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Kinds of Show Terms modified by Show Selected AbstractsThe Historical Geographies of Showing Livestock: a Case Study of the Perth Royal Show, Western AustraliaGEOGRAPHICAL RESEARCH, Issue 3 2010RICHARD YARWOOD Abstract This paper examines changes in the entries of livestock to competitions at the Perth Royal Show in the course of the twentieth century. It identifies trends in the showing of animals at the Show and explains these with reference to the wider geographies of state and national agricultural change in Western Australia (WA). In doing so, it provides a longitudinal perspective on the socioeconomic contexts of farming in WA and identifies some of the key cultural and economic drivers that have influenced livestock farming in that locality. In turn, these findings contribute to wider understandings of the global countryside and of the imagined ruralities that exist within and beyond the spaces of showgrounds. [source] Defensive Copers Show a Deficit in Passive Avoidance Learning on Newman's Go/No-Go Task: Implications for Self-Deception and SocializationJOURNAL OF PERSONALITY, Issue 5 2004Matthew S. Shane High-anxious individuals, low-anxious individuals, and defensive copers completed a computerized go/no-go task, in which they learned when to press or not to press a button, in response to contingent positive and negative feedback. The duration that feedback remained onscreen was self-regulated. Defensive copers showed preferential reflection away from negative feedback, committed more passive-avoidance errors, and were characterized by impaired learning, overall. Further, the ratio of reflection on negative feedback to reflection on positive feedback directly mediated both passive-avoidance errors and overall learning. Defensive coping strategies, therefore, appear to interfere with passive avoidance learning, thereby fostering perseverative, dysfunctional action patterns by reducing knowledge gained from previous mistakes. Implications for the learning of effective socialization strategies, and for psychopathy,which is commonly characterized by similar passive-avoidance deficits,are subsequently considered. [source] The Land, the Bible, and History: Toward the Land that I Will Show You , By Alain A.A. Marchadour and David S.J. NeuhausMODERN THEOLOGY, Issue 4 2007Alain Epp Weaver First page of article [source] Vitamin D and Health: What Does the Latest Research Show?NURSING FOR WOMENS HEALTH, Issue 1 2008Claudia R Ravin MSN, RN-BC First page of article [source] How to Lose Weight and Keep it Off: What Does the Evidence Show?NURSING FOR WOMENS HEALTH, Issue 2 2007Mary Ann Faucher CNM First page of article [source] What Does the Generality Problem Show?PACIFIC PHILOSOPHICAL QUARTERLY, Issue 2 2001Audre Jean Brokes First page of article [source] A Show about Nothing: Seinfeld and the Modern Comedy of MannersTHE JOURNAL OF POPULAR CULTURE, Issue 1 2000David P. Pierson First page of article [source] Mechanistic Surprises in the Gold(I)-Catalyzed Intramolecular Hydroarylation of Allenes,ANGEWANDTE CHEMIE, Issue 31 2009Dieter Weber Zwei machen die Show: Mechanistische Studien über die Cyclisierung von allenischen Arenen zeigen, dass die Ruheform des Katalysators ein zweikerniges verbrücktes Vinylsystem ist. Dieses wurde isoliert, und seine Reaktivität wurde untersucht. [source] Cold War Illuminations of the Classical Past: ,The Sound and Light Show, on the Athenian AcropolisART HISTORY, Issue 4 2001Elisabeth MarloweArticle first published online: 23 DEC 200 Drawing upon the text of ,The Sound and Light Show' and French and Greek newspaper coverage of the show's premier in 1959, this article uses the metaphor of the museum to consider the ways in which the show limits and controls the history that the Acropolis monuments are allowed to represent. I argue that the show's premise of a causal link between the defeat of tyrannical Eastern enemies and the flourishing of democracy and the arts is a product of the Cold War. This ideological backdrop can be traced through the dramatic events surrounding the show's star-studded, international premier and the richly nuanced political controversies that it reflected and in turn provoked. [source] On the Hot Seat: Mike Wallace interviews Marcel DuchampART HISTORY, Issue 1 2000Naomi Sawelson-Gorse Marcel Duchamp (1887,1968) attained fame early in his career due to the succès-de-scandale surrounding his painting, Nude Descending the Staircase, No. 2 (1912), when it was exhibited at the 1913 New York Armory Show. Seemingly derisive of all Western aesthetic canons, the work came to embody the general public's outrage and confusion about modern art, which seemed to them merely a shameless hoax, while it achieved an iconic stature for modern art's defenders and supporters. Similar polar sentiments persisted in mid-century. Concurrent with Duchamp's re-emergence as an art celebrity, the then new medium of television broadcast art-based programmes directly targeted at a burgeoning American middle class (mostly white, Eastern, suburbanites), who were themselves fuelling an ever-expanding and high-priced art market. With inflated prices, the nagging question was whether consumers were being bilked by the so-called ,crook-and-swindle' business of art. In Duchamp's television interview with Mike Wallace that aired in New York on 18 January 1961, which is transcribed for the first time in English in this article, the ,crook-and-swindle, business of art, especially about modern art, takes centre stage, as the artist comments on numerous artists and critics, and reflects on his own artistic production, relationship to the art market and celebrity status. [source] Cold War Illuminations of the Classical Past: ,The Sound and Light Show, on the Athenian AcropolisART HISTORY, Issue 4 2001Elisabeth MarloweArticle first published online: 23 DEC 200 Drawing upon the text of ,The Sound and Light Show' and French and Greek newspaper coverage of the show's premier in 1959, this article uses the metaphor of the museum to consider the ways in which the show limits and controls the history that the Acropolis monuments are allowed to represent. I argue that the show's premise of a causal link between the defeat of tyrannical Eastern enemies and the flourishing of democracy and the arts is a product of the Cold War. This ideological backdrop can be traced through the dramatic events surrounding the show's star-studded, international premier and the richly nuanced political controversies that it reflected and in turn provoked. [source] COALITIONS AMONG INTELLIGENT AGENTS: A TRACTABLE CASECOMPUTATIONAL INTELLIGENCE, Issue 1 2006M. V. Belmonte Coalition formation is an important mechanism for cooperation in multiagent systems. In this paper we address the problem of coalition formation among self-interested agents in superadditive task-oriented domains. We assume that each agent has some "structure," i.e., that it can be described by the values taken by a set of m nonnegative attributes that represent the resources w each agent is endowed with. By defining the coalitional value as a function V of w, we prove a sufficient condition for the existence of a stable payment configuration,in the sense of the core,in terms of certain properties of V. We apply these ideas to a simple case that can be described by a linear program and show that it is possible to compute for it,in polynomial time,an optimal task allocation and a stable payment configuration. [source] A social agent pedestrian modelCOMPUTER ANIMATION AND VIRTUAL WORLDS (PREV: JNL OF VISUALISATION & COMPUTER ANIMATION), Issue 3-4 2008Andrew Park Abstract This paper presents a social agent pedestrian model based on experiments with human subjects. Research studies of criminology and environmental psychology show that certain features of the urban environment generate fear in people, causing them to take alternate routes. The Crime Prevention Through Environmental Design (CPTED) strategy has been implemented to reduce fear of crime and crime itself. Our initial prototype of a pedestrian model was developed based on these findings of criminology research. In the course of validating our model, we constructed a virtual environment (VE) that resembles a well-known fear-generating area where several decision points were set up. 60 human subjects were invited to navigate the VE and their choices of routes and comments during the post interviews were analyzed using statistical techniques and content analysis. Through our experimental results, we gained new insights into pedestrians' behavior and suggest a new enhanced and articulated agent model of a pedestrian. Our research not only provides a realistic pedestrian model, but also a new methodology for criminology research. Copyright © 2008 John Wiley & Sons, Ltd. [source] Exact and Robust (Self-)Intersections for Polygonal MeshesCOMPUTER GRAPHICS FORUM, Issue 2 2010Marcel Campen Abstract We present a new technique to implement operators that modify the topology of polygonal meshes at intersections and self-intersections. Depending on the modification strategy, this effectively results in operators for Boolean combinations or for the construction of outer hulls that are suited for mesh repair tasks and accurate mesh-based front tracking of deformable materials that split and merge. By combining an adaptive octree with nested binary space partitions (BSP), we can guarantee exactness (= correctness) and robustness (= completeness) of the algorithm while still achieving higher performance and less memory consumption than previous approaches. The efficiency and scalability in terms of runtime and memory is obtained by an operation localization scheme. We restrict the essential computations to those cells in the adaptive octree where intersections actually occur. Within those critical cells, we convert the input geometry into a plane-based BSP-representation which allows us to perform all computations exactly even with fixed precision arithmetics. We carefully analyze the precision requirements of the involved geometric data and predicates in order to guarantee correctness and show how minimal input mesh quantization can be used to safely rely on computations with standard floating point numbers. We properly evaluate our method with respect to precision, robustness, and efficiency. [source] Transferring the Rig and Animations from a Character to Different Face ModelsCOMPUTER GRAPHICS FORUM, Issue 8 2008Verónica Costa Orvalho I.3.7 Computer Graphics: Three-Dimensional Graphics and Realism. Animation Abstract We introduce a facial deformation system that allows artists to define and customize a facial rig and later apply the same rig to different face models. The method uses a set of landmarks that define specific facial features and deforms the rig anthropometrically. We find the correspondence of the main attributes of a source rig, transfer them to different three-demensional (3D) face models and automatically generate a sophisticated facial rig. The method is general and can be used with any type of rig configuration. We show how the landmarks, combined with other deformation methods, can adapt different influence objects (NURBS surfaces, polygon surfaces, lattice) and skeletons from a source rig to individual face models, allowing high quality geometric or physically-based animations. We describe how it is possible to deform the source facial rig, apply the same deformation parameters to different face models and obtain unique expressions. We enable reusing of existing animation scripts and show how shapes nicely mix one with the other in different face models. We describe how our method can easily be integrated in an animation pipeline. We end with the results of tests done with major film and game companies to show the strength of our proposal. [source] Recent Developments and Applications of Haptic DevicesCOMPUTER GRAPHICS FORUM, Issue 2 2003S. D. Laycock Abstract Over recent years a variety of haptic feedback devices have been developed and are being used in a number of important applications. They range from joysticks used in the entertainment industry to specialised devices used in medical applications. This paper will describe the recent developments of these devices and show how they have been applied. It also examines how haptic feedback has been combined with visual display devices, such as virtual reality walls and workbenches, in order to improve the immersive experience. ACM CSS: H.5.2 Information Interfaces and Presentation,Haptic I/O; I.3.8 Computer Graphics,Applications; I.6 Simulation and Modelling,Applications [source] Estimation of Frequency-Dependent Strong Motion Duration Via Wavelets and Its Influence on Nonlinear Seismic ResponseCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 4 2008Luis A. Montejo The proposed procedure utilizes the continuous wavelet transform and is based on the decomposition of the earthquake record into a number of component time histories (named "pseudo-details") with frequency content in a selected range. The "significant" strong motion duration of each pseudo-detail is calculated based on the accumulation of the Arias intensity (AI). Finally, the FDSMD of the earthquake record in different frequency ranges is defined as the strong motion duration of the corresponding pseudo-detail scaled by a weight factor that depends on the AI of each pseudo-detail. The efficiency of this new strong motion definition as an intensity measure is evaluated using incremental dynamic analysis (IDA). The results obtained show that the proposed FDSMD influence the peak response of short-period structures with stiffness and strength degradation. [source] An Ultrasonic Profiling Method for the Inspection of Tubular StructuresCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 6 2007Francisco Gomez These graphs not only show the inner contour of the pipe but also integrate the intensity of the echoes employed to create the profile. The enhanced profile is generated by superimposing the peak intensity from the returning echoes at the calculated x, y, and z coordinates where it reflected from the pipe wall. The proposed method is capable of showing anomalous conditions, inside pipes filled with liquid, with dimensions smaller than the theoretical lateral and axial resolution of the transducer, in contrast to traditional methods where these kinds of defects are not disclosed. The proposed inspection method and its capabilities were validated through the realization of simulations and experiments. The presented approach was particularly developed with the aim of scanning internal sections of pipes filled with liquid using rotary ultrasonic sonars, but it is expected that this research could be expanded to the inspection of other submerged structures, such as water tanks, or pressurized vessels. [source] Optimizing the point spread function in phase-encoded magnetic resonance microscopyCONCEPTS IN MAGNETIC RESONANCE, Issue 1 2004A.G. Webb Abstract Three-dimensional phase-encoded magnetic resonance microscopy is the most promising method for obtaining images with isotropic spatial resolutions on the order of a few micrometers. The attainable spatial resolution is limited by the available gradient strength (Gmax) and the molecular self-diffusion coefficient (D) of the sample. In this study, numerical simulations in the microscopic-size regime are presented in order to show that for given values of Gmax and D, there exists an optimum number of phase-encoding steps that maximize the spatial resolution in terms of minimizing the full-width at half-maximum (FWHM) of the image point spread function (PSF). Unlike the case of "macroscopic" imaging, in which diffusion plays an insignificant role in determining spatial resolution, acquiring data beyond this optimal value actually degrades the image PSF. An alternative version of phase encoding, using a variable phase-encoding time rather than a variable gradient strength, is analyzed in terms of improvements in the image PSF and/or reductions in the data acquisition time for a given spatial resolution. © 2004 Wiley Periodicals, Inc. Concepts Magn Reson 22A: 25,36, 2004. [source] A decentralized and fault-tolerant Desktop Grid system for distributed applications,CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 3 2010Heithem Abbes Abstract This paper proposes a decentralized and fault-tolerant software system for the purpose of managing Desktop Grid resources. Its main design principle is to eliminate the need for a centralized server, therefore to remove the single point of failure and bottleneck of existing Desktop Grids. Instead, each node can play alternatively the role of client or server. Our main contribution is to design the PastryGrid protocol (based on Pastry) for Desktop Grid in order to support a wider class of applications, especially the distributed application with precedence between tasks. Compared with a centralized system, we evaluate our approach over 205 machines executing 2500 tasks. The results we obtain show that our decentralized system outperforms XtremWeb-CH which is configured as a master/slave, with respect to the turnaround time. Copyright © 2009 John Wiley & Sons, Ltd. [source] Network-aware selective job checkpoint and migration to enhance co-allocation in multi-cluster systems,CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 13 2009William M. Jones Abstract Multi-site parallel job schedulers can improve average job turn-around time by making use of fragmented node resources available throughout the grid. By mapping jobs across potentially many clusters, jobs that would otherwise wait in the queue for local resources can begin execution much earlier; thereby improving system utilization and reducing average queue waiting time. Recent research in this area of scheduling leverages user-provided estimates of job communication characteristics to more effectively partition the job across system resources. In this paper, we address the impact of inaccuracies in these estimates on system performance and show that multi-site scheduling techniques benefit from these estimates, even in the presence of considerable inaccuracy. While these results are encouraging, there are instances where these errors result in poor job scheduling decisions that cause network over-subscription. This situation can lead to significantly degraded application performance and turnaround time. Consequently, we explore the use of job checkpointing, termination, migration, and restart (CTMR) to selectively stop offending jobs to alleviate network congestion and subsequently restart them when (and where) sufficient network resources are available. We then characterize the conditions and the extent to which the process of CTMR improves overall performance. We demonstrate that this technique is beneficial even when the overhead of doing so is costly. Copyright © 2009 John Wiley & Sons, Ltd. [source] Eye gaze in virtual environments: evaluating the need and initial work on implementationCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 11 2009Norman Murray Abstract For efficient collaboration between participants, eye gaze is seen as being critical for interaction. Video conferencing either does not attempt to support eye gaze (e.g. AcessGrid) or only approximates it in round table conditions (e.g. life size telepresence). Immersive collaborative virtual environments represent remote participants through avatars that follow their tracked movements. By additionally tracking people's eyes and representing their movement on their avatars, the line of gaze can be faithfully reproduced, as opposed to approximated. This paper presents the results of initial work that tested if the focus of gaze could be more accurately gauged if tracked eye movement was added to that of the head of an avatar observed in an immersive VE. An experiment was conducted to assess the difference between user's abilities to judge what objects an avatar is looking at with only head movements being displayed, while the eyes remained static, and with eye gaze and head movement information being displayed. The results from the experiment show that eye gaze is of vital importance to the subjects correctly identifying what a person is looking at in an immersive virtual environment. This is followed by a description of the work that is now being undertaken following the positive results from the experiment. We discuss the integration of an eye tracker more suitable for immersive mobile use and the software and techniques that were developed to integrate the user's real-world eye movements into calibrated eye gaze in an immersive virtual world. This is to be used in the creation of an immersive collaborative virtual environment supporting eye gaze and its ongoing experiments. Copyright © 2009 John Wiley & Sons, Ltd. [source] Dynamic data replication in LCG 2008CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 11 2008C. Nicholson Abstract To provide performance access to data from high-energy physics experiments such as the Large Hadron Collider (LHC), controlled replication of files among grid sites is required. Dynamic, automated replication in response to jobs may also be useful and has been investigated using the grid simulator OptorSim. In this paper, results are presented from simulations of the LHC Computing Grid in 2008, in a physics analysis scenario. These show, first, that dynamic replication does give improved job throughput; second, that for this complex grid system, simple replication strategies such as Least Recently Used and Least Frequently Used are as effective as more advanced economic models; third, that grid site policies that allow maximum resource sharing are more effective; and lastly, that dynamic replication is particularly effective when data access patterns include some files being accessed more often than others, such as with a Zipf-like distribution. Copyright © 2008 John Wiley & Sons, Ltd. [source] DS/CDMA throughput of a multi-hop sensor network in a Rayleigh fading underwater acoustic channelCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 8 2007Choong Hock Mar Abstract Asynchronous half-duplex Direct-Sequence Code-Division Multiple-Access (DS/CDMA) is a suitable candidate for the MAC protocol design of underwater acoustic (UWA) sensor networks owing to its many attractive features. Our ad-hoc multi-hop network is infrastructureless in that it is without centralized base stations or power control. Hence, we develop an asynchronous distributed half-duplex control protocol to regulate between the transmitting and receiving phases of transmissions. Furthermore, multi-hop communications are very sensitive to the time variability of the received signal strength in the fading channel and the ambient noise dominated by snapping shrimp in harsh underwater environments, because a broken link in the multi-hop path is enough to disrupt communications and initiate new route searches. In our configuration, we use the Ad hoc On-demand Distance Vector (AODV) routing protocol optimized for UWA networks. Empirical studies show that we can model the channel as a slow-varying frequency non-selective Rayleigh fading channel. We theoretically analyze the throughput of our configuration by considering three salient features: the ability of the receiver to demodulate the data, the effect of our control protocol and the effect of disconnections on the generation of routing packets. The throughput under various operating conditions is then examined. It is observed that at optimal node separation, the throughput is improved by a factor of 10. Copyright © 2007 John Wiley & Sons, Ltd. [source] Parallel divide-and-conquer scheme for 2D Delaunay triangulationCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 12 2006Min-Bin Chen Abstract This work describes a parallel divide-and-conquer Delaunay triangulation scheme. This algorithm finds the affected zone, which covers the triangulation and may be modified when two sub-block triangulations are merged. Finding the affected zone can reduce the amount of data required to be transmitted between processors. The time complexity of the divide-and-conquer scheme remains O(n log n), and the affected region can be located in O(n) time steps, where n denotes the number of points. The code was implemented with C, FORTRAN and MPI, making it portable to many computer systems. Experimental results on an IBM SP2 show that a parallel efficiency of 44,95% for general distributions can be attained on a 16-node distributed memory system. Copyright © 2006 John Wiley & Sons, Ltd. [source] Learning with an active e-course in the Knowledge Grid environmentCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 3 2006Hai Zhuge Abstract An active e-course is an open, self-representable and self-organizable media mechanism. Its kernel idea is to organize learning materials in a concept space rather than in a page space. The tailored content and flexible structure of the e-courses can be dynamically formed to cater for different learners with different backgrounds, capabilities and expectations, at different times and venues. The active e-course can also assess learners' learning performances and give appropriate suggestions to guide them in further learning. An authoring tool for constructing course ontology and a system prototype have been developed to support an active e-course, enabling a learner-centred, highly interactive and adaptive learning approach. The results of an empirical study show that the system can help enhance the effectiveness and efficiency of learning. Copyright © 2005 John Wiley & Sons, Ltd. [source] Fibre types in skeletal muscle: a personal accountACTA PHYSIOLOGICA, Issue 4 2010S. Schiaffino Abstract Muscle performance is in part dictated by muscle fibre composition and a precise understanding of the genetic and acquired factors that determine the fibre type profile is important in sport science, but is also relevant to neuromuscular diseases and to metabolic diseases, such as type 2 diabetes. The dissection of the signalling pathways that determine or modulate the muscle fibre phenotype has thus potential clinical significance. In this brief review, I examine the evolution of the notion of muscle fibre types, discuss some aspects related to species differences, point at problems in the interpretation of transgenic and knockout models and show how in vivo transfection can be used to identify regulatory factors involved in fibre type diversification, focusing on the calcineurin-nuclear factor of activated T cells (NFAT) pathway. [source] Prevalence of Sleep Disordered Breathing in a Heart Failure ProgramCONGESTIVE HEART FAILURE, Issue 5 2004Robin J. Trupp MSN Recent data show that a high percentage of patients with systolic left ventricular dysfunction have sleep-disordered breathing (SDB), contributing to the incidence of morbidity and mortality in heart failure. This study examines the prevalence of sleep disorders in stable heart failure patients regardless of ejection fraction. On three consecutive days in a heart failure clinic, all patients were asked to participate in a screening for SDB. This screening involved the placement of an outpatient device (ClearPath, Nexan, Inc., Alpharetta, GA), which collects thoracic impedance, oxyhemoglobin saturation, and 2-lead electrocardiogram data. Sixteen patients (42%) had moderate or severe SDB, and 22 patients (55%) had mild or no significant SDB. Fourteen of the 16 patients with moderate or severe SDB subsequently received treatment by confirming SDB and the continuous positive airway pressure in a sleep lab. Forty-two percent of patients with stable heart failure presenting to a heart failure clinic screened positive for SDB, despite receiving optimal standard of care. [source] Effects of Habitat Fragmentation on Effective Dispersal of Florida Scrub-JaysCONSERVATION BIOLOGY, Issue 4 2010AURÉLIE COULON Aphelocoma c,rulescens; dispersión; flujo génico; fragmentación Abstract:,Studies comparing dispersal in fragmented versus unfragmented landscapes show that habitat fragmentation alters the dispersal behavior of many species. We used two complementary approaches to explore Florida Scrub-Jay (Aphelocoma c,rulescens) dispersal in relation to landscape fragmentation. First, we compared dispersal distances of color-marked individuals in intensively monitored continuous and fragmented landscapes. Second, we estimated effective dispersal relative to the degree of fragmentation (as inferred from two landscape indexes: proportion of study site covered with Florida Scrub-Jay habitat and mean distance to nearest habitat patch within each study site) by comparing genetic isolation-by-distance regressions among 13 study sites having a range of landscape structures. Among color-banded individuals, dispersal distances were greater in fragmented versus continuous landscapes, a result consistent with other studies. Nevertheless, genetic analyses revealed that effective dispersal decreases as the proportion of habitat in the landscape decreases. These results suggest that although individual Florida Scrub-Jays may disperse farther as fragmentation increases, those that do so are less successful as breeders than those that disperse short distances. Our study highlights the importance of combining observational data with genetic inferences when evaluating the complex biological and life-history implications of dispersal. Resumen:,Estudios que comparan la dispersión en paisajes fragmentados versus no fragmentados muestran que la fragmentación del hábitat altera la conducta de dispersión de muchas especies. Utilizamos dos métodos complementarios para explorar la dispersión de Aphelocoma c,rulescens en relación con la fragmentación del paisaje. Primero, comparamos las distancias de dispersión de individuos marcados con color en paisajes continuos y fragmentados monitoreados intensivamente. Segundo, estimamos la dispersión efectiva en relación con el grado de fragmentación (inferida a partir de dos índices del paisaje: proporción del sitio de estudio cubierta con hábitat para A. c,rulescens y la distancia promedio al parche más cercano en cada sitio de estudio) mediante la comparación de regresiones de aislamiento genético por distancia entre 13 sitios de estudio con una gama de estructuras de paisaje. Entre los individuos marcados con color, las distancias de dispersión fueron mayores en los paisajes fragmentados versus los continuos, un resultado consistente con otros estudios. Sin embargo, los análisis genéticos revelaron que la dispersión efectiva decrece a medida que decrece la proporción de hábitat en el paisaje. Estos resultados sugieren que aunque individuos de A. c,rulescens pueden dispersarse más lejos a medida que incrementa la fragmentación, aquellos que lo hacen son reproductores menos exitosos que los que se dispersan a corta distancia. Nuestro estudio resalta la importancia de combinar datos observacionales con inferencias genéticas cuando se evalúan las complejas implicaciones de la dispersión sobre la biología y la historia natural. [source] The Conservation Relevance of Epidemiological Research into Carnivore Viral Diseases in the SerengetiCONSERVATION BIOLOGY, Issue 3 2007SARAH CLEAVELAND conservación de carnívoros; investigación epidemiológica; moquillo; rabia; Serengeti Abstract:,Recent outbreaks of rabies and canine distemper in wildlife populations of the Serengeti show that infectious disease constitutes a significant cause of mortality that can result in regional extirpation of endangered species even within large, well-protected areas. Nevertheless, effective management of an infectious disease depends critically on understanding the epidemiological dynamics of the causative pathogen. Pathogens with short infection cycles cannot persist in small populations in the absence of a more permanent reservoir of infection. Development of appropriate interventions requires detailed data on transmission pathways between reservoirs and wildlife populations of conservation concern. Relevant data can be derived from long-term population monitoring, epidemic and case-surveillance patterns, genetic analyses of rapidly evolving pathogens, serological surveys, and intervention studies. We examined studies of carnivore diseases in the Serengeti. Epidemiological research contributes to wildlife conservation policy in terms of management of endangered populations and the integration of wildlife conservation with public health interventions. Long-term, integrative, cross-species research is essential for formulation of effective policy for disease control and optimization of ecosystem health. Resumen:,Brotes recientes de rabia y moquillo en poblaciones silvestres del Serengeti muestran que las enfermedades infecciosas constituyen una causa significativa de mortandad que puede resultar en la extirpación regional de especies en peligro, aun en áreas extensas bien protegidas. Sin embargo, el manejo efectivo de una enfermedad infecciosa depende críticamente del entendimiento de la dinámica epidemiológica del patógeno. Los patógenos con ciclo infeccioso corto no pueden persistir en poblaciones pequeñas en ausencia de un reservorio de la infección más permanente. El desarrollo de intervenciones adecuadas requiere de datos detallados de las vías de transmisión entre reservorios y poblaciones de vida silvestre de preocupación para la conservación. Se pueden derivar datos importantes del monitoreo de poblaciones a largo plazo, de patrones de epidemias y de estudios de caso, del análisis genético de patógenos que evolucionan rápidamente, de muestreos sexológicos y de estudios de intervención. Examinamos estudios de enfermedades de carnívoros en el Serengeti. La investigación epidemiológica contribuye a las políticas de conservación de vida silvestre en términos de la gestión de poblaciones en peligro y de la integración de la conservación con intervenciones de salud pública. La investigación a largo plazo e integradora es esencial para la formulación de políticas efectivas para el control de enfermedades y la optimización de la salud del ecosistema. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||