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Kinds of Locations Terms modified by Locations Selected AbstractsA SIMPLE METHOD FOR ESTIMATING BASEFLOW AT UNGAGED LOCATIONS,JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 1 2001Kenneth W. Potter ABSTRACT: Baseflow, or water that enters a stream from slowly varying sources such as ground water, can be critical to humans and ecosystems. We evaluate a simple method for estimating base-flow parameters at ungaged sites. The method uses one or more baseflow discharge measurements at the ungaged site and longterm streamflow data from a nearby gaged site. A given baseflow parameter, such as the median, is estimated as the product of the corresponding gage site parameter and the geometric mean of the ratios of the measured baseflow discharges and the concurrent discharges at the gage site. If baseflows at gaged and ungaged sites have a bivariate lognormal distribution with high correlation and nearly equal log variances, the estimated baseflow parameters are very accurate. We tested the proposed method using long-term streamflow data from two watershed pairs in the Driftless Area of southwestern Wisconsin. For one watershed pair, the theoretical assumptions are well met; for the other the log-variances are substantially different. In the first case, the method performs well for estimating both annual and long-term baseflow parameters. In the second, the method performs remarkably well for estimating annual mean and annual median baseflow discharge, but less well for estimating the annual lower decile and the long-term mean, median, and lower decile. In general, the use of four measurements in a year is not substantially better than the use of two. [source] Characteristics of Important Stopover Locations for Migrating Birds: Remote Sensing with Radar in the Great Lakes BasinCONSERVATION BIOLOGY, Issue 2 2009DAVID N. BONTER ave terrestre migratoria; migración; radar; sitios de escala temporal; WSR-88D Abstract:,A preliminary stage in developing comprehensive conservation plans involves identifying areas used by the organisms of interest. The areas used by migratory land birds during temporal breaks in migration (stopover periods) have received relatively little research and conservation attention. Methodologies for identifying stopover sites across large geographic areas have been, until recently, unavailable. Advances in weather-radar technology now allow for evaluation of bird migration patterns at large spatial scales. We analyzed radar data (WSR-88D) recorded during spring migration in 2000 and 2001 at 6 sites in the Great Lakes basin (U.S.A.). Our goal was to link areas of high migrant activity with the land-cover types and landscape contexts corresponding to those areas. To characterize the landscapes surrounding stopover locations, we integrated radar and land-cover data within a geographic information system. We compared landscape metrics within 5 km of areas that consistently hosted large numbers of migrants with landscapes surrounding randomly selected areas that were used by relatively few birds during migration. Concentration areas were characterized by 1.2 times more forest cover and 9.3 times more water cover than areas with little migrant activity. We detected a strong negative relationship between activity of migratory birds and agricultural land uses. Examination of individual migration events confirmed the importance of fragments of forested habitat in highly altered landscapes and highlighted large concentrations of birds departing from near-shore terrestrial areas in the Great Lakes basin. We conclude that conservation efforts can be more effectively targeted through intensive analysis of radar imagery. Resumen:,Una etapa preliminar en el desarrollo de planes de conservación integrales implica la identificación de áreas utilizadas por los organismos de interés. Las áreas utilizadas por aves terrestres migratorias durante escalas temporales en la migración (períodos de parada) han recibido relativamente poca atención de investigación y conservación. Hasta hace poco, las metodologías para la identificación de sitios de parada en áreas geográficas extensas han sido escasas. Ahora, los avances en la tecnología de radar meteorológico permiten la evaluación de patrones de migración de aves en escalas espaciales grandes. Analizamos datos de radar (WSR-88D) registrados en seis sitios en la cuenca de los Grandes Lagos (E.U.A.) durante la migración en las primaveras de 2000 y 2001. Nuestra meta fue relacionar áreas con gran actividad migratoria con los tipos de cobertura de suelo y los contextos del paisaje correspondientes a esas áreas. Para caracterizar los paisajes circundantes a las localidades de parada, integramos los datos de radar y de cobertura de suelo a un sistema de información geográfica. Comparamos las medidas del paisaje en un radio de 5 km en las áreas que consistentemente albergaron a grandes números de migrantes con los paisajes circundantes a áreas seleccionadas aleatoriamente y que eran utilizadas por relativamente pocas aves durante la migración. Las áreas de concentración se caracterizaron por tener 1.3 veces más cobertura forestal y 9.3 veces más cobertura de agua que las áreas con poca actividad migratoria. Detectamos una fuerte relación negativa entre la actividad de las aves migratorias y los usos de suelo agrícolas. El examen de eventos migratorios individuales confirmó la importancia de los fragmentos de hábitat boscoso en paisajes muy alterados y resaltó las grandes concentraciones de aves partiendo de áreas terrestres cercanas a la costa en la cuenca de los Grandes Lagos. Concluimos que los esfuerzos de conservación pueden ser abordados más efectivamente mediante el análisis intensivo de imágenes de radar. [source] Physiological and Behavioral Differences in Magellanic Penguin Chicks in Undisturbed and Tourist-Visited Locations of a ColonyCONSERVATION BIOLOGY, Issue 5 2005BRIAN G. WALKER corticoesterona; ecoturismo; perturbación humana; Spheniscus magellanicus Abstract:,Studies examining anthropogenic effects on wildlife typically focus on adults and on behavioral responses rather than the physiological consequences of human disturbances. Here we examined how Magellanic Penguin ( Spheniscus magellanicus) chicks living in either tourist-visited or undisturbed areas of a breeding colony were affected by human visitation by comparing the baseline and stress-induced levels of corticosterone during three periods of the breeding season. Newly hatched chicks in visited areas had higher corticosterone stress responses than newly hatched chicks in undisturbed areas (p =0.007), but baseline levels were similar (p =0.61). By 40,50 days of age and around fledging time, both visited and undisturbed chicks showed a robust corticosterone stress response to capture. Tourist-visited chicks did not flee when approached by humans, however, whereas undisturbed chicks fled significantly sooner (i.e., when approached no closer than 9 m; p < 0.0001). Although it is unknown whether Magellanic Penguin chicks raised in visited areas suffer negative consequences from the elevation of the corticosterone stress response at hatching, they do exhibit behavioral habituation to human contact by the time they are ready to fledge. Unlike adults living in tourist areas, however, fledging chicks in visited areas do not have a decreased stress response to capture and restraint. Our results show that the coupling of behavioral and physiological habituation in Magellanic Penguins is complex and life-history context may greatly affect the ability of wildlife to adapt to anthropogenic disturbances. Resumen:,Los estudios de los efectos antropogénicos sobre la vida silvestre se centran típicamente en adultos y en las respuestas conductuales en lugar de las consecuencias fisiológicas de las perturbaciones humanas. Aquí examinamos el efecto de la visita de humanos sobre pollos de pingüino (Spheniscus magellanicus) en áreas visitadas por turistas o no perturbadas mediante la comparación de los niveles, base e inducidos por estrés, de corticoesterona durante tres períodos de la temporada reproductiva. Los pollos recién eclosionados en áreas visitadas tuvieron mayor respuesta de la corticoesterona al estrés que los pollos recién eclosionados en áreas no perturbadas (p =0.007), pero los niveles básicos fueron similares (p =0.61). A los 40,50 días y en la etapa de volantón, los pollos visitados y no perturbados mostraron una marcada respuesta de la corticoesterona al estrés al ser capturados. Sin embargo, los pollos visitados por turistas no huyeron cuando se les acercaron humanos, mientras que los pollos no perturbados huyeron significativamente antes (i.e., acercamiento a más de 9 m; p < 0.0001). Aunque se desconoce si los pollos de pingüino criados en áreas visitadas sufren consecuencias negativas por la elevación de la corticosterona en respuesta al estrés al eclosionar, si presentan acostumbramiento conductual al contacto con humanos al momento que están listos para dejar el nido. Sin embargo, a diferencia de adultos que viven en áreas turísticas, los pollos volantones en las áreas visitadas no tienen una disminución en la respuesta al estrés cuando son capturados y sujetados. Nuestros resultados muestran la complejidad de la combinación del acostumbramiento conductual y fisiológico en Spheniscus magellanicus y que el contexto de la historia de vida puede afectar a la habilidad de la vida silvestre para adaptarse a las perturbaciones antropogénicas. [source] Geckos as indicators of mining pollutionENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 9 2006Dean E. Fletcher Abstract Catastrophic collapse of a mine tailings dam released several million cubic meters of toxic mud and acidic water into the Guadiamar River valley, southern Spain, in 1998. Remediation efforts removed most of the sludge from the floodplain, but contamination persists. Clean-up activities also produced clouds of aerosolized materials that further contaminated the surrounding landscape. Whole-body concentrations of 21 elements in the Moorish wall gecko, Tarentola mauritanica, a common inhabitant of both rural and urban areas, were compared among seven locations. Locations spanned an expected contamination gradient and included a rural and an urban non,mine-affected location, two mine-affected towns, and three locations on the contaminated floodplain. Multivariate analyses of whole-body concentrations identified pollutants that increased across the expected contamination gradient, a trend particularly evident for As, Pb, and Cd. Additionally, higher contaminant concentrations occurred in prey items eaten by geckos from mine-affected areas. Comparison of element concentrations in tails and whole bodies suggests that tail clips are a viable nondestructive index of contaminant accumulation. Our results indicate that areas polluted by the mine continue to experience contamination of the terrestrial food chain. Where abundant, geckos represent useful taxa to study the bioavailability of some hazardous pollutants. [source] Resisting the Historical Locations of Tunisian Women MusiciansGENDER & HISTORY, Issue 2 2000Laura Lengel First page of article [source] The Swedish Deep Drilling Program: the quest for the Earth's inner secretsGEOLOGY TODAY, Issue 6 2009Henning Lorenz The Swedish Deep Drilling Program (SDDP) has been initiated to study fundamental problems of the dynamic Earth system, its natural history and evolution. Many key scientific questions can be addressed through in situ investigations only, requiring deep continental drilling. Some are unique to Scandinavia, most are of international interest and significance. At present, five core projects (Fig. 1) with international teams are integrating scientific problems with societal and industrial applications. If SDDP succeeds to attract the funding required, Sweden will have a number of world-class boreholes at key locations by 2020. Figure 1. Locations of SDDP drilling project proposals. PFDP,Postglacial Fault Drilling Project; PaMVAS,Palaeoproterozoic mineralized volcanic arc systems: the Skellefte District; COSC,Collisional Orogeny in the Scandinavian Caledonides; DRL,The Dellen Impact Crater, a geoscientific deep rock laboratory; SELHO,Svecofennian accretion, an example of the early structural evolution in a large hot orogen; CISP,Concentric Impact Structures in the Palaeozoic: the Lockne and Siljan craters. Background and inset image from Blue Marble Next Generation data set (NASA Earth Observatory, http://earthobservatory.nasa.gov/Features/BlueMarble/). [source] Does urbanization decrease diversity in ground beetle (Carabidae) assemblages?GLOBAL ECOLOGY, Issue 1 2010Tibor Magura ABSTRACT Aim, We wanted to test whether urbanization has similar effects on biodiversity in different locations, comparing the responses of ground beetle (Coleoptera, Carabidae) assemblages with an urbanization gradient. We also wanted to see if urbanization had a homogenizing effect on ground beetle assemblages. Locations, Nine forested temperate locations in Europe, Canada and Japan. Methods, Published results of the Globenet Project were used. At all locations, three stages were identified: (1) a forested (rural) area, (2) a suburban area where the original forest was fragmented and isolated, and (3) remnants of the original forest in urban parks. These habitats formed an urbanization series. Study arrangements (number and operation of traps) and methods (pitfall trapping) were identical, conforming to the Globenet protocol. Assemblage composition and diversity patterns were evaluated. Diversity relationships were analysed by the Rényi diversity ordering method considering all ground beetles and , separately , the forest specialist species. Taxonomic homogenization was examined by multivariate methods using assemblage similarities. Results, Overall biodiversity (compared by species richness and diversity ordering) showed inconsistent trends by either urbanization intensity or by geographic position. However, when only forest species were compared, diversity was higher in the original rural (forested) areas than in urban forest fragments. Within-country similarities of carabid assemblages were always higher than within-urbanization stage similarities. Main conclusions, Urbanization does not appear to cause a decrease in ground beetle diversity per se. Forest species decline as urbanization intensifies but this trend is masked by an influx of non-forest species. The rural faunas were more similar to the urban ones within the same location than similar urbanization stages were to each other, indicating that urbanization did not homogenize the taxonomic composition of ground beetle faunas across the studied locations. [source] Small,Scale Entrepreneurship and Access to Capital in Peripheral Locations: An Empirical AnalysisGROWTH AND CHANGE, Issue 2 2002Daniel Felsenstein This paper presents an analysis of a public assistance program for small,scale entrepreneurship in peripheral areas. Public assistance compensates for market inefficiencies where the decision rules of financial institutions discriminate against otherwise viable small firms in capital markets. Lending institutions perceive high risk in providing debt capital when little information is present. Using empirical data from Israel, the determinants of this risk are estimated and the role of location in creating this information asymmetry is stressed. These results empirically establish that (1) location matters in determining the risk profile of the firm, (2) locationally targeted programs can reduce the information asymmetries that make peripheral firms unattractive to lenders, and (3) these programs can also generate positive welfare effects. Finally, there is speculation on the potential role of ICT (information and communications technology) in increasing the visibility of small firms in remote locations and creating a more symmetrical flow of information. [source] Methodology and Transport Medium for Collection of Helicobacter pylori on a String Test in Remote LocationsHELICOBACTER, Issue 6 2005Helen M. Windsor ABSTRACT Background.,Helicobacter pylori can be isolated from patients using the string test but contaminating oral and nasopharyngeal microflora need to be suppressed by rapid plating out onto selective culture media. Recently, use of this diagnostic method was enhanced by using a novel transport medium to collect specimens from subjects in a remote Australian clinic over 1300 km from the laboratory. Methods., Retrieved string tests were transported to the laboratory in chilled polystyrene boxes in 5 ml screw-cap bottles with 3 ml of a brain heart infusion broth plus antibiotics. These were 20 g/ml vancomycin, 10 g/ml trimethoprim, 10 g/ml cefsulodin, and 10 g/ml amphotericin B. A comparison was made between subjects who gargled with a chlorhexidine mouthwash before swallowing the string test and those who did not. Results., Forty-five urea breath test-positive subjects were tested and H. pylori was isolated from 34 of them. Successful culture was achieved from string tests that were in transit for up to 29 hours and where the maximum temperature in the transport box was 14 °C. The additional use of a mouthwash had a marked effect on the isolation rate. H. pylori was cultured from 75% of subjects who gargled but only from 39% who did not. Conclusions., This methodology and transport medium can broaden the use of the string test to more remote geographic areas where endoscopy is not feasible so that H. pylori isolates may still be obtained for diagnostic and epidemiologic studies. The value of this promising methodology of collection and transport should be assessed in a controlled study. [source] Integrated layout design of multi-component systemINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 6 2009Jihong Zhu Abstract A new integrated layout optimization method is proposed here for the design of multi-component systems. By introducing movable components into the design domain, the components layout and the supporting structural topology are optimized simultaneously. The developed design procedure mainly consists of three parts: (i) Introduction of non-overlap constraints between components. The finite circle method (FCM) is used to avoid the components overlaps and also overlaps between components and the design domain boundaries. (ii) Layout optimization of the components and supporting structure. Locations and orientations of the components are assumed as geometrical design variables for the optimal placement while topology design variables of the supporting structure are defined by the density points. Meanwhile, embedded meshing techniques are developed to take into account the finite element mesh change caused by the component movements. (iii) Consistent material interpolation scheme between element stiffness and inertial load. The commonly used solid isotropic material with penalization model is improved to avoid the singularity of localized deformation in the presence of design dependent loading when the element stiffness and the involved inertial load are weakened by the element material removal. Finally, to validate the proposed design procedure, a variety of multi-component system layout design problems are tested and solved on account of inertia loads and gravity center position constraint. Solutions are compared with traditional topology designs without component. Copyright © 2008 John Wiley & Sons, Ltd. [source] Molecular cold-adaptation: Comparative analysis of two homologous families of psychrophilic and mesophilic signal proteins of the protozoan ciliate, EuplotesIUBMB LIFE, Issue 8 2009Claudio Alimenti Locations of negatively charged and aromatic residues in En and Er pheromones. See Molecular Cold-adaptation: Comparative Analysis of Two Homologous Families of Psychrophilic and Mesophilic Signal Proteins of the Protozoan Ciliate, Euplotes by Alimenti et al., pp. 838,845 [source] Glacial refugia for summer-green trees in Europe and south-west Asia as proposed by ECHAM3 time-slice atmospheric model simulationsJOURNAL OF BIOGEOGRAPHY, Issue 12 2007Suzanne A. G. Leroy Abstract Aim, To generate maps of potential refugia for summer-green trees during the Last Glacial Maximum (LGM). Locations, Southern Europe and south-western Asia. Methods, Time-slice simulations of the atmospheric climate with the ECHAM3 model are used for the LGM. Limiting factors beyond which cool and warm groups of deciduous trees cannot grow (such as temperature in growing degree days, minimum monthly temperature and precipitation in summer) are chosen. A limited validation by fossil pollen and charcoal records from LGM sites was done. Results, Two sets of maps extending from Europe to the Caspian region for cool and warm summer-green trees are presented. Three criteria are combined using contour lines to indicate confidence levels. Small areas within the three southern peninsulas of Europe (Spain, Italy and Greece) are highlighted as possible refugia for summer-green trees. Further, areas that have remained poorly known are now proposed as refugia, including the Sakarya,Kerempe region in northern Turkey, the east coast of the Black Sea and the area south of the Caspian Sea. Main conclusions, The maps produced in this study could be used to facilitate better long-term management for the protection of European and south-western Asian biodiversity. [source] Inter-ocean dispersal is an important mechanism in the zoogeography of hakes (Pisces: Merluccius spp.)JOURNAL OF BIOGEOGRAPHY, Issue 6 2001W. Stewart Grant Aim To present new genetic data and to review available published genetic data that bear on the phylogeny of hakes in the genus Merluccius. To construct a zoogeographical model from a summary phylogenetic tree with dated nodes. To search for an explanation of antitropical distributions in hakes. To assess peripheral isolate, centrifugal and vicariance models of speciation in view of the molecular phylogeny and zoogeography of hakes. Locations Northern and southern Atlantic Ocean, eastern Pacific Ocean, South Pacific Ocean. Methods Electrophoretic analysis of 20 allozyme loci in 10 species of hakes. Phylogenetic tree construction with parsimony and bootstrap methods. Reanalysis of previous genetic data. Analysis of zoogeographical patterns with geographical distributions of molecular genetic markers. Results Phylogenetic analyses of new and previous allozyme data and previous mitochondrial DNA data indicate a deep genetic partition between Old- and New-World hakes with genetic distances corresponding to 10,15 Myr of separation. This time marks a widening rift between Europe and North America and a rapid drop in ocean temperatures that subdivided an ancestral population of North Atlantic hake. Two Old-World clades spanning the equator include pairs of sister taxa separated by tropical waters. Divergence times between these pairs of sister-taxa variously date to the early Pliocene and late Pleistocene. Amongst New-World hakes, pairs of sister taxa are separated by equatorial waters, by the Southern Ocean, and by the Panama Isthmus. These genetic separations reflect isolation by the rise of the Isthmus 3,4 Ma and by Pliocene and Pleistocene dispersals. Pairs of species occurring in sympatry or parapatry in six regions do not reflect sister-species relationships, but appear to reflect allopatric divergence and back dispersals of descendent species. Some geographically isolated regional populations originating within the last few hundreds of thousands of years merit subspecies designations. Conclusions Vicariance from tectonic movement of continental plates or ridge formation cannot account for the disjunct distributions of most hake sister taxa. Molecular genetic divergences place the origin of most hake species diversity in the last 2,3 Myr, a period of negligible tectonic activity. Distributions of many hake species appear to have resulted from dispersals and back dispersals across both warm equatorial waters and cool waters in the Southern Ocean, driven by oscillations in climate and ocean temperatures. Genetic and ecological divergence prevents hybridization and competitive exclusion between sympatric species pairs in six regions. Sister-taxa relationships and estimates of divergence are consistent with the modified peripheral isolate model of speciation in which vicariances, range expansions and contractions, dispersals and founder events lead to isolated populations that subsequently diverge to form new species. [source] Pain and Anatomical Locations of Radiofrequency Ablation as Predictors of Esophageal Temperature Rise During Pulmonary Vein IsolationJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 1 2008ARASH ARYANA M.D. Introduction: Esophageal temperature rise (ETR) during ablation inside left atrium has been reported as a marker for esophageal thermal injury. We sought to investigate the possible relationships between chest pain and ETR during radiofrequency (RF) ablation, and ETR and locations of RF application, in patients undergoing pulmonary vein (PV) isolation under moderate sedation. Methods and Results: We analyzed anatomical locations of each RF application and its association with esophageal temperature and presence/absence of pain. Data from 40 consecutive patients (mean age: 56 ± 10 years) were analyzed. There were a total of 4,071 RF applications resulting in 291 episodes of pain (7.1%) and 223 ETRs (5.5%). Thirty-five patients (87.5%) experienced at least one pain episode and 32 (80.0%) had at least one ETR. While 77.4% of posterior wall applications that caused pain also corresponded to an ETR (P < 0.0001), only 0.8% of pain-free posterior wall applications were associated with ETRs (P < 0.0001). The sensitivity and specificity of pain during ablation for ETR were 94% and 98%, respectively. No ETRs were observed during anterior wall applications. ETRs occurred more frequently during ablation on the left (86.1%) versus the right (13.9%), and in inferior (70.4%) versus superior (29.6%) segments. Conclusion: In patients undergoing PV isolation, ETR was encountered when ablating in the posterior left atrium with the distribution left > right and inferior > superior. Pain during ablation was associated with ETR, and lack of pain was strongly associated with absence of ETR. Pain during RF ablation may thus serve as a predictor of esophageal heating and potential injury. [source] NORTH ATLANTIC RIGHT WHALE DISTRIBUTION IN RELATION TO SEA-SURFACE TEMPERATURE IN THE SOUTHEASTERN UNITED STATES CALVING GROUNDSMARINE MAMMAL SCIENCE, Issue 2 2006Chérie A. Keller Abstract Standardized aerial surveys were used to document the winter (December,March) distribution of North Atlantic right whales in their calving area off the coasts of Georgia and northeastern Florida (1991,1998). Survey data were collected within four survey zones in and adjacent to federally designated critical habitat. These data, including whale-sighting locations and sampling effort, were used to describe right whale distribution in relation to sea-surface temperature (SST) from satellite-derived images. Locations where whales were sighted (n= 609) had an overall mean SST of 14.3°C ± 2.1° (range 8°,22°C). Data from two survey zones having sufficient data (including the "early warning system" (EWS) zone and the Florida nearshore) were pooled by season and stratified by month to investigate changes in monthly ambient SST and fine-scale distribution patterns of right whales in relation to SST within spatially explicit search areas. Using Monte Carlo techniques, SSTs and latitudes (means and standard deviations) of locations where whales were sighted were compared to a sampling distribution of each variable derived from daily-search areas. Overall, results support a nonrandom distribution of right whales in relation to SST: during resident months (January and February), whales exhibited low variability in observed SST and a suggested southward shift in whale distribution toward warmer SSTs in the EWS zone; while in the relatively warmer and southernmost survey zone (Florida nearshore), right whales were concentrated in the northern, cooler portion. Our results support that warm Gulf Stream waters, generally found south and east of delineated critical habitat, represent a thermal limit for right whales and play an important role in their distribution within the calving grounds. These results affirm the inclusion of SST in a multivariate predictive model for right whale distribution in their southeastern habitat. [source] Glacial refugia and recolonization pathways in the brown seaweed Fucus serratusMOLECULAR ECOLOGY, Issue 17 2007G. HOARAU Abstract The last glacial maximum (20 000,18 000 years ago) dramatically affected extant distributions of virtually all northern European biota. Locations of refugia and postglacial recolonization pathways were examined in Fucus serratus (Heterokontophyta; Fucaceae) using a highly variable intergenic spacer developed from the complete mitochondrial genome of Fucus vesiculosus. Over 1500 samples from the entire range of F. serratus were analysed using fluorescent single strand conformation polymorphism. A total of 28 mtDNA haplotypes was identified and sequenced. Three refugia were recognized based on high haplotype diversities and the presence of endemic haplotypes: southwest Ireland, the northern Brittany-Hurd Deep area of the English Channel, and the northwest Iberian Peninsula. The Irish refugium was the source for a recolonization sweep involving a single haplotype via northern Scotland and throughout Scandinavia, whereas recolonization from the Brittany-Hurd Deep refugium was more limited, probably because of unsuitable soft-bottom habitat in the Bay of Biscay and along the Belgian and Dutch coasts. The Iberian populations reflect a remnant refugium at the present,day southern boundary of the species range. A generalized skyline plot suggested exponential population expansion beginning in the mid-Pleistocene with maximal growth during the Eems interglacial 128 000,67 000 years ago, implying that the last glacial maximum mainly shaped population distributions rather than demography. [source] Improved Detection of Differentially Expressed Genes Through Incorporation of Gene LocationsBIOMETRICS, Issue 3 2009Guanghua Xiao Summary In determining differential expression in cDNA microarray experiments, the expression level of an individual gene is usually assumed to be independent of the expression levels of other genes, but many recent studies have shown that a gene's expression level tends to be similar to that of its neighbors on a chromosome, and differentially expressed (DE) genes are likely to form clusters of similar transcriptional activity along the chromosome. When modeled as a one-dimensional spatial series, the expression level of genes on the same chromosome frequently exhibit significant spatial correlation, reflecting spatial patterns in transcription. By modeling these spatial correlations, we can obtain improved estimates of transcript levels. Here, we demonstrate the existence of spatial correlations in transcriptional activity in the,Escherichia coli,(E. coli) chromosome across more than 50 experimental conditions. Based on this finding, we propose a hierarchical Bayesian model that borrows information from neighboring genes to improve the estimation of the expression level of a given gene and hence the detection of DE genes. Furthermore, we extend the model to account for the circular structure of,E. coli,chromosome and the intergenetic distance between gene neighbors. The simulation studies and analysis of real data examples in,E. coli,and yeast,Saccharomyces cerevisiae,show that the proposed method outperforms the commonly used significant analysis of microarray (SAM),t -statistic in detecting DE genes. [source] Reducing Ambulance Response Times Using Geospatial,Time Analysis of Ambulance DeploymentACADEMIC EMERGENCY MEDICINE, Issue 9 2010Marcus Eng Hock Ong MBBS (S'pore) ACADEMIC EMERGENCY MEDICINE 2010; 17:951,957 © 2010 by the Society for Academic Emergency Medicine Abstract Objectives:, This study aimed to determine if a deployment strategy based on geospatial,time analysis is able to reduce ambulance response times for out-of-hospital cardiac arrests (OOHCA) in an urban emergency medical services (EMS) system. Methods:, An observational prospective study examining geographic locations of all OOHCA in Singapore was conducted. Locations of cardiac arrests were spot-mapped using a geographic information system (GIS). A progressive strategy of satellite ambulance deployment was implemented, increasing ambulance bases from 17 to 32 locations. Variation in ambulance deployment according to demand, based on time of day, was also implemented. The total number of ambulances and crews remained constant over the study period. The main outcome measure was ambulance response times. Results:, From October 1, 2001, to October 14, 2004, a total of 2,428 OOHCA patients were enrolled into the study. Mean ± SD age for arrests was 60.6 ± 19.3 years with 68.0% male. The overall return of spontaneous circulation (ROSC) rate was 17.2% and survival to discharge rate was 1.6%. Response time decreased significantly as the number of fire stations/fire posts increased (Pearson ,2 = 108.70, df = 48, p < 0.001). Response times for OOHCA decreased from a monthly median of 10.1 minutes at the beginning to 7.1 minutes at the end of the study. Similarly, the proportion of cases with response times < 8 minutes increased from 22.3% to 47.3% and < 11 minutes from 57.6% to 77.5% at the end of the study. Conclusions:, A simple, relatively low-cost ambulance deployment strategy was associated with significantly reduced response times for OOHCA. Geospatial,time analysis can be a useful tool for EMS providers. [source] Mapping cityscapes into cyberspace for visualizationCOMPUTER ANIMATION AND VIRTUAL WORLDS (PREV: JNL OF VISUALISATION & COMPUTER ANIMATION), Issue 2 2005Jiang Yu Zheng Abstract This work establishes a cyberspace of a real urban area for visiting on the Internet. By registering entire scenes along every street and at many locations, viewers can visually travel around and find their destinations in cyberspace. The issues we discuss here are mapping of a large-scale area to image domains in a small amount of data, and effective display of the captured scenes for various applications. Route Panoramas captured along streets and panoramic views captured at widely opening sites are associated to a city map to provide navigation functions. This paper focuses on the properties of our extended images,route panorama, addressing the archiving process applied to an urban area, an environment developed to transmit image data as streaming media, and display for scene traversing on the WWW in real time. The created cyberspaces of urban areas have broad applications such as city tour, real estate searching, e-commerce, heritage preservation, urban planning and construction, and vehicle navigation. Copyright © 2005 John Wiley & Sons, Ltd. [source] A Bayesian Monte Carlo Approach to Global IlluminationCOMPUTER GRAPHICS FORUM, Issue 8 2009Jonathan Brouillat I.3.7 [Computer Graphics]: Three-Dimensional Graphics an Realism Abstract Most Monte Carlo rendering algorithms rely on importance sampling to reduce the variance of estimates. Importance sampling is efficient when the proposal sample distribution is well-suited to the form of the integrand but fails otherwise. The main reason is that the sample location information is not exploited. All sample values are given the same importance regardless of their proximity to one another. Two samples falling in a similar location will have equal importance whereas they are likely to contain redundant information. The Bayesian approach we propose in this paper uses both the location and value of the data to infer an integral value based on a prior probabilistic model of the integrand. The Bayesian estimate depends only on the sample values and locations, and not how these samples have been chosen. We show how this theory can be applied to the final gathering problem and present results that clearly demonstrate the benefits of Bayesian Monte Carlo. [source] Comparing Parameter Manipulation with Mouse, Pen, and Slider User InterfacesCOMPUTER GRAPHICS FORUM, Issue 3 2009Colin Swindells Abstract Visual fixation on one's tool(s) takes much attention away from one's primary task. Following the belief that the best tools ,disappear' and become invisible to the user, we present a study comparing visual fixations (eye gaze within locations on a graphical display) and performance for mouse, pen, and physical slider user interfaces. Participants conducted a controlled, yet representative, color matching task that required user interaction representative of many data exploration tasks such as parameter exploration of medical or fuel cell data. We demonstrate that users may spend up to 95% fewer visual fixations on physical sliders versus standard mouse and pen tools without any loss in performance for a generalized visual performance task. [source] Shrinkability Maps for Content-Aware Video ResizingCOMPUTER GRAPHICS FORUM, Issue 7 2008Yi-Fei Zhang Abstract A novel method is given for content-aware video resizing, i.e. targeting video to a new resolution (which may involve aspect ratio change) from the original. We precompute a per-pixel cumulative shrinkability map which takes into account both the importance of each pixel and the need for continuity in the resized result. (If both x and y resizing are required, two separate shrinkability maps are used, otherwise one suffices). A random walk model is used for efficient offline computation of the shrinkability maps. The latter are stored with the video to create a multi-sized video, which permits arbitrary-sized new versions of the video to be later very efficiently created in real-time, e.g. by a video-on-demand server supplying video streams to multiple devices with different resolutions. These shrinkability maps are highly compressible, so the resulting multi-sized videos are typically less than three times the size of the original compressed video. A scaling function operates on the multi-sized video, to give the new pixel locations in the result, giving a high-quality content-aware resized video. Despite the great efficiency and low storage requirements for our method, we produce results of comparable quality to state-of-the-art methods for content-aware image and video resizing. [source] Gradient-based Interpolation and Sampling for Real-time Rendering of Inhomogeneous, Single-scattering MediaCOMPUTER GRAPHICS FORUM, Issue 7 2008Zhong Ren Abstract We present a real-time rendering algorithm for inhomogeneous, single scattering media, where all-frequency shading effects such as glows, light shafts, and volumetric shadows can all be captured. The algorithm first computes source radiance at a small number of sample points in the medium, then interpolates these values at other points in the volume using a gradient-based scheme that is efficiently applied by sample splatting. The sample points are dynamically determined based on a recursive sample splitting procedure that adapts the number and locations of sample points for accurate and efficient reproduction of shading variations in the medium. The entire pipeline can be easily implemented on the GPU to achieve real-time performance for dynamic lighting and scenes. Rendering results of our method are shown to be comparable to those from ray tracing. [source] Control of Feature-point-driven Facial Animation Using a Hypothetical FaceCOMPUTER GRAPHICS FORUM, Issue 4 2001Ming-Shing Su A new approach to the generation of a feature-point-driven facial animation is presented. In the proposed approach, a hypothetical face is used to control the animation of a face model. The hypothetical face is constructed by connecting some predefined facial feature points to create a net so that each facet of the net is represented by a Coon's surface. Deformation of the face model is controlled by changing the shape of the hypothetical face, which is performed by changing the locations of feature points and their tangents. Experimental results show that this hypothetical-face-based method can generate facial expressions which are visually almost identical to those of a real face. [source] Traffic Estimation and Optimal Counting Location Without Path Enumeration Using Bayesian NetworksCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 3 2008Enrique Castillo A combination (bi-level) of an OD-pair matrix estimation model based on Bayesian networks, and a Wardrop-minimum-variance model, which identifies origins and destinations of link flows, is used to estimate OD-pair and unobserved link flows based on some observations of links and/or OD-pair flows. The Bayesian network model is also used to select the optimal number and locations of the links counters based on maximum correlation. Finally, the proposed methods are illustrated by their application to the Nguyen,Dupuis and the Ciudad Real networks. [source] Short-Term Traffic Volume Forecasting Using Kalman Filter with Discrete Wavelet DecompositionCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 5 2007Yuanchang Xie Short-term traffic volume data are often corrupted by local noises, which may significantly affect the prediction accuracy of short-term traffic volumes. Discrete wavelet decomposition analysis is used to divide the original data into several approximate and detailed data such that the Kalman filter model can then be applied to the denoised data and the prediction accuracy can be improved. Two types of wavelet Kalman filter models based on Daubechies 4 and Haar mother wavelets are investigated. Traffic volume data collected from four different locations are used for comparison in this study. The test results show that both proposed wavelet Kalman filter models outperform the direct Kalman filter model in terms of mean absolute percentage error and root mean square error. [source] Detecting Cycle Failures at Signalized Intersections Using Video Image ProcessingCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 6 2006Jianyang Zheng Cycle failure detection is essential for identifying signal control problems at intersections. However, typical traffic sensors do not have the capability of capturing cycle failures. In this article, we introduce an algorithm for traffic signal cycle failure detection using video image processing. A cycle failure for a particular movement occurs when at least one vehicle must wait through more than one red light to complete the intended movement. The proposed cycle failure algorithm was implemented using Microsoft Visual C#. The system was tested with field data at different locations and time periods. The test results show that the algorithm works favorably: the system captured all the cycle failures and generated only three false alarms, which is approximately 0.9% of the total cycles tested. [source] Case,Based Reasoning for Assessing Intelligent Transportation Systems BenefitsCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 3 2003Adel Sadek Existing transportation planning modeling tools have critical limitations with respect to assessing the benefits of intelligent transportation systems (ITS) deployment. In this article, we present a novel framework for developing modeling tools for quantifying ITS deployments benefits. This approach is based on using case,based reasoning (CBR), an artificial intelligence paradigm, to capture and organize the insights gained from running a dynamic traffic assignment (DTA) model. To demonstrate the feasibility of the approach, the study develops a prototype system for evaluating the benefits of diverting traffic away from incident locations using variable message signs. A real,world network from the Hartford area in Connecticut is used in developing the system. The performance of the prototype is evaluated by comparing its predictions to those obtained using a detailed DTA model. The prototype system is shown to yield solutions comparable to those obtained from the DTA model, thus demonstrating the feasibility of the approach. [source] A 3-D Graphical Database System for Landfill Operations Using GPSCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 5 2002H. Ping Tserng Landfill space is an important commodity for landfill companies. It is desirable to develop an efficient tool to assist space management and monitor space consumption. When recyclable wastes or particular waste materials need to be retrieved from the landfill site, the excavation operations become more difficult without an efficient tool to provide waste information (i.e., location and type). In this paper, a methodology and several algorithms are proposed to develop a 3-D graphical database system (GDS) for landfill operations. A 3-D GDS not only monitors the space consumption of a landfill site, but can also provide exact locations and types of compacted waste that would later benefit the landfill excavation operations or recycling programs after the waste is covered. [source] Significance of Modeling Error in Structural Parameter EstimationCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 1 2001Masoud Sanayei Structural health monitoring systems rely on algorithms to detect potential changes in structural parameters that may be indicative of damage. Parameter-estimation algorithms seek to identify changes in structural parameters by adjusting parameters of an a priori finite-element model of a structure to reconcile its response with a set of measured test data. Modeling error, represented as uncertainty in the parameters of a finite-element model of the structure, curtail capability of parameter estimation to capture the physical behavior of the structure. The performance of four error functions, two stiffness-based and two flexibility-based, is compared in the presence of modeling error in terms of the propagation rate of the modeling error and the quality of the final parameter estimates. Three different types of parameters are used in the parameter estimation procedure: (1) unknown parameters that are to be estimated, (2) known parameters assumed to be accurate, and (3) uncertain parameters that manifest the modeling error and are assumed known and not to be estimated. The significance of modeling error is investigated with respect to excitation and measurement type and locations, the type of error function, location of the uncertain parameter, and the selection of unknown parameters to be estimated. It is illustrated in two examples that the stiffness-based error functions perform significantly better than the corresponding flexibility-based error functions in the presence of modeling error. Additionally, the topology of the structure, excitation and measurement type and locations, and location of the uncertain parameters with respect to the unknown parameters can have a significant impact on the quality of the parameter estimates. Insight into the significance of modeling error and its potential impact on the resulting parameter estimates is presented through analytical and numerical examples using static and modal data. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||