bluuebunny/crossref_metadata_2025 huggingface dataset:
Validation of a chart to estimate true Schistosoma

mansoni prevalences from simple egg counts
Authors: DE VLAS S. J. , ENGELS D. , RABELLO A. L. T. , OOSTBURG B. F. J. , VAN LIESHOUT L. , POLDERMAN A. M. , VAN OORTMARSSEN G. J. , HABBEMA J. D. F. , GRYSEELS B.
Published: July 2002

Schistosoma mansoni egg counts by faecal examination
vary

considerably

and are not very sensitive, so prevalences are

underestimated. The distribution of egg counts can adequately be described
by a

stochastic model which distinguishes

variation in counts between persons and variation in repeated counts within
a

person. Based on this model a pocket chart

has been developed which predicts the proportion of individuals harbouring
at

least 1 S. mansoni worm pair – the ‘true

prevalence’ – from a simple single survey prevalence and geometric
mean egg

count (using common duplicate 25 mg

Kato–Katz smears). The current paper describes the validation of
this chart

by comparing predicted true prevalences with

prevalences observed after 5–7 repeated Kato–Katz faecal examinations

(Burundi), by examination of a large quantity of

stool using the Visser filter (Brazil) or a selective sedimentation–filtration

method (Surinam). Because 5–7 repeated

examinations do not suffice to measure all infections, predictions have
been

made of the cumulative proportion positives

over 5–7 surveys – the ‘approximate true prevalence’
– as well. After dividing

the data into age groups, 12 different subsets

were considered for validation. In all 12 cases, predicted true prevalences
(or

approximate true prevalences for the Burundi

data) agree well with those observed. The overall agreement depends only
slightly

on the assumed relationship between

worm numbers and mean egg counts, with a good fit for a productivity between
0·8

and 4·4 eggs per gramme faeces (EPG)

per worm pair (WP). This interval includes the most plausible value from
the

literature, i.e. 1·0 EPG/WP, which has been

applied in the initial pocket chart. These findings support the validity
of the

chart to predict true prevalences for a wide

range of productivity assumptions, and reinforces the applicability of
its

underlying stochastic model to describe egg count

variation. However, as predictions appear to vary importantly when using
only

part of the data, it is also concluded that

the pocket chart never compensates for limited validity of initial single

survey prevalences and geometric means in consequence of small sample sizes.
The protozoan parasite Perkinsus atlanticus elicits a unique
defensive response in the clam Tapes semidecussatus
Authors: MONTES J. F. , DEL RÍO J. A. , DURFORT M. , GARCÍA-VALERO J.
Published: July 2002

The venerid clams, Tapes decussatus and T. semidecussatus,
develop a singular defensive response to Perkinsus atlanticus
infection. This reaction involves the redifferentiation of recruited granulocytes
and the expression de novo of the
polypeptide p225. To determine whether the association of this defensive
process
with the natural parasitism by P.
atlanticus is unique, the inflammatory response elicited by inoculations
of
bacteria, algae and non-viable P. atlanticus pre-zoosporangia
in the
clam T. semidecussatus was shown. Inoculated areas were heavily
infiltrated
by granulocytes and
delimited by myofibroblast-like cells and extracellular matrix. While bacteria
and
algae were phagocytosed by the
infiltrated granulocytes, pre-zoosporangia were not. After 40 days, neither
cell
redifferentiation nor the expression of p225
was observed. These findings indicate that both redifferentiation and p225
expression are specifically associated with P.
atlanticus infection. After 5-bromodeoxyuridine administration, only
a few
cells were labelled either in the inoculated zone
or in the cellular reaction around P. atlanticus meronts. Significant
differences between untreated and inoculated groups
were observed in the epicardic connective tissue soon after injection.
These
results suggest that this anatomical region
could be the main site of haemocyte proliferation stimulated after inoculation
of foreign bodies in T. semidecussatus.
The relationship between numbers of larvae recovered
from the brain of Toxocara canis-infected mice and social
behaviour and anxiety in the host
Authors: COX D. M. , HOLLAND C. V.
Published: July 2002

The effect of the nematode Toxocara canis on social
behaviour and anxiety levels of adult male outbred (LACA) mice was
examined following infection with a single dose of 2000 ova. The actual

number of larvae recovered from the brain of each
individual mouse was determined after behavioural testing. The effect of

the parasite on mouse behaviour was analysed
by both the initial dose administered (i.e. infected versus control)
and the degree of infection in the brain. There was
substantial variation in the number of larvae recovered from the
brains of the individual mice and the magnitude of
behavioural change was associated with the level of infection.
Examination of social behaviour for both analyses revealed
that the infection reduced levels of aggressive behaviour and increased

levels of flight and defensive behaviours. High
infection in the brain induced the greatest degree of behavioural change

which decreased in mice with lower infections.
In contrast the analysis of anxiety levels in mice by initial dose
administered revealed no difference between infected and
control mice. Mice with low infection in the brain, however, displayed
a
greater level of risk behaviour by spending more
time in the vicinity of a predator odour and in the light area of a
light/dark paradigm than control or high infection mice.
The results suggest that the behaviour of mice infected with T. canis

is influenced by the number of larvae accumulated
in the brain. This may have important consequences for the conclusions
drawn
on the effect of this parasite on murine behaviour.
Gross anatomy of the muscle systems of Fasciola hepatica

as visualized by phalloidin-fluorescence and confocal microscopy
Authors: MAIR G. R. , MAULE A. G. , SHAW C. , JOHNSTON C. F. , HALTON D. W.
Published: July 2002

Neuropeptides, biogenic amines and acetylcholine are expressed
abundantly
within the nervous systems of parasitic
flatworms, and are particularly evident in the innervation of the musculature.

Such associations have implicated the
nervous system in locomotion, host attachment and reproductive co-ordination.

Information on the muscle systems of
parasitic flatworms is generally sparse, in particular those muscles
associated with the reproductive system, intestinal tract
and attachment apparatus. Also, the use of sectioned material has left

description of the 3-dimensional organization of the
musculature largely unrecorded. Using fluorescein isothiocyanate
(FITC)-labelled phalloidin as a site-specific probe for
filamentous actin, applied to whole-mount preparations of adult
Fasciola hepatica and examined by confocal scanning laser
microscopy, the present work reports on the organization of the major
muscle systems in this trematode parasite. A highly
regular array of outer circular, intermediate longitudinal and inner
diagonal fibres distinguishes the body wall musculature,
which is also involved in the development of both ventral and oral
suckers. Circular fibres dominate the duct walls of the
male and female reproductive systems, whereas the muscles of the
intestinal tract have a somewhat diffuse arrangement
of fibres. An understanding of the structural complexity of the
muscle systems of parasitic flatworms is considered as
fundamental to the interpretation of results from physiological experiments.
Heterogeneities in schistosome transmission dynamics and control
Authors: WOOLHOUSE M. E. J. , ETARD J.-F. , DIETZ K. , NDHLOVU P. D. , CHANDIWANA S. K.
Published: July 2002

We review the theoretical framework for exploring the impact of
individual and spatial heterogeneities in patterns of
exposure and contamination and on the basic reproduction number, R0,
for human schistosomes. Analysis of water contact
data for 5 communities in Zimbabwe and Mali suggests that the impact is
substantial, increasing R0 by factors of up to
6·5, mostly due to highly overdispersed distributions of contact
rates among individuals. Several practical conclusions
emerge: concentration of contacts at a single site should be avoided; the
impact of control targeted at certain sites cannot
be predicted without knowledge of how individuals' contacts are distributed
among sites; control programmes targeted
at individuals or sites contributing most to transmission can be very efficient
but, conversely, will be ineffective if any of
these individuals or sites are missed.
Seasonal variation in development and survival of
Ascaris suum and Trichuris suis eggs on pastures
Authors: LARSEN M. N. , ROEPSTORFF A.
Published: July 2002

Pig faeces were deposited on experimental plots in the spring, summer, autumn and winter to study development and
survival of Ascaris suum and Trichuris suis eggs under outdoor conditions. Faeces were placed either in short grass or 2 cm
below the surface of bare soil, imitating pastures used by nose-ringed, grazing pigs or normally rooting pigs, respectively.
The numbers and developmental stages of the eggs were recorded in faeces and soil for up to 50 weeks post-deposition.
Embryonation took place only during the summer months and seemingly was independent of the microclimate. The
majority of A. suum and T. suis eggs, which are generally considered to be extremely resistant and long-lived, seems to
disappear rather fast. The disappearance rate for A. suum eggs was higher than for T. suis eggs, and both egg types
disappeared significantly faster in the summer months than in the winter months, and when placed in short grass than
when buried in soil (less exposed). We discuss how knowledge on egg development and survival may be used in the
planning of pasture strategies for control of helminth infections in outdoor pigs.
Stochastic simulation and the detection of immunity to
schistosome infections
Authors: CHAN M. S. , MUTAPI F. , WOOLHOUSE M. E. J. , ISHAM V. S.
Published: July 2002

In this paper we address the question of detecting immunity to helminth infections from patterns of infection in endemic
communities. We use stochastic simulations to investigate whether it would be possible to detect patterns predicted by
theoretical models, using typical field data. Thus, our technique is to simulate a theoretical model, to generate the data
that would be obtained in field surveys and then to analyse these data using methods usually employed for field data. The
general behaviour of the model, and in particular the levels of variability of egg counts predicted, show that the model
is capturing most of the variability present in field data. However, analysis of the data in detail suggests that detection of
immunity patterns in real data may be very difficult even if the underlying patterns are present. Analysis of a real data
set does show patterns consistent with acquired immunity and the implications of this are discussed.
Determination of mosquito bloodmeal pH in situ by
ion-selective microelectrode measurement: implications
for the regulation of malarial gametogenesis
Authors: BILLKER O. , MILLER A. J. , SINDEN R. E.
Published: July 2002

Malarial gametocytes circulate in the peripheral blood of the vertebrate host as developmentally arrested intra-erythrocytic
cells, which only resume development into gametes when ingested into the bloodmeal of the female mosquito vector. The
ensuing development encompasses sexual reproduction and mediates parasite transmission to the insect. In vitro the
induction of gametogenesis requires a drop in temperature and either a pH increase from physiological blood pH (ca pH
7·4) to about pH 8·0, or the presence of a gametocyte-activating factor recently identified as xanthurenic acid (XA).
However, it is unclear whether either the pH increase or XA act as natural triggers in the mosquito bloodmeal. We here
use pH-sensitive microelectrodes to determine bloodmeal pH in intact mosquitoes. Measurements taken in the first 30 min
after ingestion, when malarial gametogenesis is induced in vivo, revealed small pH increases from 7·40 (mouse blood) to
7·52 in Aedes aegypti and to 7·58 in Anophěles stephensi. However, bloodmeal pH was clearly suboptimal if compared to
values required to induce gametogenesis in vitro. Xanthurenic acid is shown to extend the pH-range of exflagellation in
vitro in a dose-dependent manner to values that we have observed in the bloodmeal, suggesting that in vivo malarial
gametogenesis could be further regulated by both these factors.
Endoparasite species richness of New Caledonian butterfly fishes: host density and diet matter
Authors: MORAND S. , CRIBB T. H. , KULBICKI M. , RIGBY M. C. , CHAUVET C. , DUFOUR V. , FALIEX E. , GALZIN R. , LO C. M. , LO-YAT A. , PICHELIN S. , SASAL P.
Published: July 2002

Ecological factors may influence the number of parasites encountered and, thus, parasite species richness. These factors
include diet, gregarity, conspecific and total host density, habitat, body size, vagility, and migration. One means of
examining the influence of these factors on parasite species richness is through a comparative analysis of the parasites of
different, but related, host species. In contrast to most comparative studies of parasite species richness of fish, which have
been conducted by using data from the literature, the present study uses data obtained by the investigators. Coral reef
fishes vary widely in the above ecological factors and are frequently parasitized by a diverse array of parasites. We,
therefore, chose to investigate how the above ecological factors influence parasite species richness in coral reef fishes.
We investigated the endoparasite species richness of 21 species of butterfly fishes (Chaetodontidae) of New Caledonia. We
mapped the diet characters on the existing butterfly fish phylogeny and found that omnivory appears to be ancestral.
We also mapped the estimated endoparasite species richness, coded from low to high parasite species richness, on the
existing butterfly fish phylogeny and found that low parasite species richness appears to be associated with the ancestral
state of omnivory. Different dietary and social strategies appear to have evolved more than once, with the exception of
obligate coralivory, which appears to have evolved only once. Finally, after controlling for phylogenetic relationships, we
found that only the percentage of plankton in the diet and conspecific host density were positively correlated with
endoparasite species richness.
Predicting the community prevalence of schistosomiasis mansoni from the prevalence among 7- to 14-year-olds
Authors: RODRIGUES L. C. , WHEELER J. G. , SHIER R. , GUERRA H. L. , PIMENTA F. , LIMA e COSTA M. F. F.
Published: July 2002

The World Health Organization suggested that the prevalence of Schistosoma mansoni among 7- to 14-year-olds be used
to guide treatment strategies in endemic areas. This study explores how well the prevalence in that age group predicted
the overall prevalence in the community in data from stool examinations (Kato–Katz method) from 180000 people in 3
municipalities in Brazil in 1984 and 1985. The median prevalence was higher in 1984, before community treatment was
introduced. There was a strong relationship between the prevalence among 7- to 14-year-olds and the overall prevalence
in the community. We present sensitivities and positive predictive values for the use of prevalence in the indicator group
to select communities for mass treatment as recommended by WHO. For a range of assumptions sensitivity and positive
predictive value were never both above 80%. We suggest that the estimates of validity presented in this paper inform
future evaluations of strategies for S. mansoni control.
The Virtues of Common Sense
Authors: Grant Brian
Published: July 2002

I defend, in this paper, a version of a philosophy of common sense. I have use of some things from Reid's account of these matters, others from Wittgenstein's. Scepticism looms large—as do the questions of arguments for and examples of common sense. At least two different notions of common sense emerge, one of which has often been overlooked by philosophers.
Nagel's Challenge and the Mind-Body Problem
Authors: Harré Rom
Published: July 2002

Nagel has argued that the ‘mind-body’ problem, as traditionally conceived, is insoluble. His challenge to philosophers is to devise a metaphysical scheme that incorporates materialist concepts in describing first person experience and mentalistic concepts in describing third person experience, such that the internal relations between the concepts thereby constructed are necessary. Nagel's own suggestion, a scheme not unlike the ‘underlying process’ schemes of the physical sciences, seems to lead him towards a covert materialism. Progress can be made in meeting the challenge by tackling the problem first by taking the units in each ‘sphere’ to be brains and persons. I show that a metaphysics based on the metaphor of person defined tasks and materially defined tools does satisfy both Nagel's challenge conditions. To devise a scheme for qualia and brain-states I turn back to Locke's presentation of the primary/secondary quality distinction. This depends on the concept of a causal power, grounded in material states of the world. While this scheme is inadequate, a variation, based on Gibson's concept of an affordance, and drawing on Bohr's resolution of the seeming incompatibility between wave and particle ontologies for physics, is promising. The world, whatever it is, affords material states to our perceptual apparatus, and mental states to our proprioceptual apparatus. The mental states/brain states duality is not a duality of types of states, which might stand in causal relations to one another, but is a duality of means of access to two classes of affordances of whatever the world is. There is no mind-body problem in the traditional sense, namely ‘How could a material state cause or be caused by a mental state?’
Trauma and loss as determinants of medically unexplained epidemic illness in a Bhutanese refugee camp
Authors: VAN OMMEREN M. , SHARMA B. , KOMPROE I. , POUDYAL B. N. , SHARMA G. K. , CARDEÑA E. , DE JONG J. T. V. M.
Published: July 2002

Background. We sought to identify personal factors that placed people at risk during an epidemic of medically unexplained illness in a Bhutanese refugee camp in southeastern Nepal.

Methods. We conducted a case–control study, involving 68 cases and 66 controls. Caseness was defined as experiencing at least one attack of medically unexplained fainting or dizziness during the time of the epidemic. We performed hierarchical logistic regression analysis to identify significant predictors of case status.

Results. In terms of Western psychiatric constructs, the illness involved somatoform symptoms of both acute anxiety and dissociation. Sixty per cent reported visual and 28% reported auditory hallucinatory experiences. Cases and controls were similar on all demographic variables, school performance, number of attacks witnessed and psychopathology before the onset of the epidemic. Recent loss, early loss, childhood trauma and pulse-rate were predictors of case status.

Conclusion. We identified trauma, early loss and, especially, recent loss as predictors of attacks during medically unexplained epidemic illness in a Bhutanese refugee community.
The Interview for Recent Life Events
Authors: PAYKEL E. S.
Published: July 2002

Background. This paper summarizes work with the
Interview for Recent Life Events (IRLE), an instrument that has been
used extensively but not previously reported in detail.

Methods. Rationale, development, organization, content,
reliability, validity and applications are reviewed in full.

Results. The instrument covers a comprehensive range of
recent life events, their timing and other important qualities. It has
been found reliable and valid, and has been translated into a number
of languages. It has been used by many research groups in different
countries, in studies of psychiatric patients, medical patients and
subjects in the general population.

Conclusions. The instrument is useful, has been widely
applied and has the necessary qualities for ascertainment of life
events in research studies.
Genetic influences on childhood hyperactivity:
contrast effects imply parental rating bias, not sibling
interaction
Authors: SIMONOFF E. , PICKLES A. , HERVAS A. , SILBERG J. L. , RUTTER M. , EAVES L.
Published: July 2002

Background. Previous twin studies of hyperactivity have

supported a ‘contrast effect’, whereby the
more hyperactive the rating of one twin, the less the rating of the other.

It has not been clear whether
contrast effects occur in the twins' behaviour or in the ratings
made of their behaviour but the
implications for hyperactivity are different under the two models.

Method. We use hyperactivity ratings from mothers and teachers

for 1644 twin pairs in the Virginia
Twin Study of Adolescent Behavioral Development (VTSABD) to explore the
origin of contrast
effects, making use of independent teacher reports in a proportion
of twins. Models were fitted
separately for the two informants and jointly to ratings combined through

a latent variable, using structural equation modelling.

Results. Models for maternal data confirm the contrast effect

previously reported. Teacher ratings
show a different form of bias, with both twin confusion and correlated
errors representing
alternative but not mutually exclusive explanations of the data.
Latent variable modelling of the
joint responses allowed comparison of a model in which the contrast
effect was placed on maternal
ratings, representing bias, versus one in which the contrast occurred
in the underlying ‘true’
phenotype. The fit of the former model was significantly better.

Conclusions. Support is provided for the notion of
contrast effects as a form of rater bias in maternal
hyperactivity ratings. Different bias in teacher reports highlight that
no one report can be
considered a gold standard. The extent to which such biases may
distort information for other data
sources such as sib-pair studies of concordance/discordance is discussed.
The cultural context of caregiving: a comparison
of Alzheimer's caregivers in Shanghai, China
and San Diego, California
Authors: PATTERSON T. L. , SEMPLE S. J. , SHAW W. S. , YU E. , HE Y. , ZHANG M. Y. , WU W. , GRANT I.
Published: July 2002

Background. Systematic comparisons of the psychological
and
physical responses of caregivers of
Alzheimer's disease (AD) patients in the US and China have not been
previously reported.

Methods. Informal caregivers of community dwelling AD patients

in Shanghai, China and
demographically-matched non-caregiving Chinese controls were compared with
a sample of
American caregivers residing in San Diego, California and demographically-matched
American
controls.

Results. Despite some demographic discrepancies, caregivers

from both China and the US were
similar. Caregivers from both cultures reported more depressive symptoms
and more physical
symptoms when compared with non-caregivers. Both groups of caregivers reported
that patients
required similar amounts of care and help with activities of daily
living (ADLs). However, Shanghai
caregivers reported less access to emotional support when compared with
the San Diego sample.
A conceptual model, guided by the stress process model of Pearlin
et al. (1990), was used to explore
multivariate relationships between caregiver characteristics and the physical
and psychological
health of our sample of AD caregivers in Shanghai, China. Results
from a path analytical procedure
revealed that the relationships among these variables and health
outcome did not differ significantly from those observed in the US sample.

Conclusions. Although elderly family members are venerated

in the stereotypical Chinese family
unit, and informal caregiving of disabled family members is socially
mandated, the negative health
consequences of caregiving appear to be similar to those observed among
caregivers in the US.
Assortative mating for major psychiatric diagnoses in
two population-based samples
Authors: MAES H. H. M. , NEALE M. C. , KENDLER K. S. , HEWITT J. K. , SILBERG J. L. , FOLEY D. L. , MEYER J. M. , RUTTER M. , SIMONOFF E. , PICKLES A. , EAVES L. J.
Published: July 2002

Background. Previous studies on assortment for psychiatric
disorders have reported discrepant
findings. We aimed to test whether there is a significant association for
psychiatric diagnoses,
including alcoholism, generalized anxiety disorder, major depressive disorder,
panic disorder and
phobias between husbands and wives in two population-based samples. We
further evaluated
whether marital resemblance occurs primarily within or across psychiatric
disorders and if
assortment for psychopathology is primary or secondary to assortment for
correlated variables.

Methods. A model for mate selection addressed whether the correlation
between mates for
psychiatric disorders arises from direct assortment (primary homogamy)
or through correlation
with other variables for which assortment occurs (secondary homogamy) or
through cross-variable
assortment. The model accounted for within-person co-morbidity as well
as across-spouse data.

Results. Findings suggested that a moderate degree of assortment
exists both within and across
psychiatric diagnoses. Only a small amount of the observed marital resemblance
for mental illness
could be explained by assortment for correlated variables such as age,
religious attendance and
education. Similar results were obtained for the two samples separately
and confirmed in their joint
analysis, revealing that the co-morbidity and assortment findings, except
for the marital correlation
for age, religious attendance and education, replicate across samples.

Conclusions. Significant but moderate primary assortment exists
for psychiatric disorders. The bias
in twin studies that have ignored the small amount of assortment is negligible.
Partners in life and in death: the suicide pact in
England and Wales 1988–1992
Authors: BROWN MARTIN , BARRACLOUGH BRIAN
Published: July 2002

Background. We describe the epidemiology of suicide pacts in England and Wales and assess the
health, circumstances and motivation of those who died in pacts; the first such account for 35 years.

Methods. We have analysed the death certificates, coroners' records and medical notes of all people
who died in suicide pacts in England and Wales between 1 January 1988 and 31 December 1992.

Results. The 124 suicides in 62 pacts accounted for 0·6% of all suicides giving a rate of 0·6 per
million. The average age was 56 years. Poisoning by car exhaust or medicines caused 95% of deaths,
both members of each pair using the same method. Forty-eight pacts were between married couples,
five between blood relatives. Mental disorder was present in half and medical illness in one-third.
Motives were avoiding loss of a partner from ill-health in 26 pacts, euthanasia in nine, thwarted love
in four.

Conclusions. The findings are similar to those of 35 years ago except the incidence of pacts is less.
Improved management of illness might avoid some pacts especially when partners in an enduring,
affectionate relationship, with few social ties, are both ill.
Assessing the capacity of people with intellectual
disabilities to be witnesses in court
Authors: GUDJONSSON G. H. , MURPHY G. H. , CLARE I. C. H.
Published: July 2002

Background. People with intellectual disabilities who have been victims or other witnesses of crime
have had limited access to the criminal justice system, often on the basis of assumptions about their
incapacity to be interviewed by the police and to give evidence in court. The aim of this study was
to assess their capacity to be witnesses in court.

Methods. Forty-nine men and women with intellectual disabilities, all of whom were potential
witnesses of ill-treatment, were assessed in order to provide advice, initially to the police, about their
capacity to be interviewed for judicial purposes. The assessments included evaluations of each
person's intellectual ability, memory, acquiescence, suggestibility, and their ability to explain
concepts relating to the oath.

Results. Only 37 (76%) were able to complete the assessments. Most of those with a Full Scale IQ
score of [ges ] 60 had a basic understanding of the oath, compared with only a third of those with IQ
scores between 50 and 59, and none of those with IQ scores < 50. Nevertheless, some of the people
who were unable to demonstrate an understanding of the oath did understand the words ‘truth’ and
‘lie’, especially when asked about these concepts in relation to concrete examples.

Conclusions. While intellectual ability appears to be the best overall predictor of the capacity of
people with intellectual disabilities to act as witnesses, confining witnesses to those who could
explain the meaning of the oath would mean that a number of persons who might be interviewed
by the police and subsequently appear in court could be excluded from the judicial process.
What contributes to depression in Parkinson's disease?
Authors: SCHRAG A. , JAHANSHAHI M. , QUINN N. P.
Published: July 2002

Background. Depression is a common problem in patients with Parkinson's disease, but its
mechanism is poorly understood. It is thought that neurochemical changes contribute to its
occurrence, but it is unclear why some patients develop depression and others do not. Using a
community-based sample of patients with Parkinson's disease, we investigated the contributions of
impairment, disability and handicap to depression in Parkinson's disease.

Methods. Ninety-seven patients seen in a population-based study on the prevalence of Parkinson's
disease completed the Beck Depression Inventory (BDI). Clinical and historical information on
symptoms and complications of Parkinson's disease were obtained from the patients by a
neurologist. In addition, clinician and patient ratings of disability on the Schwab and England scale
were obtained and a quality of life questionnaire was completed.

Results. Moderate to severe depression (BDI [ges ] 18) was reported by 19·6% of the patients. Higher
depression scores were associated with advancing disease severity, recent self-reported deterioration,
higher akinesia scores, a mini-mental score of < 25 and occurrence of falls. Disability as rated by
the neurologist accounted for 34% of the variance of depression scores. Self-reported impairment
of cognitive function and the feeling of stigmatization accounted for > 50% of the variance of
depression scores.

Conclusions. Depression in patients with Parkinson's disease is associated with advancing disease
severity, recent disease deterioration and occurrence of falls. Regression analysis suggests that
depression in Parkinson's disease is more strongly influenced by the patients' perceptions of
handicap than by actual disability. The treatment of depression should therefore be targeted
independently of treatment of the motor symptoms of Parkinson's disease, and consider the
patients' own perception of their disease.
Executive function and attention deficit hyperactivity
disorder: stimulant medication and better executive
function performance in children
Authors: KEMPTON S. , VANCE A. , MARUFF P. , LUK E. , COSTIN J. , PANTELIS C.
Published: July 2002

Background. Executive function deficits have been reported repeatedly in children with Attention
Deficit Hyperactivity Disorder (ADHD). Stimulant medication has been shown to be effective in
improving cognitive performance on most executive function tasks, but neuropsychological tests of
executive function in this population have yielded inconsistent results. Methodological limitations
may explain these inconsistencies. This study aimed to measure executive function in medicated and
non-medicated children with ADHD by using a computerized battery, the Cambridge Neuropsychological
Test Automated Battery (CANTAB), which is sensitive to executive function deficits
in older patients with frontostriatal neurological impairments.

Methods. Executive function was assessed in 30 children with ADHD: 15 were stimulant medication
naïve and 15 were treated with stimulant medication. These two groups were compared to 15 age,
sex and IQ matched controls.

Results. The unmedicated children with ADHD displayed specific cognitive impairments on
executive function tasks of spatial short-term memory, spatial working memory, set-shifting ability
and planning ability. Impairments were also seen on spatial recognition memory and delayed
matching to sample, while pattern recognition memory remained intact. The medicated children
with ADHD were not impaired on any of the above executive function tasks except for deficits in
spatial recognition memory.

Conclusions. ADHD is associated with deficits in executive function. Stimulant medication is
associated with better executive function performance. Prospective follow-up studies are required
to examine these effects.
Rationality and public evidence: a reply to Richard Swinburne
Authors: PLANTINGA ALVIN
Published: July 2002

First, my thanks to Richard Swinburne for his probing and thoughtful review
of my book Warranted Christian Belief (WCB). His account of the book's mainline of
argument is accurate as far as it goes; it does contain an important lacuna, however.
The focus of the book is twofold; it is aimed in two directions. First, just as
Swinburne says, I argue that there are no plausible de iure objections to Christian
belief that are independent of de facto objections; any plausible objection to the
rationality of Christian belief, or to its warrant (the property that distinguishes
knowledge from mere true belief), or its justification, will either be obviously
mistaken or will (as with Freud, and Marx and a thousand others) presuppose one
or more de facto objections. This is intended as a contribution to apologetics; it is
important, because many or most objections to Christian belief are of just the sort
I attempt to discredit. (‘I don't know whether Christian belief is true or not – who
could know a thing like that? – but I do know that it is irrational, or unwarranted,
or not rationally justified, or…’.) Second (and this is the focus Swinburne fails to
mention), I proposed the extended A/C (Aquinas/Calvin) model as, from the
perspective of Christian belief, a plausible account of the way in which Christian
belief is, in fact, justified, rational and warranted. So the book is aimed in two
directions: first towards readers generally, whether Christian believers or not, and
second towards Christian believers.
Climacus the (multi-dimensional) humorist:
interpreting ‘An understanding with the reader’
Authors: VIPPERMAN KRISTY
Published: July 2002

‘An understanding with the reader’ which appears as an appendix to
Kierkegaard's Concluding Unscientific Postscript has puzzled readers by apparently
‘taking back’ everything that the pseudonymous author Climacus has said in the
text that precedes it. I agree with John Lippitt that this ‘revocation’ should be read
as a humorous statement; however, I disagree with Lippitt's assessment that the
tone of the revocation is essentially ‘non-urgent’ and
‘modest’. I propose that a
fuller picture of Climacus's character is needed to understand the spirit of the
revocation and its relationship to the rest of the text.
Explaining the Drug–Crime Link:
Theoretical, Policy and Research Issues
Authors: SEDDON TOBY
Published: July 2002

The belief that drug addiction is the motor behind much property crime
has been a key part of recent UK drug policy. Review of the literature
shows that the empirical evidence does not support this view. It also
demonstrates that the fundamental weakness of existing research is its
failure to address the question of causality properly, relying mainly on
uni-directional mechanistic ‘cause-and-effect’ models. It is suggested that
the drug–crime link needs to be conceived in the context of the interaction
and inter-relation of a range of factors operating at different levels
and as part of a set of complex processes. The implications for policy are
that a reliance on improving access to treatment is likely to be of limited
effectiveness in reducing drug-related crime and that an emphasis on
tackling social exclusion may be more fruitful. Future research needs to
explore further the notion of causality outlined in this paper. It must also
examine emerging patterns of polydrug use and look at minority ethnic
groups and women.
Language and negotiation of ethnic/racial identity among
Dominican Americans
Authors: Bailey Benjamin
Published: July 2002

The ethnolinguistic terms in which the children of
Dominican immigrants in Rhode Island think of themselves,
i.e. as “Spanish” or “Hispanic,”
are frequently at odds with the phenotype-based racial
terms “Black” or “African American,”
applied to them by others in the United States. Spanish
language is central to resisting such phenotype-racial
categorization, which denies Dominican Americans their
Hispanic ethnicity. Through discourse analysis of naturally
occurring peer interaction at a high school, this article
shows how a Dominican American who is phenotypically indistinguishable
from African Americans uses language, in both intra- and
inter-ethnic contexts, to negotiate identity and resist
ascription to totalizing phenotype-racial categories. In
using language to resist such hegemonic social categorization,
the Dominican second generation is contributing to the
transformation of existing social categories and the constitution
of new ones in the US.
Calculating speakers: Codeswitching in a rational choice
model
Authors: MYERS-SCOTTON CAROL , BOLONYAI AGNES
Published: July 2002

Although the methodologies for describing many
types of linguistic variation have been well developed,
satisfactory theoretical links between data and explanation
– especially links that include causal mechanisms
– remain lacking. This article argues, somewhat paradoxically,
that even though most choices reflect some societal pattern,
speakers make linguistic choices as individuals. That is,
choices ultimately lie with the individual and are rationally
based. Rational Choice Models (e.g. Elster 1979, 1989,
1997) provide explanatory mechanisms for the ways actors
in society select from alternative structures and available
options. The Rational Choice approach taken here is enhanced
by diverse theories of human action (e.g. Damasio 1996,
Klein 1998, Lessig 1995). Analysis of codeswitching examples
within a recasting of the Markedness Model (Myers-Scotton,
e.g. 1993, 1998) suggests how a rationally based model
offers better explanations for linguistic variation than
do other approaches.
Dissociation of brain ERP topographies for tonal and phonetic oddball tasks
Authors: Kayser Jürgen , Tenke Craig E. , Bruder Gerard E.
Published: July 2002

ERP topographies for 30 scalp electrodes were examined in 26 healthy right‐handed volunteers during oddball tasks (20% targets) using binaurally presented consonant‐vowel syllables or complex tones. Response hand was counterbalanced across participants. Both window averages and a principal components analysis (PCA) with Varimax rotation revealed task‐related (tonal/phonetic) hemispheric asymmetries for N2, early P3, and particularly for N2‐P3 amplitude. In the tonal task, N2 was maximal over right lateral‐temporal regions, and early P3 over right medial‐parietal regions. For the phonetic task, N2 was maximal over the left lateral‐parietal regions, and late P3/N3 over left medial‐parietal regions. A response‐related frontal negativity (N3) interacted with task‐related asymmetries in an unbalanced fashion. The distinct, asymmetric N2 and P3 topographies for tonal and phonetic tasks presumably reflect differential involvement of cortical structures in pitch (right frontotemporal) and phoneme (left parietotemporal) discrimination.
Concerning the automaticity of syntactic processing
Authors: Gunter Thomas C. , Friederici Angela D.
Published: July 2002

In a within‐subjects design, event‐related potentials were compared for two types of sentence‐final syntactic errors: Incorrect verb inflection and incorrect word category (phrase structure). In a grammatical judgment task, these errors triggered robust N400 and P600 components. To assess the degree of automaticity of the underlying linguistic processes, the N400 and P600 effects were measured in a task for which the participants judged whether a word in a sentence was printed in upper case. In this physical judgment task, the N400 and P600 following verb inflection errors were greatly attenuated or absent, whereas those elicited by word category violation were only slightly diminished in amplitude. The data suggest that word category information is processed more automatically than inflectional information. The P600 appears to reflect a relatively controlled language‐related process.
The limbic language/language axis theory of speech
Authors: Joseph R.
Published: July 2002

In a recent BBS target article, MacNeilage (1998) presents what he claims to be the only theory that can account for the evolution of language. However, major portions of his target article basically repeat and in many respects are identical to the theories of language evolution and development first proposed and detailed by the present commentator.
Chaotic dynamics and psychophysical parallelism
Authors: Gregson Robert A. M.
Published: July 2002

An impressive review of brain neurophysiology provides the basis for modelling the dynamics of transmission in neural circuits, using appropriate nonlinear mathematics. The coverage is unbalanced, however: the parallel dynamics at the level of behaviour and sensory-cognitive processes are sparsely addressed, so the final chapter fails to indicate the complexity and subtlety of relevant modern work.
More women (and men) that never evolved
Authors: Cornwell R. Elisabeth , Palmer Craig T. , Davis Hasker P.
Published: July 2002

We are not convinced by Gangestad & Simpson that differential mating strategies within each sex would be greater than such strategies between sexes. The target article does not provide actual evidence of human males who do not desire mating with multiple females, or evidence that the benefits for females of short-term matings with multiple males have ever outweighed the associated costs.
The frame/content theory of evolution of speech production
Authors: MacNeilage Peter F.
Published: July 2002

The species-specific organizational property of speech is a
continual mouth open-close alternation, the two phases of which are
subject to continual articulatory modulation. The cycle constitutes
the syllable, and the open and closed phases are segments –
vowels and consonants, respectively. The fact that segmental serial
ordering errors in normal adults obey syllable structure constraints
suggests that syllabic “frames” and segmental
“content” elements are separately controlled in the
speech production process. The frames may derive from cycles of
mandibular oscillation present in humans from babbling onset, which
are responsible for the open-close alternation. These communication-
related frames perhaps first evolved when the ingestion-related
cyclicities of mandibular oscillation (associated with mastication
[chewing] sucking and licking) took on communicative significance
as lipsmacks, tonguesmacks, and teeth chatters – displays that
are prominent in many nonhuman primates. The new role of Broca's
area and its surround in human vocal communication may have derived
from its evolutionary history as the main cortical center for the
control of ingestive processes. The frame and content components
of speech may have subsequently evolved separate realizations
within two general purpose primate motor control systems: (1) a
motivation-related medial “intrinsic” system, including
anterior cingulate cortex and the supplementary motor area, for
self-generated behavior, formerly responsible for ancestral
vocalization control and now also responsible for frames, and
(2) a lateral “extrinsic” system, including Broca's
area and surround, and Wernicke's area, specialized for response
to external input (and therefore the emergent vocal learning capacity)
and more responsible for content.
Learning by imitation: A hierarchical approach
Authors: Byrne Richard W. , Russon Anne E.
Published: July 2002

To explain social learning without invoking the cognitively
complex concept of imitation, many learning mechanisms have been
proposed. Borrowing an idea used routinely in cognitive psychology,
we argue that most of these alternatives can be subsumed under a
single process, priming, in which input increases the
activation of stored internal representations. Imitation itself has
generally been seen as a “special faculty.” This has
diverted much research towards the all-or-none question of whether
an animal can imitate, with disappointingly inconclusive results. In
the great apes, however, voluntary, learned behaviour is organized
hierarchically. This means that imitation can occur at
various levels, of which we single out two clearly distinct ones: the
“action level,” a rather detailed and linear specification
of sequential acts, and the “program level,” a broader
description of subroutine structure and the hierarchical layout of a
behavioural “program.” Program level imitation is a
high-level, constructive mechanism, adapted for the efficient
learning of complex skills and thus not evident in the simple
manipulations used to test for imitation in the laboratory. As
examples, we describe the food-preparation techniques of wild
mountain gorillas and the imitative behaviour of orangutans
undergoing “rehabilitation” to the wild. Representing and
manipulating relations between objects seems to be one basic building
block in their hierarchical programs. There is evidence that great
apes suffer from a stricter capacity limit than humans in the
hierarchical depth of planning. We re-interpret some chimpanzee
behaviour previously described as “emulation” and suggest
that all great apes may be able to imitate at the program level.
Action level imitation is seldom observed in great ape skill learning,
and may have a largely social role, even in humans.
We need statistical thinking, not statistical rituals
Authors: Gigerenzer Gerd
Published: July 2002

What Chow calls NHSTP is an inconsistent hybrid of Fisherian
and Neyman-Pearsonian ideas. In psychology it has been practiced like
ritualistic handwashing and sustained by wishful thinking about its
utility. Chow argues that NHSTP is an important tool for ruling out
chance as an explanation for data. I disagree. This ritual discourages
theory development by providing researchers with no incentive to
specify hypotheses.
Representations need self-organizing top-down expectations to fit a changing world
Authors: Grossberg Stephen
Published: July 2002

“Chorus embodies an attempt to find out how far a mostly
bottom-up approach to representation can be taken.” Models that
embody both bottom-up and top-down learning have stronger
computational properties and explain more data about representation
than feedforward models do.
Regular spaces versus computing with chaos
Authors: van Leeuwen Cees
Published: July 2002

The attempt to provide a faithful mapping from distal shape
space to proximal state space in terms of a higher order relationship
defined over proximal similarity space stumbles on the context
sensitivity of higher order relationships. Proportional analogy
problems using quadruples of figures illustrate that for a number of
interesting perceptual problems, the number of relevant dimensions
cannot be reduced.