The great decline in adolescent risk behaviours: Unitary trend, separate trends, or cascade?

In many high-income countries, the proportion of adolescents who smoke, drink, or engage in other risk behaviours has declined markedly over the past 25 years. We illustrate this behavioural shift by collating and presenting previously published data (1990–2019) on smoking, alcohol use, cannabis use, early sexual initiation and juvenile crime in Australia, England, the Netherlands, New Zealand, and the USA, also providing European averages where comparable data are available. Then we explore empirical evidence for and against hypothesised causes of these declines. Specifically, we explore whether the declines across risk behaviours can be considered 1) a ‘unitary trend’ caused by common underlying drivers; 2) separate trends with behaviour-specific causes; or 3) the result of a ‘cascade’ effect, with declines in one risk behaviour causing declines in others. We find the unitary trend hypothesis has theoretical and empirical support, and there is international evidence that decreasing unstructured face-to-face time with friends is a common underlying driver. Additionally, evidence suggests that behaviour-specific factors have played a role in the decline of tobacco smoking (e.g. decreasing adolescent approval of smoking, increasing strength of tobacco control policies) and drinking (e.g. more restrictive parental rules and attitudes toward adolescent drinking, decreasing ease of access to alcohol). Finally, declining tobacco and alcohol use may have suppressed adolescent cannabis use (and perhaps other risk behaviours), but evidence for such a cascade is equivocal. We conclude that the causal factors behind the great decline in adolescent risk behaviours are multiple. While broad contextual changes appear to have reduced the opportunities for risk behaviours in general, behaviour-specific factors have also played an important role in smoking and drinking declines, and ‘knock-on’ effect from these behavioural domains to others are possible. Many hypothesised explanations remain to be tested empirically

Whole-genome sequencing reveals host factors underlying critical COVID-19

Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2–4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease

Photon asymmetry measurements of γ→ p→ π0p for Eγ= 320-650 MeV

High-statistics measurements of the photon asymmetry Σ for the γ→ p→ π0p reaction have been made in the center-of-mass energy range W= 1214 - 1450 MeV. The data were measured with the MAMI A2 real photon beam and Crystal Ball/TAPS detector systems in Mainz, Germany. The results significantly improve the existing world data and are shown to be in good agreement with previous measurements, and with the MAID, SAID, and Bonn-Gatchina predictions. We have also combined the photon asymmetry results with recent cross-section measurements from Mainz to calculate the profile functions, Σˇ (= σ0Σ) , and perform a moment analysis. Comparison with calculations from the Bonn-Gatchina model shows that the precision of the data is good enough to further constrain the higher partial waves, and there is an indication of interference between the very small F-waves and the N(1520) 3 / 2 - and N(1535) 1 / 2 - resonances

Whole-genome sequencing reveals host factors underlying critical COVID-19

Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2,3,4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease

Sex, drugs, smokes and booze: What's driving teen trends? Describing and explaining trends in adolescent sexual behaviour, cannabis use, smoking and alcohol use in the early 21st century

Today’s adolescents are far less likely to smoke, drink, use drugs or be sexually active than their 1990s counterparts. My doctoral project set out to describe and explain trends in adolescent risk behaviours in the early 21st century, considering not only New Zealand but also other high-income countries that have seen dramatic declines in adolescent risk behaviours over the past 15-20 years. To date, this megatrend in adolescent behaviour has not been widely recognised within public health, much less explained. My research questions were: 1. What are the key trends in adolescent sexual behaviour and substance use (tobacco, alcohol, cannabis) in New Zealand, Australia, England and USA, 1990-2017? What do the patterns suggest about the possible drivers of risk behaviour decline? 2. What does analysis of repeat cross-sectional data from New Zealand reveal about the drivers of declining risk behaviour in secondary school students in this country? 3. What are the possible explanations for the international decline in adolescent risk behaviours? How plausible are these explanations, based on existing theory and evidence and the findings of my own empirical analyses? 4. Do the observed declines represent separate trends with separate drivers; a single trend with common underlying driver(s); or knock on effects with declines in one risk behaviour leading to declines in others? Key trends I collated data from New Zealand, Australia, England and the USA on trends in smoking, drinking, cannabis use, and sexual behaviour among adolescents aged less than 16. I found strong declines in all of these behaviours over the past 15 to 20 years. However, there were no corresponding improvements in adolescent fruit and vegetable intake, physical activity, condom use or mental health. In fact, there were significant declines in many of these indicators. These trends were common to most (but not all) high income countries, and were distinct from adult trends. The patterns observed provide clues as to possible drivers. For example they suggest adolescents are not becoming healthier or more health-conscious in general. Countries with very different regulatory environments have similar trends, suggesting that public health interventions are probably not the primary driver. Similarities across countries and behaviours are suggestive of broad socio-cultural changes impacting on many behaviours simultaneously. However, other clues (e.g. a lag of several years between smoking decline and declines in alcohol indicators in many countries) point to the importance of behaviour-specific factors. Changing social context I investigated the changing social context, identifying some of the broad social changes that have influenced the experience of adolescence over the past 30 years. These include: - greater social concern about health and safety - greater awareness of the harms of substance use - more involved and protective parenting - increasing pressure on adolescents to prepare for a competitive job market - increasing exclusion of young people from public space - increasing time spent engaged in digital media use - declining exposure to pro-smoking influences. My literature review revealed that many hypotheses for declines in adolescent risk behaviours had been discussed in the literature but few had been empirically tested using rigorous methods. Drivers of risk behaviour decline in New Zealand Having identified potential contributory factors, I tested those for which repeat cross-sectional data was available in nationally representative New Zealand surveys: the annual ASH Year 10 Snapshot (2003-2015) and the Youth 2000 series (2001, 2007, 2012). Using regression analyses, I investigated the extent to which each hypothesised contributor accounted for trends in adolescent smoking, cannabis use, binge drinking and sexual activity in New Zealand secondary students aged less than 16 years. My findings provide evidence against several hypotheses. Factors that did not make a statistically significant contribution to adolescent trends in New Zealand included: - parental smoking, drinking and cannabis use in the home - sibling smoking - exposure to others’ smoking in the home - parental monitoring - family connectedness - school connectedness - time hanging out with peers - engagement in paid work. The main factors that influenced trends were i) large declines in the proportion of adolescents who thought smoking and drinking were acceptable in people their own age, and ii) impacts of risk behaviour trends on one another. Trends in adolescent smoking and binge drinking appear to be primarily driven by tobacco-specific and alcohol-specific factors respectively, in particular attitude changes. In contrast, declines in cannabis use and sexual activity were largely explained by declines in smoking and binge drinking. Common underlying drivers in home, school, and leisure contexts only made a very minor contribution in combination. However, the pattern of findings in the latter half of the study period (2007-2012) is consistent with a decline in going out at night with friends leading to fewer opportunities for all four risk behaviours. I used survival analysis to investigate whether age of initiation (i.e. the age that young people try smoking, drinking, using cannabis and having sexual intercourse for the first time) changed over the study period among secondary school students. I found that, consistent with US and Australian studies, age of initiation for all four outcomes increased between 2007 and 2012 in New Zealand. These findings indicate that increasing age of initiation (though not a causal explanation) helps to explain the observed risk behaviour trends in secondary students. Explanations for the international decline in risk behaviour While a full explanation for international risk behaviour trends remains elusive, some key drivers are beginning to emerge from the international evidence and my own findings. The empirically-established contributors identified thus far are mainly tobacco-specific and alcohol-specific factors such as parental rules and expectations, decreasing ease of access, and decreasing adolescent approval of smoking and drinking. Knock on effects from one risk behaviour to another also appear to be important, with evidence both from my own research and international studies indicating that declining smoking and drinking significantly explain declining cannabis use in this age group. A common driver underlying declines in many risk behaviours is a decline in unsupervised time and space. In particular, adolescents are going out with their friends in the evenings less frequently, thereby reducing opportunities for risk behaviours. It seems likely that broad social changes have created a milieu in which these more proximal factors have emerged. International evidence does not support the hypothesis that digital media use has displaced risk behaviour in terms of time use. However, the possibility that the digital revolution has contributed to a shift in the social meaning and function of substance use and sex (e.g. as rites of passage) cannot be excluded. Separate trends, single trend, or knock on effects? Behaviour-specific factors, common drivers, and knock on effects all appear to have played a role in the decline of adolescent risk behaviours. It is likely that broad cross-national influences (e.g. the digital revolution, labour market changes) are interacting with behaviour-specific factors (e.g. less permissive parental attitudes to youth alcohol use) and the existing culture in each country to produce the pattern of trends that has been observed. Conclusion The findings suggest that the picture is complex, with multiple drivers and bi-directional relationships operating in a dynamic system. The finding that risk behaviour trends impact strongly on one another underlines the importance of investigating more than one risk behaviour at a time, and exploring the relationships between them. My thesis highlights both the importance for public health of tackling complex questions about how and why behaviour changes at the population level, and also the limitations of our current tools for dealing with complexity. Overcoming these limitations may require new interdisciplinary collaborations, new methods, and new ways of thinking, but the rewards are potentially transformational

The activity gap in Aotearoa New Zealand: what it is, why it matters and what we can do about it.

ABSTRACTThe disparity in young people’s access to extracurricular activities, known as the activity gap, remains largely unexplored in Aotearoa New Zealand. In this qualitative study we aimed to identify barriers to accessing activities and potential solutions. We interviewed 12 key informants between December 2021 to February 2022 with experience in providing extracurricular activities or relevant academic or policy-making expertise. Participants identified many positive impacts from extracurricular participation including improved wellbeing, social connection, and skill development. All agreed there is inequitable access to extracurricular activities in Aotearoa New Zealand with children from low socioeconomic backgrounds most affected. Participants explained how poverty created interconnected financial, transportation and infrastructure barriers. Community-embedded extracurricular programmes with low or no fees were considered an effective measure for increasing access. We recommend existing and novel community-led programmes are supported to expand their services, including support for disadvantaged communities to access funding opportunities. We also recommend examples of good practice within schools are disseminated to seed ideas. Further government investment in infrastructure and policy is required to alleviate poverty and facilitate participation. We recognise ongoing awareness, advocacy, and action at both community and policy levels will be required to ultimately close the activity gap in Aotearoa New Zealand

Effect of tributyltin (TBT) in the metabolic activity of TBT-resistant and sensitive estuarine bacteria

The effect of tributyltin (TBT) on growth and metabolic activity of three estuarine bacteria with different TBT resistance profiles was investigated in an organic-rich culture medium (TSB) and in phosphate buffered saline (PBS) buffer. Exposure to TBT was assessed by determining its effect on growth (OD(600 nm) measurement), bacterial productivity (leucine incorporation), viability (CFU counts), aggregation and cell size (from Live/Dead analysis), ATP and NADH concentrations. TBT exposure resulted in decrease of bacterial density, cell size, and metabolic activity. In addition, cell aggregates were observed in the TBT-treated cultures. TBT strongly affected bacterial cell metabolism and seemed to exert an effect on its equilibrium, interfering with cell activity. Also, TBT toxicity was lower when cells were grown in TSB than in PBS, suggesting that a nutrient-rich growth medium can protect cells from TBT toxicity. This study contributes to our understanding of the TBT-resistant cell behavior reflected in its physiology and metabolic activity. This information is of utmost importance for further studies of TBT bioremediation.publishe

Priority actions for improving population youth mental health: An equity framework for Aotearoa New Zealand

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