bluuebunny/crossref_metadata_2025 huggingface dataset:
Discontinuity and variability in relational complexity: Cognitive and brain development
Authors: Coch Donna , Fischer Kurt W.
Published: July 2002

Relational complexity theory has important virtues, but
the present model omits key aspects and evidence. In contrast,
skill theory specifies (1) a detailed series of developmental changes
in relational complexity from birth to age 30, (2) processes of
interaction of content and structure that produce variability in
complexity, (3) the role of cortical development, and (4) empirical
criteria for complexity levels, including developmental
discontinuities. Many findings support these specifications.
The other hard problem: How to bridge the gap between symbolic and subsymbolic cognition
Authors: Cleeremans Axel
Published: July 2002

The constructivist notion that features are purely functional
is incompatible with the classical computational metaphor of mind. I
suggest that the discontent expressed by Schyns, Goldstone &
Thibaut about fixed-features theories of categorization reflects the
growing impact of connectionism. Their perspective is similar to
recent research on implicit learning, consciousness, and development.
A hard problem remains, however: how to bridge the gap between
subsymbolic and symbolic cognition.
Updates on axons in the rat corpus callosum
Authors: Juraska Janice M.
Published: July 2002

Developmental counts of axons in the splenium of the rat
corpus callosum are compatible with the hypothesis that estrogen
may be acting late in development to sculpt the female nervous
system.
Beyond substance concepts in cognitive development
Authors: Nelson Katherine
Published: July 2002

Millikan's theory of substance concepts has advantages
for psychological theories, including those in cognitive development.
However, the disadvantage is that it cannot be generalized even to
some of the most common concepts that children acquire in the early
years of life. For a general theory we must get beyond
substances.
A multiculture of veridicalities
Authors: van Brakel J.
Published: July 2002

Edelman's target article purports to be about veridical
representations. I argue that it would be a mistake to think it has
much to do with veridicality as normally understood.
Locus equation: Assumption and dependencies
Authors: Pastore Richard E. , Crawley Edward J.
Published: July 2002

Evaluating the current locus equation under ideal conditions
identifies important and unexpected parameter dependencies. Locus
equation (LE) utility, either as a valid laboratory tool or possible
invariant cue, depends on stringent specification of critical
parameters and rigorous empirical testing.
Aggressiveness and dominance
Authors: Mueller Ulrich
Published: July 2002

Aggressiveness is a vital component of dominating behavior. We
must distinguish adaptive from nonadaptive aggression and must control
for skills, intelligence, appropriate context variables, and –
most important – whether the aggression displayed was actually
suitable for improving a subject's social status. If we do, we
may find a consistent positive correlation between adaptive
aggressiveness and testosterone.
Biological neuroscience is only as radical as the evolution of mind
Authors: Blumenthal Terry , Schirillo James
Published: July 2002

A biological neuroscientific theory must acknowledge that the
function of a neurological system is to produce behaviors that promote
survival. Thus, unlike what Gold & Stoljar claim, function and
behavior are the province of neurobiology and cannot be relegated to
the field of psychological phenomena, which would then trivialize the
radical doctrine if accepted. One possible advantage of adopting such
a (correctly revised) radical doctrine is that it might ultimately
produce a successful, evolutionarily based, theory of mind.
Intrinsic changes in experience: Swift and enormous
Authors: Dennett Daniel C.
Published: July 2002

Because, as Palmer shows, the only kinds of differences that can be detected are differences in relational structure, and relational structure is precisely what is preserved by isomorphism, his own arguments can be used to expose the incoherent motivation behind the traditional idea of “intrinsic qualities” of experience.
Early effects of semantic meaning on electrical brain activity
Authors: Skrandies Wolfgang
Published: July 2002

When words are read, the visual cortex is activated,
independent of whether visual or motor associations are elicited.
This word-evoked brain activity is significantly influenced by
semantic meaning. Such effects occur very early after stimulus
presentation (at latencies between 80 and 130 msec), indicating
that semantic meaning activates different neuronal assemblies
in the human visual cortex when words are processed.
Exorcising the devil: Adding details to a descriptive account of oculomotor control
Authors: Zelinsky Gregory J.
Published: July 2002

Findlay & Walker give voice to several common lines of thought regarding oculomotor control but do not provide sufficient detail for a critical evaluation of their theory. I argue that arbitrary spatial and temporal saccade metrics can be produced simply by manipulating the initial activation values in their model – values that the authors never specify. This lack of detail makes it difficult to anticipate the model's specific oculomotor behavior, or to compare this behavior to models opting for a more quantitative framework.
Implicit versus explicit: An act-r learning perspective
Authors: Taatgen Niels A.
Published: July 2002

Dienes & Perner propose a theory of implicit and explicit
knowledge that is not entirely complete. It does not address many of the
empirical issues, nor does it explain the difference between implicit
and explicit learning. It does, however, provide a possible unified
explanation, as opposed to the more binary theories like the systems and
the processing theories of implicit and explicit memory. Furthermore, it
is consistent with a theory in which implicit learning is viewed as
based on the mechanisms of the cognitive architecture, and explicit
learning as strategies that exploit these mechanisms.
The empirical base of linguistics: Grammaticality judgments and linguistic
methodology. Carson T. Schütze. Chicago: University of Chicago Press, 1996. Pp.
212.
Authors: Durán Pilar
Published: July 2002

This book by Carson Schütze poses an important question. Are grammaticality
judgments a reliable source of data for linguistic theories? Grammaticality judgments, reliable or
not, have been the main, and most often the only, source of data in linguistic theory for many
years. “‘Because many of the relevant structures are fairly complex and simply
might not arise in the normal course of conversation, or during observation by an
experimenter' (White, 1989, p. 58), UG [Universal Grammar] researchers have
generally relied on some form of grammaticality judgment (GJ) task” (Katrien &
Lantolf, 1992, p. 32). Katrien and Lantolf (1992) pointed out that with this task linguists try to
draw on speakers' intuitions about their competence. Grammaticality judgments consist of
questions about whether a sentence is grammatical according to native speakers. Most often, the
native speaker is the linguist her- or himself as the only subject. Not only can bias exist when
linguists are the source of data for her or his own theories, but also relying on the intuitions of
only one speaker limits the credibility of the theory. When more than one speaker is queried, it
has been shown that consistency is not always guaranteed: variation among and within speakers
is a common feature in judgments (Mohan, 1977; Snow & Meijer, 1977). Idiosyncrasies of
the subjects, presentation of the material, and experimenter's procedure are among the
factors that contribute to this variation in judgments. An underlying problem in linguistic
theorizing comes from the fact that linguists are normally not “trained in methods for
getting reliable data” (p. 4). All this results in theories that are not adequately supported.
Nonetheless, they are used as a springboard for new theories. Schütze provides linguists
with answers to the following questions. What information about language can grammaticality
judgments offer? What factors affect the form of these judgments? What can be done to make the
best use of these judgments?
How the mind works. Steven Pinker. Allen Lane: W. W. Norton, 1998. Pp.
660.
Authors: Dickins Tom
Published: July 2002

Steven Pinker has written a very lengthy new book that, as the dust cover informs the reader,
attempts to do for the rest of the mind what he did for language in his 1994 bestseller, The
Language Instinct. What The Language Instinct did was to expand on Pinker
and Bloom's (1990) thesis that language is an evolved system, an intricately designed set
of mechanisms that must have been shaped by natural selection. What The Language
Instinct did not do was provide a specific thesis about how language actually evolved. That
Pinker did not provide a theory of actual language origins in his 1994 book is not a weakness.
Indeed, Pinker's work has provided a useful rubric for subsequent linguistic theorizing (cf.
Hurford, Studdert-Kennedy, & Knight, 1998). It is this directional strategy that also appears
to be at the heart of “how the mind works.” Critically, Pinker wants the reader to
think about three main ideas (see the interview with Pinker in The Evolutionist): (1)
computation; (2) evolution; and (3) specialization.
Stably ergodic approximation: two examples
Authors: SHUB MICHAEL , WILKINSON AMIE
Published: July 2002

It has been conjectured that the stably ergodic diffeomorphisms are open and dense in the space of volume-preserving, partially hyperbolic diffeomorphisms of a compact manifold. In this paper we deal with two recalcitrant examples; the standard map cross Anosov and the ergodic automorphisms of the 4-torus. In both cases we show that they may be approximated by stably ergodic diffeomorphisms which have the stable accessibility property.
On almost everywhere strong convergence of multi-dimensional continued fraction algorithms
Authors: HARDCASTLE D. M. , KHANIN K.
Published: July 2002

We describe a strategy which allows one to produce computer assisted proofs of almost everywhere strong convergence of Jacobi–Perron type algorithms in arbitrary dimension. Numerical work is carried out in dimension three to illustrate our method. To the best of our knowledge this is the first result on almost everywhere strong convergence in dimension greater than two.
Hyperbolic maps in p-adic dynamics
Authors: BENEDETTO ROBERT L.
Published: July 2002

In this paper we study the dynamics of a rational function \phi\in K(z) defined over some finite extension K of \mathbb{Q}_p. After proving some basic results, we define a notion of ‘components’ of the Fatou set, analogous to the topological components of a complex Fatou set. We define hyperbolic p-adic maps and, in our main theorem, characterize hyperbolicity by the location of the critical set. We use this theorem and our notion of components to state and prove an analogue of Sullivan's No Wandering Domains Theorem for hyperbolic maps.
Ratio ergodic theorems for maps
with indifferent fixed points
Authors: INOUE TOMOKI
Published: July 2002

We study one-dimensional transformations $T$ with indifferent fixed points
$p$ and $q$ ($p$ and $q$ are fixed points with $ T^{\prime}(p) =
T^{\prime}(q) = 1 $). In the case when $T$ has a Lebesgue equivalent infinite
invariant measure, we give the ratio ergodic theorems which describe the
limit value of the ratio of the sojourn time of the trajectory
$\{T^k(x)\}_{k=0}^n$ in a small neighborhood of $p$ to that in a small
neighborhood of $q$.
Rotation measures for homeomorphisms of the torus
homotopic to a Dehn twist
Authors: DOEFF H. ERIK
Published: July 2002

We extend the theory of rotation vectors to
homeomorphisms of the two-dimensional torus that are homotopic to a Dehn
twist. We define a one-dimensional rotation number and recreate the
theory of the homotopic case to the identity case. We prove that if such a
map is area preserving and has mean rotation number zero, then it must
have a fixed point. We prove that the rotation set is a compact
interval, and that if the rotation interval contains two distinct
numbers, then for any rational number in the rotation set there exists a
periodic point with that rotation number. Finally, we prove that any
interval with rational endpoints can be realized as the
rotation set of a map homotopic to a Dehn twist.
Are the dimensions of a set and its image equal under typical
smooth functions?
Authors: SAUER TIMOTHY D. , YORKE JAMES A.
Published: July 2002

We examine the question whether the dimension $D$ of a set
or probability measure is the same as the dimension of its
image under a typical smooth function, if the range space
is at least $D$-dimensional. If $\mu$ is a Borel
probability measure of bounded support in ${\Bbb R}^n$
with correlation dimension $D$, and if $m\geq D$, then
under almost every continuously differentiable function
(‘almost every’ in the sense of prevalence) from ${\Bbb
R}^n$ to ${\Bbb R}^m$, the correlation dimension of the
image of $\mu$ is also $D$. If $\mu$ is the invariant
measure of a dynamical system, the same is true for almost
every delay coordinate map. That is, if $m\geq D$, then
$m$ time delays are sufficient to find the correlation
dimension using a typical measurement function. Further,
it is shown that finite impulse response (FIR) filters do
not change the correlation dimension. Analogous theorems
hold for Hausdorff, pointwise, and information dimensions.
We show by example that the conclusion fails for
box-counting dimension.
Stability of the maximal measure
for piecewise monotonic interval maps
Authors: RAITH PETER
Published: July 2002

Let $T:X\to{\Bbb R}$ be a piecewise
monotonic map, where $X$ is a finite union of closed
intervals. Define $R(T)=\bigcap_{n=0}^{\infty}
\overline{T^{-n}X}$, and suppose that $(R(T),T)$ has
a unique maximal measure $\mu$. The influence of
small perturbations of $T$ on the maximal measure is
investigated. If $(R(T),T)$ has positive topological
entropy, and if a certain stability condition is
satisfied, then every piecewise monotonic map
$\tilde{T}$, which is contained in a sufficiently
small neighbourhood of $T$, has a unique maximal
measure $\tilde{\mu}$, and the map
$\tilde{T}\mapsto\tilde{\mu}$ is continuous
at $T$.
Periods of discretized linear Anosov maps
Authors: BEHRENDS EHRHARD , FIEDLER BERNOLD
Published: July 2002

Integer $m\times m$ matrices $A$ with determinant $1$ define diffeomorphisms of the $m$-dimensional torus $T^m=({\Bbb R}/{\Bbb Z})^m$ into itself. Likewise, they define bijective self-maps of the discretized tori $({\Bbb Z}/n{\Bbb Z})^m=({\Bbb z}_n)^m$. We present estimates of the surprisingly low order (or period) $\Per_A(n)$ of the iteration $A^r, r=1,2,3,\ldots,$ on the discretized torus $({\Bbb z}_n)^m$. We obtain $\Per_A(n)\leq 3n$ for dimension $m=2$. In the special case of the Anosov map $A={2\ 1 \atopwithdelims() 1\ 1}$, this result is due to Dyson and Talk [DT92]. For arbitrary dimensions $m>2$ we obtain $$\Per_A(n)\leq {\rm constant}\cdot n^{m-1},$$ provided $n$ is a power of a prime number. For general $n$, number theoretic problems arise.
Stable ergodicity of the time-one map of a geodesic flow
Authors: WILKINSON AMIE
Published: July 2002

We prove that the time-one map of the geodesic flow for a closed, negatively curved surface is stably ergodic.
A simple proof of the exponential convergence of the modified Jacobi–Perron algorithm
Authors: MEESTER RONALD
Published: July 2002

The modified Jacobi–Perron algorithm was shown by Ito etal in 1993 to be strongly convergent (in the sense of Brentjes 1981) almost everywhere with exponential rate. Their proof relies on very complicated computations. We will show that the original article by Podsypanin in 1977 on the modified Jacobi–Perron algorithm almost contains a proof of this convergence with exponential rate. The only ingredients missing in that article are some ergodic-theoretical facts about the transformation generating the approximations. This leads to a very simple proof of the before mentioned exponential convergence in the modified Jacobi–Perron algorithm.
Negotiations in Public-Policy Making: Exogenous Barriers to Successful Dispute Resolution
Authors: Holzinger Katharina
Published: July 2002

The number of public policy conflicts has increased sharply in most western democracies, especially in the fields of
planning, regional development, and environmental policy. Attempts have been made to find a way out through new
forms of negotiation-based conflict resolution. Alternative Dispute Resolution raises high expectations as to its potential
for reaching consensual solutions, to be achieved through extended participation, transparency, and procedural justice.
However, success or failure of negotiations do not depend only on the procedure, but also on factors exogenous to it.
The first section addresses the question: which exogenous factors affect the opportunities for an agreement in public
policy negotiations and how do they exert their influence? Spatial representation of bargaining is used as an analytical
framework. The second section shows how outside options, exogenous restrictions, and political directives for the
negotiators affected the negotiation space and the final outcome in a case of environmental mediation in Germany.
Reshaping Employment Regimes in Europe: Policy Shifts Alongside Boundary Change
Authors: Teague Paul
Published: July 2002

This paper surveys the direction of change to employment regimes in the EU, in which fiscal consolidation constitutes the macro-economic foundations to labour markets in virtually every member-state. Attempting to address budget deficits has had important spillover effects, most notably on the conduct of pay determination. In particular, multi-tier bargaining in Europe has been revived not to conclude the social corporatist deals of the past but to reorient labour market behaviour to the introduction of a single currency. Support systems for the unemployed are also experiencing wide-ranging reforms across the EU: governments are attempting to shift expenditure from passive measures to more direct initiatives to help people get back to work. The prospect for closer cross-national collaboration on labour market matters has increased by Brussels launching a programme to benchmark employment policies across the EU. Together, these changes are streamlining Social Europe and reorganising the sovereign boundaries of economic citizenship.
Engineering consent: the Carnegie Endowment for International Peace and the mobilization of American public opinion, 1939–1945
Authors: PARMARA INDERJEET
Published: July 2002

The role of private organizations and think tanks in the United States have been well documented. The Council on Foreign Relations in particular has been much discussed—less so, the Carnegie Endowment for International Peace. This article seeks to fill that gap by exploring its influence on American public opinion during World War II. Based upon archival research, the essay examines the background of the key members of the Endowment, their outlook and the impact their work had in shaping US attitudes. Using Gramsci's notion of an ‘historic bloc’ wedded to the insights of the ‘corporatist’ school of American foreign relations, the conclusion reached is that the organization—along with other key bodies situated at the interface between the private and public spheres—played a not inconsiderable part in educating Americans for internationalism before the end of the war and the onset of the Cold War two years later.
Particle physics with petawatt class lasers
Authors: KARSCH S. , HABS D. , SCHÄTZ T. , SCHRAMM U. , THIROLF P.G. , MEYER-TER-VEHN J. , PUKHOV A.
Published: July 2002

With a Petawatt class CPA laser of the LLNL Livermore
or the proposed GSI (Darmstadt) type laser, interactions
with matter can be studied in the upper 1020
W/cm2 regime. With such a laser focused into
an underdense plasma, strong electron bursts with energies
up to several 100 MeV are ejected in a forward direction.
This leads to a comparable burst of bremsstrahlung radiation
in the presence of high-Z material. Here, we discuss
the corresponding γ-induced nuclear reactions including
secondary particle production, including pions. Due to
the threshold behavior in the production, and the advantage
of delayed detection, we propose to employ these reactions
for probing the initial plasma conditions.
A Method for Modular Robots Generating Dynamics Automatically
Authors: Fei Yanqiong , Zhao Zigang , Song Libo
Published: July 2002

In this paper a method for the automatic generation
of dynamics for modular robots is presented. A modular reconfigurable
robot consists of link modules and joint modules of various
specifications. We analyze the abstract architecture of modular robots. A
total of nine types of connecting forms and three types
of joint forms are identified with reference to their own
systems. The geometric relationships are derived by the group theory.
According to the modular idea, the formulations of the velocity,
acceleration and other essential equations of the link module and
the joint module are formed compensatively and recursively. Then the
dynamic model is generated automatically by a compensative and recursive
method.
Adaptive steering controller using a Kalman estimator for wheel-type agricultural tractors
Authors: Wu D. , Zhang Q. , Reid J. F.
Published: July 2002

This paper presents an adaptive steering controller for achieving accurate and prompt steering control with noisy steering command signals and drifting valve characteristics on an automated agricultural tractor with an electrohydraulic steering system. It is difficult to accomplish performance objectives with conventional PID controllers because of the effects of disturbances and unknown factors. The adaptive controller, consisted of an adaptive gain tuner and an adaptive nonlinearity compensator, was to overcome these performance obstacles. Test results indicated that this controller provided an effective means for achieving satisfactory steering control for automated tractor traveling on changing and unpredictable farm field courses.
A new approach to dynamic posture control
Authors: Vanel O. , Gorce P.
Published: July 2002

In this paper, we propose an approach which ensures the dynamic
stability of a biped robot called “BIPMAN”. It is based on the correction of the
trunk center of mass acceleration and on the distribution of the forces exerted
by the limbs on the trunk. This latter is performed by means of a linear
programming method (the simplex method). The retained criterion allows to
optimize force distribution as well as trunk roll and pitch angles. Weighting
factors are introduced into this criterion in order to define criteria adapted
to specific tasks. Modifying these factors is a solution to the task transition
problem. Many simulation results are presented to demonstrate criteria and
constraints influences on dynamic stability. They lead us to introduce a new
approach called RTCA (Real Time Criteria and
Constraints Adaptation). This relies on the analysis of
position, velocity and acceleration vectors for criterion real time adaptation
and on forces analysis for constraints real time adaptation. The RTCA approach is finally validated through simulations results for a specific
task.
Multi-legged walking machine body design
Authors: Zhang S.J. , Howard D. , Sanger D.J. , Miao S.
Published: July 2002

The effects of body geometry on walking machine performance have been
investigated, and a body design procedure proposed. The relationships between
static workspace, body-geometry and installed joint torques have been derived.
A body design procedure that uses this data is then described, and two design
examples discussed. The procedure results in a body geometry which minimises
the installed joint torques, and hence the machine weight, for the desired
workspace area.
The synthesis of 3-D form-closure grasps
Authors: Ding Dan , Liu Yun-Hui , Wang Shuguo
Published: July 2002

This paper presents a new formulation of computing three-dimensional (3-D) frictional form-closure grasps of n robotic fingers. As 3-D form-closure grasps involve 6-D wrench space, we first propose a recursive reduction technique to transform the complicated problem in the 6-D space into a simpler 3-D one. Next, we rewrite the sufficient and necessary condition for form-closure grasps into its equivalent form of two sets of linear inequalities. Then, according to the linear inequality theory, the problem is transformed to searching for a set of points which ensure the inconsistency of each of the two linear inequality systems. To search for such points, we proposed two methods: The first
one is based on testing whether the convex region formed by each linear inequality system is empty, while the second one relies on the potential field method. We have implemented the algorithm and confirmed their efficiency for the synthesis of 3-D form-closure grasps.
Sensor information space for robust mobile robot path planning
Authors: Pruski A. , Atassi A.
Published: July 2002

This paper introduces a new approach to robust path planning for mobile robots entirely based on information from environment perception sensors. This method avoids the use of odometry which leads to the accumulation of errors resulting from the robot's

position computing. We proceed as follows: we create regions inside which the robot detects the same obstacle segments. A node graph represents all the regions and their links. Then a

planning algorithm is used to find a path which joins a start to a goal region. The final stage consists in applying a robust robot motion control as regards the uncertainties of the environment model. This approach contributes to a control system for indoor robots which is environment referenced. The sensors we deal with are first a continuous laser or ultrasonic scanning system, then a discrete ultrasonic belt whose limits of use we show.
Vision-based playback method of wheeled mobile robots
Authors: Kagami Yoshiyuki , Emura Takashi , Hiyama Masayuki
Published: July 2002

This paper describes a new vision-based playback method of a wheeled mobile robot.
The path of the robot is divided into straight line parts and curved line parts. The curved line parts were approximated by a Bézier curve to decrease the volume of data. In order to track the curved line parts with good accuracy, tracking errors were detected by referring to two pre-recorded images on one part of the curve. Then, the errors were corrected by adjusting the control points of the Bézier curve. Outdoor experiments demonstrated good repeatability by using the proposed method.
The rights and wrongs of school music: considering the expressivist argument and its existential component
Authors: Finney John
Published: July 2002

All reflective music educators ponder the questions posed by this title. Over the years, they have channelled an enormous amount of energy into the improvement of musical teaching and learning in our schools. Ross (1995) argues that these efforts continue to be futile, for the basis of thought and practice is misconceived. This paper examines Ross's thesis highlighting and developing its existential component. A case study illustrates the argument for placing authentic self-expression and ‘music proper’ within the context of wider contemporary debate.
A CORRECTION FACTOR FOR UNIT ROOT TEST STATISTICS
Authors: Bravo Francesco
Published: July 2002

Despite the fact that it is not correct to speak
of Bartlett corrections in the case of nonstationary time
series, this paper shows that a Bartlett-type correction
to the likelihood ratio test for a unit root can be an
effective tool to control size distortions. Using well-known
formulae, we obtain second-order (numerical) approximations
to the moments and cumulants of the likelihood ratio, which
makes it possible to calculate a Bartlett-type factor.
It turns out that the cumulants of the corrected statistic
are closer to their asymptotic value than the original
one. A simulation study is then carried out to assess the
quality of these approximations for the first four moments;
the size and the power of the original and the corrected
statistic are also simulated. Our results suggest that
the proposed correction reduces the size distortion without
affecting the power too much.
Reproductive phenology of gingers in a lowland mixed dipterocarp forest in Borneo
Authors: Sakai Shoko
Published: July 2002

Reproductive phenology of 117 individuals from a total of 20 ginger species (Costaceae and Zingiberaceae) was monitored for up to 21 mo in a lowland mixed dipterocarp forest in the Lambir Hills National Park, Sarawak. Of these 20 species of iteroparous perennials, pollinated by either spiderhunters (Nectariniidae), medium-sized Amegilla bees (Anthophoridae), or small halictid bees (Halictidae), many reproduced more than once a year, or flowered continuously with short interruptions. Significant but weak synchronization in flowering events among conspecific individuals was detected for only two species out of the five examined (Etlingera aff. metriocheilos and Amomum somniculosum). The low synchronization within the population, the overlapping flowering among species sharing common pollinators, and the high flowering frequency for each species, contrast markedly with the reproductive phenology of hummingbird-pollinated and large bee-pollinated plants of related taxa in the Neotropics. Although the plants studied do not include all members of each pollination guild, at least one species within a guild was flowering at any time except in the spiderhunter-pollinated guild. Some bee-pollinated gingers may serve as keystone species for survival of the traplining bees living on floral nectar and pollen.
The effects of forest type, harvesting and stand refinement on early seedling recruitment in a tropical rain forest
Authors: FORGET PIERRE-MICHEL , RANKIN-DE MERONA JUDY M. , JUILLOT CATHERINE
Published: July 2002

Maintenance of high plant diversity in tropical rain forests has been hypothesized to be related to intense
seed predation, and studies have shown that the impact of seed-eaters varies according to seed size, forest type and
level of disturbance. The hypothesis that seed survival and seedling recruitment depending on seed size, are related to
forest type and the intensity of harvesting and stand refinement was therefore tested at Paracou, French Guiana, for
three animal-dispersed tree species. Two forest areas, corresponding to two forest types, were selected based on the
occurrence of a dominant species, Eperua falcata (Caesalpiniaceae). Two factors were tested: forest type (E. falcata-rich
and E. falcata-poor) and level of harvesting (unlogged, low intensity of logging, low intensity of logging and thinning
liberation by tree-poison girdling) within each forest type. Overall, there was no effect of species nor of logging
treatment within forest type after 6 wk. There was only a significant effect of forest type on seed survival in the
large-seeded Carapa procera, a rodent-dispersed species in the Meliaceae. In the two medium-sized seed species,
Pradosia cochlearia and Manilkara bidentata, two frugivore-dispersed Sapotaceae, the effect of treatment was overall
significant but was also highly variable between plots within treatments. After 1 y, C. procera showed little seedling
recruitment due to low seed removal and dispersal, and high seed-seedling predation under all conditions. Neither
forest type, nor treatment nested within forest type, affected seedling recruitment in P. cochlearia whereas M. bidentata
seedlings were favoured in unlogged conditions at the E. falcata-poor forest type. These results suggest that species
characteristics (such as seed size and palatability), or local tree diversity and resources for granivores select for
contrasting patterns in tree recruitment between forest type in the rodent-dispersed tree species, and these interact with
level of tree harvesting and stand refinement in the other frugivore-dispersed tree species.
Effects of light availability and rainfall on leaf production in a moist tropical forest in central Panama
Authors: BARONE JOHN A.
Published: July 2002

New leaf production in seasonal tropical forests may result from changes in water or light availability. In this study, the relationship between leaf flushing, photosynthetically active radiation (PAR) and rainfall was examined for understorey saplings in a moist tropical forest over one year. During the wet season, weeks with greater PAR were correlated with a greater proportion of saplings flushing new leaves during subsequent weeks in nine out of ten species. Rainfall was negatively correlated with subsequent leafing during the wet season for six of ten species. However, during the dry season, rainfall was positively correlated with leafing during the following weeks for six species, but the relationship was much weaker. PAR in the dry season was negatively correlated with flushing in eight species. These results support the hypothesis that under well-watered conditions, light limits leaf production, and peaks in insolation result in greater leaf production.
Growth and survival of aerial roots of hemiepiphytes in a lower montane tropical moist forest in Panama
Authors: Patiño Sandra , Gilbert Gregory S. , Zotz Gerhard , Tyree Melvin T.
Published: July 2002

Hemiepiphytic plants grow for part of their life as true epiphytes, then become terrestrial through the production of aerial roots that grow from the canopy to the ground. Long-term measurement of growth, dieback and mortality of aerial roots of hemiepiphytic plants in a lower montane moist tropical forest in western Panama was used to elucidate life-history strategies of hemiepiphytes from two families. The fates of 156 aerial roots of five species of Clusiaceae and Araceae were followed for 10 mo. Some roots were cut to experimentally study the effect of injury on resprouting and survival. Aerial roots of Araceae grew more than twice as fast as those of Clusiaceae but had a much greater mortality rate. Roots of both families grew much faster during the wet than dry season. Even for the fastest growing roots, growth and survival models suggest that only 18% of Araceae roots were likely to survive long enough to reach the ground from a branch 10 m high, whereas 87% of roots of Clusiaceae were likely to do so. This suggests that only those Araceae hemiepiphytes that produce a large number of aerial roots or are located close to the ground are likely to reach the soil.
Migration, family structure and pauper lunacy in Victorian England:

admissions to the Devon County Pauper Lunatic Asylum, 1845–1900
Authors: ADAIR RICHARD , MELLING JOSEPH , FORSYTHE BILL
Published: July 2002

The lunatic asylum remains one of the most remarkable institutional

monuments of the modern world, dominating the social landscape of
Victorian Britain and exercising a powerful attraction for social historians

of medicine, an attraction almost as great as the spectre of the madhouse

for contemporary novelists. Our image of the Victorian asylum is still

pervaded to a surprising degree by the gloomy spectacle of the total
institution presented by Michel Foucault, though it has been modified by

a whole range of institutional and philosophical accounts undertaken in

the past three decades. Pioneering studies by researchers such as Andrew

Scull have illuminated not only the power exercised by the new asylum
superintendents, armed with medical discourses of moral treatment and
the early promise of curability, but also the continuing dominance of the

‘mad doctors’ in the sombre years of neo-Darwinian pessimism
and
eugenics doctrines. More recent contributions to the now enormous
literature on the social history of insanity have shifted the focus of

attention from earlier concerns with charting the rise of the asylum and

the elaboration of medical discourses under the psychiatric gaze of
physicians to a detailed reconstruction of the social environment of the

asylum and especially to the interplay between familial circumstances and

the way institutions responded to the insane. Such concerns were also
clearly evident in important earlier studies by Walton, Scull, Digby and

others, which drew on fundamental work by Anderson on the changing
role of the family during industrialization. These scholars drew attention

to the importance of family and kinship relations in the negotiation of
a
lunatic's passage to the Victorian asylum, as well as the role of
wider
forces of economic change, population growth and migration in shaping
the environment in which decisions about the care of the mad were made.
Roots of SPAR — Shared Planning and Activity Representation
Authors: TATE AUSTIN
Published: July 2002

The Defense Advanced Research Projects Agency (DARPA) and US Air Force Research Laboratory Planning Initiative (ARPI) has initiated a project to draw on the range of previous work in planning and activity ontologies to create a practically useful Shared Planning and Activity Representation (SPAR) for use in technology and applications projects within their communities. This article describes the previous work which has been used to create the initial SPAR representation. Key examples of the work drawn upon are published in this issue. The paper provides a comprehensive bibliography and related world wide web resources for work in the area of plan, process and activity representation. SPAR is now being subjected to refinement during several review cycles by a number of expert and user panels.
VECTOR-VALUED MARKOV DECISION PROCESSES WITH AVERAGE REWARD
CRITERION: THE MULTICHAIN CASE
Authors: Wakuta Kazuyoshi
Published: July 2002

We study the multichain case of a vector-valued
Markov decision process with average reward criterion.
We characterize optimal deterministic stationary policies
via systems of linear inequalities and discuss a policy
iteration algorithm for finding all optimal deterministic
stationary policies.
QUASI-PRODUCT FORM TO A MULTINODE QUEUEING SYSTEM WITH A
COMMON EXPONENTIAL SETUP SERVER
Authors: Yamazaki Genji
Published: July 2002

We consider a K-node queueing system sharing
a setup server. Each node has a node server, a waiting
position, and a service position, and it behaves as an
M/G/1/2 type queue except that each job in the waiting
position requires a setup by the setup server to move to
the service position. The service discipline of the setup
server is nonpreemptive work-conserving random selection.
The setup times have a common exponential distribution.
The main purpose of this paper is to derive the stationary
distribution for the K-node system. For each node,
we construct a corresponding setup server queue (CSQ).
The stationary distribution of the K-node system
is given by a product form of the stationary distributions
of CSQs. This result enables us to obtain the stationary
distribution of a K-node system by analyzing individual
CSQs.
GEOMETRIC-FORM BOUNDS FOR THE GIX/M/1
QUEUEING SYSTEM
Authors: Economou Antonis
Published: July 2002

The GI/M/1 queueing system was long ago studied
by considering the embedded discrete-time Markov chain
at arrival epochs and was proved to have remarkably simple
product-form stationary distributions both at arrival epochs
and in continuous time. Although this method works well
also in several variants of this system, it breaks down
when customers arrive in batches. The resulting
GIX/M/1 system has no tractable stationary
distribution. In this paper we use a recent result of Miyazawa
and Taylor (1997) to obtain a stochastic upper bound for
the GIX/M/1 system. We also introduce a
class of continuous-time Markov chains which are related to
the original GIX/M/1 embedded Markov chain
that are shown to have modified geometric stationary distributions.
We use them to obtain easily computed stochastic lower bounds
for the GIX/M/1 system. Numerical studies
demonstrate the quality of these bounds.
NEGOTIATED INTERACTION IN TARGET LANGUAGE CLASSROOM
DISCOURSE.Jamila Boulima. Amsterdam: Benjamins, 1999. Pp. xiv + 338.
$79.00 cloth.
Authors: Mackey Alison
Published: July 2002

The topic of this book, part of a new series published by Benjamins entitled Pragmatics
and beyond, is negotiated interaction. It begins with a lengthy introduction to the subject
matter, and then presents an empirical study of negotiated interaction in English as a foreign
language classrooms in Morocco. The first two chapters (a third of the text) seek to
operationalize interaction and define the role of negotiated interaction in second language
acquisition (SLA). These chapters are useful in the sense that they provide a fairly comprehensive
review of the literature prior to 1991. However, the field has come a long way since that time, and
a decade of crucial work is missing from this 1999 book.
UNDERSTANDING SECOND LANGUAGE LEARNING DIFFICULTIES.Madeline E. Ehrman. Thousand Oaks, CA: Sage, 1996. Pp. xvii + 346. $25.95
paper.
Authors: Chamot Anna Uhl
Published: July 2002

The purpose of this book is to provide language teachers with insights and tools for
understanding some of the reasons why their adult students often encounter less-than-smooth
sailing when trying to learn another language. The book explores a variety of case studies that
involve real students, thus bringing to life the human dimension of the learning difficulties
presented. Although some examples of ESL students are provided, the major focus is on foreign
language learners. Ehrman's felicitous writing style ensures that the book reads like an
extended and intellectually stimulating conversation with the author.
THE ORIGINS OF GRAMMAR: EVIDENCE FROM EARLY LANGUAGE
COMPREHENSION.Kathy Hirsh-Pasek & Roberta Michnick Golinkoff.
Cambridge, MA: MIT Press, 1996. Pp. x + 230. $30.00 cloth.
Authors: Gelman Susan A.
Published: July 2002

The goals of this volume are: (a) to demonstrate that young children are sensitive to
properties of language structure (such as word order), (b) to detail a new method for studying
early language comprehension, (c) to provide a novel theoretical framework for understanding
early syntactic development, and (d) to provide a clear and accessible account of language
acquisition. The authors succeed splendidly on all four counts.
Reasoning about apparent contradictions: resolution
strategies and positive–negative asymmetries
Authors: SHARPE DEAN , LACROIX GUY
Published: July 2002

APPARENT CONTRADICTIONS, e.g. Did Susan like her supper? – Yes and no,
involve asserting and denying the same proposition. They therefore
violate the classical LAW OF NON-CONTRADICTION, suggesting the use of
non-classical INTERPRETIVE STRUCTURES in natural language and reasoning.
Experiment 1 explores the range of such interpretive structures
available to adults (n = 24) in their reasoning about an apparent
contradiction. Experiment 2 uses a similar task to study the emergence
of these interpretive structures in young children's reasoning (3;6 to
8;4, n = 48). Results suggest an early facility with resolution strategies
relating to OBJECT STRUCTURE (as in, Maybe Susan liked one part of supper
but didn't like another part) and an initial tendency to focus on the
negative by referring to it first (as in, Maybe Susan didn't like one part
of supper but did like another part). We discuss the results in terms of the
NATURAL LOGIC of objects and their properties, and the LOGICAL
RESOURCES available to young children.
On p-adic height pairings and locally free classgroups of
Hopf orders
Authors: AGBOOLA A.
Published: July 2002

Let E be an elliptic curve with complex multiplication
by the
ring of integers [Ofr ]
of an imaginary quadratic field K. The purpose of this paper is
to describe certain
connections between the arithmetic of E on the one hand and the
Galois module
structure of certain arithmetic principal homogeneous spaces arising from
E on the
other. The present paper should be regarded as a complement to [AT];

we assume that the reader is equipped with a copy of the latter paper and
that he is not averse
to referring to it from time to time.
Traceless tensors and invariants
Authors: MALIAKAS MIHALIS
Published: July 2002

For G a classical group of type Bn,

Cn or Dn
defined over an algebraically closed
field (of characteristic other than two if G is a special orthogonal
group), we show
that the centralizer algebra of G on the space of endomorphisms
of the module of
traceless tensors Wr is naturally isomorphic

to the group algebra of the symmetric
group Sr if r[les ]n
(for G of type Bn or Cn)

or if r<n (for G of type Dn).

This extends a characteristic zero result of Brauer and Weyl and recovers
some of the related
characteristic free results that De Concini and Strickland obtained for

G of type Cn.
On the finite generation of high dimensional cohomology ring of
virtually torsion-free groups
Authors: LEE CHUN-NIP
Published: July 2002

Let Γ be a discrete group and p be a prime.
One of the fundamental results in group
cohomology is that H*(Γ, [ ]p)

is a finitely generated [ ]p-algebra if Γ
is a finite group
[8, 24]. The purpose of this paper is
to study the analogous question when Γ is no longer finite.

Recall that Γ is said to have finite virtual cohomological dimension

(vcd) if there
exists a finite index torion-free subgroup Γ′ of Γ
such that Γ′ has finite cohomological
dimension over ℤ [4]. By definition vcd
Γ
is the cohomological dimension of Γ′. It is
easy to see that the mod p cohomology ring of a finite
vcd-group does not have to be
a finitely generated [ ]p-algebra in general.
For instance, if Γ is a countably infinite free product of ℤ's,
then
H1(Γ, [ ]p) is not
finite dimensional over [ ]p. The three most
important classes of examples of finite vcd-groups in which the

mod p cohomology ring is a finitely generated [ ]p-algebra

are arithmetic groups [2], mapping class groups
[9, 10] and outer automorphism groups of
free groups [5]. In each of these examples,
the proof of finite generation involves the construction of a specific
Γ-complex with
appropriate finiteness conditions. These constructions should be regarded
as utilizing
the geometry underlying these special classes of groups. In contrast, the
result we
prove will depend only on the algebraic structure of the group Γ.
Middle Latitude Sailing Revisited
Authors: Williams Roy
Published: July 2002

Many problems in navigation can be best viewed and solved as
problems in analytical geometry. We only need to understand the geometry
of two
‘navigable’ surfaces; the sphere and the ellipsoid of
revolution. The ellipsoidal model
is generated by revolving an ellipse about its minor axis and this model
is used as a global
model for the surface of the Earth. The eccentricity of the meridian ellipse
is small
(≈0·082) so we sometimes refer to this surface as a
‘spheroid’ since the surface is still
‘sphere-like’. The physical Earth is, in fact, referred to
as a
‘geoid’ whose surface is
that which approximates global mean sea level. The mathematical representation
of the
geoid is not trivial and the ellipsoid of revolution is an extremely good
approximation
to it.
Dynamic Environment Charting – the
next stage for Marine Electronic
Navigation
Authors: Fennessy Michael J.
Published: July 2002

Digital electronics have caused massive changes to navigation technology in the latter half
of the twentieth century. This paper presents an alternative view to much of the commentary
on the future of electronic navigation. It is written from a small craft perspective, although
the principles are of value to commercial and naval shipping. Essentially, it proposes the
development of environmental simulation as the basis for computer-hosted charting systems
on vessels. This is drawn from the author's experience of developing the DyGeo system for
environmental simulation, of which the navigation version forms a part. It stresses that much
of the additional data we have placed on charts this century has been cultural in content, and
necessitates a large bureaucratic system for its maintenance. An environmental system
requires different types of inputs, but can be largely self-maintaining. The advent of the
inexpensive, portable, personal computer has put this sort of facility in the hands of the
leisure mariner as well as professional navigators.