bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mean-flow scaling of turbulent pipe flow
Authors: ZAGAROLA MARK V. , SMITS ALEXANDER J. 
Published: July 2002

Measurements of the mean velocity profile and pressure drop were
performed in a fully
developed, smooth pipe flow for Reynolds numbers from 31×103

to 35×106. Analysis
of the mean velocity profiles indicates two overlap regions: a power law
for
60<y+<500 or
y+<0.15R+, the outer limit
depending on whether the Kármán number R+

is greater or less than 9×103; and a log law for
600<y+<0.07R+. The log law
is only
evident if the Reynolds number is greater than approximately 400×103

(R+>9×103). Von Kármán's

constant was shown to be 0.436 which is consistent with the friction
factor data and the mean velocity profiles for
600<y+<0.07R+, and the additive

constant was shown to be 6.15 when the log law is expressed in inner scaling
variables.A new theory is developed to explain the scaling in both overlap regions.
This theory
requires a velocity scale for the outer region such that the ratio of the
outer velocity
scale to the inner velocity scale (the friction velocity) is a function
of Reynolds number
at low Reynolds numbers, and approaches a constant value at high Reynolds
numbers.
A reasonable candidate for the outer velocity scale is the velocity deficit
in the pipe,
UCL−Ū, which is a
true outer velocity scale, in contrast to the friction velocity which
is a velocity scale associated with the near-wall region which
is ‘impressed’ on the outer
region. The proposed velocity scale was used to normalize the velocity
profiles in the
outer region and was found to give significantly better agreement between
different
Reynolds numbers than the friction velocity.The friction factor data at high Reynolds numbers were found to be significantly

larger (>5%) than those predicted by Prandtl's relation. A new
friction factor relation
is proposed which is within ±1.2% of the data for Reynolds
numbers between 10×103 and 35×106,
and includes a term to account for the near-wall velocity profile.
Near-critical reflection of internal waves
Authors: DAUXOIS THIERRY , YOUNG W. R. 
Published: July 2002

Using a matched asymptotic expansion we analyse the two-dimensional, near-critical
reflection of a weakly nonlinear internal gravity wave from a sloping boundary in
a uniformly stratified fluid. Taking a distinguished limit in which the amplitude
of the incident wave, the dissipation, and the departure from criticality are all
small, we obtain a reduced description of the dynamics. This simplification shows
how either dissipation or transience heals the singularity which is presented by the
solution of Phillips (1966) in the precisely critical case. In the inviscid critical case, an
explicit solution of the initial value problem shows that the buoyancy perturbation
and the alongslope velocity both grow linearly with time, while the scale of the
reflected disturbance is reduced as 1/t. During the course of this scale reduction, the
stratification is ‘overturned’ and the Miles–Howard condition for stratified shear flow
stability is violated. However, for all slope angles, the ‘overturning’ occurs before the
Miles–Howard stability condition is violated and so we argue that the first instability
is convective.Solutions of the simplified dynamics resemble certain experimental visualizations
of the reflection process. In particular, the buoyancy field computed from the analytic
solution is in good agreement with visualizations reported by Thorpe & Haines
(1987).One curious aspect of the weakly nonlinear theory is that the final reduced description
is a linear equation (at the solvability order in the expansion all of the
apparently resonant nonlinear contributions cancel amongst themselves). However,
the reconstructed fields do contain nonlinearly driven second harmonics which are
responsible for an important symmetry breaking in which alternate vortices differ in
strength and size from their immediate neighbours.
Dissipation-range geometry and scalar spectra in
sheared stratified turbulence
Authors: SMYTH WILLIAM D. 
Published: July 2002

Direct numerical simulations of turbulence resulting from Kelvin–Helmholtz
instability in stratified shear flow are used to examine the geometry of the dissipation
range in a variety of flow regimes. As the buoyancy and shear Reynolds numbers that
quantify the degree of isotropy in the dissipation range increase, alignment statistics
evolve from those characteristic of parallel shear flow to those found previously in
studies of stationary, isotropic, homogeneous turbulence (e.g. Ashurst et al. 1987;
She et al. 1991; Tsinober et al. 1992). The analysis yields a limiting value for the
mean compression rate of scalar gradients that is expected to be characteristic of all
turbulent flows at sufficiently high Reynolds number.My main focus is the value of the constant q that appears in both the Batchelor
(1959) and Kraichnan (1968) theoretical forms for the passive scalar spectrum. Taking
account of the effects of time-dependent strain, I propose a revised estimate of q,
denoted qe, which appears to agree with spectral shapes derived from simulations
and observations better than do previous theoretical estimates. The revised estimate
is qe = 7.3±4, and is expected to be valid whenever the buoyancy Reynolds number
exceeds O(102). The Kraichnan (1968) spectral form, in which effects of intermittency
are accounted for, provides a better fit to the DNS results than does the Batchelor
(1959) form.
Assessment of errors in cetacean diet analysis: in vitro digestion of otoliths
Authors: Wijnsma G. , Pierce G.J. , Santos M.B. 
Published: July 2002

Research into the feeding habits of cetaceans has traditionally relied on examining samples taken from the digestive tracts of commercially caught or stranded and by-caught animals. This depends on the identification and measurement of hard parts such as fish otoliths. Otoliths are often partially digested in the stomach, making quantitative estimates of fish size from otolith size biased.As a preliminary attempt to quantify the size reduction of otoliths found in the stomachs of small cetaceans, an in vitro digestion experiment was carried out. Otoliths of herring, whiting, poor cod and haddock were digested at 37°C, pH=3·6, and measured every 60 min.Linear regressions relating otolith size to digestion time and original size generally provided an adequate description of the time course of size reduction. The parameter that changed most rapidly due to digestion was otolith thickness. Differences in digestion rates between species reflect the general robustness and shape of the otoliths.A simulation using actual dietary data showed that the overall diet composition was not radically changed by accounting for otolith digestion, although the apparent contribution of herring increased as the assumed digestion time is increased, because herring otoliths were the most susceptible to digestion.
Agents and their Actions
Authors: ALVAREZ MARIA , HYMAN JOHN 
Published: July 2002

In the past thirty years or so, the doctrine that actions are events has become an essential, and sometimes unargued, part of the received view in the philosophy of action, despite the efforts of a few philosophers to undermine the consensus. For example, the entry for Agency in a recently published reference guide to the philosophy of mind begins with the following sentence:A central task in the philosophy of action is that of spelling out the differences between events in general and those events that fall squarely into the category of human action.There is no consensus about what events are. But it is generally agreed that, whatever events may prove to be, actions are a species or a class of events.
We believe that the received view is mistaken: actions are not events. We concede that for most purposes, the kind of categorial refinement which is involved in either affirming or denying that actions are events is frankly otiose. Our common idiom does not stress the difference between actions and events, at least not in general terms, because it has no need to. Perhaps it sounds a little odd to say that some events are performed; but if we balked at describing, say, the abdication of Edward VIII as one of the politically significant events in Britain in 1936, it could not be for metaphysical reasons. And since actions, like events, are datable — though often, as we shall see, only imprecisely — actions are said to take place and to occur. But an important class of actions consist in moving something; indeed, according to many philosophers, every action consists in moving something. And when we consider actions of this sort from a theoretical point of view it becomes imperative to distinguish between actions and events. Or so we shall argue.
Colour: Physical or Phenomenal?
Authors: WAHL RUSSELL , WESTPHAL JONATHAN 
Published: July 2002

We wish to defend Jonathan Westphal's view that colour is complex against a recent ‘phenomenological’ criticism of Eric Rubenstein. There is often thought to be a conflict between two kinds of determinants of colour, physical and phenomenal. On the one hand there are the complex physical facts about colour, such as the determination of a surface colour by an absorption spectrum. There is also, however, the fact that the apparently simple phenomenological quality of what is seen is a function of the physiological and psychological state of the viewing subject. Should the physical trump the phenomenal, or is it the other way round?Much of the phenomenal variation of colour, however, is explained by physical facts. There is a physics and a psychophysics of colour. Colours appear, to the colour scientists at least, to be in some sense objective, a sense not explained by the view that they are purely phenomenal. Taking physics and psychophysics into account will mean rejecting the claim that the content of what our concepts of colours are concepts of is exhausted by the purely phenomenal, or that we can determine these concepts simply by gazing at a colour. Taking account of physics will lead, as Westphal argued, instead to a view about white and the other colour terms like Putnam's account of gold. Necessary truths about colours cannot be explained without reference to the logic of the compossibility of what is given in reflection and absorption spectra, the analogue of H2O.
Predicting depression in women: the role of past and

present vulnerability
Authors: BIFULCO A. , BROWN G. W. , MORAN P. , BALL C. , CAMPBELL C. 
Published: July 2002

Background. A prospective study, covering just over a

1-year period, sought to confirm an earlier

finding that around 40% of women who experience a severe life event

in the presence of two

ongoing psychosocial vulnerability factors, (negative close

relationships and low self-esteem) will

develop a major depressive episode. Distal risk factors were examined

to see if they improved prediction.Methods. A population sample of 105 mainly working-class

mothers with vulnerability and without

depression were interviewed three times over a 14-month period to

date the occurrence of severe life

events and onset of major depression. Degree of vulnerability was

assessed at first contact together

with distal risk in terms of childhood neglect/abuse

and any earlier episodes of depression.Results. Thirty-seven per cent of these vulnerable women

became depressed in the study period. The

majority experienced a severe life event, and of these, 48% had onsets.

Contrary to expectation, risk

was only a little less among those with just one of the two

vulnerability factors. Two-thirds of

women with an onset had been depressed in previous years. Although

this was associated with

increased risk, the effect was greatest for those who had experienced

an episode before age 20. A

relationship between childhood neglect/abuse and onset was

entirely accounted for by such early depression.Conclusion. An aetiological model of depression outlined

in earlier research was confined with a new

factor of teenage depression shown to increase risk of onset.
Spouse similarity for lifetime psychiatric history in the general
population
Authors: GALBAUD DU FORT G. , BLAND R. C. , NEWMAN S. C. , BOOTHROYD L. J. 
Published: July 2002

Background. Most studies of spouse similarity for
psychiatric disorders have focused on clinical
samples and are thus limited by selection bias. This study is, to our knowledge,
the first
comprehensive investigation of spouse similarity for lifetime psychiatric
history in a general
population sample using standardized diagnostic criteria.Methods. We studied 519 pairs of spouses residing in Edmonton,

Canada who completed the
Diagnostic Interview Schedule psychiatric interview. In each pair,
one spouse belonged to a random
subsample of persons who had participated in a large population survey
and was re-interviewed.
Association between spouses for lifetime DSM-III psychiatric
disorders was analysed with bivariate
and multivariate logistic regression analyses.Results. We observed significant spousal association for lifetime

presence of affective disorders and
for the spectrum of antisocial personality and addiction
disorders. Antisocial personality in one
spouse was also associated with anxiety disorders in the other
spouse, namely post-traumatic stress
disorder in wives and phobia in husbands; similarly, drug abuse/dependence
in wives was
associated with generalized anxiety in husbands and male drug abuse/dependence

was associated with female post-traumatic stress disorder. Dysthymia in
wives was
associated with generalized anxiety and post-traumatic stress disorder
in husbands.Conclusions. The existence of associations between spouses
for
the presence of psychiatric disorders,
either similar or different, has significant implications for
both clinicians and researchers. Future
research should aim at exploring the aetiological mechanisms of these associations.
Cognitive processes in auditory hallucinations:
attributional biases and metacognition
Authors: BAKER CAROLINE A. , MORRISON ANTHONY P. 
Published: July 2002

Background. Cognitive models suggest that auditory
hallucinations are experienced when mental
events are misattributed to an external source; therefore, this study was
designed to examine
attributional biases in patients experiencing auditory hallucinations.

The study also examined the role of metacognitive beliefs in the experience
of auditory
hallucinations, as some theories have
implicated metacognition in the development and maintenance of auditory
hallucinations.Methods. Fifteen participants with a diagnosis of
schizophrenia experiencing auditory
hallucinations were compared with 15 non-hallucinating schizophrenics and
15 non-psychiatric
control subjects on several measures, including an immediate source monitoring
task and a
questionnaire assessing metacognitive beliefs.Results. Results indicated that patients experiencing
hallucinations exhibited the predicted bias
towards misattributing internal events to an external source, as
measured by ratings of internality
of responses in a word association task. All groups had lower
perceived levels of internality and
control for emotionally salient words, which provides further evidence
for the importance of
emotional content in hallucinations. Patients experiencing
hallucinations were found to score higher
than the other two groups on metacognitive beliefs about uncontrollability

and danger and positive
beliefs about worry. In addition, a logistic regression analysis showed
that beliefs about
uncontrollability and danger were predictive of whether subjects
experienced auditory hallucinations or not.Conclusions. These results offer considerable support to
cognitive bias models of auditory
hallucinations, particularly those that implicate metacognition.
Errorless learning and the cognitive rehabilitation of
memory-impaired schizophrenic patients
Authors: O'CARROLL R. E. , RUSSELL H. H. , LAWRIE S. M. , JOHNSTONE E. C. 
Published: July 2002

Background. In recent years, evidence has accumulated
that a significant proportion of schizophrenic
patients have severe memory impairment, which cannot be attributed to the
effects of medication,
chronicity or institutionalization. Our group has demonstrated that memory
impairment is
associated with poor psychosocial outcome and treatment resistance. Work
on the classical amnesic
syndrome has suggested that memory training is facilitated by adopting
an ‘errorless learning’
approach, where subjects do not experience failure during learning. This
is based on the theory that
the preserved implicit memory of amnesic patients results in implicitly
remembered incorrect
responses interfering with target items, in the absence of a functioning
explicit memory system to
allow differentiation.Method. We compared three groups of subjects, memory-impaired
schizophrenic patients, memory
unimpaired schizophrenic patients and healthy controls.Results. An errorless learning approach conferred a significant
advantage on the memory-impaired
schizophrenic group, bringing their performance up to the level of both
control groups. In contrast,
adopting a traditional trial and error, or errorful approach resulted in
markedly impaired
performance in the memory-impaired schizophrenic group only.Conclusions. We conclude that errorless learning approaches
may be worthy of further evaluation
in the cognitive rehabilitation of memory-impaired schizophrenic patients.
Alteration of the platelet serotonin transporter in romantic love
Authors: MARAZZITI D. , AKISKAL H. S. , ROSSI A. , CASSANO G. B. 
Published: July 2002

Background. The evolutionary consequences of love are so important that there must be some long-established biological process regulating it. Recent findings suggest that the serotonin (5-HT)
transporter might be linked to both neuroticism and sexual behaviour as well as to
obsessive–compulsive disorder (OCD). The similarities between an overvalued idea, such as that
typical of subjects in the early phase of a love relationship, and obsession, prompted us to explore
the possibility that the two conditions might share alterations at the level of the 5-HT transporter.Methods. Twenty subjects who had recently (within the previous 6 months) fallen in love, 20
unmedicated OCD patients and 20 normal controls, were included in the study. The 5-HT
transporter was evaluated with the specific binding of 3H-paroxetine
(3H-Par) to platelet membranes.Results. The results showed that the density of
3H-Par binding sites was significantly lower in
subjects who had recently fallen in love and in OCD patients than in controls.Discussion. The main finding of the present study is that subjects who were in the early romantic
phase of a love relationship were not different from OCD patients in terms of the density of the
platelet 5-HT transporter, which proved to be significantly lower than in the normal controls. This
would suggest common neurochemical changes involving the 5-HT system, linked to psychological
dimensions shared by the two conditions, perhaps at an ideational level.
Translating ethical principles into outcome measures for mental
health service research
Authors: THORNICROFT GRAHAM , TANSELLA MICHELE 
Published: July 2002

Background. Mental health service research continues to use only outcome measures that are
available rather than develop measures that are important. This paper argues that it is necessary
to select and then define a set of ethical principles that can be operationalized and validated as
outcome measures to provide a wider balance of information for health policy and clinical service
decisions.Methods. The method used is to adopt a five stage procedure: (i) to select ethical principles most
directly relevant for mental health services and their evaluation at the local level; (ii) to propose
definitions of these principles; (iii) to validate these definitions; (iv) to translate the defined
principles into operationalized outcome measures; and (v) to use these outcome measures in mental
health services research, within the context of evidence-based medicine.Results. We address steps (i) and (ii) of this five-stage procedure. Nine principles are selected and
defined: autonomy, continuity, effectiveness, accessibility, comprehensiveness, equity, accountability,
coordination and efficiency. These principles can together be referred to as the three ACEs.Conclusions. Of these nine principles, only two (effectiveness and efficiency) have so far been fully
translated into quantitative outcome measures, upon which the evidence-based medicine approach
depends. We propose that further concepts also be developed into a more complete multi-
dimensional range of fully operationalized outcome measures.
The perception of self-produced sensory stimuli in patients with auditory hallucinations and passivity experiences: evidence for a breakdown in self-monitoring
Authors: BLAKEMORE S.-J. , SMITH J. , STEEL R. , JOHNSTONE E. C. , FRITH C. D. 
Published: July 2002

Background. To test the hypothesis that certain psychotic symptomatology is due to a defect in self- monitoring, we investigated the ability of groups of psychiatric patients to differentiate perceptually between self-produced and externally produced tactile stimuli.Methods. Responses to tactile stimulation were assessed in three groups of subjects: schizophrenic patients; patients with bipolar affective disorder or depression; and normal control subjects. Within the psychiatric groups subjects were divided on the basis of the presence or absence of auditory hallucinations and/or passivity experiences. The subjects were asked to rate the perception of a tactile sensation on the palm of their left hand. The tactile stimulation was either self-produced by movement of the subject's right hand or externally produced by the experimenter.Results. Normal control subjects and those psychiatric patients with neither auditory hallucinations nor passivity phenomena experienced self-produced stimuli as less intense, tickly and pleasant than identical, externally produced tactile stimuli. In contrast, psychiatric patients with these symptoms did not show a decrease in their perceptual ratings for tactile stimuli produced by themselves as compared with those produced by the experimenter. This failure to show a difference in perception between self-produced and externally produced stimuli appears to relate to the presence of auditory hallucinations and/or passivity experiences rather than to the diagnosis of schizophrenia.Conclusions. We propose that auditory hallucinations and passivity experiences are associated with an abnormality in the self-monitoring mechanism that normally allows us to distinguish self-produced from externally produced sensations.