bluuebunny/crossref_metadata_2025_split huggingface dataset:
Laminar–turbulent transition in Poiseuille pipe flow subjected to periodic perturbation emanating from the wall.
Part 2. Late stage of transition
Authors: HAN G. , TUMIN A. , WYGNANSKI I. 
Published: July 2002

Transition in a fully developed circular pipe flow was investigated experimentally
by introducing periodic perturbations. The simultaneous excitation of helical modes
having indices m = ±1, ±2 and ±3 was chosen. The experiments revealed that the
late stage of transition is accompanied by the formation of streaky structures that
are associated with peaks and valleys in the azimuthal distribution of the streamwise
velocity disturbance. The breakdown to turbulence starts with the appearance of
spikes in the temporal traces of the velocity. Spectral characteristics of these spikes
and the direction of their propagation relative to the wall are similar to those in
boundary layers. Analysis of the data suggests the existence of a high-shear layer in
the instantaneous velocity profile.Additional experiments in which a very weak, steady flow was added locally to the
periodic axisymmetric perturbation were also carried out. These experiments resulted
in the generation of a single peak in the azimuthal distribution of the disturbance
amplitude. The characteristics of the transition process (spikes, vortical patterns etc.)
within this peak were similar to ones observed in the helical excitation experiments.
Based on these results one may conclude that late stages of transition in a pipe
flow and in a boundary layer are similar. The present report is part of an ongoing
investigation that was initiated by Eliahou, Tumin & Wygnanski (1998a).
Transition from dripping to jetting
Authors: CLANET CHRISTOPHE , LASHERAS JUAN C. 
Published: July 2002

We consider the critical Weber number
(Wec≡
ρV20D/σ)
at which the transition from
dripping to jetting occurs when a Newtonian liquid of density ρ and
surface tension
σ is injected with a velocity V0 through a tube

of diameter D downward into stagnant
air, under gravity g. We extend Taylor's (1959) model for

the recession speed of a free
edge, and obtain in the inviscid limit an exact solution which includes
gravity and
inertia effects. This solution provides a criterion for the transition
which is shown to
occur at a critical Weber numberformula herewhere Bo and Boo are the Bond numbers
(Bo≡[ρgD2/(2σ)]1/2),

respectively based on the inside and outside diameter of the tube, and
K is a
constant equal to 0.37 for the case of water injected in air. This critical
Weber
number is shown to be in good agreement with existing experimental values
as well as
with new measurements performed over a wide range of Bond numbers.
Wavelet analyses of velocities in laboratory
isotropic turbulence
Authors: MOURI H. , KUBOTANI H. , FUJITANI T. , NIINO H. , TAKAOKA M. 
Published: July 2002

Orthonormal wavelet transformations are used to decompose velocity signals of grid
turbulence into both space and scale. The transforms exhibit small-scale enhancements
of (i) the spatial fluctuation, (ii) the correlation in space between the adjacent scales,
and (iii) the correlation in space between the longitudinal and transverse components.
The spatial fluctuation and the scale–scale correlation at small scales are more
significant in the transverse component than in the longitudinal component. These
features are the same for different families of wavelets.Turbulence contains tube-like structures of vorticity. We demonstrate that wavelet
transforms of velocities are enhanced at the positions of the tubes, by using a direct
numerical simulation. Thus our wavelet analyses have captured the effects of those
coherent structures on velocities measured in the experiment, which would be difficult
for traditional analysis techniques such as those with velocity increments.
A preliminary population-based twin study of self-reported eating disorder
Authors: KORTEGAARD L. S. , HOERDER K. , JOERGENSEN J. , GILLBERG C. , KYVIK K. O. 
Published: July 2002

Background. Twin studies have concluded that there is a substantial genetic contribution to the
aetiology of eating disorders. The aim of the present study was to estimate the genetic contribution
to the aetiology of self-reported eating disorders in a sample of representative twins.Method. A population cohort of 34142 young Danish twins was screened for eating disorders by
a mailed questionnaire.Results. Concordance rates differed significantly across monozygotic and dizygotic twin pairs for
broadly defined self-reported anorexia nervosa and bulimia nervosa. Heritability estimates of 0·48,
0·52 and 0·61 respectively were estimated for narrow and broad definitions of self-reported anorexia
nervosa and for self-reported bulimia nervosa.Conclusions. There is a genetic contribution to the aetiology of self-reported eating disorders in the
general population. The relationship between self-reported and clinical eating disorder remains to
be examined.
Deriving behavioural phenotypes in an international, multi-centre study of eating disorders
Authors: THE PRICE FOUNDATION COLLABORATIVE GROUP  
Published: July 2002

Background. An international, multi-site study funded by the Price Foundation has collected 237 affected relative pairs to identify potential genetic factors that may contribute to the pathogenesis of anorexia nervosa (AN). The current report utilized this sample to derive phenotypes from the personality and behavioural traits assessed in a large number of individuals with eating disorders.Methods. Multivariate analytical techniques were used to characterize the relationships among personality (e.g. trait anxiety, perfectionism, harm avoidance, novelty seeking) and behavioural traits (obsessions and compulsions) in individuals with eating disorders (primarily AN; N = 348) and assess the effectiveness of these traits in classifying subjects into diagnostic subtypes.Results. Factor analysis revealed that the most influential factor was one of trait anxiety, harm avoidance, perfectionism, obsessive–compulsive behaviours, and diminished self-directedness, although the precise nature of this factor differed slightly across sites. Discriminant analysis was used to evaluate the utility of these personality/behavioural factors in predicting subdiagnosis. Overall, the misclassification rate was 34 %; however, there was an 80 % rate of accurate classification of those individuals with a diagnosis of restricting-type AN.Conclusions. Trait anxiety, harm avoidance, perfectionism, obsessive–compulsive behaviours and diminished self-directedness may best be conceptualized as parts of the same underlying construct among individuals with eating disorders, particularly AN. These personality and behavioural traits were also found to be of some utility in classifying eating disordered individuals into diagnostic subgroups, particularly those with restricting-type AN. We expect these phenotypic findings to benefit our ongoing search for genetic loci underlying the liability to eating disorders.
Abnormal neural response to feedback on planning
and guessing tasks in patients with unipolar depression
Authors: ELLIOTT R. , SAHAKIAN B. J. , MICHAEL A. , PAYKEL E. S. , DOLAN R. J. 
Published: July 2002

Background. It has been suggested that patients with
unipolar depression show abnormal responses
to negative feedback in the performance of cognitive tasks. Positron emission
tomography (PET)
has previously identified blood flow abnormalities in depressed patients
during cognitive
performance. We have also used PET to identify regions where there is
differential neural response
to performance feedback in normal volunteers. In this study we aimed to
test the hypothesis that
blood flow in these regions, the medial caudate and ventromedial prefrontal
cortex, would be
abnormal in depressed patients.Methods. Six patients with unipolar depression and six matched

controls were scanned using PET
while performing cognitive tasks in the presence and absence of feedback.Results. Compared with controls, depressed patients failed
to
show significant activation in the
medial caudate and ventromedial orbitofrontal cortex. Blood flow was lower
and a differential
response, observed in normals, under different task and feedback conditions
was not seen in the
patients.Discussion. The findings suggest that the behavioural response

to feedback in depressed patients is
associated with an abnormal neural response within the medial caudate and
ventromedial
orbitofrontal cortex, regions implicated in reward mechanisms. We argue
that the observed
abnormalities may depend on a combination of psychological factors, with
both cognitive and
emotive components.
Randomized trial of physical exercise alone or
combined with bright light on mood and health-related quality of life
Authors: PARTONEN T. , LEPPÄMÄKI S. , HURME J. , LÖNNQVIST J. 
Published: July 2002

Background. So-called atypical depressive symptoms (carbohydrate
craving, prolonged sleep,
weight gain, increased appetite) frequently emerge in association with
low illumination to which
people are ordinarily exposed indoors, or even outdoors at extreme latitudes
in wintertime. Our
objective was to analyse the effect of physical exercise alone or combined
with bright light on mood
and the health-related quality of life during winter.Methods. We carried out a randomized controlled trial on 120
indoor employees in southern
Finland between November and January. The subjects were allocated to supervised
fitness training
under bright (2500–4000 lx) or ordinary (400–600 lx) light
conditions in a gym 2–3 times weekly for
8 weeks, or supervised relaxation training once a week over the same period
as active placebo. We
collected questionnaire data on the changes in mood and health-related
quality of life after 4 and
8 weeks of training, and after 4 months follow-up.Results. Fitness training in bright light resulted in greater
relief from atypical depressive symptoms
and more vitality than in ordinary room light. Compared with relaxation
alone, the former regime
improved general mental health and social functioning in addition to the
improvement in depressive
symptoms and vitality, whereas the latter only increased vitality.Conclusions. Supervised physical exercise combined with exposure
to bright light appears to be an
effective intervention for improving mood and certain aspects of the health-related
quality of life in
wintertime. This effect appears unrelated to the history of season-dependent
symptoms, being
noticeable among healthy individuals.
Reduced activation and altered laterality in two neuroleptic-naive
catatonic patients during a motor task in functional MRI
Authors: NORTHOFF G. , BRAUS D. F. , SARTORIUS A. , KHORAM-SEFAT D. , RUSS M. , ECKERT J. , HERRIG M. , LESCHINGER A. , BOGERTS B. , HENN F. A. 
Published: July 2002

Background. Catatonia, a symptom complex with motor, affective and cognitive symptoms seen in
a variety of psychotic conditions and with organic disease, was examined using a motor task
using functional magnetic resonance imaging (fMRI).Methods. Two acute catatonic patients and two age- and sex-matched healthy controls performed
sequential finger opposition (SFO) after being medicated with 2 mg of lorazepam (i.v.). Functional
magnetic resonance images were collected using a gradient echo pulse sequence (EPI).Results. Patients with catatonia showed reduced motor activation of the contralateral motor cortex
during SFO of the right hand, ipsilateral activation was similar for patients and controls. There were
no differences in the activation of the SMA. During left hand activation the right-handed catatonic
patients showed more activation in the ipsilateral cortex, a reversal from the normal pattern of
activation in which the contralateral side shows four to five times more activation than the
ipsilateral side.Conclusions. In catatonic patients there is a decreased activation in motor cortex during a motor
task compared to matched medicated healthy controls. In addition activation of the non-dominant
side, left-handed activity in right-handed patients, results in a total reversal of the normal pattern
of lateral activation suggesting a disturbance in hemispheric localization of activity during a
catatonic state.
Age differences in depression and anxiety symptoms:
a structural equation modelling analysis of data from
a general population sample
Authors: CHRISTENSEN H. , JORM A. F. , MACKINNON A. J. , KORTEN A. E. , JACOMB P. A. , HENDERSON A. S. , RODGERS B. 
Published: July 2002

Background. There is debate as to whether the elderly
are really at lower risk for depressive
disorders, or whether endorsement of symptoms is artefactually low. The
present paper assesses the
effects of age on anxiety and depression, and examines whether age has
direct effects on self-report
of individual symptoms independent of its effect on the underlying dimensions
of anxiety and
depression.Methods. Structural equation modelling was used to assess the
structure of the items and their
associations with age and a number of demographic variables. The sample
of 2622 participants aged
between 18 and 79 years from Canberra (Australia) was drawn from the Electoral
Roll. Two
instruments were used: the anxiety and depression scales of Goldberg et
al. (1988) and the Personal
Disturbance Scale from the DSSI of Bedford et al. (1976).Results. Both scales were found to fit satisfactorily to a
two factor model. Age correlated negatively
with depression. After controlling for the effects of gender, marital status,
education and financial
difficulty, direct effects of age were found on items from both instruments,
indicating that certain
depression items were associated with a differential probability of endorsement
in older people, even
when the level of depression was equal to that of younger people. Items
with direct age effects
reflected physical (feeling slowed down; waking early) and psychological
(hopeless about the future)
components of depression. Direct effects of age on items from both anxiety
scales were also found.Conclusions. The nature of the depression and anxiety experienced
by younger and older people may
differ qualitatively. Depression may be associated with an increase in
somatic symptoms linked to
physical changes and to an increase in endorsement of items which reflect
the narrowing of
opportunities in the long-term.
The difference in patterns of motor and cognitive
function in chronic fatigue syndrome and severe depressive illness
Authors: LAWRIE S. M. , MacHALE S. M. , CAVANAGH J. T. O. , O'CARROLL R. E. , GOODWIN G. M. 
Published: July 2002

Background. Chronic fatigue syndrome (CFS) and major depressive disorder (MDD) share many
symptoms and aetiological factors but may have different neurobiological underpinnings. We
wished to determine the profile of the biological variables disturbed in CFS and MDD, and identify
any critical factors that differentiate the disorders.Methods. Thirty patients with CFS, 20 with MDD and 15 healthy controls – matched group-wise
for age and sex – were recruited. Subjects were given a detailed battery of motor and cognitive tests,
including measures of psychomotor speed, memory and maximal voluntary muscle contraction in
both the morning and evening that were balanced to avoid order effects.Results. CFS patients generally performed worse on cognitive tests than healthy controls, but better
than patients with MDD. Both patient groups had markedly impaired motor function compared
with healthy controls. MDD subjects showed a significantly greater diurnal improvement in
maximal voluntary contraction than healthy controls.Conclusions. Patients with CFS and MDD show similarly substantial motor impairment, but
cognitive deficits are generally more marked in MDD. Diurnal changes in some functions in MDD
may differentiate the disorder from CFS.
Community-based mental health care: to what extent
are service costs associated with clinical, social and
service history variables?
Authors: BONIZZATO P. , BISOFFI G. , AMADDEO F. , CHISHOLM D. , TANSELLA M. 
Published: July 2002

Background. The growing movement in many European countries towards capitation-based systems for financing mental health care has generated increasing interest in developing appropriate models capitation formulae. The aims of the study were: to detect and compare any differences in service costs between patients with different diagnoses; and to analyse the associations between
patient characteristics and service costs.Methods. All patients in contact with the South-Verona Community Mental Health Service during the last quarter of 1996 were included in the study. Clinical and service-related variables were collected at first index contact; 3 months later, patients were interviewed using the Client Services Recipient Interview. For those who completed both the clinical assessments and the services receipt schedule (N = 339), 1-year psychiatric and non-psychiatric direct care costs were calculated. Weighted backward regression analyses were performed.Results. The most significant variables associated with psychiatric costs were: admission to hospital in the previous year; intensity and duration of previous contacts with South-Verona CMHS; being unemployed; having a diagnosis of affective disorder; and, Global Assessment of Functioning score. The final model explained 66% of the variation in costs of psychiatric care and 13% of variation in non-psychiatric medical costs. Conclusions. The model presented in this study explains a higher degree of cost variance than previously published studies. In community-based services more resources are targeted towards the most disabled patients. Previous psychiatric history (number of admissions in the previous year and intensity of psychiatric contacts lifetime) is strongly associated with psychiatric costs.
Attempted suicide in west London, II. Inter-group comparisons
Authors: BHUGRA D. , BALDWIN D. S. , DESAI M. , JACOB K. S. 
Published: July 2002

Background. Previous studies of attempted suicide have suggested that cultural and social factors
play a significant role in the causation of deliberate self-harm.Method. In order to measure elements of culture conflict two inter-group comparisons were
undertaken. In the first, 27 Asian women who had presented to hospital services following
attempted suicide (Asian group) were matched with a group of similar age Asian women attending
GP surgeries for other reasons (Asian GP attenders group). The second comparison was between
the Asian and 46 White attempters.Results. On comparing Asian attempters with Asian GP attenders group the former were more
likely to have a history of previous suicidal behaviour, to have a psychiatric diagnosis, and be
unemployed. Their parents were more likely to have arrived in the United Kingdom at an older age.
In addition, those who attempted suicide were more likely to have been in an inter-racial
relationship and to have changed religions. In the second inter-group comparison, the characteristics
of Asian and White suicide attempt patients were examined. White attempters were more likely to
have mental illness, and were more likely to use alcohol as part of the method of attempted suicide.
By contrast, Asian attempters had experienced life events pertaining to relationships, took fewer
tablets and yet expressed greater regret at not succeeding in the attempt.Conclusions. Although numbers are small, social stress and other cultural factors play an important
role in the act of deliberate self-harm.
Sorting out additions to the understanding of cognition during sleep
Authors: Moorcroft William H. 
Published: July 2002

The target articles by Hobson et al., by Solms, and by Nielsen can be combined to further our understanding of the neurological basis of dreaming during REM and, notably, NREM sleep. Revonsuo adds to our understanding of the function of dreams from the perspective of behavioral biology but overstates its importance. Vertes & Eastman fail in their effort to discount memory enhancement as a function of REM sleep.[Hobson et al.; Nielsen; Revonsuo; Solms; Vertes & Eastman]
Critical brain characteristics to consider in developing dream and memory theories
Authors: Morrison Adrian R. , Sanford Larry D. 
Published: July 2002

Dreaming in sleep must depend on the activity of the brain as does cognition and memory in wakefulness. Yet our understanding of the physiological subtleties of state differences may still be too primitive to guide theories adequately in these areas. One can state nonetheless unequivocally that the brain in REM is poorly equipped to practice for eventualities of wakefulness through dreaming, or for consolidating into memory the complex experiences of that state.[Hobson et al., Nielsen, Solms, Vertes & Eastman, Revonsuo]
Search activity: A key to resolving contradictions in sleep/dream investigation
Authors: Rotenberg V. S. 
Published: July 2002

The target articles on sleep and dreaming are discussed in terms of the concept of search activity integrating different types of behavior, body resistance, REM sleep/dream functions, and the brain catecholamine system. REM sleep may be functionally sufficient or insufficient, depending on the dream scenario, the latter being more important than the physiological manifestation of REM sleep. REM sleep contributes to memory consolidation in the indirect way.[Nielsen; Revonsuo; Solms; Vertes & Eastman]
COST-EFFECTIVENESS OF TARGETED SCREENING FOR ABDOMINAL AORTIC ANEURYSM
Authors: Pentikäinen Tuomo Johannes , Sipilä Teemu , Rissanen Pekka , Soisalon-Soininen Sari , Salo Jarmo 
Published: July 2002

Objectives: This article reports a cost-effectiveness analysis of
targeted screening for abdominal aortic aneurysm (AAA). A major emphasis was
on the estimation of distributions of costs and effectiveness.Methods: We performed a Monte Carlo simulation using C programming
language in a PC environment. Data on survival and costs, and a majority of
screening probabilities, were from our own empirical studies. Natural history
data were based on the literature.Results: Each screened male gained 0.07 life-years at an
incremental cost of FIM 3,300. The expected values differed from zero very
significantly. For females, expected gains were 0.02 life-years at an
incremental cost of FIM 1,100, which was not statistically significant.
Cost-effectiveness ratios and their 95% confidence intervals were FIM 48,000
(27,000–121,000) and 54,000 (22,000–∞) for males and
females, respectively. Sensitivity analysis revealed that the results for
males were stable. Individual variation in life-year gains was high.Conclusions: Males seemed to benefit from targeted AAA screening,
and the results were stable. As far as the cost-effectiveness ratio is
considered acceptable, screening for males seemed to be justified. However,
our assumptions about growth and rupture behavior of AAAs might be improved
with further clinical and epidemiological studies. As a point estimate,
females benefited in a similar manner, but the results were not statistically
significant. The evidence of this study did not justify screening of females.