British Sample (british + sample)

Distribution by Scientific Domains

Selected Abstracts

Substance use and common child mental health problems: examining longitudinal associations in a British sample

ADDICTION, Issue 8 2010
Anna Goodman
ABSTRACT Aims To examine the longitudinal associations in both directions between mental health and substance use in adolescence. Design Three-year longitudinal cohort. Setting Britain (nationally representative sample). Participants 3607 youths aged 11,16 years at baseline. Measurements Externalizing and internalizing mental health problems were measured using brief questionnaires (parent-reported Strengths and Difficulties Questionnaire) and diagnostic interviews, including clinician-rated diagnoses of mental disorder. Substance use was measured by youth self-report, and included regular smoking, frequent alcohol consumption, regular cannabis use and ever taking other illicit drugs. Findings Externalizing (specifically behavioural) problems at baseline independently predicted all forms of substance use, with a particularly strong effect on smoking. In all cases this association showed a dose,response relationship. In contrast, although internalizing problems had a strong univariable association with smoking, this disappeared after adjusting for comorbid externalizing problems. There was little or no evidence that baseline substance use predicted mental health at follow-up. Conclusions Externalizing problems predict adolescent substance use, and adjusting for comorbid externalizing problems is vital when investigating the effects of internalizing problems. A dose,response effect of externalizing problems is seen across the full range. Programmes seeking to prevent adolescent substance use by reducing externalizing problems may therefore wish to consider population-wide interventions rather than targeting individuals only at the negative extreme. [source]

Sex determination from the occipital condyle: Discriminant function analysis in an Eighteenth and Nineteenth Century British sample

René Gapert
Abstract Fragmentary human remains compromised by different types of inhumation, or physical insults such as explosions, fires, and mutilations may frustrate the use of traditional morphognostic sex determination methods. The basicranium is protected by a large soft tissue mass comprising muscle, tendon, and ligaments. As such, the occipital region may prove useful for sex identification in cases of significantly fragmented remains. The aims of this paper are to (1) evaluate sexual dimorphism in British cranial bases by manually recorded unilateral and bilateral condylar length and width as well as intercondylar measurements and (2) develop discriminant functions for sex determination for this cranial sample. The crania selected for this study are part of the 18th,19th century documented skeletal collection of St. Bride's Church, Fleet Street, London. Adult human skulls (n = 146; ,75/,71) were measured to derive statistical functions. Results indicated that expression of sexual dimorphism in the occipital condylar region within the St. Bride's population is demonstrable but low. Crossvalidated classification accuracy ranged between 69.2 and 76.7%, and sex bias ranged from 0.3 to 9.7%. Therefore, the use of discriminant functions derived from occipital condyles, especially in British skeletal populations, should only be considered in cases of fragmented cranial bases when no other morphognostic or morphometric method can be utilized for sex determination. Am J Phys Anthropol, 2009. © 2008 Wiley-Liss, Inc. [source]

Scale Effects in Markets with Search,

Barbara Petrongolo
Estimates of aggregate matching functions may miss important scale effects in frictional labour markets because of the reactions of job seekers to scale. We estimate a semi-structural model of search and matching on a British sample of unemployed people, testing for scale effects on the probability of receiving an offer and on the distribution of wage offers. We find them only in wage offers but we also find that reservation wages rise to deliver higher post-unemployment wages but not faster matches. So aggregate matching functions should be unaffected by scale but wage equations should be showing them. [source]

Unanswered questions: A preliminary investigation of personality and individual difference predictors of 9/11 conspiracist beliefs

Viren Swami
Given the widespread appeal of conspiratorial beliefs, it is surprising that very little empirical research has examined the psychological variables associated with such beliefs. In the present study, we examined individual and demographic predictors of beliefs in conspiracy theories concerning the September 11, 2001 (9/11) attacks on the World Trade Centre and Pentagon among a representative British sample of 254 women and men. Results of structural equation modelling showed that 9/11 conspiracist beliefs were positively associated with belief in other conspiracy theories, exposure to 9/11 conspiracist ideas, political cynicism, defiance of authority and the Big Five personality factor of Agreeableness. In total, a model including demographics, personality and individual difference variables explained over 50% of the variance in 9/11 conspiracist ideas. The implications of these findings for the literature on conspiracy theories are discussed. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Extending Ellenberg's indicator values to a new area: an algorithmic approach

Mark O. Hill
Summary 1.,Ellenberg's indicator values scale the flora of a region along gradients reflecting light, temperature, continentality, moisture, soil pH, fertility and salinity. They can be used to monitor environmental change. 2.,Ellenberg values can be extended from central Europe, for which they were defined, to nearby parts of Europe. Given a database of quadrat samples, they can be repredicted by a simple algorithm consisting of two-way weighted averaging, followed by local regression. 3.,A database of British samples was assembled from two large surveys. Ellenberg values were repredicted. 4.,Except for the indicator of continentality, the correlation of repredicted and original values was in the range 0·72 (light) to 0·91 (moisture). The continentality indicator could not be adequately repredicted by the algorithm, and is unusable in Britain. 5.,Discrepancies between original and repredicted values can be attributed to various causes, including wrong original values, differing ecological requirements in Britain and central Europe, biased sampling of the British range of habitats, and the occurrence of small plants in shaded or basic microhabitats within well illuminated or predominantly acid quadrats. 6.,The repredicted values were generally reliable, but a small proportion was clearly wrong. Wrong values were due to either inadequate sampling of species' realized niches in Britain or sampling with quadrats that were too large and included species that were not close associates. [source]

Vegetation-environment relationships in Atlantic European calcareous grasslands

J.C. Duckworth
Hill et al. (1994); Tutin et al. (1964,1980) Abstract. The relationship between vegetation and environment was investigated for calcareous grasslands in a region in the west of Spain, France, Britain and Ireland defined by climatic criteria. Vegetation was sampled using objective methods and data collected on soils, land cover, location and management. Climate data were obtained from an available database. Examination of the first axis of vegetation variation as defined by Detrended Correspondence Analysis (DCA) showed a gradient from the Irish and British samples to those from France. The Spanish samples formed a separate group on the second axis. The species composition along the gradients is discussed. Correlations between the vegetation gradients and environmental variables were determined. The strongest correlations with the first DCA axis were for temperature, latitude, soil organic matter, grazing and land cover. The second DCA axis was highly correlated with rainfall, altitude and land cover. The third and fourth DCA axes were more difficult to interpret but appeared to be related to land cover. The results indicate that climate factors are important at this scale, but should not be considered in isolation and that factors relating to land cover and management should also be taken into account. [source]

Evidence for massive clonal growth in the invasive weed Fallopia japonic a (Japanese Knotweed)

Clonal growth in introduced populations of Japanese Knotweed (Fallopia juponica) in Britain was assessed using RAPDs (Randomly Amplified Polymorphic DNA). A total of 150 British samples was analysed for genetic variation using ten arbitrary decamer primers, and compared with data from 16 samples of other introduced populations from Europe and the U.S.A. All samples produced an identical multi-primer RAPD profile. Accepting that RAPD profile identity need not equate to genet identity, based on the sensitivity of these markers for detecting genetic diversity in related taxa and on the absence of male fertile individuals of this species in Britain, we interpret this result as consistent with the presence of a single, exceptionally widespread clone. This clone must represent one of the world's largest vascular plants. [source]