Identifying protective and risk behavior patterns of online communication in young people.

INTRODUCTION: Research has investigated the association between time spent online and mental well-being, however the nuances between specific online behaviors and well-being have been less explored. This research examines how specific online behaviors (i.e., how young people are engaging online and with whom), are associated with one another, and how these patterns of behaviors are related to well-being. METHODS: We used the November 2020 and March 2021 Understanding Society COVID-19 Panel data. The sample consisted of 1432 adolescents aged 10-15 years, who participated in November 2020. Latent class analysis was used to explore patterns of online behaviors. We also investigated how sociodemographic characteristics differed across the classes, along with physical, social, and mental well-being as distal outcomes both cross-sectionally and longitudinally. RESULTS: We identified four classes: "Avid users," "Scholars," "Midways," and the "Passengers." The avid users had the highest frequency of posting online content regularly, likewise the scholars also posted online content regularly, however the scholars were differentiated by their higher frequency of schoolwork and news intake online. The midways had more complex activity characterized by talking to friends often and having a social media account, but posted online content less frequently. The passengers were the least active online as they posted pictures and videos less (76% said "never") and only 63% had a social media account. The avid users had the lowest well-being cross-sectionally and longitudinally, and the midways had lower social well-being and appearance dissatisfaction. CONCLUSIONS: Online behaviors such as regularly posting or talking to internet-only friends could be related to lower well-being. Policymakers should consider both improving regulations online and building an evidence base to enable caregivers from all backgrounds to support young people.

End-of-life care and advance care planning for outpatients with inoperable aortic aneurysms.

OBJECTIVE: A significant proportion of patients with abdominal and thoracic aortic aneurysms (AA) do not proceed to intervention after reaching treatment threshold diameter due to a combination of poor cardiovascular reserve, frailty, and aortic morphology. This patient cohort has a high mortality; however, until this study, there exist no studies on the end-of-life care conservatively managed patients receive. METHODS: This is a retrospective multicenter cohort study of 220 conservatively managed patients with AA referred to Leeds Vascular Institute (UK) and Maastricht University Medical Centre (the Netherlands) for intervention between 2017 and 2021. Demographic details, mortality, cause of death, advance care planning and palliative care outcomes were analysed to examine predictors of palliative care referral and efficacy of palliative care consultation. RESULTS: A total of 1506 patients with AA were seen over this time period, giving a nonintervention rate of 15%. There was a 3-year mortality rate of 55%, a median survival of 364 days, and rupture was the reported cause of death in 18% of the decedents. Median follow-up was 34 months. Only 8% of all patients and 16% of decedents received a palliative care consultation, which took place a median of 3.5 days before death. Patients >81 years of age were more likely to have advance care planning. Only 5% and 23% of conservatively managed patients had documentation of preferred place of death and care priorities respectively. Patients with a palliative care consultation were more likely to have these services in place. CONCLUSIONS: Only a small proportion of conservatively treated patients had advance care planning and this was far below international guidelines on end-of-life care for adults, which recommends it for each of these patients. Pathways and guidance should be implemented to ensure patients not offered AA intervention receive end-of-life care and advance care planning.

Trends in adolescent emotional problems in Wales between 2013 and 2019: the contribution of peer relationships.

BACKGROUND: Epidemiological evidence shows a substantial increase in adolescent emotional problems in many countries, but reasons for this increase remain poorly understood. We tested change in emotional problems in a national sample of young people in Wales in 2013, 2017 and 2019 using identical symptom screens, and examined whether trends were accounted for by changes in youth friendship quality and bullying. METHODS: The present study of 230,735 11-16-year olds draws on repeat cross-sectional data obtained on three occasions (2013, 2017 and 2019) in national school-based surveys in Wales (conducted by the School Health Research Network). Emotional problems were assessed with a brief validated symptom screen (the SCL-4). RESULTS: There was a significant increase in emotional problem scores between 2013 and 2019 (b[95% CI] = 1.573 [1.380, 1.765]). This increase was observed for all ages and was more pronounced for girls than boys (interaction b [95% CI] = 0.229 [0.004, 0.462]) and for young people from less affluent families (interaction b [95% CI] = -0.564[-0.809, -0.319]). Of the total sample, 14.2% and 5.7% reported frequent face-to-face and cyberbullying respectively. There were modest decreases in friendship quality and increases in rates of bullying between 2013 and 2019, but accounting for these changes did not attenuate estimates of the population-level increase in emotional problems. CONCLUSIONS: This study provides evidence of a substantial increase in emotional problems among young people in Wales, particularly for young people from less affluent backgrounds. Changes in bullying or friendship quality did not explain this increase.

Facial emotion recognition in adopted children.

Children adopted from public care are more likely to experience emotional and behavioural problems. We investigated two aspects of emotion recognition that may be associated with these outcomes, including discrimination accuracy of emotions and response bias, in a mixed-method, multi-informant study of 4-to-8-year old children adopted from local authority care in the UK (N = 42). We compared adopted children's emotion recognition performance to that of a comparison group of children living with their birth families, who were matched by age, sex, and teacher-rated total difficulties on the Strengths and Difficulties Questionnaire (SDQ, N = 42). We also examined relationships between adopted children's emotion recognition skills and their pre-adoptive histories of early adversity (indexed by cumulative adverse childhood experiences), their parent- and teacher-rated emotional and behavioural problems, and their parents' coded warmth during a Five Minute Speech Sample. Adopted children showed significantly worse facial emotion discrimination accuracy of sad and angry faces than non-adopted children. Adopted children's discrimination accuracy of scared and neutral faces was negatively associated with parent-reported behavioural problems, and discrimination accuracy of angry and scared faces was associated with parent- and teacher-reported emotional problems. Contrary to expectations, children who experienced more recorded pre-adoptive early adversity were more accurate in identifying negative emotions. Warm adoptive parenting was associated with fewer behavioural problems, and a lower tendency for children to incorrectly identify faces as angry. Study limitations and implications for intervention strategies to support adopted children's emotion recognition and psychological adjustment are discussed.

Adversity profiles of children receiving care and support from social services: A latent-class analysis of school-aged children in Wales.

BACKGROUND: Children receive care and support from social services due to the risk of harm or impeded development or because of disability. This study aimed to identify typologies of adversity experienced by children receiving care and support from social services and to explore how typologies differ by sociodemographic characteristics. METHODS: This is a cross-sectional study of 'Children Receiving Care and Support' (N = 12 792) during 2017/2018 in Wales, UK. We sought to (1) examine the prevalence of household adversities experienced by children in receipt of care and support from social services; (2) identify typologies of household adversities; and (3) explore how typologies of household adversities differ by family characteristics (demographics, measures of social disadvantage, perinatal and care factors). RESULTS: We found evidence for multiple risk factor constellations. The four-class solution suggested four distinct classes of adversities: child disability (50.0%), low adversities (20.3%), family poor health (6.7%) and multiple risks (23.0%). Children in the 'multiple risk' class were significantly more likely to be younger, more deprived and 'looked after' by the local authority compared with those in the 'low adversities' class. CONCLUSIONS: Given the presence of different constellations of household adversities, policies and interventions that address multiple risk factors simultaneously may be more effective and have longer-lasting benefits.

Young people's online communication and its association with mental well-being: results from the 2019 student health and well-being survey.

BACKGROUND: Online communication has become an integral aspect of daily life for young people internationally. Very little research has examined whether the association between social media use and well-being depends on who young people engage with (i.e. real, or virtual friendships). METHODS: Data were drawn from a subsample of students (N = 38,736) who took part in the School Health Research Network (SHRN) 2019 Student Health and Well-being (SHW) survey. A series of multivariable regression models were used to assess the association between who adolescents were communicating with online and well-being, controlling for confounders: passive social media use; friendship quality; and cyberbullying. We also tested whether these associations were modified based on gender. RESULTS: Students are highly engaged on social networking sites, and these sites are used to communicate with existing friendship groups and develop virtual friendships. Frequent online communication with best friends (b = .340, p < .001) and bigger friendship groups (b = .397; p < .001) was associated with higher levels of well-being. However, the frequency of online contact with virtual friends made online was negatively and significantly associated with well-being (b = -.760; p < .001), with a larger negative association for girls than boys. CONCLUSIONS: Online communication with virtual friendship networks were associated with lower mental well-being, with stronger associations for girls than boys; however, frequent online communication with 'real' friends was associated with better well-being. Our results indicate the importance of considering the nature of adolescent online communication, rather than just its quantity, in developing interventions to improve adolescent well-being.

Measurement invariance of the short Warwick-Edinburgh Mental Wellbeing Scale and latent mean differences (SWEMWBS) in young people by current care status.

PURPOSE: Studying mental wellbeing requires the use of reliable, valid, and practical assessment tools, such as the Short version of the Warwick-Edinburgh Mental Wellbeing Scale (SWEMWBS). Research on the mental wellbeing of children in care is sparse. The current study aims to: (1) examine the unidimensionality of SWEMWBS; (2) assess measurement invariance of SWEMWBS across children and young people in care compared to their peers not in care; and (3) investigate the latent factor mean differences between care status groups. METHODS: We used data from the 2017 School Health Research Network Student Health and Wellbeing (SHW) survey, completed by 103,971 students in years 7 to 11 from 193 secondary schools in Wales. The final data include a total of 2,795 participants (46% boys), which includes all children in care and a sub-sample of children not in care who completed the SWEMWBS scale fully and answered questions about their living situation. RESULTS: Confirmatory factor analysis supported the unidimensionality of SWEMWBS. The SWEMWBS is invariant across groups of young people in foster, residential and kinship care compared to children and young people not in care at configural, metric and scalar levels. Findings from latent mean comparisons showed that young people in care reported lower mental wellbeing than their peers, with those in residential care reporting the lowest scores. CONCLUSIONS: Findings suggest that SWEMWBS is a valid scale for measuring differences in mental wellbeing for young people in care similar to the population.

Mental health and life satisfaction among 10-11-year-olds in Wales, before and one year after onset of the COVID-19 pandemic.

BACKGROUND: In many countries, including in the United Kingdom (UK), COVID-19 social distancing measures placed substantial restrictions on children's lives in 2020 and 2021, including closure of schools and limitations on play. Many children faced milestones such as transition to secondary school having missed several months of face-to-face schooling in the previous academic years. METHODS: This paper examines change in mental health difficulties, life satisfaction, school connectedness, and feelings about transition to secondary school among 10-11-year-olds in Wales, UK, using data from repeat cross-sectional surveys before and after the onset of the COVID-19 pandemic. Participants were 4032 10-11-year-old schoolchildren. The first cohort completed a school-based survey in 2019 (prior to introduction of social distancing measures), and the second in 2021 (following full return to school after two rounds of school closure). RESULTS: The percentage of children reporting elevated emotional difficulties rose from 17% in 2019 to 27% in 2021 (Odds Ratio = 1.65; 95%CI = 1.23 to 2.20). There was no evidence of increased behavioural difficulties (OR = 1.04; 95%CI = 0.73 to 1.46). There was a tendency toward declines in life satisfaction in all analyses, but this intersected the null (OR = 0.86; 95%CI = 0.70 to 1.07). Children reported a high degree of school connectedness before and after the pandemic, with no evidence of change in ratings of teacher relationships, pupil relationships or pupil involvement in school life. There was no evidence of impacts of the pandemic on children's feelings about the transition to secondary school, with feelings becoming more positive as transition neared. Most findings were robust to a range of sensitivity analyses. CONCLUSIONS: Supporting children's emotional recovery from the COVID-19 pandemic is a public health priority requiring urgent and effective action at multiple levels of society. Maintaining connectedness to school through the pandemic may have played a role in preventing a steeper increase in child mental health difficulties.

Adverse childhood experiences and child mental health: an electronic birth cohort study.

BACKGROUND: Adverse childhood experiences (ACEs) are negatively associated with a range of child health outcomes. In this study, we explored associations between five individual ACEs and child mental health diagnoses or symptoms. ACEs included living with someone who had an alcohol-related problem, common mental health disorder or serious mental illness, or experienced victimisation or death of a household member. METHODS: We analysed data from a population-level electronic cohort of children in Wales, UK, (N = 191,035) between the years of 1998 and 2012. We used Cox regression with discrete time-varying exposure variables to model time to child mental health diagnosis during the first 15 years of life. Child mental health diagnoses include five categories: (i) externalising symptoms (anti-social behaviour), (ii) internalising symptoms (stress, anxiety, depression), (iii) developmental delay (e.g. learning disability), (iv) other (e.g. eating disorder, personality disorders), and (v) any mental health diagnosis, which was created by combining externalising symptoms, internalising symptoms and other. Our analyses were adjusted for social deprivation and perinatal risk factors. RESULTS: There were strong univariable associations between the five individual ACEs, sociodemographic and perinatal factors (e.g. gestational weight at birth) and an increased risk of child mental health diagnoses. After adjusting for sociodemographic and perinatal aspects, there was a remaining conditional increased risk of any child mental health diagnosis, associated with victimisation (conditional hazard ratio (cHR) 1.90, CI 95% 1.34-2.69), and living with an adult with a common mental health diagnosis (cHR 1.63, CI 95% 1.52-1.75). Coefficients of product terms between ACEs and deprivation were not statistically significant. CONCLUSION: The increased risk of child mental health diagnosis associated with victimisation, or exposure to common mental health diagnoses, and alcohol problems in the household supports the need for policy measures and intervention strategies for children and their families.

Charting the trajectories of adopted children's emotional and behavioral problems: The impact of early adversity and postadoptive parental warmth.

Children who are adopted from care are more likely to experience enduring emotional and behavioral problems across development; however, adoptees' trajectories of mental health problems and factors that impact their trajectories are poorly understood. Therefore, we used multilevel growth analyses to chart adoptees' internalizing and externalizing problems across childhood, and examined the associations between preadoptive risk and postadoptive protective factors on their trajectories. This was investigated in a prospective longitudinal study of case file records (N = 374) and questionnaire-based follow-ups (N = 96) at approximately 5, 21, and 36 months postadoptive placement. Preadoptive adversity (indexed by age at placement, days in care, and number of adverse childhood experiences) was associated with higher internalizing and externalizing scores; the decrease in internalizing scores over childhood was accelerated for those exposed to lower levels of preadoptive risk. Warm adoptive parenting was associated with a marked reduction in children's internalizing and externalizing problems over time. Although potentially limited by shared methods variance and lack of variability in parental warmth scores, these findings demonstrate the deleterious impact of preadoptive risk and the positive role of exceptionally warm adoptive parenting on children's trajectories of mental health problems and have relevance for prevention and intervention strategies.

Early adversity predicts adoptees' enduring emotional and behavioral problems in childhood.

Children adopted from the public care system are likely to experience a cluster of inter-related risk factors that may place them on a trajectory of mental health problems that persist across the life course. However, the specific effects of putative risk factors on children's mental health post-placement are not well understood. We conducted a prospective, longitudinal study of children placed for adoption between 2014 and 2015 (N = 96). Adoptive parents completed questionnaires at approximately 5, 21, 36, and 48 months post-placement. We used time series analysis to examine the impact of pre-adoptive risk factors [adverse childhood experiences [ACEs], number of moves, days with birth parents and in care] on children's internalizing and externalizing problems, and prosocial behavior over 4 years post-placement. Adoptees' internalizing and externalizing problems remained consistently high over the 4-year study period, but more ACEs predicted increases in internalizing and externalizing problems. Contrary to expectations, more pre-placement moves and time in care predicted fewer problems over time, but exploratory analyses of interactive effects revealed this was only the case in rare circumstances. We identify pre- and post-removal factors that may incur benefits or have a deleterious impact on adoptees' outcomes in post-adoptive family life. Our findings provide knowledge for front-line professionals in the support of adoptive families and underscore the vital need for effective early intervention.

Prevalence of gambling behaviours and their associations with socioemotional harm among 11-16 year olds in Wales: findings from the School Health Research Network survey.

BACKGROUND: Gambling opportunities are increasingly available and acceptable to many adolescents. Adolescent problem gambling has been associated with poor outcomes, such as lower reported physical and mental health. While much research has focussed on 'problem' gambling, analysing the distribution and determinants of experimentation with gambling is important in order to understand its normalization and population level consequences. This study describes the distribution of inequalities and socioemotional harms associated with adolescent gambling. METHODS: Data were drawn from a subsample of students (N = 37 363) who completed gambling questions as part of the 2017 School Health Research Network Student Health and Wellbeing Survey, representing 193 secondary schools in Wales. Using imputations, we estimated a series of single-predictor and multi-predictor regressions for count of gambling behaviours, any gambling in the past 12 months and socioemotional harms of gambling. RESULTS: Approximately two-fifths (41.0%) of respondents reported gambling in the past 12 months, of whom 16.2% reported feeling bad as a result of their own gambling. We found significant sex differences in gambling, with boys gambling more frequently than girls. Adolescents from more affluent families reported a higher count of gambling behaviours and socioemotional harms, although paradoxically, increasing affluence was also associated with lower prevalence of gambling in the last year. Non-White British ethnicities and students who felt less connected to school were more likely to engage in gambling and experience socioemotional harms. CONCLUSIONS: Our findings provide important new insights regarding risk factors in adolescence associated with gambling behaviours and socioemotional harms.

Measurement invariance properties and external construct validity of the short Warwick-Edinburgh mental wellbeing scale in a large national sample of secondary school students in Wales.

PURPOSE: The study of mental wellbeing requires reliable, valid, and practical measurement tools. One of the most widely used measures of mental wellbeing is the Warwick-Edinburgh Mental Wellbeing Scale (WEMWBS). Our aim was to examine the psychometric properties of SWEMWBS (a brief seven-item version) in a 'real-world' population sample of young people. METHODS: We used data from the 2017 School Health Research Network Student Health and Wellbeing Survey, completed by 103,971 students in years 7 to 11 from 193 secondary schools in Wales. We first estimated polychoric correlation matrices for the whole sample and by school year, and undertook a principal components analysis to check for configural invariance. Subsequently, we used a multiple-groups structural equation model with successively greater constraints to test measurement invariance. To examine external construct validity, we calculated correlations between the SWEMWBS score and four covariates: life satisfaction, somatisation, school pressure and bullying victimisation. RESULTS: Parallel analysis suggested that extraction of one factor was appropriate both overall and in each year group. Inspection of standardised loadings suggested that four items had progressively stronger correlations with the factor as students are older, but change in fit indices between models suggested that loadings and thresholds, but not residual variances, were invariant by age group. SWEMWBS scores were moderately correlated with measures of life satisfaction and somatisation, and weakly to moderately correlated with school pressure and bullying victimisation. CONCLUSIONS: This study adds to the growing evidence that SWEMWBS is appropriate for measuring mental wellbeing in young people and suggests that SWEMWBS is appropriate for tracking the development of wellbeing across adolescence.

Paramedic Assessment of Older Adults After Falls, Including Community Care Referral Pathway: Cluster Randomized Trial.

STUDY OBJECTIVE: We aim to determine clinical and cost-effectiveness of a paramedic protocol for the care of older people who fall. METHODS: We undertook a cluster randomized trial in 3 UK ambulance services between March 2011 and June 2012. We included patients aged 65 years or older after an emergency call for a fall, attended by paramedics based at trial stations. Intervention paramedics could refer the patient to a community-based falls service instead of transporting the patient to the emergency department. Control paramedics provided care as usual. The primary outcome was subsequent emergency contacts or death. RESULTS: One hundred five paramedics based at 14 intervention stations attended 3,073 eligible patients; 110 paramedics based at 11 control stations attended 2,841 eligible patients. We analyzed primary outcomes for 2,391 intervention and 2,264 control patients. One third of patients made further emergency contacts or died within 1 month, and two thirds within 6 months, with no difference between groups. Subsequent 999 call rates within 6 months were lower in the intervention arm (0.0125 versus 0.0172; adjusted difference -0.0045; 95% confidence interval -0.0073 to -0.0017). Intervention paramedics referred 8% of patients (204/2,420) to falls services and left fewer patients at the scene without any ongoing care. Intervention patients reported higher satisfaction with interpersonal aspects of care. There were no other differences between groups. Mean intervention cost was $23 per patient, with no difference in overall resource use between groups at 1 or 6 months. CONCLUSION: A clinical protocol for paramedics reduced emergency ambulance calls for patients attended for a fall safely and at modest cost.

Influence of the surface termination on the light emission of crystalline silicon nanoparticles.

The light emission properties of silicon crystalline nanoparticles (SiNPs) have been investigated using steady-state and time-resolved photoluminescence measurements carried out at 12 K and at room temperature. To enable a comparative study of the role of surface terminal groups on the optical properties, we investigated SiNPs-H ensembles with the same mean NP diameter but differing on the surface termination, namely organic-functionalized with 1-dodecene (SiNPs-C12) and H-terminated (SiNPs-H). We show that although the spectral dependence of the light emission is rather unaffected by surface termination, characterized by a single broad band peaking at ∼1.64 eV, both the exciton recombination lifetimes and quantum yields display a pronounced dependence on the surface termination. Exciton lifetimes and quantum yields are found to be significantly lower in SiNPs-H compared SiNPs-C12. This difference is due to distinct non-radiative recombination probabilities resulting from inter-NP exciton migration, which in SiNPs-C12 is inhibited by the energy barriers imposed by the bulky surface groups. The surface groups of organic-terminated SiPs are responsible for the inhibition of inter-NP exciton transfer, yielding a higher quantum yield compared to SiNPs-H. The surface oxidation of SiNPs-C12 leads to the appearance of a phenomenon of an exciton transference from to the Si core to oxide-related states that contribute to light emission. These excitons recombine radiatively, explaining why the emission quantum of the organic-terminated SiNPs is the same after surface oxidation of SiNPs-C12.

Phase separation and the 'coffee-ring' effect in polymer-nanocrystal mixtures.

The coupling between the 'coffee-ring' effect and liquid-liquid phase separation is examined for ternary mixtures of solvent, polymer and semiconductor nanocrystal. Specifically, we study mixtures of toluene, polystyrene (PS) and colloidal silicon nanocrystals (SiNCs) using real-space imaging and spectroscopic techniques to resolve the kinetic morphology of the drying front for varied molecular weight of the PS. Our results demonstrate that the size of the polymer has a significant impact on both phase-separation and drying, and we relate these observations to simulations, measured and predicted binodal curves, and the observed shape of the flow field at the contact line. The results inform a deposition process that reduces the influence of drying instabilities for low-molecular-weight polymers while paving the way for more detailed and generic computational descriptions of drying instabilities in complex fluids.

New models of emergency prehospital care that avoid unnecessary conveyance to emergency department: translation of research evidence into practice?

BACKGROUND: Achieving knowledge translation in healthcare is growing in importance but methods to capture impact of research are not well developed. We present an attempt to capture impact of a programme of research in prehospital emergency care, aiming to inform the development of EMS models of care that avoid, when appropriate, conveyance of patients to hospital for immediate care. METHODS: We describe the programme and its dissemination, present examples of its influence on policy and practice, internationally, and analyse routine UK statistics to determine whether conveyance practice has changed. RESULTS: The programme comprises eight research studies, to a value of > £4 m. Findings have been disseminated through 18 published papers, cited 274 times in academic journals. We describe examples of how evidence has been put into practice, including new models of care in Canada and Australia. Routine statistics in England show that, alongside rising demand, conveyance rates have fallen from 90% to 58% over a 12-year period, 2,721 million fewer journeys, with publication of key studies 2003-2008. COMMENT: We have set out the rationale, key features, and impact on practice of a programme of publicly funded research. We describe evidence of knowledge translation, whilst recognising limitations in methods for capturing impact.

An all-gas-phase approach for the fabrication of silicon nanocrystal light-emitting devices.

We present an all-gas-phase approach for the fabrication of nanocrystal-based light-emitting devices. In a single reactor, silicon nanocrystals are synthesized, surface-functionalized, and deposited onto substrates precoated with a transparent electrode. Devices are completed by evaporation of a top metal electrode. The devices exhibit electroluminescence centered at a wavelength of λ = 836 nm with a peak external quantum efficiency exceeding 0.02%. This all-gas-phase approach permits controlled deposition of dense, functional nanocrystal films suitable for application in electronic devices.

Cross-cohort change in parent-reported emotional problem trajectories across childhood and adolescence in the UK.

BACKGROUND: Over the past three decades, the prevalence of adolescent emotional problems (ie, anxiety and depression) has risen. Although the onset and developmental course of emotional symptoms shows high variability, no study has directly tested secular differences across development. Our aim was to investigate whether and how developmental trajectories of emotional problems have changed across generations. METHODS: We used data from two UK prospective cohorts assessed 10 years apart: the Avon Longitudinal Study of Parents and Children (ALSPAC) including individuals born in 1991-92, and the Millennium Cohort Study (MCS) with individuals born in 2000-02. Our outcome was emotional problems, assessed using the parent-rated emotional subscale of the Strengths and Difficulties Questionnaire (SDQ-E) at approximate ages 4, 7, 8, 10, 11, 13, and 17 years in ALSPAC and ages 3, 5, 7, 11, 14, and 17 years in MCS. Participants were included if the SDQ-E was completed at least once in childhood and at least once in adolescence. Trajectories were generated using multilevel growth curve models using the repeated assessments of the SDQ-E in children aged 3-17 years. FINDINGS: Data were available for 19 418 participants (7012 from ALSPAC and 12 406 from the MCS), of whom 9678 (49·8%) were female and 9740 (50·2%) were male, and 17 572 (90·5%) had White mothers. Individuals born between 2000 and 2002 had higher emotional problem scores from around 9 years (intercept statistic ß 1·75, 95% CI 1·71-1·79) than did individuals born in 1991-92 (1·55, 1·51-1·59). The later cohort had an earlier onset of problems than the earlier cohort, and sustained higher average trajectories from around 11 years, with female adolescents showing the steepest trajectories of emotional problems. Differences between cohorts peaked overall at age 14 years. INTERPRETATION: Our comparison of two cohorts of young people provides evidence that compared with a cohort assessed 10 years prior, emotional problems emerge earlier in development in the more recent cohort, and these are especially pronounced for females during mid-adolescence. Such findings have implications for public health planning and service provision. FUNDING: Wolfson Centre for Young People's Mental Health, Wolfson Foundation.

High-efficiency silicon nanocrystal light-emitting devices.

We demonstrate highly efficient electroluminescence from silicon nanocrystals (SiNCs). In an optimized nanocrystal-organic light-emitting device, peak external quantum efficiencies of up to 8.6% can be realized with emission originating solely from the SiNCs. The high efficiencies reported here demonstrate for the first time that with an appropriate choice of device architecture it is possible to achieve highly efficient electroluminescence from nanocrystals of an indirect band gap semiconductor.