947 research outputs found

    Searches for New Quarks and Leptons Produced in Z-Boson Decay

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    We have searched for events with new-particle topologies in 390 hadronic Z decays with the Mark II detector at the SLAC Linear Collider. We place 95%-confidence-level lower limits of 40.7 GeV/c^2 for the top-quark mass, 42.0 GeV/c^2 for the mass of a fourth-generation charge - 1/3 quark, and 41.3 GeV/c^2 for the mass of an unstable Dirac neutral lepton

    Measurement of Z Decays into Lepton Pairs

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    We present measurements by the Mark II experiment of the ratios of the leptonic partial widths of the Z boson to the hadronic partial width. The results are Γ_(ee)/Γ_(had)=0.037_(-0.012^()+0.016),Γ_(µµ)/Γ_(had)=0.053-_(0.015)^(+0.020), and Γ_(ττ)/Γ_(had)=0.066_(-0.017)^(+0.021), in good agreement with the standard-model prediction of 0.048. From the average leptonic width result, Γ_(ll)/Γ_(had)=0.053_(-0.009)^(+0.010), we derive Γ_(had)=1.56_(-0.24)^(+0.28) GeV. We find for the vector coupling constants of the tau and muon v_τ^2=0.31±0.31_(-0.30)^(+0.43) and v_μ^2=0.05±0.30_(-0.23)^(+0.34)

    Four-year-olds' strategic allocation of resources: Attempts to elicit reciprocation correlate negatively with spontaneous helping

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    Behaviour benefitting others (prosocial behaviour) can be motivated by self-interested strategic concerns as well as by genuine concern for others. Even in very young children such behaviour can be motivated by concern for others, but whether it can be strategically motivated by self-interest is currently less clear. Here, children had to distribute resources in a game in which a rich but not a poor recipient could reciprocate. From four years of age participants strategically favoured the rich recipient, but only when recipients had stated an intention to reciprocate. Six- and eight-year-olds distributed more equally. Children allocating strategically to the rich recipient were less likely to help when an adult needed assistance but was not in a position to immediately reciprocate, demonstrating consistent cross-task individual differences in the extent to which social behaviour is self- versus other-oriented even in early childhood. By four years of age children are capable of strategically allocating resources to others as a tool to advance their own self-interest

    The effect of paternal factors on perinatal and paediatric outcomes : a systematic review and meta-analysis

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    BACKGROUND: Maternal factors, including increasing childbearing age and various life-style factors, are associated with poorer short- and long-term outcomes for children, whereas knowledge of paternal parameters is limited. Recently, increasing paternal age has been associated with adverse obstetric outcomes, birth defects, autism spectrum disorders and schizophrenia in children. OBJECTIVE AND RATIONALE: The aim of this systematic review is to describe the influence of paternal factors on adverse short- and long-term child outcomes. SEARCH METHODS: PubMed, Embase and Cochrane databases up to January 2017 were searched. Paternal factors examined included paternal age and life-style factors such as body mass index (BMI), adiposity and cigarette smoking. The outcome variables assessed were short-term outcomes such as preterm birth, low birth weight, small for gestational age (SGA), stillbirth, birth defects and chromosomal anomalies. Long-term outcome variables included mortality, cancers, psychiatric diseases/disorders and metabolic diseases. The systematic review follows PRISMA guidelines. Relevant meta-analyses were performed. OUTCOMES: The search included 14 371 articles out of which 238 met the inclusion criteria, and 81 were included in quantitative synthesis (meta-analyses). Paternal age and paternal life-style factors have an association with adverse outcome in offspring. This is particularly evident for psychiatric disorders such as autism, autism spectrum disorders and schizophrenia, but an association is also found with stillbirth, any birth defects, orofacial clefts and trisomy 21. Paternal height, but not BMI, is associated with birth weight in offspring while paternal BMI is associated with BMI, weight and/or body fat in childhood. Paternal smoking is found to be associated with an increase in SGA, birth defects such as congenital heart defects, and orofacial clefts, cancers, brain tumours and acute lymphoblastic leukaemia. These associations are significant although moderate in size, with most pooled estimates between 1.05 and 1.5, and none exceeding 2.0. WIDER IMPLICATIONS: Although the increased risks of adverse outcome in offspring associated with paternal factors and identified in this report represent serious health effects, the magnitude of these effects seems modest.Peer reviewe

    Suppression of High-p_T Neutral Pion Production in Central Pb+Pb Collisions at sqrt{s_NN} = 17.3 GeV Relative to p+C and p+Pb Collisions

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    Neutral pion transverse momentum spectra were measured in p+C and p+Pb collisions at sqrt{s_NN} = 17.4 GeV at mid-rapidity 2.3 < eta_lab < 3.0 over the range 0.7< p_T < 3.5 GeV/c. The spectra are compared to pi0 spectra measured in Pb+Pb collisions at sqrt{s_NN} = 17.3 GeV in the same experiment. For a wide range of Pb+Pb centralities (N_part < 300) the yield of pi0's with p_T > 2 GeV/c is larger than or consistent with the p+C or p+Pb yields scaled with the number of nucleon-nucleon collisions (N_coll), while for central Pb+Pb collisions with N_part > 350 the pi0 yield is suppressed.Comment: 5 pages, 4 figure

    Mental health problems in youths committed to juvenile institutions: prevalences and treatment needs

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    Many international studies show that adolescents in coercive institutional care display high prevalences of mental disorders, especially in the form of disruptive behavior disorders [including attention-deficit/hyperactivity disorder (AD/HD), oppositional defiant disorder, and conduct disorder], anxiety disorders, and mood disorders. High degrees of overlap across mental disorders have also been reported. In addition, institutionalized adolescents are often traumatized. Despite this well-documented psychiatric morbidity, the mental health care needs of detained adolescents are often overlooked. The main objective of this study is to assess prevalences of psychiatric disorders, results of intelligence tests, and previous contacts with child and adolescent psychiatric services among adolescents in institutional care. DSM-IV diagnoses, mental health contacts, substance abuse, neurocognitive abilities, and school performance were registered in 100 adolescents (92 boys, 8 girls) aged 12–19 years (mean age 16.0; SD ± 1.5) consecutively committed to Swedish juvenile institutions between 2004 and 2007. At least one psychiatric disorder was diagnosed in 73% of the subjects: 48% met DSM-IV diagnostic criteria for AD/HD, 17% for an autism spectrum disorder, and 10% for a mental retardation. The collapsed prevalence for psychiatric disorders requiring specialist attention was 63%. Our data indicate that systematic diagnostic procedures are crucial in the treatment planning for institutionalized adolescents. Adequate treatment strategies need to be designed and implemented to meet the extensive mental health care needs of this vulnerable population

    A primary care, multi-disciplinary disease management program for opioid-treated patients with chronic non-cancer pain and a high burden of psychiatric comorbidity

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    BACKGROUND: Chronic non-cancer pain is a common problem that is often accompanied by psychiatric comorbidity and disability. The effectiveness of a multi-disciplinary pain management program was tested in a 3 month before and after trial. METHODS: Providers in an academic general medicine clinic referred patients with chronic non-cancer pain for participation in a program that combined the skills of internists, clinical pharmacists, and a psychiatrist. Patients were either receiving opioids or being considered for opioid therapy. The intervention consisted of structured clinical assessments, monthly follow-up, pain contracts, medication titration, and psychiatric consultation. Pain, mood, and function were assessed at baseline and 3 months using the Brief Pain Inventory (BPI), the Center for Epidemiological Studies-Depression Scale scale (CESD) and the Pain Disability Index (PDI). Patients were monitored for substance misuse. RESULTS: Eighty-five patients were enrolled. Mean age was 51 years, 60% were male, 78% were Caucasian, and 93% were receiving opioids. Baseline average pain was 6.5 on an 11 point scale. The average CESD score was 24.0, and the mean PDI score was 47.0. Sixty-three patients (73%) completed 3 month follow-up. Fifteen withdrew from the program after identification of substance misuse. Among those completing 3 month follow-up, the average pain score improved to 5.5 (p = 0.003). The mean PDI score improved to 39.3 (p < 0.001). Mean CESD score was reduced to 18.0 (p < 0.001), and the proportion of depressed patients fell from 79% to 54% (p = 0.003). Substance misuse was identified in 27 patients (32%). CONCLUSIONS: A primary care disease management program improved pain, depression, and disability scores over three months in a cohort of opioid-treated patients with chronic non-cancer pain. Substance misuse and depression were common, and many patients who had substance misuse identified left the program when they were no longer prescribed opioids. Effective care of patients with chronic pain should include rigorous assessment and treatment of these comorbid disorders and intensive efforts to insure follow up
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