Effects of the Environment on Physical Activity in New Zealand Children

Childhood obesity rates have risen steadily in recent decades along with increased urbanisation that has changed where children can play and roam freely, potentially reducing their daily energy expenditure. The relationship between aspects of the built environment and children's physical activity has therefore been identified as a public-health issue. This thesis represents a review, two studies that examined built-environment effects on children's activity, one play intervention study and two studies that investigated issues with accelerometer measurement of physical activity. Chapter two addresses the need for a quantitative review of the effects of objectively measured built-environment factors on children's objectively measured physical activity. The review included studies that used geographical information systems (GIS) or street audits to quantify the built environment with physical activity quantified by accelerometers, pedometers or global positioning systems. A key insight was that danger from vehicle traffic appears to underlie the association between physical activity and some measures of the built environment. There was inadequate research on effects of neighbourhood walkability and on the confounding effects of weather, compliance and the intensity threshold for moderate-vigorous activity. In Study 1, habitual physical activity of 227 children living in 48 residential neighbourhoods within four cities was measured with accelerometers and related to built-environment factors defined using GIS analysis and street-audit measures. Disparate built-environment effects on children’s physical activity were rationalised by classifying neighbourhoods as either safe for children’s walking or play or those where traffic danger constrained activity, which suggests that unsafe neighbourhoods need redesigning. In Study 2 the same data were analysed with a particular focus on children’s daily pattern of accelerometer steps at light and moderate-vigorous intensities. It was revealed that reductions in moderate-vigorous activity were associated with poor weather, darkness and non-school days. These reductions might be offset by interventions that encourage children to self-select outdoor or indoor activities at step cadences of ~80 per minute. Modifying the built environment is a long-term health strategy towards developing child-walkable neighbourhoods where children can roam and play independently to increase their daily physical activity. A short-to-medium term intervention plan was implemented in Study 3, a crossover design for promoting children’s increased physical activity through self-determined play during a supervised play period before school (08:00-09:00) with free access to play equipment. There were no clear changes in total activity, but during the play intervention there were trivial-small reductions in girls’ body-mass index (BMI) while boys’ BMI remained constant when normally BMI would be expected to increase. Reasons for excluding data from analysis in the intervention study were investigated in Study 4 and it was found that non-compliance and discomfort with wearing accelerometers along with monitor failure excluded half of the children from providing activity data for analyses. In the final study, the effect of accelerometer-count thresholds on the amount of activity classified as moderate-vigorous intensity was investigated and thresholds from published articles are recommended rather than manufacturer thresholds. In conclusion, future studies should investigate the effects of neighbourhoods designed to increase safety to encourage children’s habitual activity. Measurement of physical activity should be undertaken by continuously wearing accelerometers (and global positioning system watches) and analysed using published count thresholds

Addressing Inequity to Achieve the Maternal and Child Health Millennium Development Goals: Looking Beyond Averages.

Inequity in access to and use of child and maternal health interventions is impeding progress towards the maternal and child health Millennium Development Goals. This study explores the potential health gains and equity impact if a set of priority interventions for mothers and under fives were scaled up to reach national universal coverage targets for MDGs in Tanzania. We used the Lives Saved Tool (LiST) to estimate potential reductions in maternal and child mortality and the number of lives saved across wealth quintiles and between rural and urban settings. High impact maternal and child health interventions were modelled for a five-year scale up, by linking intervention coverage, effectiveness and cause of mortality using data from Tanzania. Concentration curves were drawn and the concentration index estimated to measure the equity impact of the scale up. In the poorest population quintiles in Tanzania, the lives of more than twice as many mothers and under-fives were likely to be saved, compared to the richest quintile. Scaling up coverage to equal levels across quintiles would reduce inequality in maternal and child mortality from a pro rich concentration index of -0.11 (maternal) and -0.12 (children) to a more equitable concentration index of -0,03 and -0.03 respectively. In rural areas, there would likely be an eight times greater reduction in maternal deaths than in urban areas and a five times greater reduction in child deaths than in urban areas. Scaling up priority maternal and child health interventions to equal levels would potentially save far more lives in the poorest populations, and would accelerate equitable progress towards maternal and child health MDGs

Digital multiplex ligation assay for highly multiplexed screening of beta-lactamase-encoding genes in bacterial isolates

Increasing incidence of antibiotic resistance in clinical and environmental settings calls for increased scalability in their surveillance. Current screening technologies are limited by the number of samples and genes that can easily be screened. We demonstrate here digital multiplex ligation assay (dMLA) as a low-cost targeted genomic detection workflow capable of highly-parallel screening of bacterial isolates for multiple target gene regions simultaneously. Here, dMLA is used for simultaneous detection of 1187 beta-lactamase-encoding genes, including extended spectrum beta-lactamase (ESBL) genes, in 74 bacterial isolates. We demonstrate dMLA as a light-weight and cost-efficient workflow which provides a highly scalable tool for antimicrobial resistance surveillance and is also adaptable to genetic screening applications beyond antibiotic resistance.Tamminen et al. develop a digital multiplex ligation assay (dMLA) that enables the detection of bacterial isolates using probe hybridization and ligation-based assays with next-generation sequencing. Their method can be applied in high-throughput and affordable screening for antibiotic resistance

Automated Analysis of Cryptococcal Macrophage Parasitism Using GFP-Tagged Cryptococci

The human fungal pathogens Cryptococcus neoformans and C. gattii cause life-threatening infections of the central nervous system. One of the major characteristics of cryptococcal disease is the ability of the pathogen to parasitise upon phagocytic immune effector cells, a phenomenon that correlates strongly with virulence in rodent models of infection. Despite the importance of phagocyte/Cryptococcus interactions to disease progression, current methods for assaying virulence in the acrophage system are both time consuming and low throughput. Here, we introduce the first stable and fully characterised GFP–expressing derivatives of two widely used cryptococcal strains: C. neoformans serotype A type strain H99 and C. gattii serotype B type strain R265. Both strains show unaltered responses to environmental and host stress conditions and no deficiency in virulence in the macrophage model system. In addition, we report the development of a method to effectively and rapidly investigate macrophage parasitism by flow cytometry, a technique that preserves the accuracy of current approaches but offers a four-fold improvement in speed

The Australasian Resuscitation In Sepsis Evaluation: FLUid or vasopressors In Emergency Department Sepsis, a multicentre observational study (ARISE FLUIDS observational study): Rationale, methods and analysis plan

There is uncertainty about the optimal i.v. fluid volume and timing of vasopressor commencement in the resuscitation of patients with sepsis and hypotension. We aim to study current resuscitation practices in EDs in Australia and New Zealand (the Australasian Resuscitation In Sepsis Evaluation: FLUid or vasopressors In Emergency Department Sepsis [ARISE FLUIDS] observational study).ARISE FLUIDS is a prospective, multicentre observational study in 71 hospitals in Australia and New Zealand. It will include adult patients presenting to the ED during a 30 day period with suspected sepsis and hypotension (systolic blood pressur

Hearing Ability with Age in Northern European Women: A New Web-Based Approach to Genetic Studies

Age-related hearing impairment (ARHI) affects 25–40% of individuals over the age of 65. Despite the high prevalence of this complex trait, ARHI is still poorly understood. We hypothesized that variance in hearing ability with age is largely determined by genetic factors. We collected audiologic data on females of Northern European ancestry and compared different audiogram representations. A web-based speech-to-noise ratio (SNR) hearing test was compared with pure-tone thresholds to see if we could determine accurately hearing ability on people at home and the genetic contribution to each trait compared. Volunteers were recruited from the TwinsUK cohort. Hearing ability was determined using pure-tone audiometry and a web-based hearing test. Different audiogram presentations were compared for age-correlation and reflection of audiogram shape. Using structural equation modelling based on the classical twin model the heritability of ARHI, as measured by the different phenotypes, was estimated and shared variance between the web-based SNR test and pure-tone audiometry determined using bivariate modelling. Pure-tone audiometric data was collected on 1033 older females (age: 41–86). 1970 volunteers (males and females, age: 18–85) participated in the SNR. In the comparison between different ARHI phenotypes the difference between the first two principle components (PC1–PC2) best represented ARHI. The SNR test showed a sensitivity and specificity of 89% and 80%, respectively, in comparison with pure-tone audiogram data. Univariate heritability estimates ranged from 0.70 (95% CI: 0.63–0.76) for (PC1–PC2) to 0.56 (95% CI: 0.48–0.63) for PC2. The genetic correlation of PC1–PC2 and SNR was −0.67 showing that the 2 traits share variances attributed to additive genetic factors. Hearing ability showed considerable heritability in our sample. We have shown that the SNR test provides a useful surrogate marker of hearing. This will enable a much larger sample to be collected at a fraction of the cost, facilitating future genetic association studies

Disparities and risks of sexually transmissible infections among men who have sex with men in China: a meta-analysis and data synthesis.

BACKGROUND: Sexually transmitted infections (STIs), including Hepatitis B and C virus, are emerging public health risks in China, especially among men who have sex with men (MSM). This study aims to assess the magnitude and risks of STIs among Chinese MSM. METHODS: Chinese and English peer-reviewed articles were searched in five electronic databases from January 2000 to February 2013. Pooled prevalence estimates for each STI infection were calculated using meta-analysis. Infection risks of STIs in MSM, HIV-positive MSM and male sex workers (MSW) were obtained. This review followed the PRISMA guidelines and was registered in PROSPERO. RESULTS: Eighty-eight articles (11 in English and 77 in Chinese) investigating 35,203 MSM in 28 provinces were included in this review. The prevalence levels of STIs among MSM were 6.3% (95% CI: 3.5-11.0%) for chlamydia, 1.5% (0.7-2.9%) for genital wart, 1.9% (1.3-2.7%) for gonorrhoea, 8.9% (7.8-10.2%) for hepatitis B (HBV), 1.2% (1.0-1.6%) for hepatitis C (HCV), 66.3% (57.4-74.1%) for human papillomavirus (HPV), 10.6% (6.2-17.6%) for herpes simplex virus (HSV-2) and 4.3% (3.2-5.8%) for Ureaplasma urealyticum. HIV-positive MSM have consistently higher odds of all these infections than the broader MSM population. As a subgroup of MSM, MSW were 2.5 (1.4-4.7), 5.7 (2.7-12.3), and 2.2 (1.4-3.7) times more likely to be infected with chlamydia, gonorrhoea and HCV than the broader MSM population, respectively. CONCLUSION: Prevalence levels of STIs among MSW were significantly higher than the broader MSM population. Co-infection of HIV and STIs were prevalent among Chinese MSM. Integration of HIV and STIs healthcare and surveillance systems is essential in providing effective HIV/STIs preventive measures and treatments. TRIAL REGISTRATION: PROSPERO NO: CRD42013003721