bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrothermal wave instability of thermocapillary-driven

convection in a coplanar magnetic field
Authors: PRIEDE JĀNIS , GERBETH GUNTER
Published: July 2002

We study the linear stability of surface-tension-driven

unidirectional shear flow in an

unbounded electrically conducting liquid layer heated from the side and
subjected

to a uniform magnetic field in the plane of the layer. The threshold of
convective

instability with respect to oblique travelling waves is calculated depending
on the

strength and orientation of the magnetic field. For longitudinal waves
the critical

Marangoni number and the corresponding wavelength are found to increase
directly

with the induction of a sufficiently strong magnetic field. In general,
a coplanar

magnetic field causes stabilization of all disturbances except those aligned
with the

field, which are not influenced at all. With increase of

the magnetic field this effect

results in the alignment of the most unstable disturbance along

the magnetic flux lines.

The maximal stabilization is ensured by the magnetic field being imposed
spanwise to

the basic flow. The corresponding critical Marangoni number is found to
be almost

insensitive to the thermal properties of the bottom. The strength

of the magnetic field

necessary to attain the maximal stabilization for a thermally

well-conducting bottom is

considerably lower than that for an insulating bottom. The basic

return flow is found

to be linearly stable with respect to purely hydrodynamic disturbances.
This effect

determines the stability of the basic state with respect to transverse
hydrothermal

waves at Prandtl number Pr<Prc=0.018.

For such a small Pr no alignment of

the critical perturbation with a spanwise magnetic field is possible,

and the critical

Marangoni number can be increased almost directly with the strength of
the magnetic

field without limit.
Collisional particle pressure measurements in

solid–liquid flows
Authors: ZENIT R. , HUNT M. L. , BRENNEN C. E.
Published: July 2002

Experiments were conducted to measure the collisional particle
pressure

in both

cocurrent and countercurrent flows of liquid–solid mixtures. The
collisional

particle

pressure, or granular pressure, is the additional pressure exerted on the
containing

walls of a particulate system due to the particle collisions. The present
experiments

involve both a liquid-fluidized bed using glass, plastic or steel spheres

and a vertical

gravity-driven flow using glass spheres. The particle pressure was measured
using a

high-frequency-response flush-mounted pressure transducer. Detailed recordings
were

made of many different particle collisions with the active face of

this transducer. The

solids fraction of the flowing mixtures was measured using an impedance
volume

fraction meter. Results show that the magnitude of the measured particle
pressure

increases from low concentrations (<10% solid volume fraction), reaches
a maximum

for intermediate values of solid fraction (30–40%), and decreases

again for more

concentrated mixtures (>40%). The measured collisional particle pressure

appears to

scale with the particle dynamic pressure based on the particle density
and terminal

velocity. Results were obtained and compared for a range of particle sizes,

as well as for two different test section diameters.

In addition, a detailed analysis of the collisions was performed that
included

the probability density functions for the collision duration and collision
impulse.

Two distinct contributions to the collisional particle pressure were identified:
one

contribution from direct contact of particles with the pressure transducer,
and the

second one resulting from particle collisions in the bulk that are

transmitted through the liquid to the pressure transducer.
Characteristics of endwall and sidewall boundary
layers in a rotating cylinder with a differentially rotating endwall
Authors: LOPEZ J. M.
Published: July 2002

The flow in a rotating cylinder driven by the differential rotation
of its top endwall
is studied by numerically solving the time-dependent axisymmetric Navier–Stokes

equations. When the differential rotation is small, the flow is well described
in
terms of similarity solutions of individual rotating disks of infinite
radius. For larger
differential rotations, whether the top is co-rotating or counter-rotating
results in
qualitatively distinct behaviour. For counter-rotation, the boundary layer
on the top
endwall separates, forming a free shear layer and this results in a global
coupling
between the boundary layer flows on the various walls and a global departure
from
the similarity flows. At large Reynolds numbers, this shear layer becomes
unstable.
For a co-rotating top, there is a qualitative change in the flow depending
on whether
the top rotates faster or slower than the rest of the cylinder. When the
top rotates
faster, so does the bulk of the interior fluid, and the sidewall boundary
layer region
where the fluid adjusts to the slower rotation rate of the cylinder is
centrifugally
unstable. The secondary induced meridional flow is also potentially unstable
in this
region. This is manifested by the inflectional radial profiles of the vertical
velocity
and azimuthal vorticity in this region. At large Reynolds numbers, the
instability of
the sidewall layer results in roll waves propagating downwards.
Fine-scale structure of thin vortical layers
Authors: ISHIHARA TAKASHI , KANEDA YUKIO
Published: July 2002

A class of exact solutions of the Navier–Stokes equations

is derived. Each of them
represents the velocity field v=U+u of a
thin vortical layer (a planar jet) under
a uniform strain velocity field U in three-dimensional infinite
space, and provides a
simple flow model in which nonlinear coupling between small eddies plays
a key role in
small-scale vortex dynamics. The small-scale structure of the velocity
field is studied
by numerically analysing the Fourier spectrum of u. It is shown
that the Fourier
spectrum of u falls off exponentially with wavenumber k

for large k. The Taylor
expansion in powers of the coordinate (say y) in the direction
perpendicular to the
vortical layer suggests that the solution may be well approximated by a
function with
certain poles in the complex y-plane. The Fourier spectrum based
on the singularities
is in good agreement with that obtained numerically, where the exponential
decay
rate is given by the distance of the poles from the real axis of y.
An experimental study of the motion of concentrated suspensions in
two-dimensional
channel flow. Part 1. Monodisperse systems
Authors: LYON M. K. , LEAL L. G.
Published: July 2002

A modified laser-Doppler velocimetry method is utilized to measure
fully developed
particle velocity and concentration profiles, as well as the mean-square
amplitudes of
velocity fluctuations (i.e. one component of the so-called particle temperature),
for
concentrated monodisperse suspensions across the narrow gap of a rectangular

channel. A stable index-of-refraction match of the suspending and particulate
phases
in conjunction with short-focal-length focusing optics has enabled data
acquisition up
to particle volume fractions of 0.50. In general, the particle concentration
distributions
possess a maximum near the channel centreline and a minimum at the channel
walls.
Coupled to these concentration distributions were blunted velocity profiles,
and
particle velocity fluctuation distributions that had a sharp maximum at
gap positions
approximately 80% of the way from the channel axis towards the walls. The
particle
velocity distributions were consistent with the absence of slip between
particles and the
suspending fluid.

The experimental data were compared with theoretical predictions from
the diffusive
flux model (Leighton & Acrivos 1987; Phillips et al. 1992),

a model due to Mills & Snabre (1995), and the suspensions balance model

(McTigue & Jenkins 1992; Nott & Brady 1994). The influence of
bulk particle concentration, suspension volumetric flow
rate, and ratio of channel gap width to particle diameter on the fully
developed profiles
was qualitatively consistent with the theoretical predictions from all
three models. For
the diffusive flux and suspension balance models, we used both literature
values for
model parameters, and values obtained from a best fit to our entire set
of experimental
data. Overall, the Mills & Snabre and suspension balance models were
found to
provide a better quantitative fit to the experimental data than the diffusive
flux model.
The Minimalist Program
Authors: ZWART JAN-WOUTER
Published: July 2002

Noam Chomsky,The Minimalist Program.
(Current Studies in Linguistics 28.) Cambridge, MA: MIT Press,
1995. Pp. 420.

The Minimalist Program, by Noam Chomsky, is a collection of
four articles,
‘The Theory of Principles and Parameters’ (written with Howard
Lasnik,
13–127), ‘Some notes on Economy of Derivation and representation’

(129–166), ‘A Minimalist Program for linguistic theory’
(167–217), and
‘Categories and transformations’ (219–394). The first
three articles have
appeared elsewhere, and are reprinted here with minor revisions. The fourth

was circulated in manuscript form earlier in 1995 and is commonly referred

to as ‘Chapter four’. The volume opens with an
‘Introduction’ (1–11) and
closes with a general bibliography and an index (395–420).

The work collected here is based on material presented by Chomsky, and

discussed by participating students, faculty, and visitors, in Chomsky's
fall
term lecture-seminars at MIT in the period of 1986 through 1994.
For those who have ever wanted to attend these class lectures, but were
never in the
position to, this is a must read. The MIT Press is to be commended for

having made this collection available in such an exemplary inexpensive
volume.
Steady magnetoacoustic waves and decay of solitonic structures in a finite-beta plasma
Authors: BAKHOLDIN I. , IL'ICHEV A. , ZHARKOV A.
Published: July 2002

The solitonic, periodic and quasiperiodic solutions that obey the full system

of transport equations describing one-dimensional motion of a isotropic collisionless

quasineutral plasma in a magnetic field are treated. The domains of physical parameters

of such a plasma are determined for fast and slow magnetoacoustic

branches, where solitary waves and generalized solitary waves exist. In the parameter

domain where solitary waves are replaced by non-local generalized solitary

waves, the localized disturbances are subject to decay, which has qualitatively different

mechanisms for fast and slow magnetoacoustic waves. The specific feature of

the decay process for fast waves is found to be characterized by a decrease of energy

of the disturbance due to quasistationary radiation of a resonant periodic wave

of the same nature. Analogous disturbances, having the form of a slow magnetoacoustic

solitary wave core, practically do not radiate resonant Alfvénic modes, but

rapidly lose energy as a result of continuous shedding of a slow-wave component.

Various types of shock waves are also considered. Their structure is formed by existing

solitonic configurations – solitary and generalized solitary waves. Possibilities

of observations of solitary waves and their decay in a real plasma are discussed.
Solitary-wave decay in a cold plasma
Authors: BAKHOLDIN IGOR' , IL'ICHEV ANDREJ
Published: July 2002

A numerical investigation of the evolution of localized disturbances
in the form
of solitary waves is performed for the full system of equations describing
planar
waves in a cold collisionless quasineutral plasma. It is shown that, for
a wide
range of angles of inclination of the magnetic field vector to the direction
of
wave propagation, such a kind of initial disturbance never results in a
wave
propagating steadily, but leads to decay due to radiation of periodic waves.

These results confirm the recent theoretical conclusion of Il'ichev
[J. Plasma
Phys.55, 181–194 (1996)] about the non-existence

of solitary waves in a cold
plasma for the range of angles of inclination in question.
Settlement, post-settlement mortality and growth of the damselfish Chromis fumea (Pisces: Pomacentridae) on two artificial reefs in New Caledonia (south-west Pacific ocean)
Authors: Wantiez Laurent , Thollot Pierre
Published: July 2002

Density and size of Chromis fumea (Pisces: Pomacentridae) were regularly monitored during 13 months (from August 1996 to August 1997), on two artificial reefs in New Caledonia (south-west Pacific ocean): a ship-wreck (CT2) just after scuttling, and an assemblage of iron boxes (Caissons) sunk more than 50 years ago. The settlement of C. fumea was first observed 20 August 1996 and lasted 20 days. At the beginning the recruits were 1 cm size-class fish and at the end 2 cm size-class. This major settlement phase was again observed one year later (September 1997). A second minor settlement phase occurred in December 1996 on CT2. Significant immigration of adults was also observed between November 1996 (6 cm) and April 1997 (7 cm), indicating that this species is capable of medium range migration (>50 m). Population size decreased by 87·8% between the settlement of juveniles and the first immigration phase of adults. The final density of the 1996 cohort was 10·5% of the initial input of recruits on CT2 and 19·3% on Caissons. Initial density of recruits was 3·4 times higher on CT2 than on Caissons, whereas density of juveniles was similar at the end of the survey, indicating that post-settlement mortality was greater on CT2. Chromis fumea von Bertalanffy growth models were similar on CT2 and Caissons. This short-lived species is characterized by an initial rapid growth phase (K>3·36 y−1), with the fish reaching 68·5% of L∞ in three months, and a second slower growth phase (1 cm in ten months).
Linking estuarine nematodes to their suspected food. A case study from the Westerschelde Estuary (south-west Netherlands)
Authors: Moens Tom , Van Gansbeke Dirk , Vincx Magda
Published: July 2002

The present study investigates correlations between abundances of nematodes (at the genus level) and benthic microalgae on an intertidal mudflat in the Westerschelde Estuary (south-west Netherlands), using both multi- and univariate methods. Two sample series, covering surface areas of 10 cm2 (meioscale) and 1.25 cm2 (microscale) per sample were analysed. Trophic type analysis indicated that an average of 31% of the nematode community were candidate grazers of microalgae. Multivariate data analysis indicated that only a limited part of the variation in the nematode data could be explained in relation to pigments. Total nematodes did not show any correlation with the pigment data. On the meioscale, the genera Tripyloides and Calyptronema correlated negatively with chlorophyll concentration (chl-a and chl-c, respectively), while Prochromadorella correlated positively with the ratio of fucoxanthin to chl-a, a ratio which at the present sampling site can be considered to be a measure of the proportion of diatoms in the total microalgal standing stock. On the microscale, up to ten genera, comprising 76% of total nematode numbers, were correlated with pigments. A majority (74%) correlated specifically with the ratio of fucoxanthin to chl-a, while much fewer nematodes showed a direct correlation to pigment concentrations. Whereas many of these correlations could be explained in terms of direct trophic links, several others probably represented indirect relationships, trophic or other. Food densities may be less important structuring factors of nematode communities on tidal flats than relative abundances of particular food sources. It is suggested that nematodes actively migrate towards ‘optimal’ food patches, and that this dynamic aspect of nematode–microalgae correlations is best revealed at a spatial-scale small enough to allow a rapid response of nematodes to changes in adjacent patches. Apparently, the microscale used in the present study is more adequate for the study of such intricate interactions than the meioscale.
A new isopod species from the abyssal South Pacific ocean: Eugerda gigantea sp. nov. (Isopoda: Asellota: Desmosomatidae)
Authors: Park Ja-Yang
Published: July 2002

The new species Eugerda gigantea sp. nov. is described from the abyssal of the equatorial eastern South Pacific. For the genus Eugerda this is the first record from the South Pacific ocean, the other known species of the genus occur in the northern hemisphere or the equatorial Atlantic ocean.
Cosmologies, Truth Regimes, and the State in Southeast Asia
Authors: Day Tony , Reynolds Craig J.
Published: July 2002

It has been said that post-capitalist society is a ‘knowledge society.’ Certainly the revolution in information technology has made the issue of knowledge production controversial and topical. Southeast Asian societies, while they may not be post-capitalist, have a thirst for knowledge as their capitalist classes become more complex and search for solutions to their problems. These problems of the middle classes are not only commercial, professional, and political, but also personal, psychological, and familial. Cable TV, satellite services, CD-ROM, the Internet, and so forth, sensitize us to the production, formatting, transmission, and reception of knowledge not only in our own age but also in the past. Since early times the state has been both shaped by and involved itself in the processes of knowledge formation and dissemination.
James 4.5 Reconsidered
Authors: CARPENTER CRAIG B.
Published: July 2002

Jas 4.5 poses several exegetical difficulties. Particularly elusive has been identifying the ‘scripture’ to which James refers. This article suggests a fresh translation and reading of vv. 5–6. It is argued that vv. 5b–6a constitute an indirect discourse construction. This is grammatically possible and best takes into account the paraenetic context of chapter 4. Further, the two main sections of these verses correspond functionally to the two cola of the quotation from Prov 3.34 in v. 6. Hence, vv. 5b–6a serve as an introductory gloss to the proverb designed to advance James's paraenetic aims.
An analysis of the safety of the single dose, two drug regimens used in programmes to eliminate lymphatic filariasis
Authors: HORTON J. , WITT C. , OTTESEN E.A. , LAZDINS J.K. , ADDISS D.G. , AWADZI K. , BEACH M.J. , BELIZARIO V.Y. , DUNYO S.K. , ESPINEL M. , GYAPONG J.O. , HOSSAIN M. , ISMAIL M.M. , JAYAKODY R.L. , LAMMIE P.J. , MAKUNDE W. , RICHARD-LENOBLE D. , SELVE B. , SHENOY R.K. , SIMONSEN P.E. , WAMAE C.N. , WEERASOORIYA M.V.
Published: July 2002

This review of the safety of the co-administration regimens to be used in programmes to eliminate lymphatic filariasis (albendazole+ivermectin or albendazole+diethylcarbamazine [DEC]) is based on 17 studies conducted in Sri Lanka, India, Haiti, Ghana, Tanzania, Kenya, Ecuador, the Philippines, Gabon, Papua New Guinea, and Bangladesh. The total data set comprises 90635 subject exposures and includes individuals of all ages and both genders. Results are presented for hospital-based studies, laboratory studies, active surveillance of microfilaria-positive and microfilaria-negative individuals, and passive monitoring in both community-based studies and mass treatment programmes of individuals treated with albendazole (n=1538), ivermectin (9822), DEC (576), albendazole+ivermectin (7470), albendazole+DEC (69020), or placebo (1144). The most rigorous monitoring, which includes haematological and biochemical laboratory parameters pre- and post-treatment, provides no evidence that consistent changes are induced by any treatment; the majority of abnormalities appear to be sporadic, and the addition of albendazole to either ivermectin or DEC does not increase the frequency of abnormalities. Both DEC and ivermectin show, as expected, an adverse event profile compatible with the destruction of microfilariae. The addition of albendazole to either single-drug treatment regimen does not appear to increase the frequency or intensity of events seen with these microfilaricidal drugs when used alone. Direct observations indicated that the level of adverse events, both frequency and intensity, was correlated with the level of microfilaraemia. In non microfilaraemic individuals, who form 80–90% of the ‘at risk’ populations to be treated in most national public health programmes to eliminate lymphatic filariasis (LF), the event profile with the compounds alone or in combination does not differ significantly from that of placebo. Data on the use of ivermectin+albendazole in areas either of double infection (onchocerciasis and LF), or of loiais (with or without concurrent LF) are still inadequate and further studies are needed. Additional data are also recommended for populations infected with Brugia malayi, since most data thus far derive from populations infected with Wuchereria bancrofti.
Evidence for selection for the tyrosine-86 allele of the

pfmdr 1 gene of Plasmodium falciparum by

chloroquine and amodiaquine
Authors: DURAISINGH M. T. , DRAKELEY C. J. , MULLER O. , BAILEY R. , SNOUNOU G. , TARGETT G. A. T. , GREENWOOD B. M. , WARHURST D. C.
Published: July 2002

The 4-aminoquinolines chloroquine (CQ) and amodiaquine (AM)

were used to treat Gambian children with uncomplicated falciparum malaria

in a randomized drug trial. Blood samples were taken immediately before

treatment (day 0), and at day 7 and day 28 after treatment. Samples

from those parasitologically positive at day 7 following treatment

(‘early positives’) and those positive at day 28 but negative

at day 7 (‘late positives’) have been studied by PCR followed

by restriction enzyme digestion to determine the allelic status of the

pfmdr 1 locus at the codon-86 position (asparagine

or tyrosine), previously associated with resistance to CQ. A

significantly higher prevalence of the tyr-86 allele was observed

in samples taken immediately before treatment (day 0) in the early

positives group when compared with the late positives

group. This suggests the tyr-86 allele contributes to drug resistance

in the early positives group. This association remained

significant for both CQ and AM groups, implying a common genetic basis

of resistance. Predominance of the allele at day

7 is consistent with a strong selection in the first week following

treatment. In the late positives group, a significantly

higher prevalence of the tyr-86 allele was observed in the samples at

day 28 when compared with those at day 0, suggestive

of selection during the period day 7 to day 28. Differences were observed

in the extent of this selection in the CQ and AM

groups. The samples were genotyped at 3 unlinked polymorphic loci. These

analyses suggested that most parasites

observed at day 7 were probably recrudescences whereas most of those at

day 28 were reinfections.
Molecular and functional characterization and tissue
localization of 2 glucose transporter homologues (TGTP1
and TGTP2) from the tapeworm Taenia solium
Authors: RODRÍGUEZ-CONTRERAS D. , SKELLY P. J. , LANDA A. , SHOEMAKER C. B. , LACLETTE J. P.
Published: July 2002

Tapeworms absorb and consume large quantities of glucose through
their syncytial tegument, storing the excess as
glycogen. Although some studies on the metabolism of glucose in several
tapeworms are available, the proteins that mediate
its uptake and distribution in their tissue have not been identified. We
describe the isolation and characterization of cDNA
clones encoding 2 facilitated diffusion glucose transporters (TGTP1 and
TGTP2) from Taenia solium, the causal agent
of human and porcine cysticercosis. Radio-isotope labelled hexose uptake
mediated by TGTP1 expressed in Xenopus
oocytes is inhibited by the natural stereoisomers d-glucose and
d-mannose but not by l-glucose. Transport by TGTP1
is sensitive to classical inhibitors of facilitated diffusion such as phloretin
and cytochalasin B, and insensitive to ouabain.
TGTP2 did not function in Xenopus oocytes. Localization studies
using specific anti-TGTP1 and anti-TGTP2 antibodies
show that TGTP1 is abundant in a number of structures underlying the tegument
in adult parasites and larvae, whereas
TGTP2 appears to be localized only on the tegumentary surface of the larvae
and is not detected in adults.
Association of cg2 and pfmdr1 genotype with chloroquine
resistance in field samples of Plasmodium falciparum from
Nigeria
Authors: ADAGU I. S. , WARHURST D. C.
Published: July 2002

This study examines polymorphisms in 2 genes (pfmdr1 and cg2), which have been associated with resistance to
chloroquine in Plasmodium falciparum, to determine their value as predictors of resistance status. Among field samples
from children in Zaria, northern Nigeria, the Tyr-86 polymorphism in pfmdr1 and Ala-281 and the Dd2κ repeat of cg2,
were significantly associated. In 8 samples classified resistant by the micro-in vitro test, or, where this failed, by in vivo
trial, 7 showed the cg2 Dd2 type κ repeat, and 6 of these had both the Ala-281 allele and the pfmdr1 Tyr-86 allele. In 26
chloroquine-sensitive samples, none had this combination of 3 polymorphisms (P = 0·00002). This indicates 75%
sensitivity and 100% specificity in detection of resistance and shows a positive predictive value for resistant infections of
100%. The negative predictive value, because of sensitivity less than 100%, would depend on the prevalence of resistance.
Where prevalence of resistance is approx. 21% as in Zaria, the negative predictive value would be 94%, while in Gabon,
with a prevalence of ca 73% it would be 60%. The use of (cg2: Ala-281, Dd2κ. pfmdr1: Tyr-86) genotype detection as
a predictive epidemiological tool to examine the distribution of chloroquine-resistance in parts of Africa is therefore
possible. The sensitivity of detection of resistant strains still requires improvement.
Temperament and the structure of personality
disorder symptoms
Authors: MULDER ROGER T. , JOYCE PETER R.
Published: July 2002

This paper attempts to construct a simplified system for the classification of personality
disorders, and relates this system to normally distributed human personality characteristics. One
hundred and forty-eight subjects with a variety of psychiatric diagnoses were evaluated using the
SCID-II structured clinical interview for personality disorders. A four-factor solution of personality
disorder symptoms was obtained and we labelled these factors ‘the four As’ : antisocial, asocial,
asthenic and anankastic. The factors related to the four temperament dimensions of the
Tridimensional Personality Questionnaire (TPQ), but less closely to Eysenck Personality
Questionnaire (EPQ) dimensions. The four factors were similar to those identified in a number of
studies using a variety of assessment methods and this lends some credibility to our findings. It
suggests that a more parsimonious set of trait descriptors could be used to provide simpler, less
overlapping categories that retain links with current clinical practice. In addition, these factors can
be seen as extremes of normally distributed behaviours obtained using the TPQ questionnaire.
Right lower prefronto-parietal cortical dysfunction in
akinetic catatonia: a combined study of
neuropsychology and regional cerebral blood flow
Authors: NORTHOFF G. , STEINKE R. , NAGEL D. , CZERWENKA C. , GROSSER O. , DANOS P. , GENZ A. , KRAUSE R. , BÖKER H. , OTTO H. J. , BOGERTS B.
Published: July 2002

Background. Catatonia is a psychomotor syndrome that can be characterized by behavioural,
affective and motor abnormalities. In order to reveal further underlying pathophysiological
mechanisms of psychomotor disturbances in catatonia we investigated neuropsychological function
and regional cerebral perfusion (r-CBF) in a combined study.

Methods. Ten catatonic patients were investigated with Tc-99mECD brain SPECT and compared
with 10 psychiatric (similar age, sex, medication and underlying psychiatric diagnosis but without
catatonic syndrome) and 20 healthy controls. Neuropsychological measures included tests for
general intelligence, attention, executive functions and right parietal visual–spatial abilities.
Correlational analyses were performed between neuropsychological measures, catatonic symptoms
and r-CBF.

Results. Catatonic patients showed a significant decrease of r-CBF in right lower and middle
prefrontal and parietal cortex compared with psychiatric and healthy controls as well as
significantly poorer performance in visual–spatial abilities associated with right parietal function.
Correlational analysis revealed significant correlations between visual–spatial abilities and right
parietal r-CBF only in psychiatric and healthy controls but not in catatonic patients. In contrast,
attentional measures correlated significantly with motor symptoms, visual–spatial abilities and right
parietal r-CBF in catatonia only but not in psychiatric or in healthy controls.

Conclusion. Findings are preliminary but suggest right lower prefronto-parietal cortical dysfunction
in catatonia, which may be closely related to psychomotor disturbances.
Determinants of neurological dysfunction in first episode schizophrenia
Authors: BROWNE S. , CLARKE M. , GERVIN M. , LANE A. , WADDINGTON J. L. , LARKIN C. , O'CALLAGHAN E.
Published: July 2002

Background. Although it is well recognized that individuals with schizophrenia display evidence of
subtle neurological impairment, its aetiopathological and clinical significance continues to be
unclear.

Methods. Patients presenting with a first episode of schizophrenia or schizophreniform psychosis
(DSM-IV criteria) were examined using two previously validated neurological examinations. The
majority (N = 35) were examined prior to their ‘first ever’ dose of neuroleptic while the remaining
patients (N = 21) had been medicated for less than one month. The manner in which neurological
functioning is influenced by symptomatology and handedness was ascertained.

Results. The majority of patients who were examined neuroleptic-naive displayed evidence of
neurodysfunction. A combination of relative hand preference and symptomatology explained a
significant proportion of the variance in neurological functioning. Mixed handedness among adults
at the time of first presentation with schizophrenia was associated with more severe neurological
impairment and a history of poorer scholastic attainment and pre-morbid social adjustment.

Conclusions. Neurological soft signs are an intrinsic part of schizophrenia rather than a direct
consequence of treatment. Early developmental processes are associated with the level of
subsequent neurological impairment in first episode schizophrenia. However, symptomatology
appears to have an influence on the apparent severity of neurological impairment.
Social Policy Digest NUMBER ONE HUNDRED AND TEN August to October 1998
Authors: BENNETT FRAN
Published: July 2002

Contents

1 Social security and income maintenance

2 Health care

3 Education

4 Housing and environment

5 Personal social services

6 Law and the treatment of the offender

7 Unemployment and the labour market

8 Race relations

9 The voluntary sector

10 Local government

11 Gender

12 Demography
Merging auditory and visual phonetic information: A critical test for feedback?
Authors: Brancazio Lawrence , Fowler Carol A.
Published: July 2002

The present description of the Merge model addresses only auditory, not audiovisual, speech perception. However, recent findings in the audiovisual domain are relevant to the model. We outline a test that we are conducting of the adequacy of Merge, modified to accept visual information about articulation.
Feeding forward versus feeding backward
Authors: Gardner R. Allen
Published: July 2002

The Domjan et al. target article is a valuable summary of a vital field of conditioning and learning. It lists, thumbnails, and organizes classical and recent findings into a useful and familiar structure. Perhaps it is time to consider modern developments in ethology, experimental psychology, and computer science that supersede the traditional structure.
Schema theory: Very promising
Authors: Grunewald Alexander
Published: July 2002

A direct equivalence between neural function and neural structure does not provide a fruitful approach to understanding brain functioning. Arbib et al. describe a new and powerful approach to circumvent this problem, which they call schema theory. However, in examples they fall prey to the tradition of finding such equivalences, not doing schema theory justice.
Objectivity, intentionality, and levels of explanation
Authors: Müller Ulrich , Carpendale Jeremy I. M.
Published: July 2002

Notwithstanding many similarities between Thelen et al.'s and Piaget's accounts of the A-not-B error, we argue that, in contrast to Piaget, they do not explicitly address the issue of objectivity. We suggest that this omission is partly due to the fact that Thelen et al. and Piaget's accounts are pitched at different levels of explanation.
If the magical number is 4, how does one account for operations within working memory?
Authors: Pascual-Leone Juan
Published: July 2002

Cowan fails to obtain a magical number of 7 because his analysis is faulty. This is revealed by an alternative analysis of Cowan's own tasks. The analysis assumes a number 7 for adults, and neoPiagetian mental- capacity values for children. Data patterns and proportions of success (reported in Cowan's Figs. 2 and 3) are thus quantitatively explained in detail for the first time.
Plasticity: Implications for opioid and other pharmacological interventions in specific pain states
Authors: Dickenson Anthony H.
Published: July 2002

The spinal mechanisms of action of opioids under normal
conditions are reasonably well understood. The spinal effects of
opioids can be enhanced or reduced depending on pathology and
activity in other segmental and nonsegmental pathways. This
plasticity will be considered in relation to the control of different
pain states using opioids. The complex and contradictory findings
on the supraspinal actions of opioids are explicable in terms of
heterogeneous descending pathways to different spinal targets
using multiple transmitters and receptors – therefore opioids
can both increase and decrease activity in descending pathways. These
pathways could exhibit considerable plasticity. There is increasing
evidence that delta opioid receptor agonists have the potential to
replace morphine as major analgesics with reduced side-effect
profiles. The concept of preemptive analgesia, based on preventing
the induction of some of the negative plastic influences on opioid
controls and the detrimental effects of pain, is sound, but
experimental verification in the clinical setting is difficult. For
example, a delayed compensatory upregulation of inhibitory
systems, particularly in inflammation, may counter persistent
painful inputs. Combination therapy with opioids may be beneficial
in many pain states where either negative influences are blocked
or inhibitory controls are enhanced. Finally, developmental aspects
of these systems are discussed in connection with the treatment
of pain in young children, where inhibitory systems in the spinal
cord are immature.
In defense of learning by selection: Neurobiological and behavioral evidence revisited
Authors: Dehaene-Lambertz G. , Dehaene Stanislas
Published: July 2002

Quartz & Sejnowski's (Q&S's) constructivist
manifesto promotes a return to an extreme form of empiricism. In
defense of learning by selection, we argue that at the neurobiological
level all the data presented by Q&S in support of their
constructive model are in fact compatible with a model comprising
multiple overlapping stages of synaptic overproduction and selection.
We briefly review developmental studies at the behavioral level in
humans providing evidence in favor of a selectionist view of
development.
Can mere phonemes be components of Millikan's substance concepts?
Authors: Scharer Niko
Published: July 2002

In presenting her attractive theory of concepts, Millikan
makes an unwarranted assumption about the role of language in concept
acquisition. The phoneme string, rather than the “word”
as a semantic entity, may suffice to play the crucial role in the
acquisition of substance concepts. Hence Millikan may underestimate
the degree of similarity between language and other media of
perception.
Identifying, reidentifying, and misidentifying
Authors: Saidel Eric
Published: July 2002

Millikan (1998a) relies on the ability an organism may have to reidentify external objects. It is difficult to develop an account of how this might occur because the organism could make a mistake in the tokening of a concept; it could misidentify the external object. To sustain her nondescriptivism, Millikan's account of reidentification must make the link between concept and object arbitrary. However, to make mistakes possible, there must be a norm for the production of concepts. These two requirements seem to leave no room for a middle ground.
How to compare color sensations in different brains
Authors: Backhaus Werner
Published: July 2002

The qualitative and quantitative properties of color sensations and neuronal color coding are discussed in relation to physiological color exchanges and their evolutionary constraints. Based on the identity mind/matter thesis, additional physical measurements on color sensations are described that will allow us, at least in principle, to compare the qualitative properties of color sensations in different brains.
The underrated role of the “move system” in determining saccade latency
Authors: Dorris Michael C. , Munoz Douglas P.
Published: July 2002

The Findlay & Walker target article emphasizes the role of the target-nonspecific “fixate” system while downplaying the role of the target-specific “move” system in determining saccade latency. We agree that disengagement of the fixate system is responsible for the target-nonspecific latency reduction associated with the gap effect. However, high target predictability and extensive training at a target location can also result in latency reductions, the culmination of this being express saccades. The target-specificity associated with the latter forms of latency reduction implicate a mechanism involving the move system. Recently discovered neurophysiological correlates underlying these behavioural phenomena reside in the superior colliculus.
Neurophysiology indicates cognitive penetration of the visual system
Authors: Grunewald Alexander
Published: July 2002

Short-term memory, nonattentional task effects and
nonspatial extraretinal representations in the visual system
are signs of cognitive penetration. All of these have been found
physiologically, arguing against the cognitive impenetrability of
vision as a whole. Instead, parallel subcircuits in the brain, each
subserving a different competency including sensory and cognitive
(and in some cases motor) aspects, may have cognitively impenetrable
components.
We all are Rembrandt experts – or, How task dissociations in school learning effects support the discontinuity hypothesis
Authors: Kolinsky Régine , Morais José
Published: July 2002

We argue that cognitive penetration in non-early vision
extends beyond the special situations considered by Pylyshyn. Many
situations which do not involve difficult stimuli or require expert
skills nevertheless load on high-level cognitive processes. School
learning effects illustrate this point: they provide a way to observe
task dissociations which support the discontinuity hypothesis, but
they show that the scope of visual cognition in our visual experience
is often underestimated.
Implicit and explicit learning in a hybrid architecture of cognition
Authors: Lebiere Christian , Wallach Dieter
Published: July 2002

We present a theoretical account of implicit and explicit
learning in terms of act-r, an integrated architecture of human
cognition as a computational supplement to Dienes & Perner's
conceptual analysis of knowledge. Explicit learning is explained in
act-r by the acquisition of new symbolic knowledge, whereas
implicit learning amounts to statistically adjusting subsymbolic
quantities associated with that knowledge. We discuss the common
foundation of a set of models that are able to explain data gathered
in several signature paradigms of implicit learning.
The medial dorsal nucleus of the thalamus is not part of a hippocampal-thalamic memory system
Authors: Witter Menno P. , Van der Werf Ysbrand D.
Published: July 2002

Aggleton & Brown propose that familiarity-based
recognition depends on a perirhinal-medial dorsal thalamic system.
However, connections between these structures are sparse or absent. In
contrast, the perirhinal cortex is connected to midline/intralaminar
nuclei. In a human, a lesion in this thalamic domain, sparing the
medial dorsal nucleus, impaired familiarity-based recognition while
sparing recollective-based recognition. It is thus more likely that
the intralaminar/midline nuclei are involved in recognition.
Selecting is not abstracting
Authors: Ohlsson Stellan
Published: July 2002

Barsalou's hypothesis that mental representations are
constructed by selecting parts of percepts encounters the same
difficulties as other empiricist theories: They cannot explain
concepts for which instances do not share perceptible features
(e.g., furniture) or for which there are no relevant percepts
(e.g., the end of time). Barsalou's attempt to reduce
falsity to failed pattern matching is an elementary error, and the
generativity of his simulators cannot be attained without nonterminal
symbols. There is not now, and there never was, any reason to be
interested in empiricist theories of knowledge. Abstraction is a
fundamental aspect of human cognition.
Homoclinic bifurcations and the Floquet torus
Authors: MARTÍN J. C. , MORA L.
Published: July 2002

In this paper we show that a $C^r$ diffeomorphism having an invariant Floquet torus which is non-normally hyperbolic can be approximated, in the $C^{r-3}$ topology, by another one which exhibits a homoclinic tangency.
On normal numbers for continued fractions
Authors: KRAAIKAMP COR , NAKADA HITOSHI
Published: July 2002

In this paper we will show that any number normal with respect to the regular continued fraction (RCF) is also normal with respect to the continued fraction from below (BCF) and the nearest integer continued fraction (NICF). Furthermore, we will show that in case of the NICF a number is normal with respect to the RCF-expansion if and only if it is NICF-normal. This can be generalized to a larger class of semi-regular continued fraction expansions.
A property of vector fields without singularity in {\mathcal G}^1(M)
Authors: TOYOSHIBA HIROYOSHI
Published: July 2002

We prove the following property: if X in \mathcal G^1(M) has no singularity and x \in \Sigma(X), then \overline{\operatorname{orbit}(x)} \cap \overline{\operatorname{per}(X)} \not = \emptyset. In addition, if we assume \overline{\operatorname{per}_i(X)} \cap \overline{\operatorname{per}_j(X)} = \emptyset for i \not = j, then \overline{\operatorname{per}(X)} = \bigcup_{i=0}^{n-1} \overline{\operatorname{per}_i(X)} is a hyperbolic set. Moreover, we shall give a proof of the \Omega-stability conjecture for flows.
Commuting finite Blaschke products
Authors: ARTEAGA CARLOS
Published: July 2002

We consider the set of finite Blaschke products $F$ for which the fixed points on the circle $S^1$ are expanding and we prove that if $F'(x) \ne F'(y)$ for all different fixed points $x,y$ of $F$ on $S^1$, then $F$ commutes only with its own powers.
Current thinking in gerontology in Canada
Authors: KEATING NORAH , HOPPER COOK LINDA
Published: July 2002

The beginning of the new millennium seems a good time to reflect upon issues
in gerontology as many Western countries are experiencing population
ageing and the challenges it entails. In comparison to Europe's 14 per cent
average (Population Reference Bureau 2000), Canada is a relatively young
country with only about 12 per cent of the population over age 65 (Statistics
Canada 1999). Nonetheless, population ageing is a driving force in Canadian
gerontology. In this paper we discuss current thinking in gerontology in
Canada and how it reflects our approaches to research and development of
public policy. We begin with an overview of national policy and research
perspectives. We provide examples of research programmes addressing key
issues: population ageing and the welfare state, rethinking independence, and
quality of life issues from the Canadian perspective. Finally, we discuss the
values that provide the context for the development of approaches to funding
which affect the scope and direction of our research. Information sources
include national policy documents, recent publications by Canadian
gerontologists, and articles from the Canadian Journal on Aging 1998–2000.
Vicars of ‘Wannabe’: authenticity and the Spice Girls
Authors: LEACH ELIZABETH EVA
Published: July 2002

Popular notions of value in art – even popular definitions of art itself – are much indebted to the idealist narratives of
late romanticism and its maximalised form, elite modernism. Since artistic value is normally imputed to one side of a
dialectically related pair of oppositional terms, two principal strategies exist by which to ascribe value to the music
you love, find interesting, or want to study: either show how it merits the positive term of the valorising pair (if
necessary redefining the specific markers of that term), or attack the narrative underlying the binary itself. A typical
postmodernist strategy is to do both these things simultaneously, so as to collapse notions of value into a win-win
polysemy.
Reports and Surveys
Authors: Rudall B.H.
Published: July 2002

I. ADVANCED CYBORG (BIOLOGICAL ROBOT)

Whilst research continues to produce robots that mimic nature's creatures, scientists at the Northwestern University in Chicago, USA have developed a robot that

is controlled by the brain of a sea lamprey. This is therefore an example of a biological robot, perhaps the first of many that will be developed.
Artefacts in experimental economics: preference reversals and the Becker–DeGroot–Marschak mechanism
Authors: Guala Francesco
Published: July 2002

Controversies in economics often fizzle out unresolved. One reason is that, despite their professed empiricism, economists find it hard to agree on the interpretation of the relevant empirical evidence. In this paper I will present an example of a controversial issue first raised and then solved by recourse to laboratory experimentation. A major theme of this paper, then, concerns the methodological advantages of controlled experiments. The second theme is the nature of experimental artefacts and of the methods devised to detect them. Recent studies of experimental science have stressed that experimenters are often merely concerned about determining whether a certain phenomeonon exists or not, or whether, when, and where it can be produced, without necessarily engaging in proving or disproving any theoretical explanation of the phenomenon itself. In this paper I shall be concerned mainly with such a case, and focus on the example of preference reversals, a phenomenon whose existence was until quite recently denied by the majority of economists. Their favourite strategy consisted in trying to explain the phenomenon away as an artefact of the experimental techniques used to observe it. By controlled experimentation, as we shall see, such an interpretation has been discredited, and now preference reversals are generally accepted as real. The problem of distinguishing an artefact from a real phenomenon is related to methodological issues traditionally discussed by philosophers of science, such as the theory-ladenness of observation and Duhem's problem. Part of this paper is devoted to clarifying these two philosophical problems, and to arguing that only the latter is relevant to the case in hand. The solutions to Duhem's problem devised by economic experimentalists will be presented and discussed. I shall show that they belong in two broad categories: independent tests of new predictions derived from the competing hypotheses at stake, and ‘no-miracle arguments’ from different experimental techniques delivering converging results despite their being theoretically independent.