bluuebunny/crossref_metadata_2025 huggingface dataset:
Buckling analysis of buildings braced by frameworks, shear walls and cores
Authors: Zalka K. A.
Published: August 2002

A simple hand method is presented for the three‐dimensional stability analysis of buildings braced by frameworks, coupled shear walls, shear walls and cores. Sway buckling behaviour is characterized by three types of deformation: the full‐height ‘local’ bending of the individual columns, wall sections, shear walls and cores, the full‐height ‘global’ bending of the frameworks and coupled shear walls, which is associated with the axial deformations of the column and wall sections, and the shear deformation of the frameworks and coupled shear walls. Based on the stiffnesses associated with these three types of deformation, a closed formula is derived for the calculation of the sway critical load. An analogy between bending and torsion is used to carry out the pure torsional buckling analysis. The interaction between the bending and shear modes as well as among the basic buckling modes (sway in the principal directions and torsion) are taken into account. A worked example with step‐by‐step instructions shows the easy use of the method. The results of a comprehensive accuracy analysis involving 73 multistorey buildings are also given together with comparisons with other analytical methods. Copyright © 2002 John Wiley & Sons, Ltd.
Realistic face animation for speech
Authors: Kalberer Gregor A. , Van Gool Luc
Published: August 2002

Realistic face animation is especially hard as we are all experts in the perception and interpretation of face dynamics. One approach is to simulate facial anatomy. Alternatively, animation can be based on first observing the visible 3D dynamics, extracting the basic modes, and putting these together according to the required performance. This is the strategy followed by the paper, which focuses on speech. The approach follows a kind of bootstrap procedure. First, 3D shape statistics are learned from a talking face with a relatively small number of markers. A 3D reconstruction is produced at temporal intervals of 1/25 seconds. A topological mask of the lower half of the face is fitted to the motion. Principal component analysis (PCA) of the mask shapes reduces the dimension of the mask shape space. The result is twofold. On the one hand, the face can be animated; in our case it can be made to speak new sentences. On the other hand, face dynamics can be tracked in 3D without markers for performance capture. Copyright © 2002 John Wiley & Sons, Ltd.
Physiological gait controls with a neural pattern generator
Authors: Kuriyama Shigeru , Kurihara Yoshimi , Irino Yusuke , Kaneko Toyohisa
Published: August 2002

This paper proposes a control methodology for human gait with a pattern generator. The pattern generator generates cyclic signals via a couple of mutually inhibited neurons, and drives a proportional derivative controller that supplies joint angles of a virtual human. The state of the pattern generator is entrained by the signal of the controller, and such mutual feedback stabilizes the generation of rhythmic signals for variable conditions. Legs and arms can automatically synchronize their periodical movements without using a central supervisor because the corresponding neural oscillators mutually feed their output signals. Our system generates various gaits in a common mechanism with a small number of parameters, which is well suited for real‐time, interactive and on‐the‐fly controls. Moreover, the movements obtained from motion capture data can be controlled by introducing adjustable non‐linear filters. Copyright © 2002 John Wiley & Sons, Ltd.
Planning characters' behaviour in interactive storytelling
Authors: Cavazza Marc , Charles Fred , Mead Steven J.
Published: August 2002

In this paper, we describe a method for implementing the behaviour of artificial actors in the context of interactive storytelling. We have developed a fully implemented prototype based on the Unreal Tournament™ game engine, and carried experiments with a simple sitcom‐like scenario. We discuss the central role of artificial actors in interactive storytelling and how real‐time generation of their behaviour participates in the creation of a dynamic storyline. We follow previous work describing the behaviour of artificial actors through AI planning formalisms, and adapt it to the context of narrative representation. In this context, the narrative equivalent of a character's behaviour consists of its role. The set of possible roles for a given actor is represented as a hierarchical task network (HTN). The system uses HTN planning to dynamically generate the character roles, by interleaving planning and execution, which supports dynamic interaction between actors, as well as user intervention in the unfolding plot. Finally, we present several examples of short plots and situations generated by the system from the dynamic interaction of artificial actors. Copyright © 2002 John Wiley & Sons, Ltd.
Animating real‐time explosions
Authors: Martins Claude , Buchanan John , Amanatides John
Published: August 2002

Any sufficiently powerful explosion in air creates an expanding blast wave that propagates outwards from the source. The paper explores the physically based simulation of a blast wave impact on surrounding objects. The emphasis is on simplifying the underlying physical and chemical governing equations in order to achieve a visually believable result that performs in real time. A connected voxel model is used to represent objects, so that realistic solid debris is generated instead of flat polygons. The model permits arbitrary voxel shapes, which allow the creation of more complex objects with a lower number of voxels when compared to models using uniform voxel shapes. This model also overcomes certain limitations of the spring–mass particle model when it comes to representing rigid bodies. The paper also explores auxiliary visual effects caused by the blast wave, such as flame, smoke and dust. Each of these cues increases the visual plausibility of the explosion being simulated without being rigorously physically based or computationally intensive. Copyright © 2002 John Wiley & Sons, Ltd.
Accuracy of the fundamental parameter method for x‐ray fluorescence analysis of rocks
Authors: Borkhodoev V. Ya.
Published: August 2002

The accuracy of quantitative X‐ray fluorescence (XRF) analysis of rocks by means of the fundamental parameter (FP) method is predetermined by the completeness of the characteristic X‐radiation model, the degree of uncertainty in the FPs and the correctness of the calculation algorithms. This paper contains the results of a study of these factors for the XRF analysis of rocks that differ greatly in their elemental compositions. In order to improve the model of characteristic X‐radiation, the significance of photoelectrons is thoroughly examined in this paper, and the effects of divergence of the primary radiation beam is assessed. The FP uncertainties are studied in this paper, and equations are derived to calculate the fluorescence yield, probabilities of serial line radiation and absorption jumps. Equations are proposed to calculate the mean electron energy and spectral intensity of X‐ray tube radiation. A numerical integration algorithm is optimized by wavelengths, with allowance for the X‐ray tube bremsstrahlung radiation. A software program is developed to calculate the characteristic radiation intensity and element compositions. Metrologic characteristics of the FP method based XRF analysis allow for its use in rock studies. Copyright © 2002 John Wiley & Sons, Ltd.
Analysis of waste water by x‐ray fluorescence spectrometry
Authors: Eksperiandova L. P. , Blank A. B. , Makarovskaya Y. N.
Published: August 2002

Methods of specimen preparation for the x‐ray fluorescence analysis of water are described. For direct determination of impurities in waste water samples, quasi‐solid specimens based on gelatin (agar) are proposed. Such specimens may also be used after extractive enrichment of impurities and their re‐extraction into the aqueous phase. For organic specimens, those in the form of organogels or thin polymer films can be obtained directly. For group impurity concentration it is proposed to use low‐temperature directed crystallization of water with subsequent obtaining of glassy saccharose‐based specimens from aqueous concentrates. The techniques developed were applied to determine Ag, As, Bi, Cd, Co, Cu, Fe, Ga, Ni, Pb, Se and Zn impurities in waste waters. Copyright © 2002 John Wiley & Sons, Ltd.
Formation features of radiation from x‐ray tubes with grounded cathode
Authors: Pavlinsky G. V. , Portnoy A. Yu.
Published: August 2002

The return of backscattered electrons to an x‐ray tube anode with a grounded cathode leads to appreciable modification of the spectral distribution of the emitted radiation. Results of calculations performed by taking into account the influence of backscattered electrons were compared with published experimental data. The comparison showed reasonably good agreement. The spectral distribution of radiation from an OEG‐75 H x‐ray tube with a grounded cathode, which is used in ARL spectrometers, was calculated. Copyright © 2002 John Wiley & Sons, Ltd.
Soft x‐ray fluorescence measurements in materials science
Authors: Kurmaev E. Z. , Moewes A. , Ederer D. L.
Published: August 2002

A short review of applications of soft x‐ray emission spectroscopy for the study of electronic structure and chemical bonding of advanced materials is presented. It is shown that this technique is very efficient for characterizing different materials such as transition metal compounds, layered superconductors, conducting polymers, metal/polymer interfaces and ion‐implanted insulators. Copyright © 2002 John Wiley & Sons, Ltd.
X‐ray fluorescence analysis in the Russian State Agrochemical Service: an overview
Authors: Pukhovski A. V.
Published: August 2002

The advantages of x‐ray spectrometry in the field of rapid non‐destructive multi‐element analysis of environmental samples have been well known since the 1950s. This was a reason to include this method in the system of analytical control of the Russian State Agrochemical Service (SAS) including regional centers and the Central Research Institute of Agrochemical Service (CINAO), and similar services all over the world. The SAS was organized by the Ministry of Agriculture of the former USSR more than 30 years ago in order to control the status of agricultural soils, quality of forage, plants, fertilizers and fertilizer management. In the previous stage (1980–90), x‐ray spectrometry used all‐vacuum simultaneous spectrometers for the quality control of forages all over the USSR in terms of macro and micro (trace) elemental composition. The program was terminated in the 1990s because of the high cost of operation, slow‐operating apparatus and changes in Russia. However, the new edition of the Agricultural Ministerial Handbook with the regional distribution of mineral nutrients in plants was created owing to the results obtained. Since 1991, more adaptable and inexpensive portable instruments became available and investigations were focused on novel agroecological tasks, e.g. soil pollution with heavy metals. The adaptable and rapid method of soil analysis was evaluated and tested in an interlaboratory study organized by CINAO with the participation of Standard Committee institutes. Relatively good agreement of participant results was demonstrated and information about different kinds of uncertainties in x‐ray fluorescence soil analysis with the use of portable instruments was obtained. This method became used as a standard of the Ministry of Agriculture of the Russian Federation for the rapid analysis of soils to determine the total content of Fe, Zn, Mn, Ni, Sr, Cr and Pb in laboratory and field conditions. Copyright © 2002 John Wiley & Sons, Ltd.
X‐ray fluorescence analysis of rocks, soils and sediments
Authors: Revenko Anatoly G.
Published: August 2002

This paper presents results for the successful determination of trace elements in new reference samples of rocks. The absorption‐enhancement effects were preliminarily investigated theoretically for geological samples of various types. Nineteen trace elements were determined by XRF in the new reference samples applying this technique: SKD‐1 (quartz diorite), SSv‐1 (sviatonossite), BIL‐1 and BIL‐2 (Baikal sediments). In most cases good agreement was achieved between determined and certified values. The method was used for analysing 1500 carbonate sediment samples from the Siberian Platform Foldbelt. It should be noted that low concentrations of some elements are characteristic of the rocks studied and that values are not all available in CRMs. The approach presented in this paper made it possible to solve problems arising during the analysis of carbonate rocks. Copyright © 2002 John Wiley & Sons, Ltd.
Influence of heterogeneous surface morphology on analytical signal formation in total reflection x‐ray fluorescence analysis
Authors: Alov N. V. , Oskolok K. V.
Published: August 2002

The fundamentals of the influence of heterogeneous surface morphology on the analytical signal formation in total reflection x‐ray fluorescence (TXRF) analysis were developed. The dependence of x‐ray fluorescence line intensity on mechanisms of new phase nucleation and growth on a foreign low‐density substrate (reflector) was considered theoretically. The approaches were tested during the study of surfaces of disc glass–ceramic carbon electrodes electrochemically modified by metal deposition and co‐deposition from aqueous solutions. It was shown that TXRF could be effectively applied for the identification of nucleation and growth mechanisms of metal and alloy thin films. Copyright © 2002 John Wiley & Sons, Ltd.
X‐ray spectrometers in Russia: history of their development and present‐day status
Authors: Brytov I. A. , Mezhevich A. N.
Published: August 2002

The background to the development and production of x‐ray instruments in the former USSR and Russia is due to the work of a number of scientists in educational and research institutions. The development of mass‐produced instruments and their practical introduction throughout the country were made possible by the work of the Bourevestnik Research and Production Association. The present overview of x‐ray instruments mostly examines the instruments produced for a broad range of practical applications between 1964 and the present. To some degree, as a consequence of a noticeable lag in this field in the instrument industry, the developments followed the main worldwide trends. However, Soviet scientists also created a number of interesting instruments which were unique for their time and undoubtedly favoured the progress of x‐ray spectral analysis. The overview gives a brief description of the trends in the development and production of x‐ray instruments and their components (crystals, detectors) in the former USSR and Russia. It also presents a brief analysis of today's situation in this field of industry in the world and in Russia. Copyright © 2002 John Wiley & Sons, Ltd.
Application of soft x‐ray emission spectroscopy for the study of solid‐phase reactions in Si‐based interfaces
Authors: Galakhov V. R.
Published: August 2002

The possibilities of soft x‐ray emission spectroscopy with variation of electron excitation energy for the study of solid phase reactions in thin films were analysed. It was shown that Si L2, 3 emission spectra of high‐photon‐energy resolution are sensitive to changes in chemical states of materials, and the variation of the electron excitation energy allows to analyse depth profiles. Si L2, 3 spectra were used for the phase analysis of the Hf/(001)Si, Ir/(111)Si, (Fe + Co)/(001)Si thin films subjected to annealing and SiO2/p‐Si and SiO2/n‐Si films irradiated with high‐energy electrons. The results are compared with data obtained by means of Rutherford backscattering, electron probe microanalysis and optical ellipsometry. Copyright © 2002 John Wiley & Sons, Ltd.
Methodical peculiarities of x‐ray electron probe microanalysis as a promising method to study environmental samples
Authors: Pavlova Ludmila A. , Belozerova Olga Yu. , Paradina Ludmila Ph.
Published: August 2002

The use of x‐ray electron probe microanalysis (EPMA) techniques for environmental objects samples was investigated. Several ZAF and two ϕ(ρz) methods, PAP and the original bi‐exponential model of matrix corrections, were used. The EPMA calculation technique was developed for approximately spherical individual particles of snow‐contained sediments commensurate in size with the area of x‐ray generation. An analytical equation for the size correction of spherical individual particles is proposed. The technique for selecting the optimum EPMA conditions for destruction is reported. Various procedures of the sample preparation were used. Certified basalt glasses containing small amounts of strontium and barium were prepared as reference samples for EPMA. All these procedures provide satisfactory results when applied to the analysis of snow‐contained sediments, coal ash and bones of animals and fish. These samples were investigated with the aim of using them as indicators for evaluating the pollution level of the lower atmosphere and surface and ground water and for revealing pollution mechanisms. The features of EPMA were considered in all studies and the certification characteristics of the techniques were determined. Copyright © 2002 John Wiley & Sons, Ltd.
Investigation of Cr structural positions in spinel with the use of x‐ray emission spectra and cluster calculations
Authors: Vilissov V. A. , Ryzhkov M. V. , Vilissov D. V. , Moloshag V. P.
Published: August 2002

The electronic structure of Cr ions in tetrahedral and octahedral environment was investigated. With the use of X‐ray emission spectra and the results of cluster DV calculations of spinel the dependence between Cr—site coordination and the structure of Cr3d states is evaluated. The comparison of X‐ray emission spectra of chromium states in spinel and other compounds and complexes such as Cr2O72−, CrO42−, Cr(CO)6, Cr2O3was made. Copyright © 2002 John Wiley & Sons, Ltd.
X‐ray diffraction effects in submicron slits and channels
Authors: Ognev L. I.
Published: August 2002

The effects of diffraction on capture of the radiation into narrow channels between two weakly rough surfaces pressed together (‘slitless collimator’) and channeling of x‐radiation in a three‐layered structure with low atomic number thin film inside were investigated. The influence of channel shape distortion and its surface quality on the formation of the outgoing beam was investigated. A plausible explanation is given for the observed effect of abnormality of transmission through Cr/C/Cr thin‐film channels with account of periodic deformation. The calculations of the X‐ray waveguide mode attenuation in thin rough channels were compared with the results of numerical integration of the quasi‐optical equation for electrical field amplitude. Copyright © 2002 John Wiley & Sons, Ltd.
Anomalous width variation for rarefactive ion
acoustic solitary waves in the presence of
warm multi-ions
Authors: GHOSH S. S. , SEKAR IYENGAR A. N.
Published: August 2002

A previous analysis of anomalous width variation for a single-ion
rarefactive solitary wave [S. S. Ghosh and A. N. Sekar Iyengar, Phys. Plasmas,
4, 3204 (1997)] has been extended to a multi-ion species, and shows that the corresponding width–amplitude characteristics depend crucially on the respective ion
concentrations; for example, with increasing light-ion concentration, an ‘increasing-
width’ rarefactive solitary wave transforms to a ‘decreasing-width’ one for a
constant Mach number exhibiting an overall U-shaped variation profile. The influence of the second ion species generally decreases with increasing amplitude,
being maximum for the single to multi-ion transition. However, in the neighbourhood of double-layer-like solutions, the influence again becomes prominent, which
may be associated with the corresponding energy–amplitude relations for both the
ions.
The structure of the double layer
behind the Moon
Authors: BORISOV N. , MALL U.
Published: August 2002

The distribution of plasma and electric fields close to the far side of the
Moon are discussed. The existence of a strong double layer behind the Moon is
predicted and its parameters are investigated. Electric currents associated with
this double layer and finite conductivity inside the Moon are estimated. The fluxes
of suprathermal electrons behind the Moon in different energy ranges are calculated
and compared with the experimental data. It is shown that the theoretical results
are in qualitative agreement with the data obtained by Lunar Prospector and the
Apollo 15 subsatellite.
A note on ion–dust streaming instability in a
collisional dusty plasma
Authors: ROSENBERG M.
Published: August 2002

This note investigates an ion-dust streaming instability with frequency
ω less than the dust collision frequency νd, in an unmagnetized collisional dusty
plasma. Under certain conditions, a resistive instability can be excited by an ion
drift on the order of the ion thermal speed, even when the dust acoustic wave is
heavily damped. The effect of weak collisions on the usual dust acoustic instability
in the regime ω > νd is also considered. Applications to experimental observations
of low-frequency fluctuations in laboratory d.c. glow discharge dusty plasmas are
discussed.
Ontology negotiation between intelligent information agents
Authors: BAILIN SIDNEY C. , TRUSZKOWSKI WALT
Published: August 2002

This paper describes an approach to ontology negotiation between agents supporting intelligent information management. Ontologies are
declarative (data-driven) expressions of an agent's “world”: the objects, operations, facts and rules that constitute the logical space within which an agent performs. Ontology negotiation enables agents to cooperate in performing a task, even if they are based on different ontologies.

Our objective is to increase the opportunities for “strange agents” – that is, agents not necessarily developed within the same framework or with the same contextual operating assumptions – to communicate in solving tasks when they encounter each other on the web. In particular, we have focused on information search
tasks.

We have developed a protocol that allows agents to discover ontology conflicts and then, through incremental interpretation, clarification and explanation,
establish a common basis for communicating with each other. We have implemented this protocol in a set of Java classes that can be added to a variety of agents, irrespective
of their underlying ontological assumptions. We have demonstrated the use of the protocol, through this implementation, in a test-bed that includes two large scientific archives: NASA's Global Change Master Directory and NOAA's Wind and Sea Index.

This paper presents an overview of different methods for resolving ontology mismatches and motivates the Ontology Negotiation Protocol (ONP) as a method that addresses some
problems with other approaches. Much remains to be done. The protocol must be tested in larger and less familiar contexts (for example, numerous archives that have not been preselected) and it must be extended to accommodate additional forms of clarification and ontology evolution.
A UML profile and mapping for the generation of ontology-specific
content languages
Authors: CRANEFIELD STEPHEN , PURVIS MARTIN
Published: August 2002

This paper examines a perceived desire amongst software agent application and platform developers to have the ability to send domain-specific objects within inter-agent messages. If this feature is to be supported without departing from the
notion that agents communicate in terms of knowledge, it is important that the meaning of such objects be well defined. Using an object-oriented metamodelling approach, the relationships between ontologies and agent communication and content languages in FIPA-style agent systems are examined. It is argued that for use with distributed multi-agent systems, ontologies should describe the nature of object identity and
reference for each defined concept, and a UML profile supporting these modelling capabilities is presented. Finally it is shown how, given an ontology in UML, an ontology-specific object-oriented content language can be generated, allowing object structures (viewed in the abstract as UML object diagrams) to be used within message content to represent propositions, definite descriptions or (for classes without identity) value expressions.
Introduction to the special issue on ontologies in agent systems
Authors: CRANEFIELD STEPHEN , WILLMOTT STEVEN , FININ TIM
Published: August 2002

It is now more than ten years since researchers in the US Knowledge Sharing Effort envisaged a future where complex systems could be built by combining knowledge and services from multiple knowledge bases and the first agent communication language, KQML,
was proposed (Neches et al., 1991). This model of communication, based on speech acts, a declarative message content representation language and the use of explicit ontologies defining the domains of discourse (Genesereth & Ketchpel, 1994), has become widely recognised as having great benefits for the integration of disparate and distributed
information sources to form an open, extensible and loosely coupled system. In particular, this idea has become a key tenet in the multi-agent systems research community.
Agents and ontologies for e-business
Authors: LABROU YANNIS
Published: August 2002

Academic work on agents and ontologies is often oblivious to the complexities and realities of enterprise computing. At the same time, the practitioners of enterprise computing, although they are adept at the building of robust, real-life enterprise applications, are unaware of the academic body of work and the opportunities of applying novel approaches of academic origin. Enterprise applications are very complex systems that
are designed to support critical business operations. This article outlines the technical and business foundations of enterprise application software and briefly discusses viable opportunities for agents and ontology research.
A semantic continuum on the semantic web
Authors: USCHOLD MIKE
Published: August 2002

In the coming years, the Web is expected to evolve from a structure containing information resources that have little or no explicit semantics to a structure having a rich semantic
infrastructure. The key defining feature that is intended to distinguish the future Semantic Web from today's Web is that the content of the Web will be usable by machines (i.e. software agents). Meaning needs to be communicated between agents who advertise and/or require the ability to perform tasks on the Web. Agents also need to determine the meaning of passive (i.e. non-agent) information resources on the web to perform these tasks.
IEEE standard upper ontology: a progress report
Authors: PEASE ADAM , NILES IAN
Published: August 2002

The IEEE Standard Upper Ontology (IEEE, 2001) is an effort to create a large, general-purpose, formal
ontology. The ontology will be an open standard that can be reused for both academic and commercial
purposes without fee, and it will be designed to support additional domain-specific ontologies. The
effort is targeted for use in automated inference, semantic interoperability between heterogeneous
information systems and natural language processing applications. The effort was begun in May 2000
with an e-mail discussion list, and since then there have been over 6000 e-mail messages among 170
subscribers. These subscribers include representatives from government, academia and industry in
various countries. The effort was officially approved as an IEEE standards project in December 2000.
Recently a successful workshop was held at IJCAI 2001 to discuss progress and proposals for this
project (IJCAI, 2001).
Temperate freshwater wetlands: types, status, and threats
Authors: Brinson Mark M. , Malvárez Ana Inés
Published: August 2002

This review examines the status of temperate-zone freshwater wetlands and makes projections of how changes over the 2025 time horizon might affect their biodiversity. The six geographic regions addressed are temperate areas of North America, South America, northern Europe, northern Mediterranean, temperate Russia, Mongolia, north-east China, Korea and Japan, and southern Australia and New Zealand. Information from the recent technical literature, general accounts in books, and some first-hand experience provided the basis for describing major wetland types, their status and major threats. Loss of biodiversity is a consequence both of a reduction in area and deterioration in condition. The information base for either change is highly variable geographically. Many countries lack accurate inventories, and for those with inventories, classifications differ, thus making comparisons difficult. Factors responsible for losses and degradation include diversions and damming of river flows, disconnecting floodplain wetlands from flood flows, eutrophication, contamination, grazing, harvests of plants and animals, global warming, invasions of exotics, and the practices of filling, dyking and draining. In humid regions, drainage of depressions and flats has eliminated large areas of wetlands. In arid regions, irrigated agriculture directly competes with wetlands for water. Eutrophication is widespread, which, together with effects of invasive species, reduces biotic complexity. In northern Europe and the northern Mediterranean, losses have been ongoing for hundreds of years, while losses in North America accelerated during the 1950s through to the 1970s. In contrast, areas such as China appear to be on the cusp of expanding drainage projects and building impoundments that will eliminate and degrade freshwater wetlands. Generalizations and trends gleaned from this paper should be considered only as a starting point for developing world-scale data sets. One trend is that the more industrialized countries are likely to conserve their already impacted, remaining wetlands, while nations with less industrialization are now experiencing accelerated losses, and may continue to do so for the next several decades. Another observation is that countries with both protection and restoration programmes do not necessarily enjoy a net increase in area and improvement in condition. Consequently, both reductions in the rates of wetland loss and increases in the rates of restoration are needed in tandem to achieve overall improvements in wetland area and condition.
Status, trends and the future of the marine pelagic ecosystem
Authors: Verity Peter G. , Smetacek Victor , Smayda Theodore J.
Published: August 2002

Globally, humans impact environments and ecosystems faster than they become aware of their effects. The marine pelagic ecosystem includes a tremendously large and diverse environment, which might accordingly be considered to be resilient to externally forced changes, whether from humans or climate. This review considers that general hypothesis by pursuing two objectives. The first is to document the current status of and recent anthropogenic impacts on the marine pelagic ecosystem, with emphasis on the epipelagic zone (0-200 m) where organisms are concentrated and human impacts have been greatest. It shows that humans have proven capable of assuming the role of top carnivore in pelagic ecosystems where living resources are attractive and financially amenable to exploitation, and that overexploitation is the rule under such circumstances. Other anthropogenic activities associated with changes in various marine pelagic ecosystems, such as increased diseases, mortalities, extinctions, habitat invasions, and species replacements, function as sentinels and indicate that portions of the pelagic ecosystem are under considerable stress. It is argued that, without attention, these problems can be expected to worsen up to the year 2025 and beyond. In addition to a comprehensive evaluation of status and trends relating to conservation of the marine pelagic ecosystem, a second major objective is to evaluate whether current paradigms of ecosystem function are sufficient to improve the ability of the scientific community to predict future changes and to recommend relevant management strategies. This review differs from previous ones by proposing that current conceptual models have failed to provide the basis for accurately predicting patterns and features of pelagic communities, notably why specific organisms occur where and when they do. It is argued that predation pressure is shaped by natural selection in the sea as on land, and that it influences organism behaviour, life history strategy and morphology, all of which determine marine pelagic ecosystem structure, and therefore should be used to interpret function. From this perspective, attempting to understand present patterns and predict the future of marine pelagic ecosystems, without understanding the intertwined roles of evolution and predation in forging contemporary pelagic communities, is a hopeless endeavour. It is proposed that both perspectives, resource availability and predation pressure, be incorporated into a revised paradigm of pelagic ecosystem structure and function, a necessity if policies are to predict anthropogenic impacts and environmental conservation is to be effective.
The socioeconomic significance of subsistence non-wood forest products in Leyte, Philippines
Authors: Lacuna-Richman Celeste
Published: August 2002

The literature on non-wood forest products (NWFPs) often emphasizes the commercial potential of certain species. However, the utility of the forest to human communities located in or around it often exceeds the cash income residents get from the sale of commercial NWFPs, as indicated by limiting the harvest of the most marketable NWFPs in a forest-edge Philippine village that was formerly highly dependent on rattan (Calamus sp.) collection and processing as a cottage industry. A village survey showed that there was a correlation between specific socio-economic factors such as age, education, size and income of a household, and household food expenditure, and the knowledge and use of non-commercial NWFPs, which were collected for various purposes. The forest was still important and valued by the community for other uses. These other uses, including the extensive, habitual reliance on subsistence non-wood forest products, are described to illustrate the possibility that these products may be the only source of necessities until the greater economic conditions improve.
The use of breeding dens and kitten development in the Iberian lynx (Lynx pardinus)
Authors: Fernández Néstor , Palomares Francisco , Delibes Miguel
Published: August 2002

The use of breeding dens and the early kitten development was studied in a free‐ranging population of Iberian lynx Lynx pardinus. Radio‐tracking of female lynx allowed intensive monitoring of three litters during 1997, and additional data to be obtained from nine other litters in the previous 4 years. Females gave birth a maximum of one litter per year in spring; nine of the 10 births were recorded between the last 2 weeks of March and the first days of April. Kittens were born semi‐altricial and reared for nearly 20 days in secluded hollow trunks. Afterwards, they were moved between different bushes, which served as auxiliary dens, where they began to develop walking and senses. Kittens first consumed meat at the age of 4 weeks, although they were not fully weaned until they were at least 10 weeks old. At the age of 2 months, kittens began to leave the dens, accompanying their mothers on outings. It is suggested that the pattern of den use was related to the stage of kitten development, to fulfil the kittens' need for both protection and space as they grew. Data on kitten denning and development should be accounted for in in‐situ and ex‐situ conservation programmes for this endangered felid.
The oldest reptile in amber: a 120 million year old lizard from Lebanon
Authors: Arnold E. N. , Azar D. , Ineich I. , Nel A.
Published: August 2002

Animals enclosed in amber often provide a unique insight into their surface structure. Such fossils of reptiles are rare and usually not extremely ancient, the earliest being no more than 40 million years (my). A recently discovered 120 my lizard from the Lower Cretaceous of Lebanon provides direct evidence that several common external features of autarchoglossan lizards had evolved by this time. Ecomorphology indicates that the lizard concerned had considerable climbing ability on open surfaces and perhaps in vegetation, and probably lived in a mesic forested environment, something supported by associated plant and invertebrate remains.
The biology and functional morphology of Humphreyia strangei (Bivalvia: Anomalodesmata: Clavagellidae): an Australian cemented ‘watering pot’ shell
Authors: Morton Brian
Published: August 2002

Amongst the watering pot shells of the Clavagellidae (Anomalodesmata), the least well known is Humphreyia, with a single species H. strangei. Unlike representatives of the other extant clavagellid genera, i.e. Clavagella and Brechites, however, where juveniles are unknown, there is a single juvenile (plus adult specimens) of H. strangei available for study. The Clavagellidae contains the weirdest of all bivalves, encased in a huge (in proportion to the tiny juvenile shell) adventitious tube with an anterior ‘watering pot’. The juvenile H. strangei is dimyarian with a large foot and byssal groove, and a large pedal gape; the entire body is enclosed within a bag‐like periostracum‐covered mantle cavity. Upon permanent residence, however, the anterior watering pot component of the adventitious tube is cemented to the chosen substratum, the adductor muscles are lost and the foot and pedal gape greatly reduced; the fourth pallial aperture closes and the pedal gape and the tubules of the watering pot are similarly occluded. Once cementation is achieved, further growth anteriorly is impossible and the adventitious tube is secreted posteriorly, to house the long siphons, and subsequently can be added to as growth increments. Anatomically, H. strangei has a typical anomalodesmatan arrangement of mantle cavity and digestive organs so that it is, probably, a suspension feeder. Inside the pericardium, however, is a pair of unique proprioreceptors which probably serve to monitor rectal tonus and thus control defecation, co‐ordinated with siphonal retraction and extension. They probably also prevent over‐filling of the capacious rectum. It is believed that cementation and adventitious tube formation occur at the time of sexual maturity and this change in lifestyle between juvenile and adult represents a form of metamorphosis – quite distinct from that which occurs in all bivalves between the pediveliger and juvenile stages – and seems to be unique to Humphreyia and probably Brechites. This family of anomalodesmatan bivalves is thus actually stranger than the already aberrant watering pot would suggest.
Population subdivision among mouflon sheep (Ovis gmelini) ewes and ranging behaviour of rams during the rut
Authors: Martins Ana Gonçalves , Netto Newton Tércio , Aulagnier Stéphane , Borges Ana , Dubois Michel , Vicente Luis , Gerard Jean‐François , Maublanc Marie‐Line
Published: August 2002

Population subdivision among mouflon sheep Ovis gmelini ewes and ranging behaviour of rams were investigated in the Caroux‐Espinouse massif (southern France). Radio‐tracking data from 32 ewes and 41 rams monitored in the course of a 10‐year study were used to identify female units and to document the movement patterns of males during the rutting period. Cluster analyses, based on the distance between arithmetic centres and on the degree of overlap of locations, were computed. Ewes were found to be partitioned in three or four main units to which they were faithful. Movement patterns of rams were much more variable: half were faithful to a rutting range, overlapping one or more unit(s), and the others were not. We suggest that a combination of social and spatial attachment could explain this ranging behaviour. Females build up their spatial habits following their mothers and, when adults, they occupy the area where they have been reared. Their spatial attachment is consistent with their social preferences for other females. Males balance between antagonistic spatial attachment and social preferences for other males, and differ in terms of spatial behaviour. The genetic implications are discussed.
Cautionary comments on the measurement of maximum locomotor capabilities
Authors: Losos Jonathan B. , Creer Douglas A. , Schulte James A.
Published: August 2002

In recent years, laboratory measurements of locomotor performance of small organisms have been used increasingly to study questions in behavioural, physiological, and evolutionary ecology. Although a valuable tool that can provide insight into organismal function, behaviour, and adaptation, this approach is potentially limited by the quality of the data collected. Using the study of maximum sprint speed in lizards as an example, common problems in methodology that may confound interpretation of performance studies are discussed.
Reproductive ecology of a tropical natricine snake, Tropidonophis mairii (Colubridae)
Authors: Brown Gregory P. , Shine Richard
Published: August 2002

Although most snake species are tropical, very little is known about their biology. We monitored reproductive histories of individually marked natricine colubrid snakes (keelbacks, Tropidonophis mairii) for 18‐months in a tropical Australian floodplain. Our data provide the first unambiguous records (for any snake species) of individual females in a natural population producing multiple clutches of eggs during a single breeding season. The snakes bred throughout drier months of the year. The mean size of reproducing females decreased over the season, whereas relative clutch mass increased significantly over the same time period. Larger females produced eggs that were not only larger, but also shorter and wider, than those of smaller females. Despite producing two clutches in short succession, female keelbacks grew over the intervening period. Thus, they switch from ‘capital breeding’ (building up stores of energy during the wet season to use for reproduction in the dry season) to ‘income breeding’ (relying on recently ingested energy to support both growth and reproduction during the dry season). Two females marked at hatching were recaptured as breeding adults <12 months later, confirming that maturation is attained more rapidly in this species than in temperate‐zone natricines.
Identification of twenty‐two bat species (Mammalia: Chiroptera) from Italy by analysis of time‐expanded recordings of echolocation calls
Authors: Russo Danilo , Jones Gareth
Published: August 2002

Spectral and temporal features of echolocation calls emitted by 22 bat species from Italy (three rhinolophids, 18 vespertilionids and the molossid Tadarida teniotis) are described. Time‐expanded recordings of calls from 950 bats of known identity were examined. Rhinolophus ferrumequinum, R. hipposideros, R. euryale and T. teniotis could be identified by measuring the call frequency of highest energy (FMAXE). Quadratic discriminant function analysis with cross‐validation was applied to calls from the remaining 18 species. A function based on start frequency (SF), end frequency (EF), FMAXE and duration (D) provided a correct overall classification of approximately 82%. A classification model at genus level that also comprised middle frequency (MF) and inter‐pulse interval (IPI) reached 94% correct classification. Two separate discriminant functions were devised for species emitting FM (frequency modulated) and FM/QCF calls (i.e. calls consisting of a frequency‐modulated component followed by a terminal part whose frequency is almost constant) respectively. The former function included SF, EF, FMAXE and D and provided an overall classification rate of 71%; the latter comprised EF, MF, D and IPI, and reached 96%. The functions may be applied to bat habitat surveys in southern Italy since they cover most of the species occurring in the area.
The development of blood oxygen stores in bottlenose dolphins (Tursiops truncatus): implications for diving capacity
Authors: Noren Shawn R. , Lacave Geraldine , Wells Randall S. , Williams Terrie M.
Published: August 2002

Enhanced oxygen reserves in the blood facilitate diving in marine mammals. For pinnipeds (seals and sea lions), a developmental period of 4 to 24 months is required for blood oxygen stores to reach adult capacities. We investigated whether a similar developmental period for the blood occurs in cetaceans (dolphins and whales), a group of mammals that are exposed to diving immediately after birth. Blood samples were collected from wild and zoological park bottlenose dolphinsTursiops truncatusaged 0–12 years. Red blood cell number (RBC), haemoglobin content (Hb), haematocrit (Hct), mean corpuscular volume (MCV), mean cell haemoglobin (MCH), and mean corpuscular haemoglobin concentration (MCHC) were determined for each sample. We found that during postnatal development, RBC, Hb and Hct decreased from 0 to 1.5 months and then increased from 1.5 to 6 months, reaching adult levels by 3 years. MCV and MCH both increased from birth. MCHC decreased from 0 to 3.2 months and then increased. Adult levels for MCV were attained as early as 2 months of age while adult levels for MCH and MCHC were attained by 6 months of age. These results indicate that, for bottlenose dolphins, the development of the blood and its capacity to store oxygen is not complete with weaning, which generally occurs at 1.5 years old. The lower oxygen storage capacity of immature dolphins is likely to limit dive capabilities. Calculated aerobic dive limits (cADLs) for 0‐ to 2‐year‐old dolphin calves are 1.9–3.6 min, compared to 4.8–5.4 min for 3‐ to 12‐year‐old dolphins. Increases in cADLs from 0 to 3 years are attributed to increases in both body mass and mass specific oxygen stores while body mass alone explains the increases in cADLs from 3 to 9 years. The limited diving capacity of young dolphins may influence the foraging behaviours of newly weaned juveniles and females accompanied by calves.
Temperature, genetic and hydroperiod effects on metamorphosis of brown frogs Rana arvalis and R. temporaria in the field
Authors: Loman Jon
Published: August 2002

Time for metamorphosis and metamorph size of moor frogs Rana arvalis and common frogs R. temporaria were measured in 22 ponds for 1–8 years. Environmental data in these ponds were also measured. Metamorphosis of the frogs took place from the beginning of June to the beginning of August. When both species were found in one pond, the common frogs metamorphosed up to 20 days earlier than the moor frogs. Most variation in time for metamorphosis, among ponds and years, is explained by temperature effects, but a causal relationship was not established. Within a pond, metamorphosis was later in cold summers than in warm summers. Size at metamorphosis was affected by tadpole density; at high densities metamorphs were smaller. Size at metamorphosis was not related to time for metamorphosis. There was an effect of pond drying; if ponds were about to dry up, metamorphosis was accelerated by about 2.4 days. Tadpoles from ponds with a late metamorphosis in the field had tadpoles that metamorphosed early in a common garden experiment, suggesting counter gradient selection.
Learning rules for information extraction
Authors: TURMO J. , RODRIGUEZ H.
Published: August 2002

The growing availability of textual sources has lead to an increase in the use of automatic
knowledge acquisition approaches from textual data, as in Information Extraction (IE). Most
IE systems use knowledge explicitly represented as sets of IE rules usually manually acquired.
Recently, however, the acquisition of this knowledge has been faced by applying a huge
variety of Machine Learning (ML) techniques. Within this framework, new problems arise in
relation to the way of selecting and annotating positive examples, and sometimes negative
ones, in supervised approaches, or the way of organizing unsupervised or semi-supervised
approaches. This paper presents a new IE-rule learning system that deals with these training
set problems and describes a set of experiments for testing this capability of the new learning
approach.