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Neighbors
Kinds of Neighbors Selected AbstractsGENETIC DIVERGENCE CORRELATES WITH MORPHOLOGICAL AND ECOLOGICAL SUBDIVISION IN THE DEEP-WATER ELK KELP, PELAGOPHYCUS PORRA (PHAEOPHYCEAE)JOURNAL OF PHYCOLOGY, Issue 5 2000Kathy Ann Miller Pelagophycus porra (Leman) Setchell has a narrow distribution confined to deep water from the Channel Islands off the southern California coast to central Baja California, Mexico. Distinct morphotypes are consistently correlated with distinctive habitats, that is, windward exposures characterized by strong water motion and rocky substrates, and sheltered areas with soft substrates found on the lee sides of the islands. We tested the hypothesis that morphologically and ecologically distinct forms reflect genetically distinct stands. Individuals representing populations from three islands and the mainland were compared using RFLP analyses of the nuclear rDNA internal transcribed spacers (ITS1 and ITS2), chloroplast trnL (UAA) intron sequences, and random amplified polymorphic DNA (RAPDs). No variation was found in a survey of 20 restriction sites of ITS1 (ca. 320 base pair [bp]) and ITS2 (ca. 360 bp) among individuals from six populations. Likewise, comparisons of trnL intron (241 bp) sequences among nine individuals from seven populations were identical with the exception of a CATAGT insert in two adjacent stands. A RAPD analysis of 24 individuals from nine populations (4 windward and 5 leeward) using 16 primers generated 166 bands. Thirty-eight percent of the bands did not vary, 16% were unique to a given individual, and 46% were variable. Neighbor joining analysis produced a well-resolved tree with moderately high bootstrap support in which windward and leeward populations were easily distinguished. The lack of divergence in both the fast evolving nuclear rDNA-ITS and the chloroplast trnL intron does not support the morphotypes as different species. However, the compartmentalized differentiation shown in the RAPD data clearly points to isolation. This, and previous ecological studies that demonstrate habitat specificity suggest that leeward stands probably comprise a species in statu nascendi. [source] Patterns of Vocal Interactions in a Bullfrog (Rana catesbeiana) Chorus: Preferential Responding to Far NeighborsETHOLOGY, Issue 8 2000Su L. Boatright-Horowitz In chorusing species, males seem to be spaced non-randomly, and their vocal interactions may be governed by particular behavioral rules. We monitored patterns of vocal interactions in a natural bullfrog (Rana catesbeiana) chorus to determine the probability with which calls of individual frogs would follow each other's in dyadic sequences. Expected probabilities of responses in a dyad were calculated based upon the joint probabilities of calling (relative calling rates) of the individual frogs; observed probabilities of response reflected the actual number of following responses in each dyad. Results of statistical tests comparing observed and expected probabilities of responding revealed that, when dyads were closely spaced, observed probabilities of a following response were significantly less than the expected probabilities. Conversely, when dyads were composed of more distant males, observed probabilities of responding were significantly greater than expected. Observed probabilities of response were correlated with inter-male distances; males called more frequently than expected following calls of far neighbors, and less frequently than expected following calls of near neighbors. These data suggest that males attend to both nearby and distant callers, and adjust the onset of their own vocalizations appropriately. Males may be actively inhibited by calls of their near neighbors, and their calling may be actively elicited by the calls of their far neighbors. [source] Faith in Our Neighbors: Networks and Social Order in Three Brazilian FavelasLATIN AMERICAN POLITICS AND SOCIETY, Issue 1 2004Enrique Desmond Arias ABSTRACT After nearly 20 years of democratization, residents of Rio's favelas suffer high levels of civil and human rights abuse at the hands of both police and drug traffickers. The government is generally unable to guarantee the political order necessary to protect the rights of residents in these communities. Existing theories of democratization and advocacy networks offer little to explain how the types of endemic violence that affect poor neighborhoods in the developing world can be brought under control. Based on more than two years of participant observation and interviews in Rio de Janeiro, this article examines how democratic order can be extended to favelas. It argues that networks can link favela residents to organizations in civil society, and state actors can play a critical role in reducing violence and establishing democratic order. [source] Estimation of Compartmental Half-lives of Organic Compounds , Structural Similarity versus EPI-SuiteMOLECULAR INFORMATICS, Issue 4 2007Ralph Kühne Abstract A k Nearest Neighbors (KNN) approach is developed to extrapolate from existing semiquantitative compartmental half-lives of organic compounds to respective data for untested substances. It is based on the evaluation of structural similarity through atom-centered fragments (ACFs). For the model development and leave-one-out cross-validation, a set of 293 compounds with reference half-lives for the four compartments air, water, soil, and sediment was taken from literature. Comparative analysis of the model performance with results based on EPI-Suite predictions of degradation rates due to indirect photolysis, biodegradation, and hydrolysis demonstrates the superiority of the new approach to predict compartmental half-lives. The latter are needed as input information for modeling the multimedia fate and life-time of organic compounds. The discussion includes an analysis of the problems associated with converting process-specific loss rates into compartmental half-lives. [source] Neighbors at War: Anthropological Perspectives on Yugoslav Ethnicity, Culture and HistoryAMERICAN ETHNOLOGIST, Issue 3 2001Keith S. Brown Neighbors at War: Anthropological Perspectives on Yugoslav Ethnicity, Culture and History. Joel M. Halpern and David A. Kideckel. eds. University Park: Pennsylvania State University Press, 2000. vii. 477 pp., illustrations, photographs, notes, references, index. [source] Shoot herbivory on the invasive plant, Centaurea maculosa, does not reduce its competitive effects on conspecifics and nativesOIKOS, Issue 3 2006Beth A. Newingham Herbivory can have negative, positive, or no effect on plants. However, insect biological control assumes that herbivory will negatively affect the weed and release natives from competition. Centaurea maculosa, an invader in North America, is tolerant to herbivory, and under some conditions, herbivory may increase its competitive effects on natives. Therefore, we investigated two hypotheses: 1) herbivory stimulates compensatory growth by C. maculosa, which increases its competitive effects, and 2) herbivory stimulates the allelopathic effect of C. maculosa. In the greenhouse, Trichoplusia ni shoot herbivory reduced C. maculosa biomass when shoot damage exceeded 40% of the total original leaf area. Conspecific neighbors had no effect on C. maculosa biomass, and the presence of the natives Festuca idahoensis and F. scabrella had a positive effect on C. maculosa. Neighbors did not alter the effects of shoot herbivory. More importantly, even intense shoot herbivory on C. maculosa did not benefit neighboring plants. In a field experiment, clipping 50% of C. maculosa aboveground biomass in the early summer and again in the late summer reduced final biomass by 40% at the end of the season; however, this clipping did not affect total biomass production or reproductive output. Festuca idahoensis neighbors did not increase the effects of clipping, and aboveground damage to C. maculosa did not release F. idahoensis from competition. In the greenhouse we used activated carbon to adsorb allelochemicals, which reduced the competitive effects of C. maculosa on F. idahoensis but not on F. scabrella or other C. maculosa. However, we found no increase in the allelopathic effects of C. maculosa after shoot herbivory. In summary, our results correspond with others indicating that exceptionally high intensities of herbivory are required to suppress C. maculosa growth and reproduction; however, even intense herbivory on C. maculosa does not insure that native bunchgrasses will benefit. [source] Angels (and Neighbors) Watching Over Us: Child Safety and Family Support in an Age of AlienationAMERICAN JOURNAL OF ORTHOPSYCHIATRY, Issue 1 2010Gary B. Melton First page of article [source] Imaginary Neighbors: Mediating Polish-Jewish Relations after the Holocaust , Edited by Dorota Glowacka and Joanna ZylinskiRELIGIOUS STUDIES REVIEW, Issue 2 2010Scott Ury No abstract is available for this article. [source] FAST AND ROBUST INCREMENTAL ACTION PREDICTION FOR INTERACTIVE AGENTSCOMPUTATIONAL INTELLIGENCE, Issue 1 2005Jonathan Dinerstein The ability for a given agent to adapt on-line to better interact with another agent is a difficult and important problem. This problem becomes even more difficult when the agent to interact with is a human, because humans learn quickly and behave nondeterministically. In this paper, we present a novel method whereby an agent can incrementally learn to predict the actions of another agent (even a human), and thereby can learn to better interact with that agent. We take a case-based approach, where the behavior of the other agent is learned in the form of state,action pairs. We generalize these cases either through continuous k -nearest neighbor, or a modified bounded minimax search. Through our case studies, our technique is empirically shown to require little storage, learn very quickly, and be fast and robust in practice. It can accurately predict actions several steps into the future. Our case studies include interactive virtual environments involving mixtures of synthetic agents and humans, with cooperative and/or competitive relationships. [source] Clustering revealed in high-resolution simulations and visualization of multi-resolution features in fluid,particle modelsCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 2 2003Krzysztof Boryczko Abstract Simulating natural phenomena at greater accuracy results in an explosive growth of data. Large-scale simulations with particles currently involve ensembles consisting of between 106 and 109 particles, which cover 105,106 time steps. Thus, the data files produced in a single run can reach from tens of gigabytes to hundreds of terabytes. This data bank allows one to reconstruct the spatio-temporal evolution of both the particle system as a whole and each particle separately. Realistically, for one to look at a large data set at full resolution at all times is not possible and, in fact, not necessary. We have developed an agglomerative clustering technique, based on the concept of a mutual nearest neighbor (MNN). This procedure can be easily adapted for efficient visualization of extremely large data sets from simulations with particles at various resolution levels. We present the parallel algorithm for MNN clustering and its timings on the IBM SP and SGI/Origin 3800 multiprocessor systems for up to 16 million fluid particles. The high efficiency obtained is mainly due to the similarity in the algorithmic structure of MNN clustering and particle methods. We show various examples drawn from MNN applications in visualization and analysis of the order of a few hundred gigabytes of data from discrete particle simulations, using dissipative particle dynamics and fluid particle models. Because data clustering is the first step in this concept extraction procedure, we may employ this clustering procedure to many other fields such as data mining, earthquake events and stellar populations in nebula clusters. Copyright © 2003 John Wiley & Sons, Ltd. [source] Theology is not Mere Sociology: A Theological Reflection on the Reception of the Christian Religion in Mainland ChinaDIALOG, Issue 3 2004By Pilgrim W.K. Abstract:, Post-Maoist China retains its loyalty to Marxist principles; yet voices are being heard that interpret religion much more positively. Both government spokespersons and Religious Studies scholars measure the value of religion according to its social function. Such a criterion of evaluation fails to take account of what is essential to Christian theology, namely, appeal to divine transcendence. Yet, Christian theology in the tradition of the Lutheran Reformation begins with transcendence and turns toward human responsibility for the world through loving the neighbor. This may mark a common cause between Chinese sociology of religion and Christian commitments to social well-being. [source] Construction of periventricular white matter hyperintensity maps by spatial normalization of the lateral ventriclesHUMAN BRAIN MAPPING, Issue 7 2009Cynthia Jongen Abstract Subcortical and periventricular white matter hyperintensities (WMHs) may have different associations with cognition and pathophysiology. The aim of the present study is to develop an automated method for construction of periventricular WMH maps that enables the analysis of between-group differences in WMH location and characteristics in the periventricular region without the requirement of prior boundary definition. To avoid influence of WMHs on spatial normalization, a reference image of the lateral ventricles was constructed based on images of 24 subjects. Construction was not biased to a single subject. WMHs were segmented by k-nearest neighbor-based classification of magnetic resonance inversion recovery and fluid attenuated inversion recovery images. Cerebrospinal fluid segmentations of individual subjects were nonrigidly mapped to the reference image of the lateral ventricles. The subject's WMHs were transformed to the reference space accordingly. Spatial normalization accuracy was validated using measures of overlap and of displacement relative to the boundary of the lateral ventricles. After spatial normalization, the boundaries of the lateral ventricles closely matched the reference image and in an area of ,1 cm around the lateral ventricles the relative displacement was less than 1 mm. To illustrate the method, it was applied to 61 patients with Type 2 diabetes and 26 control subjects, whereupon periventricular WMH maps were constructed and compared. The proposed method is particularly suited to analyze WMH distribution differences at the level of the lateral ventricles between large groups of patients. Hum Brain Mapp, 2009. © 2008 Wiley-Liss, Inc. [source] Very large-scale neighborhood searchINTERNATIONAL TRANSACTIONS IN OPERATIONAL RESEARCH, Issue 4-5 2000R.K. Ahuja Abstract Neighborhood search algorithms are often the most effective approaches available for solving partitioning problems, a difficult class of combinatorial optimization problems arising in many application domains including vehicle routing, telecommunications network design, parallel machine scheduling, location theory, and clustering. A critical issue in the design of a neighborhood search algorithm is the choice of the neighborhood structure, that is, the manner in which the neighborhood is defined. Currently, the two-exchange neighborhood is the most widely used neighborhood for solving partitioning problems. The paper describes the cyclic exchange neighborhood, which is a generalization of the two-exchange neighborhood in which a neighbor is obtained by performing a cyclic exchange. The cyclic exchange neighborhood has substantially more neighbors compared to the two-exchange neighborhood. This paper outlines a network optimization based methodology to search the neighborhood efficiently and presents a proof of concept by applying it to the capacitated minimum spanning tree problem, an important problem in telecommunications network design. [source] 3 Phylogenetic affinity of the palmelloid green algae, verdigellas and palmophyllum (chlorophyta), based on analyses of nuclear-encoded small subunit rDNA sequencesJOURNAL OF PHYCOLOGY, Issue 2003M. P. Ashworth Palmophyllum, Verdigellas and Palmoclathrus are marine palmelloid green algae with morphologies ranging from closely adherent crusts, peltate discs, to upright branched thalli. Thalli of these taxa are comprised of small spherical cells embedded within a dense mucilaginous matrix. Taxonomic affinities of these palmelloid genera, however, has remained uncertain. Previous studies of Palmophyllum and Verdigellas classified these algae within the Palmellaceae, but the complete absence of data regarding reproduction have blurred ordinal designations. Generally, these algae have been classified as members of the Tetrasporales within the class Chlorophyceae, but the Chlorococcales has also been proposed. Global analyses of eukaryotic nuclear-encoded small subunit rDNA sequences based on parsimony (MP), neighbor joining (NJ) and likelihood (ML) methods confirm the placement of Palmophyllum and Verdigellas as a monophyletic group within the Chlorophyta, but class and ordinal affinities were not clearly resolved. ML suggested that Verdigellas and Palmophyllum are members of a clade with coccoid prasinophyte algae at the base of the Chlorophyta, while NJ and ML suggested that the palmelloid genera formed a basal lineage of the Viridiplantae. A consistent feature of all analyses, however, is that Verdigellas and Palmophyllum did not group with the chlorophycean orders, Tetrasporales or Chlorococcales. Results will be discussed in the context of taxonomy, character evolution, and implications for green plant evolution. (Supported in part by NSF grants DEB-0128952 to MWF, DEB-0129030 to MAB, and DEB-0128977 to FWZ) [source] Semiosis, interaction and ethnicity in urban Java1JOURNAL OF SOCIOLINGUISTICS, Issue 4 2009Zane Goebel This paper teases out the interdiscursive relations between local and perduring signs of personhood and their recontextualization in situated talk. In doing so, I aim to provide further evidence of the utility of incorporating ethnography, linguistic anthropological work on semiotics and work on face-to-face interaction. My empirical focus is on two consecutive men's meetings that occurred in an urban Indonesian milieu. In particular, I draw upon work on semiotic register formation and processes of social identification to flesh out how signs from different temporal-spatial scales figure in the social identification of a non-present neighbor as deviant and Chinese. By taking an interactional view I also attempt to fill a gap in the scholarship on such inter-ethnic relations in Indonesia, which has hitherto primarily been historical in nature. [source] The role of mass spectrometry to study the Oklo,Bangombé natural reactors,MASS SPECTROMETRY REVIEWS, Issue 5 2007J.R. De Laeter Abstract The discovery of the existence of chain reactions at the Oklo natural reactors in Gabon, Central Africa in 1972 was a triumph for the accuracy of mass spectrometric measurements, in that a 0.5% anomaly in the 235U/238U ratio of certain U ore samples indicated a depletion in 235U. Mass spectrometric techniques thereafter played a dominant role in determining the nuclear parameters of the reactor zones themselves, and in deciphering the geochemical characteristics of various elements in the U-rich ore and in the surrounding rock strata. The variations in the isotopic composition of a large number of elements, caused by a combination of nuclear fission, neutron capture and radioactive decay, provide a powerful tool for investigating this unique geological environment. Mass spectrometry can be used to measure the present-day elemental and isotopic abundances of numerous elements, so as to decipher the past history of the reactors and examine the retentivity/mobility of these elements. Many of the fission products have a radioactive decay history that have been used to date the age and duration of the reactor zones, and to provide insight into their nuclear and geochemical behavior as a function of time. The Oklo fission reactors and their near neighbor at Bangombé, some 30 km to the south-east of Oklo, are unique in that not only did they become critical some 2,×,109 years ago, but also the deposits have been preserved over this period of geological time. The long-term geochemical behavior of actinides and fission products have been extensively studied by a variety of mass spectrometric techniques over the past 30 years to provide us with significant information on the mobility/retentivity of this material in a natural geological repository. The Oklo,Bangombé natural reactors are therefore geological analogs that can be evaluated in terms of possible radioactive waste containment sites. As more reactor zones were discovered, it was realized that they could be classified into two groups according to their burial depth in the Oklo mine-site. Reactor Zones 10, 13, and 16 were buried more deeply, and were therefore less weathered than the other zones. The less-weathered zones are of great importance in mobility/retentivity studies and therefore to the question of radioactive waste containment. Isotopic studies of these natural reactors are also of value in physics to examine possible variations in fundamental constants over the past 2 billion years. © 2007 Wiley Periodicals, Inc., Mass Spec Rev 26:683,712, 2007 [source] ECCLESIAL EXISTENCE: PERSON AND COMMUNITY IN THE TRINITARIAN ANTHROPOLOGY OF ADRIENNE VON SPEYRMODERN THEOLOGY, Issue 3 2008MICHELE M. SCHUMACHER Best known for her extraordinary influence upon Hans Urs von Balthasar, Adrienne von Speyr is perhaps overshadowed by the same. Here is an effort to expose her profound mystical insights concerning the specifically Trinitarian dimension of anthropology. Of key significance is the concept of surrender, whereby the human person participates in the fundamental disposition of Christ, whose self-gift is revealed as obedient receptivity vis-à-vis the Father and loving generosity vis-à-vis the world. This in turn is revelatory of the eternal surrender of each divine Person to the Others in a continuous exchange of love. The human person thus participates in divine life by the means that characterize it: love of God and neighbor. [source] Efficient communication in unknown networksNETWORKS: AN INTERNATIONAL JOURNAL, Issue 1 2001Luisa Gargano Abstract We consider the problem of disseminating messages in networks. We are interested in information dissemination algorithms in which machines operate independently without any knowledge of the network topology or size. Three communication tasks of increasing difficulty are studied. In blind broadcasting (BB), the goal is to communicate the source message to all nodes. In acknowledged blind broadcasting (ABB), the goal is to achieve BB and inform the source about it. Finally, in full synchronization (FS), all nodes must simultaneously enter the state terminated after receiving the source message. The algorithms should be efficient both in terms of the time required and the communication overhead they put on the network. We limit the latter by allowing every node to send a message to at most one neighbor in each round. We show that BB is achieved in time at most 2n in any n -node network and show networks in which time 2n , o(n) is needed. For ABB, we show algorithms working in time (2 + ,)n, for any fixed positive constant , and sufficiently large n. Thus, for both BB and ABB, our algorithms are close to optimal. Finally, we show a simple algorithm for FS working in time 3n and a more complicated algorithm which works in time 2.9n. The optimal time of full synchronization remains an open problem. © 2001 John Wiley & Sons, Inc. [source] Exportweltmeister Deutschland , ein Sommermärchen?PERSPEKTIVEN DER WIRTSCHAFTSPOLITIK, Issue 4 2008Bernhard Herz We apply a standard gravity model estimating bilateral export flows of 184 countries and find that Germany's exports are positively affected by time-invariant factors, like its geographical location, but that these factors are not exceptional compared to other OECD countries. Time-varying parameters, like membership in international institutions, also have only limited positive effects on German exports as the positive impact of such institutions is mainly driven by other countries' willingness to participate. Taken together, Germany's current status as the world's leading exporter is not surprising given that it is a middle-sized open high income economy that is neighbor to other open high income countries. [source] Tight binding modelling of electronic band structure in conventional InGaN/GaN and dilute GaAsN/GaAs nitride heterostructuresPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 2 2007H. Hakan Gürel Abstract We utilize a semi-empirical sp3s * tight binding model to investigate the strain and composition effects on electronic structure of conventional InGaN/GaN and dilute GaAsN/GaAs cubic nitride heterostructures. The model includes the second nearest neighbor (2NN) atomic interactions, spin-orbit splitting and nonlinear composition variation of atomic energies and bond lengths of ternaries. Results show that band gaps of conventional InGaN increase with composition for 0 < x < 1. However, the , band gap of dilute GaAsN decreases with composition for x < 0.25 and then starts to increase for 0.26 < x < 1. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Analysis of the local structure of InN with a bandgap energy of 0.8 and 1.9 eV and annealed InN using X-ray absorption fine structure measurementsPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 6 2006Takao Miyajima Abstract We compared the local structure around In atoms in microwave-excited MOCVD- and MBE-grown InN film which indicates an absorption edge at 1.9 and 0.8 eV, respectively. The co-ordination numbers of the 1st-nearest neighbor N atoms and the 2nd-nearest neighbor In atoms for MBE-grown InN were n(N) = 3.9 ± 0.5 and n(In) = 12.4 ± 0.9, which are close to the ideal value of n(N) = 4 and n(In) = 12 for InN without defects, respectively. By thermal annealing, the structure of MBE-grown InN was changed from InN to In2O3, and the absorption edge was changed from 0.8 to 3.5 eV. However, the microwave-excited MOCVD-grown InN had no structure of In2O3, and had the reduced co-ordination numbers of the 2nd-nearest neighbor In atoms of n(In) = 10.6-11.7. From these results, we conclude that the origin of the 1.9-eV absorption edge of InN is the imperfections (defects) of the In lattice sites of InN, rather than the generation of In2O3, which has a bandgap energy of 3.5 eV. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Genetic variation in remnant Festuca hallii populations is weakly differentiated, but geographically associated across the Canadian PrairiePLANT SPECIES BIOLOGY, Issue 3 2009JIE QIU Abstract Genetic diversity is essential for predicting plant evolutionary potential and for formulating conservation strategies. However, little is known about the genetic variation of plains rough fescue [Festuca hallii (Vasey) Piper], a widespread and diagnostic grass in the Fescue Prairie. We used the amplified fragment length polymorphism (AFLP) technique to assess the genetic variation of 30 fragmented populations of F. hallii across the northern Canadian Prairie and its associations with 12 geographical, fragmentation and environmental attributes. Three AFLP primer pairs were used to screen 840 samples, representing approximately 30 samples from each population, and 246 polymorphic bands were scored. The fescue plant was genetically diverse, as revealed by the proportion of polymorphic bands (0.870,0.967), the mean band frequency (0.364,0.457) and the within-population variation (69.4,85.4). The genetic variation was not highly differentiated, with only 6.5% of the total AFLP variation residing among populations. A Mantel test revealed a significant correlation between genetic and geographical distances (r = 0.39; P < 0.004) and a spatial autocorrelation up to 60 km among populations was detected. The AFLP variation displayed a longitudinal decline and was significantly associated with environmental attributes related to moisture, indicating local adaptation. However, the AFLP variation was not significantly associated with the estimated population size and geographical distance to the nearest neighbor, suggesting that fragmentation has not generated considerable genetic impact on the fescue populations. Implications for fescue conservation, restoration and management are discussed. [source] Semantic visual features in content-based video retrievalPROCEEDINGS OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE & TECHNOLOGY (ELECTRONIC), Issue 1 2006Xiangming Mu A new semantic visual features (e.g., car, mountain, and fire) navigation technology is proposed to improve the effectiveness of video retrieval. Traditional temporal neighbor browsing technology allows users to navigate temporal neighbors of a selected sample frame to find additional matches, while semantic visual feature browsing enables users to navigate keyframes that have similar features to the selected sample frame. A pilot evaluation was conducted to compare the effectiveness of three video retrieval designs that support 1) temporal neighbor browsing; 2) semantic visual feature browsing; and 3) fused browsing which is a combination of both temporal neighbor and semantic visual feature browsing. Two types of searching tasks: visual centric and non-visual centric tasks were applied. Initial results indicated that the semantic visual feature browsing system was more efficient for non-visual centric tasks. [source] Approximating average parameters of graphs,,RANDOM STRUCTURES AND ALGORITHMS, Issue 4 2008Oded Goldreich Abstract Inspired by Feige (36th STOC, 2004), we initiate a study of sublinear randomized algorithms for approximating average parameters of a graph. Specifically, we consider the average degree of a graph and the average distance between pairs of vertices in a graph. Since our focus is on sublinear algorithms, these algorithms access the input graph via queries to an adequate oracle. We consider two types of queries. The first type is standard neighborhood queries (i.e., what is the ith neighbor of vertex v?), whereas the second type are queries regarding the quantities that we need to find the average of (i.e., what is the degree of vertex v? and what is the distance between u and v?, respectively). Loosely speaking, our results indicate a difference between the two problems: For approximating the average degree, the standard neighbor queries suffice and in fact are preferable to degree queries. In contrast, for approximating average distances, the standard neighbor queries are of little help whereas distance queries are crucial. © 2008 Wiley Periodicals, Inc. Random Struct. Alg., 2008 [source] Laterality in hand use across four tool-use behaviors among the wild chimpanzees of Bossou, Guinea, West AfricaAMERICAN JOURNAL OF PRIMATOLOGY, Issue 1 2009Tatyana Humle Abstract Population-level right handedness is a human universal, whose evolutionary origins are the source of considerable empirical and theoretical debate. Although our closest neighbor, the chimpanzee, shows some evidence for population-level handedness in captivity, there is little evidence from the wild. Tool-use measures of hand use in chimpanzees have yielded a great deal of variation in directionality and strength in hand preference, which still remains largely unexplored and unexplained. Data on five measures of hand use across four tool-use skills,ant-dipping, algae-scooping, pestle-pounding and nut-cracking,among the wild chimpanzees of Bossou, Guinea, West Africa, are presented here. This study aims to explore age- and sex-class effects, as well as the influence of task motor, cognitive and haptic demands, on the strength and directionality of hand preference within and across all five measures of hand use. Although there was no age- or sex-class effect on the directionality of hand preference, immature ,10 years old tended to be less lateralized than adults, especially adult females. Nut-cracking, the most cognitively complex of the four behaviors and the only one requiring complementary coordination of both hands, yielded the greatest strength in hand use with all adults expressing exclusive use of one hand over the other, without overall significant directional preference. The least lateralized behavior was pestle-pounding, which required bimanual coordination, but also imposed constraints owing to fatigue. It emerged that only the most hazardous tool use, i.e. ant-dipping, and the sole haptic task, i.e. the extraction by hand of crushed oil-palm heart, were laterally biased and both to the right. Shared motor or grip patterns in tool-use skills failed to reveal any specialization in hand use at the individual level. Finally, Bossou chimpanzees demonstrated a tendency for a population-level right-hand use. Am. J. Primatol. 71:40,48, 2009. © 2008 Wiley-Liss, Inc. [source] Molecular Phylogeny of Stentor (Ciliophora: Heterotrichea) Based on Small Subunit Ribosomal RNA SequencesTHE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 1 2007YING-CHUN GONG ABSTRACT. To determine the phylogenetic position of Stentor within the Class Heterotrichea, the complete small subunit rRNA genes of three Stentor species, namely Stentor polymorphus, Stentor coeruleus, and Stentor roeseli, were sequenced and used to construct phylogenetic trees using the maximum parsimony, neighbor joining, and Bayesian analysis. With all phylogenetic methods, the genus Stentor was monophyletic, with S. roeseli branching basally. [source] Reevaluation of the Phylogenetic Relationship between Mobilid and Sessilid Peritrichs (Ciliophora, Oligohymenophorea) Based on Small Subunit rRNA Genes SequencesTHE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 5 2006YING-CHUN GONG ABSTRACT. Based on morphological characters, peritrich ciliates (Class Olygohymenophorea, Subclass Peritrichia) have been subdivided into the Orders Sessilida and Mobilida. Molecular phylogenetic studies on peritrichs have been restricted to members of the Order Sessilida. In order to shed more light into the evolutionary relationships within peritrichs, the complete small subunit rRNA (SSU rRNA) sequences of four mobilid species, Trichodina nobilis, Trichodina heterodentata, Trichodina reticulata, and Trichodinella myakkae were used to construct phylogenetic trees using maximum parsimony, neighbor joining, and Bayesian analyses. Whatever phylogenetic method used, the peritrichs did not constitute a monophyletic group: mobilid and sessilid species did not cluster together. Similarity in morphology but difference in molecular data led us to suggest that the oral structures of peritrichs are the result of evolutionary convergence. In addition, Trichodina reticulata, a Trichodina species with granules in the center of the adhesive disc, branched separately from its congeners, Trichodina nobilis and Trichodina heterodentata, trichodinids without such granules. This indicates that granules in the adhesive disc might be a phylogenetic character of high importance within the Family Trichodinidae. [source] Phylogenetic relationships among the Lorisoidea as indicated by craniodental morphology and mitochondrial sequence dataAMERICAN JOURNAL OF PRIMATOLOGY, Issue 1 2007Judith C. Masters Abstract The phylogeny of the Afro-Asian Lorisoidea is controversial. While postcranial data attest strongly to the monophyly of the Lorisidae, most molecular analyses portray them as paraphyletic and group the Galagidae alternately with the Asian or African lorisids. One of the problems that has bedevilled phylogenetic analysis of the group in the past is the limited number of taxa sampled for both ingroup families. We present the results of a series of phylogenetic analyses based on 635 base pairs (bp) from two mitochondrial genes (12S and 16S rRNA) with and without 36 craniodental characters, for 11 galagid and five lorisid taxa. The outgroup was the gray mouse lemur (Microcebus murinus). Analyses of the molecular data included maximum parsimony (MP), neighbor joining (NJ), maximum likelihood (ML), and Bayesian methods. The model-based analyses and the combined "molecules+morphology" analyses supported monophyly of the Lorisidae and Galagidae. The lorisids form two geographically defined clades. We find no support for the taxonomy of Galagidae as proposed recently by Groves [Primate Taxonomy, Washington, DC: Smithsonian Institution Press. 350 p, 2001]. The taxonomy of Nash et al. [International Journal of Primatology 10:57,80, 1989] is supported by the combined "molecules+morphology" analysis; however, the model-based analyses suggest that Galagoides may be an assemblage of species united by plesiomorphic craniodental characters. Am. J. Primatol. 69:6,15, 2007. © 2006 Wiley-Liss, Inc. [source] Order,disorder twinning model and stacking faults in ,-NTOACTA CRYSTALLOGRAPHICA SECTION B, Issue 5 2006Dieter Schwarzenbach Crystals of the recently published [Bolotina, Kirschbaum & Pinkerton (2005). Acta Cryst. B61, 577,584] triclinic (P) structure of 5-nitro-2,4-dihydro-1,2,4-triazol-3-one (,-NTO) occur as fourfold twins. There are Z, = 4 independent molecules per asymmetric unit. We show that the structure contains layers with 2-periodic layer-group symmetry p21/b 1 (1). This symmetry is lost through the stacking of the layers, which is a possible explanation for Z, = 4. A layer can assume four different but equivalent positions with respect to its nearest neighbor. Twinning arises through stacking faults and is an instructive example of the application of order,disorder theory using local symmetry operations. The near-neighbor relations between molecules remain unchanged through all twin boundaries. The four structures with maximum degree of order, one of which is the observed one, and the family reflections common to all domains are identified. Rods of weak diffuse scattering confirm the stacking model. [source] Self-inclusion structure of 5,11,17,23-tetrakis(azidomethyl)-25,26,27,28-tetrahydroxycalix[4]arene, and 5,11,17,23-tetra- tert -butyl-25,27-bis(chloroacetoxy)-26,28-bis(2-pyridylmethoxy)calix[4]areneACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2009Mei Zhao In the structures of the two title calix[4]arene derivatives, C32H28N12O4, (I), and C60H68Cl2N2O6, (II), compound (I) adopts an open-cone conformation in which there are four intramolecular O,H...O hydrogen bonds, while compound (II) adopts a distorted chalice conformation where the two pendant pyridyl rings, one of which is disordered, are almost mutually perpendicular, with an interplanar angle of 79.2,(2) or 71.4,(2)°. The dihedral angles between the virtual plane defined by the four bridging methylene C atoms and the phenol rings are 120.27,(7), 124.03,(6), 120.14,(8) and 128.25,(7)° for (I), and 95.99,(8), 135.93,(7), 97.21,(8) and 126.10,(8)° for (II). In the supramolecular structure of (I), pairs of molecules associate by self-inclusion, where one azide group of the molecule is inserted into the cavity of the inversion-related molecule, and the association is stabilized by weak intermolecular C,H...N hydrogen bonds and ,(N3),,(aromatic) interactions. The molecular pairs are linked into a two-dimensional network by a combination of weak intermolecular C,H...N contacts. Each network is further connected to its neighbor to produce a three-dimensional framework via intersheet C,H...N hydrogen bonds. In the crystal packing of (II), the molecular components are linked into an infinite chain by intermolecular C,H...O hydrogen bonds. This study demonstrates the ability of calix[4]arene derivatives to form self-inclusion structures. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||