and ecological and physiological data from individuals in the wild is currently lacking. The biological relevance of maternal effects documented in this model species is therefore unclear.

Stoichiometry of endothermy : shifting the quest from nitrogen to carbon

For many animals, notably herbivores, plants are often an inadequate food source given the low content of protein and high content of C-rich material. This conception is mainly based on studies on ectotherms. The validity of this conception for endotherms is unclear given their much higher carbon requirements for maintenance energy metabolism than ectotherms. Applying stoichiometric principles, we hypothesized that endotherms can cope with diets with much higher (metabolizable) carbon to nitrogen ratios than ectotherms. Using empirical data on birds, eutherian mammals, marsupials and reptiles, we compiled and compared measurements and allometric equations for energy metabolism as well as nitrogen requirements. Our analysis supports our hypothesis that plants, and especially their leaves, are generally sufficiently rich in nitrogen to fulfil protein demands in endotherms, at least during maintenance conditions, but less so in ectotherms. This has important implications with respect to community functioning and the evolution of endothermy.

A flexible receiver-driven cache replacement scheme for continuous media objects in best-effort networks

In this paper, we investigate the potential of caching to improve quality of reception (QoR) in the context of continuous media applications over best-effort networks. Specifically, we investigate the influence of parameters such as loss rate, jitter, delay and area in determining a proxy's cache contents. We propose the use of a flexible cost function in caching algorithms and develop a framework for benchmarking continuous media caching algorithms. The cost function incorporates parameters in which, an administrator and or a client can tune to influence a proxy's cache. Traditional caching systems typically base decisions around static schemes that do not take into account the interest of their receiver pool. Based on the flexible cost function, an improvised Greedy Dual (GD) algorithm called GD-multi has been developed for layered multiresolution multimedia streams. The effectiveness of the proposed scheme is evaluated by simulation-based performance studies. Performance of several caching schemes are evaluated and compared with those of the proposed scheme. Our empirical results indicate GD-multi performs well despite employing a generalized caching policy.

Physical activity for cancer survivors : a meta-analysis of randomised controlled trials

Objective To systematically evaluate the effects of physical activity in adult patients after completion of main treatment related to cancer. Design Meta-analysis of randomised controlled trials with data extraction and quality assessment performed independently by two researchers. Data sources Pubmed, CINAHL, and Google Scholar from the earliest possible year to September 2011. References from meta-analyses and reviews. Study selection Randomised controlled trials that assessed the effects of physical activity in adults who had completed their main cancer treatment, except hormonal treatment. Results There were 34 randomised controlled trials, of which 22 (65%) focused on patients with breast cancer, and 48 outcomes in our meta-analysis. Twenty two studies assessed aerobic exercise, and four also included resistance or strength training. The median duration of physical activity was 13 weeks (range 3-60 weeks). Most control groups were considered sedentary or were assigned no exercise. Based on studies on patients with breast cancer, physical activity was associated with improvements in insulin-like growth factor-I, bench press, leg press, fatigue, depression, and quality of life. When we combined studies on different types of cancer, we found significant improvements in body mass index (BMI), body weight, peak oxygen consumption, peak power output, distance walked in six minutes, right handgrip strength, and quality of life. Sources of study heterogeneity included age, study quality, study size, and type and duration of physical activity. Publication bias did not alter our conclusions. Conclusions Physical activity has positive effects on physiology, body composition, physical functions, psychological outcomes, and quality of life in patients after treatment for breast cancer. When patients with cancer other than breast cancer were also included, physical activity was associated with reduced BMI and body weight, increased peak oxygen consumption and peak power output, and improved quality of life.