bluuebunny/crossref_metadata_2025 huggingface dataset:
Moderating power: a Thucydidean perspective
Authors: KOKAZ NANCY
Published: July 2002

Thucydides is generally regarded as the founder of Realism in IR because of his vivid descriptions of war and power politics. A strong Realist account rests on sharp dichotomies between domestic and international politics, power and justice, nature and convention. Reading Thucydides through these dichotomies is not limited to IR; in fact, most classical and philosophical scholarship on the historian is informed by this vocabulary. I argue that such readings cannot hold under close scrutiny because they turn Thucydides too much into a sophist. As closer attention to how nature and convention, power and justice, domestic and international are deployed in the History reveals, Thucydides is deeply concerned with moving beyond standard sophistic oppositions. He does this by articulating a conception of how nature and convention are intimately connected to each other through proper use in the practice of excellence in a way that foreshadows Aristotle. Repositioning Thucydides in the tradition of classical political thought as a predecessor of Aristotle rather than a follower of the sophists has important implications for both theorists and practitioners of world politics. Well aware of the importance of both nature and convention for the practice of excellence, Thucydides recognizes the importance of power politics as well as institutions in human affairs, and yet endorses neither uncritically. He develops a distinctively normative theory of world politics by placing proper use and moral judgement at the centre of his account. As such, the primary message Thucydides gives, to theorists and practitioners alike, is to deplore human suffering and to struggle towards moderation and practical wisdom in politics, making the best use of tendencies in human nature as well as available institutions to that end.
Forum: Transforming political community: a response to the critics
Authors: LINKLATER ANDREW
Published: July 2002

My first task is to thank the editors for creating a forum in which four authors from very different branches of social and political theory discuss my recent book on the transformation of political community. I am no less indebted to the authors involved for their participation in this debate. I hope this short reply does justice to their insightful comments and searching criticisms.

Randall L. Schweller is most sharply at odds with my position and I begin by responding to his criticisms. I then turn to the comments made by R. B. J. Walker and Jean Bethke Elshtain who subscribe to the critical project, broadly conceived, though not to my version of it. This essay ends with some responses to Norman Geras who shares my commitment to building on the Kantian and Marxian tradition but who has a rather different method of taking it further.
Rayleigh–Taylor instability analysis of targets with
a low-density ablation layer
Authors: SANZ J. , BETTI R. , GONCHAROV V.N.
Published: July 2002

Irregularities on the outer surface of Inertial
Confinement Fusion (ICF) capsules accelerated by laser
irradiation are amplified by the Rayleigh–Taylor
instability (RTI), which occurs at the ablation front (ablative
RTI), where density gradient and acceleration have the
same direction. The analytic stability theory of subsonic
ablation fronts, for Froude number larger than one, shows
that the main stabilization mechanisms are blowoff convection
(rocket effect equilibrating the gravity force) and ablation
(Sanz 1994; Betti et al. 1996). Blowoff convection
and ablation are enhanced if the ablator material is mixed
with high-Z dopants. The latest enhances radiation
emission setting the ablator on a higher adiabat, lowering
its density, and increasing the ablation velocity. When
such an ablator is used to push a solid deuterium-tritium
(D–T) shell, the D–T-ablator interface becomes
classically unstable. The aim of this paper is to investigate
the stability of such a configuration, represented by a
low-density ablator pushing a heavier shell, and study
the interplay between the classical and ablative RTIs occurring
simultaneously. The stability analysis is carried out using
a sharp boundary model (Piriz et al. 1997), which
contains all the basic physics of the RTI in ICF.
ROLLMOBS, a new drive system for omnimobile robots
Authors: Ferrière L. , Campion G. , Raucent B.
Published: July 2002

Typical mobile robot structures (e.g. wheelchairs or car-like robots) do not have the required mobility for common applications such as displacement in an office, hospital, workshop, etc. New structures based on the “universal wheel” (i.e. a wheel equipped with freely rotating rollers) have been developed to increase mobility. However, these structures have important drawbacks such as spurious vibrations and limited load capacity. This paper presents a new type of omnimobile platform using an original combination of spherical wheel and universal wheel. This structure will improve the robot
capabilities, i.e., load capacity and surmountable bumps.
An inverse position analysis of five-bar planar parallel manipulators
Authors: Alici Gürsel
Published: July 2002

In this paper, we present a simple method to obtain joint inputs needed to attain any point in the reachable workspace of a class of five-bar planar parallel manipulators which are based on five rigid links and five single degree of freedom joints – revolute and prismatic joints. Depending on the topology of the manipulators, two
mathematical expressions describing the path traced by the tip of two links connected to each other are obtained and solved simultaneously in order to determine the intersection points of the two paths which are the Cartesian coordinates of the connection points for the links. For the class of manipulators considered in this study, one of the links is the link
activated by an actuator fixed to the ground. So, rotational and/or translational joint inputs can be determined from the Cartesian coordinates of the tip of the activated links. Sylvester's dialytic elimination method is employed to solve the equations. Such a
methodology is easy to implement, computationally efficient and sound to compute all possible solutions. A numerical example is provided for each manipulator and the inverse position solutions are verified by substituting them into forward position equations. It is concluded that the proposed method is useful in trajectory planning and control of five-bar planar parallel manipulators in joint space.
Introduction to Section B of the special issue: languages and software in robotics
Authors: Rose J. A.
Published: July 2002

Section B of the special issue contains four papers dealing with diverse topics, viz. rehabilitation robotics applications, a software package for an automatic symbolic modelling of robots, the use of symplectic geometry, and the treatment of the Distributed Manipulation Environment method. This completes the wide review of various techniques and theoretical approaches aiming at solving the difficult problems of conventional robotics in the real world.
Using a new GA-based multiobjective optimization technique for the design of robot arms
Authors: Coello Coello Carlos A. , Christiansen Alan D. , Aguirre Arturo Hernández
Published: July 2002

This paper presents a hybrid approach to optimize the counterweight balancing of
a robot arm. A new technique that combines an artificial intelligence technique called the genetic algorithm (GA) and the weighted min-max multiobjective optimization method is proposed. These techniques are included in a system developed by the authors, called MOSES, which is intended to be used as a tool for engineering design optimization. The results presented here show how the new proposed technique can get better trade-off solutions and a more accurate Pareto front for this highly non-convex problem using an ad-hoc floating point representation and traditional genetic operators. Finally, a methodology to compute the ideal vector using a genetic algorithm is presented. It is shown how with a very simple dynamic approach to adjust the parameters of the GA, it is possible to obtain better results than those previously reported in the literature for this problem.
Control of nonholonomic mechanical systems using reduction and adaptation
Authors: Colbaugh R. , Barany E. , Trabatti M.
Published: July 2002

This paper considers the problem of controlling the motion of
nonholonomic mechanical systems in the presence of uncertainty regarding the
system model and state. It is proposed that a simple
and effective solution to this problem can be obtained by
first using a reduction procedure to obtain a lower dimensional
system which retains the mechanical system structure of the original
system, and then adaptively controlling the reduced system in such
a way that the complete system is driven to the
goal configuration. This approach is shown to be easy to
implement and to ensure accurate motion control despite measurement and
model uncertainty. The efficacy of the proposed control strategy is
illustrated through computer simulations and preliminary hardware experiments with nonholonomic
mechanical systems arising from both explicit kinematic constraints and symmetries
of the system dynamics.
Kinematic state estimation for a Mars rover
Authors: Balaram J. (Bob)
Published: July 2002

The Jet Propulsion Laboratory (JPL) is embarking on a series of exploration missions to Mars. Long-range rovers with several science instruments on board will traverse many kilometers on the surface. This paper describes some of the research underway at JPL as they pertain to navigation of these long-range rovers. A brief description is provided of the Sojourner rover which recently completed a short-range, near-lander Mars mission. A research rover called Rocky-7 under development at JPL implements a number of new technologies for long-range Mars traverses. The kinematic configuration of this vehicle is described as is tile sensor set. The paper then focuses on state estimation techniques used
on-board Rocky-7. A brief review of rover-related state-estimation work is presented and an Extended Kalman Filter framework is introduced. This includes process models for translation, small-angle/quaternion based rotations, gyro bias and wheel contact as well as observation models for a gyro, sun-sensor, and accelerometer. A novel slip constraint technique is developed to allow incorporation into the filter of the highly non-linear kinematics resulting from the rover's rocker-bogey suspension mechanism and
wheel-to-ground contact point variations. Simulation results are discussed to allow
detailed comparisons with ground-truth data and experimental results from Rocky-7
are presented.
The tables turned: Wilt Chamberlain versus Robert Nozick on rectification
Authors: Tebble Adam James
Published: July 2002

Recently the demand for rectification of past injustices has become an increasingly important issue. Each of the last three decades has witnessed democratization processes in the Mediterranean basin, Latin America, in Central and Eastern Europe and in Africa where debates have arisen over rectification of past wrongs which naturally include the unjust expropriation of property. Most recently, moreover, the idea of land restitution to indigenous people, particularly in Australia, Canada and Zimbabwe, has become a prominent, if not always equanimous, part of those countries' domestic political agendas. The difficulties associated with satisfying such demands have been discussed with particular regard to the framing of new post-Communist constitutions in eastern and central Europe by, among others, Jon Elster and Claus Offe. Yet, not only in the field of public policy has the issue of rectification become important. Perhaps because of these developments, there has been a resurgence of interest in rectification in political philosophy as is shown by a forthcoming collection of essays on the subject edited by Elster.
Causes of disease and causes of death
Authors: CARTER K. CODELL
Published: July 2002

In early-nineteenth-century medical literature, one finds an elegant symmetry between causes of disease and causes of death: both were sufficient causes of particular events. However, as I will argue, by the end of the century physicians no longer sought sufficient causes of individual disease episodes – instead almost all of medical research was organized around the quest for necessary causes that were shared by all the episodes of each particular disease. Such causes carried great practical and theoretical advantages: they enabled physicians to control and to explain disease phenomena.

One might wonder why there has been no parallel change in our thinking about causes of death; to this very day, causes
of death are sufficient causes of particular events. In principle there is no apparent reason why we could not identify necessary causes for classes of deaths – indeed, we sometimes do so. But, in the case of death, such causes hold little interest. Because of how they are used, sufficient causes for individual deaths are more interesting and more important to us than are necessary causes of deaths. Thus, the change in thinking about causes of disease – the change that destroyed the symmetry between causes of disease and causes of death – may not reflect simply progress within a fixed system of medical goals and values, but a profound change in the social role of physicians.
The Third International Workshop on Rules in Database Systems (RIDS'97)
Authors: GEPPERT ANDREAS , BERNDTSSON MIKAEL
Published: July 2002

This report is a summary of the Third International Workshop on Rules in Database Systems (RIDS'97) (Geppert & Berndtsson, 1997) which was organized by the database groups at University of Zurich (Switzerland) and University of Skövde (Sweden), and was held at the University of Skövde, June 26–28 1997. Following the success of RIDS '93 (Edinburgh) (Paton & Williams, 1993) (1st International Workshop on Rules in Database Systems), and RIDS '95 (Athens) (Sellis, 1995), the successor RIDS '97 brought together researchers working on both theoretical and practical aspects of rules in database systems.
THE ROBUSTNESS OF CRITICAL PERIOD EFFECTS IN SECOND LANGUAGE
ACQUISITION
Authors: DeKeyser Robert M.
Published: July 2002

This study was designed to test the Fundamental Difference Hypothesis (Bley-Vroman,
1988), which states that, whereas children are known to learn language almost completely
through (implicit) domain-specific mechanisms, adults have largely lost the ability to learn a
language without reflecting on its structure and have to use alternative mechanisms, drawing
especially on their problem-solving capacities, to learn a second language. The hypothesis
implies that only adults with a high level of verbal analytical ability will reach near-native
competence in their second language, but that this ability will not be a significant predictor of
success for childhood second language acquisition. A study with 57 adult Hungarian-speaking
immigrants confirmed the hypothesis in the sense that very few adult immigrants scored within
the range of child arrivals on a grammaticality judgment test, and that the few who did had high
levels of verbal analytical ability; this ability was not a significant predictor for childhood
arrivals. This study replicates the findings of Johnson and Newport (1989) and provides an
explanation for the apparent exceptions in their study. These findings lead to a
reconceptualization of the Critical Period Hypothesis: If the scope of this hypothesis is limited to
implicit learning mechanisms, then it appears that there may be no exceptions to the age effects
that the hypothesis seeks to explain.
INTRODUCING LANGUAGE AWARENESS.Leo van Lier.
London: Penguin, 1995. Pp. xii + 161.
Authors: Nation I. S. P.
Published: July 2002

This book is one in a series aimed at introducing teachers with little background in
linguistics and applied linguistics to a range of language-related issues. Other books in the series
include Introducing Applied Linguistics, Introducing Discourse Analysis, and
Introducing Listening. This book by van Lier has the goal of developing “an
understanding of the human faculty of language and its role in thinking, learning and social
life” (p. xi). Chapter 2, “The Building Blocks of Language,” briefly
introduces readers to the phonetic alphabet, assimilation, intonation, morphemes, and syntax.
Readers of SSLA (who are not the intended audience) will find, because of its
introductory nature, that it does not take them far in their knowledge of language awareness.
Teachers new to applied linguistics will find it very accessible and easy to read.
ACADEMIC WORDS AND GENDER
Authors: Scarcella Robin , Zimmerman Cheryl
Published: July 2002

This paper seeks to resolve certain questions pertaining to the
relationship between gender and second language vocabulary knowledge. One question we
examine is whether female and male ESL students at the University of California at Irvine
differ significantly in their knowledge of academic vocabulary in English as measured by
scores on the Test of Academic Lexicon (TAL). One hundred ninety-two freshman university
ESL students participated in the study. A t test, used to investigate differences in the
TAL scores of males and females, reveals that the males performed better on the TAL than the
females (t = 3.32, p = .001). Analyses of covariance were used to examine
questions pertaining to the effect of gender on the TAL, controlling for the possible effects of
the students' verbal Scholastic Aptitude Test (SAT) scores, length of residence in the
United States, and age of arrival in the United States. In all cases, gender remains
significantly related to the results of the TAL when controlling for the other variable: for
verbal SAT scores, F(1,181) = 5.86, p < .05; for length of residence,
F(1,187) = 9.64, p < .01; and for age of arrival in the United States,
F(1,185) = 10.22, p < .005. Neither the present study nor the gender
literature reviewed suggests that gender itself causes differences in the TAL scores.
In analyzing the results, we consider possible explanations for the males' better TAL
scores related to reading habits, interactional styles, educational backgrounds, and
cultures.
Shared attention and grammatical development in
typical children and children with autism
Authors: ROSENTHAL ROLLINS PAMELA , SNOW CATHERINE E.
Published: July 2002

The two studies presented here explore the relationship between

children's pragmatic skills and their growth in grammar. In study
1,
thirty normally developing children were videotaped interacting with
their parents at 1;2 and again at 2;7. Using correlational and regression

techniques, we found that pragmatic accomplishments of MUTUAL ATTENTION, as well as mother's conversational style, explained
45% of
the variance in grammar at 2;7. The second study investigated
pragmatic–grammatical relationships with data from 6 high-functioning

children with autism. To control for individual variation in skill level
at
the start of the study, within-individual growth rates for grammar were

estimated as our outcome. The results substantiated those of study 1, in

that pragmatic accomplishments within mutual attention predicted the
per month growth rate in grammar. We interpret these findings as
consistent with the position that the infant's social-pragmatic skills

contribute to the acquisition of grammar.
Construction of exceptional covers of generic groups
Authors: SULEIMAN IBRAHIM A. I. , WILSON ROBERT A.
Published: July 2002

We describe the construction of explicit representations of some
of the exceptional
covers of generic groups, that is, covers whose existence is not explained
by the
general theory of such groups.
Building Bridges: Life on Dunbar's Arbor, Past and Present
Authors: Aston Elaine , Reinelt Janelle
Published: July 2002

Rita, Sue and Bob Too by Andrea Dunbar and A State Affair, by Robin Soans. Co-production Out of Joint, Liverpool Everyman and Playhouse, and Soho Theatre Company. Double bill first performed at Liverpool Everyman on 19 October 2000 and Soho Theatre, London on 5 December 2000.
Designing Integrity into Position Estimation
Authors: Ober P. B.
Published: July 2002

While position integrity is crucial when positioning systems are to be used for safety-critical
operations such as in aviation applications, current positioning algorithms are generally
optimised for accuracy instead. Even when they are combined with fault detection and
exclusion schemes, these algorithms still give sub-optimal integrity. This paper promotes a
new method of algorithm design that takes integrity rather than accuracy as the parameter
to optimise. The new class of high-integrity positioning algorithms described aims to
improve integrity with both current and new systems not by improving the physical
infrastructure, but by using clever algorithmic optimisation in the receiver. A small
simulation example shows that the integrity and availability of un-augmented GPS for non-precision approach can indeed be improved substantially.
The Technical and Operational Feasibility of Automatic Number-Plate Recognition as the Primary Means for Road User Charging
Authors: Blythe P. T. , Knight Paul , Walker John
Published: July 2002

Following the publication of the Government's White Paper on Integrated Transport in July 1998, and a shift in emphasis by Local Authorities away from road building to demand management techniques, the current trend is to a more balanced approach, whereby the use of road-space may be charged to vehicle drivers, i.e. road users pay to use (at least some) roads, just as public transport passengers pay each time they travel. Key to this is the introduction of some form of road user charging or vehicle access control. In urban areas, this may be achieved using paper licences (as in Singapore, 1975–1998), electronic (microwave) tags and transponders (as in Trondheim and Oslo, Norway and in Singapore since 1998) or by the use of automatic video-based licence-plate recognition (ALPR). The use of video-based registration to check whether a vehicle has purchased (or been granted) some form of licence rights to use a particular road or cordoned area on a particular day seems both logical and attractive. However, this form of urban road use pricing has not been operated in anything other than small-scale pilot schemes, and there are a significant number of technical, organisational and operational issues that need to be researched before such a system could safely be implemented for everyday use. This paper is specifically aimed at addressing such key issues, to determine whether in the short term (next 5 years) ALPR could deliver a practical tool for use by local authorities, whether in isolation or as part of a package of applications, to reduce traffic congestion within urban areas.
In-vehicle Traffic Information Systems in Europe: Never Mind the (Band)Width, Feel the Quality
Authors: Calafell Jordi , Pyne Martin
Published: July 2002

The ever-increasing number of vehicles on the road has created a serious demand for traffic information not only on the move but also at the planning stage of a journey. While on the move, the driver will be able to re-route his/her journey avoiding traffic congestion, but this information could be even more valuable before starting the journey. Today there are differences between the three main ITS markets (USA, Japan and Europe). Japan is leading the way, with the introduction in 1995 of the Vehicle Information Communication System (VICS), which is a free service. Vehicles are equipped with VICS receivers taking information from a network of road beacons installed on main roads, transmitting traffic flows by infrared rays, wave beacons, and FM multiplex broadcast. Europe has been involved in driver information systems from the early '90s when RDS was developed, which is another free service, and most of the car radios sold in Europe are able to process RDS signals. Since then, new free services have been developed – for example, RDS-TMC. In the UK, the private sector has been heavily involved recently, its major player being Trafficmaster. The Trafficmaster system is based on a network of traffic detection sensors, which covers all major UK motorways and most of the major A roads, with plans to expand into the continent. Trafficmaster collects road traffic flows and disseminates this information to its subscribers via a range of technologies, including GSM. The quality of the information supplied by the free and subscription services can be improved by being fully integrated with on-board navigation systems and by providing more detailed and wider types of information. All current methods are described/analysed and compared in this paper, with future enhancement highlighted. One of the main limitations lies in current data transmission routes, which are not fast enough to support the data required for an optimal use of the system. Some technologies available will potentially allow the many service providers to transmit information.
Specifications for Reflectors and Radar Target Enhancers to Aid Detection of Small Marine Radar Targets
Authors: Briggs J. N.
Published: July 2002

This paper considers the need for better detectability of small targets at sea using marine radars in the 3 and 9 GHz bands. The problems of using radar reflectors and radar target enhancers to improve radar cross section, particularly when clutter is present, are discussed in detail. The IMO carriage requirement and the lack of suitably robust specifications are highlighted, and a proposal is made for a standard family of radar reflectors to meet the requirement. Radar target enhancers are also considered together with how these and radar reflectors should be mounted for best effect.
A long-term record of human impacts on an urban ecosystem in the sediments of Töölönlahti Bay in Helsinki, Finland
Authors: TIKKANEN MATTI , KORHOLA ATTE , SEPPÄ HEIKKI , VIRKANEN JUHANI
Published: July 2002

Ecological impacts of urbanization are receiving increasing scientific attention, yet few data sets permit long-term effects on terrestrial and aquatic ecosystems to be assessed. Töölönlahti Bay, in the centre of Helsinki, Finland, provided on opportunity to characterize recent human impacts especially by means of chemical and biostratigraphical analyses of a sediment core. Periods of coniferous forest, forest clearance, urbanization and the development of parks, can be distinguished in the pollen record of the core. Palynological diversity was highest before the forest clearance at the turn of the century. The character of the sediment and the water have changed substantially in response to rapid population growth, the construction of sewage systems and building within the catchment of the bay. This is reflected in marked increases in organic matter, phosphorus and heavy metal (Cd, Cu, Ni, Zn and Pb) concentrations between 1890 and 1960, accompanied by a rapid increase in diatom species indicative of eutrophication and a decline in diatom species diversity.

Since the cessation of waste-water disposal in the 1960s, concentrations of a number of pollutants have declined and water quality has gradually improved, but conditions are still affected by internal and atmospheric loadings. As a consequence of land uplift (2 mm per year) and the rapid sedimentation rate (6 mm per year), the volume of the bay is decreasing. Within 200 years, the shallow bay, which is skirted by extensive parks and famous cultural buildings such as the Finlandia and the Opera Houses, will fill with sediment unless it is dredged.
Molecular analysis of foot-and-mouth disease type O viruses

isolated in Saudi Arabia between 1983 and 1995
Authors: SAMUEL A. R. , KNOWLES N. J. , KITCHING R. P. , HAFEZ S. M.
Published: July 2002

Partial nucleotide sequence of the capsid polypeptide coding gene

1D (VP1) was determined for

68 serotype O foot-and-mouth disease viruses isolated between 1983 and
1995

from outbreaks

occurring in Saudi Arabia. The sequences were compared with previously

published sequences:

14 viruses of Middle Eastern origin (isolated between 1987 and 1991); and

with four vaccine virus strain sequences, three originating from the Middle
East

(O1/Turkey/Manisa/69,

O1/Sharquia/Egypt/72 and

O1/Israel/2/85) and

one from Europe (O1/BFS 1860/UK/67). The

virus isolates from Saudi Arabia and the Middle East vaccine virus strains

formed a related

genetic group distinct from the European O1virus. Within this

large group 12 distinct genetic sublineages were observed.
The rate of CD4 decline as a determinant of progression to
AIDS independent of the most recent CD4 count
Authors: LEPRI A. COZZI , SABIN C. A. , PHILLIPS A. N. , LEE C. A. , PEZZOTTI P. , REZZA G. , THE ITALIAN SEROCONVERSION STUDY
Published: July 2002

The data of two cohort studies of HIV-infected individuals
were used to examine whether the
rate of CD4 decline is a determinant of HIV progression, independent of
the most recent CD4
count. Time from seroconversion to clinical AIDS was the main outcome measure.
Rates of
CD4 decline were estimated using the ordinary least squares regression
method. AIDS
incidences were compared in individuals who had previously experienced
either a steeper or a
less steep rate of CD4 decline. Cox proportional hazards model including
a time-dependent
covariate for the rate of CD4 decline was performed. The rate of prior
CD4 decline was
significantly associated with the risk of developing AIDS independently
from the most recent
CD4 count, with a 2% increase in hazard of AIDS (P<·01)

for a difference of 10 cells/mm3 in the estimated yearly
drop
in CD4 count. This finding gives scientific credit to the belief that
individuals with a prior steeper CD4 decline consistently have a higher
subsequent risk of
developing AIDS than those with a less steep prior decline.
An international outbreak of Salmonella enteritidis associated
with lasagne; lessons on the need for cross-national
co-operation in investigating food-borne outbreaks
Authors: NYLEN G. , FIELDER H. M. P. , PALMER S. R.
Published: July 2002

We investigated an outbreak of Salmonella enteritidis involving at least 19 British tourists
returning from one hotel in another European country. A retrospective cohort study of 47
hotel guests identified lasagne as the most likely vehicle of transmission (RR 11·5; 95% CI
3·0–44·1; P<0·0001). However, difficulties in information exchange and lack of formal
mechanisms to agree on the aims of the cross-national investigation hampered efficient
management of the outbreak. The factors leading to contamination of the food vehicle were
not identified and therefore specific action to prevent reoccurrence could not be taken. There is
need to develop protocols for cross-national investigations of outbreaks in Europe which
should include specifying objectives, roles and responsibilities of investigators and control
agencies, with formal reporting of the outcome of the investigation.
Completing the molecular investigation into the HIV outbreak
at Glenochil prison
Authors: YIRRELL D. L. , HUTCHINSON S. J. , GRIFFIN M. , GORE S. M. , LEIGH-BROWN A. J. , GOLDBERG D. J.
Published: July 2002

In a molecular investigation into the outbreak of HIV in Glenochil during the first 6 months
of 1993, we previously demonstrated that 13 out of the 14 HIV positive inmates were infected
with a virtually identical strain, and discounted 2 others as potential sources. Here we
investigate a further 8 potential contacts and 4 potential sources which were identified in the
companion paper [1]. We were able to examine viral sequence from all but one of these 12
and results have revealed them to be distinct both from each other and the original 14. Thus,
despite an intensive follow-up investigation, we have been unable to identify any further HIV
infections that might have been part of the 1993 outbreak. It is possible that persons who were
infected at that time remain undetected; however this and the companion report strongly
suggest that if this were the case the likely numbers would be few.
The marsupial and monotreme thymus, revisited
Authors: Haynes Julie Irene
Published: July 2002

The anatomy and histology of the thymus in monotremes and marsupials were revisited and several new observations made. Tissues of the mediastinum and/or ventral neck of 134 animals altogether (12 Australian marsupial and monotreme species) were examined and the locations of thymic tissues documented. Descriptions not previously recorded include the gross anatomy of the thymus in monotremes, the bandicoot (Isoodon macrourus, Isoodon obesulus), the wombat (Lasiorhinus latifrons), and koala (Phascolarctos cinereus), as well as light and electron microscopic features in all species examined. In monotremes, thymic tissue was diffusely spread in the mediastinum and extended over the ventral surface of the pericardium. In the bandicoot, a small, deep cervical thymus was persistently present as well as the expected thoracic thymus and contrary to previous observations, a thoracic thymus was found in the wombat but not the koala. Both species also have a cervical thymus. In the marsupial species examined, additional thymic tissue was often present in the vicinity of the carotid bifurcations, in the deep ventral regions of the neck. In many animals, thymic tissue of deep cervical origin as well as thoracic thymus was mingled with parathyroid tissue. In several specimens, the two tissue types lacked intervening connective tissue barriers and at the electron microscopic level, attenuated processes of epithelial reticular cells were the only tissue components separating parathyroid and thymic tissues. The role of the cervical thymus in diprotodont marsupials remains to be elucidated. The presence of aberrant thymic tissue in marsupials is important in the interpretation of experiments involving thymectomy and immunological development because complete removal of thymic tissue may not occur. One aspect that has received little attention is the function of the thymic epithelial reticular cells in marsupial development and a suggestion is made that perhaps the extra thymic tissue found in marsupials provides extra epithelial reticular cells necessary for the production of cytokines and other secretions to sustain the development of immunological competence.
Censusing and monitoring black rhino (Diceros bicornis) using an objective spoor (footprint) identification technique
Authors: Jewell Zoë C. , Alibhai Sky K. , Law Peter R.
Published: July 2002

An objective, non‐invasive technique was developed for identifying individual black rhino from their footprints (spoor). Digital images were taken of left hind spoor from tracks (spoor pathways) of 15 known black rhino in Hwange National Park, Zimbabwe. Thirteen landmark points were manually placed on the spoor image and from them, using customized software, a total of 77 measurements (lengths and angles) were generated. These were subjected to discriminant and canonical analyses. Discriminant analysis of spoor measurements from all 15 known animals, employing the 30 measurements with the highest F‐ratio values, gave very close agreement between assigned and predicted classification of spoor. For individual spoor, the accuracy of being assigned to the correct group varied from 87% to 95%. For individual tracks, the accuracy level was 88%. Canonical analyses were based on the centroid plot method, which does not require pre‐assigned grouping of spoor or tracks. The first two canonical variables were used to generate a centroid plot with 95% confidence ellipses in the test space. The presence or absence of overlap between the ellipses of track pairs allowed the classification of the tracks. Using a new ‘reference centroid value’ technique, the level of accuracy was high (94%) when individual tracks were compared against whole sets (total number of spoor for each rhino) but low (35%) when tracks were compared against each other. Since tracks with fewer spoor were more likely to be misclassified, track sizes were then artificially increased by summing smaller tracks for the same rhino. The modified tracks in a pairwise comparison gave an accuracy of 93%. The advantages, limitations and practical applications of the spoor identification technique are discussed in relation to censusing and monitoring black rhino populations.
THE MANAGING EDITOR'S REPORT ON THE JOURNAL OF ZOOLOGY FOR 2000
Authors: Clutton‐Brock Juliet
Published: July 2002

The Editors decided, during the year, that there was really little need for a Short Communications Section and it would be more effective to incorporate short papers into the body of the Journal. Great thanks therefore go to Martyn Gorman for his many years as Editor of the Communications from the Mammal Society and latterly for his editing of the Short Communications.

By the end of 2000, the majority of the members of the Editorial Board had completed a five year term and an editorial decision was taken to replace the Board with a small team of international Editorial Consultants who would be asked to act as ambassadors for the Journal as well as giving advice on editorial matters. I should therefore like to thank all the retiring members of the Editorial Board for their work on the Journal and welcome the new Editorial Consultants whose names are given on the inside front cover of this issue.

During 2000, 160 papers were published in the twelve monthly parts of volumes 250–252 and there was approximately eleven months between acceptance of a paper and its publication. Our aim is to reduce this time to a maximum of ten months from now on.

Over the year, 286 manuscripts were submitted to the Journal and reports were written on them by 471 referees, whose names are listed below. As in previous years, I should like to make full acknowledgement of the generosity of these referees in both their time and expertise, without which the Journal could not survive. I should also like to thank all the authors who have sent in colour slides for possible reproduction on the covers.
A review of the comparative morphology and systematics of Utah Lake suckers (Catostomidae)
Authors: Cook A. Gaylon
Published: July 2002

Utah Lake, Utah, U.S.A. harbours an endemic catostomid fish, the June sucker Chasmistes liorus, that is recognized as being endangered. Since 1981, post‐1935 representatives of the June sucker have generally been considered to be examples of a self‐propagating hybrid. Utah Lake has contained another endemic catostomid, the webug sucker Chasmistes fecundus that was regarded as a true species until 1981 when it was judged to be an extirpated sterile hybrid. Since then, fisheries biologists have not attempted to identify it. This review makes a comparative examination of the published descriptions of the internal and external anatomy of these two species, plus the third catostomid of Utah Lake, the Utah sucker Catostomus ardens. The Utah sucker purportedly crossed with a form of the June sucker that has supposedly since been expunged, to produce hybrids. On the basis of comparative morphology and the consideration of temporal changes in the habitat and piscifauna of Utah Lake, the authenticity of supposed hybridism in the webug sucker, and in the contemporary June sucker, is analysed. The conclusion is reached that there is insufficient evidence to deem these taxa hybrids, or the webug sucker, extinct.
Morphology and reproduction of Nipponomysella subtruncata (Yokoyama), a galeommatoidean bivalve commensal with the sipunculan Siphonosoma cumanense (Keferstein) in Japan
Authors: Lützen J. , Takahashi T. , Yamaguchi T.
Published: July 2002

The shell and anatomy of Nipponomysella subtruncata is described. The bivalve is attached singly or in groups of up to nine on Siphonosoma cumanense, a burrowing intertidal sipunculan in south‐west Japan. The species is a protandrous hermaphrodite. Specimens 1.4–2.5 mm long are males, which between 2.1 and 3 mm in length reverse sex and remain females. Reproduction peaks in summer and the annual number of clutches is small. Ripe oocytes, 84–88 μm diameter, are spawned into the suprabranchial cavity where they develop into 107‐μm‐long straight‐hinged veligers. Following a planktotrophic period of unknown duration, the c. 360‐μm‐long spat normally settle upon and attach to the shells of larger, predominantly female, individuals. At a length of 1–1.6 mm they detach again and live separately thereafter. Sperm are transferred in spermatophores and stored within paired, mushroom‐shaped receptacles located posteriorly in the female's suprabranchial cavity. The receptacles first appear in large males or in specimens in the process of reversing sex. Stored sperm probably survive long enough to fertilize more than one clutch. The anatomy of Nipponomysella is characteristic of the Montacutidae, and is of especial interest because of the unique structure of the sperm receptacles.
Birds of paradise (Paradisaeidae) and bowerbirds (Ptilonorhynchidae): regional levels of biodiversity and terrane tectonics in New Guinea
Authors: Heads Michael
Published: July 2002

Most species of birds of paradise (Paradisaeidae) are endemic in the rainforests of New Guinea. There are also a few species in the northern Moluccas and in northern Australia. Bowerbirds (Ptilonorhynchidae) are centred in New Guinea but are more widespread in Australia. The two families have often been regarded as sister groups, but in recent studies Paradisaeidae appear as sister to Corvidae, a worldwide family which is notably depauperate in New Guinea and Australia. This indicates vicariance of a worldwide ancestor, rather than invasion of New Guinea. Other families in the superfamily Corvoidea include Ptilonorhynchidae (basal), Campephagidae (Africa to New Guinea and Fiji), and Cracticidae (Australia to New Guinea). Biodiversity levels in Paradisaeidae and Ptilonorhynchidae were assessed from literature records by counting numbers of species in grid cells 1° latitude by 1° longitude. Birds of paradise are equally diverse in the Mendi square and the Mount Hagen–Wahgi Valley–Jimi Valley square. Bowerbirds are most diverse in the Mount Hagen–Wahgi Valley–Jimi Valley square. This area lies on one of the main tectonic boundaries in New Guinea, the former margin of the Australian craton, and is geologically distinctive in having several diverse accreted terranes juxtaposed there, including an ophiolite complex. It also includes the western slopes of Mount Wilhelm, one of the highest mountains in the New Guinea orogen. Paradisaeidae have secondary centres of diversity in the southern part of the New Guinea orogen (south of the former craton margin), while Ptilonorhynchidae have secondary centres north of the craton margin on the accreted terranes, and also in eastern Australia. Within New Guinea the two distributions correlate closely with the geological interpretation of the orogen as comprising southern (craton) and northern (accreted terrane) components. Within Australia, Paradisaeidae have two species per degree square in northern Cape York Peninsula (on the old Australian craton), and only one elsewhere in eastern Australia, whereas Ptilonorhynchidae have a clear Australian massing further south in Queensland, on the accreted terranes of the Tasman orogen.
Social context in
developmental psychopathology: Recommendations for future research from the MacArthur
Network on Psychopathology and Development
Authors: BOYCE W. THOMAS , FRANK ELLEN , JENSEN PETER S. , KESSLER RONALD C. , NELSON CHARLES A. , STEINBERG LAURENCE ,   THE
MACARTHUR FOUNDATION RESEARCH NETWORK ON PSYCHOPATHOLOGY AND
DEVELOPMENT
Published: July 2002

Accumulating evidence suggests that social contexts in early life have important and
complex
effects on childhood psychopathology. Spurred by the lack of an explicit operational definition
that could guide the study of such effects, we define a social context operationally as “a
set of interpersonal conditions, relevant to a particular behavior or disorder and external to, but
shaped and interpreted by, the individual child.” Building on this definition, we offer a
series of recommendations for future research, based on five theoretically derived propositions:
(a) Contexts are nested and multidimensional; (b) contexts broaden, differentiate, and deepen
with age, becoming more specific in their effects; (c) contexts and children are mutually
determining; (d) a context's meaning to the child determines its effects on the child and
arises from the context's ability to provide for fundamental needs; and (e) contexts should
be selected for assessment in light of specific questions or outcomes. As reflected in an
increasingly rich legacy of literature on child development and psychopathology, social contexts
appear to influence emerging mental disorders through dynamic, bidirectional interactions with
individual children. Future research will benefit from examining not only statistical interactions
between child- and context-specific factors, but also the actual transactions between
children and contexts and the transduction of contextual influences into pathways of
biological mediation. Because adverse contexts exert powerful effects on the mental health of
children, it is important for the field to generate new, more theoretically grounded research
addressing the contextual determinants of psychological well-being and disorder.
Kramers' problem for a variable collision frequency model
Authors: SIEWERT C. E.
Published: July 2002

The often-studied problem known as Kramers' problem, in the general area of rarefied-gas
dynamics, is investigated in terms of a linearized, variable collision frequency model of
the Boltzmann equation. A convenient change of variables is used to reduce the general
case considered to a canonical form that is well suited for analysis by analytical and/or
numerical methods. While the general formulation developed is valid for an unspecified
collision frequency, a recently developed version of the discrete-ordinates method is used
to compute the viscous-slip coefficient and the velocity defect in the Knudsen layer for
three specific cases: the classical BGK model, the Williams model (the collision frequency is
proportional to the magnitude of the velocity) and the rigid-sphere model.
The influence of material non-uniformity

preceding shear-band formation in a model for granular flow
Authors: SCHAEFFER DAVID G. , SHEARER MICHAEL
Published: July 2002

The onset of shear-banding in a deforming elastoplastic solid

has been linked to change of type

of the governing partial differential equations. If uniform material properties

are assumed, then

(i) deformations prior to shear-banding are uniform, and (ii) the onset
of

shear-banding occurs

simultaneously at all points in the sample. In this paper we study, in
the

context of a model for

anti-plane shearing of a granular material, the effect of a small variation
in

material properties

(e.g. in yield strength) within the sample. Using matched asymptotic expansions,

we find that

(i) the deformation is extremely non-uniform in a short time period

immediately preceding the

formation of shear-bands; and (ii) generically, a shear-band forms at a

single location in the sample.
Ploughing flows
Authors: TUCK E. O. , VANDEN-BROECK J.-M.
Published: July 2002

A semi-infinite body, modelling the leading edge of
a cutting tool or submerged hydrofoil,
lies beneath a free surface in a uniform stream of infinitely-deep inviscid
incompressible
fluid flowing steadily under gravity. The body has horizontal upper and
lower surfaces. The
oncoming flow is partly diverted over, and partly under the body. The flow
in that portion that
travels over the body can be supercritical or subcritical. When
it is supercritical it approaches
a stream of some (to be determined) speed in a channel of some (to be determined)
depth.
When it is subcritical, there is also a train of waves on that stream,
whose amplitude is
also to be determined. Semi-analytic high-speed and low-speed solutions
are obtained, and a
numerical solution for finite speeds. There is a ‘forbidden’

intermediate speed range, within
which steady flow may not be possible.