Search for anomalous heavy-flavor quark production in association with W bosons

We search for anomalous production of heavy-flavor quark jets in association with W bosons at the Fermilab Tevatron pp Collider in final states in which the heavy-flavor quark content is enhanced by requiring at least one tagged jet in an event. Jets are tagged using one algorithm based on semileptonic decays of b/c hadrons, and another on their lifetimes. We compare e+jets (164 pb(-1)) and mu+jets (145 pb(-1)) channels collected with the D0 detector at sqrt[s]=1.96 TeV to expectations from the standard model and set upper limits on anomalous production of such events.

Measurement of the WW production cross section in pp collisions at square root[s]=1.96 TeV

We present a measurement of the W boson pair-production cross section in pp collisions at a center-of-mass energy of sqrt[s]=1.96 TeV. The data, collected with the Run II D0 detector at Fermilab, correspond to an integrated luminosity of 224-252 pb(-1) depending on the final state (ee, emu, or mumu). We observe 25 candidates with a background expectation of 8.1+/-0.6(stat)+/-0.6(syst)+/-0.5(lum) events. The probability for an upward fluctuation of the background to produce the observed signal is 2.3x10(-7), equivalent to 5.2 standard deviations. The measurement yields a cross section of 13.8(+4.3)(-3.8)(stat)+1.2-0.9(syst)+/-0.9(lum) pb, in agreement with predictions from the standard model.

Measurement of the Lambda0b lifetime in the decay lambda0b--> J/psiLambda0 with the D0 detector

We present measurements of the Lambda(0)(b) lifetime in the exclusive decay channel Lambda(0)(b)--> J/psiLambda(0), with J/psi--> mu(+)mu(-) and Lambda(0)--> ppi(-), the B0 lifetime in the decay B0-->J/psiK(0)(S) with J/psi--> mu(+)mu(-) and K(0)(S)-->pi(+)pi(-), and the ratio of these lifetimes. The analysis is based on approximately 250 pb(-1) of data recorded with the D0 detector in pp collisions at sqrt[s] = 1.96 TeV. The Lambda(0)(b) lifetime is determined to be tau(Lambda(0)(b)) = 1.22(+0.22)(-0.18)(stat) +/- 0.04(syst) ps, the B0 lifetime tau(B0) = 1.40(+0.11)(-0.10)(stat) +/- 0.03(syst) ps, and the ratio tau(Lambda(0)(b))/tau(B0) = 0.87(+0.17)(-0.14)(stat) +/- 0.03(syst). In contrast with previous measurements using semileptonic decays, this is the first determination of the Lambda(0)(b) lifetime based on a fully reconstructed decay channel.

Search for Wbb and WH production in pp collisions at square root [s]=1.96 TeV

We present a search for Wbb production in pp collisions at sqrt[s]=1.96 TeV in events containing one electron, an imbalance in transverse momentum, and two b-tagged jets. Using 174 pb(-1) of integrated luminosity accumulated by the D0 experiment at the Fermilab Tevatron collider, and the standard-model description of such events, we set a 95% C.L. upper limit on Wbb production of 6.6 pb for b quarks with transverse momenta p(b)(T)>20 GeV and bb separation in pseudorapidity-azimuth space DeltaR(bb)>0.75. Restricting the search to optimized bb mass intervals provides upper limits on WH production of 9.0-12.2 pb for Higgs-boson masses of 105-135 GeV.

Search for the flavor-changing neutral current decay B0s--> mu(+) mu(-) in pp Collisions at sqrt[s] = 1.96 TeV with the D0 detector

We present the results of a search for the flavor-changing neutral current decay B(0)(s)--> mu(+) mu(-) using a data set with integrated luminosity of 240 pb(-1) of pp collisions at sqrt[s] = 1.96 TeV collected with the D0 detector in run II of the Fermilab Tevatron collider. We find the upper limit on the branching fraction to be B(B(0)(s)--> mu(+) mu(-)) < or= 5.0 x 10(-7) at the 95% C.L. assuming no contributions from the decay B(0)(d)--> mu(+) mu(-) in the signal region. This limit is the most stringent upper bound on the branching fraction B(0)(s)--> mu(+) mu(-) to date.

Search for supersymmetry with gauge-mediated breaking in diphoton events at D0

We report the results of a search for supersymmetry (SUSY) with gauge-mediated breaking in the missing transverse energy distribution of inclusive diphoton events using 263 pb(-1) of data collected by the D0 experiment at the Fermilab Tevatron Collider in 2002-2004. No excess is observed above the background expected from standard model processes, and lower limits on the masses of the lightest neutralino and chargino of about 108 and 195 GeV, respectively, are set at the 95% confidence level. These are the most stringent limits to date for models with gauge-mediated SUSY breaking with a short-lived neutralino as the next-to-lightest SUSY particle.

Measurement of the B0s lifetime in the exclusive decay channel B0s-->J/psiphi

Using the exclusive decay B0s-->J/psi(mu+mu-)phi(K+K-), we report the most precise single measurement of the B0s lifetime. The data sample corresponds to an integrated luminosity of approximately 220 pb(-1) collected with the D0 detector at the Fermilab Tevatron Collider in 2002-2004. We reconstruct 337 signal candidates, from which we extract the B0s lifetime, tau(B0s)=1.444(+0.098)(-0.090)(stat)+/-0.020(sys) ps. We also report a measurement for the lifetime of the B0 meson using the exclusive decay B0-->J/psi(mu+mu-)K*0(892)(K+pi-). We reconstruct 1370 signal candidates, obtaining tau(B0)=1.473(+0.052)(-0.050)(stat)+/-0.023(sys) ps, and the ratio of lifetimes, tau(B0s)/tau(B0)=0.980(+0.076)(-0.071)(stat)+/-0.003(sys).

Analysis of spatial patterns at a geographical scale over north-western Europe from point-referenced aphid count data

The spatial analysis by distance indices (SADIE) technique was developed to evaluate the spatial pattern of point-referenced count data as well as the spatial association between two sets of data sharing the same point locations. This paper presents an analysis of spatial patterns in aphid count data and the association of these data with climate across north-west Europe. The paper tests the applicability of the technique to large geographical areas. Aggregation and cluster indices were calculated for the total annual abundance of the peach-potato aphid Myzus persicae (Sulzer) and for the annual mean rainfall and temperature at aphid monitoring sites. Association indices demonstrated the stability in time of aphid spatial structures and the correlation between aphid density and climate patterns. Groups of relatively large numbers of aphids, termed patches, and groups of relatively small numbers of aphids, termed gaps, were located and their mean size estimated. The aphid patterns were quite stable in time and the spatial patterns of temperature and rainfall were weakly associated with M. persicae annual abundance. Similarities were observed between the results of SADIE and those from the more widely used technique of spatial autocorrelation (SAC). However, the SADIE association index has the advantage of quantifying the possible associations between aphid data and the factors that determine population distribution. Thus, high temperature and low rainfall were identified as environmental factors that were positively associated with aphid abundance across north-west Europe.

Evidence for gene flow and local clonal selection in field populations of the grain aphid (Sitobion avenae) in Britain revealed using microsatellites

Samples of the grain aphid, Sitobion avenae (F.), a major European pest of cereals, were collected in June and July 1997 from fields sown with winter wheat in a rough transect south-west of Rothamsted, UK. These aphids were genotyped at four microsatellite loci known from previous studies to be highly polymorphic. Allelic frequencies were similar between samples collected in the fields and in the 12.2 m high suction trap at Rothamsted, and there were many widespread genotypes (clones), providing evidence that the species is highly migratory. However, field samples were found to display a high level of genotypic heterogeneity (= variable clonal composition), most probably the result of clonal selection. The suction trap genotypes sample were slightly different from the field samples, indicative of the inclusion of genotypes from plant hosts (cereals and grasses, Poaceae) other than winter wheat and/or genotype-biased emigration from the field. The relevance of these data to modelling of aphid outbreaks is briefly discussed.

Mothers' mental health and infant growth: a case-control study from Rawalpindi, Pakistan

BACKGROUND

Epidemiological studies in Pakistan show high rates of depression in women, while rates of malnutrition in children are also high. This study aimed to determine whether poor maternal mental health is associated with an increased risk of infant undernutrition.

METHODS

Clinic-based case-control study. A total of 172 consecutive infants and their mothers attending for 9-month measles immunization were recruited over a 3-month period. Eighty-two undernourished infants [weight for age below the National Centre for Health Statistics (NCHS)/World Health Organization (WHO) third centile] were matched to 90 controls (weight for age above 10th centile), and their mothers interviewed for mental distress using the Self-Reporting Questionnaire (WHO SRQ-20, a psychiatric screening instrument). Infants' exposure to maternal distress (score > or = 10 on SRQ-20) and other potential risk or protective biological, social, socio-economic and family factors were measured.

RESULTS

Mental distress determined by WHO SRQ-20 was associated with increased risk of undernutrition in infants (odds ratio 3.91, 95% confidence interval 1.95-7.86). This association remained significant after controlling for birthweight and social factors.

CONCLUSION

Exposure to maternal mental distress is associated with undernutrition in 9-month infants in urban Pakistan. These mothers may represent a group whose children are at higher risk of ill health, and potentially be a specific target for advice on infant care. Early recognition and treatment of mental health problems in mothers may help reduce morbidity and mortality rates in children.

Life events, social support and depression in childbirth: perspectives from a rural community in the developing world

BACKGROUND

High rates of depression associated with childbirth have been reported in many parts of the developing world. However, the prevalence and associations of antenatal and post-natal depression in the rural population remain unknown. Disability associated with depression and its impact on infant health and development could have important public health implications for many developing countries where large proportions of the population are rural.

METHOD

All women living in southern Kahuta, Pakistan, in their third trimester of pregnancy were interviewed at 6 weeks before delivery (N = 632) and again at 10-12 weeks after delivery (N = 541), using WHO Schedule for Clinical Assessment in Neuropsychiatry (SCAN), Personal Information Questionnaire (PIQ) and Brief Disability Questionnaire (BDQ).

RESULTS

The point prevalence of ICD-10 depressive disorder was 25% in the antenatal period and 28 % in the post-natal period. Depressed mothers were significantly more disabled, had more threatening life events, and poorer social and family support than non-depressed mothers. Vulnerable mothers were more likely to be depressed during pregnancy, rather than have an onset in the post-natal period.

CONCLUSION

Over one-quarter of mothers in a rural sub-district of Pakistan suffer from depression shortly before and after childbirth. Rapidly changing traditional family structures and practices may be increasing the risk of depression in many women. Recognizing and treating depression should be initiated during the antenatal, rather than post-natal period.

Migration and genetic structure of the grain aphid (Sitobion avenae) in Britain related to climate and clonal fluctuation as revealed using microsatellites

Genetic structuring of populations reflects the interaction of genetic drift, mutation, migration and selection, with influences from life history. Aphids are interesting in this regard as they have the potential for unusually high levels of dispersal and natural selection, which typically counter each other. In the present study, winged grain aphids Sitobion avenae (F.) were collected in four 12.2-m high suction traps along a north-south transect in Britain in order to eliminate sampling bias from plant hosts (cereals and grasses; Poaceae), it being known that these insects show host adaptation demonstrable using molecular markers. Samples were analysed at four polymorphic microsatellite loci over two consecutive years. Population allele frequencies were similar nationally during the two years, although clonal diversity varied greatly between sites and years. In the first sampling year following a harsh winter, diversity was found to display a latitudinal clinal trend: the proportion of unique clones (genotypes) increased with latitude. However, this pattern was less apparent the following year, after a milder winter. Nonetheless, overall FST analysis showed that there was little spatial genetic structuring in either sampling year. These data support the view that the insect is highly migratory and also support a theoretical model and previous data suggesting that the reproductive mode is clinal in S. avenae. This appears to be because natural selection (reduced reproductive success of asexual genotypes under cold conditions) is sufficiently powerful to overcome the homogenizing effects of strong migration. There was no clear evidence for isolation by distance for the genetic data obtained. The data are compared with similar data from other aphid species and other insects. Only by the collection of such data sets can an accurate picture be built up relating genetic variability to flight behaviour, including migratory ambit in this group of insects since, due to their small size and rapid dilution in the air, other marking approaches are impracticable over large geographical distances.

Can maternal depression increase infant risk of illness and growth impairment in developing countries?

Despite relative improvement in living conditions and availability of modern healthcare, infant mortality rates continue to be very high in many developing countries. High rates of depression have also been reported in women in these countries. The continuous care and attention of children is a demanding task, and poor physical or mental health in mothers might be expected to have adverse consequences on their children's health, nutrition and psychological well-being. Review of published literature reveals very little research in developing countries on the association between poor mental health in mothers and the subsequent physical well-being of their children. We hypothesize that the level of care provided by mothers with depression may put their infants at higher risk of infection and impaired growth, compared with infants of mothers without depression. We outline approaches to test such a hypothesis in a developing country, and discuss its implications.

Susceptibility genes for a trait measure of attention deficit hyperactivity disorder: a pilot study in a non-clinical sample of twins

Attention deficit hyperactivity disorder (ADHD) is a highly heritable disorder, and molecular genetic studies are underway, with most researchers focusing on identifying susceptibility genes in clinical samples with ADHD. An alternative approach is to search for quantitative trait loci underlying the trait measure of ADHD in non-clinical samples. Positive findings of association of the dopamine transporter DAT1 480 bp allele (allele 10) and the DRD4 7 repeat allele with clinical ADHD have been previously reported. In this pilot study, we examined these polymorphisms in a selected population-based sample of twins (50 high scoring pairs, 42 low scoring pairs). There was a trend for an increase in the frequency of the dopamine receptor DRD4 7 repeat allele in the high-scoring concordant monozygotic twins (odds ratio=1.4). Although this result was not statistically significant, the frequency of the 7 repeat allele was similar to that reported for our clinic sample of ADHD patients drawn from the same geographical area. There was a non-significant trend for an increased frequency of the DAT1 allele 10 (odds ratio=1.3). These results suggest that a molecular genetic study based on a questionnaire-derived measure of ADHD in a non-clinical sample is feasible and the results appear to be comparable with those from studies of clinical cases. However, sample size and power are key issues to consider when using this approach.

Randomized trial of group therapy for repeated deliberate self-harm in adolescents

OBJECTIVE

To compare group therapy with routine care in adolescents who had deliberately harmed themselves on at least two occasions within a year.

METHOD

Single-blind pilot study with two randomized parallel groups that took place in Manchester, England. Sixty-three adolescents aged 12 through 16 years were randomly assigned to group therapy and routine care or routine care alone. Outcome data on suicide attempts were obtained without knowledge of treatment allocation on all randomized cases (62/63 by direct interview) on average 29 weeks later. The primary outcomes were depression and suicidal behavior.

RESULTS

In intention-to-treat analyses, adolescents who had group therapy were less likely to be "repeaters" at the end of the study (i.e., to have repeated deliberate self-harm on two or more further occasions) than adolescents who had routine care (2/32 versus 10/31; odds ratio 6.3), but the confidence intervals for this ratio were wide (95% confidence interval 1.4 to 28.7). They were also less likely to use routine care, had better school attendance, and had a lower rate of behavioral disorder than adolescents given routine care alone. The interventions did not differ, however, in their effects on depression or global outcome.

CONCLUSIONS

Group therapy shows promise as a treatment for adolescents who repeatedly harm themselves, but larger studies are required to assess more accurately the efficacy of this intervention.

The Maudsley long-term follow-up of child and adolescent depression. 2. Suicidality, criminality and social dysfunction in adulthood

BACKGROUND

Strong links exist between juvenile and adult depression, but comorbid conduct disorder may be associated with worse adult social difficulties.

AIMS

To test the impact of comorbid conduct disorder on social adjustment and dysfunction, suicidality and criminality of adults who had had depression as youths.

METHOD

Subjects (n=149) assessed at the Maudsley Hospital in 1970-1983 and meeting DSM-IV criteria for major depressive disorder with (CD-MDD; n=53) or without (MDD; n=96) conduct disorder were interviewed 20 years later. Data were collected on lifetime psychiatric disorders and adult social/personality functioning. Death certificates and criminal records were obtained.

RESULTS

The suicide risk was 2.45%, and 44.3% of the sample had attempted suicide once in their lives. Compared with the MDD group, the CD-MDD group had higher rates of suicidal behaviours and criminal offences, and exhibited more pervasive social dysfunction.

CONCLUSIONS

Adolescent depression is associated with raised risks of adult suicidality and with persistent interpersonal difficulties. Youths with CD-MDD show more severe and pervasive social dysfunction.

The Maudsley long-term follow-up of child and adolescent depression. 1. Psychiatric outcomes in adulthood

BACKGROUND

Strong links exist between juvenile and adult depression but comorbid conduct disorder in childhood may mitigate this continuity.

AIMS

To test the impact of comorbid conduct disorder on psychiatric adult outcomes.

METHOD

A group of 149 subjects assessed at the Maudsley Hospital in the period 1970-1983 and meeting DSM-IV criteria for major depressive disorder with (n=53) or without (n=96) conduct disorder were interviewed 20 years later. Data were collected on the lifetime history of psychiatric disorders.

RESULTS

Adult depressive recurrence was high for major depression (62.4%) and any depression (75.2%), and survival analyses showed no difference between the two groups. The group with conduct disorders had higher rates of drug misuse and dependence, alcoholism and antisocial personality disorders.

CONCLUSIONS

Adolescent depression carries an elevated risk of adult depression irrespective of comorbidity. Comorbid conduct disorder in childhood is associated with raised rates of other psychiatric outcomes.

Examining the comorbidity of ADHD-related behaviours and conduct problems using a twin study design

BACKGROUND

Although attention-deficit hyperactivity disorder (ADHD) and conduct disorder (CD) frequently co-occur, the underlying mechanisms for this comorbidity are not well understood.

AIMS

To examine whether ADHD and conduct problems share common risk factors and whether ADHD+CD is a more heritable variant of ADHD.

METHOD

Questionnaires were sent to 2846 families. Parent-rated data were obtained for 2082 twin pairs and analysed using bivariate genetic analysis and a liability threshold model approach.

RESULTS

The overlap of ADHD and conduct problems was explained by common genetic and non-shared environmental factors influencing both categories. Nevertheless, the two categories appeared to be partly distinct in that additional environmental factors influenced conduct problems. It appeared that ADHD+CD was a genetically more severe variant of ADHD.

CONCLUSIONS

Conduct problems and ADHD share a common genetic aetiology; ADHD+CD appears to be a more severe subtype in terms of genetic loading as well as clinical severity.

The treatment of child and adolescent mental health problems in primary care: a systematic review

BACKGROUND

There is significant potential to increase the accessibility and effectiveness of child and adolescent mental health services through the involvement of primary care professionals and the delivery of interventions in the primary care setting. However, little is known about the actual clinical and cost-effectiveness of such service delivery.

OBJECTIVE

The aim of the study was to review systematically the evidence concerning the effectiveness of interventions for child and adolescent mental health problems in primary care, and interventions designed to improve the skills of primary care staff.

METHODS

Searches were made of The Cochrane Clinical Trials Register, MEDLINE, PSYCINFO, EMBASE and CINAHL, together with correspondence with subject experts and authors of studies, and checking of references in identified papers.

RESULTS AND CONCLUSIONS

There was some preliminary evidence that treatments by specialist staff working in primary care were effective, although the quality of included studies was variable and no data were available on the cost-effectiveness of interventions. Equally, some educational interventions show potential for increasing the skills and confidence of primary care staff, but controlled evaluations were rare and few studies reported actual changes in professional behaviour or patient health outcomes. A significant programme of research is required if the potential for child and adolescent mental health services in primary care is to be realized in an effective and efficient way.

The effect of natural enemies on the spread of barley yellow dwarf virus (BYDV) by Rhopalosiphum padi (Hemiptera: Aphididae)

The effects of two natural aphid enemies, adult Coccinella septempunctata Linneaus, a predator, and Aphidius rhopalosiphi de Stefani Perez, a parasitoid, on spread of barley yellow dwarf virus (BYDV) transmitted by the bird cherry-oat aphid, Rhopalosiphum padi (Linnaeus) were studied under laboratory conditions. Predators or parasitoids were introduced to trays of durum wheat seedlings and the patterns of virus infection were observed after two, seven and 14 days of exposure. More plants were infected with BYDV in control trays without A. rhopalosiphi than in trays with the parasitoid present, both seven and 14 days after the introduction of parasitoids. Patterns of virus infection were found to be similar over time in trays with a parasitoid present and in control trays. More plants were infected in trays with C. septempunctata present than in control trays, both two and seven days after the introduction of the coccinellid. The spread of virus infections progressed differently over time for the two treatments (predator and parasitoid), differences between treatments being most marked after two days and seven days, when more plants exposed to predators but fewer exposed to parasitoids were infected with BYDV compared to their respective controls. However, by the 14th day 88% of all plants were infected and there was no significant difference between the two treatments. The role of natural enemies in spread of BYDV is discussed.