2,958 research outputs found

    Aurore, l’enfant martyre. Essai sur la violence faite aux enfants

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    Ressortir de la petite histoire récente du Québec rural ce drame-symbole de l'enfant martyre que fut Aurore Gagnon : cela n'est pas sans provoquer, dans une perspective systémique en tout cas, des réflexions et une mise en perspective qui vont bien au-delà des généralités auxquelles ce genre de récit donne habituellement lieu. On voit bien, par exemple, que le comportement de la belle-mère d'Aurore, pour aberrant qu'il soit, n'en est pas moins surdéterminé par un ensemble de circonstances du milieu. Les conditions sociales d'aujourd'hui ne ressemblent guère à celles de naguère ; il n'empêche que, certains facteurs étant réunis, les enfants, qui sont pourtant notre bien le plus précieux, continuent d'être en danger en présence de leurs propres parents.This article draws on the sad story of Aurore Gagnon, a battered child raised in rural Québec and whose turmoil was dramatized on film. By elaborating on this symbol, the author is able to generate, at least in a systemic perspective, a number of issues and outlooks that go far beyond the generalities usually associated with this tale. For instance, there is ample evidence showing that the behaviour of Aurore's stepmother, aberrant as it may be, is largely caused by a set of environmental circumstances. Of course, today's social conditions hardly resemble those of the past. Yet, given the conjunctions of certain factors, children, who are nevertheless our most valuable asset, continue to be in danger in the presence of their very own parents

    State and parameter estimation techniques for stochastic systems

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    This thesis documents research undertaken on state and parameter estimationtechniques for stochastic systems in a maintenance context. Two individual problemscenarios are considered. For the first scenario, we are concerned with complexsystems and the research involves an investigation into the ability to identify andquantify the occurrence of fault injection during routine preventive maintenanceprocedures. This is achieved using an appropriate delay time modelling specificationand maximum-likelihood parameter estimation techniques. The delay time model ofthe failure process is parameterised using objective information on the failure timesand the number of faults removed from the system during preventive maintenance.We apply the proposed modelling and estimation process to simulated data sets in anattempt to recapture specified parameters and the benefits of improving maintenanceprocesses are demonstrated for the particular example. We then extend the modellingof the system in a predictive manner and combine it with a stochastic filteringapproach to establish an adaptive decision model. The decision model can be used toschedule the subsequent maintenance intervention during the course of anoperational cycle and can potentially provide an improvement on fixed intervalmaintenance policies.The second problem scenario considered is that of an individual component subjectto condition monitoring such as, vibration analysis or oil-based contamination. Theresearch involves an investigation into techniques that utilise condition informationthat we assume is related stochastically to the underlying state of the component,taken here to be the residual life. The techniques that we consider are theproportional hazards model and a probabilistic stochastic filtering approach. Weinvestigate the residual life prediction capabilities of the two techniques and construct relevant replacement decision models. The research is then extended toconsider multiple indicators of condition obtained simultaneously at monitoringpoints. We conclude with a brief investigation into the use of stochastic filteringtechniques in specific scenarios involving limited computational power and variableunderlying relationships between the monitored information and the residual life

    Schizotypy, childhood trauma and brain morphometry

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    Background: Childhood trauma confers risk for psychosis and is associated with increased ‘schizotypy’ (a multi-dimensional construct reflecting risk for psychosis in the general population). Structural brain alterations are associated with both childhood trauma and schizotypy, but the potential role of trauma exposure in moderating associations between schizotypy and brain morphology has yet to be determined. Methods: Participants were 160 healthy individuals (mean age: 40.08 years, SD = 13.64, range 18–64; 52.5% female). Childhood trauma exposure was assessed using the Childhood Adversity Questionnaire, and schizotypy was assessed using the Schizotypal Personality Questionnaire. Univariate voxel-based morphometry and multivariate analyses of grey matter volume covariation (GMC; derived from independent component analysis) were performed to determine the main effects of schizotypy, trauma exposure and their interaction on these indices of grey matter volume. Moderation analyses were performed following significant interaction. Results: Levels of schizotypy, in particular the Cognitive-Perceptual and Interpersonal dimensions, were negatively associated with GMC in the striatum, the hippocampus/parahippocampal gyrus, thalamus and insulae. Trauma exposure was negatively associated with GMC of the middle frontal gyrus and parietal lobule, while negatively associated with GMC in the cerebellum. Levels of schizotypy (total scores, and the cognitive-perceptual dimension) were negatively associated with striatal GMC in individuals not exposed to trauma, but not in those exposed to trauma. Conclusions: Schizotypy and childhood trauma were independently associated with changes of grey matter in brain regions critical for cognition and social cognition. In individuals not exposed to trauma, increased schizotypy was associated with decreased striatal and limbic grey matter

    Self-harm in a primary care cohort of older people: incidence, clinical management, and risk of suicide and other causes of death

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    BACKGROUND: Self-harm is a major risk factor for suicide, with older adults (older than 65 years) having reportedly greater suicidal intent than any other age group. With the aging population rising and paucity of research focus in this age group, the extent of the problem of self-harm needs to be established. In a primary care cohort of older adults we aimed to investigate the incidence of self-harm, subsequent clinical management, prevalence of mental and physical diagnoses, and unnatural-cause mortality risk, including suicide. METHODS: The UK Clinical Practice Research Datalink contains anonymised patient records from general practice that routinely capture clinical information pertaining to both primary and secondary care services. We identified 4124 adults aged 65 years and older with a self-harm episode ascertained from Read codes recorded during 2001-14. We calculated standardised incidence and in 2854 adults with at least 12 months follow-up examined the frequency of psychiatric referrals and prescription of psychotropic medication after self-harm. We estimated prevalence of mental and physical illness diagnoses before and after self-harm and, using Cox regression in a matched cohort, we examined cause-specific mortality risks. FINDINGS: Overall incidence of self-harm in older adults aged 65 years and older was 4·1 per 10 000 person-years with stable gender-specific rates observed over the 13-year period. After self-harm, 335 (11·7%) of 2854 adults were referred to mental health services, 1692 (59·3%) were prescribed an antidepressant, and 336 (11·8%) were prescribed a tricyclic antidepressant (TCA). Having a diagnosed previous mental illness was twice as prevalent in the self-harm cohort as in the comparison cohort (prevalence ratio 2·10 [95% CI 2·03-2·17]) and with a previous physical health condition prevalence was 20% higher in the self-harm cohort compared to the comparison cohort (1·20 [1·17-1·23]). Adults from the self-harm cohort (n=2454) died from unnatural causes an estimated 20 times more frequently than the comparison cohort (n=48 921) during the first year. A markedly elevated risk of suicide (hazard ratio 145·4 [95% CI 53·9-392·3]) was observed in the self-harm cohort. INTERPRETATION: Within primary care, we have identified a group of older adults at high risk from unnatural death, particularly within the first year of self-harm. We have highlighted a high frequency of prescription of TCAs, known to be potentially fatally toxic in overdose. We emphasise the need for early intervention, careful alternative prescribing, and increased support when older adults consult after an episode of self-harm and with other health conditions. FUNDING: National Institute for Health Research Greater Manchester Patient Safety Translational Research Centre

    Relationships between parental mental illness and/or offending and offspring contact with the police in childhood: Findings from a longitudinal record-linkage study

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    Background: Parental offending and mental illness are associated with an increased risk of criminal behaviour in offspring during adolescence and adulthood, but the impact of such problems on younger children, including children's experiences of victimisation, is less well known. Aim: To investigate the associations between parental offending and mental illness recorded prior to their offspring's age of 5 years and their offspring's contact with police as a ‘person of interest’, ‘victim’ or ‘witness’ between ages 5 and 13 years. Methods: Our sample consisted of 72,771 children and their parents drawn from the New South Wales Child Development Study, an Australian longitudinal population-based record linkage study. Logistic regression analyses were conducted to examine associations between parental factors and offspring's police contact. Separate models examined the relationships between maternal or paternal offending and mental illness, as well as the combination among either or both parents, as the independent variables, and their child's police contact as the dependent variable. Results: Parental offending and mental illness were each individually associated with indices of police contact among offspring. Stronger associations were observed when both offending and mental illness were present together (in either parent, or when one parent had both exposures). Stronger associations were evident for mothers with both factors across all offspring police contact types, relative to fathers with both factors, in fully adjusted models; that is, children of mothers with both factors were over four times as likely to have contact with police as a ‘person of interest’ (OR = 4.29; 95% CI = 3.75–4.92) and over three times as likely to have contact as a victim (OR = 3.35; 95% CI = 3.01–3.74) or witness (OR = 3.58; 95% CI = 3.03–4.24), than children whose mothers had no history of offending or mental illness. Conclusions: Children with a parental history of offending and mental illness in early life are at an increased likelihood of early police contact as young as 5–13 years of age; it is vital that this is taken as a signal to help them and their affected families according to need

    Cumulative Environmental Risk in Early Life: Associations With Schizotypy in Childhood

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    BACKGROUND AND HYPOTHESIS: Psychotic disorders are associated with a growing number of recognized environmental exposures. Cumulative exposure to multiple environmental risk factors in childhood may contribute to the development of different patterns of schizotypy evident in early life. Hypotheses were that distinct profiles of schizotypy would have differential associations with a cumulative score of environmental risk factors. STUDY DESIGN: We prospectively examined the relationship between 19 environmental exposures (which had demonstrated replicated associations with psychosis) measured from the prenatal period through to age 11 years, and 3 profiles of schizotypy in children (mean age = 11.9 years, n = 20 599) that have been established in population data from the New South Wales-Child Development Study. Multinomial logistic regression was used to examine associations between membership in each of 3 schizotypy profiles (true schizotypy, introverted schizotypy, and affective schizotypy) and exposure to a range of 19 environmental risk factors for psychosis (both individually and summed as a cumulative environmental risk score [ERS]), relative to children showing no risk. RESULTS: Almost all environmental factors were associated with at least 1 schizotypy profile. The cumulative ERS was most strongly associated with the true schizotypy profile (OR = 1.61, 95% CI = 1.52-1.70), followed by the affective (OR = 1.33, 95% CI = 1.28-1.38), and introverted (OR = 1.32, 95% CI = 1.28-1.37) schizotypy profiles. CONCLUSIONS: Consistent with the cumulative risk hypothesis, results indicate that an increased number of risk exposures is associated with an increased likelihood of membership in the 3 schizotypy profiles identified in middle childhood, relative to children with no schizotypy profile

    Theory of Multidimensional Solitons

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    We review a number of topics germane to higher-dimensional solitons in Bose-Einstein condensates. For dark solitons, we discuss dark band and planar solitons; ring dark solitons and spherical shell solitons; solitary waves in restricted geometries; vortex rings and rarefaction pulses; and multi-component Bose-Einstein condensates. For bright solitons, we discuss instability, stability, and metastability; bright soliton engineering, including pulsed atom lasers; solitons in a thermal bath; soliton-soliton interactions; and bright ring solitons and quantum vortices. A thorough reference list is included.Comment: review paper, to appear as Chapter 5a in "Emergent Nonlinear Phenomena in Bose-Einstein Condensates: Theory and Experiment," edited by P. G. Kevrekidis, D. J. Frantzeskakis, and R. Carretero-Gonzalez (Springer-Verlag
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