Distribution by Scientific Domains
Distribution within Life Sciences

Kinds of Novelty

  • evolutionary novelty
  • morphological novelty

  • Terms modified by Novelty

  • novelty preference
  • novelty seeking
  • novelty stress

  • Selected Abstracts

    New species, combinations and records of Hypecoum, Dactylicapnos and Corydalis (Fumariaceae) in China

    NORDIC JOURNAL OF BOTANY, Issue 1-2 2007
    Magnus Lidén
    Five new species of Fumariaceae from the Flora of China area, viz. Hypecoum zhukanum (sect. Leptocarpae), Dactylicapnos gaoligongshanensis (sect. Dactylicapnos), D. leiosperma (sect. Minicalcara), Corydalis laxiflora and C. tianshanica (subgenus Cremnocapnos sect. Strictae), are described. Dactylicapnos burmanica comb. nov., D. grandifoliolata and D. macrocapnos are reported from China for the first time, and the new combinations Dactylicapnos ventii (basion.: Dicentra ventii T. C. Khanh), D. schneideri (basion.: Dicentra schneideri Fedde) and D. burmanica (basion.: Dicentra burmanica K. R. Stern) are validated. Novelties in Corydalis subgenus Corydalis will be published separately. [source]

    Chase, Chance, and Creativity: The Lucky Art of Novelty

    K. A. Jellinger
    No abstract is available for this article. [source]

    Measuring consumer perception of product creativity: Impact on satisfaction and purchasability

    Diana Horn
    In the current value-based economy, product creativity is a potential resource for organizations to compete, thus emphasizing the need for product creativity measurement. Two studies were performed to refine and validate a previously tested model and measurement of consumer perception of product creativity: one with web-based evaluations (N = 208) of chairs and lamps and one with paper-based evaluations (N = 105) of individually selected products. Results of exploratory factor analyses indicated three main product creativity factors: Affect, Importance, and Novelty, which explained 72% of the common variance. Results of stepwise regressions indicated that the Affect factor significantly predicts (65% of the explained variance) willingness to purchase creative consumer products. One major contribution of this research is the finding that affect is as equally (R2 = .28) important as novelty (R2 = .25) in consumer perception of product creativity. Theoretical and practical implications are discussed for the Affect, Importance, and Novelty product creativity factors, and general creativity guidelines are provided for consumer product design. © 2009 Wiley Periodicals, Inc. [source]

    Holiday users of the Internet , ease of use, functionality and novelty

    Chris Ryan
    Abstract This study is based upon a sample of 517 international visitors to New Zealand. It suggests that Internet usage is based upon perceived usefulness and ease of system use. Of additional importance is user confidence about system security. Functional issues of purchasing seem to take priority over information search as users become more familiar with web pages. An additional finding is that entertainment needs are arguably better met by other Internet functions than those provided by destination web pages. Novelty on the Net is perhaps sought from specific sources, and not from the Net generally. Implications are discussed for both measurement and marketing. Copyright © 2008 John Wiley & Sons, Ltd. [source]

    Paradigms and Novelty in Economics: The History of Economic Thought as a Source of Enlightenment

    Wilfred Dolfsma
    Over time, economics has experienced paradigm shifts, and there is every reason to think this will continue. In economics, as in the development of technological knowledge, paradigms do not emerge from nowhere, but build on precursors, possibly from other fields. Our understanding of current economic thinking can be enhanced by paying greater attention to the role of paradigms and by using concepts such as myth, plot structure, and cultural endowment, which are typically given greater attention by literary analysts than by economists, to study paradigms. Here we argue that together these can help us better understand how ideas from other times and fields may be combined with our own to generate better research and publications, and that a greater awareness of the history of economics may well be an excellent vehicle for enhancing that understanding. [source]

    Novelty and Non-Obviousness

    The Relevant Prior Art
    First page of article [source]


    EVOLUTION, Issue 5 2010
    Charles R. Marshall
    The genomes of taxa whose stem lineages branched early in metazoan history, and of allied protistan groups, provide a tantalizing outline of the morphological and genomic changes that accompanied the origin and early diversifications of animals. Genome comparisons show that the early clades increasingly contain genes that mediate development of complex features only seen in later metazoan branches. Peak additions of protein-coding regulatory genes occurred deep in the metazoan tree, evidently within stem groups of metazoans and eumetazoans. However, the bodyplans of these early-branching clades are relatively simple. The existence of major elements of the bilaterian developmental toolkit in these simpler organisms implies that these components evolved for functions other than the production of complex morphology, preadapting the genome for the morphological differentiation that occurred higher in metazoan phylogeny. Stem lineages of the bilaterian phyla apparently required few additional genes beyond their diploblastic ancestors. As disparate bodyplans appeared and diversified during the Cambrian explosion, increasing complexity was accommodated largely through changes in cis -regulatory networks, accompanied by some additional gene novelties. Subsequently, protein-coding genic richness appears to have essentially plateaued. Some genomic evidence suggests that similar stages of genomic evolution may have accompanied the rise of land plants. [source]


    EVOLUTION, Issue 11 2006
    Armin P. Moczek
    Abstract How ecological, developmental and genetic mechanisms interact in the genesis and subsequent diversification of morphological novelties is unknown for the vast majority of traits and organisms. Here we explore the ecological, developmental, and genetic underpinnings of a class of traits that is both novel and highly diverse: beetle horns. Specifically, we focus on the origin and diversification of a particular horn type, those protruding from the pronotum, in the genus Onthophagus, a particularly speciose and morphologically diverse genus of horned beetles. We begin by documenting immature development of nine Onthophagus species and show that all of these species express pronotal horns in a developmentally transient fashion in at least one or both sexes. Similar to species that retain their horns to adulthood, transient horns grow during late larval development and are clearly visible in pupae. However, unlike species that express horns as adults, transient horns are resorbed during pupal development. In a large number of species this mechanisms allows fully horned pupae to molt into entirely hornless adults. Consequently, far more Onthophagus species appear to possess the ability to develop pronotal horns than is indicated by their adult phenotypes. We use our data to expand a recent phylogeny of the genus Onthophagus to explore how the widespread existence of developmentally transient horns alters our understanding of the origin and dynamics of morphological innovation and diversification in this genus. We find that including transient horn development into the phylogeny dramatically reduces the number of independent origins required to explain extant diversity patters and suggest that pronotal horns may have originated only a few times, or possibly only once, during early Onthophagus evolution. We then propose a new and previously undescribed function for pronotal horns during immature development. We provide histological as well as experimental data that illustrate that pronotal horns are crucial for successful ecdysis of the larval head capsule during the larval-to-pupal molt, and that this molting function appears to be unique to the genus Onthophagus and absent in the other scarabaeine genera. We discuss how this additional function may help explain the existence and maintenance of developmentally transient horns, and how at least some horn types of adult beetles may have evolved as exaptations from pupal structures originally evolved to perform an unrelated function. [source]

    Diverse developmental mechanisms contribute to different levels of diversity in horned beetles

    Armin P. Moczek
    Summary An ongoing challenge to evolutionary developmental biology is to understand how developmental evolution on the level of populations and closely related species relates to macroevolutionary transformations and the origin of morphological novelties. Here we explore the developmental basis of beetle horns, a morphological novelty that exhibits remarkable diversity on a variety of levels. In this study, we examined two congeneric Onthophagus species in which males develop into alternative horned and hornless morphs and different sexes express marked sexual dimorphism. In addition, both species differ in the body region (head vs. thorax) that develops the horn. Using a comparative morphological approach we show that prepupal growth of horn primordia during late larval development, as well as reabsorption of horn primordia during the pupal stage, contribute to horn expression in adults. We also show that variable combinations of both mechanisms are employed during development to modify horn expression of different horns in the same individual, the same horn in different sexes, and different horns in different species. We then examine expression patterns of two transcription factors, Distal-less (Dll) and aristaless (al), in the context of prepupal horn growth in alternative male morphs and sexual dimorphisms in the same two species. Expression patterns are qualitatively consistent with the hypothesis that both transcription factors function in the context of horn development similar to their known roles in patterning a wide variety of arthropod appendages. Our results suggest that the origin of morphological novelties, such as beetle horns, rests, at least in part, on the redeployment of already existing developmental mechanisms, such as appendage patterning processes. Our results also suggest, however, that little to no phylogenetic distance is needed for the evolution of very different modifier mechanisms that allow for substantial modulation of trait expression at different time points during development in different species, sexes, or tissue regions of the same individual. We discuss the implications of our results for our understanding of the evolution of horned beetle diversity and the origin and diversification of morphological novelties. [source]

    Re-Forging the ,Age of Iron' Part II: The Tenth Century in a New Age?

    John Howe
    The tenth century, once dismissed as an unpleasant ,Age of Iron', now receives increased attention as an important age of transition. Historians are attempting to understand how it fits into the broader narrative of Western Civilization. Although some scholars have identified it as the last act of the post-Roman world, others see it as a new age. Perhaps the High Middle Ages with its agricultural and demographic revolution, its new villages and parishes, its revived cities, its reformed churches and schools, and its medieval monarchs began in the tenth century? Or were those changes not novelties of the tenth century but rather manifestations of a ,take off' that had already begun back in the Carolingian Empire, and which, despite the problems posed by late Carolingian wars and invasions, was able to continue, spread, and blossom into the growth and prosperity of the High Middle Ages? New scholarly interest in the tenth century has made it much less of a ,dark age', but scholars still are not quite certain how to conceptualize its historical significance. [source]

    Laminar and turbulent flow calculations through a model human upper airway using unstructured meshes

    P. Nithiarasu
    Abstract In this paper, numerical investigation of airflow through a human upper airway is presented using an unstructured-based characteristic-based split (CBS) scheme. The CBS scheme used in the present study employs a fully explicit matrix-free solution procedure along with artificial compressibility. A one equation Spalrat,Allmaras (SA) turbulence model is employed to study low and moderate Reynolds number flows. A detailed discussion of the qualitative and quantitative results is presented. The results show a strong influence of the Reynolds number on the flow pattern and quantities of interest, pressure drop and wall shear stress. It is also apparent that SA model can be employed on unstructured meshes to predict the steady flow with good accuracy. Thus, the novelties of the present paper are: use of the unstructured mesh-based solution algorithm and the successful application of the SA model to a typical human upper airway. Copyright © 2006 John Wiley & Sons, Ltd. [source]

    Finger vein recognition using minutia-based alignment and local binary pattern-based feature extraction

    Eui Chul Lee
    Abstract With recent increases in security requirements, biometrics such as fingerprints, faces, and irises have been widely used in many recognition applications including door access control, personal authentication for computers, Internet banking, automatic teller machines, and border-crossing controls. Finger vein recognition uses the unique patterns of finger veins to identify individuals at a high level of accuracy. This article proposes a new finger vein recognition method using minutia-based alignment and local binary pattern (LBP)-based feature extraction. Our study makes three novelties compared to previous works. First, we use minutia points such as bifurcation and ending points of the finger vein region for image alignment. Second, instead of using the whole finger vein region, we use several extracted minutia points and a simple affine transform for alignment, which can be performed at fast computational speed. Third, after aligning the finger vein image based on minutia points, we extract a unique finger vein code using a LBP, which reduces false rejection error and thus the equal error rate (EER) significantly. Our resulting EER was 0.081% with a total processing time of 118.6 ms. © 2009 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 19, 179,186, 2009 [source]

    Origin of evolutionary novelty: Examples from limbs

    Neil H. Shubin
    Abstract Classic hypotheses of vertebrate morphology are being informed by new data and new methods. Long nascent issues, such as the origin of tetrapod limbs, are being explored by paleontologists, molecular biologists, and functional anatomists. Progress in this arena will ultimately come down to knowing how macroevolutionary differences between taxa emerge from the genetic and phenotypic variation that arises within populations. The assembly of limbs over developmental and evolutionary time offers examples of the major processes at work in the origin of novelties. Recent comparative developmental analyses demonstrate that many of the mechanisms used to pattern limbs are ancient. One of the major consequences of this phenomenon is parallelism in the evolution of anatomical structures. Studies of both the fossil record and intrapopulational variation of extant populations reveal regularities in the origin of variation. These examples reveal processes acting at the level of populations that directly affect the patterns of diversity observed at higher taxonomic levels. J. Morphol. 252:15,28, 2002. © 2002 Wiley-Liss, Inc. [source]

    Functional evolutionary developmental biology (evo-devo) of morphological novelties in plants

    Jisi ZHANG
    Abstract The origin of morphological and ecological novelties is a long-standing problem in evolutionary biology. Understanding these processes requires investigation from both the development and evolution standpoints, which promotes a new research field called "evolutionary developmental biology" (evo-devo). The fundamental mechanism for the origin of a novel structure may involve heterotopy, heterochrony, ectopic expression, or loss of an existing regulatory factor. Accordingly, the morphological and ecological traits controlled by the regulatory genes may be gained, lost, or regained during evolution. Floral morphological novelties, for example, include homeotic alterations (related to organ identity), symmetric diversity, and changes in the size and morphology of the floral organs. These gains and losses can potentially arise through modification of the existing regulatory networks. Here, we review current knowledge concerning the origin of novel floral structures, such as "evolutionary homeotic mutated flowers", floral symmetry in various plant species, and inflated calyx syndrome (ICS) within Solanaceae. Functional evo-devo of the morphological novelties is a central theme of plant evolutionary biology. In addition, the discussion is extended to consider agronomic or domestication-related traits, including the type, size, and morphology of fruits (berries), within Solanaceae. [source]

    Notes on the family Brassicaceae in China

    Dmitry A GERMAN
    Abstract A critical revision of the collections of Brassicaceae in some Chinese (PE, XJA, XJBI, XJFA, XJNM, XJU) and foreign (LE, P) herbaria is made. One genus, Neurotropis (DC.) F. K. Mey., and 11 species, Alyssum szarabiacum Nyár., Barbarea stricta Andrz., Erysimum czernjajevii N. Busch, Erysimum kotuchovii D. German, Erysimum mongolicum D. German, Lepidium karelinianum Al-Shehbaz, Matthiola superba Conti, Neurotropis platycarpa (Fisch. & Mey.) F. K. Mey., Ptilotrichum dahuricum Peschkova, Sisymbrium subspinescens Bunge, and Smelowskia micrantha (Botsch. & Vved.) Al-Shehbaz & S. I. Warwick, are reported from China for the first time. Six species, Aphragmus involucratus (Bunge) O. E. Schulz, Dontostemon perennis C. A. Mey., Goldbachia torulosa DC., Lepidium amplexicaule Willd., Neotorularia brevipes (Kar. & Kir.) Hedge & J. Léonard, and Parrya stenocarpa Kar. & Kir., are confirmed to occurr in China. Five species, Dontostemon integrifolius (L.) C. A. Mey., Draba zangbeiensis L. L. Lou, Lepidium alashanicum H. L. Yang, Sinapis arvensis L., and Strigosella brevipes (Bunge) Botsch., are reported as novelties for some provinces in China, and Strigosella hispida (Litv.) Botsch. occurs in Xinjiang, China. However, the occurrence of one genus, Pseudoarabidopsis Al-Shehbaz, O'Kane & Price, and four species, Draba huetii Boiss., Eutrema halophilum (C. A. Mey.) Al-Shehbaz & S. I. Warwick, Galitzkya spathulata (Steph. ex Willd.) V. Bocz., and Pseudoarabidopsis toxophylla (Bieb.) Al-Shehbaz, O'Kane & Price, could not be confirmed in China. The occurrence of six species, Aphragmus bouffordii Al-Shehbaz, Barbarea orthoceras Ledeb., Lepidium latifolium L., Ptilotrichum canescens (DC.) C. A. Mey., Strigosella hispida (Litv.) Botsch., and Strigosella scorpioides (Bunge) Botsch., is not confirmed in certain provinces of China. All names follow the latest taxonomic treatment for relevant groups; detailed morphological descriptions of the newly recorded taxa are provided; and distinguishing characters from related species already known in China are discussed. Other comments are provided where needed. [source]

    Expression of the Pho regulon negatively regulates biofilm formation by Pseudomonas aureofaciens PA147-2

    Russell D. Monds
    We report the isolation of insertional mutations to the pstC and pstA genes of the phosphate-specific transport (pst) operon that results in loss of biofilm formation by Pseudomonas aureofaciens PA147-2. Consistent with the known roles of the Pst system in Escherichia coli and Pseudomonas aeruginosa, both P. aureofaciens pst mutants were demonstrated to have defects in inorganic phosphate (Pi) transport and repression of Pho regulon expression. Subsequently, biofilm formation by the wild type was shown to require a threshold concentration of extracellular Pi. The two-component regulatory pair PhoR/PhoB is responsible for upregulation of Pho regulon expression in response to Pi -limiting environments. By generating phoR mutants that were unable to express the Pho regulon, we were able to restore biofilm formation by P. aureofaciens in Pi -limiting conditions. This result suggests that gene(s) within the Pho regulon act to regulate biofilm formation negatively in low-Pi environments, and that phoR mutations uncouple PA147-2 from such regulatory constraints. Furthermore, the inability of pst mutants to repress Pho regulon expression accounts for their inability to form biofilms in non-limiting Pi environments. Preliminary evidence suggests that the Pst system is also required for antifungal activity by PA147-2. During phenotypic analysis of pst mutants, we also uncovered novelties in relation to Pi assimilation and Pho regulon control in P. aureofaciens. [source]

    Optimal auditing in the banking industry

    T. Bosch
    Abstract As a result of the new regulatory prescripts for banks, known as the Basel II Capital Accord, there has been a heightened interest in the auditing process. Our paper considers this issue with a particular emphasis on the auditing of reserves, assets and capital in both a random and non-random framework. The analysis relies on the stochastic dynamic modeling of banking items such as loans, reserves, Treasuries, outstanding debts, bank capital and government subsidies. In this regard, one of the main novelties of our contribution is the establishment of optimal bank reserves and a rate of depository consumption that is of importance during an (random) audit of the reserve requirements. Here the specific choice of a power utility function is made in order to obtain an analytic solution in a Lévy process setting. Furthermore, we provide explicit formulas for the shareholder default and regulator closure rules, for the case of a Poisson-distributed random audit. A property of these rules is that they define the standard for minimum capital adequacy in an implicit way. In addition, we solve an optimal auditing time problem for the Basel II capital adequacy requirement by making use of Lévy process-based models. This result provides information about the optimal timing of an internal audit when the ambient value of the capital adequacy ratio is taken into account and the bank is able to choose the time at which the audit takes place. Finally, we discuss some of the economic issues arising from the analysis of the stochastic dynamic models of banking items and the optimization procedure related to the auditing process. Copyright © 2007 John Wiley & Sons, Ltd. [source]

    The European Commission's Guidance on Article 102TFEU: From Inferno to Paradiso?

    THE MODERN LAW REVIEW, Issue 4 2010
    Article first published online: 8 JUL 2010, nar Akman
    The European Commission has for the first time issued a document expressing its official position on the enforcement of Article 102TFEU which prohibits the abuse of a dominant position on the Common Market. The Commission Guidance on enforcement priorities in applying Article 102TFEU to exclusionary abuses (adopted in December 2008) has ended a review of about four years. Given the increased enforcement of Article 102TFEU at the European level and the fact that many national provisions in the EU on unilateral conduct are modelled after Article 102TFEU, how the Commission intends to enforce Article 102TFEU is crucial for the application of competition law and the undertakings subject to it under European and/or national laws. The review period was preceded by severe criticisms of the Commission's approach to Article 102TFEU for protecting competitors instead of competition and for being insufficiently grounded in modern economic thinking. At the heart of the review and the discussions surrounding it lay the question of the objective of Article 102TFEU. Some, including the Directorate General for Competition claimed the objective to be ,consumer welfare', whereas some argued that ,consumer welfare' cannot be adopted as the objective at the expense of the protection of the competitive process. This article critically reviews the Commission Guidance, with an eye to assessing the ultimate objective of and the test of harm under Article 102TFEU. After discussing whether the Guidance indeed sets priorities, it examines the general approach of the Guidance to exclusionary conduct. It points out that despite there being some welcome novelties in the Guidance, there are also suggestions therein whose legitimacy and legality are questionable. Reflecting on the Guidance as a soft-law instrument, the article argues that although regarding the objective of Article 102TFEU, the Commission's apparent tendency towards ,consumer welfare' is not unlawful, the reform of Article 102TFEU to bring it more in line with modern economic and legal thinking seems to be far from complete. [source]

    Turtles as hopeful monsters

    BIOESSAYS, Issue 11 2001
    Olivier Rieppel
    A recently published study on the development of the turtle shell(1) highlights the important role that development plays in the origin of evolutionary novelties(1). The evolution of the highly derived adult anatomy of turtles is a prime example of a macroevolutionary event triggered by changes in early embryonic development. Early ontogenetic deviation may cause patterns of morphological change that are not compatible with scenarios of gradualistic, stepwise transformation. BioEssays 23:987,991, 2001. © 2001 John Wiley & Sons, Inc. [source]

    Conceptual bases for quantifying the role of the environment on gene evolution: the participation of positive selection and neutral evolution

    BIOLOGICAL REVIEWS, Issue 4 2007
    Anthony Levasseur
    Abstract To demonstrate that a given change in the environment has contributed to the emergence of a given genotypic and phenotypic shift during the course of evolution, one should ask to what extent such shifts would have occurred without environmental change. Of course, such tests are rarely practical but phenotypic novelties can still be correlated to genomic shifts in response to environmental changes if enough information is available. We surveyed and re-evaluated the published data in order to estimate the role of environmental changes on the course of species and genomic evolution. Only a few published examples clearly demonstrate a causal link between a given environmental change and the fixation of a genomic variant resulting in functional modification (gain, loss or alteration of function). Many others suggested a link between a given phenotypic shift and a given environmental change but failed to identify the underlying genomic determinant(s) and/or the associated functional consequence(s). The proportion of genotypic and phenotypic variation that is fixed concomitantly with environmental changes is often considered adaptive and hence, the result of positive selection, even though alternative causes, such as genetic drift, are rarely investigated. Therefore, the second aim herein is to review evidence for the mechanisms leading to fixation. [source]

    Amphistemon and Thamnoldenlandia, two new genera of Rubiaceae (Spermacoceae) endemic to Madagascar

    Amphistemon and Thamnoldenlandia are described as two new genera of Rubiaceae endemic to Madagascar. The two novelties belong to the predominantly herbaceous tribe Spermacoceae. Amphistemon is unique within the tribe in having its stamens inserted at two levels in the corolla tube. The genus includes two species: the subshrub A. humbertii and the geoxylic herb A. rakotonasolianus. Thamnoldenlandia includes only one species, T. ambovombensis, which differs from most other Spermacoceae in being a medium-sized shrub with winged seeds. We present a detailed description of Amphistemon and Thamnoldenlandia, including observations of pollen and seeds. A molecular phylogenetic study based on atpB - rbcL, petD, rps16 and trnL - trnF sequences demonstrates that the two new genera belong to the Hedyotis,Oldenlandia complex of tribe Spermacoceae. Amphistemon and Thamnoldenlandia are sister taxa and share a common ancestor with the Madagascan endemic genus Astiella. A second, but not closely related, Madagascan clade includes the endemic genera Lathraeocarpa and Gomphocalyx and the Afro-Madagascan genus Phylohydrax. This indicates that the Madagascan endemic members of Spermacoceae are the result of at least two independent colonization events, most likely by long-distance dispersal from the African mainland. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2010, 163, 447,472. [source]

    The Algebra of Geometric Impossibility: Descartes and Montucla on the Impossibility of the Duplication of the Cube and the Trisection of the Angle

    CENTAURUS, Issue 1 2010
    Jesper Lützen
    Today we credit Pierre Wantzel with the first proof (1837) of the impossibility of doubling a cube and trisecting an arbitrary angle by ruler and compass. However two centuries earlier Descartes had put forward what probably counts as the first proof of these impossibilities. In this paper I analyze this proof, as well as the later related proof given by Montucla (1754) and the brief version of this proof published by Condorcet (1775). I discuss the many novelties of these early arguments and highlight the problematic points addressed by Gauss (1801) and Wantzel. In particular I show that although Descartes developed many of the algebraic techniques used in later proofs he failed to provide an algebraic impossibility proof and resorted to a geometric argument. Montucla and Condorcet turned this proof into an algebraic one. I situate the analysis of the early proof of the impossibility of the two classical problems in the general context of early modern mathematics where mathematics was primarily viewed as a problem solving activity. Within such a paradigm of mathematics impossibility results arguably do not play the role of proper mathematical results, but rather the role of meta-results limiting the problem solving activity. [source]

    Phylogeny and the modalities of acoustic diversification in extant Eneopterinae (Insecta, Orthoptera, Grylloidea, Eneopteridae)

    CLADISTICS, Issue 3 2004
    Tony Robillard
    Calling with a tegminal stridulatory apparatus is widespread in crickets. However, the evolution of cricket stridulums has been poorly studied and then only on the basis of prephylogenetic models, which are unable to account for the huge diversity recently documented for acoustic features in crickets. The present paper focuses on the evolution of acoustic devices in the subfamily Eneopterinae. This is the first attempt to reconstruct the phylogeny of a large and diverse cricket clade in order to analyze the evolution of emitting structures using precise homology statements. In the first step, we reconstruct the phylogeny of this clade using a morphological data set of 193 characters and 45 taxa. The resultant phylogeny supports the monophyly of the subfamily and that of the 13 genera represented by at least two species in our taxonomic sample. Phylogenetic relationships within the subfamily also support the definition of five tribes: Eurepini, Eneopterini, Nisitrini, Xenogryllini and Lebinthini. In the second step, the evolution of acoustic devices is studied by optimization of venation characters defined on precise homology statements. As hypothesized by previous authors, losses of acoustic communication occur independently in the course of eneopterine evolution; however, they happen abruptly with no intermediate state. Our results also document for the first time the modalities of forewing evolution: the diversification of male forewing venation originates from two processes, a continuous and regular modification process, responsible for slight venation change; and an irregular, more intense punctuated process, allowing the emergence of different venations. This diversification process with sudden changes could be related to the occurrence of acoustic novelties in advertisement calls. [source]

    Distributed end-host multicast algorithms for the Knowledge Grid

    Wanqing Tu
    Abstract The Knowledge Grid built on top of the peer-to-peer (P2P) network has been studied to implement scalable, available and sematic-based querying. In order to improve the efficiency and scalability of querying, this paper studies the problem of multicasting queries in the Knowledge Grid. An m -dimensional irregular mesh is a popular overlay topology of P2P networks. We present a set of novel distributed algorithms on top of an m -dimensional irregular mesh overlay for the short delay and low network resource consumption end-host multicast services. Our end-host multicast fully utilizes the advantages of an m -dimensional mesh to construct a two-layer architecture. Compared to previous approaches, the novelty and contribution here are: (1) cluster formation that partitions the group members into clusters in the lower layer where cluster consists of a small number of members; (2) cluster core selection that searches a core with the minimum sum of overlay hops to all other cluster members for each cluster; (3) weighted shortest path tree construction that guarantees the minimum number of shortest paths to be occupied by the multicast traffic; (4) distributed multicast routing that directs the multicast messages to be efficiently distributed along the two-layer multicast architecture in parallel, without a global control; the routing scheme enables the packets to be transmitted to the remote end hosts within short delays through some common shortest paths; and (5) multicast path maintenance that restores the normal communication once the membership alteration appears. Simulation results show that our end-host multicast can distributively achieve a shorter delay and lower network resource consumption multicast services as compared with some well-known end-host multicast systems. Copyright © 2006 John Wiley & Sons, Ltd. [source]

    Two Kinds of Creativity , But Which Ones?

    Geir Kaufmann
    It is argued that Kirton's theory of styles of creativity is conceptually and methodologically unsound. A solution to the conceptual and methodological dilemmas is offered by way of making a clear-cut distinction between novelty on the stimulus and novelty on the response side. This distinction is used as a platform for the development of a new taxonomy of different kinds of creativity and intelligent behaviour. A major feature of this new model is the distinction made between proactive and reactive creativity. The implications of this distinction for opening new avenues for a more differentiated assessment of creativity, as well as for the development of a conceptually firmer and more differentiated platform for developing new practical training programmes in creativity are suggested. [source]

    Designing mouse behavioral tasks relevant to autistic-like behaviors,

    Jacqueline N. Crawley
    Abstract The importance of genetic factors in autism has prompted the development of mutant mouse models to advance our understanding of biological mechanisms underlying autistic behaviors. Mouse models of human neuropsychiatric diseases are designed to optimize (1) face validity, i.e., resemblance to the human symptoms; (2) construct validity, i.e., similarity to the underlying causes of the disease; and (3) predictive validity, i.e., expected responses to treatments that are effective in the human disease. There is a growing need for mouse behavioral tasks with all three types of validity for modeling the symptoms of autism. We are in the process of designing a set of tasks with face validity for the defining features of autism: deficits in appropriate reciprocal social interactions, deficits in verbal social communication, and high levels of ritualistic repetitive behaviors. Social approach is tested in an automated three-chambered apparatus that offers the subject a choice between a familiar environment, a novel environment, and a novel environment containing a stranger mouse. Preference for social novelty is tested in the same apparatus, with a choice between the start chamber, the chamber containing a familiar mouse, and the chamber containing a stranger mouse. Social communication is evaluated by measuring the ultrasonic distress vocalizations emitted by infant mouse pups and the parental response of retrieving the pup to the nest. Resistance to change in ritualistic repetitive behaviors is modeled by forcing a change in habit, including reversal of the spatial location of a reinforcer in a T-maze task and in the Morris water maze. Mouse behavioral tasks that may model additional features of autism are discussed, including tasks relevant to anxiety, seizures, sleep disturbances, and sensory hypersensitivity. Applications of these tests include (1) behavioral phenotyping of transgenic and knockout mice with mutations in genes relevant to autism, (2) characterization of mutant mice derived from random chemical mutagenesis, (3) DNA microarray analyses of genes in inbred strains of mice that differ in social interaction, social communication and resistance to change in habit, and (4) evaluation of proposed therapeutics for the treatment of autism. Published 2004 Wiley-Liss, Inc. MRDD Research Reviews 2004;10:248,258. [source]

    Prenatal predictors of infant temperament

    Elizabeth A. Werner
    Abstract Emerging data suggest that prenatal factors influence children's temperament. In 50 dyads, we examined fetal heart rate (FHR) activity and women's antenatal psychiatric illness as predictors of infant temperament at 4 months (response to novelty and the Infant Behavior Checklist). FHR change during maternal challenge was positively associated with observed infant motor reactivity to novelty (p,=,.02). The odds of being classified as high versus low motor among fetuses who had an increase in FHR during maternal stress was 11 times those who had a decrease in FHR (p,=,.0006). Antenatal psychiatric diagnosis was associated with an almost fourfold greater odds of having a high cry reactivity classification (p,=,.03). There also were modest associations between baseline FHR and maternal reports of infant temperament and between observed temperament and that based on mothers' reports. All of the infant results were found independent of the influence of women's postnatal anxiety. These data indicate that physiological markers of individual differences in infant temperament are identifiable in the fetal period, and possibly shaped by the prenatal environment. © 2007 Wiley Periodicals, Inc. Dev Psychobiol 49: 474-484, 2007. [source]

    Cognitive flexibility in preschoolers: the role of representation activation and maintenance

    Nicolas Chevalier
    Preschoolers' lack of cognitive flexibility has often been attributed to perseverative processing. This study investigates alternative potential sources of difficulty such as deficits in activating previously ignored information and in maintaining currently relevant information. In Experiment 1, a new task tapping attentional switching was designed to isolate the difficulty of overriding an initial representation, that is, perseverative processing (,Perseveration' version), and the difficulty of activating a previously ignored representation, that is, activation deficit (,Activation-deficit' version). Three-year-olds' performance suggested that inflexibility may primarily stem from an activation deficit. Control experiments confirmed that the difficulty of the ,Activation-deficit' version could not be attributed to the effect of attraction to novelty. In Experiment 2, ,distraction' errors, alleged to reflect a failure to maintain a relevant representation, and ,perseverative' errors were distinguished. The results highlighted the important role of representation maintenance in flexibility. The present study indicates that preschoolers' lack of cognitive flexibility is multi-determined and prompts us to reconsider the role of perseveration. [source]

    Neural plasticity and human development: the role of early experience in sculpting memory systems

    Charles A. Nelson
    The concept of sensitive or critical periods in the context of memory development is examined in this paper. I begin by providing examples of the role of experience in influencing sensory, linguistic and emotional functioning. This is followed by a discussion of the role of experience in influencing cognitive functioning, particularly memory. Based on this discussion, speculation is offered that the infant's proclivity for novelty, which makes its appearance shortly after birth, provides critical input into a nervous system that will eventually be set up to learn and remember for the entire lifespan. Because learning and memory are fundamental to the survival of our species, those aspects of the nervous system that permit the encoding and retention of new information are remarkably malleable from the outset, even in the face of some types of neural trauma. This flexibility is retained for many years so long as the learning and memory ,system' is challenged. The implications of this model are discussed in the context of those life events that might undermine the longevity of memory systems. [source]

    crabp and maf highlight the novelty of the amphioxus club-shaped gland

    ACTA ZOOLOGICA, Issue 2 2004
    William R. Jackman
    Abstract The club-shaped gland (csg) is a prominent organ during the development of amphioxus. However, the evolutionary significance of this pharyngeal structure has been a mystery because of the lack of an obvious corollary in vertebrates or other close relatives. To address the homology of the csg by molecular means, we report the cloning and expression patterns of two amphioxus genes expressed during its development, crabp and maf. Amphioxus maf is a bzip transcription factor expressed early in csg formation in the forming of the ventral duct of the gland. crabp encodes a cellular retinoic acid binding protein and is expressed widely in the csg later in its development. We compare these genes to the expression of AmphiKrox, a zinc-finger transcription factor previously reported to be expressed during csg development. Together these genes mark different spatial and temporal aspects of csg formation. However, we find little evidence to suggest homology of the csg with other organs in amphioxus or other chordates. We therefore propose that the csg can be viewed as an evolutionary novelty that probably arose within the amphioxus lineage. [source]