bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitative developmental response to the length of exposure to long photoperiod in wheat and barley
Authors: MIRALLES D. J. , SLAFER G. A. , RICHARDS R. A. , RAWSON H. M. 
Published: January 2004

The present study was designed to analyse the effect of the length of exposure to a long photoperiod imposed c. 3 weeks after sowing in spring wheat (cv. UQ189) and barley (cv. Arapiles) to (i) establish whether the response to the number of cycles of exposure is quantitative or qualitative, (ii) determine the existence of a commitment to particular stages well before the stage has been observable, and (iii) study the interrelationships between the effects on final leaf number and phyllochron when the stimulus is provided several days after seedling emergence. Both wheat and barley seemed to respond quantitatively to the number of long-day cycles they were exposed to. However, wheat showed a requirement of approximately 4 long-day cycles to be able to produce a significant response in time to heading. The barley cultivar used in the study was responsive to the minimum length of exposure. The response to extended photoperiod cycles during the stem elongation phase was due to the ‘memory’ photoperiod effects being related, in the case of wheat, to the fact that the pre-terminal spikelet appearance phase saturated its photoperiod response well before that stage was reached. Therefore, the commitment to the terminal spikelet appearance in wheat may be reached well before this stage could be recognized.As the response in duration to heading exceeded that of the final leaf number, and the stem elongation phase responded to memory effects of photoperiod, the phyllochron of both cereals was responsive to the treatments accelerating the average phyllochron when exposed to longer periods of long days. The response in average phyllochron was due to a switch from bi-linear to linear models of leaf number v. time when the conditions were increasingly inductive, with the phyllochron of the initial (6–8) leaves being similar for all treatments (within each species), and from then on increased.
Depressive disorder as a long-term antecedent risk factor for incident back pain: a 13-year follow-up study from the Baltimore Epidemiological Catchment Area Sample
Authors: LARSON S. L. , CLARK M. R. , EATON W. W. 
Published: January 2004

Background. The co-occurrence of affective distress and back pain is well documented but the relationship between them is less certain. This study examines the relationship between lifetime occurrence of depressive disorder and incident back pain reported over a 13-year period.Method. The Baltimore Epidemiologic Catchment Area Study is a prospective study of a household-residing cohort, selected probabilistically from East Baltimore in 1981. Between 1982–3 (wave 2) and again between 1993–6 (wave 3), a follow-up study of the original cohort was conducted. Questions on depressive disorder and back pain were drawn from the Diagnostic Interview Schedule. Logistic regression analyses were used to evaluate whether depressive disorder acts as a risk factor for incident back pain.Results. In cross-sectional analyses, lifetime occurrence of depressive disorder was a significant correlate of lifetime prevalence of back pain at wave 1 (OR=1·6, P=0·01). During the 13-year follow-up, across three data collection points, there was an increase in the risk for incident back pain when depressive disorder was present at baseline (OR=1·9, 95% CI 1·03, 3·4). However, during the short-term follow-up period of 1 year, between baseline and wave 2, depressive disorder at baseline was unrelated to first-ever reports of back pain. Lifetime depressive disorder in both waves 1 (baseline) and 2 (1 year later) was associated with a more than three times greater risk for a first-ever report of back pain during the 12 to 13 year follow-up period, in comparison to those who did not have depressive disorder at waves 1 or 2 (OR=3·4, 95% CI 1·4, 7·8). Back pain at wave 1 was not significantly associated with an increased risk for depression in the longitudinal analysis (OR=0·8, 95% CI 0·5, 1·4).Conclusions. Depressive disorder appears to be a risk factor for incident back pain independent of other characteristics often associated with back pain. Back pain is not a short-term consequence of depressive disorder but emerges over periods longer than 1 year. Moreover, in this study the alternative pathway of back pain as a risk factor for depressive disorder could not be supported.
Life dissatisfaction and subsequent work disability in an 11-year follow-up
Authors: KOIVUMAA-HONKANEN H. , KOSKENVUO M. , HONKANEN R. J. , VIINAMÄKI H. , HEIKKILÄ K. , KAPRIO J. 
Published: January 2004

Background. Mental disorders are associated with disability, but the long-term effects of low subjective well-being on work ability in general population are not known. In this study we investigated whether self-reported life dissatisfaction predicts work disability.Method. A nationwide sample of Finnish twins aged 18–54 years (N=22 136), unselected for health status responded to a health questionnaire with a four-item life satisfaction scale (range 4–20) covering interest, happiness, easiness and loneliness of life in 1975 and 1981. Cox regression for all subjects and conditional logistic regression for discordant twin pairs were used to compare the risk of subsequent work disability (N=1200) (Nationwide Disability Register) between the dissatisfied and satisfied.Results. Life dissatisfaction predicted subsequent (1977–87) work disability pension due to psychiatric and non-psychiatric causes among the healthy at baseline, and that due to psychiatric causes among the ill. After controlling for age, marital status, social class and health behaviour, these risks remained significant. Repeatedly reported (1975 and 1981) life dissatisfaction was strongly associated with increased (age-adjusted) risk of subsequent (1982–87) work disability due to psychiatric and also that due to non-psychiatric causes among the healthy. When twin pairs discordant for end-point disability status were analysed, risk differences related to life satisfaction were only slightly decreased, but they did not differ significantly between monozygotic and dizygotic pairs.Conclusion. Life dissatisfaction predicts subsequent work disability especially among the healthy.
Intergenerational transmission of somatization behaviour: 2. Observations of joint attention and bids for attention
Authors: CRAIG T. K. J. , BIALAS I. , HODSON S. , COX A. D. 
Published: January 2004

Background. Somatoform disorders may have their roots in childhood through processes that involve an enhanced parental focus on health. The aim of this study was to test the hypothesis that somatizing mothers will show less joint involvement than other mothers during play but greater responsiveness when this play involves a ‘medical’ theme.Method. Cross-sectional observational study of 42 chronic somatizers, 44 organically ill and 50 healthy mothers and their 4–8 year-old children during structured play and a meal. Tasks comprised boxes containing tea-set items, ‘medical’ items and a light snack.Results. Somatizing mothers were emotionally flatter and showed lower rates of joint attention than other mothers during both play tasks. While the three groups had similar rate of bids for attention, somatizing mothers were more responsive to their child's bids during play with the medical box than at other times. In contrast, the children of somatizing mothers ignored a greater proportion of their mother's bids during play with the medical box than did children of other mothers or during play with a non-medical theme.Conclusion. The study has demonstrated tentative evidence in support of the hypothesis.
Duration of untreated psychosis: impact on 2-year outcome
Authors: ADDINGTON J. , VAN MASTRIGT S. , ADDINGTON D. 
Published: January 2004

Background. The duration of untreated psychosis has been postulated to be a predictor of clinical outcome in schizophrenia. Although several prospective studies support the relationship, some studies do not. These differences may be due to a number of methodological issues. The objectives of this study are: (i) to address many of the methodological limitations of earlier studies such as variations in sample size and selection, type of treatment provided, differences in measurement of DUP and outcome, and length of follow-up; and (ii) to examine the relationship between DUP and outcome in a prospective longitudinal study.Method. The DUP of 200 consecutive admissions to a first-episode programme was determined. The sample was followed over 2 years and pre-morbid functioning, symptoms, social and cognitive functioning and substance use were assessed longitudinally.Results. Two years after admission to the programme, longer DUP was significantly associated with high levels of positive symptoms and poor social functioning. Independently of other variables, DUP predicted positive symptoms and social functioning at 1 and 2 years.Conclusions. There is evidence that long DUP continues to have an influence on outcome up to 2 years. These results support ongoing efforts for early detection and intervention.
Patients with schizophreniform disorder use verbal descriptions for the representation of visual categories
Authors: KÉRI S. , KELEMEN O. , BENEDEK G. , JANKA Z. 
Published: January 2004

Background. Neuropsychological impairment is a common finding in schizophrenia. However, a significant proportion of patients are not impaired in conventional neuropsychological tests. In this study, we investigated whether remitted patients with schizophreniform disorder exhibited dysfunctions in specific cognitive tasks.Method. Twenty remitted, highly functioning patients with schizophreniform disorder and 20 control subjects participated in the study. In addition to background neuropsychological evaluation (WAIS-R IQ, Wisconsin Card Sorting Test (WCST), Trail Making B, Rey–Osterrieth Complex Figure), subjects received a category learning task. The categories consisted of geometric shapes systematically changing in shape and size. Training included the sequential presentation of category members (visual learning) and verbal description of categories.Results. The patients with schizophreniform disorder had normal IQ, executive functions/psychomotor speed (WCST and Trail Making B) and visual memory (Rey–Osterrieth Complex Figure). In contrast, they displayed impaired categorization performances after visual learning. The performance of the patients improved markedly after verbal description of categories. Verbal knowledge about categories positively correlated with categorization performance in the patients, but not in the controls.Conclusions. Category learning functions, which include decision-making under uncertainty and feature integration, are impaired in patients with schizophreniform disorder who display normal executive functions and visual memory. These patients may use verbal knowledge as a compensatory strategy in visual tasks.
The evolution of insight, paranoia and depression during early schizophrenia
Authors: DRAKE R. J. , PICKLES A. , BENTALL R. P. , KINDERMAN P. , HADDOCK G. , TARRIER N. , LEWIS S. W. 
Published: January 2004

Background. How insight, paranoia and depression evolve in relation to each other during and after the first episode of schizophrenia is poorly understood but of clinical importance.Method. Serial assessments over 18 months were made using multiple instruments in a consecutive sample of 257 patients with first episode DSM-IV non-affective psychosis. Repeated measures of paranoia, insight, depression and self-esteem were analysed using structural equation modelling, to examine the direction of relationships over time after controlling for confounds.Results. Depression was predicted directly by greater insight, particularly at baseline, and by greater paranoia at every stage of follow-up. Neither relationship was mediated by self-esteem, although there was a weak association of lower self-esteem with greater depression and better insight. Paranoia was not strongly associated with insight. Duration of untreated psychosis and substance use at baseline predicted depression at 18 months.Conclusions. In first-episode psychosis, good insight predicts depression. Subsequently, paranoia is the strongest predictor. Neither effect is mediated by low self-esteem. Effective treatment of positive symptoms is important in preventing and treating low mood in early schizophrenia.
The prediction of thoughts of death or self-harm in a population-based sample of female twins
Authors: FANOUS A. H. , PRESCOTT C. A. , KENDLER K. S. 
Published: January 2004

Background. Although suicide is a leading cause of death, few studies have attempted to predict suicidal ideation prospectively using epidemiological samples or multivariate methods.Method. Discrete-time event history analysis was used to model the onset of thoughts of death or self-harm (TD/SH) in a population-based sample of female twins (N=2164) using variables from the demographic, psychopathological, childhood adversity, personality and life event domains. Univariate, multivariate-within domain and multivariate-across domain regression analyses were performed.Results. Most variables predicted TD/SH in the univariate analyses. However, the only variables to predict TD/SH independently were obsessive symptoms, childhood sexual abuse, rural residence, unemployment, older age, lifetime history of cocaine misuse and low levels of education, personal religious devotion and altruism, as well as divorce/separation, loss of confidant, assault, job loss and financial problems in the previous month. This final model explained 16% of the variance in TD/SH. Lifetime histories of major depression, panic disorder and alcohol misuse had no significant independent effect.Conclusions. Many variables, from all five domains of risk factors, are associated with the risk of TD/SH, but many of these effects may be mediated by other risk factors. Proximal life events and psychopathology may have more independent effects than other domains. The overall ability of these risk factors to predict TD/SH is modest. We cannot rule out that differences between these analyses and previous reports were due to our use of TD/SH as the dependent variable instead of thoughts of committing suicide per se.
Daily smoking and the subsequent onset of psychiatric disorders
Authors: BRESLAU N. , NOVAK S. P. , KESSLER R. C. 
Published: January 2004

Background. Recent research has demonstrated that smokers are at an elevated risk for psychiatric disorders. This study extends the enquiry by examining: (1) the specificity of the psychiatric sequelae of smoking; and (2) the variability in the likelihood of these sequelae by proximity and intensity of smoking.Method. Data come from the National Comorbidity Survey (NCS), a representative sample of the US population 15–54 years of age. The Smoking Supplement was administered to a representative subset of 4414 respondents. A modified World Health Organization – Composite International Diagnostic Interview was used to measure DSM-III-R disorders. Survival analysis with smoking variables as time-dependent covariates was used to predict the subsequent onset of specific psychiatric disorders.Results. The estimated effects of daily smoking varied across disorders. In the case of mood disorders, daily smoking predicted subsequent onset, with no variation between current versus past smokers or by smoking intensity. In the case of panic disorder and agoraphobia, current but not past smoking predicted subsequent onset; furthermore, the risk of these disorders in past smokers decreased with increasing time since quitting. In the case of substance use disorders, current but not past smoking predicted subsequent onset, with no variation by time since quitting or smoking intensity.Conclusions. The data suggest that smoking cessation programmes would not prevent the onset of mood disorder, as ex-smokers do not differ from current smokers in their risk for these disorders. In comparison, daily smoking might be a causal factor in panic disorder and agoraphobia, conditions that might be preventable by smoking cessation. Additionally, current smoking might serve as a marker for targeting interventions to prevent alcohol and drug disorders.
Health care contacts before and after attempted suicide among adolescent and young adult versus older suicide attempters
Authors: SUOMINEN K. , ISOMETSÄ E. , MARTUNNEN M. , OSTAMO A. , LÖNNQVIST J. 
Published: January 2004

Background. The pattern of all health care contacts among young people before and after attempted suicide is not well documented. Neither is it known if the health care contacts of young suicide attempters differ from those of older suicide attempters. This study investigated the age-related clinical characteristics of suicide attempters and the pattern of their contacts with health care before and after attempted suicide in different age groups, particularly adolescence and young adulthood.Method. All consecutive 1198 suicide attempters treated in hospital emergency rooms in Helsinki between January 1997 and January 1998 were identified and divided into three age groups (15–24 years, 25–39 years, 40 years and over). Data were gathered on all health care contacts 1 year before and after the index attempt.Results. Although adolescent and young adult suicide attempters suffered from severe mental disorders, a remarkable proportion of them were left without psychiatric consultation and aftercare recommendation following the attempt. Two-thirds of 15–19-year-old male suicide attempters had no treatment contact during the month before the attempt, while a quarter of them were referred to psychiatric consultation and a half had no healthcare contact in the month following the attempt.Conclusions. These findings indicate considerable scope for improvement in the assessment of young suicide attempters and their referral to aftercare.
Medications and verbal memory impairment in schizophrenia: the role of anticholinergic drugs
Authors: BRÉBION G. , BRESSAN R. A. , AMADOR X. , MALASPINA D. , GORMAN J. M. 
Published: January 2004

Background. We wished to assess the effect of three types of medication on verbal memory impairments in schizophrenia.Method. Forty-eight patients with schizophrenia and 40 healthy control subjects underwent a battery of verbal memory tasks, including free recall, recognition and short-term memory span. All the patients were on antipsychotic medication. In addition, 24 were taking anticholinergic drugs (benztropine) and 30 were taking benzodiazepines. A subsample of 39 had clinical ratings for depressive symptoms. Regression analyses were conducted on the memory measures in this subsample, with negative symptoms, depression, type of antipsychotic medication (conventional v. atypical), benzodiazepines and anticholinergic drugs as predictors.Results. Type of antipsychotic medication made no significant contribution to memory deficits and benzodiazepine use made very little contribution. However, anticholinergic medication was a predictor of memory impairment, especially with regard to semantic organization. Complementary analyses revealed that patients taking any type of drug with anticholinergic activity (benztropine and/or antipsychotic agents) were significantly impaired relative to the other patients on measures reflecting free recall efficiency and semantic organization.Conclusions. Drugs with anticholinergic activity are the major pharmacological agents that contribute to the verbal memory deficit observed in patients with schizophrenia. These drugs appear to act by impeding semantic organization at encoding.
Actions taken to cope with depression at different levels of severity: a community survey
Authors: JORM A. F. , GRIFFITHS K. M. , CHRISTENSEN H. , PARSLOW R. A. , ROGERS B. 
Published: January 2004

Background. Many people with symptoms of psychological distress do not seek professional help. Little is known about the actions taken by these people to reduce their symptoms. The present study aimed to assess, in a community sample, actions taken to cope with depression at different levels of psychological distress.Method. A postal survey was carried out with 6618 adults living in Canberra and south-east New South Wales, Australia. Measures covered psychological distress and a checklist of actions taken to cope with depression in the previous 6 months.Results. Actions taken to cope with depression could be classified as: intensification of everyday strategies, initiation of new self-help (including complementary therapies, non-prescription medication and dietary changes) and seeking professional help. Use of everyday strategies peaked with mild psychological distress, new self-help showed a peak in moderate distress, while professional help-seeking peaked in severe distress.Conclusion. Self-help strategies are very commonly used, particularly in mild–moderate psychological distress. More evidence is needed to evaluate their effectiveness, so that optimal self-help can be encouraged.
Simulating the ice‐thickness distribution in a coupled climate model
Authors: Bitz C. M. , Holland M. M. , Weaver A. J. , Eby M. 
Published: February 2004

Climate simulations in a global coupled model are investigated using a dynamic‐thermodynamic sea ice and snow model with sophisticated thermodynamics and a subgrid scale parameterization for multiple ice thicknesses. In addition to the sea ice component, the model includes a full primitive‐equation ocean and a simple energy‐moisture balance atmosphere. We introduce a formulation of the ice thickness distribution that is Lagrangian in thickness‐space. The method is designed to use fewer thickness categories because it adjusts to place resolution where it is needed most and it is free of diffusive effects that tend to smooth Eulerian distributions. Experiments demonstrate that the model does reasonably well in simulating the mean Arctic climate. We find the climate of the Arctic and northern North Atlantic is sensitive to resolving the ice‐thickness distribution when comparing the model results to a simulation with a two‐level sea ice model. The ice‐thickness distribution causes ice export through Fram Strait to be more variable and more strongly linked to meridional overturning in the North Atlantic Ocean.The Lagrangian formulation of the ice‐thickness distribution allows for the inclusion of a vertical temperature profile with relative ease compared to an Eulerian method. We find ice growth rates and ocean surface salinity differ in our model with a well‐resolved vertical temperature profile in the ice and snow and an explicit brine‐pocket parameterization compared to a simulation with Semtner zero‐layer thermodynamics. Although these differences are important for the climate of the Arctic, the effects of an ice thickness distribution are more dramatic and extend into the northern North Atlantic. Sensitivity experiments indicate that five ice‐thickness categories with ∼50‐cm vertical temperature resolution capture the effects of the ice‐thickness distribution on the heat and freshwater exchange across the surface in the presence of sea ice in these simulations.