The geochemistry and petrogenesis of the lower paleozoic granitoids of North Wales

The Lower Paleozoic rocks of North Wales are penetrated by numerous bodies of dolerite and intermediate-acid material which are closely associated with pillow basalts, acid and basic tuffs and ignimbrites. Igneous activity occurred throughout the Ordovician although in Snowdonia and Lleyn it reached a climax during the Caradoc stage. The present study has considered the granitoids of Snowdonia and Lleyn which are intruded as stocks, laccoliths and high level plugs (<5 km2) into clastic and volcaniclastic sediments. A substantial body of new chemical data has been obtained for over thirty intrusions. Twenty-four major and trace elements were determined on each sample by X-ray fluorescence techniques and the rare earth abundances of forty-five selected samples were measured using a radiochemical neutron activation procedure. Three distinctly different types of granitic material are recognised and their possible evolutionary mechanisms are discussed in detail. On the basis of the geochemistries of the various sampled intrusions it is concluded that they were all ultimately derived from the mantle by partial melting. One group originated from the remobilisation of calc-alkaline plutons formed by hydrous melting of the mantle wedge above a destructive plate margin. The other two groups, it is argued, evolved from tholeiitic basaltic magma by low-pressure fractional crystallisation. The goochemical affinity between some Caradocian andesitic material from Lleyn and the tonalitic-granitic intrusions of the same area has provided good evidence against a view that the latter were emplaced late in the Caledonian cycle (Silurian-Devonian). A paleo-tectonic reconstruction of the North Wales region is presented and it is claimed that the area evolved as a volcano-tectonic rift zone, a precursor of a back-arc basin

General and specific components of depression and anxiety in an adolescent population.

BACKGROUND: Depressive and anxiety symptoms often co-occur resulting in a debate about common and distinct features of depression and anxiety. METHODS: An exploratory factor analysis (EFA) and a bifactor modelling approach were used to separate a general distress continuum from more specific sub-domains of depression and anxiety in an adolescent community sample (n = 1159, age 14). The Mood and Feelings Questionnaire and the Revised Children's Manifest Anxiety Scale were used. RESULTS: A three-factor confirmatory factor analysis is reported which identified a) mood and social-cognitive symptoms of depression, b) worrying symptoms, and c) somatic and information-processing symptoms as distinct yet closely related constructs. Subsequent bifactor modelling supported a general distress factor which accounted for the communality of the depression and anxiety items. Specific factors for hopelessness-suicidal thoughts and restlessness-fatigue indicated distinct psychopathological constructs which account for unique information over and above the general distress factor. The general distress factor and the hopelessness-suicidal factor were more severe in females but the restlessness-fatigue factor worse in males. Measurement precision of the general distress factor was higher and spanned a wider range of the population than any of the three first-order factors. CONCLUSIONS: The general distress factor provides the most reliable target for epidemiological analysis but specific factors may help to refine valid phenotype dimensions for aetiological research and assist in prognostic modelling of future psychiatric episodes.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

Reduction in adolescent depression after contact with mental health services: a longitudinal cohort study in the UK

Background: Evidence regarding the association between service contact and subsequent mental health in adolescents is scarce, and previous findings are mixed. We aimed to longitudinally assess the extent to which depressive symptoms in adolescents change after contact with mental health services. Methods: As part of a longitudinal cohort study, between April 28, 2005, and March 17, 2010, we recruited 1238 14-year-old adolescents and their primary caregivers from 18 secondary schools in Cambridgeshire, UK. Participants underwent follow-up assessment at months 18 and 36. Trained researchers assessed the adolescents for current mental disorder using the Schedule for Affective Disorders and Schizophrenia for School-Age Children Present and Lifetime version (K-SADS-PL). Caregivers and adolescents reported contact with mental health services in the year before baseline. Adolescents self-reported depressive symptoms (Mood and Feelings Questionnaire [MFQ]) at each timepoint. We assessed change in MFQ sum scores from baseline contact with mental health services using multilevel mixed-effects regression adjusted for sociodemographic, environmental, individual, and mental health confounders, with multiple imputation of missing data. We used propensity score weighting to balance confounders between treatment (users of mental health services) and control (non-users of mental health services) groups. We implemented an MFQ clinical cutoff following the results of receiver operating characteristic analysis. Findings: 14-year-old adolescents who had contact with mental health services in the past year had a greater decrease in depressive symptoms than those without contact (adjusted coefficient −1·68, 95% CI −3·22 to −0·14; p=0·033). By age 17 years, the odds of reporting clinical depression were higher in individuals without contact than in service users who had been similarly depressed at baseline (adjusted odds ratio 7·38, 1·73–31·50; p=0·0069). Interpretation: Our findings show that contact with mental health services at age 14 years by adolescents with a mental disorder reduced the likelihood of depression by age 17 years. This finding supports the improvement of access to adolescent mental health services.This study was funded by The Wellcome Trust (grant number 074296), and the National Institute for Health Research Collaboration for Leadership in Applied Health Research & Care for Cambridgeshire and Peterborough

Childhood adversity subtypes and depressive symptoms in early and late adolescence

depressive symptoms between 14 and 17 years of age. The cohort was classified into four empirically determined adversity subtypes for two age periods in childhood (0–5 and 6–11 years). One subtype reflects normative/optimal family environments (n ¼ 692, 69%), while the other three subtypes reflect differential suboptimal family environments (aberrant parenting: n ¼ 71, 7%; discordant: n ¼ 185, 18%; and hazardous: n ¼ 57, 6%). Parent-rated child temperament at 14 years and adolescent self-reported recent negative life events in early and late adolescence were included in models implementing path analysis. There were gender-differentiated associations between childhood adversity subtypes and adolescent depressive symptoms. The discordant and hazardous subtypes were associated with elevated depressive symptoms in both genders but the aberrant parenting subtype only so in girls. Across adolescence the associations between early childhood adversity and depressive symptoms diminished for boys but remained for girls. Emotional temperament was also associated with depressive symptoms in both genders, while proximal negative life events related to depressive symptoms in girls only. There may be neurodevelopmental factors that emerge in adolescence that reduce depressogenic symptoms in boys but increase such formation in girls.This is the final published version. It was originally published by CUP in Development and Psychopathology here: http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=9308912&fileId=S0954579414000625

Sedimentological archives of coastal storms in South-West Wales, UK

High magnitude coastal storms have persistently threatened human communities and environments. In the British Isles their frequency and magnitude are predicted to increase in the future with advancing climate change. This study analyses sedimentological evidence from south-west Wales to assess the impacts of high magnitude coastal storms in vulnerable coastal saltmarshes in the Three Rivers Estuarine Complex, Carmarthen Bay. Storm surge saltmarsh deposits were identified following geochemical and particle size analyses and dated using radionuclides ¹³⁷Cs and ²¹⁰Pb. The sedimentological evidence is compared with regional tidal gauge and meteorological records to assess variability in storm recording and corroborate the storms which produced the sedimentological deposits. Three episodes of high magnitude saltmarsh storm surge deposition are identified in 1954, 1977 and 1981. Evidence of storm erosion or alternative forms of storm deposition were not present. The sedimentological evidence highlights the comparative rarity of major depositional events in the saltmarshes between 1929 and 2019. The recorded depositional events combined with organic accretion have contributed to maintaining saltmarsh elevation relative to sea level. There remains uncertainty surrounding the storm impacts on the saltmarshes of the Three Rivers Estuarine Complex. When the future 21st century threats of increasing regional atmospheric storminess and sea level rise are considered along with predictions of saltmarsh degradation, this study suggests further research is required to explore the sedimentological storm impacts. This could contribute to sustaining the vulnerable coastal saltmarsh environments and the important ecosystem services they provide

Childhood adversity subtypes and depressive symptoms in early and late adolescence.

This is the final version of the article. It first appeared from Cambridge University Press via http://dx.doi.org/10.1017/S0954579414000625Within a longitudinal study of 1,005 adolescents, we investigated how exposure to childhood psychosocial adversities was associated with the emergence of depressive symptoms between 14 and 17 years of age. The cohort was classified into four empirically determined adversity subtypes for two age periods in childhood (0-5 and 6-11 years). One subtype reflects normative/optimal family environments (n = 692, 69%), while the other three subtypes reflect differential suboptimal family environments (aberrant parenting: n = 71, 7%; discordant: n = 185, 18%; and hazardous: n = 57, 6%). Parent-rated child temperament at 14 years and adolescent self-reported recent negative life events in early and late adolescence were included in models implementing path analysis. There were gender-differentiated associations between childhood adversity subtypes and adolescent depressive symptoms. The discordant and hazardous subtypes were associated with elevated depressive symptoms in both genders but the aberrant parenting subtype only so in girls. Across adolescence the associations between early childhood adversity and depressive symptoms diminished for boys but remained for girls. Emotional temperament was also associated with depressive symptoms in both genders, while proximal negative life events related to depressive symptoms in girls only. There may be neurodevelopmental factors that emerge in adolescence that reduce depressogenic symptoms in boys but increase such formation in girls.This work was supported by a Wellcome Trust programme grant (Grant 74296) for the ROOTS data collection, and the NIHR Collaboration for Leadership in Applied Health Research and Care (CLAHRC; Grant RNAG/186) for Cambridgeshire and Peterborough for data analysis and manuscript preparation. The second author's (T.C.) contribution was partially supported by a Department of Health Career Scientist Award (Public Mental Health). We thank Matthew Owens, Rosie Abbott, Paul Wilkinson, and Jenny Gibson for informative discussions and suggestions throughout manuscript preparation

Outcomes of conduct problems in adolescence: 40 year follow-up of national cohort

Objective To describe long term outcomes associated with externalising behaviour in adolescence, defined in this study as conduct problems reported by a teacher, in a population based sample

Profiles of family-focused adverse experiences through childhood and early adolescence: the ROOTS project a community investigation of adolescent mental health.

BACKGROUND: Adverse family experiences in early life are associated with subsequent psychopathology. This study adds to the growing body of work exploring the nature and associations between adverse experiences over the childhood years. METHODS: Primary carers of 1143 randomly recruited 14-year olds in Cambridgeshire and Suffolk, UK were interviewed using the Cambridge Early Experiences Interview (CAMEEI) to assess family-focused adversities. Adversities were recorded retrospectively in three time periods (early and later childhood and early adolescence). Latent Class Analysis (LCA) grouped individuals into adversity classes for each time period and longitudinally. Adolescents were interviewed to generate lifetime DSM-IV diagnoses using the K-SADS-PL. The associations between adversity class and diagnoses were explored. RESULTS: LCA generated a 4-class model for each time period and longitudinally. In early childhood 69% were allocated to a low adversity class; a moderate adversity class (19%) showed elevated rates of family loss, mild or moderate family discord, financial difficulties, maternal psychiatric illness and higher risk for paternal atypical parenting; a severe class (6%) experienced higher rates on all indicators and almost exclusively accounted for incidents of child abuse; a fourth class, characterised by atypical parenting from both parents, accounted for the remaining 7%. Class membership was fairly stable (~ 55%) over time with escape from any adversity by 14 years being uncommon. Compared to those in the low class, the odds ratio for reported psychopathology in adolescents in the severe class ranged from 8 for disruptive behaviour disorders through to 4.8 for depressions and 2.0 for anxiety disorders. Only in the low adversity class did significantly more females than males report psychopathology. CONCLUSIONS: Family adversities in the early years occur as multiple rather than single experiences. Although some children escape adversity, for many this negative family environment persists over the first 15 years of life. Different profiles of family risk may be associated with specific mental disorders in young people. Sex differences in psychopathologies may be most pronounced in those exposed to low levels of family adversities.This is the published version of the article. It was published in BMC Psychiatry by BioMed Central. The online version can be found here: http://www.biomedcentral.com/1471-244X/11/109

Investigating the maximum resolution of µXRF core scanners: a 1800 year storminess reconstruction from the Outer Hebrides

Micro x-ray fluorescence (µXRF) core scanning is capable of measuring the elemental composition of lake sediment at sub-millimetre resolution, but bioturbation and physical mixing may degrade environmental signals at such fine scales. The aim of this research is to determine the maximum possible resolution at which meaningful environmental signals may be reconstructed from lake sediments using this method. Sediment from a coastal lake in the Outer Hebrides, Scotland, has been analysed using calibrated element measurements to reconstruct storminess since AD 200. We find that a Ca/K ratio in lake-core sediments reflects the presence of fine calcium carbonate shell fragments, a constituent of sand in the catchment that is washed and blown into the lake. Variations in this ratio are significantly correlated with instrumental records of precipitation and low pressures, suggesting it is a proxy for storminess. Furthermore, identification of a c. 60-year cycle supports a climatic influence on Ca/K, as this cycle is frequently identified in reconstructions of the North Atlantic Oscillation and North Atlantic sea-surface temperature. Comparison with weather records at different resolutions and spectral analysis indicate that µXRF data from Loch Hosta can be interpreted at sub-decadal resolutions (equivalent to core depth intervals of 3–5 mm in this location). Therefore, we suggest that sub-centimetre sampling using µXRF core scanning could be beneficial in producing environmental reconstructions in many lake settings where sediments are not varved