bluuebunny/crossref_metadata_2025 huggingface dataset:
Aspects of the Search for Neural Mechanisms of Memory
Authors: Rosenzweig Mark R.
Published: July 2002

The search for neural mechanisms of memory has been under way for more than a century. The pace quickened in the 1960s when investigators found that training or differential experience leads to significant changes in brain neurochemistry, anatomy, and electrophysiology. Many steps have now been identified in the neurochemical cascade that starts with neural stimulation and ends with encoding information in long-term memory. Applications of research in this field are being made to child development, successful aging, recovery from brain damage, and animal welfare. Extensions of current research and exciting new techniques promise novel insights into mechanisms of memory in the decades ahead.
US Social Policy in Comparative and Historical Perspective: Concepts, Images, Arguments, and Research Strategies
Authors: Amenta Edwin , Bonastia Chris , Caren Neal
Published: July 2002

In this article we review theory and comparative and historical research on US social policy. We discuss first the conceptual frameworks used to think about social policy, the changing images of American social policy implied by these different frameworks, and the questions they raise. From there we examine the arguments offered to answer questions about US social policy as well as the research strategies and evidence used to appraise the arguments. We address work that situates US social policy in comparative perspective as well as work that examines the development of American social policy historically or across states. Although many lines of argumentation have some empirical support, we find that some lines of political and institutional analyses provide the best supported answers to the questions and the greatest potential for wide usage in comparative and historical studies. We conclude that scholars would do well not to treat American social policy as so exceptional as to require separate images, explanations, and approaches. We suggest promising new lines of empirical inquiry prompted by new conceptualizations of social policy and other developments in this literature.
Sociological Miniaturism: Seeing the Big Through the Small in Social Psychology
Authors: Stolte John F. , Alan Gary , Cook Karen S.
Published: July 2002

The distinctive contribution of sociological social psychology can be referred to as sociological miniaturism, a way of interpreting social processes and institutions that is microsociological more than it is psychological. We argue that social psychology of this variety permits the examination of large-scale social issues by means of investigation of small-scale social situations. The power of this approach to social life is that it permits recognition of the dense texture of everyday life, permits sociologists to understand more fully a substantive domain, and permits interpretive control. In the chapter we provide examples of this approach from two quite distinct theoretical orientations: symbolic interactionism and social exchange theory. We discuss the ways in which the study of two substantive topics, social power and collective identity, using these perspectives can be informed by closer collaboration between theorists within sociological social psychology. In the end it is our hope that pursuing such integrative theoretical and methodological efforts will produce a more complete understanding of important social phenomena. We offer sociological miniaturism as a promising vehicle for advancing the earlier call for greater mutual appreciation of and rapprochement between diverse lines of social psychological work in sociology.
A Self-Defining Game for One Player: On the Nature of Creativity and the Possibility of Creative Computer Programs
Authors: Cohen Harold
Published: July 2002

The AARON program has been generating original artworks for almost 30 years, but is denied by its own author to be creative. The author characterizes creativity as a directed movement towards an illdefined but strongly felt end-state for the individual's work as a whole, not as a characteristic of any single work and profoundly knowledge-based in the sense of externalizing the individual's internal worldmodel and system of belief. He suggests that a creative program would be one that was able to modify the belief-based criteria that inform the rule-base in which expert knowledge is represented, not one that is able simply to modify the rule-base itself.
The Interaction of Knowledge Sources in Word Sense Disambiguation
Authors: Stevenson Mark , Wilks Yorick
Published: July 2002

Word sense disambiguation (WSD) is a computational linguistics task likely to benefit from the tradition of combining different knowledge sources in articial intelligence research. An important step in the exploration of this hypothesis is to determine which linguistic knowledge sources are most useful and whether their combination leads to improved results. We present a sense tagger which uses several knowledge sources. Tested accuracy exceeds 94% on our evaluation corpus.

Our system attempts to disambiguate all content words in running text rather than limiting itself to treating a restricted vocabulary of words. It is argued that this approach is more likely to assist the creation of practical systems.
Electrophysiological Correlates of Phonological Processing: A Cross-linguistic Study
Authors: Dehaene-Lambertz G. , Dupoux E. , Gout A.
Published: July 2002

It is well known that speech perception is deeply affected by the phoneme categories of the native language. Recent studies have found that phonotactics, i.e., constraints on the cooccurrence of phonemes within words, also have a considerable impact on speech perception routines. For example, Japanese does not allow (nonasal) coda consonants. When presented with stimuli that violate this constraint, as in / ebzo/, Japanese adults report that they hear a /u/ between consonants, i.e., /ebuzo/. We examine this phenomenon using event-related potentials (ERPs) on French and Japanese participants in order to study how and when the phonotactic properties of the native language affect speech perception routines. Trials using four similar precursor stimuli were presented followed by a test stimulus that was either identical or different depending on the presence or absence of an epenthetic vowel /u/ between two consonants (e.g., “ebuzo ebuzo ebuzo—ebzo”). Behavioral results confirm that Japanese, unlike French participants, are not able to discriminate between identical and deviant trials. In ERPs, three mismatch responses were recorded in French participants. These responses were either absent or significantly weaker for Japanese. In particular, a component similar in latency and topography to the mismatch negativity (MMN) was recorded for French, but not for Japanese participants. Our results suggest that the impact of phonotactics takes place early in speech processing and support models of speech perception, which postulate that the input signal is directly parsed into the native language phonological format. We speculate that such a fast computation of a phonological representation should facilitate lexical access, especially in degraded conditions.
The Role of Familiar Size in the Control of Grasping
Authors: Marotta J. J. , Goodale M. A.
Published: July 2002

The present study examined whether the learned pictorial depth cue of “familiar size” could be used to plan a reaching and grasping movement in the absence of binocular vision. Sixteen right-handed subjects were presented with two different arrays, under monocular and binocular viewing conditions, in which a range of different “grasp-sized” spheres that were lit from within could be presented in an otherwise darkened environment. In the “familiar-size” presentation array, only one “standard” sized sphere was presented, which gave subjects an opportunity to learn the relationship between the standard sphere's retinal image size and its distance. In the “multiple” spheres presentation array, subjects could not learn such a relationship because on any one trial, one of four different sphere sizes could be present. In a second experiment, the effects of this paradigm on six subjects' perceptual reports of distance were examined by having subjects slide their index fingers apart along a horizontal rod to indicate the estimated distance of the spheres. When familiar size could not be used as a cue to distance, subjects produced more on-line corrections in their reaching and grasping movements to the standard-sized spheres—but only under monocular viewing conditions. It appears that subjects are able to exploit the learned relationship between an object's distance and its projected retinal image size to help program and control reaching and grasping movements when binocular vision is not available. Although the influence of familiar size on subjects' perceptual estimates is less clear, it is clear that subjects' perceptual estimates show poor absolute scaling for distance. This result further supports the notion that under normal viewing conditions the visuomotor system uses binocular information to program and control manual prehension, but is able to use pictorial information when binocular vision is denied.
Hemispheric and Facial Asymmetry: Faces of Academe
Authors: Smith William M.
Published: July 2002

Facial asymmetry (facedness) of selected academic faculty members was studied in relation to brain asymmetry and cognitive specialization. Comparisons of facedness were made among humanities faculty (H), faculty members of mathematics and physics (M-P), psychologists (P), and a group of randomly selected individuals (R). Facedness was defined in terms of the relative sizes (in square centimeters) of the two hemifaces.

It was predicted that the four groups would show differences in facedness, namely, H, right face bias; M-P, left face bias; P, no bias; and R, no bias. The predictions were confirmed, and the results interpreted in terms of known differences in hemispheric specialization of cognitive functions as they relate to the dominant cognitive activity of each of the different groups.

In view of the contralateral control of the two hemifaces (below the eyes) by the two hemispheres of the brain, the two sides of the face undergo differential muscular development, thus creating facial asymmetry. Other factors, such as gender, also may affect facial asymmetry.

Suggestions for further research on facedness are discussed.
Cortical Regions Associated with Perceiving, Naming, and Knowing about Colors
Authors: Chao Linda L. , Martin Alex
Published: July 2002

Positron emission tomography (PET) was used to investigate whether retrieving information about a specific object attribute requires reactivation of brain areas that mediate perception of that attribute. During separate PET scans, subjects passively viewed colored and equiluminant gray-scale Mondrians, named colored and achromatic objects, named the color of colored objects, and generated color names associated with achromatic objects. Color perception was associated with activations in the lingual and fusiform gyri of the occipital lobes, consistent with previous neuroimaging and human lesion studies. Retrieving information about object color (generating color names for achromatic objects relative to naming achromatic objects) activated the left inferior temporal, left frontal, and left posterior parietal cortices, replicating previous findings from this laboratory. When subjects generated color names for achromatic objects relative to the low-level baseline of viewing gray-scale Mondrians, additional activations in the left fusi-form/lateral occipital region were detected. However, these activations were lateral to the occipital regions associated with color perception and identical to occipital regions activated when subjects simply named achromatic objects relative to the same low-level baseline. This suggests that the occipital activa-tions associated with retrieving color information were due to the perception of object form rather than to the top-down influence of brain areas that mediate color perception. Taken together, these results indicate that retrieving previously acquired information about an object's typical color does not require reactivation of brain regions that subserve color perception.
Extraction of Specific Signals with Temporal Structure
Authors: Barros Allan Kardec , Cichocki Andrzej
Published: July 2002

In this work we develop a very simple batch learning algorithm for semi-blind extraction of a desired source signal with temporal structure from linear mixtures. Although we use the concept of sequential blind extraction of sources and independent component analysis, we do not carry out the extraction in a completely blind manner; neither do we assume that sources are statistically independent. In fact, we show that the a priori information about the autocorrelation function of primary sources can be used to extract the desired signals (sources of interest) from their linear mixtures. Extensive computer simulations and real data application experiments confirm the validity and high performance of the proposed algorithm.
A Bayesian Approach to the Stereo Correspondence Problem
Authors: Read Jenny C. A.
Published: July 2002

I present a probabilistic approach to the stereo correspondence problem. Rather than trying to find a single solution in which each point in the left retina is assigned a partner in the right retina, all possible matches are considered simultaneously and assigned a probability of being correct. This approach is particularly suitable for stimuli where it is inappropriate to seek a unique partner for each retinal position—for instance, where objects occlude each other, as in Panum's limiting case. The probability assigned to each match is based on a Bayesian analysis previously developed to explain psychophysical data (Read, 2002). This provides a convenient way to incorporate constraints that enable the ill-posed correspondence problem to be solved. The resulting model behaves plausibly for a variety of different stimuli.
Probability Density Methods for Smooth Function Approximation and Learning in Populations of Tuned Spiking Neurons
Authors: Sanger Terence David
Published: July 2002

This article proposes a new method for interpreting computations performed by populations of spiking neurons. Neural firing is modeled as a rate-modulated random process for which the behavior of a neuron in response to external input can be completely described by its tuning function. I show that under certain conditions, cells with any desired tuning functions can be approximated using only spike coincidence detectors and linear operations on the spike output of existing cells. I show examples of adaptive algorithms based on only spike data that cause the underlying cell-tuning curves to converge according to standard supervised and unsupervised learning algorithms. Unsupervised learning based on principal components analysis leads to independent cell spike trains. These results suggest a duality relationship between the random discrete behavior of spiking cells and the deterministic smooth behavior of their tuning functions. Classical neural network approximation methods and learning algorithms based on continuous variables can thus be implemented within networks of spiking neurons without the need to make numerical estimates of the intermediate cell firing rates.
Synchrony and Desynchrony in Integrate-and-Fire Oscillators
Authors: Campbell Shannon R. , Wang DeLiang L. , Jayaprakash Ciriyam
Published: July 2002

Due to many experimental reports of synchronous neural activity in the brain, there is much interest in understanding synchronization in networks of neural oscillators and its potential for computing perceptual organization. Contrary to Hopfield and Herz (1995), we find that networks of locally coupled integrate-and-fire oscillators can quickly synchronize. Furthermore, we examine the time needed to synchronize such networks. We observe that these networks synchronize at times proportional to the logarithm of their size, and we give the parameters used to control the rate of synchronization. Inspired by locally excitatory globally inhibitory oscillator network (LEGION) dynamics with relaxation oscillators (Terman & Wang, 1995), we find that global inhibition can play a similar role of desynchronization in a network of integrate-and-fire oscillators. We illustrate that a LEGION architecture with integrate-and-fire oscillators can be similarly used to address image analysis.
Evaluation of the Effects of a Head-mounted Display on Ocular Accommodation
Authors: Neveu Charles , Blackmon Ted , Stark Lawrence
Published: July 2002

We evaluated a commercially produced head-mounted display (HMD) to determine its short-term effects on human ocular accommodation. Thirteen subjects (seven men and six women, ranging from 13 to 44 years old) were tested for changes in a number of parameters before and after viewing a full-length movie (approximately two hours) on a HMD. As a control, subjects were also tested before and after viewing a movie on a high-quality NTSC color television, and also before and after a one-hour intermission. Accommodation dynamics and range were measured. Data showed wellknown trends due to subject age. Only one statistically significant change was found: a slight increase in the latency of relaxation accommodation after HMD viewing.
Virtual Workbench: Near-Field Virtual Environment System with Applications
Authors: Wiegand Thomas E. von , Schloerb David W. , Sachtler W. L.
Published: July 2002

A prototype near-field virtual environment system is described that incorporates a CrystalEyes stereoscopic display (viewed in a mirror), a PHANToM manipulandum, and a stereo auditory display. The apparatus, which was designed to achieve registration of three sensory modalities (visual, haptic, and auditory), has a wide range of applications and has been used for both psychophysics and training research. Calibration-verification experiments are described in which human subjects positioned a physical probe attached to the manipulandum so that it appeared to coincide with a visual target on the stereoscopic display. The readings from the manipulandum and the calculated positions of the targets corresponded roughly within ± 0.5 cm over a large volume, although differences greater than 1 cm were observed near the sides of the workspace. The calibration of the manipulandum was tested independently on the z axis (running through the center of the workspace), and the perceived depth of the targets (probe z coordinate) was found to agree with the calculated depth within the accuracy of the measurements (± 0.4 cm). Some subjects had poorer positioning resolution when the visual target was far from the plane of the display screen (although their mean response was unaffected), and we hypothesize that this may have been caused by the different levels of accommodation that were needed to view the physical probe and the displayed target.
Linkage Problem, Distribution Estimation, and Bayesian Networks
Authors: Pelikan Martin , Goldberg David E. , Cantú-Paz Erick
Published: July 2002

This paper proposes an algorithm that uses an estimation of the joint distribution of promising solutions in order to generate new candidate solutions. The algorithm is settled into the context of genetic and evolutionary computation and the algorithms based on the estimation of distributions. The proposed algorithm is called the Bayesian Optimization Algorithm (BOA). To estimate the distribution of promising solutions, the techniques for modeling multivariate data by Bayesian networks are used. The BOA identifies, reproduces, and mixes building blocks up to a specified order. It is independent of the ordering of the variables in strings representing the solutions. Moreover, prior information about the problem can be incorporated into the algorithm, but it is not essential. First experiments were done with additively decomposable problems with both nonoverlapping as well as overlapping building blocks. The proposed algorithm is able to solve all but one of the tested problems in linear or close to linear time with respect to the problem size. Except for the maximal order of interactions to be covered, the algorithm does not use any prior knowledge about the problem. The BOA represents a step toward alleviating the problem of identifying and mixing building blocks correctly to obtain good solutions for problems with very limited domain information.
Exploring the Relationship between Neutral and Selective Mutations in Cancer
Authors: Maley Carlo C. , Forrest Stephanie
Published: July 2002

The transformation of normal cells into cancerous cells is an evolutionary process. Populations of precancerous cells reproduce, mutate, and compete for resources. Some of these mutations eventually lead to cancer. We calculate the probability of developing cancer under a set of simplifying assumptions and then elaborate these calculations, culminating in a simple simulation of the cell dynamics. The agent-based model allows us to examine the interactions of mutations critical for the development of cancer that are either evolutionarily neutral or selective. We can also examine the interaction of these mutations with a “mutator phenotype” derived from mutations that raise the mutation rate for the entire cell. The simulations suggest that there must be at least two selectively neutral mutations necessary for the development of cancer and that preventive treatments will be most effective when they increase this number. The model also suggests that selective mutations facilitate the development of cancer, so that the more selective mutations necessary for the development of cancer, the greater the chance of developing it.
Product‐Oriented Environmental Management: Lessons from Total Quality Management
Authors: de Bakker Frank G. A.
Published: July 2002

Environmental management issues are becoming ever more prominent in business, and their focus is broadening from process orientation toward product orientation. Until now, little attention has been paid to an organizational focus on the environmental performance of products. This article therefore considers product‐oriented environmental management (POEM), an approach to organizing and operating a firm in such a way that improving the environmental performance of its products and processes becomes an integrated part of operations and strategy. First, the POEM concept is introduced. Because this concept addresses some issues similar to those of quality management, the possibilities of using insights from total quality management (TQM) in developing POEM are investigated. Based on an overview of the literature and conceptual studies of TQM, a coherent set of several elements are described that can contribute to the organization of POEM. These elements are grouped in a framework, the POEM matrix, which can be used to guide research within this emerging area of organizing for the environmental characteristics of products. This matrix could also provide guidance to practitioners by delivering an integrated perspective on the organizational elements that are conducive to organizing POEM. An example from case study research in the chemical industry illustrates such an application of the matrix.
Consumption and its Externalities: Where Economy Meets Ecology
Authors: Princen Thomas
Published: July 2002

If social scientists are going to make a contribution to environmental policy-making that is commensurate with the severity of biophysical trends, they must develop analytic tools that go beyond marginal improvement and a production focus where key actors escape responsibility via distanced commerce and the black box of consumer sovereignty. One means is to construct an ecologically informed “consumption angle” on economic activity. The first approach is to retain the prevailing supply-demand dichotomy and address the externalities of consumption and the role of power in consuming. The second approach is to construe all economic activity as “consuming,” as “using up.” This approach construes material provisioning in the context of hunter/gathering, cultivation, and manufacture and then develops three interpretive layers of excess consumption: background consumption, overconsumption, and misconsumption. An example from timbering illustrates how, by going up and down the decision chain, the consumption angle generates questions about what is consumed and what is put at risk. Explicit assignment of responsibility for excess throughput becomes more likely.
ON OTTOMAN JUSTICE: INTERPRETATIONS IN CONFLICT (1600 - 1800)
Authors: Ergene Bogaç
Published: July 2002

This essay investigates the ways in which the notion of "justice" was utilized as a mechanism of political legitimization in the early-modern Ottoman Empire. I claim that there existed alternative definitions of justice and that these were instrumental in the struggle between the central government and those official and unofficial power-holders in the administrative and geographical peripheries of the empire. According to the specialized terminology of the Ottoman administrative system, "justice" was the protection of the rural and urban producers against abuses of the military elite. This definition highlighted the personal benevolence of the ruler who claimed to be the sole protector of the weak against oppression. On the other hand, at least some segments of the ruling elite insisted on representing justice as the recognition of the mutual rights and obligations of the sultan and his "servants." Justice, in this context, referred to the protection of privileges and entitlements of those who were thought to deserve them. While using a variety of sources - including treatises on government and ethics composed by the Ottoman literati, documents from regional court records and correspondence between the imperial center and the officials in the provinces - my primary focus is on Evliya Çelebi's seventeenth-century travel-book, Seyahatname, and a well-known seventeenth century chronicle, Tarih-i Naima.
HOW MONOTHEISTIC IS MANI'S DUALISM?
Authors: Scibona Concetta Giuffré
Published: July 2002

A passage from the Codex Manichaicus Coloniensis (CMC 66,4) has led to a series of reflections and opinions from scholars on the dualistic or monotheistic nature of the original form of Manichaeism. This essay outlines the status quaestionis and then goes on to examine, on the basis of texts and using the historico-comparative method, the analogies and differences between the historical "types" of monotheism and dualism (Judaeo-Christianity, Mazdaism, gnosticism), and Manichaeism, which is related to them in different ways and in varying degrees. Taking position in this debate between minimalist and maximalist points of view, the author attempts to identify the parameters of this original religious creation, and argues that theological monotheism and ontological dualism were, from its birth, coherent elements in its peculiar gnostic conception of reality.
Beyond Anecdotes: An Empirical Study of "Anthropomorphism"
Authors: Morris Paul , Fidler Margaret , Costall Alan
Published: July 2002

The status of "anthropomorphic" descriptions of animals in terms of intentions and emotions has been generally regarded as a prescriptive methodological concern. In contrast, in the study of human social psychology the nature of psychological descriptions of other people has been approached as a substantive empirical issue. Following this lead, the present study investigated the nature of people's descriptions of short videotaped episodes of animal behavior. The descriptions obtained were predominantly anthropomorphic and structured according to a limited set of "event units" whose psychological meaning was highly consistent across the observers. In common with many social psychologists we conclude that consistency of anthropomorphic description suggests that meaning is specified within the structure of behavior.
Vocal repertoire and effect of advertisement call intensity on calling behaviour in the West African tree frog, Leptopelis viridis
Authors: Steffen Jan , Grafe T. Ulmar , Stoll Carolin
Published: July 2002

The vocal repertoire of the West African tree frog Leptopelis viridis was investigated in the Comoé National Park, Ivory Coast. Leptopelis viridis had a complex vocal repertoire consisting of short clicks, multinote clicks, trills, and soft calls. Most calls produced were short advertisement clicks. Soft calls were emitted during agonistic interactions between males suggesting that they function as aggressive calls. In contrast, multinote calls and trills were emitted when advertisement call rate was high suggesting that these calls are used by males to increase their attractiveness to females. Even at high densities males were spaced widely with a median nearest neighbour distance of 4.8 m. We also examined the effects of increased sound level of advertisement calls on calling behaviour. Playback experiments using synthetic clicks showed that males increased the proportion of aggressive calls as the stimulus intensity was increased. Males typically responded with aggressive calls when playback levels exceeded 82 dB (re 20 μPa). At high playback levels males either aggressively approached the speaker or silently retreated.
A posthatching developmental staging table for the long-toed salamander, Ambystoma macrodactylum krausei
Authors: Russell Anthony , Watson Sheri
Published: July 2002

A posthatching developmental staging table for the larval phase of an ambystomatid salamander is provided for the first time. Stage boundaries are based upon limb development prior to the metamorphic transition and upon gill resorption during metamorphosis. Comparison to other published staging tables for salamanders of other families and anecdotal accounts of other ambystomatids is made, and similarities and differences are noted. These comparative data suggest that limb development may differ between species of Ambystoma in terms of the relative timing of hindlimb and forelimb morphogenesis.
EFFECT OF GREAT SPOTTED CUCKOO PRESENCE ON MAGPIE REJECTION BEHAVIOUR
Authors: Soler Manuel , Soler Juan Jose , Moller Anders Pape
Published: July 2002

Soler & Moller (1990) reported that egg rejection of great spotted cuckoo Clamator glandarius eggs by magpies Pica pica varies between populations depending on the duration of sympatry. Here, we test experimentally the idea that differences in ejection rates between areas of presumably different duration of sympatry could be due to a conditional response by magpies to the presence of adult parasites near the nest. The rate of ejection of mimetic cuckoo egg models was identical in both treatment groups, independently of whether or not the cuckoo was presented at the same time as the model egg. Thus, we conclude that the presence of a great spotted cuckoo near the magpie nest does not increase the probability of egg rejection.
DEVELOPMENT OF VOCAL RESPONSES IN INFANT COTTON-TOP TAMARINS
Authors: Castro Nicole , Snowdon Charles
Published: July 2002

To examine the development of production, comprehension and usage of chirp vocalizations in infant cotton-top tamarins, we designed four experimental settings to elicit five of the eight chirp types of adult cotton-top tamarins. We tested non-reproductive adult pairs and family groups before and after the birth of infants. We observed responses of infants in family groups during the first 20 weeks following birth. The five chirp types were rarely given in control conditions, but each type occurred at significant levels among adults and subadults immediately following presentation of an appropriate stimulus. Each chirp type was specific to one experimental manipulation. We found no differences between non-reproductive pairs and families prior to the birth of infants, but two chirp types were produced at significantly lower rates following the birth of infants. Infants produced a form of chirp (prototype chirp) not seen in adults, but infants rarely produced adult forms of chirps. If an adult-appropriate chirp was produced by an infant in one session, there was a low probability of that chirp appearing in subsequent tests with the same infant. Infants used most frequently the form of chirp (D chirp) that was most frequently directed toward them by adults, and infants reduced their rates of prototype chirps following presentation of visual and auditory alarm stimuli. Although infant tamarins under 20 weeks of age appear unable to use adult types of chirps consistently, they did produce chirps with adult form, and they appeared to show some comprehension of chirps produced by adults.
DOMINANCE HIERARCHIES IN FEMALE MOUNTAIN GOATS: STABILITY, AGGRESSIVENESS AND DETERMINANTS OF RANK
Authors: Côté Steeve
Published: July 2002

To investigate the importance of dominance relationships in the social organization of large mammals, I studied the aggressive behaviour of marked adult female mountain goats (Oreamnos americanus) during four years in west-central Alberta, Canada. Despite large group size, the 38-45 adult females in the population were organized in a strong and very stable linear hierarchy. Social rank was strongly related to age and did not decrease for the oldest females. The presence of a kid did not affect the aggressive behaviour of females, suggesting that aggressiveness probably did not evolve for offspring defense in mountain goats. Initiators won most encounters, except when the receiver was an older female. When age was accounted for, body mass, horn length, and body size were not related to female rank. A new measure of aggressiveness, controlling for the number of opportunities for interactions, revealed that aggressiveness towards younger adult females increased with both age and social rank. On the other hand, age and social rank did not affect aggressiveness towards other females of the same age or older. Goats interacted more often with individuals of similar ranks than with individuals that were distant in the dominance hierarchy. Social rank of adult daughters was not related to the social rank of mothers. Although central positions in a group may decrease predation risk, dominant females did not occupy central positions more often than subordinates. Because age was the main determinant of rank, the only effective way to increase social rank was to survive.
DUET SINGING AND FEMALE CHOICE IN THE BUSHCRICKET PHANEROPTERA NANA
Authors: Tauber Eran , Cohen Dan , Greenfield Michael , Pener Meir Paul
Published: July 2002

the reliability with which females can assess male song at a distance and potential disadvantages of attracting multiple suitors. Laboratory trials indicated that only males receiving a high female response rate actually approach and mate with the female. Thus, this duet signalling system may be relatively resistant to intraspecific exploitation.
TENURE RELATED CHANGES IN WILD THOMAS'S LANGURS II: LOUD CALLS
Authors: Steenbeek Romy , Assink Peter , Wich Serge
Published: July 2002

In this paper, we investigate how the number and context of male loud calls of Thomas's langurs (Presbytis thomasi) change over a male's tenure, in relation to changes in the intensity of male mate competition and relative male strength. We also investigate how the calls' impact on the behavior of receivers varies over tenure phases. Thomas's langurs live in one-male multi-female groups; only males produce loud calls; both males and females disperse from their natal groups; female secondary dispersal is also common, and infanticide occurs. The life-span of a group is, as a rule, restricted to the tenure of its reproductive male (median tenure length is 72 months). Male tenure in bisexual groups was divided into three phases: the early phase (no infants yet), the stable middle phase, and the late phase (last year). Because AMBs remained after all females had left a male, they were treated as a fourth phase. We hypothesised that the tendency to answer another male's calls decreases with distance because a male will invest less when answering becomes less relevant. The tendency to respond to a loud call by an extra-group male indeed decreased with distance, which suggests that males invested less in (costly) calling behavior when the chance of an interaction with that male was low. Extra-group males seemed to recognise males of new groups: they did not discriminate between medium and far distances in answering calls from (relatively unfamiliar) early tenure males. We further hypothesised that an increase in male mate competition would result in more call bouts per day and a higher tendency to answer calls, which was not found. Males with a relatively low strength were expected to keep signalling their presence, but because this low strength includes a higher risk for females and infants, we expected females to avoid loud calling extra-group males. Males with a declining strength continued to signal their presence, as was expected, but they did reduce participation in dawn call bouts, which might be a particularly sensitive measure of their decreased strength. Extra-group males answered calls by males during their late tenure phase more often at medium and far distances, which shows that males recognised calls from late tenure males. Females' avoidance of calling extra-group males remained constant during the early and middle phase but increased during the late tenure phase, as was expected. AMB males clearly avoided males from bisexual groups: they never participated in dawn call bouts, they rarely started or answered calls and they travelled away from calling males. AMB males only answered a call bout in the case of a betweengroup conflict, when their position was already known. Hence, in Thomas's langurs, loud call behavior influenced male mate competition, and it varied in relation to changes in relative male strength.
THE RED GAPE OF THE NESTLING CUCKOO (CUCULUS CANORUS) IS NOT A SUPERNORMAL STIMULUS FOR THREE COMMON HOSTS
Authors: Noble  , Davies  , Hartley  , McRae
Published: July 2002

The bright red gape of the nestling common cuckoo Cuculus canorus has often been supposed to act as a supernormal stimulus to elicit provisioning from its foster parents. Parents of three main host species were tested for their response to their own nestlings with artificially reddened gapes. Robins, dunnocks and reed warblers allocated no more food to red-mouthed nestlings than to control nestlings in the same nest, and manipulations of the gape colour of whole broods of reed warblers revealed no effect on provisioning rates. Our data do not support the hypothesis that there is a universal parental preference for redder gapes in opennesting passerines, or that the bright red gape of nestling cuckoos has evolved to exploit parental preferences in these three hosts. We suggest that although mouth colour has little influence on the allocation of feeds resulting from sibling competition and begging intensity in these species, it may have a role under certain conditions.
Finding One's Mate in a King Penguin Colony: Efficiency of Acoustic Communication
Authors: Lengagne Thierry , Jouventin Pierre , Aubin Thierry
Published: July 2002

In the king penguin, during the three months of incubation and the brooding stage, members of a pair alternate care duties on land with foraging trips. Contrary to most of the species of birds that nest at a fixed location, the king penguin carries its egg on its feet during incubation. This allows the incubating parents to move in the colony. Brooding or incubating parents moved on average 4.4 meters between egg-laying and the end of the brooding stage. This movement in a group of thousands of other birds reduced the reliability of visual cues for recovering the pair mate during the change-over. We showed that the difficulty in relocating the mate was more important during the brooding stage than during incubating. We confirmed earlier findings that acoustic communication was the main mode of communication during a change-over, and showed that the omnidirectional properties of sound allowed birds to reach more than five hundred other birds with each emitted call. Our experiments proved that the communication system is performed at short or medium range. On average, the birds identified their mate at a distance of 8.8 m. Seventy percent of the birds started the acoustic search of their mate when the distance was shorter or equal to this discrimination range, and so acoustic communication is a particularly efficient strategy in the king penguin. Chez le manchot royal (Aptenodytes patagonicus) le male et la femelle participent tous deux a l'incubation et a l'elevage du poussin. Si en general les oiseaux possedent un nid dont la position fixe aide les deux partenaires a se retrouver lors des releves, le manchot royal est une des rares especes sans nid. En effet, l'adulte incube et protege son oeuf ou son poussin sur ses pattes ce qui lui permet de se deplacer dans la colonie. Nous avons mesure un deplacement moyen de 4.4 metres entre le moment de la ponte et la fin de l'elevage individuel. Ce deplacement parmis des milliers d'autres oiseaux morphologiquement semblables rend tous reperes visuels inutilisables lors des releves entre male et femelle. Pour se reconnaitre individuellement, les manchots utilisent une signature acoustique. Nous avons montre que les proprietes omnidirectionelles du son permettent au manchot qui cherche son partenaire de communiquer potentiellement avec plus de 500 oiseaux pour chaque chant emis. La degradation rapide de la signature lors de la propagation du signal dans la colonie ne permet pas une communication a longue distance: les oiseaux identifient le chant de leur partenaires a une distance moyenne de 8.8 metres. La majorite des manchots royaux (70%) commencent a chanter a une distance inferieure ou egale a la portee du signal ce qui revele une strategie de communication particulierement efficace.
PHYLOGENETIC ANALYSIS OF THE AMPHIPOD FAMILY BOGIDIELLIDAE S. LAT., AND REVISION OF TAXA ABOVE THE SPECIES LEVEL
Authors: Koenemann Stefan , Holsinger John
Published: July 2002

The increasing number of world-wide discoveries of subterranean amphipods, especially during the last two decades, has led to additions of numerous new taxa in the stygobiont family Bogidiellidae s. lat. To date, the family is composed of 23 genera and 11 subgenera, and approximately 110 described species. However, given the uneven quality of generic and subgeneric diagnoses in the literature, there is considerable confusion regarding the status of some of the taxa at these levels. Even the family itself lacks a clear definition. In order to gain a better knowledge of the phylogeny of this group, a cladistic analysis, employing both PAUP 3.0s and MacClade, was performed on the genera and subgenera currently assigned to the Bogidiellidae s. lat. Supported by the results of this analysis, the taxonomic structure of this group is completely revised above the species level. The revision excludes 5 genera from the family, all remaining subgenera are elevated to generic level. Four taxa are split, resulting in 5 new genera. The family Bogidiellidae now consists of 33 genera. Die wachsende Zahl weltweiter Neuentdeckungen von Grundwasser-Amphipoden, insbesondere wahrend der letzten zwei Jahrzehnte, erweiterte die Stygobiontenfamilie Bogidiellidae s. lat., um zahlreiche neue Taxa. Bis heute sind in der Familie etwa 110 beschriebene Arten in 23 Gattungen und 11 Untergattungen zusammengefasst. Aufgrund der unterschiedlichen Qualitat diagnostischer Beschreibungen herrscht allerdings erhebliche Verwirrung hinsichtlich des taxonomischen Status einiger Gruppen. Sogar die Definition der Familie selbst ist relativ undeutlich. Um neue Einsichten in die Phylogenie der Bogidielliden s. lat., zu erhalten, fuhrten wir eine kladistische Analyse der Gattungen und Untergattungen unter Verwendung der Computerprogramme PAUP 3.0s und MacClade durch. Die Resultate dieser Analyse dienten als hilfreiche Erganzung bei der umfassenden taxonomischen Revision der Gattungen und Untergattungen. Funf Gattungen wurden aus der Familie entfernt und alle Untergattungen zu Gattungen erhoben. Das Aufspalten von vier Taxa resultierte in 5 neuen Gattungen. Die Familie Bogidiellidae besteht somit aus 33 Gattungen.
Description de quatre nouvelles espèces et de quatre populations de Rotylenchus (Nematoda: Hoplolaimidae). Proposition d'une clé tabulaire
Authors: Germani Gaetano , Massèse Claude Scotto La
Published: July 2002

Summary - Description of four new species and four populations of Rotylenchus (Nematoda: Hoplolaimidae). Proposal a tabular key - Four new species from France are described and figured: Rotylenchus ascalpi sp. n., characterised by an annulated, rounded and set off lip region; R. corsicus sp. n., characterised by a rounded, annulated lip region; R. echelimae sp. n., characterised by a truncated, smooth lip region; R. provincialis sp. n., characterised by a conoïd rounded, annulated lip region and an unannulated tail terminus. The measurements, figures and main morphological differences in relation to the original descriptions of four other populations are given: Rotylenchus capensis , R. eximius, R. magnus jaeni and R. magnus magnus. An emended diagnosis of the genus, a list of valid species and species inquirendae vel dubiae and a tabular key to species are proposed. Quatre nouvelles espèces de Rotylenchus sont décrites et figurées: Rotylenchus ascalpi sp. n., caractérisé par une région céphalique arrondie, comportant de cinq à sept anneaux; R. corsicus sp. n. caractérisé par une région céphalique arrondie, annelée; R. echelimae sp. n., caractérisé par une région céphalique tronconique non annelée; R. provincialis sp. n., caractérisé par une région céphalique annelée, conoïde-arrondie et par l'extrémité caudale lisse. Pour des populations de quatre autres espèces, Rotylenchus capensis, R. eximius, R. magnus jaeni, R. magnus magnus, les mensurations, les figures et les différences morphologiques majeures par rapport aux descriptions originales sont données. Une diagnose amendée du genre, la liste des espèces valides et des species inquirendae vel dubiae ainsi qu'une clé tabulaire pour les espèces sont proposées.
Reduction of Fe(III) in griffithite
Authors: Komadel P. , Madejová J. , Laird D. A. , Xia Y. , Stucki J. W.
Published: July 2002

Griffithite is a trioctahedral smectite with dioctahedral domains, found in the <2 μm fraction of weathered basic rock from Griffith Park, California, USA. Crystalline admixtures (albite, calcite, quartz and maghemite) are concentrated in the 0.2 – 2 μm fraction, while the <0.06 μm fraction contains only trace amounts of other minerals. Griffithite is primarily an Fe–rich saponite with negative charge located in the tetrahedral sheets. The octahedral occupancy is ∼91%, and ∼26% of the octahedra contain trivalent atoms imparting a net positive charge to the octahedral sheet. Medium levels of Fe(III) reduction in griffithite, up to 60% of total Fe, can be achieved by adding solid sodium dithionite to clay dispersions in a citrate–bicarbonate buffer. By contrast >90% reduction of Fe(III) to Fe(II) is achieved in nontronites using the same method. The lower reducibility of Fe(III) in griffithite relative to nontronites may be due to structural differences between griffithite and nontronites, such as a more negative tetrahedral charge and a positive octahedral charge.