209 research outputs found

    Identification of Tundra Land Cover near Teshekpuk Lake, Alaska Using SPOT Satellite Data

    Get PDF
    Tundra vegetation in the Teshekpuk Lake area of the Alaskan Arctic Coastal Plain was mapped to assess distribution and abundance of waterfowl habitats. Three SPOT satellite scenes were acquired and registered to a 20 m Universal Transverse Mercator grid. Two clustering techniques were used to develop statistical parameters by which the SPOT data were spectrally classified. A maximum likelihood algorithm that correlated spectral classes with land cover types was applied to the SPOT data. Field data were used to assist in spectral class labeling and vegetation descriptions. Twelve cover classes were mapped. The most common type was moist sedge meadow tundra (13.5%); the least common was moss/peat shoreline (0.2%). The moss/peat shoreline type, important to moulting geese and other waterfowl, was spectrally identified using supervised clustering techniques. All other land cover types were identified using unsupervised clustering techniques. Cover classes were described, and a tundra landscape profile produced.Key words: tundra land cover mapping, SPOT satellite data, Teshekpuk Lake, AlaskaOn a dressé une carte de la végétation de toundra dans la région du lac Teshekpuk de la plaine côtière arctique de l'Alaska afin d'évaluer la distribution et l'abondance de l'habitat de la sauvagine. On s'est procuré trois scènes prises par le satellite SPOT, qu'on a alignées sur un quadrillage de 20 m de la projection transverse universelle de Mercator. On a utilisé deux techniques d'agrégation pour élaborer des paramètres statistiques grâce auxquels on a classé en fonction du spectre les données provenant du SPOT. On a appliqué aux données du SPOT un algorithme de vraisemblance maximale corrélant les classes spectrales avec les types de couvert végétal. On a utilisé des données de terrain pour aider à nommer les classes spectrales et à décrire la végétation. On a cartographié 12 classes de couvert végétal, le plus commun étant la toundra de prairie à laîches humide (13,5 p. cent), et le moins abondant étant le littoral de mousse/tourbe (0,2 p. cent). On s'est servi de techniques d'agrégation dirigées pour identifier en fonction du spectre le type de mousse/tourbe, important pour les oies en période de mue et autre sauvagine. Tous les autres types de couvert végétal ont été identifiés à l'aide de techniques d'agrégation non dirigées. On a décrit les classes de couvert et établi un profil de paysage de toundra.Mots clés: cartographie du couvert végétal de la toundra, données provenant du satellite SPOT, lac Teshekpuk, Alask

    Identification of Tundra Land Cover near Teshekpuk Lake, Alaska Using SPOT Satellite Data

    Get PDF
    ABSTRACT. Tundra vegetation in the Teshekpuk Lake area of the Alaskan Arctic Coastal Plain was mapped to assess distribution and abundance of waterfowl habitats. Three SPOT satellite scenes were acquired and registered to a 20 m Universal Transverse Mercator grid. Two clustering techniques were used to develop statistical parameters by which the SPOT data were spectrally classified. A maximum likelihood algorithm that correlated spectral classes with land cover types was applied to the SPOT data. Field data were used to assist in spectral class labeling and vegetation descriptions. Twelve cover classes were mapped. The most common type was moist sedge meadow tundra (13.5%); the least common was moss/peat shoreline (0.2%). The moss/peat shoreline type, important to moulting geese and other waterfowl, was spectrally identified using supervised clustering techniques. All other land cover types were identified using unsupervised clustering techniques. Cover classes were described, and a tundra landscape profile produced. Key words: tundra land cover mapping, SPOT satellite data, Teshekpuk Lake, Alaska RÉSUMÉ. On a dressé une carte de la végétation de toundra dans la région du lac Teshekpuk de la plaine côtière arctique de l’Alaska afin d’évaluer la distribution et l’abondance de l’habitat de la sauvagine. On s’est procuré trois scènes prises par le satellite SPOT, qu’on a alignées sur un quadrillage de 20 m de la projection transverse universelle de Mercator. On a utilisé deux techniques d’agrégation pour élaborer des paramètres statistiques grâce auxquels on a classé en fonction du spectre les données provenant du SPOT. On a appliqué aux données du SPOT un algorithme de vraisemblance maximale corrélant les classes spectrales avec les types de couvert végétal. On a utilisé des données de terrain pour aider à nommer les classes spectrales et à décrire la végétation. On a cartographié 12 classes de couvert végétal

    The hierarchical structure of DSM-5 pathological personality traits

    Full text link
    A multidimensional trait system has been proposed for representing personality disorder (PD) features in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) to address problematic classification issues such as comorbidity. In this model, which may also assist in providing scaffolding for the underlying structure of major forms of psychopathology more generally, 25 primary traits are organized by 5 higher order dimensions: Negative Affect, Detachment, Antagonism, Disinhibition, and Psychoticism. We examined (a) the generalizability of the structure proposed for DSM-5 PD traits, and (b) the potential for an integrative hierarchy based upon DSM-5 PD traits to represent the dimensions scaffolding psychopathology more generally. A large sample of student participants (N = 2,461) completed the Personality Inventory for DSM-5, which operationalizes the DSM-5 traits. Exploratory factor analysis replicated the initially reported 5-factor structure, as indicated by high factor congruencies. The 2-, 3-, and 4-factor solutions estimated in the hierarchy of the DSM-5 traits bear close resemblance to existing models of common mental disorders, temperament, and personality pathology. Thus, beyond the description of individual differences in personality disorder, the trait dimensions might provide a framework for the metastructure of psychopathology in the DSM-5 and the integration of a number of ostensibly competing models of personality trait covariation

    An Interpersonal Analysis of Pathological Personality Traits in DSM-5

    Full text link
    The proposed changes to the personality disorder section of the Diagnostic and Statistical Manual of Mental Disorders (5th ed.) places an increased focus on interpersonal impairment as one of the defining features of personality psychopathology. In addition, a proposed trait model has been offered to provide a means of capturing phenotypic variation on the expression of personality disorder. In this study, the authors subject the proposed DSM-5 traits to interpersonal analysis using the Inventory of Interpersonal Problems–Circumplex scales via the structural summary method for circumplex data. DSM-5 traits were consistently associated with generalized interpersonal dysfunction suggesting that they are maladaptive in nature, the majority of traits demonstrated discriminant validity with prototypical and differentiated interpersonal problem profiles, and conformed well to a priori hypothesized associations. These results are discussed in the context of the DSM-5 proposal and contemporary interpersonal theory, with a particular focus on potential areas for expansion of the DSM-5 trait model

    Demographic and behavioural correlates of energy drink consumption

    Get PDF
    Abstract Objective: Energy drinks are consumed for a variety of reasons, including to boost mental alertness and energy. We assessed associations between demographic factors and various high-risky behaviours with energy drink consumption as they may be linked to adverse health events. Design: We conducted cross-sectional analysis including basic descriptive and multivariable-adjusted logistic regression analyses to characterise demographic and behavioural factors (including diet quality, binge drinking and illicit drug use, among others obtained via questionnaires) in relation to energy drink consumption. Setting: We used data from two large US-based cohorts. Participants: 46 390 participants from Nurses’ Health Study 3 (NHS3, n 37 302; ages 16–31) and Growing Up Today Study (GUTS, n 9088, ages 20–55). Results: Of the 46 390 participants, 13·2 % reported consuming ≥ 1 energy drink every month. Several risky behaviours were associated with energy drink use, including illegal drug use (pooled OR, pOR: 1·45, 95 % CI: 1·16, 1·81), marijuana use (pOR: 1·49, 95 % CI: 1·28, 1·73), smoking (pOR: 1·88. 95 % CI: 1·55, 2·29), tanning bed use (pOR: 2·31, 95 % CI: 1·96, 2·72) and binge drinking (pOR: 2·53, 95 % CI: 2·09, 3·07). Other factors, such as high BMI, e-cigarette use and poor diet quality were found to be significantly associated with higher energy drink consumption (P values < 0·001). Conclusions: Our findings show that energy drink consumption and high-risk behaviours may be related, which could potentially serve as not only as a talking point for providers to address in outreach and communications with patients, but also a warning sign for medical and other health practitioners

    Profiles of physical, emotional and psychosocial wellbeing in the Lothian birth cohort 1936

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Physical, emotional, and psychosocial wellbeing are important domains of function. The aims of this study were to explore the existence of separable groups among 70-year olds with scores representing physical function, perceived quality of life, and emotional wellbeing, and to characterise any resulting groups using demographic, personality, cognition, health and lifestyle variables.</p> <p>Methods</p> <p>We used latent class analysis (LCA) to identify possible groups.</p> <p>Results</p> <p>Results suggested there were 5 groups. These included High (n = 515, 47.2% of the sample), Average (n = 417, 38.3%), and Poor Wellbeing (n = 37, 3.4%) groups. The two other groups had contrasting patterns of wellbeing: one group scored relatively well on physical function, but low on emotional wellbeing (Good Fitness/ Low Spirits,n = 60, 5.5%), whereas the other group showed low physical function but relatively well emotional wellbeing (Low Fitness/Good Spirits, n = 62, 5.7%). Salient characteristics that distinguished all the groups included smoking and drinking behaviours, personality, and illness.</p> <p>Conclusions</p> <p>Despite there being some evidence of these groups, the results also support a largely one-dimensional construct of wellbeing in old age—for the domains assessed here—though with some evidence that some individuals have uneven profiles.</p

    Approach, avoidance, and their conflict: the problem of anchoring

    Get PDF
    To understand the neurobiology of indi-vidual differences in approach and avoid-ance behavior, we must anchor constructs at the behavioral level to the long-term global sensitivities of the neural systems that give rise to the observed stable pat-terns of behavior. We will argue that this requires not only appropriate data at both the neural and behavioral levels but also appropriate account to be taken of inter-actions at the intervening level of the conceptual nervous system (Hebb, 1949; Gray, 1975). In particular, in accounting for approach and avoidance behavior we must include consideration of the distinc

    Homotypic and heterotypic psychopathological continuity: a child cohort study

    Get PDF
    Background: Heterotypic psychopathological continuity (i.e. one disorder predicting another at a later time point) contradicts the conventional view that psychiatric disorders are discrete, static entities. Studying this phenomenon may help to tease out the complex mechanisms that underpin psychiatric comorbidity. To date, no studies have explicitly compared heterotypic effects within and across higher order dimensions of psychopathology. // Methods: Patterns of homotypic and heterotypic psychopathological continuity were examined using cohort data from the Avon Longitudinal Study of Parents and Children (ALSPAC, N = 4815). Eight common psychiatric disorders were assessed at age 7.5 and again at age 14 years using the maternal report version of the Development and Well-Being Assessment (DAWBA). Cross-lagged models were used to compare patterns of homotypic and heterotypic continuity within and across three higher order dimensions of psychopathology; internalizing-fear, internalizing-distress, and externalizing. // Results: Homotypic continuity was universal. Considerable heterotypic continuity was observed even after controlling for homotypic continuity and the presence of all disorders at baseline. Heterotypic continuity was more common within higher order dimensions, but a number of significant cross-dimension effects were observed, with ADHD acting as a strong predictor of subsequent internalizing disorders. // Conclusions: Heterotypic continuity may reflect elements of shared aetiology, or local-level interactions between disorders

    Childhood characteristics and participation in Scottish Mental Survey 1947 6-Day Sample Follow-ups: Implications for participation in aging studies

    Get PDF
    Given the ‘graying’ of especially the populations of most western nations, studies of factors contributing to well-being in later life are important and common, and it is important to their accuracy that they be based on samples representative of the populations in the relevant age groups. There is general awareness that several characteristics such as sex, socioeconomic status, cognitive ability and personality are associated with study participation, but many researchers assume that this reflects life circumstances at time of recruitment rather than inherent individual characteristics that shape those circumstances throughout people’s lives. The Scottish Mental Survey 1947 6-Day Sample Follow-Up Study offered an unusual opportunity to test this assumption, as follow-up study participation data were available both in young adulthood and at age 77. Participation at age 77 was dramatically restricted relative to that in young adulthood. Cognitive abilities and a composite of conscientiousness-related variables independent of cognitive ability assessed in childhood predicted participation at young ages, but much more strongly at older ages. Evidence was available that these results were not specific to the recruiting and assessment methods used in this study. This suggests that participation in studies of aging is a function not just of contemporaneous circumstances but also of early-life cognitive and personality characteristics that have shaped those circumstances.
    corecore