bluuebunny/crossref_metadata_2025 huggingface dataset:
Is Mild Cognitive Impairment Prodromal for Vascular Dementia Like Alzheimer’s Disease?
Authors: Meyer John Stirling , Xu Gelin , Thornby John , Chowdhury Munir H. , Quach Minh
Published: October 2002

Background and Purpose

—

Individuals with mild cognitive impairment (MCI) are at increased risk of Alzheimer’s disease (AD) and probably other forms of dementia. Some subtypes of vascular dementia (VaD) may possess minor neuropathological changes of AD that may contribute to cognitive impairments. It was posited that MCI, identified by criteria described here, might present as a prodrome for VaD and AD.

Methods

—

Serial Mini-Mental State Examination was administered at 3- to 6-month intervals, and neuroimaging was performed annually. Subtle cognitive dysfunctions were weighted and measured according to MCI criteria defined here. Subjects identified with MCI were then followed up for an additional 3.88±3.01 years. Diagnoses of VaD and AD were made according to established criteria.

Results

—

During 3.72±2.94 years of follow-up of the original normative subjects, 73 of 291 (25.1%) developed MCI. Of the 27 subjects who developed VaD, 15 (55.6%) had prodromal MCI. Of these, two thirds were subclassified as having small-vessel dementia. The remaining 12 patients with VaD (44.4%) were diagnosed directly from a cognitively normal status without preceding MCI. These were predominantly multi-infarct or strategic-infarct dementia (66.7%). An additional 35 MCI subjects (47.9%) developed AD. Both VaD and AD diagnosed after MCI prodromes manifested similar spectral domains of cognitive impairments, which included memory, during their MCI stages.

Conclusions

—

In some VaD subtypes, particularly those caused by subcortical microvascular disease, dementia may be preceded by MCI, which has similar domains of cognitive impairment and a similar progressive course that may mimic AD.
Possible Determinants of Early Microembolism After Carotid Endarterectomy
Authors: Stork Jacinda L. , Levi Christopher R. , Chambers Brian R. , Abbott Anne L. , Donnan Geoffrey A.
Published: October 2002

Background and Purpose

—

High numbers of microembolic signals (MES) have been associated with increased risk of postoperative stroke after carotid endarterectomy (CEA). We sought to identify factors predictive of postoperative MES.

Methods

—

Transcranial Doppler monitoring of the ipsilateral middle cerebral artery for MES was performed for 30 minutes during the first postoperative hour in sequential patients undergoing CEA. Stepwise binomial logistic regression analysis was performed to identify preoperative and intraoperative variables that predicted the occurrence of postoperative MES.

Results

—

We studied 141 patients (mean age, 69 years); 102 (72%) were male, and 69 (49%) had at least 1 MES (range, 1 to 118) detected in the first postoperative hour. The risk of postoperative MES was greater in women (
P
=0.027), patients not receiving antiplatelet therapy (
P
=0.033), and patients undergoing left-sided CEA (
P
=0.049). Other variables such as residual stenosis seen on completion angiography and operative technique were not associated with postoperative MES.

Conclusions

—

Postoperative MES were most likely in women, patients not receiving preoperative antiplatelet therapy, and patients who had a left CEA. Microembolism might explain why these same factors are associated with higher rates of perioperative stroke.
Toward Wisdom From Failure
Authors: Gladstone David J. , Black Sandra E. , Hakim Antoine M.
Published: October 2002

Background

—

Neuroprotective drugs for acute stroke have appeared to work in animals, only to fail when tested in humans. With the failure of so many clinical trials, the future of neuroprotective drug development is in jeopardy. Current hypotheses and methodologies must continue to be reevaluated, and new strategies need to be explored.

Summary of Review

—

In part 1, we review key challenges and complexities in translational stroke research by focusing on the “disconnect” in the way that neuroprotective agents have traditionally been assessed in clinical trials compared with animal models. In preclinical studies, determination of neuroprotection has relied heavily on assessment of infarct volume measurements (instead of functional outcomes), short-term (instead of long-term) end points, transient (instead of permanent) ischemia models, short (instead of extended) time windows for drug administration, and protection of cerebral gray matter (instead of both gray and white matter). Clinical trials have often been limited by inappropriately long time windows, insufficient statistical power, insensitive outcome measures, inclusion of protocol violators, failure to target specific stroke subtypes, and failure to target the ischemic penumbra. In part 2, we explore new concepts in ischemic pathophysiology that should encourage us also to think beyond the hyperacute phase of ischemia and consider the design of trials that use multiagent therapy and exploit the capacity of the brain for neuroplasticity and repair.

Conclusions

—

By recognizing the strengths and limitations of animal models of stroke and the shortcomings of previous clinical trials, we hope to move translational research forward for the development of new therapies for the acute and subacute stages after stroke.
Democracy from the Outside-In? International Organizations and Democratization
Authors: Pevehouse Jon C.
Published: October 2002

Scholars and policymakers alike have recently begun to tout the ability of international organizations (IOs) to encourage and secure democracy throughout the world. Despite this stance, little theoretical attention or empirical investigation has attempted to ascertain why or whether this relationship truly exists. One challenge to answering this puzzle is that extant theories of international institutions do not generally delineate clear hypotheses about how IOs influence domestic politics. In this article, I address this paucity of both theory and empirical evidence. I delineate three causal mechanisms that link IOs to domestic actors' calculations about political liberalization and test the argument. I find that membership in regional IOs is correlated with transitions to democracy during the period from 1950 to 1992.
Why is There No NATO in Asia? Collective Identity, Regionalism, and the Origins of Multilateralism
Authors: Hemmer Christopher , Katzenstein Peter J.
Published: October 2002

In this paper, we explain why the U.S. government chose multilateral security arrangements in Europe and bilateral ones in Asia in the 1940s and 1950s. After reviewing the inadequacies of a number of universal and indeterminate explanations, we put forward three explanations—great power status, efficient responses to threats, and regional identity—which rely on the combination of material and social forces for their explanatory power. Starting with common rationalist explanations that focus on material capabilities and institutional efficiency to explain the forms of international cooperation, we add to them the important effect that America's collective identity had on the formulation of its foreign policy goals. U.S. policymakers believed that the United States was a natural part of the North Atlantic community but that Southeast Asia was part of an alien political community. This difference helped drive the U.S. government to adopt divergent policies in two regions that, far from being natural, were constructed politically only in the 1940s. We conclude by pointing to the advantage of eclectic combinations of rationalist and constructivist insights, with an extension to the politics of regional collective identity in the 1990s.
Ethnic Bargaining in the Shadow of Third-Party Intervention
Authors: Cetinyan Rupen
Published: October 2002

Relatively weak ethnic groups mobilize and rebel against their governments just as frequently (or infrequently) as strong ones. However, such seemingly irrational behavior is not inconsistent with a rationalist approach to ethnic separatism. A bargaining model that treatsallthe relevant actors as strategic players suggests that power disparities between an ethnic minority and the state—including those based on a group's access to third-party intervention—should affect how the state treats the group butnotthe likelihood that the group rebels against the state. Greater mistreatment by the state should not be correlated with greater external intervention on a group's behalf. New empirical support for the model is drawn from the Minorities at Risk data set, and the discussion has implications for the field of international relations beyond ethnic conflict to extended deterrence more generally.
Artificial Evolution and Lifelike Creativity
Authors: Etxeberria Arantza
Published: October 2002

This paper discusses the aims and goals of artificial evolution in relation to two of the founding features of A-Life: how to characterize the domain of the possible and the criterion of lifelikeness. It is argued that artificial evolution should aim to understand the evolution of organizations and that this will bring about a better understanding of possible evolutions that could have taken place on Earth.
Incremental Construction and Maintenance of Minimal Finite-State Automata
Authors: Carrasco Rafael C. , Forcada Mikel L.
Published: October 2002

Daciuk et al. [Computational Linguistics 26(1):3–16 (2000)] describe a method for constructing incrementally minimal, deterministic, acyclic finite-state automata (dictionaries) from sets of strings. But acyclic finite-state automata have limitations: For instance, if one wants a linguistic application to accept all possible integer numbers or Internet addresses, the corresponding finite-state automaton has to be cyclic. In this article, we describe a simple and equally efficient method for modifying any minimal finite-state automaton (be it acyclic or not) so that a string is added to or removed from the language it accepts; both operations are very important when dictionary maintenance is performed and solve the dictionary construction problem addressed by Daciuk et al. as a special case. The algorithms proposed here may be straightforwardly derived from the customary textbook constructions for the intersection and the complementation of finite-state automata; the algorithms exploit the special properties of the automata resulting from the intersection operation when one of the finite-state automata accepts a single string.
Hemispheric Encoding Asymmetry is More Apparent Than Real
Authors: Miller Michael B. , Kingstone Alan , Gazzaniga Michael S.
Published: October 2002

Previous neuroimaging studies have claimed a left hemisphere specialization for episodic “encoding” and a right hemisphere specialization for episodic “retrieval.” Yet studies of split-brain patients indicate relatively minor memory impairment after disconnection of the two hemispheres. This suggests that both hemispheres are capable of encoding and retrieval. In the present experiment, we examined the possible limits on encoding capacity of each hemisphere by manipulating the “depth” of processing during the encoding of unfamiliar faces and familiar words in the left and right hemispheres of two split-brain patients. Results showed that only the left hemisphere benefited from deeper (more elaborate) encoding of familiar words, and only the right hemisphere benefited from deeper encoding of unfamiliar faces. Our findings are consistent with the view that hemispheric asymmetries in episodic encoding are related to hemisphere-specific processing of particular stimuli. Convergent with recent neuroimaging studies, these results with split-brain patients also suggest that these hemispheric differences are not due to unique specializations in each half brain for encoding memories, but rather, are due to preferential recruitment of the synaptically closer prefrontal cortex to posterior regions processing material-specific information.
Modulation of Induced Gamma Band Responses in a Perceptual Learning Task in the Human EEG
Authors: Gruber Thomas , Müller Matthias M. , Keil Andreas
Published: October 2002

Fragmented pictures of an object, which appear meaningless when seen for the first time, can easily be identified after the presentation of an unfragmented version of the same picture. The neuronal mechanism for such a rapid perceptual learning phenomenon is largely unknown. Recently, induced gamma band responses (GBRs) have been discussed as a possible physiological correlate of activity in cell assemblies formed by learning. The present study was designed to investigate the modulation of induced GBRs in a perceptual learning task by using a 128-channel EEG montage. In the first sequence of the experiment, fragmented pictures from the Snodgrass and Vandervart inventory were presented. The fragmentation of the pictures was selected that subjects were unable to identify them. In the second experimental sequence the perceptual learning sequence half of the pictures were displayed in their unfragmented version. In the third sequence, all pictures were presented again in the fragmented version. Now, subjects had to rate whether or not they could identify the images. Results showed an increase in spectral gamma power at parietal electrode sites for identified pictures. In addition, neural activity in the gamma band was highly synchronized between posterior electrodes. For pictures not presented in their complete version, we found no such pattern in the third sequence. From our results, we concluded that induced GBRs might represent a signature of synchronized neural activity in a Hebbian cell assembly, activated by the fragmented picture after perceptual learning took place. No difference between identified and unidentified pictures was found in the visual evoked potential in the same time range and in the evoked GBR in the same frequency range as the induced response.
Finding the Self? An Event-Related fMRI Study
Authors: Kelley W. M. , Macrae C. N. , Wyland C. L. , Caglar S. , Inati S. , Heatherton T. F.
Published: October 2002

Researchers have long debated whether knowledge about the self is unique in terms of its functional anatomic representation within the human brain. In the context of memory function, knowledge about the self is typically remembered better than other types of semantic information. But why does this memorial effect emerge? Extending previous research on this topic (see Craik et al., 1999), the present study used event-related functional magnetic resonance imaging to investigate potential neural substrates of self-referential processing. Participants were imaged while making judgments about trait adjectives under three experimental conditions (self-relevance, other-relevance, or case judgment). Relevance judgments, when compared to case judgments, were accompanied by activation of the left inferior frontal cortex and the anterior cingulate. A separate region of the medial prefrontal cortex was selectively engaged during self-referential processing. Collectively, these findings suggest that self-referential processing is functionally dissociable from other forms of semantic processing within the human brain.
Learning Nonregular Languages: A Comparison of Simple Recurrent Networks and LSTM
Authors: Schmidhuber J. , Gers F. , Eck D.
Published: October 2002

In response to Rodriguez's recent article (2001), we compare the performance of simple recurrent nets and long short-term memory recurrent nets on context-free and context-sensitive languages.
Dynamics of the Firing Probability of Noisy Integrate-and-Fire Neurons
Authors: Fourcaud Nicolas , Brunel Nicolas
Published: October 2002

Cortical neurons in vivo undergo a continuous bombardment due to synaptic activity, which acts as a major source of noise. Here, we investigate the effects of the noise filtering by synapses with various levels of realism on integrate-and-fire neuron dynamics. The noise input is modeled by white (for instantaneous synapses) or colored (for synapses with a finite relaxation time) noise. Analytical results for the modulation of firing probability in response to an oscillatory input current are obtained by expanding a Fokker-Planck equation for small parameters of the problem—when both the amplitude of the modulation is small compared to the background firing rate and the synaptic time constant is small compared to the membrane time constant. We report here the detailed calculations showing that if a synaptic decay time constant is included in the synaptic current model, the firing-rate modulation of the neuron due to an oscillatory input remains finite in the high-frequency limit with no phase lag. In addition, we characterize the low-frequency behavior and the behavior of the high-frequency limit for intermediate decay times. We also characterize the effects of introducing a rise time to the synaptic currents and the presence of several synaptic receptors with different kinetics. In both cases, we determine, using numerical simulations, an effective decay time constant that describes the neuronal response completely.
Mixture of Experts Classification Using a Hierarchical Mixture Model
Authors: Titsias Michalis K. , Likas Aristidis
Published: October 2002

A three-level hierarchical mixture model for classification is presented that models the following data generation process: (1) the data are generated by a finite number of sources (clusters), and (2) the generation mechanism of each source assumes the existence of individual internal class-labeled sources (subclusters of the external cluster). The model estimates the posterior probability of class membership similar to a mixture of experts classifier. In order to learn the parameters of the model, we have developed a general training approach based on maximum likelihood that results in two efficient training algorithms. Compared to other classification mixture models, the proposed hierarchical model exhibits several advantages and provides improved classification performance as indicated by the experimental results.
On the Problem in Model Selection of Neural Network Regression in Overrealizable Scenario
Authors: Hagiwara Katsuyuki
Published: October 2002

In considering a statistical model selection of neural networks and radial basis functions under an overrealizable case, the problem of unidentifiability emerges. Because the model selection criterion is an unbiased estimator of the generalization error based on the training error, this article analyzes the expected training error and the expected generalization error of neural networks and radial basis functions in overrealizable cases and clarifies the difference from regular models, for which identifiability holds. As a special case of an overrealizable scenario, we assumed a gaussian noise sequence as training data. In the least-squares estimation under this assumption, we first formulated the problem, in which the calculation of the expected errors of unidentifiable networks is reduced to the calculation of the expectation of the supremum of thex2 process. Under this formulation, we gave an upper bound of the expected training error and a lower bound of the expected generalization error, where the generalization is measured at a set of training inputs. Furthermore, we gave stochastic bounds on the training error and the generalization error. The obtained upper bound of the expected training error is smaller than in regular models, and the lower bound of the expected generalization error is larger than in regular models. The result tells us that the degree of overfitting in neural networks and radial basis functions is higher than in regular models. Correspondingly, it also tells us that the generalization capability is worse than in the case of regular models. The article may be enough to show a difference between neural networks and regular models in the context of the least-squares estimation in a simple situation. This is a first step in constructing a model selection criterion in an overrealizable case. Further important problems in this direction are also included in this article.
Sino the Times: Three Spoken Drama Productions on the Beijing Stage
Authors: Ruru Li
Published: October 2002

Today's modern theatre in Beijing shows new talents and direc—tionsas well as problems that are part of the uncertainties of Chi-nese society—in what may be the most intriguing transitional period in Chinese history.
Augmented Reality As a Tool to Aid the Telerobotic Exploration and Characterization of Remote Environments
Authors: Lawson Shaun W. , Pretlove John R. G. , Wheeler Alison C. , Parker Graham A.
Published: October 2002

The three-dimensional characterization and mapping of remote environments is an important task that generates a good deal of attention both by end users and by researchers across several fields of interest. In the mobile robotics community, a great deal of work has been done in equipping vehicles with sensors that can acquire three-dimensional and even multimodal information about the location and nature of features and objects in remote environments. However, the interpretation of such data using fully autonomous methods, such as computer vision, is usually a highly complex problem that, we believe, is much better suited to a humanoriented solution.

In this paper, we describe our work in the development of augmented reality (AR) techniques for the telerobotic inspection and characterization of remote environments. We describe how we are using stereoscopic camera feedback from a remote vehicle and equipping the human operator with three-dimensional virtual cursors that can be used to interactively measure and model real features and objects in the remote environment. We include a description of the calibration techniques used to correctly align the real and virtual images both statically and under vehicle and camera motion. We also describe how we are using our system to demonstrate the potential of AR for improving the inspection of underground sewer pipes.
Real and Illusory Interactions Enhance Presence in Virtual Environments
Authors: Regenbrecht Holger , Schubert Thomas
Published: October 2002

It has long been argued that the possibility to interact in and with a virtual environment (VE) enhances the sense of presence. On the basis of a three-component model of presence, we specify this hypothesis and argue that the mental representation of possible actions should especially enhance spatial presence, and to a lesser extent the involvement and realness of a VE. We support this hypothesis in three studies. A correlative study showed that self-reported interaction possibilities correlated significantly with spatial presence, but not with the other two factors. A first experimental study showed that possible self-movement significantly increased spatial presence and realness. A second experimental study showed that even the illusion of interaction, with no actual interaction taking place, significantly increased spatial presence.
The Carter Administration and Italy: Keeping the Communists Out of Power Without Interfering
Authors: Njølstad Olav
Published: October 2002

From the late 1940s on, the United States did its best to prevent the Italian Communist Party (PCI)from gaining a role in the Italian government. When Jimmy Carter took office in Washington in 1977, the PCI once again was maneuvering for a share of power in Rome. Some observers in Italy speculated that the new U.S. administration would be less averse than its predecessors had been to the prospect of Communist participation in the Italian government. The Carter administration's initial statements and actions created further ambiguity and may have emboldened some senior PCI officials to step up their efforts to gain at least a share of power. Faced with the prospect that Communists would be invited into a coalition government in Italy, the Carter administration dropped its earlier caution and spoke out unequivocally against a “historic compromise” involving the PCI. Although it is difficult to say whether the more forceful U.S. stance made a decisive difference, the ruling Christian Democrats in Italy were able to keep the Communist Party out of the government.
WON BUDDHISM AS A KOREAN NEW RELIGION
Authors: Pye Michael
Published: October 2002

Won Buddhism was founded in the early 20th century, but although it is one of the more important new religions in modern Korea little research has been undertaken on it to date by non-members. In this introductory study based on field observations and text studies, essential information is presented which will provide a starting point for further investigations. This includes an outline of the historical development, set in motion by the founder Pak Chung-Bin (1891–1943), and of the general features of Won Buddhism as a religion. Particular attention is given to Won Buddhism's role in modernisation processes, to the question of gender balance, and to the sense in which Won Buddhism should be regarded as a "new religion" on the one hand and as a form of "Buddhism" on the other hand. Of methodological interest is a sub-discussion running through the article about the delicate relationship between believers' and observers' accounts of a religion. Four illustrations are included.
THE 'SWORD OF MOUTHS' (JUD. III 16; PS. CXLIX 6; PROV. V 4): A METAPHOR AND ITS ANCIENT NEAR EASTERN CONTEXT
Authors: Berman Joshua
Published: October 2002

The term "double- (or, multi-) edged sword" appears three times in the Hebrew Bible (Jud. iii 16; Prov. v 4; Ps. cxlix 6), and in the Christian Bible (Heb. iv 12; Rev. i 16; ii 12), and once each in the Apocrypha (Sir. xxi 3) and in the Pseudepigrapha (Ahiqar, col. vii 100b). Whether in Hebrew, Aramaic or Greek, the term reads in all of these texts, literally, 'a sword of mouths'. While the word stands as a trope for the potency of speech in only some of its 500 instances in the Hebrew Bible, the 'sword of mouths' does so in seven of its occurrences, across several bodies of literature, while the eighth occurrence offers a slight variation on the theme. Archaeological and philological evidence is brought in support of the notion of the orality of the image of the sword.
Behavioural and cognitive influences of kairomones on an araneophagic jumping spider
Authors: Jackson Robert , Clark Robert , Harland Duane
Published: October 2002

In laboratory experiments, Portia fimbriata, an araneophagic salticid from Queensland, was influenced by olfactory and contact-chemical cues from Jacksonoides queenslandicus, an abundant salticid on which P.fimbriata preys. Four distinct effects were revealed: P.fimbriata (1) moved into and remained in the vicinity of J. queenslandicus, (2) performed undirected leaping, behaviour known to function as speculative hunting by inducing a turning response from not-yet-seen J. queenslandicus, (3) adopted a posture (retracted palps) known to be routine when stalking salticids and (4) showed enhanced attention to optical cues from J. queenslandicus. Laboratory experiments provided no statistical evidence that chemical cues from other prey species affected P.fimbriata, that J. queenslandicus was affected by chemical cues from P. fimbriata or that allopatric Portia were sensitive to chemical cues from J. queenslandicus.
Extrapair paternity in the red bishop (Euplectes orix): is there evidence for the good-genes hypothesis?
Authors: Friedl Thomas W.P. , Klump Georg
Published: October 2002

We investigated the pattern and frequency of extrapair paternity in a colony of the red bishop, a sexually dimorphic and highly polygynous passerine. In particular, we tested whether there was evidence in support of the good-genes hypothesis, stating that females seek extrapair copulations with high-quality males to enhance the genetic quality of their offspring. Paternity analysis of 432 nestlings from 187 broods using non-radioactive multilocus DNA-fingerprinting revealed that 17.6% of nestlings were extrapair young (EPY) and 30.5% of all broods investigated contained at least one EPY. In a pairwise comparison, extrapair fathers were found to have significantly longer tarsi than the within-pair fathers they cuckolded. Furthermore, extrapair fathers were more often territory owners in the previous season,
Is use of a novel food source by young canaries (Serinus canarius) influenced by the sex and familiarity of the adult demonstrator?
Authors: Cadieu  , Cadieu J.-C.
Published: October 2002

The influence of experienced males or females on the use of a novel food (canary seed) by juvenile canaries was studied. The tutors were either the parents, which reared the juvenile or unknown adults. In the Experiment 1, the various tutors and the juvenile could see each other through a transparent wall. We tested (i) in the young: the use of seed, the attraction towards adults and the reduction of fear, if any, brought about by the presence of the tutor, (ii) in the adults: feeding activity. Manipulation of seeds by juveniles was greater in the presence of their father than in the presence of unknown males and a stronger effect of local enhancement was observed. In the presence of familiar or unfamiliar females, manipulation of seeds was always strongly enhanced. Juveniles ingested more seeds in the presence of familiar birds of either sex than in the presence of unfamiliar birds. The study of attraction towards the adults revealed that the young could distinguish familiar from unfamiliar adults. Fear was reduced more strongly in the presence of females and familiar birds. Adult females showed high feeding activity, which was not influenced by the presence of a juvenile whether familiar or not. Among males, the consumption of seed was only high in the presence of a familiar juvenile. Detailed analysis showed that the use of seed by the juveniles was favoured by the reduction of fear brought about by the presence of the father and of females. The feeding activity of adult females significantly facilitated the use of novel food by the young. No significant effect of the presence or the activity of an unfamiliar adult male was found. Experiment 2 showed that a familiar male adult and a juvenile exerted a reciprocal influence on each other. Observation of the father was required for facilitation of seed use by juveniles. The father consumed seed whether it could see the juvenile or not but, seeing the juvenile increased seed intake significantly. In the canary, the male looks after the young, which he feeds after fledging. His behaviour favours the use of new food by the young and hence the survival of his offspring.
The mate-guarding behaviour of male kokanee oncorhynchus nerka
Authors: Morbey Yolanda
Published: October 2002

The patterns of mate-guarding in kokanee (non-anadromous Oncorhynchus nerka) are analysed and discussed in relation to existing theory of precopulatory mate-guarding. Male salmon typically guard females prior to spawning events and aggressively exclude other males from their vicinity. Mate-guarding is thought to increase the likelihood of releasing gametes before other males (during a spawning event) and fertilising the greatest proportion of the clutch. The optimal duration of mate-guarding can be considered in a game context because the mate-guarding behaviour of other males influences the probability of finding an unguarded female if a male leaves a female in search of other opportunities. At the Meadow Creek spawning channel, males guarded females, searched for unguarded females, or joined groups of non-breeding males and females. In accordance with mate-guarding theory, males continued to guard the same females after presumed spawning events (but during her egg deposition period) more often than expected on the basis of random pairing. This prevented some males from ever pairing with females. Gaining familiarity with habitat features may confer a competitive advantage to mate-guarding males and may favour prolonged mate-guarding. Because of the importance of finding nesting females quickly, before other males, unpaired males may wait for pairing opportunities rather than occupy distant satellite positions to breeding pairs.
Chemically mediated effects of injured prey on behavior of both prey and predators
Authors: McCarthy Thomas , Dickey Bradley
Published: October 2002

We examined the behavioral responses of aquatic snails (prey) and two species of crayfish (predators) following exposure to chemical cues from injured snails. Snail survival rates and crayfish capture rates were compared between cued treatments and controls. Snails (Physa gyrina) responded to chemical cues by significantly increasing refuge use (i.e. moving to the waterline, floating or crawl-out behavior). Despite their responses, use of refugia did not influence survival rates. Crayfish species differed in their responses to these same chemicals. Orconectes juvenilis became more active (including increased movements across the substrate and reaching up sides of aquaria). In contrast, the activity levels of Procambarus clarkii did not significantly change. Nevertheless, P. clarkii captured snails in less time than O. juvenilis, regardless of whether injured-snail cue was present, and the presence of these cues did not significantly influence capture times for either crayfish species. This study provides strong evidence that injury-released chemical cues can elicit behavioral responses from both conspecific prey and their predators, but found no benefits of response for either prey or predators. The complex interplay of effects makes it difficult to draw simple, general insights about the benefits of the responses for either participant during a predator-prey interaction.
Population dynamics and damage potential of the burrowing nematode, Radopholus similis, on Anthurium andreanum grown in soil-less medium
Authors: Schrama Peter , Stapel Loes , Amsing Jan
Published: October 2002

In a 14 month pot experiment with Anthurium andreanum cv. Sonate, grown in soil-less medium in glasshouse conditions, burrowing nematode (Radopholus similis) population development and crop damage were investigated. At 9 days after transplanting, plants were inoculated with R. similis at four initial densities (Pi): 0, 100, 1000 and 10 000 per pot. Three to 5 months after inoculation R. similis populations reached maximum densities ranging from 59 000 to 112 000 per pot in roots and from 500 to 1150 per litre of drainage water. The greatest densities occurred at the smallest Pi. Subsequently, nematode populations decreased in the decreasing root mass. Fourteen months after inoculation, root systems of nematode-inoculated treatments were almost completely necrotic and root weights were reduced by 84-91% compared to those of non-inoculated plants. In response to the deteriorating root systems, plant vigour of all nematode-inoculated treatments declined tremendously and flower production was significantly less compared to non-inoculated plants at 6 months after inoculation. During the last 2 months of the experiment, reductions in flowers ranged from 46-70% (number), 30-53% (weight), 19-33% (stem length) and 15-31% (width). The total yield losses of these flower growth parameters, calculated over the 14-month experimental period, ranged from 18-33, 15-35, 9-19 and 6-15%, respectively. Greatest reductions occurred in plants in the treatment with the greatest Pi. In these conditions, the damage threshold was calculated to be equal to or fewer than 100 R. similis per pot.
The African Carnoyidae (Nematoda: Rhigonematida). 4. Abirovulva insolita gen. n., sp. n., parasite of Coromus thomsoni (Polydesmida: Oxydesmidae) from Ivory Coast
Authors: Hunt David
Published: October 2002

Abirovulva gen. n. is proposed for nematode denizens of the gut of various African polydesmid diplopods (Coromus thomsoni , Oxydesmus mimodesmus parabellus , O. sicarius , O. platycercus concolor , Plagiodesmus brunneus , P. variabilis and Prepodesmus ornatus). The new genus is usually accompanied by species of Afrocarnoya (also apparently restricted to polydesmid diplopods) and Rhigonema and is likely to be distributed throughout the Central to West African region. Abirovulva gen. n. is unique amongst African Carnoyidae because of a combination of characters, including the very posteriorly located vulva, the unusual form of the female genital system, presence of a ventral sucker in the male, the shape of the spicules and gubernaculum and the distribution of the male copulatory papillae. Abirovulva insolita gen. n., sp. n. is proposed as the type species and is characterised by: the strongly inflated intestine just posterior to the basal bulb in both sexes, the extremely posterior vulva, both female genital tracts running anteriorly in parallel, presence of a much expanded vagina uterina acting as an egg receptacle, long and robust female tail spike; presence of a ventral sucker in the male, form of the male spicules and gubernaculum, disposition of the 15 copulatory papillae, cuticular callosities on the cloacal lips, well developed, smooth, cephalic cap in the male and the truncate male cephalic extremity. No other genus of African Carnoyidae is known to have such a posterior vulva, ventral sucker in the male or spicules and gubernaculum of such unusual form. Relationships to other genera in the Ransomnematoidea and factors that may influence niche partitioning within the host gut are discussed.
A MONUMENTAL SYNAGOGUE FROM THE FIRST CENTURY: THE CASE OF OSTIA
Authors: Runesson Anders
Published: October 2002

The synagogue at Ostia is one of the most important ancient synagogues. However, no final report from the excavations yet exists, which has left the field open for some debate as to the origin and nature of the building. Apart from discussing matters of terminology and definitions, the present study provides a detailed analysis of the building's architectural development, relating it to other structures at Ostia. It is maintained that the original edifice was public and monumental, containing a triclinium for common meals, and dated to the late Julio-Claudian period. The results of the analysis have implications for how we understand Jewish identity as expressed in architectural form, as well as the relation between Jews and non-Jews in the Diaspora.
"I don't do systems": An interview with Clifford Geertz
Authors: Micheelsen Arun
Published: October 2002

I had the honor of interviewing Clifford Geertz at the Institute for Advanced Studies in Princeton, USA, on October 18, 2000. The interview focused on Geertz's theoretical conceptions, the tradition on which he draws, the critique he has encountered, and on interpretive anthropology's future development. Of particular interest was the clarification of his much-debated method, his definition of symbol and his famous definition of religion as a cultural system. Geertz emphasizes his attempt to exercise an applied pragmatic phenomenological and hermeneutical method without any general theory (or philosophy) of meaning, phenomenology, or culture. He maintains that he only has a conceptual framework inspired by different scholars, which nevertheless has consistent focus and perspective, i.e., meaning and symbol. In relationship to this, Geertz defines his symbol within the Peircean semiotic tradition. Therefore, the term symbol is understood as a sign (an index for example), which becomes a symbol via a cultural interpretation. Furthermore, his definition of religion as a cultural system is, in his view, a nonessentialistic definition and therefore is not—as Talal Asad claims—ethnocentric. Although it is Geertz's opinion that interpretive anthropology has been influenced by postmodernism, he predicts that interpretive anthropology's future development will be in reasonable continuity with its past. In my closing comments I tentatively suggest that Geertz may have a theory of interpretation because of his definition of the symbol, his unavoidable assumptions, and his unique method, which has the capacity of grasping the cultural specific in a general way.
Vermiculite-like minerals in low-grade metasediments from the Coastal Range of central Chile
Authors: Ruiz Cruz M. D. , Puga E. , Aguirre L. , Vergara M. , Morata D.
Published: October 2002

Mixed-layer minerals with optical properties similar to metamorphic vermiculite were identified in rocks belonging to a Palaeozoic and a Triassic formation separated by an angular unconformity and exposed in the Coastal Range of central Chile. Both formations are affected by low-grade metamorphism. The mixed-layer minerals were studied by optical microscopy, X-ray diffraction (XRD), electron microprobe (EMPA), and transmission/ analytical electron microscopy (TEM/AEM). Two types of phyllosilicates were identified: chlorite-vermiculite and mica-chlorite, which are present in the Palaeozoic and Triassic rocks respectively. Chlorite-vermiculite mixed layers form packets with well-defined boundaries and mainly show 1:1 ordered sequences. On the contrary, mica-chlorite mixed layers show, in most cases, random sequences evolving laterally toward chlorite. The AEM data indicate compositions close to that of chlorite in the ternary Si-Al- (Fe+Mg+Mn) diagrams for both types of mixed-layer phyllosilicates. Relative to the coexisting chlorite, they have lower (Fe+Mg) contents, and a higher Si/Al ratio. They are interpreted as products of the transformation of chlorite, developed during prograde metamorphism, and probably represent intermediate, metastable phases, in the chlorite to biotite transformation.
Chlorite composition and geothermometry: a comparative HRTEM/AEM-EMPA-XRD study of Cambrian basic lavas from the Ossa Morena Zone, SW Spain
Authors: López-Munguira A. , Nieto F. , Morata D.
Published: October 2002

Chlorites from Cambrian basaltic vesicular lavas, characterized by relatively highXc (0.81-0.98), gave temperatures of formation of 285 to 350°C (Cathelineau's empirical geothermometer). Both theXcand temperature calculations gave results which were too high for the diagenetic conditions indicated by the interbedded shale mineralogy. The HRTEM and XRD studies indicate the absence of smectite layers in these chlorites; i.e. according to lattice images, the actual value ofXcis 1. The chlorite composition in these basaltic lavas must, therefore, be explained in relation to their whole-rock geochemistry, with which a good correlation has been found. The basaltic lavas are characterized by relatively high FeO/M ratios (3.28±1.66) and must be considered as an Fe-rich system, with similar chemical behaviour to pelitic rocks. In these cases, direct chlorite formation, without a previous smectite precursor, is a normal occurrence and theXccalculation and empirical geothermometric calculations are inadequate.
A high-temperature Fourier transform infrared study of the interlayer and Si–O-stretching region in phengite-2M1
Authors: Mookherjee M. , Redfern S. A. T.
Published: October 2002

A natural phengite-2M1 of composition (K0.95Na0.05)(Al0.76Fe0.14Mg0.10)2 (Si3.25Al0.75)O10(OH1.96F0.04) [a= 5.2173(1) Å, b= 9.0493(2) Å, c= 19.989 (1) Å and β = 95.734(4)°] was studied using in situ high-temperature FTIR. Correlations to structural changes were made using previously-reported neutron diffraction data from the same sample. Correlations have been made between the microscopic atomic displacements (arising from thermal effects) and analogous macroscopic properties, such as bond strain and ditrigonal distortions. Spectra were collected in the far-infrared region to study the behaviour of the interlayer (K+) cation and also in the mid-infrared region to distinguish the Si–O stretching modes. We found anisotropic thermal expansion of the interlayer site. The K O bond length is divided into K Oouter and K Oinner, and the K–Oinner bond length is correlated with the far-infrared spectra. The thermal dependence of the correlation between K–O bond length and corresponding far-infrared stretching frequency is different from the effect of the chemical composition. We also found that the K–O bond strain could be successfully resolved into the sum of inner strain and lattice strain. The Si–O stretching mode, obtained from the mid-infrared measurements, showed only weak changes. However, the neutron refinement data showed different thermal behaviour for distinct crystallographic T-sites.
Hydrolysis of ceramic materials: neoformation or rehydroxylation of clay minerals. Oxygen stable isotope analysis
Authors: Nuñez R. , Capel J . , Reyes E. , Delgado A.
Published: October 2002

Hand-made bricks were manufactured from natural sediments by firing at 700°C and 800°C after which they were hydrothermally altered at 150°C in a high-pressure reactor for 1200 h. Sediments and fired pieces were studied by X-ray diffraction. The <2 μm size-fraction of fired and hydrolysed samples were also studied by X-ray diffraction and oxygen isotope analysis. The oxygen isotope composition of the samples became depleted in 18O by alteration. Our results are consistent with a process of hydration and hydroxylation of the partially destroyed clay minerals in the fired bricks. The work is relevant to understanding the origins and alteration processes in old ceramic materials.
Contrasting clay mineral assemblages in British Lower Palaeozoic slate belts: the influence of geotectonic setting
Authors: Merriman R. J .
Published: October 2002

Regional differences in clay mineralogy are found in British Lower Palaeozoic slate belts formed during Caledonian terrane amalgamation. Extensional basins in Wales, the northern Lake District and the Isle of Man are characterized by a greater diversity of species in clay mineral assemblages. Slates that evolved in these basins contain both the K- and Na-rich products of the 2:1 dioctahedral reaction series. Pyrophyllite, rectorite and corrensite are sporadically distributed but kaolinite is rarely recorded even in lowest-grade mudstones. In contrast, clay assemblages that evolved in the convergent basins of the Scottish Southern Uplands and northern England generally contain fewer mineral species, and Na-micas and pyrophyllite are rare or absent. Na-bearing clays may have been generated from low-temperature mixing of hydrothermal fluids and seawater in the extensional basins. Such fluids appear to have been unavailable in the convergent basins through lack of volcanic activity in the early stages of basin development.
Identification of components in smectite/kaolinite mixtures
Authors: Madejová J . , Kečkéš J . , Pálková H. , Komadel P .
Published: October 2002

Mechanically-prepared binary mixtures of two dioctahedral smectites (of different chemical compositions) with two kaolinites (with different amounts of structural defects) were studied by infrared (IR) spectroscopy to verify the ability of IR spectroscopy to detect small amounts of individual components in the mixtures. The same samples were analysed by X-ray diffraction (XRD) in transmission and reflection geometries to compare the sensitivities of these techniques. Infrared spectroscopy is suitable for detecting small amounts of kaolinite in the smectite-rich samples but is not sensitive to small amounts of smectite in kaolinite-rich samples. The IR spectra of kaolinite/ smectite mixtures have a ‘strongly kaolinitic character’ even with only 30% kaolinite. The most characteristic band of kaolinite, near 3695 cm–1, gradually decreased in intensity with decreasing kaolinite content though the presence of this absorption allowed 0.5 mass % of both kaolinites to be detected in their mixtures with smectites. On the other hand, XRD powder techniques are much more adept at detecting low smectite contents in kaolinite-rich samples.