bluuebunny/crossref_metadata_2025 huggingface dataset:
Different psychopathological models and quantified EEG in schizophrenia
Authors: HARRIS A. W. F. , WILLIAMS L. , GORDON E. , BAHRAMALI H. , SLEWA-YOUNAN S.
Published: July 2002

Background. This study compared the ability of two different models of psychopathology in
schizophrenia to account for findings in the quantified electroencephalogram (qEEG) recorded
from midline sites in a group of 40 subjects with schizophrenia. The first model was based on the
positive and negative syndrome dichotomy, the second was a tripartite model that resembled
Liddle's syndromes of psychomotor poverty, disorganization and reality distortion (Liddle, 1987a).

Methods. A group of 40 subjects with predominantly chronic schizophrenia was assessed with the
Positive and Negative Syndrome Scale (PANSS) prior to the acquisition of their quantified
electroencephalogram. The relationship between EEG data and symptomatology was explored,
initially with the PANSS positive and negative subscales and then with a tripartite model derived
from a principal component analysis of the 14 positive and negative subscale items.

Results. The tripartite syndrome model showed a greater concordance with the qEEG of the
subjects than the dichotomous model. ‘Psychomotor poverty’ was significantly positively correlated
with both delta and beta power and ‘reality distortion’ was significantly positively correlated with
alpha-2 power. No significant correlations between the positive and negative syndrome dichotomy
and the qEEG were observed.

Conclusions. This study lends support to the factor analysis of psychopathology, and specifically the
tripartite syndrome model of schizophrenia, as a step in explicating the biological dimensions of the
disorder.
The prevalence of Gilles de la Tourette syndrome in
children and adolescents with autism: a large scale study
Authors: BARON-COHEN S. , SCAHILL V. L. , IZAGUIRRE J. , HORNSEY H. , ROBERTSON M. M.
Published: July 2002

Background. An earlier small-scale study of children with autism revealed that 8·1% of such
patients were co-morbid for Gilles de la Tourette syndrome (GTS). The present study is a large scale
test of whether this result replicates.

Method. Four hundred and forty-seven pupils from nine schools for children and adolescents with
autism were screened for the presence of motor and vocal tics.

Results. Subsequent family interviews confirmed the co-morbid diagnosis of definite GTS in 19
children, giving a prevalence rate of 4·3%. A further 10 children were diagnosed with probable GTS
(2·2%).

Conclusions. These results indicate that the rate of GTS in autism exceeds that expected by chance,
and the combined rate (6·5%) is similar to the rates found in the smaller-scale study. Methodological
considerations and alternative explanations for an increased prevalence are discussed.
Pascal's wager revisited
Authors: Jordan Jeff
Published: July 2002

Pascal's wager attempts to provide a prudential reason in
support of
the rationality of believing that God exists. The wager employs the idea
that the
utility of theistic belief, if true, is infinite, and in this way, the
expected utility of
theism swamps that of any of its rivals.

Not surprisingly the wager generates more than a good share of philosophical

criticism. In this essay I examine two recent objections levelled against
the wager
and I argue that each fails. Following this, I argue that a transfinite
version of the
wager – one using the idea of an infinite utility – is incompatible
with standard
axiomatic constructions of decision-theory and, as a consequence, the Pascalian

would be well-advised to give up the idea of an infinite utility and employ
only a
finite version of the wager. The consequences of limiting the wager to
finite utilities
are also explored.
Social Policy Digest NUMBER ONE HUNDRED AND THIRTEEN May to July 1999
Authors: BENNETT FRAN
Published: July 2002

Contents

1 Social security and income maintenance

2 Health (formerly 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 Government (formerly Local government)

11 Gender

12 Demography
Ron Scollon & Suzanne Wong Scollon, Intercultural
communication: A discourse approach. (Language in
society, 21.) Oxford (UK) & Cambridge (MA): Blackwell,
1995. Pp. xiii, 271.
Authors: Kakavá Christina
Published: July 2002

Designing for the first time an undergraduate Cross-Cultural
Communication course for a liberal arts college, I was
faced with the quandary of how to communicate to my students
all that I wanted to teach them about face, politeness,
power, communicative style, and discourse – without
having to ask them to purchase a very expensive packet
of readings. It seems that academic providence took care
of me, because at that point the Scollons' book was
published. Since then I have used it with great success
in my class, which serves students across the spectrum
of disciplines.
Jan Blommaert & Jef Verschueren. Debating
diversity: Analysing the discourse of tolerance. London:
Routledge, 1998. Pp. xiv, 233 pp. Pb $22.99.
Authors: Bucholtz Mary
Published: July 2002

Debating diversity, a pragmatic analysis
of official liberal discourse concerning migration in Flemish
Belgium, is a thorough, topical, and relevant treatment
of the widespread yet near-invisible forms of racism that
pervade public discourse on cultural difference. Electing
not to focus on the far more widely recognized phenomenon
of right-wing racism, the authors instead offer a careful
critique that makes clear that the left is by no means
immune to racism in its policies and practices. Following
in the wake of research by a number of other politically
oriented discourse analysts, this volume addresses how
racism manifests itself in discourse. It therefore serves
as an important reminder that ideologies are constructed,
and hence contingent and changeable. Because of the broad
scope of its inquiry and the relatively accessible methods
it employs, it will be of interest to scholars in many
fields, including anthropology, communication, political
science, race and ethnic studies, and sociology, as well
as linguistics. Despite its sometimes overwhelming wealth
of detail, it may also appeal to a nonacademic readership,
as did the Dutch version of the book when it was first
published in Belgium.
Anneli Sarhimaa, Syntactic transfer, contact-induced
change, and the evolution of bilingual mixed codes: Focus
on Karelian-Russian language alternation. Helsinki:
Finnish Literature Society, 1999. Pp. 340.
Authors: Dorian Nancy C.
Published: July 2002

The data that underlie Anneli Sarhimaa's excellent
study were gathered between 1989 and 1992, under restrictive
field circumstances. Visits to Karelia required what the
author terms “intricate co-operation with academic
and public authorities in Russia” (p. 76), and the
duration of any stay was limited to a few weeks. From her
home base in Finland, she made short visits to three Central
Karelian villages in the summers of 1989 and 1991, working
with additional Central Karelian speakers resident in the
capital city of Karelia in the winters of 1990 and 1991;
in 1992, a two-week trip allowed her to work in nine Tver
Karelian villages in central Russia. That these compressed
visits produced 30-some hours of taped interviews and 31
sets of translation-task data (15 Central Karelian, 16
Tver Karelian) does credit to her careful advance planning;
the frankness with which she points to limitations in the
resulting data does equal credit to her scholarly scrupulousness.
Interaction, function words, and the wider goals of speech perception
Authors: Shillcock Richard
Published: July 2002

We urge caution in generalising from content words to function words, in which lexical-to-phonemic feedback might be more likely. Speech perception involves more than word recognition; feedback might be outside the narrow logic of word identification but still be present for other purposes. Finally, we raise the issue of evidence from imaging studies of auditory hallucination.
Dream production is not chaotic
Authors: Mancia Mauro
Published: July 2002

The AIM model proposed by Hobson et al. is interesting: We know the neurophysiological aspects of the activation process (A) and the external input (I), but very little about the internal input and neurocognitive process (M). Internal input could be an expression of unconscious experiences memorised by the subject containing his emotional and cognitive history. Therefore internal input could not be chaotic but might have an emotional and affective sense bound to the unconscious. The fact that dreams are present in the absence of REM sleep means that they may originate from other structures besides the pons. These structures may represent the archives of dreamer's affective history.

[Hobson et al.; Solms]
Real self-deception
Authors: Mele Alfred R.
Published: July 2002

Self-deception is made unnecessarily puzzling by
the assumption that it is an intrapersonal analog of ordinary
interpersonal deception. In paradigmatic cases, interpersonal
deception is intentional and involves some time at which the
deceiver disbelieves what the deceived believes. The assumption
that self-deception is intentional and that the self-deceiver believes
that some proposition is true while also believing that it is false
produces interesting conceptual puzzles, but it also produces a
fundamentally mistaken view of the dynamics of self-deception.
This target article challenges the assumption and presents an
alternative view of the nature and etiology of self-deception.
Drawing upon empirical studies of cognitive biases, it resolves
familiar “paradoxes” about the dynamics of self-
deception and the condition of being self-deceived. Conceptually
sufficient conditions for self-deception are offered and putative
empirical demonstrations of a kind of self-deception in which a
subject believes that a proposition is true while also believing that
it is false are criticized. Self-deception is neither irresolvably
paradoxical nor mysterious, and it is explicable without the
assistance of mental exotica. The key to understanding its dynamics
is a proper appreciation of our capacity for acquiring and retaining
motivationally biased beliefs.
The role of memory in planning and pretense
Authors: Gärdenfors Peter
Published: July 2002

Corresponding to Glenberg's distinction between the
automatic and effortful modes of memory, I propose a distinction
between cued and detached mental representations. A cued
representation stands for something that is present in the external
situation of the representing organism, while a detached
representation stands for objects or events that are not present in
the current situation. This distinction is important for understanding
the role of memory in different cognitive functions like planning and
pretense.
Pointing the way to a unified theory of action and perception
Authors: Goodale Mel
Published: July 2002

Deictic coding offers a useful model for understanding the
interactions between the dorsal and ventral streams of visual
processing in the cerebral cortex. By extending Ballard et al.'s
ideas on teleassistance, I show how dedicated low-level visuomotor
processes in the dorsal stream might be engaged for the services
of high-level cognitive operations in the ventral stream.
Testing the limits of the ontogenetic sources of talent and excellence
Authors: Baltes Paul B.
Published: July 2002

Experiential factors such as long-term deliberate practice
are powerful and necessary conditions for outstanding achievement.
Nevertheless, to be able to reject the role of biology based
individual differences (including genetic ones) in the manifestation
of talent requires designs that expose heterogeneous samples to
so-called testing-the-limits conditions, allowing asymptotic levels
of performance to be analyzed comparatively. When such research
has been conducted, as in the field of lifespan cognition, individual
differences, including biology based ones, come to the fore and
demonstrate that the orchestration of excellence requires joint
attention to genetic–biological and experiential
factors.
Context updating and the P300
Authors: Donchin Emanuel , Coles Michael G. H.
Published: July 2002

We concur with Sommer et al. that the processing manifested by
P300 is not necessarily conscious. We also note that Verleger is yet
again adducing evidence that contradicts an assertion we never
made.
Etiological classification and the acquisition and structure of knowledge
Authors: Ghiselin Michael T.
Published: July 2002

Millikan's account of how we acquire our most basic
concepts might be clarified by a better ontological taxonomy,
especially one that distinguishes between natural kinds on the one
hand and wholes composed of parts on the other. The two have a
different causal basis, which is important because once classification
goes beyond the stage of naive induction, it becomes fundamentally
etiological.
Use impacts morphological representation
Authors: Bybee Joan
Published: July 2002

The distinction between regular and irregular morphology is not clear-cut enough to suggest two distinct modular structures. Instead, regularity is tied directly to the type frequency of a pattern. Evidence from experiments as well as from naturally occurring sound change suggests that even regular forms have lexical storage. Finally, the development trajectory entailed by the dual-processing model is much more complex than that entailed by associative network models.
Perceptual symbols in language comprehension
Authors: Glenberg Arthur M.
Published: July 2002

Barsalou proposes (sect. 4.1.6) that perceptual symbols play a
role in language processing. Data from our laboratory document this role
and suggest the sorts of constraints used by simulators during language
comprehension.
Rose succeeds where Wilson fails
Authors: Hirsch Jerry
Published: July 2002

Rose's accomplishment in combining ontological unity with
epistemological diversity contrasts it with Wilson's failure in
overemphasizing the former and not appreciating the latter. This
commentary cites the two most authoritative discussions of the
inapplicability of heritability to human data, corrects several
historical errors or inaccuracies in genetics, and criticizes
the characterizations of Jacques Loeb and Robert Plomin.
Episodic memory: It's about time (and space)
Authors: Nadel Lynn , Ryan Lee , Keil Katrina , Putnam Karen
Published: July 2002

Aggleton & Brown rightly point out the shortcomings of the
medial temporal lobe hypothesis as an approach to anterograde amnesia.
Their broader perspective is a necessary corrective, and one hopes it
will be taken very seriously. Although they correctly note the dangers
of conflating recognition and recall, they themselves make a similar
mistake in discussing familiarity; we suggest an alternative approach.
We also discuss implications of their view for an analysis of
retrograde amnesia. The notion that there are two routes by which
the hippocampus can reactivate neuronal ensembles in the neocortex
could help us understand some currently puzzling facts about the
dynamics of memory consolidation.
Facing complexity: Against scientific oversimplification
Authors: Palm Guenther
Published: July 2002

Steven Rose's book is essentially a plea for considering
the variety and complexity of life and against simplistic reductions
of human and animal behavioral phenomena to single genetic causes.
Adding depth to the picture
Authors: Van Gisbergen J.A.M. , Chaturvedi V.
Published: July 2002

Recent studies showing that pontine burst cells carry a monocular code for rapid eye movements raise questions about the organisation of signals at more central levels. Evidence that the superior colliculus may also be involved in the coding of movements in depth is reviewed. Recent work showing that the global effect is a property of refixations in 3-D space is another indication that the oculomotor systems for direction and depth are centrally coupled.
The functional neuroanatomy of inflectional morphology
Authors: Ullman Michael T.
Published: July 2002

Clahsen has presented an impressive range of psycholinguistic data from German regular and irregular inflection to support the view that lexical memory and the combinatorial operations of grammar are subserved by distinct mental mechanisms. Most of the data are convincing and important. I particularly applaud Clahsen's effort to extend this lexical/grammatical dichotomy from mind to brain. Here I discuss some problems with the evidence presented by Clahsen in support of a neural lexical/grammatical dichotomy, and offer some additional evidence to reinforce this neural distinction.
On stochastic behavior of perturbed Hamiltonian systems
Authors: BRIN MICHAEL , FREIDLIN MARK
Published: July 2002

We consider deterministic perturbations $\ddot q^\varepsilon(t)+F'(q^\varepsilon(t))=\varepsilon b(\dot q^\varepsilon(t),q^\varepsilon(t))$ of an oscillator $\ddot q+F'(q)=0$, $q\in{\mathbb R}^1$. Assume that $\lim_{|q|\to\infty}F(q)=\infty$ and that $F'(q)$ has a finite number of nondegenerate zeros. For a generic $F$, if $\partial b/\partial\dot q<0$ (as in the case of friction), then typical orbits are attracted to points where $F$ has a local minimum. For $0<\varepsilon\ll1$, the equilibrium to which the trajectory is attracted is ‘random’. To study this randomness, which is caused by the sensitive behavior of trajectories near the saddle points, we consider the graph $\Gamma$ homeomorphic to the space of connected components of the level sets of the Hamiltonian $H(p,q)=p^2/2+F(q)$. We show that, as $\varepsilon\to0$, the slow component of $(p^\epsilon(t/\epsilon),q^\epsilon(t/\epsilon))$ tends to a certain stochastic process on $\Gamma$ which is deterministic inside the edges and branches at the interior vertices into adjacent edges with probabilities which can be calculated through the Hamiltonian $H$ and the perturbation $b$.
Non-stationarity of isomorphism between AF algebras defined by stationary Bratteli diagrams
Authors: BRATTELI OLA , JØRGENSEN PALLE E. T. , HANG KIM KI , ROUSH FRED
Published: July 2002

We first study situations where the stable AF algebras defined by two square primitive non-singular incidence matrices with non-negative integer matrix elements are isomorphic, even though no powers of the associated automorphisms of thecorresponding dimension groups are isomorphic. More generally we consider necessary and sufficient conditions for two such matrices to determine isomorphic dimension groups.We give several examples.
Isomorphism classes of products of powers for graphic flows
Authors: AUSLANDER J. , MARKLEY N.
Published: July 2002

A graphic flow is a totally minimal flow such that the only
minimal subsets of the product flow are the graphs of the powers
of the defining homeomorphism [2]. We consider flows of the
form $(X^{k},T^{L})$, where $(X,T)$ is graphic, $k$ is a positive
integer, and $L:\{1,\ldots,k\}\to {\Bbb Z}\setminus \{0\}$. It is
shown that the isomorphism classes of these flows are
determined by the cardinality of $L^{-1}(p)$.
Local rigidity of Anosov higher-rank lattice actions
Authors: QIAN NANTIAN , YUE CHENGBO
Published: July 2002

Let $\rho_0$ be the standard action of a higher-rank lattice $\Gamma$ on a torus by automorphisms induced by a homomorphism $\pi_0:\Gamma\to SL(n,{\Bbb Z})$. Assume that there exists an abelian group ${\cal A}\subset \Gamma$ such that $\pi_0({\cal A})$ satisfies the following conditions: (1) ${\cal A}$ is ${\Bbb R}$-diagonalizable; (2) there exists an element $a\in {\cal A}$, such that none of its eigenvalues $\lambda_1,\dots,\lambda_n$ has unit absolute value, and for all $i,j,k=1,\dots,n$, $|\lambda_i\lambda_j|\neq|\lambda_k|$; (3) for each Lyapunov functional $\chi_i$, there exist finitely many elements $a_j\in {\cal A}$ such that $E_{\chi_i}=\cap_{j} E^u(a_j)$ (see \S1 for definitions). Then $\rho_0$ is locally rigid. This local rigidity result differs from earlier ones in that it does not require a certain one-dimensionality condition.
Maximal and pointwise ergodic theorems for word-hyperbolic groups
Authors: FUJIWARA KOJI , NEVO AMOS
Published: July 2002

Let $\Gamma$ denote a word-hyperbolic group, and let $S=S^{-1}$ denote a finite symmetric set of generators. Let $S_n = \{w: |w| = n \}$ denote the sphere of radius $n$, where $|\cdot|$ denotes the word length on $\Gamma$ induced by $S$. Define $\s_n \deq (1/{\#S_n}) \sum_{w \in S_n}w$, and $\mu_n=(1/(n+1))\sum_{k=0}^n \s_k$. Let $(X,{\cal B},m)$ be a probability space on which $\Gamma$ acts ergodically by measure-preserving transformations. We prove a strong maximal inequality in $L^2$ for the maximal operator $f_{\mu}^*=\sup_{n\ge 0}|\mu_n f(x)|$. The maximal inequality is applied to prove a pointwise ergodic theorem in $L^2$ for exponentially mixing actions of $\Gamma$ of the following form: $\mu_n f(x) \to \int_X f\,dm$ almost everywhere and in the $L^2$-norm, for every $f\in L^2(X)$. As a corollary, for a uniform lattice $\Gamma \subset G$, where $G$ is a simple Lie group of real rank one, we obtain a pointwise ergodic theorem for the action of $\Gamma$ on an arbitrary ergodic $G$-space. In particular, this result holds when $X=G/\Lambda$ is a compact homogeneous space, and yields an equidistribution result for sets of lattice points of the form $\Gamma g$, for almost every $g\in G$.
Embedding covariance algebras of flows into $AF$-algebras
Authors: PIMSNER MICHAEL V.
Published: July 2002

Suppose that $\{\alpha_t\}_{t\in \mathbb{R}}$ is a flow on the compact metrizable space $X$. We prove that a necessary and sufficient condition for the existence of an embedding (injective $*$-homomorphism) of the crossed product $C(X)\rtimes_\alpha \mathbb{R}$ into some $AF$-algebra is that every point of $X$ be chain recurrent in the sense of Conley.
Bi-invariant sets and measures have integer Hausdorff dimension
Authors: MEIRI DAVID , PERES YUVAL
Published: July 2002

Let $A,B$ be two diagonal endomorphisms of the $d$-dimensional torus with corresponding eigenvalues relatively prime. We show that for any $A$-invariant ergodic measure $\mu$, there exists a projection onto a torus ${\mathbb T}^r$ of dimension $r\ge\dim\mu$, that maps $\mu$-almost every $B$-orbit to a uniformly distributed sequence in ${\mathbb T}^r$. As a corollary we obtain that the Hausdorff dimension of any bi-invariant measure, as well as any closed bi-invariant set, is an integer.
Positive exponent in families with flat critical point
Authors: THUNBERG HANS
Published: July 2002

It is known that in generic, full unimodal families with a critical point of finite order, there exists a set of positive measure in parameter space such that the corresponding maps have chaotic behaviour. In this paper we prove the corresponding statement for certain families of unimodal maps with flat critical point. One of the key-points is a large deviation argument for sums of ‘almost’ independent random variables with only finitely many moments.
Identity Foreclosure: Women's Experiences of Widowhood as Expressed

in Autobiographical Accounts
Authors: VAN DEN HOONAARD DEBORAH KESTIN
Published: July 2002

This article addresses the issue of the loss of identity a woman
experiences

when she becomes a widow. Based on an analysis of published autobiographical

accounts of widowhood, it looks at how women express their

experience of losing their husbands. It explicates a process of ‘identity

foreclosure’ which strips a woman of her identity at every level,
and the

process by which the authors of these accounts have built new identities.

Extensive quoting from the published accounts reveals the richness of these

data and provides a feeling for the emotional impact of widowhood that

women experience.
The roles of friends and neighbours in providing support for older people
Authors: NOCON ANDREW , PEARSON MAGGIE
Published: July 2002

Most published research on informal care for older people focuses on the
support provided by relatives. The role of non-kin carers can, however, also
be significant in supporting older people in their own homes. In this paper, we
report the findings from an exploratory study of the support provided by
friends and neighbours who are the main carers of frail older people. It draws
on interviews with an opportunistic sample of friends, neighbours and older
people, which explored their views about the support arrangements, the
reasons why help was provided and any difficulties experienced. Several
friends and neighbours provided intensive and frequent help, and some played
a key role in co-ordinating other services. One of the main forms of direct
support related to older people's quality of life, at a broader level than the
practical help provided by statutory services. The flexibility of such support,
and the friends' and neighbours' concern for older people as individuals, were
particularly important to the people they helped. Nevertheless, such help was
not provided without costs to the carers. The study highlights the need for
policy-makers and practitioners not to take help from friends and neighbours
for granted and, in line with the White Paper Modernising Social Services, to
provide the support services they need.
South Africa's morality tale for our time
Authors: GUELKE ADRIAN
Published: July 2002

Truth and Reconciliation Commission of South Africa Report: Five Volumes, Basingstoke and Oxford, Macmillan, 1999

On 29 October 1998 Archbishop Desmond Tutu presented the final report of the
Truth and Reconciliation Commission to President Nelson Mandela. This massive
report has now been published by Macmillan in a handsome, extensively illustrated
five-volume set. The fine quality of the production would seem appropriate to what
has been hailed as a document of lasting importance for South Africa. Indeed, it is
evident that many foreign commentators see it as important not just for South
Africa but for the whole world. That has been reflected in the interest shown in the
TRC by commentators, such as Timothy Garton Ash and Michael Ignatieff, who
have not previously written about South Africa. The report was the culmination of
nearly three years of work by the TRC. President Mandela announced the names of
the 17 commissioners (designating Desmond Tutu as chairperson and Alex Boraine
as deputy chairperson) in November 1995. It began to function in December that
year, while the first public hearings were held on 15 April 1996. However, while the
report has been the most significant product of the TRC's endeavours, it is not the
end of its work. In particular, the Committee on Amnesty will continue to function
until it has reached decisions on all the outstanding applications for amnesty
received by the deadline of 30 September 1997. When it has completed this task a
further volume of the final report will be published.
The altered state and the state of nature—the French Revolution and international politics
Authors: BUKOVANSKY MLADA
Published: July 2002

The case of the French Revolution supports the proposition that principles of political legitimacy which shape state identities are linked to domestic social structures, and help determine the resources states mobilize in international competition. To the degree that they are shared across states, legitimacy principles also shape international society. The enactment of a deviant principle of legitimacy by a major power will have systemic consequences because it undermines the existing rules of the game; it may have transformative effects if the efficacy of the new principle is demonstrated in competition. Closer attention should be paid to the complex manner in which new principles interact with existing rules of international society.
Jim Crow laws of the 1890s and the origins of New Orleans jazz: correction of an error
Authors: Johnson Jerah
Published: July 2002

A seriously misleading error has crept into almost all the literature on the origins of New Orleans jazz. The error mistakenly attributes to the Jim Crow laws of the 1890s a significant role in the formation of the city's jazz tradition.

Jazz historians have done a reasonably good job of depicting the two black communities that existed in new Orleans from the time of the Louisiana Purchase in 1803 until the twentieth century. One community comprised a French-speaking Catholic group who lived mostly in downtown New Orleans, i.e. the area of the city down-river from Canal Street. Before the Civil War this group, commonly called Creoles, or Black Creoles, but more accurately called Franco-Africans, comprised free people of colour as well as slaves, and after the war consisted of their descendants who perpetuated the group's language, religion and musical tradition, which combined French, African and Caribbean elements.

Members of the other black community were English-speaking Protestants who lived mostly in uptown new Orleans. That group, before the Civil War, was made up largely of slaves brought to New Orleans by Americans who flooded into Louisiana after the 1803 Purchase, though it also included some free people of colour. After the war, the descendants of these immigrants continued their language, religion and musical tradition, which came mostly from the rural South. There Anglo-Africans were generally less prosperous and less educated than the downtown Franco-African or Creole community.
Contribution to the study of dynamics and dynamic control of
robots interacting with dynamic environment
Authors: Vukobratovic Miomir , Potkonjak Veljko , Matijevic Vladimir
Published: July 2002

The paper
discusses some practical problems of contact dynamics. Modelling the dynamics
of contact tasks is carried out in a completely general
way. Two dynamic systems, active robot system and passive environment
system are brought into contact and the relevant dynamics are
analyzed. The effects are: rigid-body contact force, elastodynamics in contact
zone, friction in contact points, etc. Simultaneous stabilization of contact
force and position is obtained using New Dynamic Position/Force Control.
The general model is then applied to some more concrete
problems and the simulation results are presented.
A linear differential formulation of friction forces for adaptive estimator

algorithms
Authors: Tsaprounis C. J. , Aspragathos N. A.
Published: July 2002

In this paper a new approach for the formulation of the friction forces velocity function is introduced. The scope of this formulation is to facilitate the implementation of control laws for systems where friction forces appear. The friction

model includes the exponential decay part, the Coulomb and viscous friction. The introduced formulation is based on the observation that the friction coefficient function of velocity can be presented as the solution of a linear differential equation. Due to this linearity, the parameters of the derived differential equation can be estimated easily by an adaptive system. The estimation of these parameters is equivalent to the estimation of the friction coefficient in the full range of operational velocities. This knowledge gives to the designed control systems the potential to avoid successfully the stick-slip phenomenon.

A control law for one D.O.F. system, where friction appears, is designed in order to prove the applicability of the proposed formulation of the friction model in control systems. A MRAC adaptive algorithm estimates the differential friction model parameters, using the measured friction force, while a sliding controller adjusts the motion of the mechanical system. The proposed friction model can be used in any control system where friction forces have to be compensated. The linear form of the model is suitable for common adaptive estimators. Therefore, the proposed structure is suitable for robotic applications, such as assembly, deburring, etc.
Neural network sliding mode robot control
Authors: Jezernik Karel , Rodič Miran , šafarič Riko , Curk Boris
Published: July 2002

This paper develops a method for neural network control design with sliding modes in which robustness is inherent. Neural network control is formulated to become a class of variable structure (VSS) control. Sliding modes are used to determine best values for parameters in neural network learning rules, thereby robustness in learning control can be improved. A switching manifold is prescribed and the phase trajectory is demanded to satisfy both, the reaching condition and the sliding condition for sliding modes.
Modelling of a camera-3D range finder system
Authors: Barat Christian , Triboulet Jean , Chekhar Youcef , Colle Etienne
Published: July 2002

A laser range finder mounted on a site and azimuth turret is used as a 3D range camera. It forms, associated with a video camera, an original stereovision system. The internal structure of both images are the same but the resolution of 3D image stays low. By ignoring the acquiring speed of measures, spatial resolution is limited by the accuracy of deviation device and the laser footprint. The fact that the impact of the beam is not a point introduces spatial integration.

To correct the average at depth discontinuities due to the beam footprint, a neural-network-based solution is reported.

The use of such a multisensor system requires its calibration. As camera calibration is a well-known problem, the paper focuses on models and calibration methods of the range finder. Experimental results illustrate the quality of the calibration step in terms of accuracy and stability.

The footprint correction is evaluated for both 1D and 2D range finder scannings.
Kinematics and
dynamics of a six-degree-of-freedom parallel manipulator with revolute
legs
Authors: Zanganeh Kourosh E. , Sinatra Rosario , Angeles Jorge
Published: July 2002

This paper presents the kinematics and dynamics of a
six-degree-of-freedom platform-type parallel manipulator with six revolute legs,
i.e. each leg consists of two links that are connected by a revolute joint.
Moreover, each leg is connected, in turn, to the base and moving platforms by
means of universal and spherical joints, respectively. We first introduce a
kinematic model for the manipulator under study. Then, this model is used to
derive the kinematics relations of the manipulator at the displacement, velocity
and acceleration levels. Based on the proposed model, we develop the dynamics
equations of the manipulator using the method of the natural orthogonal
complement. The implementation of the model is illustrated by computer
simulation and numerical results are presented for a sample trajectory in the
Cartesian space.
Ultrasonic classification and location of 3D room features
using maximum likelihood estimation - Part I
Authors: Mun-Li Hong , Kleeman Lindsay
Published: July 2002

Current mobile robot ultrasonic localisation techniques use sensor systems which rely on features in a horizontal plane. The implicit assumption is that the room boundary on the horizontal plane is not obstructed by objects such as furniture. This assumption is often not realistic and restricts the versatility and portability of these systems. The solution proposed in this paper is the provision of sensing flexibility to use other 3D room boundaries (e.g. ceiling-wall intersections) as 3D natural beacons. We propose a 3D ultrasonic sensor array that uses a Maximum Likelihood Estimator to match the echo arrival times to different object classes and to determine the location of the 3D target. This method does not require fast data acquisition or powerful computing. It has been implemented on a robot localisation application with the Extended Kalman Filter. This paper is the first of two parts, and presents theoretical results on target classification and minimum transducer requirements. The second part, in the next issue of Robotica, presents experimental results on the characterisation of the sensor and its application to robot localisation, and includes the references for the both papers.
Conference Reports
Authors: Khalil Wisama
Published: July 2002

FIFTH IFAC SYMPOSIUM ON ROBOTS CONTROL SYROCO '97 (3–5 SEPTEMBER 1997)

SYROCO '97 was the fifth of the IFAC series of triennial Symposia on Robot Control. Previous events were held in Barcelona (Spain), 1985; Karlsruhe (Germany), 1988; Vienna (Austria), 1991 and Capri (Italy), 1994. SYROCO '97 was held from September 3
to 5, 1997 in the “Cité des Congrès” in Nantes, France. The Chairman of the International Programme Committee was Bernard ESPIAU from INRIA Rhône Alpes (FRANCE); the Chairman of the National Organizing committee was Wisama KHALIL from IRCyN (Ecole Centrale de Nantes-FRANCE).
The hidden economy of esteem
Authors: Brennan Geoffrey , Pettit Philip
Published: July 2002

A generation of social theorists have argued that if free-rider considerations show that certain collective action predicaments are unresolvable under individual, rational choice – unresolvable under an arrangement where each is free to pursue their own relative advantage – then those considerations will equally show that the predicaments cannot be resolved by recourse to norms (Buchanan, 1975, p. 132; Heath, 1976, p. 30; Sober and Wilson, 1998, 156ff; Taylor, 1987, p. 144). If free-rider considerations explain why people do not spontaneously keep the streets clean, though they would each prefer unlittered streets, then those considerations will also explain why there is no effective norm against littering the streets.
THE U.K. HUMAN FERTILISATION AND EMBRYOLOGY AUTHORITY
Authors: Doyle Pat
Published: July 2002

The Human Fertilisation and Embryology Act of the United Kingdom was passed
in 1990, leading to the formation of the Human Fertilisation and Embryology
Authority (HFEA), the first statutory body to regulate and control assisted
conception anywhere in the world. The principal function of the HFEA is to
license and monitor clinics that carry out in vitro fertilization (IVF), donor
insemination (DI), and embryo research. Information on over 135,000 treatment
cycles, 20,000 pregnancies, and 25,000 babies following IVF has now been
collected as part of the regulatory process, and these data have permitted
unbiased and accurate evaluation of treatment efficacy using pregnancy and
live-birth rates. The treating clinics are required by law to provide
information on the outcome of all births, including neonatal mortality and
congenital malformations, but there is no systematic validation of these data
using medical records or any follow-up of treated women, or babies, over time.
In addition, the strict confidentiality of data supplied to the HFEA means
that outside researchers have been unable to access the database for research
projects. Thus, at the present time, it is not possible to evaluate the
long-term safety of assisted conception procedures using HFEA data. There is
reasonable scientific evidence to justify full investigation of the health of
both treated women and resulting children. Particular health outcomes
requiring evaluation include obstetric complications, preterm births, cerebral
palsy, and cancer. The HFEA has recognized the need for follow-up studies and
is currently investigating ways of enabling research projects using HFEA data
to be undertaken.
AN AUTOREGRESSIVE SPECTRAL DENSITY ESTIMATOR AT FREQUENCY
ZERO FOR NONSTATIONARITY TESTS
Authors: Perron Pierre , Ng Serena
Published: July 2002

Many unit root and cointegration tests require
an estimate of the spectral density function at frequency
zero of some process. Commonly used are kernel estimators
based on weighted sums of autocovariances constructed using
estimated residuals from an AR(1) regression. However,
it is known that with substantially correlated errors,
the OLS estimate of the AR(1) parameter is severely biased.
In this paper, we first show that this least-squares bias
induces a significant increase in the bias and mean-squared
error (MSE) of kernel-based estimators. We then consider
a variant of the autoregressive spectral density estimator
that does not share these shortcomings because it bypasses
the use of the estimate from the AR(1) regression. Simulations
and local asymptotic analyses show its bias and MSE to
be much smaller than those of a kernel-based estimator
when there is strong negative serial correlation. We also
include a discussion about the appropriate choice of the
truncation lag.
MULTIVARIATE TIME SERIES WITH VARIOUS HIDDEN UNIT ROOTS, PART II
Authors: Gregoir Stéphane
Published: July 2002

This paper extends the statistical results obtained
by Gregoir and Laroque (1994, Journal of Econometrics
63, 183–214). It develops statistical tools to analyze
multivariate time series that can be represented under
an autoregressive equation of finite order with various
polynomial error correction terms at various frequencies
with possibly a non-null deterministic part as introduced
by Gregoir (1999, Econometric Theory 15, 435–468).
We propose an estimation procedure that proceeds through
repeated applications of principal component analysis and
a specification test for the omission of a polynomial relation
of cointegration at each frequency.
Long-term tree ring chronologies from sympatric tropical dry-forest trees: individualistic responses to climatic variation
Authors: ENQUIST BRIAN J. , LEFFLER A. JOSHUA
Published: July 2002

The influence of local precipitation and temperature on long-term growth dynamics in two species of
seasonally dry tropical forest trees were investigated. Growth records were extracted from tree rings in Guanacaste
province, Costa Rica. These chronologies provide a long-term (c. 85-y) record of tree growth for two species with
contrasting phenologies. Annual growth, in both species, was dependent on annual and/or monthly variation in local
precipitation but less so on temperature. For each species, however, patterns of growth reflected unique degrees of
sensitivity to monthly rainfall and rainfall during previous years. It is hypothesized that such differences were due to
the rooting depth of these species. A review of the literature also indicated similar diverse cambial growth responses
by tropical trees to variation in annual and monthly climate. Lastly, it was shown that variation in longer term
fluctuations in the Pacific and Atlantic oceans, as measured by the El Niño Southern Oscillation (ENSO) and North
Atlantic Oscillation (NAO), significantly influenced local precipitation in Guanacaste only during the wettest portion
of the wet season. Such temporal sensitivity may have differentially influenced the longer-term growth of some tropical
tree species but not others. Together, these results support the hypothesis that tropical tree species respond
individualistically to variation in local and regional climate and that some tropical assemblages may in fact be structured by
species-specific differences in soil water-use.
Ecological relationships among sympatric lizards in a transitional forest in the northern Amazon of Brazil
Authors: VITT LAURIE J. , ZANI PETER A.
Published: July 2002

Sympatric lizards in a transitional forest of Roraima, Brazil, dividing Amazon rain forest from savanna, contained a lizard assemblage of 16 species representing six families. Lizards varied in size, activity (diurnal versus nocturnal), microhabitats used, exposure to various conditions of light availability, prey types, and prey sizes. Overlaps in microhabitat occurrence varied from 0 (no overlap) to 1.0 (total overlap) whereas overlaps in prey types varied from 0.005 to 0.607. Microhabitat overlaps were higher overall than dietary overlaps. Pseudocommunity analyses on microhabitat data indicate that the community is not randomly assembled and that two distinct guilds exist, a leaf-litter guild and an arboreal guild, each with four species. Similar analyses on diet data revealed no apparent guild structure ast the first rank (nearest neighbour). Lizard diets did not differ from a random assortment based on prey type. At lower levels, the assemblage was structured with respect to food. Variation in prey use among lizard species was tied more closely to the effect of lizard body size on prey size (lizards ate different-sized prey items). Although exploitative competition among species may maintain structure within this assemblage it does not necessarily cause the observed differences. Several species are nearly identical ecologically to sister taxa in other environments and within different lizard assemblages suggesting that composition of the local assemblage limits the species that can enter the assemblage. Finally, lack of structure at the lowest (most similar) neighbour ranks may reflect the impact of a transitional habitat on stability of species interactions at the local level.
A NOTE ON PERTURBATION ANALYSIS ESTIMATORS FOR AMERICAN-STYLE
OPTIONS
Authors: Fu* Michael C. , Wu Rongwen , Gürkan Gül , Demir A. Yonca
Published: July 2002

In this note, we correct an error in the paper
by Fu and Hu [1] for the perturbation analysis
estimator given for the gradient of an American call option
payoff on an underlying asset paying multiple dividends.
We then introduce a different asset price model that is
more straightforward than the previous model, and derive
the corresponding gradient estimators. We conclude with
a brief discussion of extensions of the estimator to other
American-style options.
ON TRUNCATION PROPERTIES OF FINITE-BUFFER QUEUES AND QUEUEING
NETWORKS
Authors: Chao Xiuli , Miyazawa Masakiyo
Published: July 2002

We show that several truncation properties of queueing
systems are consequences of a simple property of censored
stochastic processes. We first consider a discrete-time
stochastic process and show that its censored process has
a truncated stationary distribution. When the stochastic
process has continuous time, we present a similar result
under the additional condition that the process is locally
balanced. We apply these results to single-server batch
arrival batch service queues with finite buffers and queueing
networks with finite buffers and batch movements, and extend
the well-known results on truncation properties of the
MX/G/1/k queues
and queueing networks with jump-over blocking.
CONTRASTIVE SOCIOLINGUISTICS.Marlis Hellinger and Ulrich
Ammon (Eds.). Berlin: Mouton de Gruyter, 1996. Pp. vii + 504. DM 228 cloth.
Authors: Bernsten Jan
Published: July 2002

Hellinger and Ammon have compiled a volume of 21 papers that cover a broad range of
sociolinguistic topics, with a primary focus on Western Europe. In their introduction, the editors
consider approaches to sociolinguistics, grounding this volume in Hymes' original
discussion of language as a social phenomenon. According to the editors, the authors of these
papers “seek to relate findings to underlying social, cultural or political structures”
(p. 4).
INTERROGATIVE CHUNKS IN FRENCH L2
Authors: Myles Florence , Mitchell Rosamond , Hooper Janet
Published: July 2002

This paper explores the relationship between formulaic language and creative
construction in SLA by examining the production of interrogatives in an extensive naturalistic
corpus of L2 French produced by early classroom learners. The paper first analyzes the
production and breakdown of such formulaic language over time, before exploring the
development of more creative structures. The interaction between the two processes “rote
learning of formulas and creative construction” is then investigated. This interaction is
shown to be a dynamic two-way process, with learners being driven forward in the development
of their L2 system by their attempts to resolve the tension between structurally complex but
communicatively rich formulas on the one hand, and structurally simple but communicatively
inadequate creative structures on the other hand.