bluuebunny/crossref_metadata_2025 huggingface dataset:
Second-Order Statistics of Colour Codes Modulate Transformations That Effectuate Varying Degrees of Scene Invariance and Illumination Invariance
Authors: Mausfeld Rainer , Andres Johannes
Published: August 2002

We argue, from an ethology-inspired perspective, that the internal concepts ‘surface colours' and ‘illumination colours' are part of the data format of two different representational primitives. Thus, the internal concept of ‘colour’ is not a unitary one but rather refers to two different types of ‘data structure’, each with its own proprietary types of parameters and relations. The relation of these representational structures is modulated by a class of parameterised transformations whose effects are mirrored in the idealised computational achievements of illumination invariance of colour codes, on the one hand, and scene invariance, on the other hand. Because the same characteristics of a light array reaching the eye can be physically produced in many different ways, the visual system, then, has to make an ‘inference’ whether a chromatic deviation of the space-averaged colour codes from the neutral point is due to a ‘non-normal’, ie chromatic, illumination or due to an imbalanced spectral reflectance composition. We provide evidence that the visual system uses second-order statistics of chromatic codes of a single view of a scene in order to modulate corresponding transformations. In our experiments we used centre – surround configurations with inhomogeneous surrounds given by a random structure of overlapping circles, referred to as Seurat configurations. Each family of surrounds has a fixed space-average of colour codes, but differs with respect to the covariance matrix of colour codes of pixels that defines the chromatic variance along some chromatic axis and the covariance between luminance and chromatic channels. We found that dominant wavelengths of red — green equilibrium settings of the infield exhibited a stable and strong dependence on the chromatic variance of the surround. High variances resulted in a tendency towards ‘scene invariance’, low variances in a tendency towards ‘illumination invariance’ of the infield.
Perceptual Behavior: Recurrence Analysis of a Haptic Exploratory Procedure
Authors: Riley Michael A , Wagman Jeffrey B , Santana Marie-Vee , Carello Claudia , Turvey M T
Published: August 2002

Various object properties are perceptible by wielding. We asked whether the dynamics of wielding differed as a function of the to-be-perceived property. Wielding motions were analyzed to determine if they differed under the intention to perceive or not perceive rod length (experiment 1), to perceive object height versus object width (experiment 2), and to perceive the length forward of where the rod was grasped versus the position of the grasp (experiment 3). Perceiving these different properties is known to depend on different components of the object's inertia tensor. Analyses of the subtle recurrent patterns in the phase space of the hand motions revealed differences in wielding across the different perceptual intentions. Haptic exploratory procedures may exhibit distinct exploratory dynamics.
The Limited Capacity of Humans to Identify the Components of Taste Mixtures and Taste – Odour Mixtures
Authors: Laing David G , Link Catherine , Jinks Anthony L , Hutchinson Ian
Published: August 2002

The capacity of humans to identify the components of taste mixtures and odour – taste mixtures was investigated in two experiments. Subjects were trained to identify the components presented alone and to use a ‘yes/no’ procedure to identify them in mixtures. All stimuli were presented with a retronasal (by mouth) technique. A maximum of three tastants were identified in both types of mixtures, only one tastant was identified in five-component taste mixtures, and no component was identified in four-component odour – taste mixtures. Importantly, in no instance was the olfactory stimulus identified in any mixture with tastes, including binary mixtures. Loss of identity of the odorant in binary and ternary mixtures may have been due to suppression as a consequence of temporal processing, or to the absence of an association between the odorant and tastants that had established an identifiable percept. In contrast, poor identification of the components of the quaternary odour – taste mixture and quinternary taste mixture is attributed to the limited capacity of working memory. Overall, the poorer ability to identify components in odour–taste mixtures than in taste mixtures indicates that interactions occurred between the two senses, challenging the proposal that odours and tastes are processed independently when present in complex chemosensory stimuli.
Conditions under Which Stereopsis and Motion Perception are Blind
Authors: Kim Yong-Guk , Mollon John D
Published: August 2002

We describe modified random-dot stereograms in which the corresponding elements differ from non-corresponding elements in colour, size, and luminance. Despite these visible differences between the elements, depth perception collapses when the spatially integrated luminous flux is similar for the corresponding and non-corresponding elements. Our results suggest that a low-pass spatial filter precedes the mechanism that recognises disparity. A similar phenomenon is observed for the perception of coherent motion in random-dot kinematograms. Our modified stereograms and kinematograms may find other uses when experimenters wish to study the contribution of colour to visual processes and require a method of eliminating edge artifacts.
Absolute and Relative Effects of Similarity and Distance on Grouping
Authors: Masin Sergio Cesare
Published: August 2002

Four experiments are reported, the aim of which was to explore the achromatic-colour and distance relations that determine the probability of achromatic surfaces grouping perceptually. The first two experiments were performed to test Wertheimer's conjecture that similarity and dissimilarity of achromatic colours jointly determine grouping. The results indicate that only similarity of achromatic colours determines grouping. Data from the other two experiments show that grouping is determined by absolute, relative, and Gillam's distances. These findings agree with previous literature showing that different algorithms or mechanisms determine grouping by similarity and grouping by distance. Additionally, these findings show that the single factor of grouping by distance also depends on multiple algorithms or mechanisms.
Consistent Stereoscopic Information Increases the Perceived Speed of Vection in Depth
Authors: Palmisano Stephen
Published: August 2002

Previous research found that adding stereoscopic information to radially expanding optic flow decreased vection onsets and increased vection durations (Palmisano, 1996 Perception & Psychophysics58 1168–1176). In the current experiments, stereoscopic cues were also found to increase perceptions of vection speed and self-displacement during vection in depth—but only when these cues were consistent with monocularly available information about self-motion. Stereoscopic information did not appear to be improving vection by increasing the perceived maximum extent of displays or by making displays appear more three-dimensional. Rather, it appeared that consistent patterns of stereoscopic optic flow provided extra, purely binocular information about vection speed, which resulted in faster/more compelling illusions of self-motion in depth.
The Nature of the 'Mono' Ligand Complexes of Iron(II) with 1,10-Phenanthroline-2-carbothioamide and 2,2´-Bipyridine-6-carbothioamide. Low-Spin Iron(II) and High-Spin Iron(III) Systems
Authors: Childs Bradley C. , Goodwin Harold A.
Published: August 2002

Interaction of 2,2′-bipyridine-6-carbothioamide (bta) with iron(II) chloride leads to three different products: [Fe(bta)2]Cl2·H2O, [Fe(bta)2][FeCl4] and an apparently ‘mono’-ligand complex analogous to the previously described Fe(pta)Cl2·H2O (pta = 1,10-phenanthroline-2-carbothioamide). Electronic and Mössbauer spectroscopic data show that all three complexes of bta contain the [Fe(bta)2]2+ cation. The Mössbauer spectra, together with the magnetic properties, indicate that the [Cl3Fe–O–FeCl3]2– ion is associated with the cation in the ‘mono’ complex which is formulated as [Fe(bta)2]2[Cl3Fe–O–FeCl3]Cl2·3H2O. The unusual temperature dependence of the Mössbauer spectrum, and the magnetism of this complex, arises from the presence of different iron sites, one being low-spin iron(II) and the other high-spin iron(III). Two of the latter are antiferromagnetically coupled in the oxobridged anion. 2,2′-Bipyridine-6-carboxamide (bca) yields an iron(II) mono-ligand derivative, Fe(bca)Cl2·H2O, which is a simple high-spin paramagnet.
Contrasting effects of chronic heat stress and heat shock on kernel weight and flour quality in wheat
Authors: Wardlaw Ian F. , Blumenthal Caron , Larroque Oscar , Wrigley Colin W.
Published: August 2002

Phytotron studies were conducted to compare the potential effects of chronic
high-temperatures (daily maxima of over 20˚C) and heat-shock conditions
(a few days of over 32˚C), on wheat
(Triticum aestivum L.) yield and quality, to form a
basis for the selection of improved high-temperature tolerance in wheat. The
series of heat-shock treatments were designed to provide similar heat loads,
by varying the duration (number of days) of each treatment. Studies involved
two cultivars, Lyallpur and Trigo 1. Both showed a reduction in kernel weight
in response to chronic high day temperatures (i.e. above 18˚C), with
Trigo 1 more tolerant than Lyallpur. Kernel weight of both cultivars was also
reduced by short periods of heat shock, and this was most evident at
day/night temperatures above 30/25˚C. There was no reduction in
the germination of the lighter weight kernels formed under either chronic high
temperature or heat-shock conditions. Dough strength, as judged by mixing
time, declined in both genotypes with prolonged chronic high temperature, and
also following the most extreme of the heat-shock treatments — Trigo 1
showed an ability to resist these changes better than Lyallpur. The
heat-related decreases in dough strength were associated with decreases in the
proportion of the larger molecular size glutenin (most
‘unextractable’). This change in quality was not however,
associated with changes in flour protein content.
Consequences of intrauterine growth restriction on ventilatory and thermoregulatory responses to asphyxia and hypercapnia in the newborn guinea-pig
Authors: Tolcos Mary , Rees Sandra , McGregor Hugh , Walker David
Published: August 2002

The purpose of this study was to determine the effects of prenatal growth
restriction on the ventilatory and thermoregulatory responses to asphyxia and
hypercapnia in the newborn guinea-pig. Spontaneously growth-restricted (SGR)
animals born to unoperated dams, and growth-retarded (GR) neonates born to
dams in which a uterine artery had been ligated at mid gestation, were studied
and compared with control neonates. Ventilatory responses to progressive
asphyxia and steady-state hypercapnia were tested at 3–6 days of age
using a barometric plethysmograph. The animals were then killed and the brains
prepared for histological and immunohistochemical analysis. During progressive
asphyxia, SGR neonates (n = 5) had a
significantly increased minute ventilation compared with both control
(n = 6) and GR (n =
5) neonates. Rectal temperature fell significantly in GR and SGR neonates
after progressive asphyxia, but was unchanged in control neonates. The
ventilatory responses to steady-state hypercapnia were not different in the
GR, SGR and control neonates. The immunoreactive expression of glial
fibrillary acidic protein, tyrosine hydroxylase, substance P and
met-enkephalin in the medulla was also not different between the three groups.
It was concluded that prenatal growth restriction is associated with
alterations in the respiratory and thermoregulatory responses to asphyxia and
hypercapnia, with greater effects observed when in utero
growth restriction arises spontaneously, compared with that produced
experimentally over approximately the last half of gestation.
Distributions of species of the Antechinus stuartii-A. flavipes complex as predicted by bioclimatic modelling
Authors: Crowther M. S.
Published: August 2002

Previous work on bioclimatic mapping of species within the
Antechinus stuartii–A. flavipes complex has been
carried out, but this was before A. subtropicus was
recognised and a complete taxonomic revision of the complex had been
completed. This revised study of bioclimatic modelling of species within the
A. stuartii–A. flavipes complex indicates
substantial differences between the four species
(A. stuartii, A. agilis,
A. subtropicus and A. flavipes) in
35 climatic indices. A. stuartii is predicted to have a
near-coastal distribution in northern and central New South Wales stretching
as far south as Kioloa and as far north as south-eastern Queensland, avoiding
the far coastal strip. A. agilis is predicted to have an
extensive distribution in Victoria and southern New South Wales as far north
as western Sydney; it is also predicted to occur in Tasmania, even though
there is no evidence of it ever occurring there.
A. flavipes is predicted to have an extensive inland and
coastal distribution much larger than its recorded distribution.
A. subtropicus is predicted to have a very narrow
distribution in areas with high seasonal rainfall and high temperatures with
low seasonality. All species are predicted to occur sympatrically, with
A. stuartii and A. agilis
predicted to have extensive overlap on the coast near Kioloa and to the
immediate west and south-west of Sydney.
ON THE DEALER'S RANDOMNESS REQUIRED IN PERFECT SECRET SHARING SCHEMES WITH ACCESS STRUCTURES OF CONSTANT RANK
Authors: SUN HUNG-MIN
Published: August 2002

A secret sharing scheme is a method which allows a dealer to share a secret among a set of participants in such a way that only qualified subsets of participants can recover the secret. The collection of subsets of participants that can reconstruct the secret in this way is called access structure. The rank of an access structure is the maximum cardinality of a minimal qualified subset. A secret sharing scheme is perfect if unqualified subsets of participants obtain no information regarding the secret. The dealer's randomness is the number of random bits required by the dealer to setup a secret sharing scheme. The efficiency of the dealer's randomness is the ratio between the amount of the dealer's randomness and the length of the secret. Because random bits are a natural computational resource, it is important to reduce the amount of randomness used by the dealer to setup a secret sharing scheme. In this paper, we propose some decomposition constructions for perfect secret sharing schemes with access structures of constant rank. Compared with the best previous results, our constructions have some improved upper bounds on the dealer's randomness and on the efficiency of the dealer's randomness.
MODULAR THEORY AND GEOMETRY
Authors: SCHROER B. , WIESBROCK H.-W.
Published: August 2002

In this communication we present some new results on modular theory in the context of quantum field theory. In doing this we develop some new proposals how to generalize concepts of finite dimensional geometrical actions to infinite dimensional "hidden" symmetries. The latter are of a purely modular origin and remain hidden in any quantization approach.

The spirit of this work is more on a programmatic side, with many details remaining to be elaborated.
THE LORENTZ–DIRAC EQUATION, II
Authors: RUF BERNHARD , SRIKANTH P. N.
Published: August 2002

This paper continues the study of the Lorentz–Dirac equation [Formula: see text], which was begun in [6]. In particular, we study the qualitative behaviour of Dirac's so-called "non runaway" solutions modelling motions of particles which are reflected respectively transmitted by an obstacle given by the potential function V (x). We show that if the potential has a sufficiently sharp maximum, then the solutions oscillate a certain number of times around the maximum of the potential before being reflected or transmitted.
DECONSTRUCTING MONOPOLES AND INSTANTONS
Authors: LANDI GIOVANNI
Published: August 2002

We give a unifying description of the Dirac monopole on the 2-sphere S2, of a graded monopole on a (2, 2)-supersphere S2, 2 and of the BPST instanton on the 4-sphere S4, by constructing a suitable global projector p via equivariant maps. This projector determines the projective modules of finite type of sections of the corresponding vector bundle. The canonical connection ∇ = p ◦ d is used to compute the topological charge which is found to be equal to -1 for the three cases. The transposed projector q = pt gives the value +1 for the charges; this showing that transposition of projectors, although an isomorphism in K-theory, is not the identity map. We also study the invariance under the action of suitable Lie groups.
ANALYTICAL CRITERIA FOR LOCAL ACTIVITY OF REACTION–DIFFUSION CNN WITH FOUR STATE VARIABLES AND APPLICATIONS TO THE HODGKIN–HUXLEY EQUATION
Authors: MIN LEQUAN , CROUNSE KENNETH R. , CHUA LEON O.
Published: August 2002

This paper presents analytical criteria for local activity in reaction–diffusion Cellular Nonlinear Network (CNN) cells [Chua, 1997, 1999] with four local state variables. As a first application, we apply the criteria to a Hodgkin–Huxley CNN, which has cells defined by the equations of the cardiac Purkinje fiber model of morphogenesis that was first introduced in [Noble, 1962] to describe the long-lasting action and pace-maker potentials of the Purkinje fiber of the heart. The bifurcation diagrams of the Hodgkin–Huxley CNN's supply a possible explanation for why a heart with a normal heart-rate may stop beating suddenly: The cell parameter of a normal heart is located in a locally active unstable domain and just nearby an edge of chaos. The membrane potential along a fiber is simulated in a Hodgkin–Huxley CNN by a computer. As a second application, we present a smoothed Chua's circuit (SCC) CNN. The bifurcation diagrams of the SCC CNN's show that there does not exist a locally passive domain, and the edges of chaos corresponding to different fixed-cell parameters are significantly different. Our computer simulations show that oscillatory patterns, chaotic patterns, or divergent patterns may emerge if the selected cell parameters are located in locally active domains but nearby the edge of chaos. This research demonstrates once again the effectiveness of the local activity theory in choosing the parameters for the emergence of complex (static and dynamic) patterns in a homogeneous lattice formed by coupled locally active cells.
Holonomic and Legendrian parametrizations of knots
Authors: Birman Joan S. , Wrinkle Nancy C.
Published: August 2002

Holonomic parametrizations of knots were introduced in 1997 by Vassiliev, who proved that every knot type can be given a holonomic parametrization. Our main result is that any two holonomic knots which represent the same knot type are isotopic in the space of holonomic knots. A second result emerges through the techniques used to prove the main result: strong and unexpected connections between the topology of knots and the algebraic solution to the conjugacy problem in the braid groups, via the work of Garside. We also discuss related parametrizations of Legendrian knots, and uncover connections between the concepts of holonomic and Legendrian parametrizations of knots.
THE JONES POLYNOMIALS OF FREELY PERIODIC KNOTS
Authors: CHBILI Nafaa
Published: August 2002

For knots in S3 criteria for free periodicity are obtained in terms of the bracket and the Jones polynomials. The criteria introduced in this paper generalize the result obtained by Murasugi for the Jones polynomials of periodic knots.
LONG-RUN AVAILABILITY OF A ROBOT-SAFETY DEVICE SYSTEM
Authors: VANDERPERRE E. J. , MAKHANOV S. S.
Published: August 2002

We consider a robot-safety device system attended by two different repairmen. The system is characterized by the natural feature of cold standby and by an admissible "risky" state. In order to describe the random behavior of the entire system (robot, safety device, repair facility) we introduce a stochastic process endowed with probability kernels satisfying general Kolmogorov-type equations. Next, we derive the long-run availability of the robot-safety system. Some numerical examples are provided. Finally, as an application, we consider the particular but important case of fast repair.
X-RAY PHOTOELECTRON SPECTROSCOPY STUDIES OF THE STABILITY OFAl/Mg/PETINTERFACES
Authors: KONO M. , WONG P. C. , LI Y. S. , MITCHELL K. A. R.
Published: August 2002

The interfacial chemistry of an Al/Mg/PET sample, prepared by thermally evaporating first Mg and then Al on to a polyethyleneterephthalate (PET) film, was studied by X-ray photoelectron spectroscopy (XPS). The Mg/PET system showed two types of Mg species, namely an O–Mg–C complex, from reaction with the carbonyl group on PET, and metal-like clusters. The deposition of Al results in intermetallic mixing, which is manifested by alloy formation and Mg enrichment at the surface. It appears that some Al atoms penetrate the Mg region to react with carbonyl groups in the PET and form an interfacial complex with O–Al–C bonding. The stability of this sample was studied on exposing it to air and then rinsing it with water. The metal overlayers are strongly modified by these treatments, although the bonding at the PET interface appears relatively unchanged.
SUPPORTING DISTRIBUTED AUTONOMOUS INFORMATION SERVICES USING COORDINATION
Authors: GAL AVIGDOR , MYLOPOULOS JOHN
Published: August 2002

The large quantity and often questionable quality of available information in the information age provides a shaky foundation for decision making by individuals and organizations alike. This has created a tremendous demand for information services which can access, filter, process and present information on an as-needed basis. However, two factors complicate the design of such information services, namely the distributed and the autonomous nature of data sources.

This paper reports on the design and implementation of a generic architecture for supporting information services, which meets the above challenge. The architecture adopts concepts from conceptual modeling to offer a transparent description of the information sources' setting and uses active databases techniques to offer a declarative, event-based language for defining coordination rules for integrating distributed information services. Accordingly, the proposed architecture supports two of the most prominent utilities of information services, namely the pre-designed flow of operations and the reactive provision of information.

In addition to describing the architecture and illustrating its features with an example, the paper presents a prototype implementation and reports on some experimental performance results.
Nitric Oxide: A Review for Veterinary Surgeons
Authors: Howe Lisa M. , Boothe Harry W.
Published: August 2002

Nitric oxide (NO) is an endogenous gas that serves as a biologic messenger in many physiologic processes including neurotransmission, blood‐pressure control, the immune system's ability to kill tumor cells, and wound healing. NO is produced after oxidation of L‐arginine by a family of nitric oxide synthase (NOS) enzymes. Two of the NOS enzymes are present continuously and are thereby termed constitutive NOS. One of the enzymes, inducible NOS, is not typically expressed in resting cells and is induced by various substances including endotoxin, some cytokines, and microbial products. Thus, NO often has paradoxical activities. When NO is over‐ or underproduced, it can result in potentiation of disease states with disastrous results. This review discusses the biochemistry of NO, its functions in normal and disease states, and therapy for modulating NO production in disease states.
Pharmacokinetics and pharmacodynamics of methadone enantiomers after a single oral dose of racemate
Authors: Boulton David W. , Arnaud Philippe , DeVane C. Lindsay
Published: August 2002

Background

The pharmacokinetics and dynamics of methadone are characterized by high interindividual variability. This study aimed to examine a number of factors that may contribute to this variability.

Methods

Eight healthy drug‐free women were administered 0.2 mg/kg of R,S‐methadone orally. The concentrations of methadone's enantiomers in plasma and urine were monitored for 96 hours. Vital signs, blood biochemical parameters, and pupillary diameter were monitored frequently during this period. Cytochrome P450 3A (CYP3A) activity and α1‐acid glycoprotein (α1‐AGP) concentrations and phenotypes were determined. Pharmacokinetic and pharmacodynamic modeling was used to assess the influence of the above‐mentioned covariables on methadone enantiomer disposition and actions.

Results

The pharmacokinetic profile of the active enantiomer of methadone, R‐methadone, showed a relatively normal distribution with 38% to 90% of the interindividual variability in modeled pharmacokinetic parameters being explained by their individual variability in CYP3A activity, the cumulative amount of the main CYP3A4 metabolite, 2‐ethylidene‐1,5‐dimethyl‐3,3‐diphenylpyrolidine, excreted in the urine, the fraction unbound in plasma, and the α1‐AGP orosomucoid 2 (ORM2) variant plasma concentration. S‐Methadone showed an idiosyncratic distribution with largely unpredictable pharmacokinetics. Pupillary constriction response was highly variable between individuals.

Conclusions

The disposition of the active enantiomer, R‐methadone, can be predicted in part by CYP3A activity and protein binding to α1‐AGP (ORM2), whereas S‐methadone disposition is not well explained by the factors examined in this study. Central nervous system effects were difficult to interpret on the basis of plasma R‐methadone pharmacokinetics.

Clinical Pharmacology & Therapeutics (2001) 70, 48–57; doi: 10.1067/mcp.2001.116793
Effect of growth hormone on hepatic cytochrome P450 activity in healthy elderly men
Authors: Jürgens Gesche , Lange Kai Henrik Wiborg , Reuther Lene Ørskov , Rasmussen Birgitte Buur , Brøsen Kim , Christensen Hanne Rolighed
Published: August 2002

Objective

Our objective was to study the effect of recombinant human growth hormone (rhGH) on hepatic cytochrome P450 (CYP) activity in 30 healthy elderly men.

Methods

The study was carried out as a randomized, double‐blind, placebo‐controlled parallel‐group study. rhGH or placebo was administered for a period of 12 weeks. CYP activity was measured before, after 12 weeks of rhGH and placebo administration, and at 4 weeks after termination of rhGH and placebo administration with use of the biomarker reactions of CYP1A2 (caffeine), CYP2C19 (mephenytoin), CYP2D6 (sparteine), CYP3A4 (endogenous cortisol metabolism), and antipyrine clearance as common markers of CYP activity.

Results

The metabolic ratio of caffeine increased significantly in the group that received growth hormone compared with placebo (median difference, 4.55; 95% confidence interval (CI), 1.64 to 8.60; versus −0.90; 95% CI, −5.70 to 1.36), indicating an induction of CYP1A2. Moreover, the S/R ratio of mephenytoin showed a small but significant increase (median difference, 0.02; 95% CI, 0 to 0.31; versus 0; 95% CI, −0.01 to 0.06), indicating an inhibition of CYP2C19. There were no significant changes of the metabolic ratios of cortisol and sparteine or the antipyrine clearance compared with placebo.

Conclusions

These results indicate that growth hormone induces CYP1A2 and, to a lesser extent, inhibits CYP2C19 in elderly men, but it exerts no effects on CYP2D6 and CYP3A4. Although the induction of CYP1A2 may be of some clinical relevance, the small inhibition of CYP2C19 is probably unimportant.

Clinical Pharmacology & Therapeutics (2002) 71, 162–168; doi: 10.1067/mcp.2002.121373
Thoughts from the Editor
Authors: Reidenberg Marcus M.
Published: August 2002

Clinical Pharmacology & Therapeutics (2002) 71, 1–2; doi: 10.1067/mcp.2002.121968
Regions, Localities, and Industrialisation: Evidence from the East Midlands Circa 1780 – 1840
Authors: Stobart Jon
Published: August 2002

Regions form one of the fundamental categories of geographical thought and analysis and yet are far from being fixed spatial entities. Analysis of the East Midlands in the 19th century highlights three important aspects of regional development. The first aspect is that causality was not unilinear. Industrialisation reinforced strong local specialisms and allegiances rather than generating the wider integrated regional economies and identities seen in other industrialising areas. The second aspect is the importance of scale. There was no preordained size for a region: coherent economic and cultural units in the East Midlands operated at a more localised level. The third aspect is the significance of temporal continuity, seen in the persistent centring of economy, social cohesion, and identity onto established urban centres, despite the coalescing forces unleashed by industrial and technological change.
Dwelling, Place, and Landscape: An Orchard in Somerset
Authors: Cloke Paul , Jones Owain
Published: August 2002

In this paper we seek to develop the concept of dwelling as a means of theorising place and landscape. We do this for two interconnected reasons. First, dwelling has come to the fore recently as an approach to nature, place, and landscape, but we argue that further development of this idea is required in order to address issues relating to romantic views of places, authenticity, localness, and the way we ‘see’ landscapes. Second, we turn to the notion of dwelling to develop interconnected views of the world which can still retain a notion of place, a key but problematic concept within geography, landscape studies, and environmental thinking. In particular, we seek to develop ideas of place within the context of actor network theory. We explore the notion of dwelling in Heidegger and as adapted by Ingold, and we trace how dwelling has been deployed subsequently in studies of landscape and place. We then develop a more critical appreciation of dwelling in the context of an orchard in Somerset which we have researched as a place of hybrid constructions of culture and nature.
Performing Economic Geography: Two Men, Two Books, and a Cast of Thousands
Authors: Barnes Trevor J
Published: August 2002

In this paper I use the notion of performance, especially as it has been theorized within the science studies literature, to begin to make sense of the history and continuing practices of economic geography. I argue that not only humans perform, but also objects. In this paper, I focus on the performance of books, and in particular, textbooks, or as Bruno Latour calls them, ‘immutable mobiles’. I argue that textbooks bring four attributes to their performance: they travel easily over distance, thereby bringing their message to a geographically diffuse audience; they allow for ‘an optical and semiotic homogeneity’, that is, they take quite different pieces of the world, and bring them together, manipulating them and controlling them, on the same page; they represent an obligatory passage point in the sense that once they are accepted as the standard summary of a field they are necessarily acknowledged by successors; and finally, their effectiveness is in part a consequence of their rhetoric—defined as the ability to draw together and integrate within the text a wide range of sources and authors. These arguments about the performance of textbooks are illustrated by two case studies. The first is George G Chisholm's Handbook of Commercial Geography, published in 1889, which helps launch economic geography as an academic discipline within Anglo-America. The second is Peter Haggett's Locational Analysis in Human Geography, published in 1965, which in many ways codifies the quantitative and theoretical revolution that first emerged in the United States in the late 1950s.
Regional Subjection and Becoming
Authors: Gibson Katherine
Published: August 2002

This paper is motivated by a very current concern which is: how might subjects located in a predominantly single-industry resource region that has been devastated by processes of rationalization and privatization think about new regional economic futures when subjection to the Economy appears to be the most powerful and present determinant of their contemporary identity? In an attempt to provide some answers to this question I juxtapose three different modes of exploration and evidence: discussion of contemporary experiences of subjection as narrated by members of the Latrobe Valley community, analysis of historical documents that represent moments when specific forms of subjection first became embedded in practices of governmentality in the Valley, and speculations on the relations between being and becoming by social theorists Judith Butler and William Connolly. An analysis of selected techniques of governmentality affords some insights into how the Economy became the ultimate ‘real’ in the Valley whereas the Region has always figured as a ‘construction’. And encouraged by Butler's and Connolly's work on the possibilities and politics of becoming some glimpses of new regional economic becomings are caught.
Does Time-Shrinking Take Place in Visual Temporal Patterns?
Authors: Arao Hiroshi , Suetomi Daigoh , Nakajima Yoshitaka
Published: August 2002

The duration of a short empty time interval (typically shorter than 300 ms) is often underestimated when it is immediately preceded by a shorter time interval. This illusory underestimation—time-shrinking—had been studied only with auditory temporal patterns. In the present study, we examined whether similar underestimation would take place with visual temporal patterns. It turned out that underestimation of the same kind takes place also in the visual modality. However, a considerable difference between the auditory and the visual modalities appeared. In the auditory modality, it had been shown that the amount of underestimation decreased for preceding time intervals longer than 200 ms. In the present study, the underestimation increased when the preceding time interval varied from 160 to 400 ms. Furthermore, the differences between the two neighbouring intervals which could cause this underestimation had always been in a fixed range in the auditory modality. In the visual modality, the range was broader when the intervals were longer. These results were interpreted in terms of an assimilation process in light of the processing-time hypothesis proposed by Nakajima (1987 Perception16 485–520) in order to explain an aspect of empty-duration perception.
From Image Segmentation to Anti-Textons
Authors: van Tonder Gert J , Ejima Yoshimichi
Published: August 2002

We apply the ‘patchwork engine’ (PE; van Tonder and Ejima, 2000 Neural Networks forthcoming) to encode spaces between textons in an attempt to find a suitable feature representation of anti-textons [Williams and Julesz, 1991, in Neural Networks for Perception volume 1: Human and Machine Perception Ed. H Wechsler (San Diego, CA: Academic Press); 1992, Proceedings of the National Academy of Sciences of the USA89 6531–6534]. With computed anti-textons it is possible to show that tessellation and distribution of anti-textons can differ from that of textons depending on the ratio of texton size to anti-texton size. From this we hypothesise that variability of anti-textons can enhance texture segregation, and test our hypothesis in two psychophysical experiments. Texture segregation asymmetry is the topic of the first test. We found that targets on backgrounds with regular anti-textons segregate more strongly than on backgrounds with highly variable anti-textons. This neatly complements other explanations for texture segregation asymmetry (eg Rubenstein and Sagi, 1990 Journal of the Optical Society of America A7 1632–1643). Second the relative significance of textons and anti-textons in human texture segregation is investigated for a limited set of texture patterns. Subjects consistently judged a combination of texton and anti-texton gradients as more conspicuous than texton-only gradients, and judged texton-only gradients as being more conspicuous than anti-texton-only gradients. In the absence of strong texton gradients the regularity versus irregularity of anti-textons agrees with perceived texture segregation. Using PE outputs as anti-texton features thus enabled the conception of various useful tests on texture segregation. The PE is originally intended as a general image segmentation method based on symmetry axes. With this paper we therefore hope to relate anti-textons with visual processing in a wider sense.
Imperfect Invariance to Object Translation in the Discrimination of Complex Shapes
Authors: Dill Marcus , Edelman Shimon
Published: August 2002

The positional specificity of short-term visual memory for a variety of 3-D shapes was investigated in a series of ‘same’/‘different’ discrimination experiments, with computer-rendered stimuli displayed either at the same or at different locations in the visual field. For animal-like shapes, we found complete translation invariance, regardless of the interstimulus similarity, and irrespective of direction and size of the displacement (experiments 1 and 2). Invariance to translation was obtained also with animal-like stimuli that had been ‘scrambled’ by randomizing the relative locations of their parts (experiment 3). The invariance broke down when the stimuli were made to differ in their composition, but not in the shapes of the corresponding parts (experiments 4 and 5). We interpret this pattern of findings in the context of several current theories of recognition, focusing in particular on the issue of the representation of object structure.
Integration Biases in the Ouchi and other Visual Illusions
Authors: Mather George
Published: August 2002

A texture pattern devised by the Japanese artist H Ouchi has attracted wide attention because of the striking appearance of relative motion it evokes. The illusion has been the subject of several recent empirical studies. A new account is presented, along with a simple experimental test, that attributes the illusion to a bias in the way that local motion signals generated at different locations on each element are combined to code element motion. The account is generalised to two spatial illusions, the Judd illusion and the Zöllner illusion (previously considered unrelated to the Ouchi illusion). The notion of integration bias is consistent with recent Bayesian approaches to visual coding, according to which the weight attached to each signal reflects its reliability and likelihood.
People Don'T Keep Their Heads Still When Looking to One Side, and Other People Can Tell
Authors: Doherty Martin J , Anderson James R
Published: August 2002

Twenty pairs of photographs were made of adults looking 25° to the left and 25° to the right while attempting to face forwards. The eye regions of each photograph were concealed. Twenty adults attempted to sort each pair into left-looking and right-looking pictures. They were successful 65% of the time, p < 0.001. This suggests models have difficulty looking to one side without a perceptible head turn or comparable facial cue. This previously unrecognised phenomenon has implications for research on detection of gaze.
Perception of Partly Occluded Figures by Baboons (Papio Papio)
Authors: Deruelle Christine , Barbet Isabelle , Dépy Delphine , Fagot Joël
Published: August 2002

Comparative literature provides conflicting findings whether animals experience amodal completion. Five experiments were conducted to verify if baboons perceive partly occluded objects as complete. The first three experiments used a go/no-go procedure and a video monitor for stimulus presentation. These experiments failed to reveal amodal completion, suggesting that the stimuli were processed as 2-D images rather than 3-D objects. In contrast, completion was demonstrated in a fourth experiment with cardboard stimuli in a two-alternative forced-choice (2AFC) discrimination task presented in a Wisconsin General Test Apparatus. Although in experiment 5 the same 2AFC procedure was used as in experiment 4, completion was absent when the stimuli were shown with a computer graphic system. The results suggest that baboons share with humans the ability for amodal completion, but also underline some procedural factors that might affect the elicitation of this capacity.
The Minimum Temporal Thresholds for Motion Detection of Grating Patterns
Authors: Tayama Tadayuki
Published: August 2002

The minimum temporal thresholds for absolute motion detection were measured for sinusoidal grating patterns in foveal vision. Test patterns of relatively low temporal frequencies and low velocities were examined. The thresholds clearly decreased with test velocities rather than with test temporal frequencies. Modified velocity–time reciprocity was observed (ie the relationship between test velocity and temporal thresholds was described by a simple equation including two constants which indicate temporal and spatial limits). The temporal constant was about 35 ms and the spatial constant was about 1 min of arc. These constants are thought to provide the basic constraints on motion detection.
Cognitive Suppression of Tilt Sensations during Linear Horizontal Self-Motion in the Dark
Authors: Wertheim Alex H , Mesland Barbara S , Bles Willem
Published: August 2002

On the basis of models of otolith functioning, one would expect that, during sinusoidal linear self-motion in darkness, percepts of body tilt are experienced. However, this is normally not the case, which suggests that the otoliths are not responsive to small deviations from the vertical of the gravito-inertial force vector acting on them. Here we show that this is incorrect. Subjects usually know on what kind of linear motion device they are (going to be) moved, having seen it prior to experimentation. This may result in a cognitive suppression of such otolith responses. In the present study, subjects were kept completely unaware of how they were moved and were asked to report on how they thought they moved. About 50% of the reports included tilt percepts almost immediately. It is concluded that this reveals the presence of otolith responsiveness to even small and short-lived deviations of the gravito-inertial force vector from verticality, a responsiveness which is suppressed when (prior) cognitions exist that the motion path is purely in the horizontal plane.
A Prior for Global Convexity in Local Shape-from-Shading
Authors: Langer Michael S , Bülthoff Heinrich H
Published: August 2002

To solve the ill-posed problem of shape-from-shading, the visual system often relies on prior assumptions such as illumination from above or viewpoint from above. Here we demonstrate that a third prior assumption is used—namely that the surface is globally convex. We use complex surface shapes that are realistically rendered with computer graphics, and we find that performance in a local-shape-discrimination task is significantly higher when the shapes are globally convex than when they are globally concave. The results are surprising because the qualitative global shapes of the surfaces are perceptually unambiguous. The results generalise findings such as the hollow-potato illusion (Hill and Bruce 1994 Perception23 1335–1337) which consider global shape perception only.
Merino wool contamination from rearing of Damara crossbred lambs
Authors: Fleet M. R. , Turk J. A. , Cottell M. A. , Keynes G. N.
Published: August 2002

Recent importations and promotion of Damara sheep has raised concerns and
debate about potential for Merino wool contamination. This project examined
Merino ewe wool contamination arising from the mating of Damara rams and
rearing of Damara crossbred lambs. Shirley-blended core samples from 3
commercial greasy wool sale lots known to involve Merino ewes shorn with
Damara crossbred lambs at foot (2 lots), or shorn 3 weeks after weaning, were
assessed. Contaminant fibres were above commercial expectations for Merino
wool and present in every core sample measured. There was no significant
difference found between these sale lots. From an experimental flock,
composites of fleece samples were carded and the effects of mating or rearing
alone assessed. No detectable increase of pigmented or heavily medullated
fibres, above very low background levels, were detected among the Merino ewes
mated to Damara rams (1 ram per 65 ewes). However, high concentrations of
contaminant fibres were found in the Merino ewe wool at weaning of their
Damara crossbred lambs and also 3.5 months after weaning; with reduced levels
post-weaning. The management strategy of restricting wool exposure to mating
effects alone may offer advantage but delaying shearing of ewes after weaning
to reduce the contaminant fibre burden was, in this case, not sufficient to
overcome potential concerns for wool processing. However, in view of the many
potential contributing factors, actual contamination may vary widely between
cases and require the advancement of presale measurement to gain buyer
confidence and accurate appraisals.
Restricted branching narrow-leafed lupin. 3. Poor establishment
Authors: Dracup M. , Thomson R. , Galwey N.
Published: August 2002

Establishment of restricted branching narrow-leafed lupins
(Lupinus angustifolius L.) is often poorer than that of
the normal branching counterparts. This study focused on establishment of the
cultivars Tallerack and Merrit, as representative of restricted and normal
branching lupins, respectively. Establishment from seeds of both genotypes
harvested manually was high, but machine harvesting decreased establishment,
at some sites markedly, and generally more so in Tallerack than in Merrit.
Establishment problems were related to germination and not emergence or
seedling vigour. A similar contrast was found when seeds were harvested from
several near-isogenic pairs of restricted- and normal branching genotypes. The
basis of the generally greater sensitivity of the restricted branching
genotypes to harvest damage, and the interaction with environment is not
clear. It is not related to differences between genotypes in the seed size,
proportion of hull in seeds or seed moisture content, but hull composition and
embryo morphology warrant further study. Irrespective of its basis, higher
harvest damage to seeds of restricted branching genotypes is likely to be
avoided by minimising harvester drum speeds and harvesting at higher seed
moisture concentrations.
Agaricales in Australasia
Authors: Grgurinovic Cheryl A.
Published: August 2002

The estimated number of species of Agaricales from Australasia is discussed.
Recent research on the same genera or families in different parts of
Australasia is compared to assess species’ numbers and levels of
endemicity. How these taxa fit into current classifications is also discussed.