Histone H2B.8 compacts flowering plant sperm through chromatin phase separation.

Sperm chromatin is typically transformed by protamines into a compact and transcriptionally inactive state1,2. Sperm cells of flowering plants lack protamines, yet they have small, transcriptionally active nuclei with chromatin condensed through an unknown mechanism3,4. Here we show that a histone variant, H2B.8, mediates sperm chromatin and nuclear condensation in Arabidopsis thaliana. Loss of H2B.8 causes enlarged sperm nuclei with dispersed chromatin, whereas ectopic expression in somatic cells produces smaller nuclei with aggregated chromatin. This result demonstrates that H2B.8 is sufficient for chromatin condensation. H2B.8 aggregates transcriptionally inactive AT-rich chromatin into phase-separated condensates, which facilitates nuclear compaction without reducing transcription. Reciprocal crosses show that mutation of h2b.8 reduces male transmission, which suggests that H2B.8-mediated sperm compaction is important for fertility. Altogether, our results reveal a new mechanism of nuclear compaction through global aggregation of unexpressed chromatin. We propose that H2B.8 is an evolutionary innovation of flowering plants that achieves nuclear condensation compatible with active transcription.

Linker histone H1 drives heterochromatin condensation via phase separation in Arabidopsis.

In the eukaryotic nucleus, heterochromatin forms highly condensed, visible foci known as heterochromatin foci (HF). These HF are enriched with linker histone H1, a key player in heterochromatin condensation and silencing. However, it is unknown how H1 aggregates HF and condenses heterochromatin. In this study, we established that H1 facilitates heterochromatin condensation by enhancing inter- and intrachromosomal interactions between and within heterochromatic regions of the Arabidopsis (Arabidopsis thaliana) genome. We demonstrated that H1 drives HF formation via phase separation, which requires its C-terminal intrinsically disordered region (C-IDR). A truncated H1 lacking the C-IDR fails to form foci or recover HF in the h1 mutant background, whereas C-IDR with a short stretch of the globular domain (18 out of 71 amino acids) is sufficient to rescue both defects. In addition, C-IDR is essential for H1's roles in regulating nucleosome repeat length and DNA methylation in Arabidopsis, indicating that phase separation capability is required for chromatin functions of H1. Our data suggest that bacterial H1-like proteins, which have been shown to condense DNA, are intrinsically disordered and capable of mediating phase separation. Therefore, we propose that phase separation mediated by H1 or H1-like proteins may represent an ancient mechanism for condensing chromatin and DNA.

Beyond transcription: compelling open questions in plant RNA biology.

The study of RNAs has become one of the most influential research fields in contemporary biology and biomedicine. In the last few years, new sequencing technologies have produced an explosion of new and exciting discoveries in the field but have also given rise to many open questions. Defining these questions, together with old, long-standing gaps in our knowledge, is the spirit of this article. The breadth of topics within RNA biology research is vast, and every aspect of the biology of these molecules contains countless exciting open questions. Here, we asked 12 groups to discuss their most compelling question among some plant RNA biology topics. The following vignettes cover RNA alternative splicing; RNA dynamics; RNA translation; RNA structures; R-loops; epitranscriptomics; long non-coding RNAs; small RNA production and their functions in crops; small RNAs during gametogenesis and in cross-kingdom RNA interference; and RNA-directed DNA methylation. In each section, we will present the current state-of-the-art in plant RNA biology research before asking the questions that will surely motivate future discoveries in the field. We hope this article will spark a debate about the future perspective on RNA biology and provoke novel reflections in the reader.

Evaluating the effectiveness of implementing a more severe law on prevention of road traffic injury mortality in mainland China: an interrupted time series study based on national mortality surveillance.

BACKGROUND: In China, road traffic injury (RTI) is the seventh-leading cause of death More than 1.5 million adults in China live with permanent disabilities due to road traffic accidents. In 2011, the Chinese government implemented a more severe law that increased the penalty points and fines for persons charged with drink-driving as a criminal offence. OBJECTIVES: This study evaluated the short-term and long-term effects of the drink-driving law. It also aimed to establish whether punishments of increased severity resulted in greater reductions in RTI mortality. METHODS: RTI mortality data was obtained from the Disease Surveillance Points System. A two-level interrupted time series model was used to analyse daily and monthly road traffic mortality rates, accounting for the varying trends among counties. RESULTS: The overall RTI mortality rate showed a decreasing trend from 2007 to 2015 in mainland China, especially after 2011, and similarly decreasing trends were noted among males and females and in urban and rural areas. After the Criminal Law and Road Traffic Law amendment was implemented in 2011, charging drink-driving as a criminal offence, the immediate daily RTI mortality rate reduced by 1.57% (RR=0.9843, 95% CI: 0.9444 to 1.0259), while the slope change significantly decreased by 0.04% (RR=0.9996, 95% CI: 0.9994 to 0.9997) compared with the period before the Law was revised. Stratified analysis showed that the effect size of the law was higher for males in urban and high socioeconomic circumstances (SEC) than females in rural and low and moderate SEC. Meanwhile, the increase in penalty points for dangerous driving behaviours showed no significant effects. CONCLUSION: Evidence was found that charging criminal responsibility for drink-driving is associated with reducing RTI deaths in China.

What types of green space disrupt a lonelygenic environment? A cohort study.

INTRODUCTION: Associations between green space type and social loneliness (a scarcity of people one feels they can depend on) were investigated in city-living participants in the Sax Institute's 45 and Up Study. METHODS: Availability of green space, tree canopy and open grass were measured as a percentage of land-use within 1.6 km road-network distance buffers using high-resolution data. Multilevel logistic regressions adjusted for confounding tested associations between each green space indicator with the odds of social loneliness at baseline (prevalence) and follow-up (incidence), adjusted for demographic and socioeconomic confounders. RESULTS: The prevalence of social loneliness at baseline was 5.3% (n = 5627 /105,498). Incidence of social loneliness at follow-up was 3.4% (n = 1772/51,365). Adjusted regressions indicated reduced odds of prevalent (OR = 0.95, 95%CI = 0.92-0.98) and incident social loneliness with 10% more green space (OR = 0.92, 95%CI = 0.90- 0.96). Similar associations were found with a 10% increase in tree canopy for both prevalent (OR = 0.92, 95%CI = 0.88-0.95) and incident social loneliness (OR = 0.92, 95%CI = 0.88-0.97). Two-way interaction terms indicated effect modification by sex but not couple status. Among women, a 10% increase in total green space was associated with lower odds of prevalent (OR = 0.95, 0.91-0.95) and incident (OR = 0.89, 0.85-0.95) social loneliness. A 10% increase in tree canopy among women was associated with lower odds of prevalent (OR = 0.89, 085-0.92) and incident (OR = 0.85, 0.80-0.92) social loneliness. Meanwhile, a 10% increase in open grass among women was associated with higher odds of prevalent (OR = 1.08, 1.01-1.15) and incident (OR = 1.19, 1.03-1.35) social loneliness. Associations for men were statistically significant for a 10% increase in total green space (OR = 0.96, 0.92-0.99) and tree canopy (OR = 0.93, 0.90-0.97) for prevalent social loneliness only. CONCLUSION: Urban greening and tree canopy restoration may reduce risks of social loneliness, perhaps especially in women.

AXR1 affects DNA methylation independently of its role in regulating meiotic crossover localization.

Meiotic crossovers (COs) are important for reshuffling genetic information between homologous chromosomes and they are essential for their correct segregation. COs are unevenly distributed along chromosomes and the underlying mechanisms controlling CO localization are not well understood. We previously showed that meiotic COs are mis-localized in the absence of AXR1, an enzyme involved in the neddylation/rubylation protein modification pathway in Arabidopsis thaliana. Here, we report that in axr1-/-, male meiocytes show a strong defect in chromosome pairing whereas the formation of the telomere bouquet is not affected. COs are also redistributed towards subtelomeric chromosomal ends where they frequently form clusters, in contrast to large central regions depleted in recombination. The CO suppressed regions correlate with DNA hypermethylation of transposable elements (TEs) in the CHH context in axr1-/- meiocytes. Through examining somatic methylomes, we found axr1-/- affects DNA methylation in a plant, causing hypermethylation in all sequence contexts (CG, CHG and CHH) in TEs. Impairment of the main pathways involved in DNA methylation is epistatic over axr1-/- for DNA methylation in somatic cells but does not restore regular chromosome segregation during meiosis. Collectively, our findings reveal that the neddylation pathway not only regulates hormonal perception and CO distribution but is also, directly or indirectly, a major limiting pathway of TE DNA methylation in somatic cells.

The Arabidopsis epigenetic regulator ICU11 as an accessory protein of Polycomb Repressive Complex 2.

Molecular mechanisms enabling the switching and maintenance of epigenetic states are not fully understood. Distinct histone modifications are often associated with ON/OFF epigenetic states, but how these states are stably maintained through DNA replication, yet in certain situations switch from one to another remains unclear. Here, we address this problem through identification of Arabidopsis INCURVATA11 (ICU11) as a Polycomb Repressive Complex 2 accessory protein. ICU11 robustly immunoprecipitated in vivo with PRC2 core components and the accessory proteins, EMBRYONIC FLOWER 1 (EMF1), LIKE HETEROCHROMATIN PROTEIN1 (LHP1), and TELOMERE_REPEAT_BINDING FACTORS (TRBs). ICU11 encodes a 2-oxoglutarate-dependent dioxygenase, an activity associated with histone demethylation in other organisms, and mutant plants show defects in multiple aspects of the Arabidopsis epigenome. To investigate its primary molecular function we identified the Arabidopsis FLOWERING LOCUS C (FLC) as a direct target and found icu11 disrupted the cold-induced, Polycomb-mediated silencing underlying vernalization. icu11 prevented reduction in H3K36me3 levels normally seen during the early cold phase, supporting a role for ICU11 in H3K36me3 demethylation. This was coincident with an attenuation of H3K27me3 at the internal nucleation site in FLC, and reduction in H3K27me3 levels across the body of the gene after plants were returned to the warm. Thus, ICU11 is required for the cold-induced epigenetic switching between the mutually exclusive chromatin states at FLC, from the active H3K36me3 state to the silenced H3K27me3 state. These data support the importance of physical coupling of histone modification activities to promote epigenetic switching between opposing chromatin states.

Development of a composite healthy ageing score: evidence from middle-to-older aged Australians.

We developed and validated a composite healthy ageing score (HAS) to address the absence of a definitive composite score comprising multiple health domains that measure healthy ageing in epidemiology. The HAS is developed from 13 health domains reported to influence healthy ageing. Data to measure these domains was extracted from the 45 and Up Study baseline. We applied best practices for scale validation and development. Physical functioning, cognitive function, mental health, sleep, quality of life, balance, social connections and overall health were retained. Functional capacity and resilience were uncovered as underlying latent structures. The HAS ranges from 0 to 16 with higher scores indicating a better health profile. This research contributes a comprehensive measuring tool, HAS, It enables examination and comparison of individual or collective health profiles and the investigation of the factors that influence their chances of living healthy for longer.

The proportion of the population living longer is increasing, but longevity does not necessarily imply ageing well. Advancements in medicine have made it possible for people to live longer even while managing multiple ailments. The determinants of how well one age result from a complex interaction of various factors. This paper examined thirteen factors that can influence healthy ageing to construct a healthy ageing score comprising the crucial health domains relevant to ageing well. We found that 8 of the 13 health domains, namely: physical functioning, cognitive function, balance and falls, overall health, mental health, quality of life, sleep and social connections were crucial to ageing well. Individuals were scored a 2, a 1 or 0 based on whether they met recommended levels for each domain item and aggregated as the healthy ageing score. The score ranges from 0 to 16, with higher scores indicating a healthier ageing profile.

Leafier Communities, Healthier Hearts: An Australian Cohort Study of 104,725 Adults Tracking Cardiovascular Events and Mortality Across 10 Years of Linked Health Data.

OBJECTIVE: Green space reduces cardiovascular disease (CVD) risk, but few studies examine what types of green space matter, which is an important consideration as cities densify and apartments become more common. METHOD: Participants were 86,727 in houses and 17,998 in apartments from the 45 and Up Study (Sax Institute) baseline survey with 10 years of linked hospitalisation and death data used to define: (i) all-cause; and (ii) CVD-mortality; (iii) fatal and non-fatal CVD events; and (iv) acute myocardial infarction (AMI). Associations with total green space, tree canopy cover and open grass within 1.6 km buffers were assessed using survival analysis adjusted for potential confounders. RESULTS: Mean percentage green space indicators were all higher among participants in houses than in apartments. Among residents of houses, a 10% increase in total green space was associated with reduced risk of CVD mortality (HR 0.97, 95%CI 0.95-1.00). A 10% increase in tree canopy cover was associated with reduced risks of all-cause mortality (HR 0.97, 95%CI 0.95-0.99), CVD mortality (HR 0.96, 95%CI 0.93-0.98), and fatal or non-fatal AMI (HR 0.93, 95%CI 0.89-0.96). In contrast, a 10% increase in open grass was associated with an increased risk of fatal or non-fatal AMI (HR 1.15, 95%CI 1.09-1.20) in residents of houses. Among residents of apartments, a 10% increase in total green space was associated with increased risk of all-cause mortality (HR 1.04, 95%CI 1.00-1.08) and CVD mortality (HR 1.03, 95%CI 1.00-1.08). CONCLUSIONS: Urban reforestation may be a population-level intervention to protect cardiovascular health, especially for people living in houses. The intersection of urban greening and cardiovascular health among residents of apartments warrants further investigation.

Need and Interest in Nature Prescriptions to Protect Cardiovascular and Mental Health: A Nationally-Representative Study With Insights for Future Randomised Trials.

OBJECTIVE: "Nature prescriptions" are increasingly being adopted by health sectors as an adjunct to standard care to attend to health and social needs. We investigated levels of need and interest in nature prescriptions in adults with cardiovascular diseases, psychological distress and concomitants (e.g. physical inactivity, sedentary behaviour, obesity, loneliness, burn-out). METHODS: A nationally-representative survey of 3,319 adults across all states and territories of Australia was completed in February 2021 (response 84.0%). Participants were classified across 15 target groups using validated health indicators and surveyed on (1) time and frequency of visits to green and blue spaces (nature spaces), (2) interest in a nature prescription, and (3) potential confounders (e.g. age, income). Analyses were done using weighted logistic regressions. RESULTS: The sample was 50.5% female, 52.0% were aged ≥45 years, 15.2% were living alone and 19.3% were born overseas in non-English-speaking countries. Two-thirds of the sample spent 2 hours or more a week in nature, but these levels were generally lower in target groups (e.g. 57.7% in adults with type 2 diabetes). Most participants (81.9%) were interested in a nature prescription, even among those spending fewer than 2 hours a week in nature (76.4%). For example, 2 hours a week or more in nature was lowest among sedentary adults (36.9%) yet interest in nature prescriptions in this group was still high (74.0%). Lower levels of nature contact in target groups was not explained by differences in access to or preference for local nature spaces. CONCLUSIONS: High levels of interest in nature prescriptions amid low levels of nature contact in many target health groups provides impetus for developing randomised trials of interventions that enable people to spend more time in nature. These findings can inform intervention co-design processes with a wide range of community stakeholders, end-users in target health groups, and the health professionals who support them.

Protocol for a novel sodium and blood pressure reduction intervention targeting online grocery shoppers with hypertension - the SaltSwitch Online Grocery Shopping randomized trial.

BACKGROUND: High dietary sodium intake is a leading cause of hypertension. A major source of dietary sodium is salt added to processed food products available in retail food environments. The fast-growing online grocery shopping setting provides new opportunities for salt reduction interventions that support consumers in choosing healthier options. METHODS: The SaltSwitch Online Grocery Shopping randomized controlled trial is investigating the feasibility, acceptability, and effectiveness of a novel intervention for lowering salt consumption and blood pressure amongst people with hypertension who shop for groceries online. The intervention is based on a bespoke web browser extension that interfaces with a major retailer's online store to highlight and interpret product sodium content and suggest similar but lower-sodium alternatives. The primary outcome of interest is change in mean systolic blood pressure between individuals randomized (1:1) to the intervention and control (usual online shopping) arms at 12 weeks. Secondary outcomes are diastolic blood pressure, spot urinary sodium and sodium:potassium ratio, sodium purchases, and dietary intake. Intervention implementation and lessons for future uptake will be assessed using a mixed methods process evaluation. Participants with hypertension who shop online for groceries and exhibit high sodium purchasing behavior are being recruited across Australia. A target sample size of 1,966 provides 80% power (2-sided alpha = 0.05) to detect a 2 mm Hg difference in systolic blood pressure between groups, assuming a 15 mm Hg standard deviation, after allowing for a 10% dropout rate. DISCUSSION: This trial will provide evidence on an innovative intervention to potentially reduce salt intake and blood pressure in people with hypertension. The intervention caters to individual preferences by encouraging sustainable switches to similar but lower-salt products. If effective, the intervention will be readily scalable at low cost by interfacing with existing online retail environments.

Association between built environments and weight status: evidence from longitudinal data of 9589 Australian children.

BACKGROUND: No studies appear to examine potential associations between changes in built environments across childhood and the developmental trajectories of child weight status. OBJECTIVE: Examine the developmental trajectories of child weight status with respect to changes in childhood exposure to the built environments. METHODS: This study used data of 9589 children with biennial follow-up (2004-2016), retrieved from the Longitudinal Study of Australian Children. Changes in objectively-measured child weight status (i.e., body mass index-BMI, waist circumference) were investigated in relation to changes in seven built environments (i.e., neighbourhood safety; green space quality; footpaths and street conditions; public transport; shopping facilities; basic services; and local traffic) subjectively reported by caregivers. Group-based discrete trajectory mixture models were used to classify children according to their developmental trajectories of built environments and weight status. Multilevel multinomial logistic regression was employed to examine associations between built environments and child weight status adjusted for confounding. RESULTS: Two, four, and six trajectory groups were developed for built environment variables. Three groups namely "moderate", "high", and "extreme increase" were generated for each BMI and waist circumference. Findings from multilevel analyses indicated that growing up in neighbourhoods that are considered highly safe, with better quality of green space nearby, and in areas with low local traffic over time are protective against unhealthy weight increase in childhood. Meanwhile, living with better access to shopping facilities and basic services was associated with an unhealthy increase in BMI and/or waist circumference. No clear associations appeared between the quality of footpath and street conditions, access to public transport, and child weight status. CONCLUSIONS: Built environments might act either as a risk or protective factor of an unhealthy increase in child weight status. Enabling health-promoting neighbourhoods (i.e., highly safe, quality green space nearby, low local traffic) is important to support a healthy weight trajectory across childhood.

Caregiver perceptions of neighbourhood green space quality, heavy traffic conditions, and asthma symptoms: Group-based trajectory modelling and multilevel longitudinal analysis of 9,589 Australian children.

BACKGROUND: This study assessed the associations between changes in exposure to green space quality, heavy traffic conditions, and asthma symptoms among children. METHODS: 10-year cohort data of 9589 children, retrieved from the Longitudinal Study of Australian Children, were analysed. Caregiver-reported neighbourhood green space quality, heavy traffic conditions, and asthma symptoms were measured biennially. Group-based trajectory mixture models were used to develop trajectory groups, denoting different patterns of, or changes in, exposure to green space quality, heavy traffic conditions, and asthma symptoms across childhood. Multilevel multinomial logistic regression was used to identify factors associated with trajectory group membership and examine the confounders-adjusted associations between trajectory groups of green space quality, heavy traffic conditions, and asthma symptoms. RESULTS: Four trajectory groups for each green space quality and heavy traffic conditions, and five trajectory groups for asthma symptoms were developed. Children in less disadvantaged areas were more likely to be in trajectory groups with exposure to quality green space, but less likely to be exposed to heavy neighbourhood traffic. Living in more remote areas was associated with the decreased likelihood to be in groups with exposure to both quality green space and heavy traffic conditions over time. Accumulation of exposure to quality green space across childhood was not found to be protective against asthma symptoms. However, children whose caregiver perceptions of heavy traffic conditions trended from low to moderate levels; or were consistently in high levels across childhood had a higher likelihood to be in trajectory groups with a higher risk of asthma symptoms. CONCLUSION: Exposure to quality green space was not associated with the reduced risk of asthma symptoms. The accumulation of exposure to heavy traffic conditions increased the likelihood of asthma symptoms among children. Reducing the presence of heavy traffic in neighbourhoods might reduce the risk of childhood asthma.

Green space quality and adolescent mental health: do personality traits matter?

INTRODUCTION: Adolescents, especially females, tend to experience poorer mental health if they are higher in introversion and neuroticism. As a result, they also may have more to gain from having quality green space (e.g. parks) nearby to enable restoration, but this remains tested. METHOD: Cross-sectional data on 2946 adolescents aged 16-17y were extracted from the Longitudinal Study of Australian Children. Multilevel linear regressions assessed association between parent/caregiver green space quality perception with self-reported Strengths and Difficulties Questionnaire Total Difficulties Scores (TDS) and internalising (e.g. anxiety) and externalising (e.g. fidgetiness) subscales. Models were weighted for representativeness, accounted for spatial clustering within postcodes, and adjusted for geographic stratum and socioeconomic confounders. This was followed by adjustment for introversion and neuroticism, and then three-way interaction terms between each trait, green space quality and sex to assess for potential effect modification. RESULTS: Quality green spaces was associated with higher TDS (ß = 1.506; SE = 0.371), internalising (ß = 0.982; SE = 0.220) and externalising (ß = 0.518; SE = 0.234) scores (i.e. poorer mental health). Introversion was associated with higher TDS (ß = 1.416; SE = 0.089), higher internalising (ß = 1.233; SE = 0.050) and higher externalising scores (ß = 0.181; SE = 0.056). Similar associations were observed for neuroticism and TDS (ß = 2.283; SE = 0.084), internalising (ß = 1.627; SE = 0.046) and externalising scores (ß = 0.656; SE = 0.056). Mean levels of introversion were similar for girls and boys (1.73 vs 1.76, p = 0.6573), but mean levels of neuroticism were notably higher in girls than boys (2.42 and 1.67, p < 0.0001). Likelihood ratio tests indicated three-way interactions improved models analysing the internalising subscale outcome only. Green space quality made no difference to associations between introversion or neuroticism and internalising scores in males. Quality green space was associated with 3.2 and 2.1 reductions in mean internalising scores among females with the highest levels of introversion or neuroticism, respectively. CONCLUSIONS: Individual differences in psychological traits may predispose some adolescents, and females especially, to restoration from green space.

Weekly green space visit duration is positively associated with favorable health outcomes in people with hypertension: Evidence from Shenzhen, China.

BACKGROUND: Studies from high income 'western' countries indicate that green space visit duration is associated with better health. However, scant comparable research has been done in developing countries with rapid urbanization and on the potential health impacts of specific green infrastructure. OBJECTIVE: Associations between green space visit duration, green infrastructure and various health outcomes were assessed in hypertensive patients. METHODS: A stratified multi-stage cluster random sampling method was applied to select 1116 patients with hypertension aged 35 years or older in Shenzhen, China. Face-to-face survey, physical examination and laboratory biochemical tests were applied to obtain information. Binary logistic regressions with restricted cubic splines were used to explore the degree of linearity in associations between green space visit duration and the following health outcomes: central obesity; diabetes; blood pressure; dyslipidemia; poor physical health; poor mental health. Models were adjusted for age, sex, education, marital status, occupation, and socioeconomic status. Further analysis was made for presence of the following health promoting green infrastructure: health knowledge promotion areas; walking trails; fitness areas; group exercise venues. RESULTS: Each additional 30 min green space visitation was linearly associated with lower odds of self-reported poor mental health [OR (95%CI): 0.937 (0.891-0.985)], self-reported poor physical health [OR (95%CI): 0.918 (0.872-0.966)], and central obesity [OR (95%CI): 0.951 (0.907-0.997)]. Odds of poor mental health [OR (95%CI): 0.886 (0.788-0.997)], poor physical health [OR (95%CI): 0.882 (0.782-0.996)] and central obesity [OR (95%CI): 0.855 (0.765-0.955)] were founded to decrease with a greater number of health promoting green infrastructure. CONCLUSION: More time spent in green space and with more types of green infrastructure were favourably associated with central obesity, and physical and mental health in people with hypertension.

The nexus between urban green space, housing type, and mental health.

INTRODUCTION: Momentum for urban densification is increasing opportunities for apartment-living, but can result in reduced green space availability that negatively influences mental health. However, in contexts where apartment-living is atypical and commonly viewed as secondary to house-ownership, it may be a stressful antecedent condition (or marker of selective processes aligned with psychological distress) wherein occupants could benefit disproportionately from green space. METHOD: Data were extracted from the Sax Institute's 45 and Up Study baseline (2006-2009, n = 267,153). The focus was on subsets of 13,196 people living in apartments and 66,453 people living in households within the cities of Sydney, Newcastle and Wollongong. Multilevel models adjusted for confounders tested associations between psychological distress (Kessler 10 scale) with percentage total green space, tree canopy and open grass within 1.6 km road network buffers. RESULTS: Psychological distress was higher in occupants of apartments (11.3%) compared with houses (7.9%). More green space was associated with less psychological distress for house-dwellers (OR = 0.94, 95% CI = 0.91-0.98), but there was no association for apartment-dwellers. More tree canopy was associated with lower psychological distress for house-dwellers (OR = 0.88, 95% CI = 0.85-0.92) and apartment-dwellers (OR = 0.87, 95% CI = 0.79-0.96). Open grass was associated with more psychological distress among house-dwellers (OR = 1.06, 95% CI = 1.00-1.13) and also for apartment-dwellers (OR = 1.20, 95% CI = 1.07-1.35). CONCLUSIONS: Overall, investments in tree canopy may benefit the mental health of house and apartment residents relatively equally. Urban tree canopy in densely populated areas where apartments are common needs to be protected. Further work is needed to understand factors constraining the prevention potential of open grass, to unlock its benefits for mental health.

Is prosocial behaviour a missing link between green space quality and child health-related outcomes?

BACKGROUND: This study aimed to investigate prosocial behaviour-those behaviours that benefit others or enhance relationships with others-as a mediator of the associations between green space quality and child health-related outcomes (physical activity, mental health, and health-related quality of life (HRQOL)). METHODS: This study involved data from 4983 children with 10-year follow-up (2004-2014) retrieved from the Longitudinal Study of Australian Children. Green space quality (the exposure), prosocial behaviour (the candidate mediator), and child health-related outcomes were assessed biennially based on caregiver reports. Causal mediation analysis was used, with four mediation models developed for each outcome. RESULTS: Mediation by prosocial behaviour appeared in the late childhood mediation model with higher mediation proportions reported compared to models of earlier and middle childhood. Prosocial behaviour had moderate mediation consistency for the association between green space quality and physical activity enjoyment, but no mediation was evident for other physical activity variables. Prosocial behaviour had low mediation consistency for child mental health (internalising and externalising subscales). Similarly, low mediation consistency of prosocial behaviour was also evident for all HRQOL variables, such as physical, emotional, social, school functioning, psychosocial health, and total quality of life (QOL). CONCLUSION: Prosocial behaviour partially mediated the association between green space quality and child health-related outcomes (physical activity enjoyment, mental health, and HRQOL). Improving the quality of neighbourhood green space that supports the development of prosocial behaviour may result in better child health-related outcomes. Other physical activity variables might not specifically relate to social interactions, and therefore, no mediation by prosocial behaviour was apparent.

DNA methylation dynamics during germline development.

DNA methylation plays essential homeostatic functions in eukaryotic genomes. In animals, DNA methylation is also developmentally regulated and, in turn, regulates development. In the past two decades, huge research effort has endorsed the understanding that DNA methylation plays a similar role in plant development, especially during sexual reproduction. The power of whole-genome sequencing and cell isolation techniques, as well as bioinformatics tools, have enabled recent studies to reveal dynamic changes in DNA methylation during germline development. Furthermore, the combination of these technological advances with genetics, developmental biology and cell biology tools has revealed functional methylation reprogramming events that control gene and transposon activities in flowering plant germlines. In this review, we discuss the major advances in our knowledge of DNA methylation dynamics during male and female germline development in flowering plants.

Chromatin accessibility landscapes activated by cell-surface and intracellular immune receptors.

Activation of cell-surface and intracellular receptor-mediated immunity results in rapid transcriptional reprogramming that underpins disease resistance. However, the mechanisms by which co-activation of both immune systems lead to transcriptional changes are not clear. Here, we combine RNA-seq and ATAC-seq to define changes in gene expression and chromatin accessibility. Activation of cell-surface or intracellular receptor-mediated immunity, or both, increases chromatin accessibility at induced defence genes. Analysis of ATAC-seq and RNA-seq data combined with publicly available information on transcription factor DNA-binding motifs enabled comparison of individual gene regulatory networks activated by cell-surface or intracellular receptor-mediated immunity, or by both. These results and analyses reveal overlapping and conserved transcriptional regulatory mechanisms between the two immune systems.

Behavioural change, weight loss and risk of dementia: A longitudinal study.

Recent meta-analysis reported higher dementia risks associated with lower body mass index (BMI) and decreasing BMI. We examined to what extent these associations were attenuated by changes in behaviours and local environment. Multilevel discrete time-to-event models examined associations between baseline and change in BMI with dementia detected through prescription medications (source: Department of Human Services), hospitalisations and death certificates among 144,456 participants in the Sax Institute's 45 and Up Study. Models were adjusted for socioeconomic factors and measures of change in adherence to published guidelines for moderate to vigorous physical activity, sleep duration, alcohol, and fruit and vegetable consumption, as well as incidence of cardiometabolic diseases, and indicators of area-level disadvantage and rurality. Data was analysed in 2020. Higher dementia risks (albeit with imprecision) were found among participants who were underweight (Incidence Hazard Ratio (IHR) 1.30, 95%CI=0.86-1.86) and lower risks among those who were overweight (IHR=0.78, 95%CI=0.70-0.86) or obese (IHR=0.72, 95%CI=0.62-0.83) compared with 'normal' BMI. A ≥0.8 kg/m2 reduction in BMI associated with IHR=1.81 (95%CI=1.64-2.01) higher dementia risk relative to those with stable BMI. Higher dementia risk with decreasing BMI was fairly consistent relative to baseline BMI category. Adherence to physical activity and sleep duration guidelines were associated with reduced dementia risk, but neither these, nor adjustment for other behaviours and local factors, explained the BMI-dementia association. In conclusion, we replicated the BMI-dementia findings from a recent meta-analysis and provide further support to preventive strategies focussed on increasing physical activity and improving sleep duration. Other potential environmental risk factors outside of socioeconomic and urban/rural circumstances warrant investigation.