2,332 research outputs found
On a certain class of multiplicative functions
Let Ï0, Ï1, Ï2, ⊠be the sequence of all Dirichlet characters (in which the principal character Ï0 occurs only once), ordered with increasig moduli. Define, for a sequence (αk)kΔN of real numbers (αkâ0 for jââ, sufficiently quickly) the multiplicative function f byânf(n)ns=ζâ1(s)âk=1â(L(s,Ïk))akIt is the aim of the paper to construct sequences (αk) such that the following statements are equivalento(i)ânâ©œxf(n)=O(x1/2+É)for every É > 0,(ii)the Riemann hypothesis is true for all function L(s, Ï)
Poor attention rather than hyperactivity/impulsivity predicts academic achievement in very preterm and full-term adolescents
Background: Very preterm (VP) children are at particular risk for attention deficit/hyperactivity disorder (ADHD) of the inattentive subtype. It is unknown whether the neurodevelopmental pathways to academic underachievement are the same as in the general population. This study investigated whether middle childhood attention or hyperactivity/impulsivity problems are better predictors of VP adolescents' academic achievement.
Method: In a geographically defined prospective whole-population sample of VP (<32 weeks gestation) and/or very low birth weight (<1500 g birth weight) (VLBW/VP; n = 281) and full-term control children (n = 286) in South Germany, ADHD subtypes were assessed at 6 years 3 months and 8 years 5 months using multiple data sources. Academic achievement was assessed at 13 years of age.
Results: Compared with full-term controls, VLBW/VP children were at higher risk for ADHD inattentive subtype [6 years 3 months: odds ratio (OR) 2.8, p < 0.001; 8 years 5 months: OR 1.7, p = 0.020] but not for ADHD hyperactive-impulsive subtype (6 years 3 months: OR 1.4, p = 0.396; 8 years 5 months: OR 0.9, p = 0.820). Childhood attention measures predicted academic achievement in VLBW/VP and also full-term adolescents, whereas hyperactive/impulsive behaviour did not.
Conclusions: Attention is an important prerequisite for learning and predicts long-term academic underachievement. As ADHD inattentive subtype and cognitive impairments are frequent in VLBW/VP children, their study may help to identify the neurofunctional pathways from early brain development and dysfunction to attention problems and academic underachievement
Summary of the COSY-11 Measurements of Hyperon Production
The studies of hyperon production performed at COSY-11 are summarized. The
results of the experiments in the reaction channels pp-->pK+Lambda,
pp-->pK+Sigma0, and pp-->nK+Sigma+ are shown. Excitation functions
fromthreshold up to about 90MeV excess energies have been evaluated with high
precision for the Lambda and Sigma0 production. The Lambdap and Sigma0p final
state interactions were extracted. The Sigma+ production was measured at 13 and
60 MeV excess energies.Comment: 8 pages, 4 figures, Talk given at Symposium on Meson Physics at
COSY-11 and WASA-at-COSY, Cracow, Poland, 17-22 Jun 200
Developmental risk for children born prematurely
In the average sized primary classroom, there is a chance to there will be two children who were born preterm, with numbers increasing, how well do we understand how this might affect their learning
Human health risks due to consumption of chemically contaminated fishery products.
A small proportion of fishery products contaminated with appreciable amounts of potentially hazardous inorganic and organic contaminants from natural and environmental sources seem to pose the greatest potential for toxicity to consumers of fishery products in the United States. Health risks due to chemicals (e.g., modest changes in the overall risk of cancer, subtle deficits of neurological development in fetuses and children) are difficult to measure directly in people exposed to low levels. Immunocompetence may increase cancer risk. Inferences about the potential magnitude of these problems must be based on the levels of specific chemical present, observations of human populations and experimental animals exposed to relatively high doses, and theories about the likely mechanisms of action of specific intoxicants and the population distribution of sensitivity of human exposure. Lognormal distributions were found to provide good descriptions of the pattern of variation of contaminant concentrations among different species and geographic areas; this variability offers a solution for reduction of exposure through restricting harvest of aquatic animals from certain sites and by excluding certain species. Available information suggest that risks are not generally of high magnitude; nevertheless, their control will significantly improve public health.(ABSTRACT TRUNCATED AT 250 WORDS
School mobility and prospective pathways to psychotic-like symptoms in early adolescence: a prospective birth cohort study
OBJECTIVE: Social adversity and urban upbringing increase the risk of psychosis. We tested the hypothesis that these risks may be partly attributable to school mobility and examined the potential pathways linking school mobility to psychotic-like symptoms. METHOD: A community sample of 6,448 mothers and their children born between 1991 and 1992 were assessed for psychosocial adversities (i.e., ethnicity, urbanicity, family adversity) from birth to 2 years, school and residential mobility up to 9 years, and peer difficulties (i.e., bullying involvement and friendship difficulties) at 10 years. Psychotic-like symptoms were assessed at age 12 years using the Psychosis-like Symptoms Interview (PLIKSi). RESULTS: In regression analyses, school mobility was significantly associated with definite psychotic-like symptoms (odds ratio [OR] =1.60; 95% CI =1.07-2.38) after controlling for all confounders. Within path analyses, school mobility (probit coefficient [ÎČ] = 0.108; p = .039), involvement in bullying (ÎČ = 0.241; p < .001), urbanicity (ÎČ = 0.342; p = .016), and family adversity (ÎČ = 0.034; p < .001) were all independently associated with definite psychotic-like symptoms. School mobility was indirectly associated with definite psychotic-like symptoms via involvement in bullying (ÎČ = 0.018; p = .034). CONCLUSIONS: School mobility is associated with increased risk of psychotic-like symptoms, both directly and indirectly. The findings highlight the potential benefit of strategies to help mobile students to establish themselves within new school environments to reduce peer difficulties and to diminish the risk of psychotic-like symptoms. Awareness of mobile students as a possible high-risk population, and routine inquiry regarding school changes and bullying experiences, may be advisable in mental health care settings
Investigating whether adverse prenatal and perinatal events are associated with non-clinical psychotic symptoms at age 12 years in the ALSPAC birth cohort
Background. Non-clinical psychosis-like symptoms (PLIKS) occur in about 15% of the population. It is not clear
whether adverse events during early development alter the risk of developing PLIKS. We aimed to examine whether
maternal infection, diabetes or pre-eclampsia during pregnancy, gestational age, perinatal cardiopulmonary resuscitation
or 5-min Apgar score were associated with development of psychotic symptoms during early adolescence.
Method. A longitudinal study of 6356 12-year-old adolescents who completed a semi-structured interview for
psychotic symptoms in the Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort. Prenatal and
perinatal data were obtained from obstetric records and maternal questionnaires completed during pregnancy.
Results. The presence of definite psychotic symptoms was associated with maternal infection during pregnancy
[adjusted odds ratio (OR) 1.44, 95% confidence interval (CI) 1.11â1.86, p=0.006], maternal diabetes (adjusted OR 3.43,
95% CI 1.14â10.36, p=0.029), need for resuscitation (adjusted OR 1.50, 95% CI 0.97â2.31, p=0.065) and 5-min Apgar
score (adjusted OR per unit decrease 1.30, 95% CI 1.12â1.50, p<0.001). None of these associations were mediated by
childhood IQ score. Most associations persisted, but were less strong, when including suspected symptoms as part of
the outcome. There was no association between PLIKS and gestational age or pre-eclampsia.
Conclusions. Adverse events during early development may lead to an increased risk of developing PLIKS.
Although the status of PLIKS in relation to clinical disorders such as schizophrenia is not clear, the similarity
between these results and findings reported for schizophrenia indicates that future studies of PLIKS may help us to
understand how psychotic experiences and clinical disorders develop throughout the life-course
Experimental Test of Momentum Cooling Model Predictions at COSY and Conclusions for WASA and HESR
The High-Energy Storage Ring (HESR) of the future International Facility for
Antiproton and Ion Research (FAIR) at GSI in Darmstadt is planned as an
anti-proton cooler ring in the momentum range from 1.5 to 15 GeV/c. An
important and challenging feature of the new facility is the combination of
highly dense phase space cooled beams with internal targets. A detailed
numerical and analytical approach to the Fokker-Planck equation for
longitudinal filter cooling including the beam - target interaction has been
carried out to demonstrate the stochastic cooling capability. To gain
confidence in the model predictions a series of experimental stochastic cooling
studies with the internal target ANKE at COSY have been carried out. A
remarkable agreement between model and experiment was achieved. On this basis
longitudinal stochastic cooling simulations were performed to predict the
possibilities and limits of cooling when the newly installed WASA Pellet-target
is operated.Comment: 17 pages, 11 figures, Talk given at Symposium on Meson Physics at
COSY-11 and WASA-at-COSY, Cracow, Poland, 17-22 Jun 200
Pathways between childhood victimization and psychosis-like symptoms in the ALSPAC Birth Cohort
Background: Several large population-based studies have demonstrated associations between adverse childhood experiences and later development of psychotic symptoms. However, little attention has been paid to the mechanisms involved in this pathway and the few existing studies have relied on cross-sectional assessments. Methods: Prospective data on 6692 children from the UK Avon Longitudinal Study of Parents and Children (ALSPAC) were used to address this issue. Mothers reported on childrenâs exposure to harsh parenting and domestic violence in early childhood, and children self-reported on bullying victimization prior to 8.5 years. Presence of childrenâs anxiety at 10 years and their depressive symptoms at 9 and 11 years were ascertained from mothers, and children completed assessments of self-esteem and locus of control at 8.5 years. Children were interviewed regarding psychotic symptoms at a mean age of 12.9 years. Multiple mediation analysis was performed to examine direct and indirect effects of each childhood adversity on psychotic symptoms. Results: The association between harsh parenting and psychotic symptoms was fully mediated by anxiety, depressive symptoms, external locus of control, and low self-esteem. Bullying victimization and exposure to domestic violence had their associations with psychotic symptoms partially mediated by anxiety, depression, locus of control, and self-esteem. Similar results were obtained following adjustment for a range of confounders and when analyses were conducted for boys and girls separately. Conclusions: These findings tentatively suggest that specific cognitive and affective difficulties in childhood could be targeted to minimize the likelihood of adolescents exposed to early trauma from developing psychotic symptoms
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