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Sample records for dispersal interpatch movements

  1. Effects of corridors on home range sizes and interpatch movements of three small mammal species.

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    Mabry, Karen, E.; Barrett, Gary, W.

    2002-04-30

    Mabry, K.E., and G.W. Barrett. 2002. Effects of corridors on home range sizes and interpatch movements of three small mammal species. Landscape Ecol. 17:629-636. Corridors are predicted to benefit populations in patchy habitats by promoting movement, which should increase population densities, gene flow, and recolonization of extinct patch populations. However, few investigators have considered use of the total landscape, particularly the possibility of interpatch movement through matrix habitat, by small mammals. This study compares home range sizes of 3 species of small mammals, the cotton mouse, old field mouse and cotton rat between patches with and without corridors. Corridor presence did not have a statistically significant influence on average home range size. Habitat specialization and sex influenced the probability of an individual moving between 2 patches without corridors. The results of this study suggest that small mammals may be more capable of interpatch movement without corridors than is frequently assumed.

  2. Effects of matrix characteristics and interpatch distance on functional connectivity in fragmented temperate rainforests.

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    Magrach, Ainhoa; Larrinaga, Asier R; Santamaría, Luis

    2012-04-01

    The connectivity of remnant patches of habitat may affect the persistence of species in fragmented landscapes. We evaluated the effects of the structural connectivity of forest patches (i.e., distance between patches) and matrix class (land-cover type) on the functional connectivity of 3 bird species (the White-crested Elaenia [Elaenia albiceps], the Green-backed Firecrown Hummingbird [Sephanoides sephaniodes], and the Austral Thrush [Turdus falklandii]). We measured functional connectivity as the rate at which each species crossed from one patch to another. We also evaluated whether greater functional connectivity translated into greater ecological connectivity (dispersal of fruit and pollen) by comparing among forest patches fruit set of a plant pollinated by hummingbirds and abundance of seedlings and adults of 2 plants with bird- and wind-dispersed seeds. Interpatch distance was strongly associated with functional connectivity, but its effect was not independent of matrix class. For one of the bird-dispersed plants, greater functional connectivity for White-crested Elaenias and Austral Thrushes (both frugivores) was associated with higher densities of this plant. The lack of a similar association for the wind-dispersed species suggests this effect is linked to the dispersal vector. The abundance of the hummingbird-pollinated species was not related to the presence of hummingbirds. Interpatch distance and matrix class affect animal movement in fragmented landscapes and may have a cascading effect on the distribution of some animal-dispersed species. On the basis of our results, we believe effort should be invested in optimizing patch configuration and modifying the matrix so as to mitigate the effects of patch isolation in fragmented landscapes. ©2012 Society for Conservation Biology.

  3. Integrating individual movement behaviour into dispersal functions.

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    Heinz, Simone K; Wissel, Christian; Conradt, Larissa; Frank, Karin

    2007-04-21

    Dispersal functions are an important tool for integrating dispersal into complex models of population and metapopulation dynamics. Most approaches in the literature are very simple, with the dispersal functions containing only one or two parameters which summarise all the effects of movement behaviour as for example different movement patterns or different perceptual abilities. The summarising nature of these parameters makes assessing the effect of one particular behavioural aspect difficult. We present a way of integrating movement behavioural parameters into a particular dispersal function in a simple way. Using a spatial individual-based simulation model for simulating different movement behaviours, we derive fitting functions for the functional relationship between the parameters of the dispersal function and several details of movement behaviour. This is done for three different movement patterns (loops, Archimedean spirals, random walk). Additionally, we provide measures which characterise the shape of the dispersal function and are interpretable in terms of landscape connectivity. This allows an ecological interpretation of the relationships found.

  4. Social familiarity governs prey patch-exploitation, -leaving and inter-patch distribution of the group-living predatory mite Phytoseiulus persimilis.

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    Zach, Gernot J; Peneder, Stefan; Strodl, Markus A; Schausberger, Peter

    2012-01-01

    In group-living animals, social interactions and their effects on other life activities such as foraging are commonly determined by discrimination among group members. Accordingly, many group-living species evolved sophisticated social recognition abilities such as the ability to recognize familiar individuals, i.e. individuals encountered before. Social familiarity may affect within-group interactions and between-group movements. In environments with patchily distributed prey, group-living predators must repeatedly decide whether to stay with the group in a given prey patch or to leave and search for new prey patches and groups. Based on the assumption that in group-living animals social familiarity allows to optimize the performance in other tasks, as for example predicted by limited attention theory, we assessed the influence of social familiarity on prey patch exploitation, patch-leaving, and inter-patch distribution of the group-living, plant-inhabiting predatory mite Phytoseiulus persimilis. P. persimilis is highly specialized on herbivorous spider mite prey such as the two-spotted spider mite Tetranychus urticae, which is patchily distributed on its host plants. We conducted two experiments with (1) groups of juvenile P. persimilis under limited food on interconnected detached leaflets, and (2) groups of adult P. persimilis females under limited food on whole plants. Familiar individuals of both juvenile and adult predator groups were more exploratory and dispersed earlier from a given spider mite patch, occupied more leaves and depleted prey more quickly than individuals of unfamiliar groups. Moreover, familiar juvenile predators had higher survival chances than unfamiliar juveniles. We argue that patch-exploitation and -leaving, and inter-patch dispersion were more favorably coordinated in groups of familiar than unfamiliar predators, alleviating intraspecific competition and improving prey utilization and suppression.

  5. Social familiarity governs prey patch-exploitation, -leaving and inter-patch distribution of the group-living predatory mite Phytoseiulus persimilis.

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    Gernot J Zach

    Full Text Available In group-living animals, social interactions and their effects on other life activities such as foraging are commonly determined by discrimination among group members. Accordingly, many group-living species evolved sophisticated social recognition abilities such as the ability to recognize familiar individuals, i.e. individuals encountered before. Social familiarity may affect within-group interactions and between-group movements. In environments with patchily distributed prey, group-living predators must repeatedly decide whether to stay with the group in a given prey patch or to leave and search for new prey patches and groups.Based on the assumption that in group-living animals social familiarity allows to optimize the performance in other tasks, as for example predicted by limited attention theory, we assessed the influence of social familiarity on prey patch exploitation, patch-leaving, and inter-patch distribution of the group-living, plant-inhabiting predatory mite Phytoseiulus persimilis. P. persimilis is highly specialized on herbivorous spider mite prey such as the two-spotted spider mite Tetranychus urticae, which is patchily distributed on its host plants. We conducted two experiments with (1 groups of juvenile P. persimilis under limited food on interconnected detached leaflets, and (2 groups of adult P. persimilis females under limited food on whole plants. Familiar individuals of both juvenile and adult predator groups were more exploratory and dispersed earlier from a given spider mite patch, occupied more leaves and depleted prey more quickly than individuals of unfamiliar groups. Moreover, familiar juvenile predators had higher survival chances than unfamiliar juveniles.We argue that patch-exploitation and -leaving, and inter-patch dispersion were more favorably coordinated in groups of familiar than unfamiliar predators, alleviating intraspecific competition and improving prey utilization and suppression.

  6. High Emigration Propensity and Low Mortality on Transfer Drives Female-Biased Dispersal of Pyriglena leucoptera in Fragmented Landscapes.

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    Marcelo Awade

    Full Text Available Dispersal is a biological process performed in three stages: emigration, transfer and immigration. Intra-specific variation on dispersal behavior, such as sex-bias, is very common in nature, particularly in birds and mammals. However, dispersal is difficult to measure in the field and many hypotheses concerning the causes of sex-biased dispersal remain without empirical confirmation. An important limitation of most empirical studies is that inferences about sex-biased dispersal are based only on emigration proneness or immigration success data. Thus, we still do not know whether sex-biased immigration in fragmented landscapes occurs during emigration, transfer or in both stages. We conducted translocation and radiotracking experiments to assess i whether inter-patch dispersal movements of a rainforest bird (Pyriglena leucoptera is sex-biased and ii how dispersal stages and the perceptual range of the individuals are integrated to generate dispersal patterns. Our results showed that inter-patch dispersal is sex-biased at all stages for P. leucoptera, as females not only exhibit a higher emigration propensity but are subjected to a lower risk of predation when moving through the matrix. Moreover, our data support a perceptual range of 80 m and our results showed that dispersal success decreases considerably when inter-patch distances exceeds this perceptual range. In this case, birds have a higher probability of travelling over longer routes and, as a consequence, the risk of predation increases, specially for males. Overall, results supported that assuming dispersal as a single-stage process to describe dispersal behavior may be misleading. In this way, our study advanced our understanding of processes and patterns related to inter-patch dispersal of neotropical forest birds, shedding light on potential implications for population dynamics and for the management of fragmented landscapes.

  7. On the estimation of dispersal and movement of birds

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    Kendall, W.L.; Nichols, J.D.

    2004-01-01

    The estimation of dispersal and movement is important to evolutionary and population ecologists, as well as to wildlife managers. We review statistical methodology available to estimate movement probabilities. We begin with cases where individual birds can be marked and their movements estimated with the use of multisite capture-recapture methods. Movements can be monitored either directly, using telemetry, or by accounting for detection probability when conventional marks are used. When one or more sites are unobservable, telemetry, band recoveries, incidental observations, a closed- or open-population robust design, or partial determinism in movements can be used to estimate movement. When individuals cannot be marked, presence-absence data can be used to model changes in occupancy over time, providing indirect inferences about movement. Where abundance estimates over time are available for multiple sites, potential coupling of their dynamics can be investigated using linear cross-correlation or nonlinear dynamic tools.

  8. Dispersal, individual movement and spatial ecology a mathematical perspective

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    Maini, Philip; Petrovskii, Sergei

    2013-01-01

    Dispersal of plants and animals is one of the most fascinating subjects in ecology. It has long been recognized as an important factor affecting ecosystem dynamics. Dispersal is apparently a phenomenon of biological origin; however, because of its complexity, it cannot be studied comprehensively by biological methods alone. Deeper insights into dispersal properties and implications require interdisciplinary approaches involving biologists, ecologists and mathematicians. The purpose of this book is to provide a forum for researches with different backgrounds and expertise and to ensure further advances in the study of dispersal and spatial ecology. This book is unique in its attempt to give an overview of dispersal studies across different spatial scales, such as the scale of individual movement, the population scale and the scale of communities and ecosystems. It is written by top-level experts in the field of dispersal modeling and covers a wide range of problems ranging from the identification of Levy walks...

  9. Condition-dependent movement and dispersal in experimental metacommunities

    Czech Academy of Sciences Publication Activity Database

    Fronhofer, E. A.; Klečka, Jan; Melián, C. J.; Altermatt, F.

    2015-01-01

    Roč. 18, č. 9 (2015), s. 954-963 ISSN 1461-023X Grant - others:Sciex fellowship(CZ) 12.327 Institutional support: RVO:60077344 Keywords : allee effect * density-dependent dispersal * density-dependent movement Subject RIV: EH - Ecology, Behaviour Impact factor: 10.772, year: 2015 http://onlinelibrary.wiley.com/doi/10.1111/ele.12475/epdf

  10. Movements vary according to dispersal stage, group size, and rainfall: The case of the African lion

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    Nicholas B. Elliot; Samuel A. Cushman; Andrew J. Loveridge; Godfrey Mtare; David W. Macdonald

    2014-01-01

    Dispersal is one of the most important life-history traits affecting species persistence and evolution and is increasingly relevant for conservation biology as ecosystems become more fragmented. However, movement during different dispersal stages has been difficult to study and remains poorly understood. We analyzed movement metrics and patterns of autocorrelation from...

  11. Image quality assessment based on inter-patch and intra-patch similarity.

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    Fei Zhou

    Full Text Available In this paper, we propose a full-reference (FR image quality assessment (IQA scheme, which evaluates image fidelity from two aspects: the inter-patch similarity and the intra-patch similarity. The scheme is performed in a patch-wise fashion so that a quality map can be obtained. On one hand, we investigate the disparity between one image patch and its adjacent ones. This disparity is visually described by an inter-patch feature, where the hybrid effect of luminance masking and contrast masking is taken into account. The inter-patch similarity is further measured by modifying the normalized correlation coefficient (NCC. On the other hand, we also attach importance to the impact of image contents within one patch on the IQA problem. For the intra-patch feature, we consider image curvature as an important complement of image gradient. According to local image contents, the intra-patch similarity is measured by adaptively comparing image curvature and gradient. Besides, a nonlinear integration of the inter-patch and intra-patch similarity is presented to obtain an overall score of image quality. The experiments conducted on six publicly available image databases show that our scheme achieves better performance in comparison with several state-of-the-art schemes.

  12. Dispersion correction through movement of the closed orbit

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    Parzen, G.

    1980-01-01

    The closed orbit correction system can be used to correct the vertical dispersion by displacing the orbit at the quadrupoles and sextupoles. The accuracy of the results have been verified by comparison with exact calculations. Results for correcting the horizontal dispersion are also given

  13. Evaluation of the dispersion effect in through movement bicycles at signalized intersection via cellular automata simulation

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    Jiang, Hang; Ma, Yongjian; Jiang, Lin; Chen, Guozhou; Wang, Dongwei

    2018-05-01

    At signalized intersection areas, bicycle traffic presents a dispersion feature which may influence the movements of vehicles during peak period. The primary objective of this study is to simulate the dispersion effect in through-movement bicycle traffic at intersection areas and evaluate its influence on through-movement traffic. A cellular automata (CA) model is developed and validated to simulate the operations of through-movement bicycle traffic departing from two types of intersection approaches. Simulation results show that bicycles benefit from the dispersion effect when they depart from the approach with an exclusive right-turn vehicle lane. But when bicycles travel from the approach with a shared right-turn and through vehicle lane, the dispersion effect will result in friction interference and block interference on through-movement vehicles. Bicycle interferences reduce the vehicle speed and increase the delay of through-movement vehicles. The policy implications in regard to the dispersion effect from two types of approaches are discussed to improve the performance of through-movement traffic operations at signalized intersections.

  14. Effects of intra- and interpatch host density on egg parasitism by three species of Trichogramma.

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    Grieshop, Matthew J; Flinn, Paul W; Nechols, James R

    2010-01-01

    Host-foraging responses to different intra- and interpatch densities were used to assess three Trichogramma spp. (Hymenoptera: Trichogrammatidae) Trichogramma deion Pinto and Oatman, T. ostriniae Pang and Chen, and T. pretiosum Riley - as potential biological control agents for the Indian meal moth, Plodia interpunctella Hübner (Lepidoptera: Pyralidae). Single naïve females were allowed 6 h to forage in Plexiglas arenas with four different spatial arrangements of host eggs, nine single-egg patches), nine four-egg patches, 36 single-egg patches, and 36 four-egg patches. No significant differences were found among species in the number of patches parasitized. As expected, all three species parasitized the most eggs in the 36 four-egg patch treatment and the least in the nine single-egg patch treatment. T. deion parasitized significantly more eggs than T. pretiosum on the nine four-egg patches. T. ostriniae parasitized significantly more patches when intrapatch density was greater, regardless of interpatch density. In contrast, T. deion only parasitized more patches at the greater intrapatch density when the interpatch density was low. Patch density had no effect on T. pretiosum. The spatial pattern of parasitism was more aggregated for T. deion and T. ostriniae in the 36 four-egg patches treatment compared to the 36 single-egg patches treatment. Therefore, intrapatch density was more important than interpatch density for T. ostriniae, and potentially for T. deion, but not for T. pretiosum. T. deion may be the best candidate for augmentative biological control because it parasitized either slightly or significantly more eggs than the other two species in all four treatments. Furthermore, the pattern of parasitism by T. deion in the 36 four-egg patches treatment was the most aggregated among the three species, suggesting a more thorough searching pattern. In contrast, T. pretiosum had the least aggregated pattern of parasitism and therefore may have used a more

  15. Movement patterns and dispersal potential of Pecos bluntnose shiner (Notropis simus pecosensis) revealed using otolith microchemistry

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    Chase, Nathan M.; Caldwell, Colleen A.; Carleton, Scott A.; Gould, William R.; Hobbs, James A.

    2015-01-01

    Natal origin and dispersal potential of the federally threatened Pecos bluntnose shiner (Notropis simus pecosensis) were successfully characterized using otolith microchemistry and swimming performance trials. Strontium isotope ratios (87Sr:86Sr) of otoliths within the resident plains killifish (Fundulus zebrinus) were successfully used as a surrogate for strontium isotope ratios in water and revealed three isotopically distinct reaches throughout 297 km of the Pecos River, New Mexico, USA. Two different life history movement patterns were revealed in Pecos bluntnose shiner. Eggs and fry were either retained in upper river reaches or passively dispersed downriver followed by upriver movement during the first year of life, with some fish achieving a minimum movement of 56 km. Swimming ability of Pecos bluntnose shiner confirmed upper critical swimming speeds (Ucrit) as high as 43.8 cm·s−1 and 20.6 body lengths·s−1 in 30 days posthatch fish. Strong swimming ability early in life supports our observations of upriver movement using otolith microchemistry and confirms movement patterns that were previously unknown for the species. Understanding patterns of dispersal of this and other small-bodied fishes using otolith microchemistry may help redirect conservation and management efforts for Great Plains fishes.

  16. Should I stay or should I go? A habitat-dependent dispersal kernel improves prediction of movement.

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    Fabrice Vinatier

    Full Text Available The analysis of animal movement within different landscapes may increase our understanding of how landscape features affect the perceptual range of animals. Perceptual range is linked to movement probability of an animal via a dispersal kernel, the latter being generally considered as spatially invariant but could be spatially affected. We hypothesize that spatial plasticity of an animal's dispersal kernel could greatly modify its distribution in time and space. After radio tracking the movements of walking insects (Cosmopolites sordidus in banana plantations, we considered the movements of individuals as states of a Markov chain whose transition probabilities depended on the habitat characteristics of current and target locations. Combining a likelihood procedure and pattern-oriented modelling, we tested the hypothesis that dispersal kernel depended on habitat features. Our results were consistent with the concept that animal dispersal kernel depends on habitat features. Recognizing the plasticity of animal movement probabilities will provide insight into landscape-level ecological processes.

  17. Should I stay or should I go? A habitat-dependent dispersal kernel improves prediction of movement.

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    Vinatier, Fabrice; Lescourret, Françoise; Duyck, Pierre-François; Martin, Olivier; Senoussi, Rachid; Tixier, Philippe

    2011-01-01

    The analysis of animal movement within different landscapes may increase our understanding of how landscape features affect the perceptual range of animals. Perceptual range is linked to movement probability of an animal via a dispersal kernel, the latter being generally considered as spatially invariant but could be spatially affected. We hypothesize that spatial plasticity of an animal's dispersal kernel could greatly modify its distribution in time and space. After radio tracking the movements of walking insects (Cosmopolites sordidus) in banana plantations, we considered the movements of individuals as states of a Markov chain whose transition probabilities depended on the habitat characteristics of current and target locations. Combining a likelihood procedure and pattern-oriented modelling, we tested the hypothesis that dispersal kernel depended on habitat features. Our results were consistent with the concept that animal dispersal kernel depends on habitat features. Recognizing the plasticity of animal movement probabilities will provide insight into landscape-level ecological processes.

  18. Overland movement in African clawed frogs (Xenopus laevis: empirical dispersal data from within their native range

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    F. André De Villiers

    2017-11-01

    Full Text Available Dispersal forms are an important component of the ecology of many animals, and reach particular importance for predicting ranges of invasive species. African clawed frogs (Xenopus laevis move overland between water bodies, but all empirical studies are from invasive populations with none from their native southern Africa. Here we report on incidents of overland movement found through a capture-recapture study carried out over a three year period in Overstrand, South Africa. The maximum distance moved was 2.4 km with most of the 91 animals, representing 5% of the population, moving ∼150 m. We found no differences in distances moved by males and females, despite the former being smaller. Fewer males moved overland, but this was no different from the sex bias found in the population. In laboratory performance trials, we found that males outperformed females, in both distance moved and time to exhaustion, when corrected for size. Overland movement occurred throughout the year, but reached peaks in spring and early summer when temporary water bodies were drying. Despite permanent impoundments being located within the study area, we found no evidence for migrations of animals between temporary and permanent water bodies. Our study provides the first dispersal kernel for X. laevis and suggests that it is similar to many non-pipid anurans with respect to dispersal.

  19. Homogenization of a Directed Dispersal Model for Animal Movement in a Heterogeneous Environment.

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    Yurk, Brian P

    2016-10-01

    The dispersal patterns of animals moving through heterogeneous environments have important ecological and epidemiological consequences. In this work, we apply the method of homogenization to analyze an advection-diffusion (AD) model of directed movement in a one-dimensional environment in which the scale of the heterogeneity is small relative to the spatial scale of interest. We show that the large (slow) scale behavior is described by a constant-coefficient diffusion equation under certain assumptions about the fast-scale advection velocity, and we determine a formula for the slow-scale diffusion coefficient in terms of the fast-scale parameters. We extend the homogenization result to predict invasion speeds for an advection-diffusion-reaction (ADR) model with directed dispersal. For periodic environments, the homogenization approximation of the solution of the AD model compares favorably with numerical simulations. Invasion speed approximations for the ADR model also compare favorably with numerical simulations when the spatial period is sufficiently small.

  20. Persistence of long-distance, insect-mediated pollen movement for a tropical canopy tree species in remnant forest patches in an urban landscape.

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    Noreen, A M E; Niissalo, M A; Lum, S K Y; Webb, E L

    2016-12-01

    As deforestation and urbanization continue at rapid rates in tropical regions, urban forest patches are essential repositories of biodiversity. However, almost nothing is known about gene flow of forest-dependent tree species in urban landscapes. In this study, we investigated gene flow in the insect-pollinated, wind-dispersed tropical tree Koompassia malaccensis in and among three remnant forest patches in the urbanized landscape of Singapore. We genotyped the vast majority of adults (N=179) and a large number of recruits (N=2103) with 8 highly polymorphic microsatellite markers. Spatial genetic structure of the recruit and adult cohorts was significant, showing routine gene dispersal distances of ~100-400 m. Parentage analysis showed that 97% of recruits were within 100 m of their mother tree, and a high frequency of relatively short-distance pollen dispersal (median ~143-187 m). Despite routine seed and pollen dispersal distances of within a few hundred meters, interpatch gene flow occurred between all patches and was dominated by pollen movement: parentage analysis showed 76 pollen versus 2 seed interpatch dispersal events, and the seedling neighborhood model estimated ~1-6% seed immigration and ~21-46% pollen immigration rates, depending on patch. In addition, the smallest patch (containing five adult K. malaccensis trees) was entirely surrounded by >2.5 km of 'impervious' substrate, yet had the highest proportional pollen and seed immigration estimates of any patch. Hence, contrary to our hypothesis, insect-mediated gene flow persisted across an urban landscape, and several of our results also parallel key findings from insect-pollinated canopy trees sampled in mixed agricultural-forest landscapes.

  1. Evaluation of field-collected data measuring fluorescein dye movements and dispersion for dispersed oil transport modeling

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    French McCay, D.; Mueller, C.; Jayko, K.; Longval, B.; Schroeder, M. [Applied Science Associates Inc., Narragansett, RI (United States); Terrill, E.; Carter, M.; Otero, M.; Kim, S.Y. [Scripps Inst. of Oceanography, La Jolla, CA (United States); Nordhausen, W.; Lampinen, M. [California Dept. of Fish and Game, San Diego, CA (United States). Office of Spill Prevention and Response; Payne, J.R. [Payne Environmental Consultants Inc., Encinitas, CA (United States); Ohlmann, C. [California Univ., Santa Barbara, CA (United States)

    2007-07-01

    In the event of on oil spill at sea, the concentration of hydrocarbons in the water column can be evaluated using oil spill fate and transport modeling. Such modeling can also determine the potential exposure to zooplankton, and the impacts of oil spills with and without the use of dispersants. This paper reported on fluorescein dye studies that were conducted off Sand Diego, California to evaluate the ability of transport models to hindcast movement and dispersion of dye using data such as surface currents calculated from high-frequency radar; near surface currents from drifter measurements drogued at several depths; dye concentrations measured by fluorescence; spreading and dye intensity measurements based on aerial photography; and, water density profiles from conductivity-temperature-depth (CTD) casts. This paper presented modeling issues that remain to be addressed, such as the need to resolve small-scale transport processes in order to evaluate effects on water column biota. Since these processes determining current velocities are complex, it is not feasible to include most of the complexities at appropriately small scales in oil spill modeling applications. The difficulty in predicting currents that transport oil components and organisms with a hydrodynamic model application that does not include temporal details in the forcing function was also discussed. This paper demonstrated that the SIMAP spill trajectory model, using the drifter velocities as current input, successfully reproduced trajectories of the dye. The effect of wind drift transporting the surface material faster than the subsurface materials was identified as a spreading mechanism. Therefore, subtraction of the wind drift from the shallower drifter velocities, and inclusion of wind drift in SIMAP would allow those velocities to be used for depths other than those tracked by the drifters. 57 refs., 8 tabs., 17 figs.

  2. Estimating natal dispersal movement rates of female European ducks with multistate modeling

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    Blums, P.; Nichols, J.D.; Hines, J.E.; Lindberg, M.S.; Mednis, A.

    2003-01-01

    1. We used up to 34 years of capture-recapture data from about 22,100 new releases of day-old female ducklings and multistate modelling to test predictions about the influence of environmental, habitat and management factors on natal dispersal probability of three species of ducks within the Engure Marsh, Latvia. 2. The mean natal dispersal distances were very similar (c . 0?6-0?7 km) for all three species and were on average 2?7 times greater than breeding dispersal distances recorded within the same study system. 3. We were unable to confirm the kinship hypothesis and found no evidence that young first-nesting females nested closer to their relatives (either mother or sister) than to the natal nest. 4. Young female northern shovelers, like adults, moved from small islands to the large island when water level was high and vice versa when water level was low before the construction of elevated small islands. Movement probabilities between the two strata were much higher for young shovelers than adults, suggesting that young birds had not yet developed strong fidelity to the natal site. Movements of young female tufted ducks, unlike those of shovelers, were not dependent on water level fluctuations and reflected substantial flexibility in choice of first nesting sites. 5. Data for young birds supported our earlier conclusion that common pochard nesting habitats in black-headed gull colonies were saturated during the entire study period. Young females, like the two adult age groups, moved into and out of colonies with similar probability. Fidelity probability of female pochards to each stratum increased with age, being the lowest (0?62) for young (DK) females, intermediate (0?78) for yearlings (SY) and the highest (0?84) for adult (ASY) females. 6. Young female tufted ducks, like adults, showed higher probabilities of moving from islands to emergent marshes when water levels were higher both before and after habitat management. The relationship between the spring

  3. Seed dispersal and movement patterns in two species of Ceratogymna hornbills in a West African tropical lowland forest.

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    Holbrook, Kimberly M; Smith, Thomas B

    2000-10-01

    We studied two species of Ceratogymna hornbills, the black-casqued hornbill, C. atrata, and the white-thighed hornbill, C. cylindricus, in the tropical forests of Cameroon, to understand their movement patterns and evaluate their effectiveness as seed dispersers. To estimate hornbill contribution to a particular tree species' seed shadow we combined data from movements, determined by radio-tracking, with data from seed passage trials. For 13 individuals tracked over 12 months, home range varied between 925 and 4,472 ha, a much larger area than reported for other African avian frugivores. Seed passage times ranged from 51 to 765 min, with C. atrata showing longer passage times than C. cylindricus, and larger seeds having longer gut retention times than smaller seeds. Combining these data, we estimated that seed shadows were extensive for the eight tree species examined, with approximately 80% of seeds moved more than 500 m from the parent plant. Maximum estimated dispersal distances for larger seeds were 6,919 and 3,558 m for C. atrata and C. cylindricus, respectively. The extent of hornbill seed shadows suggests that their influence in determining forest structure will likely increase as other larger mammalian dispersers are exterminated.

  4. Water movement and fate of nitrogen during drip dispersal of wastewater effluent into a semi-arid landscape.

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    Siegrist, Robert L; Parzen, Rebecca; Tomaras, Jill; Lowe, Kathryn S

    2014-04-01

    Drip dispersal of partially treated wastewater was investigated as an approach for onsite water reclamation and beneficial reuse of water and nutrients in a semi-arid climate. At the Mines Park Test Site in Golden, Colorado, a drip dispersal system (DDS) was installed at 20- to 30-cm depth in an Ascalon sandy loam soil profile. Two zones with the same layout were established to enable study of two different hydraulic loading rates. Zones 1 and 2 each had one half of the landscape surface with native vegetation and the other with Kentucky bluegrass sod. After startup activities, domestic septic tank effluent was dispersed five times a day at footprint loading rates of 5 L/m(2)/d for Zone 1 and 10 L/m(2)/d for Zone 2. Over a two-year period, monitoring included the frequency and volume of effluent dispersed and its absorption by the landscape. After the first year of operation in October a (15)N tracer test was completed in the sodded portion of Zone 1 and samples of vegetation and soil materials were collected and analyzed for water content, pH, nitrogen, (15)N, and bacteria. Research revealed that both zones were capable of absorbing the effluent water applied at 5 or 10 L/m(2)/d. Effluent water dispersed from an emitter infiltrates at the emitter and along the drip tubing and water movement is influenced by hydrologic conditions. Based on precipitation and evapotranspiration at the Test Site, only a portion of the effluent water dispersed migrated downward in the soil (approx. 34% or 64% for Zone 1 or 2, respectively). Sampling within Zone 1 revealed water filled porosities were high throughout the soil profile (>85%) and water content was most elevated along the drip tubing (17-22% dry wt.), which is also where soil pH was most depressed (pH 4.5) due to nitrification reactions. NH4(+) and NO3(-) retention occurred near the dispersal location for several days and approximately 51% of the N applied was estimated to be removed by plant uptake and denitrification

  5. The influence of insecticide exposure and environmental stimuli on the movement behaviour and dispersal of a freshwater isopod.

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    Augusiak, Jacqueline; Van den Brink, Paul J

    2016-09-01

    Behaviour links physiological function with ecological processes and can be very sensitive towards environmental stimuli and chemical exposure. As such, behavioural indicators of toxicity are well suited for assessing impacts of pesticides at sublethal concentrations found in the environment. Recent developments in video-tracking technologies offer the possibility of quantifying behavioural patterns, particularly locomotion, which in general has not been studied and understood very well for aquatic macroinvertebrates to date. In this study, we aim to determine the potential effects of exposure to two neurotoxic pesticides with different modes of action at different concentrations (chlorpyrifos and imidacloprid) on the locomotion behaviour of the water louse Asellus aquaticus. We compare the effects of the different exposure regimes on the behaviour of Asellus with the effects that the presence of food and shelter exhibit to estimate the ecological relevance of behavioural changes. We found that sublethal pesticide exposure reduced dispersal distances compared to controls, whereby exposure to chlorpyrifos affected not only animal activity but also step lengths while imidacloprid only slightly affected step lengths. The presence of natural cues such as food or shelter induced only minor changes in behaviour, which hardly translated to changes in dispersal potential. These findings illustrate that behaviour can serve as a sensitive endpoint in toxicity assessments. However, under natural conditions, depending on the exposure concentration, the actual impacts might be outweighed by environmental conditions that an organism is subjected to. It is, therefore, of importance that the assessment of toxicity on behaviour is done under relevant environmental conditions.

  6. Shaken, Not Stirred: How Tidal Advection and Dispersion Mechanisms Rather Than Turbulent Mixing Impact the Movement and Fate of Aquatic Constituents and Fish in the California Central Valley

    Science.gov (United States)

    Sridharan, V. K.; Fong, D.; Monismith, S. G.; Jackson, D.; Russel, P.; Pope, A.; Danner, E.; Lindley, S. T.

    2016-12-01

    River deltas worldwide - home to nearly a billion people, thousands of species of flora and fauna, and economies worth trillions of dollars - have experienced massive ecosystem decline caused by urbanization, pollution, and water withdrawals. Habitat restoration in these systems is imperative not only for preserving endangered biomes, but also in sustaining human demand for freshwater and long term commercial viability. The sustainable management of heavily engineered, multi-use, branched tidal estuaries such as the Sacramento-San Joaquin Delta (henceforth, the Delta) requires utilizing physical transport and mixing process models. These inform us about the movement and fate of water quality constituents and aquatic organisms. This study identifies and quantifies the effects of various hydrodynamic mechanisms in the Delta across multiple spatio-temporal scales. A particle tracking model with accurate channel junction physics and an agent based model with realistic biological hypotheses of fish behavior were developed to study the movement and fate of tracers (surrogates for water quality constituents) and fish in the Delta. Simulations performed with these models were used to (1) determine the transport pathways through the Delta, (2) quantify the magnitude of transport and mixing processes along those pathways, and (3) describe the effects of physical stressors on fates of juvenile salmon. The Delta is largely dominated by large spatial scale advection by river flows, tidal pumping, and significantly increased dispersion through chaos due to the interaction of tidal flows with channel junctions. The movement and fate of simulated tracers and juvenile salmon are governed largely by the water diversion and pumping operations, transport pathways and chaotic tidal mixing mechanisms along those pathways. There is also a significant effect of predation on fish. These transport pathway and mechanistic dependencies indicate that restoration efforts which are harmonious

  7. Genetic Evidence of Contemporary Dispersal of the Intermediate Snail Host of Schistosoma japonicum: Movement of an NTD Host Is Facilitated by Land Use and Landscape Connectivity.

    Science.gov (United States)

    Head, Jennifer R; Chang, Howard; Li, Qunna; Hoover, Christopher M; Wilke, Thomas; Clewing, Catharina; Carlton, Elizabeth J; Liang, Song; Lu, Ding; Zhong, Bo; Remais, Justin V

    2016-12-01

    While the dispersal of hosts and vectors-through active or passive movement-is known to facilitate the spread and re-emergence of certain infectious diseases, little is known about the movement ecology of Oncomelania spp., intermediate snail host of the parasite Schistosoma japonicum, and its consequences for the spread of schistosomiasis in East and Southeast Asia. In China, despite intense control programs aimed at preventing schistosomiasis transmission, there is evidence in recent years of re-emergence and persistence of infection in some areas, as well as an increase in the spatial extent of the snail host. A quantitative understanding of the dispersal characteristics of the intermediate host can provide new insights into the spatial dynamics of transmission, and can assist public health officials in limiting the geographic spread of infection. Oncomelania hupensis robertsoni snails (n = 833) were sampled from 29 sites in Sichuan, China, genotyped, and analyzed using Bayesian assignment to estimate the rate of recent snail migration across sites. Landscape connectivity between each site pair was estimated using the geographic distance distributions derived from nine environmental models: Euclidean, topography, incline, wetness, land use, watershed, stream use, streams and channels, and stream velocity. Among sites, 14.4% to 32.8% of sampled snails were identified as recent migrants, with 20 sites comprising >20% migrants. Migration rates were generally low between sites, but at 8 sites, over 10% of the overall host population originated from one proximal site. Greater landscape connectivity was significantly associated with increased odds of migration, with the minimum path distance (as opposed to median or first quartile) emerging as the strongest predictor across all environmental models. Models accounting for land use explained the largest proportion of the variance in migration rates between sites. A greater number of irrigation channels leading into a

  8. Genetic Evidence of Contemporary Dispersal of the Intermediate Snail Host of Schistosoma japonicum: Movement of an NTD Host Is Facilitated by Land Use and Landscape Connectivity.

    Directory of Open Access Journals (Sweden)

    Jennifer R Head

    2016-12-01

    Full Text Available While the dispersal of hosts and vectors-through active or passive movement-is known to facilitate the spread and re-emergence of certain infectious diseases, little is known about the movement ecology of Oncomelania spp., intermediate snail host of the parasite Schistosoma japonicum, and its consequences for the spread of schistosomiasis in East and Southeast Asia. In China, despite intense control programs aimed at preventing schistosomiasis transmission, there is evidence in recent years of re-emergence and persistence of infection in some areas, as well as an increase in the spatial extent of the snail host. A quantitative understanding of the dispersal characteristics of the intermediate host can provide new insights into the spatial dynamics of transmission, and can assist public health officials in limiting the geographic spread of infection.Oncomelania hupensis robertsoni snails (n = 833 were sampled from 29 sites in Sichuan, China, genotyped, and analyzed using Bayesian assignment to estimate the rate of recent snail migration across sites. Landscape connectivity between each site pair was estimated using the geographic distance distributions derived from nine environmental models: Euclidean, topography, incline, wetness, land use, watershed, stream use, streams and channels, and stream velocity. Among sites, 14.4% to 32.8% of sampled snails were identified as recent migrants, with 20 sites comprising >20% migrants. Migration rates were generally low between sites, but at 8 sites, over 10% of the overall host population originated from one proximal site. Greater landscape connectivity was significantly associated with increased odds of migration, with the minimum path distance (as opposed to median or first quartile emerging as the strongest predictor across all environmental models. Models accounting for land use explained the largest proportion of the variance in migration rates between sites. A greater number of irrigation channels

  9. Inbreeding avoidance, patch isolation and matrix permeability influence dispersal and settlement choices by male agile antechinus in a fragmented landscape.

    Science.gov (United States)

    Banks, Sam C; Lindenmayer, David B

    2014-03-01

    Animal dispersal is highly non-random and has important implications for the dynamics of populations in fragmented habitat. We identified interpatch dispersal events from genetic tagging, parentage analyses and assignment tests and modelled the factors associated with apparent emigration and post-dispersal settlement choices by individual male agile antechinus (Antechinus agilis, a marsupial carnivore of south-east Australian forests). Emigration decisions were best modelled with on data patch isolation and inbreeding risk. The choice of dispersal destination by males was influenced by inbreeding risk, female abundance, patch size, patch quality and matrix permeability (variation in land cover). Males were less likely to settle in patches without highly unrelated females. Our findings highlight the importance of individual-level dispersal data for understanding how multiple processes drive non-randomness in dispersal in modified landscapes. Fragmented landscapes present novel environmental, demographic and genetic contexts in which dispersal decisions are made, so the major factors affecting dispersal decisions in fragmented habitat may differ considerably from unfragmented landscapes. We show that the spatial scale of genetic neighbourhoods can be large in fragmented habitat, such that dispersing males can potentially settle in the presence of genetically similar females after moving considerable distances, thereby necessitating both a choice to emigrate and a choice of where to settle to avoid inbreeding. © 2013 The Authors. Journal of Animal Ecology © 2013 British Ecological Society.

  10. Bowel Movement

    Science.gov (United States)

    A bowel movement is the last stop in the movement of food through your digestive tract. Your stool passes out of ... what you eat and drink. Sometimes a bowel movement isn't normal. Diarrhea happens when stool passes ...

  11. Applying network theory to animal movements to identify properties of landscape space use.

    Science.gov (United States)

    Bastille-Rousseau, Guillaume; Douglas-Hamilton, Iain; Blake, Stephen; Northrup, Joseph M; Wittemyer, George

    2018-04-01

    Network (graph) theory is a popular analytical framework to characterize the structure and dynamics among discrete objects and is particularly effective at identifying critical hubs and patterns of connectivity. The identification of such attributes is a fundamental objective of animal movement research, yet network theory has rarely been applied directly to animal relocation data. We develop an approach that allows the analysis of movement data using network theory by defining occupied pixels as nodes and connection among these pixels as edges. We first quantify node-level (local) metrics and graph-level (system) metrics on simulated movement trajectories to assess the ability of these metrics to pull out known properties in movement paths. We then apply our framework to empirical data from African elephants (Loxodonta africana), giant Galapagos tortoises (Chelonoidis spp.), and mule deer (Odocoileous hemionus). Our results indicate that certain node-level metrics, namely degree, weight, and betweenness, perform well in capturing local patterns of space use, such as the definition of core areas and paths used for inter-patch movement. These metrics were generally applicable across data sets, indicating their robustness to assumptions structuring analysis or strategies of movement. Other metrics capture local patterns effectively, but were sensitive to specified graph properties, indicating case specific applications. Our analysis indicates that graph-level metrics are unlikely to outperform other approaches for the categorization of general movement strategies (central place foraging, migration, nomadism). By identifying critical nodes, our approach provides a robust quantitative framework to identify local properties of space use that can be used to evaluate the effect of the loss of specific nodes on range wide connectivity. Our network approach is intuitive, and can be implemented across imperfectly sampled or large-scale data sets efficiently, providing a

  12. Movement - uncoordinated

    Science.gov (United States)

    ... Loss of coordination; Coordination impairment; Ataxia; Clumsiness; Uncoordinated movement ... Smooth graceful movement requires a balance between different muscle groups. A part of the brain called the cerebellum manages this balance.

  13. Slope movements

    International Nuclear Information System (INIS)

    Wagner, P.

    2009-01-01

    On this poster some reasons of slope movements on the territory of the Slovak Republic are presented. Slope movements induced deterioration of land and forests, endangering of towns villages, and communications as well as hydro-engineering structures. Methods of preventing and stabilisation of slope movements are presented.

  14. Hydrodynamic disperser

    Energy Technology Data Exchange (ETDEWEB)

    Bulatov, A.I.; Chernov, V.S.; Prokopov, L.I.; Proselkov, Yu.M.; Tikhonov, Yu.P.

    1980-01-15

    A hydrodynamic disperser is suggested which contains a housing, slit nozzles installed on a circular base arranged opposite from each other, resonators secured opposite the nozzle and outlet sleeve. In order to improve the effectiveness of dispersion by throttling the flow, each resonator is made in the form of a crimped plate with crimpings that decrease in height in a direction towards the nozzle.

  15. Dispersion Forces

    CERN Document Server

    Buhmann, Stefan Yoshi

    2012-01-01

    In this book, a modern unified theory of dispersion forces on atoms and bodies is presented which covers a broad range of advanced aspects and scenarios. Macroscopic quantum electrodynamics is shown to provide a powerful framework for dispersion forces which allows for discussing general properties like their non-additivity and the relation between microscopic and macroscopic interactions. It is demonstrated how the general results can be used to obtain dispersion forces on atoms in the presence of bodies of various shapes and materials. Starting with a brief recapitulation of volume I, this volume II deals especially with bodies of irregular shapes, universal scaling laws, dynamical forces on excited atoms, enhanced forces in cavity quantum electrodynamics, non-equilibrium forces in thermal environments and quantum friction. The book gives both the specialist and those new to the field a thorough overview over recent results in the field. It provides a toolbox for studying dispersion forces in various contex...

  16. Movement - uncontrolled or slow

    Science.gov (United States)

    Dystonia; Involuntary slow and twisting movements; Choreoathetosis; Leg and arm movements - uncontrollable; Arm and leg movements - uncontrollable; Slow involuntary movements of large muscle groups; Athetoid movements

  17. Chemical dispersants

    NARCIS (Netherlands)

    Rahsepar, Shokouhalsadat; Smit, Martijn P.J.; Murk, Albertinka J.; Rijnaarts, Huub H.M.; Langenhoff, Alette A.M.

    2016-01-01

    Chemical dispersants were used in response to the Deepwater Horizon oil spill in the Gulf of Mexico, both at the sea surface and the wellhead. Their effect on oil biodegradation is unclear, as studies showed both inhibition and enhancement. This study addresses the effect of Corexit on oil

  18. Protest movements

    International Nuclear Information System (INIS)

    Rucht, D.

    1989-01-01

    The author describes the development of protest movements in postwar Germay and outlines two essential overlapping 'flow cycles'. The first of these was characterised by the restaurative postwar years. It culminated and ended in the students' revolt. This revolt is at the same time the start of a second cycle of protest which encompasses all subsequent individual movement and is initated by an economic, political and sociocultural procrastination of modernisation. This cycle culminates in the late 70s and early 80s and clearly lost momentum over the last few years. The follwoing phases and themes are described profoundly: against restauration and armament in the 1950; the revolutionary impatience of the students' movement, politisation of everyday life by the womens' movement and citizens' action groups, antinuclear- and ecological movement, differentiation and stabilisation of the movement in the 70s and 80s; break-up and continuity in the German protest behaviour. The paper contains a detailed chronicle of protest activities since 1945. (orig.) [de

  19. Dispersion and current measurements

    International Nuclear Information System (INIS)

    Boelskifte, S.

    1986-04-01

    A model for the simulation of particle movements in water should incorporate the mutual distance dependent correlation. As long as reliable data are given accessible a model can be created of the dispersion in a given area from a statistical description of turbulence. Current measurements have been performed in an area north of the Swedish nuclear power plant Barsebaeck, and statistical time series analysis have made it possible to estimate multivariate autoregressive moving-average (ARMA) models for these data using the Box-Jenkins method. The correlation structure for the area has been investigated in detail. Transport and dispersion models for the marine environment are used in estimating doses to the population from the aquatic food chain. Some of these models are described with special emphasis on the time and length scales they cover. Furthermore, to illustrate the background of the simulation model, short introductuions are given to health physics, time series analysis, and turbulence theory. Analysis of the simulation model shows the relative importance of the different parameters. The model can be expanded to conditional simulation, where the current measurements are used directly to simulate the movement of one of the particles. Results from the model are also compared to results from a sampling of bioindicators (Fucus vesiculosus) along the Danish coast. The reliability of bioindicators in this kind of experiment is discussed. (author)

  20. Plant water stress effects on the net dispersal rate of the insect vector Homalodisca vitripennis (Germar) (Hemiptera: Cicadellidae) and movement of its egg parasitoid, Gonatocerus ashmeadi Girault (Hymenoptera: Mymaridae)

    Science.gov (United States)

    Homalodisca vitripennis, one of the main vectors of Xylella fastidiosa, is associated with citrus plantings in California, USA. Infested citrus orchards act as a source of vectors to adjacent vineyards where X. fastidiosa causes Pierce’s disease (PD). An analysis of the pattern and rate of movement ...

  1. Behavioral tradeoffs when dispersing across a patchy landscape.

    Science.gov (United States)

    Patrick A. Zollner; Steven L. Lima

    2005-01-01

    A better understanding of the behavior of dispersing animals will assist in determining the factors that limit their success and ultimately help improve the way dispersal is incorporated into population models. To that end, we used a simulation model to investigate three questions about behavioral tradeoffs that dispersing animals might face: (i) speed of movement...

  2. Striking movements

    DEFF Research Database (Denmark)

    Dahl, Sofia

    2011-01-01

    Like all music performance, percussion playing requires high control over timing and sound properties. Specific to percussionists, however, is the need to adjust the movement to different instruments with varying physical properties and tactile feedback to the player. Furthermore, the well defined...... note onsets and short interaction times between player and instrument do not allow for much adjustment once a stroke is initiated. The paper surveys research that shows a close relationship between movement and sound production, and how playing conditions such as tempo and the rebound after impact...

  3. Movement disorders

    International Nuclear Information System (INIS)

    Leenders, K.L.

    1986-01-01

    This thesis describes the measurement of brain-tissue functions in patients with movement disorders using positron emission tomography (PET). This scanning technique is a method for direct in vivo quantitation of the regional tissue content of positron emitting radionuclides in brain (or other organs) in an essentially non-invasive way. Ch. 2 outlines some general features of PET and describes the scanner which has been used for the studies in this thesis. Also the tracer methodology, as applied to data investigations of movement disorders, are discussed. Ch. 3 contains the results of the PET investigations which were performed in the study of movement disorders. The results are presented in the form of 12 papers. The main goals of these studies were the understanding of the pathophysiology of Parkinson's disease, Huntington's chorea, Steele-Richardson-Olzewski syndrome and special case reports. Ch. 4 summarizes the results of these publications and Ch. 5 concludes the main part of this thesis with a general discussion of movement disorders in relation to PET investigations. 697 refs.; 60 figs.; 31 tabs

  4. Psychodynamic Movement

    DEFF Research Database (Denmark)

    Pedersen, Inge Nygaard

    2002-01-01

    This chapter/article describes the historical development of the disciplin Psychodynamic Movement. The importance of this disciplin for self-experience and for training in developing a therapist identy for the music therapy students are emphasized. Prototypeexercises developed and simplified...

  5. Mixed Movements

    DEFF Research Database (Denmark)

    Brabrand, Helle

    2010-01-01

    levels than those related to building, and this exploration is a special challenge and competence implicit artistic development work. The project Mixed Movements generates drawing-material, not primary as representation, but as a performance-based media, making the body being-in-the-media felt and appear...... as possible operational moves....

  6. Dispersion strengthening

    International Nuclear Information System (INIS)

    Scattergood, R.O.; Das, E.S.P.

    1976-01-01

    Using digital computer-based methods, models for dispersion strengthening can now be developed which take into account many of the important effects that have been neglected in the past. In particular, the self interaction of a dislocation can be treated, and a computer simulation method was developed to determine the flow stress of a random distribution of circular, impenetrable obstacles, taking into account all such interactions. The flow stress values depended on the obstacle sizes and spacings, over and above the usual 1/L dependence where L is the average obstacle spacing. From an analysis of the results, it was found that the main effects of the self interactions can be captured in a line tension analogue in which the obstacles appear to be penetrable

  7. Dispersal Ecology Informs Design of Large-Scale Wildlife Corridors.

    Science.gov (United States)

    Benz, Robin A; Boyce, Mark S; Thurfjell, Henrik; Paton, Dale G; Musiani, Marco; Dormann, Carsten F; Ciuti, Simone

    Landscape connectivity describes how the movement of animals relates to landscape structure. The way in which movement among populations is affected by environmental conditions is important for predicting the effects of habitat fragmentation, and for defining conservation corridors. One approach has been to map resistance surfaces to characterize how environmental variables affect animal movement, and to use these surfaces to model connectivity. However, current connectivity modelling typically uses information on species location or habitat preference rather than movement, which unfortunately may not capture dispersal limitations. Here we emphasize the importance of implementing dispersal ecology into landscape connectivity, i.e., observing patterns of habitat selection by dispersers during different phases of new areas' colonization to infer habitat connectivity. Disperser animals undertake a complex sequence of movements concatenated over time and strictly dependent on species ecology. Using satellite telemetry, we investigated the movement ecology of 54 young male elk Cervus elaphus, which commonly disperse, to design a corridor network across the Northern Rocky Mountains. Winter residency period is often followed by a spring-summer movement phase, when young elk migrate with mothers' groups to summering areas, and by a further dispersal bout performed alone to a novel summer area. After another summer residency phase, dispersers usually undertake a final autumnal movement to reach novel wintering areas. We used resource selection functions to identify winter and summer habitats selected by elk during residency phases. We then extracted movements undertaken during spring to move from winter to summer areas, and during autumn to move from summer to winter areas, and modelled them using step selection functions. We built friction surfaces, merged the different movement phases, and eventually mapped least-cost corridors. We showed an application of this tool by

  8. Computational movement analysis

    CERN Document Server

    Laube, Patrick

    2014-01-01

    This SpringerBrief discusses the characteristics of spatiotemporal movement data, including uncertainty and scale. It investigates three core aspects of Computational Movement Analysis: Conceptual modeling of movement and movement spaces, spatiotemporal analysis methods aiming at a better understanding of movement processes (with a focus on data mining for movement patterns), and using decentralized spatial computing methods in movement analysis. The author presents Computational Movement Analysis as an interdisciplinary umbrella for analyzing movement processes with methods from a range of fi

  9. Hydrodynamic dispersion

    International Nuclear Information System (INIS)

    Pryce, M.H.L.

    1985-01-01

    A dominant mechanism contributing to hydrodynamic dispersion in fluid flow through rocks is variation of travel speeds within the channels carrying the fluid, whether these be interstices between grains, in granular rocks, or cracks in fractured crystalline rocks. The complex interconnections of the channels ensure a mixing of those parts of the fluid which travel more slowly and those which travel faster. On a macroscopic scale this can be treated statistically in terms of the distribution of times taken by a particle of fluid to move from one surface of constant hydraulic potential to another, lower, potential. The distributions in the individual channels are such that very long travel times make a very important contribution. Indeed, while the mean travel time is related to distance by a well-defined transport speed, the mean square is effectively infinite. This results in an asymmetrical plume which differs markedly from a gaussian shape. The distribution of microscopic travel times is related to the distribution of apertures in the interstices, or in the microcracks, which in turn are affected in a complex way by the stresses acting on the rock matrix

  10. The movement ecology of seagrasses.

    Science.gov (United States)

    McMahon, Kathryn; van Dijk, Kor-Jent; Ruiz-Montoya, Leonardo; Kendrick, Gary A; Krauss, Siegfried L; Waycott, Michelle; Verduin, Jennifer; Lowe, Ryan; Statton, John; Brown, Eloise; Duarte, Carlos

    2014-11-22

    A movement ecology framework is applied to enhance our understanding of the causes, mechanisms and consequences of movement in seagrasses: marine, clonal, flowering plants. Four life-history stages of seagrasses can move: pollen, sexual propagules, vegetative fragments and the spread of individuals through clonal growth. Movement occurs on the water surface, in the water column, on or in the sediment, via animal vectors and through spreading clones. A capacity for long-distance dispersal and demographic connectivity over multiple timeframes is the novel feature of the movement ecology of seagrasses with significant evolutionary and ecological consequences. The space-time movement footprint of different life-history stages varies. For example, the distance moved by reproductive propagules and vegetative expansion via clonal growth is similar, but the timescales range exponentially, from hours to months or centuries to millennia, respectively. Consequently, environmental factors and key traits that interact to influence movement also operate on vastly different spatial and temporal scales. Six key future research areas have been identified.

  11. Dispersal and migration

    Directory of Open Access Journals (Sweden)

    Schwarz, C.

    2004-06-01

    Full Text Available Ringing of birds unveiled many aspects of avian migration and dispersal movements. However, there is even much more to be explored by the use of ringing and other marks. Dispersal is crucial in understanding the initial phase of migration in migrating birds as it is to understand patterns and processes of distribution and gene flow. So far, the analysis of migration was largely based on analysing spatial and temporal patters of recoveries of ringed birds. However, there are considerable biases and pitfalls in using recoveries due to spatial and temporal variation in reporting probabilities. Novel methods are required for future studies separating the confounding effects of spatial and temporal heterogeneity of recovery data and heterogeneity of the landscape as well. These novel approaches should aim a more intensive and novel use of the existing recovery data by taking advantage of, for instance, dynamic and multistate modeling, should elaborate schemes for future studies, and should also include other marks that allow a more rapid data collection, like telemetry, geolocation and global positioning systems, and chemical and molecular markers. The latter appear to be very useful in the delineating origin of birds and connectivity between breeding and non–breeding grounds. Many studies of migration are purely descriptive. However, King and Brooks (King & Brooks, 2004 examine if movement patterns of dolphins change after the introduction of a gillnet ban. Bayesian methods are an interesting approach to this problem as they provide a meaningful measure of the probability that such a change occurred rather than simple yes/no response that is often the result of classical statistical methods. However, the key difficulty of a general implementation of Bayesian methods is the complexity of the modelling —there is no general userfriendly package that is easily accessible to most scientists. Drake and Alisauskas (Drake & Alisauskas, 2004 examine the

  12. Strategic and tactical use of movement information in pest management

    Science.gov (United States)

    Knipling, E. F.

    1979-01-01

    Several insect movement problems are discussed. Much more information is needed to make a better appraisal of the practical significance of the insect dispersal problem. Data on the time, rate, and extent of movement of insects are provided. Better techniques for measuring insect movement are developed. A better understanding of the importance of insect movement in the development and implementation of more effective and ecologically acceptable pest management strategies and tactics was proved.

  13. Seed dispersal in fens

    NARCIS (Netherlands)

    Middleton, Beth; van Diggelen, Rudy; Jensen, Kai

    Question: How does seed dispersal reduce fen isolation and contribute to biodiversity? Location: European and North American fens. Methods: This paper reviews the literature on seed dispersal to fens. Results: Landscape fragmentation may reduce dispersal opportunities thereby isolating fens and

  14. Seed-dispersal distributions by trumpeter hornbills in fragmented landscapes

    Science.gov (United States)

    Lenz, Johanna; Fiedler, Wolfgang; Caprano, Tanja; Friedrichs, Wolfgang; Gaese, Bernhard H.; Wikelski, Martin; Böhning-Gaese, Katrin

    2011-01-01

    Frugivorous birds provide important ecosystem services by transporting seeds of fleshy fruited plants. It has been assumed that seed-dispersal kernels generated by these animals are generally leptokurtic, resulting in little dispersal among habitat fragments. However, little is known about the seed-dispersal distribution generated by large frugivorous birds in fragmented landscapes. We investigated movement and seed-dispersal patterns of trumpeter hornbills (Bycanistes bucinator) in a fragmented landscape in South Africa. Novel GPS loggers provide high-quality location data without bias against recording long-distance movements. We found a very weakly bimodal seed-dispersal distribution with potential dispersal distances up to 14.5 km. Within forest, the seed-dispersal distribution was unimodal with an expected dispersal distance of 86 m. In the fragmented agricultural landscape, the distribution was strongly bimodal with peaks at 18 and 512 m. Our results demonstrate that seed-dispersal distributions differed when birds moved in different habitat types. Seed-dispersal distances in fragmented landscapes show that transport among habitat patches is more frequent than previously assumed, allowing plants to disperse among habitat patches and to track the changing climatic conditions. PMID:21177686

  15. Functional Movement Disorder

    Science.gov (United States)

    ... Publications Patient Organizations International Parkinson and Movement Disorder Society National Institute of Mental Health (NIMH) See all related organizations Publications Order NINDS Publications Definition Psychogenic movement is an unwanted muscle movement such ...

  16. Large-scale movements in European badgers: has the tail of the movement kernel been underestimated?

    Science.gov (United States)

    Byrne, Andrew W; Quinn, John L; O'Keeffe, James J; Green, Stuart; Sleeman, D Paddy; Martin, S Wayne; Davenport, John

    2014-07-01

    Characterizing patterns of animal movement is a major aim in population ecology, and yet doing so at an appropriate spatial scale remains a major challenge. Estimating the frequency and distances of movements is of particular importance when species are implicated in the transmission of zoonotic diseases. European badgers (Meles meles) are classically viewed as exhibiting limited dispersal, and yet their movements bring them into conflict with farmers due to their potential to spread bovine tuberculosis in parts of their range. Considerable uncertainty surrounds the movement potential of badgers, and this may be related to the spatial scale of previous empirical studies. We conducted a large-scale mark-recapture study (755 km(2); 2008-2012; 1935 capture events; 963 badgers) to investigate movement patterns in badgers, and undertook a comparative meta-analysis using published data from 15 European populations. The dispersal movement (>1 km) kernel followed an inverse power-law function, with a substantial 'tail' indicating the occurrence of rare long-distance dispersal attempts during the study period. The mean recorded distance from this distribution was 2.6 km, the 95 percentile was 7.3 km and the longest recorded was 22.1 km. Dispersal frequency distributions were significantly different between genders; males dispersed more frequently than females, but females made proportionally more long-distance dispersal attempts than males. We used a subsampling approach to demonstrate that the appropriate minimum spatial scale to characterize badger movements in our study population was 80 km(2), substantially larger than many previous badger studies. Furthermore, the meta-analysis indicated a significant association between maximum movement distance and study area size, while controlling for population density. Maximum long-distance movements were often only recorded by chance beyond the boundaries of study areas. These findings suggest that the tail of the badger

  17. Internal dispersal of seeds by waterfowl: effect of seed size on gut passage time and germination patterns

    NARCIS (Netherlands)

    Figuerola, J.; Charalambidou, I.; Santamaria, L.; Green, A.J.

    2010-01-01

    Long distance dispersal may have important consequences for gene flow and community structure. The dispersal of many plants depends on transport by vertebrate seed dispersers. The shapes of seed shadows produced by vertebrates depend both on movement patterns of the dispersers and on the dynamics

  18. Clock synchronization and dispersion

    International Nuclear Information System (INIS)

    Giovannetti, Vittorio; Lloyd, Seth; Maccone, Lorenzo; Wong, Franco N C

    2002-01-01

    We present a method to defeat effects of dispersion of timing signals when synchronizing clocks. It is based on the recently proposed 'conveyor belt synchronization' scheme and on the quantum dispersion cancellation effect

  19. Dispersing powders in liquids

    CERN Document Server

    Nelson, RD

    1988-01-01

    This book provides powder technologists with laboratory procedures for selecting dispersing agents and preparing stable dispersions that can then be used in particle size characterization instruments. Its broader goal is to introduce industrial chemists and engineers to the phenomena, terminology, physical principles, and chemical considerations involved in preparing and handling dispersions on a commercial scale. The book introduces novices to: - industrial problems due to improper degree of dispersion; - the nomenclature used in describing particles; - the basic physica

  20. Theory of dispersive microlenses

    Science.gov (United States)

    Herman, B.; Gal, George

    1993-01-01

    A dispersive microlens is a miniature optical element which simultaneously focuses and disperses light. Arrays of dispersive mircolenses have potential applications in multicolor focal planes. They have a 100 percent optical fill factor and can focus light down to detectors of diffraction spot size, freeing up areas on the focal plane for on-chip analog signal processing. Use of dispersive microlenses allows inband color separation within a pixel and perfect scene registration. A dual-color separation has the potential for temperature discrimination. We discuss the design of dispersive microlenses and present sample results for efficient designs.

  1. Broadening our approaches to studying dispersal in raptors

    Science.gov (United States)

    Morrison, J.L.; Wood, P.B.

    2009-01-01

    Dispersal is a behavioral process having consequences for individual fitness and population dynamics. Recent advances in technology have spawned new theoretical examinations and empirical studies of the dispersal process in birds, providing opportunities for examining how this information may be applied to studies of the dispersal process in raptors. Many raptors are the focus of conservation efforts; thus, reliable data on all aspects of a species' population dynamics, including dispersal distances, movement rates, and mortality rates of dispersers, are required for population viability analyses that are increasingly used to inform management. Here, we address emerging issues and novel approaches used in the study of avian dispersal, and provide suggestions to consider when developing and implementing studies of dispersal in raptors. Clarifying study objectives is essential for selection of an appropriate methodology and sample size needed to obtain accurate estimates of movement distances and rates. Identifying an appropriate study-area size will allow investigators to avoid underestimating population connectivity and important population parameters. Because nomadic individuals of some species use temporary settling areas or home ranges before breeding, identification of these areas is critical for conservation efforts focusing on habitats other than breeding sites. Study designs for investigating raptor dispersal also should include analysis of environmental and social factors influencing dispersal, to improve our understanding of condition-dependent dispersal strategies. Finally, we propose a terminology for use in describing the variety of movements associated with dispersal behavior in raptors, and we suggest this terminology could be used consistently to facilitate comparisons among studies. ?? 2009 The Raptor Research Foundation, Inc.

  2. Juvenile dispersal in Calomys venustus (Muridae: Sigmodontinae)

    Science.gov (United States)

    Priotto, José; Steinmann, Andrea; Provensal, Cecilia; Polop, Jaime

    2004-05-01

    Both spacing behaviour and dispersal movement are viewed as hierarchical processes in which the effects may be expressed at spatial scale. This research was carried out to examine the hypothesis that the presence of parents promotes the dispersal of juveniles from their natal nest and their father or mother home-range, in Calomys venustus.The study was carried out in four 0.25 ha fences (two controls and two experimentals), in a natural pasture. This study had two periods: Father Removal (FR) (August and December 1997; year one) and Mother Removal (MR) (August 1998 and January 1999; year two). For the FR treatment fathers were removed after juveniles were born, but in the MR treatment mothers were removed after the juveniles were weaned. The effect of parents on the dispersal distance of juveniles was analysed with respect to their natal nest and their mother and father home-range. Dispersal distance from the nest of C. venustus was independent of either male or female parent. Juveniles were more dispersing in relation to the centre of activity of their mothers than to that of their fathers, and females were more dispersing than males. Female juveniles overlap their home-range with their parents less than male juveniles do. The differences observed between female and male juveniles would be related to their different sexual maturation times, as well as to the female territoriality.

  3. Modelling long-distance seed dispersal in heterogeneous landscapes.

    Energy Technology Data Exchange (ETDEWEB)

    Levey, Douglas, J.; Tewlsbury, Joshua, J.; Bolker, Benjamin, M.

    2008-01-01

    1. Long-distance seed dispersal is difficult to measure, yet key to understanding plant population dynamics and community composition. 2. We used a spatially explicit model to predict the distribution of seeds dispersed long distances by birds into habitat patches of different shapes. All patches were the same type of habitat and size, but varied in shape. They occurred in eight experimental landscapes, each with five patches of four different shapes, 150 m apart in a matrix of mature forest. The model was parameterized with smallscale movement data collected from field observations of birds. In a previous study we validated the model by testing its predictions against observed patterns of seed dispersal in real landscapes with the same types and spatial configuration of patches as in the model. 3. Here we apply the model more broadly, examining how patch shape influences the probability of seed deposition by birds into patches, how dispersal kernels (distributions of dispersal distances) vary with patch shape and starting location, and how movement of seeds between patches is affected by patch shape. 4. The model predicts that patches with corridors or other narrow extensions receive higher numbers of seeds than patches without corridors or extensions. This pattern is explained by edgefollowing behaviour of birds. Dispersal distances are generally shorter in heterogeneous landscapes (containing patchy habitat) than in homogeneous landscapes, suggesting that patches divert the movement of seed dispersers, ‘holding’ them long enough to increase the probability of seed defecation in the patches. Dispersal kernels for seeds in homogeneous landscapes were smooth, whereas those in heterogenous landscapes were irregular. In both cases, long-distance (> 150 m) dispersal was surprisingly common, usually comprising approximately 50% of all dispersal events. 5. Synthesis . Landscape heterogeneity has a large influence on patterns of long-distance seed dispersal. Our

  4. Stereotypic movement disorder

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/001548.htm Stereotypic movement disorder To use the sharing features on this page, please enable JavaScript. Stereotypic movement disorder is a condition in which a person makes ...

  5. Eye Movement Disorders

    Science.gov (United States)

    ... work properly. There are many kinds of eye movement disorders. Two common ones are Strabismus - a disorder ... in "crossed eyes" or "walleye." Nystagmus - fast, uncontrollable movements of the eyes, sometimes called "dancing eyes" Some ...

  6. Overview of Movement Disorders

    Science.gov (United States)

    ... of Delirium Additional Content Medical News Overview of Movement Disorders By Hector A. Gonzalez-Usigli, MD, Professor ... Neurology, HE UMAE Centro Médico Nacional de Occidente; Movement Disorders Clinic, Neurology at IMSS Alberto Espay, MD, ...

  7. Independence of Movement Preparation and Movement Initiation.

    Science.gov (United States)

    Haith, Adrian M; Pakpoor, Jina; Krakauer, John W

    2016-03-09

    Initiating a movement in response to a visual stimulus takes significantly longer than might be expected on the basis of neural transmission delays, but it is unclear why. In a visually guided reaching task, we forced human participants to move at lower-than-normal reaction times to test whether normal reaction times are strictly necessary for accurate movement. We found that participants were, in fact, capable of moving accurately ∼80 ms earlier than their reaction times would suggest. Reaction times thus include a seemingly unnecessary delay that accounts for approximately one-third of their duration. Close examination of participants' behavior in conventional reaction-time conditions revealed that they generated occasional, spontaneous errors in trials in which their reaction time was unusually short. The pattern of these errors could be well accounted for by a simple model in which the timing of movement initiation is independent of the timing of movement preparation. This independence provides an explanation for why reaction times are usually so sluggish: delaying the mean time of movement initiation relative to preparation reduces the risk that a movement will be initiated before it has been appropriately prepared. Our results suggest that preparation and initiation of movement are mechanistically independent and may have a distinct neural basis. The results also demonstrate that, even in strongly stimulus-driven tasks, presentation of a stimulus does not directly trigger a movement. Rather, the stimulus appears to trigger an internal decision whether to make a movement, reflecting a volitional rather than reactive mode of control. Copyright © 2016 the authors 0270-6474/16/363007-10$15.00/0.

  8. Movement and Space

    DEFF Research Database (Denmark)

    Riisgaard Hansen, Thomas; Eriksson, Eva; Lykke-Olesen, Andreas

    2005-01-01

    In this paper we explore the space in which movement based interaction takes place. We have in several projects explored how fixed and mobile cameras can be used in movement based interaction and will shortly describe these projects. Based on our experience with working with movement......-based interaction we will briefly introduce and discuss how learning, mapping and multi-user interaction are important when designing movement based interaction....

  9. Recent crustal movements

    Science.gov (United States)

    Maelzer, H.

    Calculation of temporal height changes for the determination of recent vertical crustal movements in northern, western, and southern Germany is described. Precise geodetic measurements and their analysis for the determination of recent crustal movements in north-eastern Iceland, western Venezuela, and central Peru are described. Determination of recent vertical crustal movements by leveling and gravity data; geodetic modeling of deformations and recent crustal movements; geodetic modeling of plate motions; and instrumental developments in geodetic measuring are discussed.

  10. Social movements and science

    DEFF Research Database (Denmark)

    Jamison, Andrew

    2006-01-01

    The article examines the role of social movements in the development of scientific knowledge. Interactions between social movements and science in broad, historical terms are discussed. The relations between the new social movements of the 1960s and 1970s and changes in the contemporary scientific...

  11. Juvenile Dispersal of Harpy Eagles (Harpia harpyja) in Ecuador

    OpenAIRE

    Urios, Vicente; Muñiz López, Ruth; Vidal-Mateo, Javier

    2017-01-01

    The movement ecology of Harpy Eagles (Harpia harpyja) is poorly known due to the difficulty observing this species. We studied the movements of two juvenile Harpy Eagles before and during dispersal using GPS satellite telemetry in the Reserva de Producción Faunística Cuyabeno, Ecuador. Both eagles were tagged at their respective nest tree. For each eagle, we calculated the daily distance moved and the distance from each recorded position to the nest. One eagle started dispersal during its 28t...

  12. Dispersal of forest insects

    Science.gov (United States)

    Mcmanus, M. L.

    1979-01-01

    Dispersal flights of selected species of forest insects which are associated with periodic outbreaks of pests that occur over large contiguous forested areas are discussed. Gypsy moths, spruce budworms, and forest tent caterpillars were studied for their massive migrations in forested areas. Results indicate that large dispersals into forested areas are due to the females, except in the case of the gypsy moth.

  13. Improved new generation dispersants

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    The use of dispersants to combat oil spills has attracted controversy over the years, and there has been a number of accusations of the chemicals involved doing more harm than good. A new study by the International Petroleum Industry Environmental Conservation Association discusses the positive and the negatives of dispersant use to be considered when drawing up spill contingency plans. (author)

  14. Seed dispersal in fens

    Science.gov (United States)

    Middleton, B.; Van Diggelen, R.; Jensen, K.

    2006-01-01

    Question: How does seed dispersal reduce fen isolation and contribute to biodiversity? Location: European and North American fens. Methods: This paper reviews the literature on seed dispersal to fens. Results: Landscape fragmentation may reduce dispersal opportunities thereby isolating fens and reducing genetic exchange. Species in fragmented wetlands may have lower reproductive success, which can lead to biodiversity loss. While fens may have always been relatively isolated from each other, they have become increasingly fragmented in modern times within agricultural and urban landscapes in both Europe and North America. Dispersal by water, animals and wind has been hampered by changes related to development in landscapes surrounding fens. Because the seeds of certain species are long-lived in the seed bank, frequent episodes of dispersal are not always necessary to maintain the biodiversity of fens. However, of particular concern to restoration is that some dominant species, such as the tussock sedge Carex stricta, may not disperse readily between fens. Conclusions: Knowledge of seed dispersal can be used to maintain and restore the biodiversity of fens in fragmented landscapes. Given that development has fragmented landscapes and that this situation is not likely to change, the dispersal of seeds might be enhanced by moving hay or cattle from fens to damaged sites, or by reestablishing lost hydrological connections. ?? IAVS; Opulus Press.

  15. Dispersal and metapopulation stability

    Directory of Open Access Journals (Sweden)

    Shaopeng Wang

    2015-10-01

    Full Text Available Metapopulation dynamics are jointly regulated by local and spatial factors. These factors may affect the dynamics of local populations and of the entire metapopulation differently. Previous studies have shown that dispersal can stabilize local populations; however, as dispersal also tends to increase spatial synchrony, its net effect on metapopulation stability has been controversial. Here we present a simple metapopulation model to study how dispersal, in interaction with other spatial and local processes, affects the temporal variability of metapopulations in a stochastic environment. Our results show that in homogeneous metapopulations, the local stabilizing and spatial synchronizing effects of dispersal cancel each other out, such that dispersal has no effect on metapopulation variability. This result is robust to moderate heterogeneities in local and spatial parameters. When local and spatial dynamics exhibit high heterogeneities, however, dispersal can either stabilize or destabilize metapopulation dynamics through various mechanisms. Our findings have important theoretical and practical implications. We show that dispersal functions as a form of spatial intraspecific mutualism in metapopulation dynamics and that its effect on metapopulation stability is opposite to that of interspecific competition on local community stability. Our results also suggest that conservation corridors should be designed with appreciation of spatial heterogeneities in population dynamics in order to maximize metapopulation stability.

  16. Movement monitoring device

    International Nuclear Information System (INIS)

    Ichikawa, Takashi; Yoneda, Yasuaki; Hanatsumi, Masaharu.

    1997-01-01

    The present invention provides a device suitable to accurate recognition for the moving state of reactor core fuels as an object to be monitored in a nuclear power plant. Namely, the device of the present invention prepares each of scheduled paths for the movement of the object to be monitored and executed moving paths along with the movement based on the information of the movement obtained from scheduled information for the movement of the reactor core fuels as a object to be monitored and the actual movement of the object to be monitored. The results of the preparation are outputted. As an output mode, (1) the results of preparation for each of the paths for movement and the results of the monitoring obtained by monitoring the state of the object to be monitored are jointed and outputted, (2) images showing each of the paths for the movement are formed, and the formed images are displayed on a screen, and (3) each of the moving paths is prepared as an image, and the image is displayed together with the image of the regions before and after the movement of the object to be monitored. In addition, obtained images of each of the paths for the movement and the monitored images obtained by monitoring the state of the object to be monitored are joined and displayed. (I.S.)

  17. Classification of movement disorders.

    Science.gov (United States)

    Fahn, Stanley

    2011-05-01

    The classification of movement disorders has evolved. Even the terminology has shifted, from an anatomical one of extrapyramidal disorders to a phenomenological one of movement disorders. The history of how this shift came about is described. The history of both the definitions and the classifications of the various neurologic conditions is then reviewed. First is a review of movement disorders as a group; then, the evolving classifications for 3 of them--parkinsonism, dystonia, and tremor--are covered in detail. Copyright © 2011 Movement Disorder Society.

  18. Sensation of Movement

    DEFF Research Database (Denmark)

    Sensation of Movement will discuss the role of sensation in the control of action, bodily self-recognition, and sense of agency. Sensing movement is dependent on a range of information received by the brain, from signalling in the peripheral sensory organs to the establishment of higher order goals....... This volume will question whether one type of information is more relevant for the ability to sense and control movements, and demonstrate the importance of integrating neuroscientific knowledge with philosophical perspectives, in order to arrive at new insights into how sensation of movement can be studied...

  19. A costal dispersion model

    International Nuclear Information System (INIS)

    Rahm, L.; Nyberg, L.; Gidhagen, L.

    1990-01-01

    A dispersion model to be used off costal waters has been developed. The model has been applied to describe the migration of radionuclides in the Baltic sea. A summary of the results is presented here. (K.A.E)

  20. Wave-equation dispersion inversion

    KAUST Repository

    Li, Jing; Feng, Zongcai; Schuster, Gerard T.

    2016-01-01

    We present the theory for wave-equation inversion of dispersion curves, where the misfit function is the sum of the squared differences between the wavenumbers along the predicted and observed dispersion curves. The dispersion curves are obtained

  1. Evolution of density-dependent movement during experimental range expansions.

    Science.gov (United States)

    Fronhofer, E A; Gut, S; Altermatt, F

    2017-12-01

    Range expansions and biological invasions are prime examples of transient processes that are likely impacted by rapid evolutionary changes. As a spatial process, range expansions are driven by dispersal and movement behaviour. Although it is widely accepted that dispersal and movement may be context-dependent, for instance density-dependent, and best represented by reaction norms, the evolution of density-dependent movement during range expansions has received little experimental attention. We therefore tested current theory predicting the evolution of increased movement at low densities at range margins using highly replicated and controlled range expansion experiments across multiple genotypes of the protist model system Tetrahymena thermophila. Although rare, we found evolutionary changes during range expansions even in the absence of initial standing genetic variation. Range expansions led to the evolution of negatively density-dependent movement at range margins. In addition, we report the evolution of increased intrastrain competitive ability and concurrently decreased population growth rates in range cores. Our findings highlight the importance of understanding movement and dispersal as evolving reaction norms and plastic life-history traits of central relevance for range expansions, biological invasions and the dynamics of spatially structured systems in general. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

  2. Reactimeter dispersion equation

    OpenAIRE

    A.G. Yuferov

    2016-01-01

    The aim of this work is to derive and analyze a reactimeter metrological model in the form of the dispersion equation which connects reactimeter input/output signal dispersions with superimposed random noise at the inlet. It is proposed to standardize the reactimeter equation form, presenting the main reactimeter computing unit by a convolution equation. Hence, the reactimeter metrological characteristics are completely determined by this unit hardware function which represents a transient re...

  3. Fickian dispersion is anomalous

    Science.gov (United States)

    Cushman, John H.; O'Malley, Dan

    2015-12-01

    The thesis put forward here is that the occurrence of Fickian dispersion in geophysical settings is a rare event and consequently should be labeled as anomalous. What people classically call anomalous is really the norm. In a Lagrangian setting, a process with mean square displacement which is proportional to time is generally labeled as Fickian dispersion. With a number of counter examples we show why this definition is fraught with difficulty. In a related discussion, we show an infinite second moment does not necessarily imply the process is super dispersive. By employing a rigorous mathematical definition of Fickian dispersion we illustrate why it is so hard to find a Fickian process. We go on to employ a number of renormalization group approaches to classify non-Fickian dispersive behavior. Scaling laws for the probability density function for a dispersive process, the distribution for the first passage times, the mean first passage time, and the finite-size Lyapunov exponent are presented for fixed points of both deterministic and stochastic renormalization group operators. The fixed points of the renormalization group operators are p-self-similar processes. A generalized renormalization group operator is introduced whose fixed points form a set of generalized self-similar processes. Power-law clocks are introduced to examine multi-scaling behavior. Several examples of these ideas are presented and discussed.

  4. Dispersant field testing : a review of procedures and considerations

    International Nuclear Information System (INIS)

    Fingas, M.F.

    2004-01-01

    The effectiveness of a dispersant is defined by the amount of oil that the dispersant puts into the water column compared to the amount of oil that was initially spilled. Effectiveness is generally determined visually in plumes of dispersed oil that are visible from ships and aircraft. This paper describes 25 specific issues and technical concerns regarding field testing of dispersant effectiveness. Recent field tests were reviewed and literature that relates to testing procedures was sited. The 25 factors that are important for the appropriate outcome of dispersant field experiments include: mass balance; proper controls; analytical method; differential plume movement; time lag and length of time followed; mathematics of calculation and integration; lower and upper limits of analytical methods; use of remote sensing; thickness measurement; behaviour of oil with surfactant content; surfactant stripping; tracking surface oil and dispersed oil; recovering surface oil; visibility of oil from the surface; background levels of hydrocarbons; fluorescence of dispersant; herding; emulsion breaking; application success; heterogeneity of slick and plume; deposition measurements; true analytical standards; effect of wind on dispersant and slick; dispersant run-off; and weathering of the oil. It was concluded that the most important factors are the ability to determine mass balance, use proper controls, analytical methods and to avoid procedures that give incorrect results. 34 refs., 4 tabs., 1 fig

  5. Exploring pedestrian movement patterns

    NARCIS (Netherlands)

    Orellana, D.A.

    2012-01-01

    The main objective of this thesis is to develop an approach for exploring, analysing and interpreting movement patterns of pedestrians interacting with the environment. This objective is broken down in sub-objectives related to four research questions. A case study of the movement of visitors in a

  6. [Dance/Movement Therapy.

    Science.gov (United States)

    Fenichel, Emily, Ed.

    1994-01-01

    This newsletter theme issue focuses on dance, play, and movement therapy for infants and toddlers with disabilities. Individual articles are: "Join My Dance: The Unique Movement Style of Each Infant and Toddler Can Invite Communication, Expression and Intervention" (Suzi Tortora); "Dynamic Play Therapy: An Integrated Expressive Arts Approach to…

  7. Dynamics of human movement

    NARCIS (Netherlands)

    Koopman, Hubertus F.J.M.

    2010-01-01

    The part of (bio)mechanics that studies the interaction of forces on the human skeletal system and its effect on the resulting movement is called rigid body dynamics. Some basic concepts are presented: A mathematical formulation to describe human movement and how this relates on the mechanical loads

  8. Characteristics of lesser prairie-chicken (Tympanuchus pallidicinctus) long-distance movements across their distribution

    Science.gov (United States)

    Earl, Julia E.; Fuhlendorf, Samuel D.; Haukos, David A.; Tanner, Ashley M.; Elmore, Dwayne; Carleton, Scott A.

    2016-01-01

    Long-distance movements are important adaptive behaviors that contribute to population, community, and ecosystem connectivity. However, researchers have a poor understanding of the characteristics of long-distance movements for most species. Here, we examined long-distance movements for the lesser prairie-chicken (Tympanuchus pallidicinctus), a species of conservation concern. We addressed the following questions: (1) At what distances could populations be connected? (2) What are the characteristics and probability of dispersal movements? (3) Do lesser prairie-chickens display exploratory and round-trip movements? (4) Do the characteristics of long-distance movements vary by site? Movements were examined from populations using satellite GPS transmitters across the entire distribution of the species in New Mexico, Oklahoma, Kansas, and Colorado. Dispersal movements were recorded up to 71 km net displacement, much farther than hitherto recorded. These distances suggest that there may be greater potential connectivity among populations than previously thought. Dispersal movements were displayed primarily by females and had a northerly directional bias. Dispersal probabilities ranged from 0.08 to 0.43 movements per year for both sexes combined, although these movements averaged only 16 km net displacement. Lesser prairie-chickens displayed both exploratory foray loops and round-trip movements. Half of round-trip movements appeared seasonal, suggesting a partial migration in some populations. None of the long-distance movements varied by study site. Data presented here will be important in parameterizing models assessing population viability and informing conservation planning, although further work is needed to identify landscape features that may reduce connectivity among populations.

  9. The devil is in the dispersers: Predictions of landscape connectivity change with demography

    Science.gov (United States)

    Nicholas B. Elliot; Samuel A. Cushman; David W. Macdonald; Andrew J. Loveridge

    2014-01-01

    Concern about the effects of habitat fragmentation has led to increasing interest in dispersal and connectivity modelling. Most modern techniques for connectivity modelling have resistance surfaces as their foundation. However, resistance surfaces for animal movement are frequently estimated without considering dispersal, despite being the principal natural mechanism...

  10. Islamic Puritanism Movements in Indonesia as Transnational Movements

    Directory of Open Access Journals (Sweden)

    Benny Baskara

    2017-04-01

    Full Text Available Islamic puritanism movements are the movements compelling to return to the teachings of Quran and Sunnah, as the pure teachings of Islam and abandon even abolish other teachings outside the teachings of Quran and Sunnah. The movements of Islamic puritanism can be considered as transnational movements because they spread their teachings and ideologies, create organizations, networks, and provide financial supports across nations. This paper describes Islamic puritanism movements in Indonesia and their transnational connections. Some Islamic puritanism movements in Indonesia can be considered as part of Islamic transnational movements, in which most of the movements are centered in the Middle East. In Indonesia, Islamic puritanism movements firstly appeared in the beginning of the nineteenth century, called Padri movement in West Sumatra. It was then continued to the emergence of Islamic organizations in the twentieth century. Recently, Islamic puritanism movements in Indonesia mostly take form as Salafism-Wahabism movements.

  11. Coping with power dispersion?

    DEFF Research Database (Denmark)

    2014-01-01

    The last decades have witnessed a significant shift in policy competences away from central governments in Europe. The reallocation of competences spans over three dimensions: upwards; sideways; and downwards. This collection takes the dispersion of powers as a starting point and seeks to assess...... how the actors involved cope with the new configurations. In this introduction, we discuss the conceptualization of power dispersion and highlight the ways in which the contributions add to this research agenda. We then outline some general conclusions and end by indicating future avenues of research....... Taken together, the collection contributes some answers to the challenge of defining and measuring – in a comparative way – the control and co-ordination mechanisms which power dispersion generates. It also explores the tension between political actors' quest for autonomy and the acknowledgement...

  12. The Irish Women's Movement

    OpenAIRE

    Cullen, Pauline

    2015-01-01

    Ireland’s long history of patriarchy is matched by the ongoing evolution of its women’s movements. Today’s complex, transnational feminism finds its precursor in the colonial era. The first wave of the Irish women’s movement dates from the mid-19th century, with the franchise secured for women in 1918 while still under British colonial rule. First-wave feminists played a role in the nationalist movement, but their demands were sidelined later, during the construction of a conserva...

  13. Music and movement

    OpenAIRE

    Nasev, Lence

    2012-01-01

    Rhythm is one of the fundamental elements without which music would not exist. In plays with singing, a child learns to synchronize its movements with the rhythm of music from a very early age. The skill of movement plays a major role in the learning of music and thus deserves an important place in the school curriculum. In this paper, an overview is made of the most important music pedagogues who introduced movement, and at the same time perceived its importance in learning musical conte...

  14. Movement behavior explains genetic differentiation in American black bears

    Science.gov (United States)

    Samuel A Cushman; Jesse S. Lewis

    2010-01-01

    Individual-based landscape genetic analyses provide empirically based models of gene flow. It would be valuable to verify the predictions of these models using independent data of a different type. Analyses using different data sources that produce consistent results provide strong support for the generality of the findings. Mating and dispersal movements are the...

  15. Radioisotope studies on the paradox in dispersion and agglomeration of sewage greases discharged from ocean outfalls

    International Nuclear Information System (INIS)

    Davison, A.; Easy, J.F.; Seatonberry, B.W.

    1981-04-01

    Experiments have been undertaken in the ocean off Sydney, Australia to monitor the movement and the dispersion of sewage solids. These solids were labelled with a radioisotope, gold-198 prior to ocean discharge. The labelled material was followed at sea using submersible scintillation detectors. Lateral and vertical dispersion coefficients were determined. The experiments showed that under some conditions the labelled sewage grease dispersed and under others the grease agglomerated. This variation is explained in terms of non-conservative processes

  16. Applying Movement Ecology to Marine Animals with Complex Life Cycles

    Science.gov (United States)

    Allen, Richard M.; Metaxas, Anna; Snelgrove, Paul V. R.

    2018-01-01

    Marine animals with complex life cycles may move passively or actively for fertilization, dispersal, predator avoidance, resource acquisition, and migration, and over scales from micrometers to thousands of kilometers. This diversity has catalyzed idiosyncratic and unfocused research, creating unsound paradigms regarding the role of movement in ecology and evolution. The emerging movement ecology paradigm offers a framework to consolidate movement research independent of taxon, life-history stage, scale, or discipline. This review applies the framework to movement among life-history stages in marine animals with complex life cycles to consolidate marine movement research and offer insights for scientists working in aquatic and terrestrial realms. Irrespective of data collection or simulation strategy, breaking each life-history stage down into the fundamental units of movement allows each unit to be studied independently or interactively with other units. Understanding these underlying mechanisms of movement within each life-history stage can then be used to construct lifetime movement paths. These paths can allow further investigation of the relative contributions and interdependencies of steps and phases across a lifetime and how these paths influence larger research topics, such as population-level movements.

  17. The French ecological movement

    International Nuclear Information System (INIS)

    Sansen, Bernard

    1977-01-01

    The analysis of the ecological Movement in France is presented: its organisation, its topics, its position with respect to the main political trends. The accent is put in particular on the antinuclear contestation [fr

  18. Movement and personality development

    Directory of Open Access Journals (Sweden)

    Aida M. Aylamazyan

    2017-06-01

    Full Text Available The paper discusses the role of the movement in the process of shaping the personality, its importance as a mechanism for personality development is considered. The issue of the movement has always occupied a central place in Russian psychology. However, subsequently the movement began to be considered primarily as an executive action in human life. The role of movement in personality development can vary depending on the level it occupies in the hierarchical structure of activity, and also on the type of movement, its character, and the way it is constructed. Under certain conditions, the movement can express the attitude of the subject to the surrounding world and people. Many foreign and Russian psychologists point to a special place of the postural tonic component of the motor movement, the posture in personal regulation. The posture reflects his/her personal attitudes, the system of relationships, and, above all, the emotional attitude or emotional assessment of the current situation, the interest in the actions performed. Mastering the tonic level of motor management is based on the emotional regulation, so the ability to regulate one’s own pose is an important stage in the personality development. Posture tonic regulation of motor movements in humans reveals a qualitatively different character than in animals, this being due to the person’s facing the task of mastering his’her posture, arbitrary retention of the body in one or another position. Maintaining a vertical posture requires constant activity at an arbitrary and involuntary level of mental regulation. Mastering the posture of an unstable equilibrium presupposes the emergence of the «I» and is the last stage of the development. The way a person solves the motor task of maintaining the vertical position of the body reflects his/her specific personal strategy or attitude.

  19. Rooted in Movement

    DEFF Research Database (Denmark)

    The result of the synergy between four doctoral projects and an advanced MA-level course on Bronze Age Europe, this integrated assemblage of articles represents a variety of different subjects united by a single theme: movement. Ranging from theoretical discussion of the various responses to and ...... period of European prehistory. In so doing, the text not only addresses transmission and reception, but also the conceptualization of mobility within a world which was literally Rooted in Movement....

  20. Paraneoplastic autoimmune movement disorders.

    Science.gov (United States)

    Lim, Thien Thien

    2017-11-01

    To provide an overview of paraneoplastic autoimmune disorders presenting with various movement disorders. The spectrum of paraneoplastic autoimmune disorders has been expanding with the discovery of new antibodies against cell surface and intracellular antigens. Many of these paraneoplastic autoimmune disorders manifest as a form of movement disorder. With the discovery of new neuronal antibodies, an increasing number of idiopathic or neurodegenerative movement disorders are now being reclassified as immune-mediated movement disorders. These include anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis which may present with orolingual facial dyskinesia and stereotyped movements, CRMP-5 IgG presenting with chorea, anti-Yo paraneoplastic cerebellar degeneration presenting with ataxia, anti-VGKC complex (Caspr2 antibodies) neuromyotonia, opsoclonus-myoclonus-ataxia syndrome, and muscle rigidity and episodic spasms (amphiphysin, glutamic acid decarboxylase, glycine receptor, GABA(A)-receptor associated protein antibodies) in stiff-person syndrome. Movement disorders may be a presentation for paraneoplastic autoimmune disorders. Recognition of these disorders and their common phenomenology is important because it may lead to the discovery of an occult malignancy. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Nuclear movement in fungi.

    Science.gov (United States)

    Xiang, Xin

    2017-12-11

    Nuclear movement within a cell occurs in a variety of eukaryotic organisms including yeasts and filamentous fungi. Fungal molecular genetic studies identified the minus-end-directed microtubule motor cytoplasmic dynein as a critical protein for nuclear movement or orientation of the mitotic spindle contained in the nucleus. Studies in the budding yeast first indicated that dynein anchored at the cortex via its anchoring protein Num1 exerts pulling force on an astral microtubule to orient the anaphase spindle across the mother-daughter axis before nuclear division. Prior to anaphase, myosin V interacts with the plus end of an astral microtubule via Kar9-Bim1/EB1 and pulls the plus end along the actin cables to move the nucleus/spindle close to the bud neck. In addition, pushing or pulling forces generated from cortex-linked polymerization or depolymerization of microtubules drive nuclear movements in yeasts and possibly also in filamentous fungi. In filamentous fungi, multiple nuclei within a hyphal segment undergo dynein-dependent back-and-forth movements and their positioning is also influenced by cytoplasmic streaming toward the hyphal tip. In addition, nuclear movement occurs at various stages of fungal development and fungal infection of plant tissues. This review discusses our current understanding on the mechanisms of nuclear movement in fungal organisms, the importance of nuclear positioning and the regulatory strategies that ensure the proper positioning of nucleus/spindle. Published by Elsevier Ltd.

  2. Antiglobalization movements and their critics

    DEFF Research Database (Denmark)

    Corry, Olaf

    2012-01-01

    inequity, organize transnationally, and maintain a critical stance toward significant aspects of the state system. For this reason, many supporters favor other terms such as alterglobalization movement, global justice movement , or simply the movement of movements . Critics accuse the movements...... of ideological incoherence, self-interested protectionism, and illiberal and undemocratic political methods, and point to Western liberal elite dominance within the movements. The debate has ...

  3. Interface, a dispersed architecture

    NARCIS (Netherlands)

    Vissers, C.A.

    1976-01-01

    Past and current specification techniques use timing diagrams and written text to describe the phenomenology of an interface. This paper treats an interface as the architecture of a number of processes, which are dispersed over the related system parts and the message path. This approach yields a

  4. Psychorheology of food dispersions

    Czech Academy of Sciences Publication Activity Database

    Štern, Petr; Panovská, Z.; Pokorný, J.

    2010-01-01

    Roč. 58, č. 1 (2010), s. 29-35 ISSN 0042-790X R&D Projects: GA AV ČR IAA2060404 Institutional research plan: CEZ:AV0Z20600510 Keywords : psychorheology * food dispersions * tomato ketchup * rheology * sensory analysis Subject RIV: BK - Fluid Dynamics Impact factor: 0.553, year: 2010

  5. Dispersal of sticky particles

    Science.gov (United States)

    Reddy, Ramana; Kumar, Sanjeev

    2007-12-01

    In this paper, we show through simulations that when sticky particles are broken continually, particles are dispersed into fine dust only if they are present in a narrow range of volume fractions. The upper limit of this range is 0.20 in the 2D and 0.10 in the 3D space. An increase in the dimensionality of space reduces the upper limit nearly by a factor of two. This scaling holds for dispersal of particles in hyperdimensional space of dimensions up to ten, the maximum dimension studied in this work. The maximum values of volume fractions obtained are significantly lower than those required for close packing and random packing of discs in 2D and spheres in 3D space. These values are also smaller than those required for critical phenomena of cluster percolation. The results obtained are attributed to merger cascades of sticky particles, triggered by breakup events. A simple theory that incorporates this cascade is developed to quantitatively explain the observed scaling of the upper limit with the dimensionality of space. The theory also captures the dynamics of the dispersal process in the corresponding range of particle volume fractions. The theory suggests that cascades of order one and two predominantly decide the upper limit for complete dispersal of particles.

  6. Aquatic dispersion modelling of a tritium plume in Lake Ontario

    International Nuclear Information System (INIS)

    Klukas, M.H.; Moltyaner, G.L.

    1996-05-01

    Approximately 2900 kg of tritiated water, containing 2.3E+15 Bq of tritium, were released to Lake Ontario via the cooling water discharge when a leak developed in a moderator heat exchanger in Unit 1 at the Pickering Nuclear Generating Station (PNGS) on 1992 August 2. The release provided the opportunity to study the dispersion of a tritium plume in the coastal zone of Lake Ontario. Current direction over the two-week period following the release was predominantly parallel to the shore, and elevated tritium concentrations were observed up to 20 km east and 85 km west of the PNGS. Predictions of the tritium plume movement were made using current velocity measurements taken at 8-m depth, 2.5 km offshore from Darlington and using a empirical relationship where alongshore current speed is assumed to be proportional to the alongshore component of the wind speed. The tritium migration was best described using current velocity measurements. The tritium plume dispersion is modelled using the one-dimensional advection-dispersion equation. Transport parameters are the alongshore current speed and longitudinal dispersion coefficient. Longitudinal dispersion coefficients, estimated by fitting the solution of the advection-dispersion equation to measured concentration distance profiles ranged from 3.75 to 10.57 m 2 s -1 . Simulations using the fitted values of the dispersion coefficient were able to describe maximum tritium concentrations measured at water supply plants located within 25 km of Pickering to within a factor of 3. The dispersion coefficient is a function of spatial and temporal variability in current velocity and the fitted dispersion coefficients estimated here may not be suitable for predicting tritium plume dispersion under different current conditions. The sensitivity of the dispersion coefficient to variability in current conditions should be evaluated in further field experiments. (author). 13 refs., 7 tabs., 12 figs

  7. [Scenes in movement. Movement disorders on film].

    Science.gov (United States)

    Olivares Romero, J

    2010-03-01

    There are publications in which various neurological diseases are analysed on film. However, no references have been found on movement disorders in this medium. A total of 104 documents were collected and reviewed using the internet movie data base (IMDb). The majority were associated with dystonia, Parkinson's and tics, were American commercial productions, and the most common genre was drama. The cinema usually depicts old men with developed Parkinson's disease. However, motor complications only appear in 19% and non-motor symptoms in 14%. The image of dystonia is generally that of a young man, with disabling dystonia secondary to childhood cerebral palsy. Tics appear associated with Tourette's syndrome, with the excessive use of obscene expressions and with very few references to other important aspects of this syndrome, such as mood and behavioural changes. The majority of tremors portrayed on film are associated with Parkinsonism and are not pathological. Myoclonus appears anecdotically and is normally symptomatic. Parkinson's disease is the type of movement disorder that the cinema portrays with greater neurological honesty and in a more dignified manner.

  8. Dispersed flow film boiling

    International Nuclear Information System (INIS)

    Andreani, M.; Yadigaroglu, G.

    1989-12-01

    Dispersed flow film boiling is the heat transfer regime that occurs at high void fractions in a heated channel. The way this transfer mode is modelled in the NRC computer codes (RELAP5 and TRAC) and the validity of the assumption and empirical correlations used is discussed. An extensive review of the theoretical and experimental work related with heat transfer to highly dispersed mixtures reveals the basic deficiencies of these models: the investigation refers mostly to the typical conditions of low rate bottom reflooding, since the simulation of this physical situation by the computer codes has often showed poor results. The alternative models that are available in the literature are reviewed, and their merits and limits are highlighted. The modification that could improve the physics of the models implemented in the codes are identified. (author) 13 figs., 123 refs

  9. Working document dispersion models

    International Nuclear Information System (INIS)

    Dop, H. van

    1988-01-01

    This report is a summary of the most important results from June 1985 of the collaboration of the RIVM (Dutch National Institute for Public Health and Environment Hygiene) and KNMI (Royal Dutch Meteorologic Institute) on the domain of dispersion models. It contains a short description of the actual SO x /NO x -model. Furthermore it contains recommendations for modifications of some numerical-mathematical aspects and an impulse to a more complete description of chemical processes in the atmosphere and the (wet) deposition process. A separate chapter is devoted to the preparation of meteorologic data which are relevant for dispersion as well as atmospheric chemistry and deposition. This report serves as working document for the final formulation of a acidifying- and oxidant-model. (H.W.). 69 refs.; 51 figs.; 13 tabs.; 3 schemes

  10. Spatially Dispersed Employee Recovery

    DEFF Research Database (Denmark)

    Hvass, Kristian Anders; Torfadóttir, Embla

    2014-01-01

    Employee recovery addresses either employee well-being or management's practices in aiding employees in recovering themselves following a service failure. This paper surveys the cabin crew at a small, European, low-cost carrier and investigates employees' perceptions of management practices to aid...... personnel achieve service recovery. Employee recovery within service research often focuses on front-line employees that work in a fixed location, however a contribution to the field is made by investigating the recovery of spatially dispersed personnel, such as operational personnel in the transport sector......, who have a work place away from a fixed or central location and have minimal management contact. Results suggest that the support employees receive from management, such as recognition, information sharing, training, and strategic awareness are all important for spatially dispersed front...

  11. Heat dispersion in rivers

    International Nuclear Information System (INIS)

    Shaw, T.L.

    1974-01-01

    One of the tasks of the Sonderforschungsbereich 80 is to study the dispersion of heat discharged into rivers and other bodies of water and to develop methods which permit prediction of detrimental effects caused by the heated discharges. In order to help the SFB 80 to specify this task, Dr. Shaw, lecturer of Civil Engineering at the Bristol University, conducted a literature survey on heat-dispersion studies during the two months which he spent as a visiting research fellow with the SFB 80 at the University of Karlsruhe in the summer of 1973. The following report is the outcome of this survey. It gives Dr. Shaw's assessment of the present state of knowledge - based almost exclusively on literature in the English language - and compares this with the knowledge required by river planners. The apparent discrepancy leads to suggestions for future research. Selected references as well as a representative bibliography can be found at the end of the report. (orig.) [de

  12. Studying Social Movements

    DEFF Research Database (Denmark)

    Uldam, Julie; McCurdy, Patrick

    2013-01-01

    The research method of participant observation has long been used by scholars interested in the motivations, dynamics, tactics and strategies of social movements from a movement perspective. Despite participant observation being a common research method, there have been very few efforts to bring...... together this literature, which has often been spread across disciplines. This makes it difficult to identify the various challenges (and their interrelation) facing participant observers. Consequently, this article first reviews how participant observation roles have been conceptualised in general...... and then draws specific links to how the method has been used in the study of activism and social movements. In doing so, this article brings together key academic debates on participant observation, which have been considered separately, such as insider/outsider and overt/covert, but not previously been brought...

  13. Movement as utopia.

    Science.gov (United States)

    Couton, Philippe; López, José Julián

    2009-10-01

    Opposition to utopianism on ontological and political grounds has seemingly relegated it to a potentially dangerous form of antiquated idealism. This conclusion is based on a restrictive view of utopia as excessively ordered panoptic discursive constructions. This overlooks the fact that, from its inception, movement has been central to the utopian tradition. The power of utopianism indeed resides in its ability to instantiate the tension between movement and place that has marked social transformations in the modern era. This tension continues in contemporary discussions of movement-based social processes, particularly international migration and related identity formations, such as open borders transnationalism and cosmopolitanism. Understood as such, utopia remains an ongoing and powerful, albeit problematic instrument of social and political imagination.

  14. Taylor dispersion of nanoparticles

    Science.gov (United States)

    Balog, Sandor; Urban, Dominic A.; Milosevic, Ana M.; Crippa, Federica; Rothen-Rutishauser, Barbara; Petri-Fink, Alke

    2017-08-01

    The ability to detect and accurately characterize particles is required by many fields of nanotechnology, including materials science, nanotoxicology, and nanomedicine. Among the most relevant physicochemical properties of nanoparticles, size and the related surface-to-volume ratio are fundamental ones. Taylor dispersion combines three independent phenomena to determine particle size: optical extinction, translational diffusion, and sheer-enhanced dispersion of nanoparticles subjected to a steady laminar flow. The interplay of these defines the apparent size. Considering that particles in fact are never truly uniform nor monodisperse, we rigorously address particle polydispersity and calculate the apparent particle size measured by Taylor dispersion analysis. We conducted case studies addressing aqueous suspensions of model particles and large-scale-produced "industrial" particles of both academic and commercial interest of various core materials and sizes, ranging from 15 to 100 nm. A comparison with particle sizes determined by transmission electron microscopy confirms that our approach is model-independent, non-parametric, and of general validity that provides an accurate account of size polydispersity—independently on the shape of the size distribution and without any assumption required a priori.

  15. Breeding Dispersal by Birds in a Dynamic Urban Ecosystem.

    Science.gov (United States)

    Marzluff, John M; DeLap, Jack H; Oleyar, M David; Whittaker, Kara A; Gardner, Beth

    2016-01-01

    Changes in land cover during urbanization profoundly affect the diversity of bird communities, but the demographic mechanisms affecting diversity are poorly known. We advance such understanding by documenting how urbanization influences breeding dispersal-the annual movement of territorial adults-of six songbird species in the Seattle, WA, USA metropolitan area. We color-banded adults and mapped the centers of their annual breeding activities from 2000-2010 to obtain 504 consecutive movements by 337 adults. By comparing movements, annual reproduction, and mate fidelity among 10 developed, 5 reserved, and 11 changing (areas cleared and developed during our study) landscapes, we determined that adaptive breeding dispersal of sensitive forest species (Swainson's Thrush and Pacific wren), which involves shifting territory and mate after reproductive failure, was constrained by development. In changing lands, sensitive forest specialists dispersed from active development to nearby forested areas, but in so doing suffered low annual reproduction. Species tolerant of suburban lands (song sparrow, spotted towhee, dark-eyed junco, and Bewick's wren) dispersed adaptively in changing landscapes. Site fidelity ranged from 0% (Pacific wren in changing landscape) to 83% (Bewick's wren in forest reserve). Mate fidelity ranged from 25% (dark-eyed junco) to 100% (Bewick's wren). Variation in fidelity to mate and territory was consistent with theories positing an influence of territory quality, asynchronous return from migration, prior productivity, and reproductive benefits of retaining a familiar territory. Costly breeding dispersal, as well as reduced reproductive success and lowered survival cause some birds to decline in the face of urbanization. In contrast, the ability of species that utilize edges and early successional habitats to breed successfully, disperse to improve reproductive success after failure, and survive throughout the urban ecosystem enables them to maintain

  16. Breeding Dispersal by Birds in a Dynamic Urban Ecosystem.

    Directory of Open Access Journals (Sweden)

    John M Marzluff

    Full Text Available Changes in land cover during urbanization profoundly affect the diversity of bird communities, but the demographic mechanisms affecting diversity are poorly known. We advance such understanding by documenting how urbanization influences breeding dispersal-the annual movement of territorial adults-of six songbird species in the Seattle, WA, USA metropolitan area. We color-banded adults and mapped the centers of their annual breeding activities from 2000-2010 to obtain 504 consecutive movements by 337 adults. By comparing movements, annual reproduction, and mate fidelity among 10 developed, 5 reserved, and 11 changing (areas cleared and developed during our study landscapes, we determined that adaptive breeding dispersal of sensitive forest species (Swainson's Thrush and Pacific wren, which involves shifting territory and mate after reproductive failure, was constrained by development. In changing lands, sensitive forest specialists dispersed from active development to nearby forested areas, but in so doing suffered low annual reproduction. Species tolerant of suburban lands (song sparrow, spotted towhee, dark-eyed junco, and Bewick's wren dispersed adaptively in changing landscapes. Site fidelity ranged from 0% (Pacific wren in changing landscape to 83% (Bewick's wren in forest reserve. Mate fidelity ranged from 25% (dark-eyed junco to 100% (Bewick's wren. Variation in fidelity to mate and territory was consistent with theories positing an influence of territory quality, asynchronous return from migration, prior productivity, and reproductive benefits of retaining a familiar territory. Costly breeding dispersal, as well as reduced reproductive success and lowered survival cause some birds to decline in the face of urbanization. In contrast, the ability of species that utilize edges and early successional habitats to breed successfully, disperse to improve reproductive success after failure, and survive throughout the urban ecosystem enables them

  17. Movement Without Boundaries

    Directory of Open Access Journals (Sweden)

    Jennifer Fortuna

    2017-10-01

    Full Text Available Johnson Simon, an artist based in West Palm Beach, FL, provided the cover art for the Fall 2017 edition of The Open Journal of Occupational Therapy (OJOT. “Dancing in Motion” is a 36” x 60” painting made from acrylic on canvas. Johnson always wanted to become a dancer. He was born with cerebral palsy, and therefore physical limitations make it difficult for Johnson to coordinate his body movements. Through use of vibrant colors and bold strokes, Johnson’s expressionist paintings evoke movement and motion. Occupational therapy helped Johnson discover his artistic abilities. Painting empowered him to move without limitations

  18. Nozzle for electric dispersion reactor

    Science.gov (United States)

    Sisson, W.G.; Basaran, O.A.; Harris, M.T.

    1995-11-07

    A nozzle for an electric dispersion reactor includes two concentric electrodes, the inner one of the two delivering disperse phase fluid into a continuous phase fluid. A potential difference generated by a voltage source creates a dispersing electric field at the end of the inner electrode. 4 figs.

  19. A movement ecology paradigm for unifying organismal movement research.

    Science.gov (United States)

    Nathan, Ran; Getz, Wayne M; Revilla, Eloy; Holyoak, Marcel; Kadmon, Ronen; Saltz, David; Smouse, Peter E

    2008-12-09

    Movement of individual organisms is fundamental to life, quilting our planet in a rich tapestry of phenomena with diverse implications for ecosystems and humans. Movement research is both plentiful and insightful, and recent methodological advances facilitate obtaining a detailed view of individual movement. Yet, we lack a general unifying paradigm, derived from first principles, which can place movement studies within a common context and advance the development of a mature scientific discipline. This introductory article to the Movement Ecology Special Feature proposes a paradigm that integrates conceptual, theoretical, methodological, and empirical frameworks for studying movement of all organisms, from microbes to trees to elephants. We introduce a conceptual framework depicting the interplay among four basic mechanistic components of organismal movement: the internal state (why move?), motion (how to move?), and navigation (when and where to move?) capacities of the individual and the external factors affecting movement. We demonstrate how the proposed framework aids the study of various taxa and movement types; promotes the formulation of hypotheses about movement; and complements existing biomechanical, cognitive, random, and optimality paradigms of movement. The proposed framework integrates eclectic research on movement into a structured paradigm and aims at providing a basis for hypothesis generation and a vehicle facilitating the understanding of the causes, mechanisms, and spatiotemporal patterns of movement and their role in various ecological and evolutionary processes. "Now we must consider in general the common reason for moving with any movement whatever." (Aristotle, De Motu Animalium, 4th century B.C.).

  20. Rationality in Human Movement.

    Science.gov (United States)

    O'Brien, Megan K; Ahmed, Alaa A

    2016-01-01

    It long has been appreciated that humans behave irrationally in economic decisions under risk: they fail to objectively consider uncertainty, costs, and rewards and instead exhibit risk-seeking or risk-averse behavior. We hypothesize that poor estimates of motor variability (influenced by motor task) and distorted probability weighting (influenced by relevant emotional processes) contribute to characteristic irrationality in human movement decisions.

  1. The Matter of Movement

    DEFF Research Database (Denmark)

    Ayres, Phil

    2015-01-01

    This contribution concerns itself with the design and realisation of architectures that operate with material dynamics. It presents this concern as a counter to the consideration of movement in architecture as something conceptualised from the position of the observer. The contribution draws upon...

  2. Knowledge through movement

    DEFF Research Database (Denmark)

    Jensen, Søren Kjær; Moser, T.

    2003-01-01

    In: Children and adolescents in movement - perspectives and ideas. The Danish Ministry of Culture, pages 150 - 162. 2003 Short description: the article debunks a lot of the myths surrounding body and learning, and replace them with a vision about another kind of learning. The aim is to reintroduce...

  3. Mungiki as Youth Movement

    DEFF Research Database (Denmark)

    Rasmussen, Jacob

    2010-01-01

    Like many other African countries, Kenya has a large and growing youth population. Some of the youths are mobilized into militant and political networks; one of these is the Mungiki movement. The article explores Mungiki’s combination of politics, religion and Kikuyu traditions. Using the examples...

  4. The Evidence Movement

    DEFF Research Database (Denmark)

    Hansen, Hanne Foss; Rieper, Olaf

    2009-01-01

    The evidence movement and the idea of systematic reviews, defined as summaries of the results of already existing evaluation and research projects, have gained considerable support in recent years as many international as well as national evidence-producing organizations have been established...

  5. Managing Movement as Partnership

    Science.gov (United States)

    Kimbrell, Sinead

    2011-01-01

    The associate director of education at Hubbard Street Dance Chicago recounts her learning and teaching through managing the Movement as Partnership program. Included are detailed descriptions of encounters with teachers and students as they create choreography reflective of their inquiry into integrating dance and literacy arts curriculum in the…

  6. Music, Movement, and Poetry.

    Science.gov (United States)

    Carmichael, Karla D.

    This paper's premise is that music, movement, and poetry are unique and creative methods to be used by the counselor in working with both children and adults. Through these media, the counselor generates material for the counseling session that may not be available through more traditional "talk therapies." The choice of music as a counseling…

  7. Editorial: Body Movements

    Directory of Open Access Journals (Sweden)

    Carina Assuncao

    2018-01-01

    Full Text Available Today, the juxtaposition between physical bodies and the gameworld is ever more fluid. Virtual Reality headsets are available at game stores with more AAA games being created for the format. The release of the Nintendo Switch and its dynamic JoyCon controllers reintroduce haptic movement based controls.  Pokémon GO’s augmented reality took gamers outdoors and has encouraged the Harry Potter franchise to follow in its mobile footsteps. Each development encourages a step further into the digital world. At the same time, the movement of bodies always has political dimensions. We live in a world where walls seem like solutions to the movement of bodies, while the mere meeting of bodies elsewhere – for sex, marriage and other reasons – is still forbidden by many states’ rules. Games and game-like interfaces have shown the ability to bend those rules, and to sometimes project other worlds and rule systems over our world in order to make bodies move and meet. For this special issue on ‘Body Movements’, Press Start invited authors to focus on embodiment, body movements, political bodies, community bodies, virtual bodies, physical bodies, feminine, masculine, trans- bodies, agency or its lack, and anything else in between. The response to this invitation was variegated, and provocative, as outlined here.

  8. Morocco's February 20 Movement

    African Journals Online (AJOL)

    2018-02-20

    Feb 20, 2018 ... Council for the Development of Social Science Research in Africa, 2017 ... revolted several times, namely in big cities like Casablanca, Marrakech or .... region in order to take advantage of their experience and acquire a regional ..... Undoubtedly, with social networking, the dynamics of protest movements.

  9. [Architecture and movement].

    Science.gov (United States)

    Rivallan, Armel

    2012-01-01

    Leading an architectural project means accompanying the movement which it induces within the teams. Between questioning, uncertainty and fear, the organisational changes inherent to the new facility must be subject to constructive and ongoing exchanges. Ethics, safety and training are revised and the unit projects are sometimes modified.

  10. The Theory of Thermodynamics for Chemical Reactions in Dispersed Heterogeneous Systems

    Science.gov (United States)

    Yongqiang; Baojiao; Jianfeng

    1997-07-01

    In this paper, the expressions of Gibbs energy change, enthalpy change, entropy change, and equilibrium constant for chemical reactions in dispersed heterogeneous systems are derived using classical thermodynamics theory. The thermodynamical relations for the same reaction system between the dispersed and the block state are also derived. The effects of degree of dispersion on thermodynamical properties, reaction directions, and chemical equilibria are discussed. The results show that the present equation of thermodynamics for chemical reactions is only a special case of the above-mentioned formulas and that the effect of the dispersity of a heterogeneous system on the chemical reaction obeys the Le Chatelier principle of movement of equilibria.

  11. Tracer dispersion - experiment and CFD

    International Nuclear Information System (INIS)

    Zitny, R.

    2004-01-01

    Description of tracer distribution by means of dispersion models is a method successfully used in process engineering for fifty years. Application of dispersion models in reactor engineering for characterization of flows in column apparatus, heat exchangers, etc. is summarized and experimental tracer techniques as well as CFD methods for dispersion coefficients evaluation are discussed. Possible extensions of thermal axial dispersion model (ADM) and a core-wall ADM model suitable for description of tracer dispersion in laminar flows are suggested as well as CFD implementation as 1D finite elements. (author)

  12. High density dispersion fuel

    International Nuclear Information System (INIS)

    Hofman, G.L.

    1996-01-01

    A fuel development campaign that results in an aluminum plate-type fuel of unlimited LEU burnup capability with an uranium loading of 9 grams per cm 3 of meat should be considered an unqualified success. The current worldwide approved and accepted highest loading is 4.8 g cm -3 with U 3 Si 2 as fuel. High-density uranium compounds offer no real density advantage over U 3 Si 2 and have less desirable fabrication and performance characteristics as well. Of the higher-density compounds, U 3 Si has approximately a 30% higher uranium density but the density of the U 6 X compounds would yield the factor 1.5 needed to achieve 9 g cm -3 uranium loading. Unfortunately, irradiation tests proved these peritectic compounds have poor swelling behavior. It is for this reason that the authors are turning to uranium alloys. The reason pure uranium was not seriously considered as a dispersion fuel is mainly due to its high rate of growth and swelling at low temperatures. This problem was solved at least for relatively low burnup application in non-dispersion fuel elements with small additions of Si, Fe, and Al. This so called adjusted uranium has nearly the same density as pure α-uranium and it seems prudent to reconsider this alloy as a dispersant. Further modifications of uranium metal to achieve higher burnup swelling stability involve stabilization of the cubic γ phase at low temperatures where normally α phase exists. Several low neutron capture cross section elements such as Zr, Nb, Ti and Mo accomplish this in various degrees. The challenge is to produce a suitable form of fuel powder and develop a plate fabrication procedure, as well as obtain high burnup capability through irradiation testing

  13. Spurious dispersion effects at FLASH

    International Nuclear Information System (INIS)

    Prat, Eduard

    2009-07-01

    The performance of the Free-Electron Laser (FEL) process imposes stringent demands on the transverse trajectory and size of the electron beam. Since transverse dispersion changes off-energy particle trajectories and increases the effective beam size, dispersion must be controlled. This thesis treats the concept of dispersion in linacs, and analyses the impact of dispersion on the electron beam and on the FEL process. It presents generation mechanisms for spurious dispersion, quantifying its importance for FLASH (Free-electron Laser in Hamburg) and the XFEL (European X-ray Free-Electron Laser). A method for measuring and correcting dispersion and its implementation in FLASH is described. Experiments of dispersion e ects on the transverse beam quality and on the FEL performance are presented. (orig.)

  14. Spurious dispersion effects at FLASH

    Energy Technology Data Exchange (ETDEWEB)

    Prat, Eduard

    2009-07-15

    The performance of the Free-Electron Laser (FEL) process imposes stringent demands on the transverse trajectory and size of the electron beam. Since transverse dispersion changes off-energy particle trajectories and increases the effective beam size, dispersion must be controlled. This thesis treats the concept of dispersion in linacs, and analyses the impact of dispersion on the electron beam and on the FEL process. It presents generation mechanisms for spurious dispersion, quantifying its importance for FLASH (Free-electron Laser in Hamburg) and the XFEL (European X-ray Free-Electron Laser). A method for measuring and correcting dispersion and its implementation in FLASH is described. Experiments of dispersion e ects on the transverse beam quality and on the FEL performance are presented. (orig.)

  15. Dispersion stability of thermal nanofluids

    Directory of Open Access Journals (Sweden)

    Fan Yu

    2017-10-01

    Full Text Available Thermal nanofluids, the engineered fluids with dispersed functional nanoparticles, have exhibited extraordinary thermophysical properties and added functionalities, and thus have enabled a broad range of important applications. The poor dispersion stability of thermal nanofluids, however, has been considered as a long-existing issue that limits their further development and practical application. This review overviews the recent efforts and progresses in improving the dispersion stability of thermal nanofluids such as mechanistic understanding of dispersion behavior of nanofluids, examples of both water-based and oil-based nanofluids, strategies to stabilize nanofluids, and characterization techniques for dispersion behavior of nanofluids. Finally, on-going research needs, and possible solutions to research challenges and future research directions in exploring stably dispersed thermal nanofluids are discussed. Keywords: Thermal nanofluids, Dispersion, Aggregation, Electrostatic stabilization, Steric stabilization

  16. Phonon dispersion in vanadium

    International Nuclear Information System (INIS)

    Ivanov, A.S.; Rumiantsev, A.Yu.

    1999-01-01

    Complete text of publication follows. Phonon dispersion curves in Vanadium metal are investigated by neutron inelastic scattering using three-axis spectrometers. Due to extremely low coherent scattering amplitude of neutrons in natural isotope mixture of vanadium the phonon frequencies could be determined in the energy range below about 15 meV. Several phonon groups were measured with the polarised neutron scattering set-up. It is demonstrated that the intensity of coherent inelastic scattering observed in the non-spin-flip channel vanishes in the spin-flip channel. The phonon density of states is measured on a single crystal keeping the momentum transfer equal to a vector of reciprocal lattice where the coherent inelastic scattering is suppressed. Phonon dispersion curves in vanadium, as measured by neutron and earlier by X-ray scattering, are described in frames of a charge-fluctuation model involving monopolar and dipolar degrees of freedom. The model parameters are compared for different transition metals with body-centred cubic-structure. (author)

  17. Quantum optical rotatory dispersion

    Science.gov (United States)

    Tischler, Nora; Krenn, Mario; Fickler, Robert; Vidal, Xavier; Zeilinger, Anton; Molina-Terriza, Gabriel

    2016-01-01

    The phenomenon of molecular optical activity manifests itself as the rotation of the plane of linear polarization when light passes through chiral media. Measurements of optical activity and its wavelength dependence, that is, optical rotatory dispersion, can reveal information about intricate properties of molecules, such as the three-dimensional arrangement of atoms comprising a molecule. Given a limited probe power, quantum metrology offers the possibility of outperforming classical measurements. This has particular appeal when samples may be damaged by high power, which is a potential concern for chiroptical studies. We present the first experiment in which multiwavelength polarization-entangled photon pairs are used to measure the optical activity and optical rotatory dispersion exhibited by a solution of chiral molecules. Our work paves the way for quantum-enhanced measurements of chirality, with potential applications in chemistry, biology, materials science, and the pharmaceutical industry. The scheme that we use for probing wavelength dependence not only allows one to surpass the information extracted per photon in a classical measurement but also can be used for more general differential measurements. PMID:27713928

  18. Guidelines for Using Movement Science to Inform Biodiversity Policy

    Science.gov (United States)

    Barton, Philip S.; Lentini, Pia E.; Alacs, Erika; Bau, Sana; Buckley, Yvonne M.; Burns, Emma L.; Driscoll, Don A.; Guja, Lydia K.; Kujala, Heini; Lahoz-Monfort, José J.; Mortelliti, Alessio; Nathan, Ran; Rowe, Ross; Smith, Annabel L.

    2015-10-01

    Substantial advances have been made in our understanding of the movement of species, including processes such as dispersal and migration. This knowledge has the potential to improve decisions about biodiversity policy and management, but it can be difficult for decision makers to readily access and integrate the growing body of movement science. This is, in part, due to a lack of synthesis of information that is sufficiently contextualized for a policy audience. Here, we identify key species movement concepts, including mechanisms, types, and moderators of movement, and review their relevance to (1) national biodiversity policies and strategies, (2) reserve planning and management, (3) threatened species protection and recovery, (4) impact and risk assessments, and (5) the prioritization of restoration actions. Based on the review, and considering recent developments in movement ecology, we provide a new framework that draws links between aspects of movement knowledge that are likely the most relevant to each biodiversity policy category. Our framework also shows that there is substantial opportunity for collaboration between researchers and government decision makers in the use of movement science to promote positive biodiversity outcomes.

  19. Guidelines for Using Movement Science to Inform Biodiversity Policy.

    Science.gov (United States)

    Barton, Philip S; Lentini, Pia E; Alacs, Erika; Bau, Sana; Buckley, Yvonne M; Burns, Emma L; Driscoll, Don A; Guja, Lydia K; Kujala, Heini; Lahoz-Monfort, José J; Mortelliti, Alessio; Nathan, Ran; Rowe, Ross; Smith, Annabel L

    2015-10-01

    Substantial advances have been made in our understanding of the movement of species, including processes such as dispersal and migration. This knowledge has the potential to improve decisions about biodiversity policy and management, but it can be difficult for decision makers to readily access and integrate the growing body of movement science. This is, in part, due to a lack of synthesis of information that is sufficiently contextualized for a policy audience. Here, we identify key species movement concepts, including mechanisms, types, and moderators of movement, and review their relevance to (1) national biodiversity policies and strategies, (2) reserve planning and management, (3) threatened species protection and recovery, (4) impact and risk assessments, and (5) the prioritization of restoration actions. Based on the review, and considering recent developments in movement ecology, we provide a new framework that draws links between aspects of movement knowledge that are likely the most relevant to each biodiversity policy category. Our framework also shows that there is substantial opportunity for collaboration between researchers and government decision makers in the use of movement science to promote positive biodiversity outcomes.

  20. Going through the motions: incorporating movement analyses into disease research.

    Science.gov (United States)

    Dougherty, Eric R; Seidel, Dana P; Carlson, Colin J; Spiegel, Orr; Getz, Wayne M

    2018-04-01

    Though epidemiology dates back to the 1700s, most mathematical representations of epidemics still use transmission rates averaged at the population scale, especially for wildlife diseases. In simplifying the contact process, we ignore the heterogeneities in host movements that complicate the real world, and overlook their impact on spatiotemporal patterns of disease burden. Movement ecology offers a set of tools that help unpack the transmission process, letting researchers more accurately model how animals within a population interact and spread pathogens. Analytical techniques from this growing field can also help expose the reverse process: how infection impacts movement behaviours, and therefore other ecological processes like feeding, reproduction, and dispersal. Here, we synthesise the contributions of movement ecology in disease research, with a particular focus on studies that have successfully used movement-based methods to quantify individual heterogeneity in exposure and transmission risk. Throughout, we highlight the rapid growth of both disease and movement ecology and comment on promising but unexplored avenues for research at their overlap. Ultimately, we suggest, including movement empowers ecologists to pose new questions, expanding our understanding of host-pathogen dynamics and improving our predictive capacity for wildlife and even human diseases. © 2018 John Wiley & Sons Ltd/CNRS.

  1. [Neuropsychiatry Of Movement Disorders].

    Science.gov (United States)

    Orjuela-Rojas, Juan Manuel; Barrios Vincos, Gustavo Adolfo; Martínez Gallego, Melisa Alejandra

    2017-10-01

    Movement disorders can be defined as neurological syndromes presenting with excessive or diminished automatic or voluntary movements not related to weakness or spasticity. Both Parkinson's disease (PD) and Huntington's disease (HD) are well-known examples of these syndromes. The high prevalence of comorbid psychiatric symptoms like depression, anxiety, obsessive-compulsive symptoms, hallucinations, delusions, impulsivity, sleep disorders, apathy and cognitive impairment mean that these conditions must be regarded as neuropsychiatric diseases. In this article, we review neuroanatomical (structural and functional), psychopathological and neuropsychological aspects of PD and HD. The role of fronto-subcortical loops in non-motor functions is particularly emphasised in order to understand the clinical spectrum of both diseases, together with the influence of genetic, psychological and psychosocial aspects. A brief description of the main psychopharmacological approaches for both diseases is also included. Copyright © 2017 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

  2. Metapopulation extinction risk: dispersal's duplicity.

    Science.gov (United States)

    Higgins, Kevin

    2009-09-01

    Metapopulation extinction risk is the probability that all local populations are simultaneously extinct during a fixed time frame. Dispersal may reduce a metapopulation's extinction risk by raising its average per-capita growth rate. By contrast, dispersal may raise a metapopulation's extinction risk by reducing its average population density. Which effect prevails is controlled by habitat fragmentation. Dispersal in mildly fragmented habitat reduces a metapopulation's extinction risk by raising its average per-capita growth rate without causing any appreciable drop in its average population density. By contrast, dispersal in severely fragmented habitat raises a metapopulation's extinction risk because the rise in its average per-capita growth rate is more than offset by the decline in its average population density. The metapopulation model used here shows several other interesting phenomena. Dispersal in sufficiently fragmented habitat reduces a metapopulation's extinction risk to that of a constant environment. Dispersal between habitat fragments reduces a metapopulation's extinction risk insofar as local environments are asynchronous. Grouped dispersal raises the effective habitat fragmentation level. Dispersal search barriers raise metapopulation extinction risk. Nonuniform dispersal may reduce the effective fraction of suitable habitat fragments below the extinction threshold. Nonuniform dispersal may make demographic stochasticity a more potent metapopulation extinction force than environmental stochasticity.

  3. Monitoring underground movements

    CERN Multimedia

    Antonella Del Rosso

    2015-01-01

    On 16 September 2015 at 22:54:33 (UTC), an 8.3-magnitude earthquake struck off the coast of Chile. 11,650 km away, at CERN, a new-generation instrument – the Precision Laser Inclinometer (PLI) – recorded the extreme event. The PLI is being tested by a JINR/CERN/ATLAS team to measure the movements of underground structures and detectors.   The Precision Laser Inclinometer during assembly. The instrument has proven very accurate when taking measurements of the movements of underground structures at CERN.    The Precision Laser Inclinometer is an extremely sensitive device capable of monitoring ground angular oscillations in a frequency range of 0.001-1 Hz with a precision of 10-10 rad/Hz1/2. The instrument is currently installed in one of the old ISR transfer tunnels (TT1) built in 1970. However, its final destination could be the ATLAS cavern, where it would measure and monitor the fine movements of the underground structures, which can affect the precise posi...

  4. Anti-nuclear movements

    International Nuclear Information System (INIS)

    Ruedig, W.

    1990-01-01

    Nuclear power, heralded in the years after World War II as the answer to the world's energy needs, has in more recent times become the focus of intense ecological, political and economic debate. In this study, the current worldwide opposition to nuclear power is examined from its origins in expert dissent to the widespread development of grassroots activity. Chapter headings include: Social Movements: A Theoretical Framework; Creating the Preconditions for Public Protest; Local and Regional Opposition: Mobilizing the Grass Roots; Local Opposition and the Politicization of Nuclear Power; The Use of Local Opposition as a Political Resource; Local Opposition and Social Movement Analysis; The Removal of Political Stimuli: The Unpolitics of Nuclear Siting; Analyzing Host Community Attitudes: The Survey Evidence; Attitudes and Political Action of Nuclear Host Communities: Approaches and Explanations; Novel Siting Approaches and their Political Implications; Siting and Social Movement Analysis; Patterns and Outcomes of Nuclear Energy Conflicts; The Future of the Nuclear Energy Conflict. Throughout the text, analysis and theory are blended with detailed accounts of the growth and activities of individual anti-nuclear organizations in different countries. (author)

  5. Modeling emerald ash borer dispersal using percolation theory: estimating the rate of range expansion in a fragmented landscape

    Science.gov (United States)

    Robin A. J. Taylor; Daniel A. Herms; Louis R. Iverson

    2008-01-01

    The dispersal of organisms is rarely random, although diffusion processes can be useful models for movement in approximately homogeneous environments. However, the environments through which all organisms disperse are far from uniform at all scales. The emerald ash borer (EAB), Agrilus planipennis, is obligate on ash (Fraxinus spp...

  6. Sleep-related movement disorders.

    Science.gov (United States)

    Merlino, Giovanni; Gigli, Gian Luigi

    2012-06-01

    Several movement disorders may occur during nocturnal rest disrupting sleep. A part of these complaints is characterized by relatively simple, non-purposeful and usually stereotyped movements. The last version of the International Classification of Sleep Disorders includes these clinical conditions (i.e. restless legs syndrome, periodic limb movement disorder, sleep-related leg cramps, sleep-related bruxism and sleep-related rhythmic movement disorder) under the category entitled sleep-related movement disorders. Moreover, apparently physiological movements (e.g. alternating leg muscle activation and excessive hypnic fragmentary myoclonus) can show a high frequency and severity impairing sleep quality. Clinical and, in specific cases, neurophysiological assessments are required to detect the presence of nocturnal movement complaints. Patients reporting poor sleep due to these abnormal movements should undergo non-pharmacological or pharmacological treatments.

  7. Relativistic plasma dispersion functions

    International Nuclear Information System (INIS)

    Robinson, P.A.

    1986-01-01

    The known properties of plasma dispersion functions (PDF's) for waves in weakly relativistic, magnetized, thermal plasmas are reviewed and a large number of new results are presented. The PDF's required for the description of waves with small wave number perpendicular to the magnetic field (Dnestrovskii and Shkarofsky functions) are considered in detail; these functions also arise in certain quantum electrodynamical calculations involving strongly magnetized plasmas. Series, asymptotic series, recursion relations, integral forms, derivatives, differential equations, and approximations for these functions are discussed as are their analytic properties and connections with standard transcendental functions. In addition a more general class of PDF's relevant to waves of arbitrary perpendicular wave number is introduced and a range of properties of these functions are derived

  8. Social Movements and Institutions

    Directory of Open Access Journals (Sweden)

    Maria Francisca Pinheiro Coelho

    2017-04-01

    Full Text Available Abstract This study approaches the relationship between social movements and institutions in Brazil concerning three different stages of the process of re-democratization: the political transition; the National Constituent Assembly; and the new Constitutional Order. The general question is: what is the interface, reciprocity or conflict, between social movements and institutions in this context of social change? The paper examines the different roles of social movements and institutions in each specific period: in the pre-democratization moment, the movement for direct elections for president, Diretas-Já, is analyzed; in the National Constituent Assembly, the movement in defense for free public education is examined;  in the new constitutional order, the pro-reform political movement is studied.  The work focuses on the scope of the studies on social movements and democracy.  It belongs to the field of the studies about the representativeness and legitimacy of the demands of social movements in the context of democracy and its challenges. Key words: social movement, institution, reciprocity, conflict, democracy.   Social Movements and Institutions                               Resumen El estudio aborda la relación entre los movimientos sociales e instituciones en Brasil en tres etapas diferentes del proceso de redemocratización en las últimas décadas: la transición política; la Asamblea Nacional Constituyente; y el nuevo orden constitucional. La pregunta general es: ¿cuál es la relación, la reciprocidad o el conflito, entre los movimientos sociales y las instituciones en este contexto de cambio social? El artículo examina los diferentes roles de los movimientos sociales e instituciones en cada período específico: en el momento de la transición política analiza el movimiento de las elecciones directas para presidente, las Diretas-Já; en la Asamblea Nacional Constituyente aborda el movimiento en

  9. Human preference for air movement

    DEFF Research Database (Denmark)

    Toftum, Jørn; Melikov, Arsen Krikor; Tynel, A.

    2002-01-01

    Human preference for air movement was studied at slightly cool, neutral, and slightly warm overall thermal sensations and at temperatures ranging from 18 deg.C to 28 deg.C. Air movement preference depended on both thermal sensation and temperature, but large inter-individual differences existed...... between subjects. Preference for less air movement was linearly correlated with draught discomfort, but the percentage of subjects who felt draught was lower than the percentage who preferred less air movement....

  10. Philopatry and dispersal patterns in tiger (Panthera tigris.

    Directory of Open Access Journals (Sweden)

    Digpal Singh Gour

    Full Text Available Tiger populations are dwindling rapidly making it increasingly difficult to study their dispersal and mating behaviour in the wild, more so tiger being a secretive and solitary carnivore.We used non-invasively obtained genetic data to establish the presence of 28 tigers, 22 females and 6 males, within the core area of Pench tiger reserve, Madhya Pradesh. This data was evaluated along with spatial autocorrelation and relatedness analyses to understand patterns of dispersal and philopatry in tigers within this well-managed and healthy tiger habitat in India.We established male-biased dispersal and female philopatry in tigers and reiterated this finding with multiple analyses. Females show positive correlation up to 7 kms (which corresponds to an area of approximately 160 km(2 however this correlation is significantly positive only upto 4 kms, or 50 km(2 (r  = 0.129, p<0.0125. Males do not exhibit any significant correlation in any of the distance classes within the forest (upto 300 km(2. We also show evidence of female dispersal upto 26 kms in this landscape.Animal movements are important for fitness, reproductive success, genetic diversity and gene exchange among populations. In light of the current endangered status of tigers in the world, this study will help us understand tiger behavior and movement. Our findings also have important implications for better management of habitats and interconnecting corridors to save this charismatic species.

  11. Segmenting Trajectories by Movement States

    NARCIS (Netherlands)

    Buchin, M.; Kruckenberg, H.; Kölzsch, A.; Timpf, S.; Laube, P.

    2013-01-01

    Dividing movement trajectories according to different movement states of animals has become a challenge in movement ecology, as well as in algorithm development. In this study, we revisit and extend a framework for trajectory segmentation based on spatio-temporal criteria for this purpose. We adapt

  12. FUNdamental Movement in Early Childhood.

    Science.gov (United States)

    Campbell, Linley

    2001-01-01

    Noting that the development of fundamental movement skills is basic to children's motor development, this booklet provides a guide for early childhood educators in planning movement experiences for children between 4 and 8 years. The booklet introduces a wide variety of appropriate practices to promote movement skill acquisition and increased…

  13. Investigation of influence of drying agent movement on the drying process effectiveness in the gravitational shelf dryer

    Directory of Open Access Journals (Sweden)

    N. O. Artyukhova

    2017-12-01

    Full Text Available The article stands for a research of the drying process efficiency of various approaches of reciprocal movement organization of drying agent and disperse material. It focuses on the results of shelf dryer investigation. The test condition was as follows: backflow of the drying agent and disperse material movement; backflow of the drying agent and disperse material movement with the drying agent recirculation; backflow of the drying agent and disperse material movement with the bypassing of drying agent and it’s putting on separate stage of gravitational shelf dryer. The influence of the drying agent movement organization on the characteristics of disperse material and drying agent, energy costs for this process and its efficiency is shown. The recommendations of usage of represented approaches of flows movement organization depending on the desired final moisture of the material as well as its physical and chemical properties are given. The proposed ways of reciprocal flows movement organization allow to reduce the costs of drying agent heating or to increase the efficiency of moisture removal at constant energy consumption.

  14. Short-range movement of major agricultural pests

    Science.gov (United States)

    Vansteenwyk, R.

    1979-01-01

    Visual observations of population fluctuations which cannot be accounted for by either mortality or natality are presented. Lygus bugs in the westside of the San Joaquin Valley of California are used as an example. The dispersal of most agricultural pests in one of the less known facets of their biology is discussed. Results indicate a better understanding of insect movement is needed to develop a sound pest management program.

  15. Statistical Thermodynamics of Disperse Systems

    DEFF Research Database (Denmark)

    Shapiro, Alexander

    1996-01-01

    Principles of statistical physics are applied for the description of thermodynamic equilibrium in disperse systems. The cells of disperse systems are shown to possess a number of non-standard thermodynamic parameters. A random distribution of these parameters in the system is determined....... On the basis of this distribution, it is established that the disperse system has an additional degree of freedom called the macro-entropy. A large set of bounded ideal disperse systems allows exact evaluation of thermodynamic characteristics. The theory developed is applied to the description of equilibrium...

  16. Geometry of physical dispersion relations

    International Nuclear Information System (INIS)

    Raetzel, Dennis; Rivera, Sergio; Schuller, Frederic P.

    2011-01-01

    To serve as a dispersion relation, a cotangent bundle function must satisfy three simple algebraic properties. These conditions are derived from the inescapable physical requirements that local matter field dynamics must be predictive and allow for an observer-independent notion of positive energy. Possible modifications of the standard relativistic dispersion relation are thereby severely restricted. For instance, the dispersion relations associated with popular deformations of Maxwell theory by Gambini-Pullin or Myers-Pospelov are not admissible. Dispersion relations passing the simple algebraic checks derived here correspond to physically admissible Finslerian refinements of Lorentzian geometry.

  17. Habitat fragmentation impacts mobility in a common and widespread woodland butterfly: do sexes respond differently?

    Directory of Open Access Journals (Sweden)

    Bergerot Benjamin

    2012-04-01

    Full Text Available Abstract Background Theory predicts a nonlinear response of dispersal evolution to habitat fragmentation. First, dispersal will be favoured in line with both decreasing area of habitat patches and increasing inter-patch distances. Next, once these inter-patch distances exceed a critical threshold, dispersal will be counter-selected, unless essential resources no longer co-occur in compact patches but are differently scattered; colonization of empty habitat patches or rescue of declining populations are then increasingly overruled by dispersal costs like mortality risks and loss of time and energy. However, to date, most empirical studies mainly document an increase of dispersal associated with habitat fragmentation. We analyzed dispersal kernels for males and females of the common, widespread woodland butterfly Pararge aegeria in highly fragmented landscape, and for males in landscapes that differed in their degree of habitat fragmentation. Results The male and female probabilities of moving were considerably lower in the highly fragmented landscapes compared to the male probability of moving in fragmented agricultural and deciduous oak woodland landscapes. We also investigated whether, and to what extent, daily dispersal distance in the highly fragmented landscape was influenced by a set of landscape variables for both males and females, including distance to the nearest woodland, area of the nearest woodland, patch area and abundance of individuals in the patch. We found that daily movement distance decreased with increasing distance to the nearest woodland in both males and females. Daily distances flown by males were related to the area of the woodland capture site, whereas no such effect was observed for females. Conclusion Overall, mobility was strongly reduced in the highly fragmented landscape, and varied considerably among landscapes with different spatial resource distributions. We interpret the results relative to different cost

  18. Mate-finding as an overlooked critical determinant of dispersal variation in sexually-reproducing animals.

    Science.gov (United States)

    Gilroy, James J; Lockwood, Julie L

    2012-01-01

    Dispersal is a critically important process in ecology, but robust predictive models of animal dispersal remain elusive. We identify a potentially ubiquitous component of variation in animal dispersal that has been largely overlooked until now: the influence of mate encounters on settlement probability. We use an individual-based model to simulate dispersal in sexually-reproducing organisms that follow a simple set of movement rules based on conspecific encounters, within an environment lacking spatial habitat heterogeneity. We show that dispersal distances vary dramatically with fluctuations in population density in such a model, even in the absence of variation in dispersive traits between individuals. In a simple random-walk model with promiscuous mating, dispersal distributions become increasingly 'fat-tailed' at low population densities due to the increasing scarcity of mates. Similar variation arises in models incorporating territoriality. In a model with polygynous mating, we show that patterns of sex-biased dispersal can even be reversed across a gradient of population density, despite underlying dispersal mechanisms remaining unchanged. We show that some widespread dispersal patterns found in nature (e.g. fat tailed distributions) can arise as a result of demographic variability in the absence of heterogeneity in dispersive traits across the population. This implies that models in which individual dispersal distances are considered to be fixed traits might be unrealistic, as dispersal distances vary widely under a single dispersal mechanism when settlement is influenced by mate encounters. Mechanistic models offer a promising means of advancing our understanding of dispersal in sexually-reproducing organisms.

  19. Dispersion bias, dispersion effect, and the aerosol-cloud conundrum

    International Nuclear Information System (INIS)

    Liu Yangang; Daum, Peter H; Guo Huan; Peng Yiran

    2008-01-01

    This work examines the influences of relative dispersion (the ratio of the standard deviation to the mean radius of the cloud droplet size distribution) on cloud albedo and cloud radiative forcing, derives an analytical formulation that accounts explicitly for the contribution from droplet concentration and relative dispersion, and presents a new approach to parameterize relative dispersion in climate models. It is shown that inadequate representation of relative dispersion in climate models leads to an overestimation of cloud albedo, resulting in a negative bias of global mean shortwave cloud radiative forcing that can be comparable to the warming caused by doubling CO 2 in magnitude, and that this dispersion bias is likely near its maximum for ambient clouds. Relative dispersion is empirically expressed as a function of the quotient between cloud liquid water content and droplet concentration (i.e., water per droplet), yielding an analytical formulation for the first aerosol indirect effect. Further analysis of the new expression reveals that the dispersion effect not only offsets the cooling from the Twomey effect, but is also proportional to the Twomey effect in magnitude. These results suggest that unrealistic representation of relative dispersion in cloud parameterization in general, and evaluation of aerosol indirect effects in particular, is at least in part responsible for several outstanding puzzles of the aerosol-cloud conundrum: for example, overestimation of cloud radiative cooling by climate models compared to satellite observations; large uncertainty and discrepancy in estimates of the aerosol indirect effect; and the lack of interhemispheric difference in cloud albedo.

  20. Normal movement selectivity in autism.

    Science.gov (United States)

    Dinstein, Ilan; Thomas, Cibu; Humphreys, Kate; Minshew, Nancy; Behrmann, Marlene; Heeger, David J

    2010-05-13

    It has been proposed that individuals with autism have difficulties understanding the goals and intentions of others because of a fundamental dysfunction in the mirror neuron system. Here, however, we show that individuals with autism exhibited not only normal fMRI responses in mirror system areas during observation and execution of hand movements but also exhibited typical movement-selective adaptation (repetition suppression) when observing or executing the same movement repeatedly. Movement selectivity is a defining characteristic of neurons involved in movement perception, including mirror neurons, and, as such, these findings argue against a mirror system dysfunction in autism. Copyright 2010 Elsevier Inc. All rights reserved.

  1. Stereotypic movement disorders.

    Science.gov (United States)

    Singer, Harvey S

    2011-01-01

    Stereotypic movements are repetitive, rhythmic, fixed, patterned in form, amplitude, and localization, but purposeless (e.g., hand shaking, waving, body rocking, head nodding). They are commonly seen in children; both in normal children (primary stereotypy) and in individuals with additional behavioral or neurological signs and symptoms (secondary stereotypy). They should be differentiated from compulsions (OCD), tics (tic disorders), trichotillomania, skin picking disorder, or the direct physiological effect of a substance. There is increasing evidence to support a neurobiological mechanism. Response to behavioral and pharmacological therapies is variable. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. The tactile movement aftereffect.

    Science.gov (United States)

    Hollins, M; Favorov, O

    1994-01-01

    The existence of a tactile movement aftereffect was established in a series of experiments on the palmar surface of the hand and fingers of psychophysical observers. During adaptation, observers cupped their hand around a moving drum for up to 3 min; following this period of stimulation, they typically reported an aftereffect consisting of movement sensations located on and deep to the skin, and lasting for up to 1 min. Preliminary experiments comparing a number of stimulus materials mounted on the drum demonstrated that a surface approximating a low-spatial-frequency square wave, with a smooth microtexture, was especially effective at inducing the aftereffect; this adapting stimulus was therefore used throughout the two main experiments. In Experiment 1, the vividness of the aftereffect produced by 2 min of adaptation was determined under three test conditions: with the hand (1) remaining on the now stationary drum; (2) in contact with a soft, textured surface; or (3) suspended in air. Subjects' free magnitude estimates of the peak vividness of the aftereffect were not significantly different across conditions; each subject experienced the aftereffect at least once under each condition. Thus the tactile movement aftereffect does not seem to depend critically on the ponditions of stimulation that obtain while it is being experienced. In Experiment 2, the vividness and duration of the aftereffect were measured as a function of the duration of the adapting stimulus. Both measures increased steadily over the range of durations explored (30-180 sec). In its dependence on adapting duration, the aftereffect resembles the waterfall illusion in vision. An explanation for the tactile movement aftereffect is proposed, based on the model of cortical dynamics of Whitsel et al. (1989, 1991). With assumed modest variation of one parameter across individuals, this application of the model is able to account both for the data of the majority of subjects, who experienced the

  3. Fetal body movement monitoring.

    Science.gov (United States)

    Rayburn, W F

    1990-03-01

    Recording fetal activity serves as an indirect measure of central nervous system integrity and function. The coordination of whole body movement, which requires complex neurologic control, is likely similar to that of the newborn infant. Short-term observations of the fetus are best performed using real-time ultrasound imaging. Monitoring fetal motion has been shown to be clinically worthwhile in predicting impending death or compromise, especially when placental insufficiency is longstanding. The presence of a vigorous fetus is reassuring. Perceived inactivity requires a reassessment of any underlying antepartum complication and a more precise evaluation by fetal heart rate testing or real-time ultrasonography before delivery is contemplated.

  4. West African Antislavery Movements

    DEFF Research Database (Denmark)

    Hahonou, Eric Komlavi; Pelckmans, Lotte

    2011-01-01

    In the context of liberalization of West African political regimes, the upsurge of audacious political entrepreneurs who want to end chattel slavery in their nation-state, resulted in the legal criminalisation of slavery in both Mauritania (2007) and Niger (2003) and in a proposal to revise......-slavery movements had raised awareness, this political emergence was even easier. Indeed the fight against ‘slave mentalities’ was everywhere a major challenge and a crucial step to mobilize groups of slave status under a united force. As this article argues changes in political structures and changes in political...

  5. Modelling group dynamic animal movement

    DEFF Research Database (Denmark)

    Langrock, Roland; Hopcraft, J. Grant C.; Blackwell, Paul G.

    2014-01-01

    makes its movement decisions relative to the group centroid. The basic idea is framed within the flexible class of hidden Markov models, extending previous work on modelling animal movement by means of multi-state random walks. While in simulation experiments parameter estimators exhibit some bias......, to date, practical statistical methods which can include group dynamics in animal movement models have been lacking. We consider a flexible modelling framework that distinguishes a group-level model, describing the movement of the group's centre, and an individual-level model, such that each individual......Group dynamic movement is a fundamental aspect of many species' movements. The need to adequately model individuals' interactions with other group members has been recognised, particularly in order to differentiate the role of social forces in individual movement from environmental factors. However...

  6. Camera Movement in Narrative Cinema

    DEFF Research Database (Denmark)

    Nielsen, Jakob Isak

    2007-01-01

    section unearths what characterizes the literature on camera movement. The second section of the dissertation delineates the history of camera movement itself within narrative cinema. Several organizational principles subtending the on-screen effect of camera movement are revealed in section two...... but they are not organized into a coherent framework. This is the task that section three meets in proposing a functional taxonomy for camera movement in narrative cinema. Two presumptions subtend the taxonomy: That camera movement actively contributes to the way in which we understand the sound and images on the screen......, commentative or valuative manner. 4) Focalization: associating the movement of the camera with the viewpoints of characters or entities in the story world. 5) Reflexive: inviting spectators to engage with the artifice of camera movement. 6) Abstract: visualizing abstract ideas and concepts. In order...

  7. Animal movement in the absence of predation: environmental drivers of movement strategies in a partial migration system

    Science.gov (United States)

    Bastille-Rousseau, Guillaume; Gibbs, James P.; Yackulic, Charles B.; Frair, Jacqueline L.; Cabrera, Fredy; Rousseau, Louis-Philippe

    2016-01-01

    Animal movement strategies including migration, dispersal, nomadism, and residency are shaped by broad-scale spatial-temporal structuring of the environment, including factors such as the degrees of spatial variation, seasonality and inter-annual predictability. Animal movement strategies, in turn, interact with the characteristics of individuals and the local distribution of resources to determine local patterns of resource selection with complex and poorly understood implications for animal fitness. Here we present a multi-scale investigation of animal movement strategies and resource selection. We consider the degree to which spatial variation, seasonality, and inter-annual predictability in resources drive migration patterns among different taxa and how movement strategies in turn shape local resource selection patterns. We focus on adult Galapagos giant tortoises Chelonoidis spp. as a model system since they display many movement strategies and evolved in the absence of predators of adults. Specifically, our analysis is based on 63 individuals among four taxa tracked on three islands over six years and almost 106 tortoise re-locations. Tortoises displayed a continuum of movement strategies from migration to sedentarism that were linked to the spatio-temporal scale and predictability of resource distributions. Movement strategies shaped patterns of resource selection. Specifically, migratory individuals displayed stronger selection toward areas where resources were more predictable among years than did non-migratory individuals, which indicates a selective advantage for migrants in seasonally structured, more predictable environments. Our analytical framework combines large-scale predictions for movement strategies, based on environmental structuring, with finer-scale analysis of space-use. Integrating different organizational levels of analysis provides a deeper understanding of the eco-evolutionary dynamics at play in the emergence and maintenance of

  8. High dispersal in a frog species suggests that it is vulnerable to habitat fragmentation

    OpenAIRE

    Funk, W. Chris; Greene, Allison E; Corn, Paul Stephen; Allendorf, Fred W

    2005-01-01

    Global losses of amphibian populations are a major conservation concern and their causes have generated substantial debate. Habitat fragmentation is considered one important cause of amphibian decline. However, if fragmentation is to be invoked as a mechanism of amphibian decline, it must first be established that dispersal is prevalent among contiguous amphibian populations using formal movement estimators. In contrast, if dispersal is naturally low in amphibians, fragmentation can be disreg...

  9. Auroral electron time dispersion

    International Nuclear Information System (INIS)

    Kletzing, C.A.

    1989-01-01

    A sounding rocket flight was launched from Greenland in 1985 to study high latitude, early morning auroral physics. The payload was instrumented with electron and ion detectors, AC and DC electric field experiments, a plasma density experiment, and a magnetometer to measure the ambient field. The rocket was launched during disturbed conditions, when the polar cap was in a contracted state with visible aurora overhead. The electron data contained numerous signatures indicative of time-of-flight energy dispersion characterized by a coherent structure in which lower energy electrons arrived at the rocket after higher energy electrons. A model was constructed to explain this phenomena by the sudden application of a region of parallel electric field along a length of magnetic field line above the rocket. The model incorporates detector response and uses an altitudinal density profile based on auroral zone measurements. Three types of potential structures were tried: linear, quadratic and cubic. Of the three it was found that the cubic (electric field growing in a quadratic manner moving up the field line) produced the best fit to the data. The potential region was found to be approximately 1-2 R e in extent with the lower edge 3000-4000 km away from the rocket. The background electron temperature in the model which produced the best fit to the data was of the order of 15 eV

  10. Progress in urban dispersion studies

    DEFF Research Database (Denmark)

    Batchvarova, E.; Gryning, Sven-Erik

    2006-01-01

    The present Study addresses recent achievements in better representation Of the urban area structure in meteorology and dispersion parameterisations. The setup and Main Outcome of several recent dispersion experiments in Urban areas and their use in model validation are discussed. The maximum con...

  11. Nest-mediated seed dispersal

    Science.gov (United States)

    Robert J. Warren; Jason P. Love; Mark A. Bradford

    2017-01-01

    Many plant seeds travel on the wind and through animal ingestion or adhesion; however, an overlooked dispersal mode may lurk within those dispersal modes. Viable seeds may remain attached or embedded within materials birds gather for nest building. Our objective was to determine if birds inadvertently transport seeds when they forage for plant materials to...

  12. Definition of global dispersion coefficients

    International Nuclear Information System (INIS)

    Naff, R.L.

    1983-10-01

    For estimation of a global longitudinal dispersivity at the Gorleben site, data available primarily consist of suites of geophysical logs from wells penetrating the Quaternary aquifer. A length scale for the principle aquifer at Gorleben is to be found. Samples are to be taken separately to estimate the variance in hydraulic conductivity (Taylor Analysis, Fickian dispersion process). (DG)

  13. How do dispersal costs and habitat selection influence realized population connectivity?

    Science.gov (United States)

    Burgess, Scott C; Treml, Eric A; Marshall, Dustin J

    2012-06-01

    Despite the importance of dispersal for population connectivity, dispersal is often costly to the individual. A major impediment to understanding connectivity has been a lack of data combining the movement of individuals and their survival to reproduction in the new habitat (realized connectivity). Although mortality often occurs during dispersal (an immediate cost), in many organisms costs are paid after dispersal (deferred costs). It is unclear how such deferred costs influence the mismatch between dispersal and realized connectivity. Through a series of experiments in the field and laboratory, we estimated both direct and indirect deferred costs in a marine bryozoan (Bugula neritina). We then used the empirical data to parameterize a theoretical model in order to formalize predictions about how dispersal costs influence realized connectivity. Individuals were more likely to colonize poor-quality habitat after prolonged dispersal durations. Individuals that colonized poor-quality habitat performed poorly after colonization because of some property of the habitat (an indirect deferred cost) rather than from prolonged dispersal per se (a direct deferred cost). Our theoretical model predicted that indirect deferred costs could result in nonlinear mismatches between spatial patterns of potential and realized connectivity. The deferred costs of dispersal are likely to be crucial for determining how well patterns of dispersal reflect realized connectivity. Ignoring these deferred costs could lead to inaccurate predictions of spatial population dynamics.

  14. A critical review on the scaling theory of dispersion

    Science.gov (United States)

    Zech, Alraune; Mai, Juliane; Attinger, Sabine; Dietrich, Peter; Teutsch, Georg; Fiori, Aldo; Rubin, Yoram

    2014-05-01

    The phenomenon of dispersive mixing of solutes in aquifers is subject of research since decades. The characterization of dispersivity at a particular field site is a prerequisite to predict the movement and spreading of a contaminant plume. Experimental investigations have shown, that field-scale dispersivities vary over orders of magnitude, which apparently depends on the scale of measurement. Gelhar et al. [1992] and Schulze-Makuch [2005] have reviewed a large number of transport experiments reported in the literature. Based on that data Schulze-Makuch [2005] performed a trend analysis of longitudinal dispersivity, fostering the empirical relationship of a power law between dispersivities and the scale of measurement without an upper bound. The goal of our study is to critically revisit not only the data used for the trend analysis but the power-law scale dependence of longitudinal dispersivity (e.g. Neuman [1990], Xu and Eckstein [1995]). Our particular focus is on the reported dispersivities of large amount (larger than 100m) and large measurement scales (in the order of kilometers). We aim to evaluate current theories of transport against a critical "mass" of field experiments and to bracket the conditions of their applicability. We further aim to evaluate the adequacy of the field sampling techniques that were employed from the perspective of more than 30 years development in modeling and field characterization. Given the tremendous progress in field data acquisition techniques and new insights gained, it is reasonable to expect that interpretations of past experiments may be flawed due to the limitations or inadequacy of field sampling techniques. Gelhar, L.W., C. Welty, and K.R. Rehfeldt, 1992, A critical review of data on field-scale dispersion in aquifers, Water Resources Research 28, No. 7: 1955-1974. Schulze-Makuch, D., 2005, Longitudinal dispersivity data and implications for scaling behavior, Ground Water, Vol. 43, No. 3, 443-456. Neuman, S.P., 1990

  15. Territoriality, prospecting, and dispersal in cooperatively breeding Micronesian Kingfishers (Todiramphus cinnamominus reichenbachii)

    Science.gov (United States)

    Kesler, D.C.; Haig, S.M.

    2007-01-01

    We investigated territoriality, prospecting, and dispersal behavior in cooperatively breeding Pohnpei Micronesian Kingfishers (Todiramphus cinnamominus reichenbachii) throughout the annual cycle using radiotelemetry and color-band resights. Mean home-range size was 6.3 ha and territories were 8.1 ha. Within territories, Micronesian Kingfishers shared 63% of their home-range space with coterritorial occupants, and 3% was shared with extraterritorial conspecifics. Birds on cooperative territories had larger home ranges that overlapped more with coterritory occupants' home ranges than birds in pair-held territories. Despite evidence suggesting that resources necessary for survival and reproduction occurred on each territory, Micronesian Kingfishers of all age and sex classes made extraterritorial prospecting movements. Prospecting was rare; it comprised only 4.3% of our observations. When birds departed on forays, they were gone for ∼1.9 h and returned to home territories before sunset. Prospecting by dominant birds was temporally correlated with courtship and nest initiation, and birds were observed at neighboring nest sites with opposite-sex conspecifics during the period when females were available for fertilization. Juveniles and helpers prospected throughout the year and made repeated homesteading movements to dispersal destinations before dispersing. Mean dispersal distance for radiomarked individuals was 849 m. Results suggest that prospecting in Micronesian Kingfishers is a complex behavior that provides information for dispersal decisions and familiarity with dispersal destinations. Additionally, extraterritorial movements may provide covert opportunities for reproduction, which have potential to profoundly influence the distribution of fitness among helper and dominant Micronesian Kingfishers.

  16. Retention time variability as a mechanism for animal mediated long-distance dispersal.

    Directory of Open Access Journals (Sweden)

    Vishwesha Guttal

    Full Text Available Long-distance dispersal (LDD events, although rare for most plant species, can strongly influence population and community dynamics. Animals function as a key biotic vector of seeds and thus, a mechanistic and quantitative understanding of how individual animal behaviors scale to dispersal patterns at different spatial scales is a question of critical importance from both basic and applied perspectives. Using a diffusion-theory based analytical approach for a wide range of animal movement and seed transportation patterns, we show that the scale (a measure of local dispersal of the seed dispersal kernel increases with the organisms' rate of movement and mean seed retention time. We reveal that variations in seed retention time is a key determinant of various measures of LDD such as kurtosis (or shape of the kernel, thinkness of tails and the absolute number of seeds falling beyond a threshold distance. Using empirical data sets of frugivores, we illustrate the importance of variability in retention times for predicting the key disperser species that influence LDD. Our study makes testable predictions linking animal movement behaviors and gut retention times to dispersal patterns and, more generally, highlights the potential importance of animal behavioral variability for the LDD of seeds.

  17. Genetics Home Reference: congenital mirror movement disorder

    Science.gov (United States)

    ... Health Conditions Congenital mirror movement disorder Congenital mirror movement disorder Printable PDF Open All Close All Enable ... view the expand/collapse boxes. Description Congenital mirror movement disorder is a condition in which intentional movements ...

  18. Microbial modification of host long-distance dispersal capacity

    Directory of Open Access Journals (Sweden)

    Hutchings Linda

    2009-06-01

    Full Text Available Abstract Background Dispersal plays a key role in shaping biological and ecological processes such as the distribution of spatially-structured populations or the pace and scale of invasion. Here we have studied the relationship between long-distance dispersal behaviour of a pest-controlling money spider, Erigone atra, and the distribution of maternally acquired endosymbionts within the wider meta-population. This spider persists in heterogeneous environments because of its ability to recolonise areas through active long-distance airborne dispersal using silk as a sail, in a process termed 'ballooning'. Results We show that there is spatial heterogeneity in the prevalence of two maternally acquired endosymbiont infections within the wider E. atra meta-population and we demonstrate through several independent approaches a link between the presence of one of these endosymbionts, Rickettsia, and the tendency for long-distance movement. Conclusion This novel finding that particular endosymbionts can influence host dispersal is of broad importance given the extremely widespread occurrence of similar bacteria within arthropod communities. A bacterial phenotype that limits dispersal has the potential not only to reduce gene flow and thus contribute to degrees of reproductive isolation within species, but also to influence species distribution and thus overall community composition.

  19. Temporomandibular joint movement

    International Nuclear Information System (INIS)

    Maeda, M.; Itou, S.; Ishii, Y.; Yamamoto, K.; Kawamura, Y.; Matsuda, T.; Hayashi, N.; Ishii, J.

    1992-01-01

    Ten temporomandibular joints (TMJs) of 5 healthy volunteers and 19 TMJs of internal derangements in 16 patients with splint therapy were examined with MR imaging. T1-weighted images were obtained only in the closed mouth position, and gradient recalled acquisition in steady state (GRASS) images were obtained in active opening and closing phases, allowing a pseudodynamic display of TMJ movement. All patients received protrusive splint treatment. The usefulness of MR imaging to assess the efficacy of splint therapy was evaluated. Corrected disk position with the splint in place was clearly demonstrated in 9 TMJs, corresponding with elimination of reciprocal clicking. Ten other TMJs of anterior disk displacement without reduction showed uncorrected disk position by the splint. This information could confirm the therapeutic efficacy, or suggest other treatment alternatives. GRASS MR imaging can provide accurate and physiologic information about disk function in initial and follow-up assessment of protrusive splint therapy. (orig.)

  20. Tracking the Poster Movement

    DEFF Research Database (Denmark)

    Christensen, Line Hjorth

    2015-01-01

    Summary: This article considers the display of posters as a distinctive activity and defining aspect of British modernism between the two wars, looking to a cardinal event, the Exhibition of British and Foreign Posters at the Victoria and Albert Museum in 1931. This manifestation was the first...... in the Museum to expose the poster-image as a medium in its own artistic, technical, historical and popular right; the article examines the event as a sign holding core characteristics of a ‘poster movement’ prevailing during the interwar years. The period made a varied scene for exhibitions promoting...... commercial and graphic design of various kinds of which British and Foreign Posters offers a particularly rich example. The exhibition attracted commercial, artistic and curatorial forces substantiating the idea of a movement, and approached commercial art from a perspective that raised new awareness towards...

  1. The Circular Camera Movement

    DEFF Research Database (Denmark)

    Hansen, Lennard Højbjerg

    2014-01-01

    It has been an accepted precept in film theory that specific stylistic features do not express specific content. Nevertheless, it is possible to find many examples in the history of film in which stylistic features do express specific content: for instance, the circular camera movement is used...... repeatedly to convey the feeling of a man and a woman falling in love. This raises the question of why producers and directors choose certain stylistic features to narrate certain categories of content. Through the analysis of several short film and TV clips, this article explores whether...... or not there are perceptual aspects related to specific stylistic features that enable them to be used for delimited narrational purposes. The article further attempts to reopen this particular stylistic debate by exploring the embodied aspects of visual perception in relation to specific stylistic features...

  2. Material and Affective Movements

    DEFF Research Database (Denmark)

    Rasmussen, Lisa Rosén

    2014-01-01

    . The chapter traces the former pupil’s memories of physical and affective movements within the larger context of school and discovers surprisingly diverse modes of knowing, relating, and attending to things, teachers and classmates among and between the three generations. It thus taps into the rich realms...... of individual experiences of school and everyday school life as it unfolds in and beyond the formal teaching situations. The chapter follows in the wake of a growing attention to the aspects of everyday life and lived life at school in the history of education. It also develops tools for and demonstrates how...... the use of spoken memories is a rewarding source for the writing about school from the pupils’ perspective....

  3. Landscape movements of Anopheles gambiae malaria vector mosquitoes in rural Gambia.

    Science.gov (United States)

    Thomas, Christopher J; Cross, Dónall E; Bøgh, Claus

    2013-01-01

    For malaria control in Africa it is crucial to characterise the dispersal of its most efficient vector, Anopheles gambiae, in order to target interventions and assess their impact spatially. Our study is, we believe, the first to present a statistical model of dispersal probability against distance from breeding habitat to human settlements for this important disease vector. We undertook post-hoc analyses of mosquito catches made in The Gambia to derive statistical dispersal functions for An. gambiae sensu lato collected in 48 villages at varying distances to alluvial larval habitat along the River Gambia. The proportion dispersing declined exponentially with distance, and we estimated that 90% of movements were within 1.7 km. Although a 'heavy-tailed' distribution is considered biologically more plausible due to active dispersal by mosquitoes seeking blood meals, there was no statistical basis for choosing it over a negative exponential distribution. Using a simple random walk model with daily survival and movements previously recorded in Burkina Faso, we were able to reproduce the dispersal probabilities observed in The Gambia. Our results provide an important quantification of the probability of An. gambiae s.l. dispersal in a rural African setting typical of many parts of the continent. However, dispersal will be landscape specific and in order to generalise to other spatial configurations of habitat and hosts it will be necessary to produce tractable models of mosquito movements for operational use. We show that simple random walk models have potential. Consequently, there is a pressing need for new empirical studies of An. gambiae survival and movements in different settings to drive this development.

  4. Clinical features of movement disorders.

    Science.gov (United States)

    Yung, C Y

    1983-08-01

    The descriptive aspects of all types of movement disorders and their related syndromes and terminologies used in the literature are reviewed and described. This comprises the features of (a) movement disorders secondary to neurological diseases affecting the extrapyramidal motor system, such as: athetosis, chorea, dystonia, hemiballismus, myoclonus, tremor, tics and spasm, (b) drug induced movement disorders, such as: akathisia, akinesia, hyperkinesia, dyskinesias, extrapyramidal syndrome, and tardive dyskinesia, and (c) abnormal movements in psychiatric disorders, such as: mannerism, stereotyped behaviour and psychomotor retardation. It is intended to bring about a more comprehensive overview of these movement disorders from a phenomenological perspective, so that clinicians can familiarize with these features for diagnosis. Some general statements are made in regard to some of the characteristics of movement disorders.

  5. Wave-equation dispersion inversion

    KAUST Repository

    Li, Jing

    2016-12-08

    We present the theory for wave-equation inversion of dispersion curves, where the misfit function is the sum of the squared differences between the wavenumbers along the predicted and observed dispersion curves. The dispersion curves are obtained from Rayleigh waves recorded by vertical-component geophones. Similar to wave-equation traveltime tomography, the complicated surface wave arrivals in traces are skeletonized as simpler data, namely the picked dispersion curves in the phase-velocity and frequency domains. Solutions to the elastic wave equation and an iterative optimization method are then used to invert these curves for 2-D or 3-D S-wave velocity models. This procedure, denoted as wave-equation dispersion inversion (WD), does not require the assumption of a layered model and is significantly less prone to the cycle-skipping problems of full waveform inversion. The synthetic and field data examples demonstrate that WD can approximately reconstruct the S-wave velocity distributions in laterally heterogeneous media if the dispersion curves can be identified and picked. The WD method is easily extended to anisotropic data and the inversion of dispersion curves associated with Love waves.

  6. Patterns of movement of radioactive carabid beetles

    International Nuclear Information System (INIS)

    Baars, M.A.

    1980-01-01

    Tracking of individual 192 Ir-labelled ground beetles released in the field revealed that both the day-active and night-active species studied showed periods of small distances covered per day in random directions, alternating with periods of directed movement with large distances covered per day. This pattern occurred not only in the reproductive period but outside the breeding season as well in juvenile Pterostichus versicolor and spent Calathus melanocephalus. Although mean locomotory activity increased with temperature, great daily differences occurred between individuals, pointing to asynchronous behaviour. In an unfavorable habitat directed movement occurred both more frequently and more extremely, sometimes resulting in escape to more favorable areas. Most of the radioactive beetles died within 7 weeks due to radiation effects, but independent field experiments and simulations showed that the recorded patterns were valid. Simulated individuals of P. versicolor living on 1 ha spread over 49 ha, whereas simulated C. melanocephalus covered only 9 ha after one activity season. Normal locomotory activities lead to both exchange of individuals between subpopulations and dispersal out of the habitat. The significance of these phenomena for population stability and for the survival of the species is discussed. (orig.) [de

  7. The importance of habitat resistance for movement decisions in the common lizard, Lacerta vivipara

    Directory of Open Access Journals (Sweden)

    Zajitschek Susanne RK

    2012-07-01

    Full Text Available Abstract Background Movement behaviour can be influenced by a multitude of biotic and abiotic factors. Here, we investigate the speed of movement in relation to environmental and individual phenotypic properties in subadult common lizards (Lacerta vivipara. We aim to disentangle the importance of substrate, cover, humidity, basking opportunity and individual phenotype on moving tendencies in 12 treatment combinations, at which each lizard was tested. Results We find that movement behaviour depends on the starting conditions, the physical properties of the dispersal corridor, and on the individuals’ phenotype. Specifically, the presence of cover and substrate providing suitable traction in the corridor had positive effects on individual movement decisions. Additionally, we find high phenotypic variation in the propensity to move dependent on the presence of cover. Individual back patterns also strongly affected movement decisions in interaction with the physical properties of the dispersal corridor. Conclusions Our results highlight the importance of understanding the habitat resistance for movement patterns, with humid habitats with covering vegetation providing the best conditions to initiate movement in the common lizard. In addition, population effects, differences in back pattern phenotype and individual plasticity were identified as key parameters influencing movement behaviour.

  8. Normal Movement Selectivity in Autism

    OpenAIRE

    Dinstein, Ilan; Thomas, Cibu; Humphreys, Kate; Minshew, Nancy; Behrmann, Marlene; Heeger, David J.

    2010-01-01

    It has been proposed that individuals with autism have difficulties understanding the goals and intentions of others because of a fundamental dysfunction in the mirror neuron system. Here, however, we show that individuals with autism exhibited not only normal fMRI responses in mirror system areas during observation and execution of hand movements, but also exhibited typical movement-selective adaptation (repetition suppression) when observing or executing the same movement repeatedly. Moveme...

  9. SAGE measurements of the stratospheric aerosol dispersion and loading from the Soufriere Volcano

    Science.gov (United States)

    Mccormick, M. P.; Kent, G. S.; Yue, G. K.; Cunnold, D. M.

    1981-01-01

    Explosions of the Soufriere volcano on the Caribbean Island of St. Vincent reduced two major stratospheric plumes which the stratospheric aerosol and gas experiment (SAGE) satellite tracked to West Africa and the North Atlantic Ocean. The total mass of the stratospheric ejecta measured is less than 0.5% of the global stratospheric aerosol burden. No significant temperature or climate perturbation is expected. It is found that the movement and dispersion of the plumes agree with those deduced from high altitude meteorological data and dispersion theory. The stratospheric aerosol dispersion and loading from the Soufrier volcano was measured.

  10. Dispersion Decay and Scattering Theory

    CERN Document Server

    Komech, Alexander

    2012-01-01

    A simplified, yet rigorous treatment of scattering theory methods and their applications Dispersion Decay and Scattering Theory provides thorough, easy-to-understand guidance on the application of scattering theory methods to modern problems in mathematics, quantum physics, and mathematical physics. Introducing spectral methods with applications to dispersion time-decay and scattering theory, this book presents, for the first time, the Agmon-Jensen-Kato spectral theory for the Schr?dinger equation, extending the theory to the Klein-Gordon equation. The dispersion decay plays a crucial role i

  11. Velocity Dispersions Across Bulge Types

    International Nuclear Information System (INIS)

    Fabricius, Maximilian; Bender, Ralf; Hopp, Ulrich; Saglia, Roberto; Drory, Niv; Fisher, David

    2010-01-01

    We present first results from a long-slit spectroscopic survey of bulge kinematics in local spiral galaxies. Our optical spectra were obtained at the Hobby-Eberly Telescope with the LRS spectrograph and have a velocity resolution of 45 km/s (σ*), which allows us to resolve the velocity dispersions in the bulge regions of most objects in our sample. We find that the velocity dispersion profiles in morphological classical bulge galaxies are always centrally peaked while the velocity dispersion of morphologically disk-like bulges stays relatively flat towards the center--once strongly barred galaxies are discarded.

  12. The Explanatory Range of Movement

    DEFF Research Database (Denmark)

    Thrane, Torben

    2005-01-01

    Drawing a distinction between systemic and functional explanations of movement in general, I shall argue that the Chomskyan view of movement in language is originally functional. With the advent of the Minimimalist Program, however, it has become systemic, but no argument for this change has been...... forthcoming. I'll then present data (from Danish) to sustain the view that only functional type explanations of movement can be empirically motivated, and these only if movement is reinterpreted as transition states between representations of different kinds....

  13. Bewitched - The Tea Party Movement

    DEFF Research Database (Denmark)

    Ashbee, Edward

    2011-01-01

    This article considers the development of the Tea Party movement, the character of its thinking and the nature of the interests and constituencies to which it is tied. The article suggests that despite the importance of ideas and interests, and the process of interaction between them, the movement....... The political friction that this creates has contributed to the anger that has characterised the movement. While the Tea Party movement may, as such, have only an ephemeral existence, independent conservatives are likely to remain a significant and potent constituency and will, within the institutional...

  14. Movement Matters: Observing the Benefits of Movement Practice

    Science.gov (United States)

    Fuchs, Melani Alexander

    2015-01-01

    Montessori's first premise is that movement and cognition are closely entwined, and movement can enhance thinking and learning (Lillard, 2005). Children must move, and practice moving, to develop strength, balance, and the stability needed to fully participate in the rigors of daily life. It is imperative for young children's motor…

  15. Social-movement analysis of the American antinuclear movement

    International Nuclear Information System (INIS)

    Ladd, A.E.

    1981-01-01

    Utilizing data from a survey of participants at the May 6, 1979 antinuclear rally in Washington, DC (N = 420), this dissertation explored some of the major structural and ideological characteristics of the American Antinuclear Movement. By organizing the data around three of the key analytical concepts in the study of social movements - mobilization, recruitment, and ideology - the author was able to derive from the demonstration sample a descriptive and illustrative analysis of those individuals, organizations, and processes involved in the national antinuclear crusade. Given that few researchers have actively studied the antinuclear movement beyond the scope of local or regional protests, this work constitutes the only empirical study to date examining a cross section of the movement's participants from a sociological perspective. It is also one of the few attempts to use a national demonstration as a social laboratory for the study of a social movement in general. In terms of the mobilization variables examined in the study, it was found that organizational networks, past movement activism, and individual resources were important factors in the May 6 mobilization effort. While less than one-half of the demonstrators were part of the antinuclear organizational network per se, most of them had been active in the major protest movements of the 1960's and 1970's. The demonstrators were relatively high in socio-economic resources and had occupational or educational schedules conducive to creating the necessary discretionary time for movement participation

  16. Fate of dispersed marine fuel oil in sediment under pre-spill application strategy

    International Nuclear Information System (INIS)

    Jian Hua

    2004-01-01

    A comparison of the movement of dispersed oil in marine sediment under two dispersant application scenarios, applied prior to and after oil being spilled overboard, was examined. The pre-spill application scenario caused much less oil to be retained in the top sediment than post-spill scenario. The difference in oil retention in the top sediment between pre- and post-spill application scenario increased with increase in fuel oil temperature. For fuel oil above 40 o C, the difference in the effect of pre-spill application strategy under various water temperatures was negligible. When soap water was used as replacement for chemical dispersant, almost one-half as much oil was retained in the top sediment as that when using chemical dispersant. The adsorption of dispersed oil to the top sediment was almost proportionally decreased with doubling of soap dosage. (Author)

  17. Use of multiple dispersal pathways facilitates amphibian persistence in stream networks

    Science.gov (United States)

    Campbell, Grant E.H.; Nichols, J.D.; Lowe, W.H.; Fagan, W.F.

    2010-01-01

    Although populations of amphibians are declining worldwide, there is no evidence that salamanders occupying small streams are experiencing enigmatic declines, and populations of these species seem stable. Theory predicts that dispersal through multiple pathways can stabilize populations, preventing extinction in habitat networks. However, empirical data to support this prediction are absent for most species, especially those at risk of decline. Our mark-recapture study of stream salamanders reveals both a strong upstream bias in dispersal and a surprisingly high rate of overland dispersal to adjacent headwater streams. This evidence of route-dependent variation in dispersal rates suggests a spatial mechanism for population stability in headwater-stream salamanders. Our results link the movement behavior of stream salamanders to network topology, and they underscore the importance of identifying and protecting critical dispersal pathways when addressing region-wide population declines.

  18. Use of multiple dispersal pathways facilitates amphibian persistence in stream networks.

    Science.gov (United States)

    Campbell Grant, Evan H; Nichols, James D; Lowe, Winsor H; Fagan, William F

    2010-04-13

    Although populations of amphibians are declining worldwide, there is no evidence that salamanders occupying small streams are experiencing enigmatic declines, and populations of these species seem stable. Theory predicts that dispersal through multiple pathways can stabilize populations, preventing extinction in habitat networks. However, empirical data to support this prediction are absent for most species, especially those at risk of decline. Our mark-recapture study of stream salamanders reveals both a strong upstream bias in dispersal and a surprisingly high rate of overland dispersal to adjacent headwater streams. This evidence of route-dependent variation in dispersal rates suggests a spatial mechanism for population stability in headwater-stream salamanders. Our results link the movement behavior of stream salamanders to network topology, and they underscore the importance of identifying and protecting critical dispersal pathways when addressing region-wide population declines.

  19. What Causes Animals to Disperse?

    Indian Academy of Sciences (India)

    research involving animal behaviour and ecology for a very long time. ... shall examine two different types of dispersals that occur, try to understand the ... finally look at some practical methods through which the phe- ..... further qualitative or.

  20. Birefringent dispersive FDTD subgridding scheme

    OpenAIRE

    De Deckere, B; Van Londersele, Arne; De Zutter, Daniël; Vande Ginste, Dries

    2016-01-01

    A novel 2D finite difference time domain (FDTD) subgridding method is proposed, only subject to the Courant limit of the coarse grid. By making mu or epsilon inside the subgrid dispersive, unconditional stability is induced at the cost of a sparse, implicit set of update equations. By only adding dispersion along preferential directions, it is possible to dramatically reduce the rank of the matrix equation that needs to be solved.

  1. Dispersion engineering for integrated nanophotonics

    CERN Document Server

    Vanbésien, Olivier

    2014-01-01

    This book shows how dispersion engineering in two dimensional dielectric photonic crystals can provide new effects for the precise control of light propagation for integrated nanophotonics.Dispersion engineering in regular and graded photonic crystals to promote anomalous refraction effects is studied from the concepts to experimental demonstration via nanofabrication considerations. Self collimation, ultra and negative refraction, second harmonic generation, mirage and invisibility effects which lead to an unprecedented control of light propagation at the (sub-)wavelength scale for the

  2. Dispersion coefficients for coastal regions

    International Nuclear Information System (INIS)

    MacRae, B.L.; Kaleel, R.J.; Shearer, D.L.

    1983-03-01

    The Nuclear Regulatory Commission (NRC) has undertaken an extensive atmospheric dispersion research and measurement program from which it is intended will emerge improved predictive techniques for employment in licensing decisions and for emergency planning and response. Through this program the NRC has conducted field measurement programs over a wide range of geographic and topographic locations, and are using the acquired tracer and meteorological measurements to evaluate existing dispersion models and prediction techniques, and to develop new techniques when necessary

  3. Dispersal similarly shapes both population genetics and community patterns in the marine realm

    KAUST Repository

    Chust, Guillem

    2016-06-27

    Dispersal plays a key role to connect populations and, if limited, is one of the main processes to maintain and generate regional biodiversity. According to neutral theories of molecular evolution and biodiversity, dispersal limitation of propagules and population stochasticity are integral to shaping both genetic and community structure. We conducted a parallel analysis of biological connectivity at genetic and community levels in marine groups with different dispersal traits. We compiled large data sets of population genetic structure (98 benthic macroinvertebrate and 35 planktonic species) and biogeographic data (2193 benthic macroinvertebrate and 734 planktonic species). We estimated dispersal distances from population genetic data (i.e., FST vs. geographic distance) and from β-diversity at the community level. Dispersal distances ranked the biological groups in the same order at both genetic and community levels, as predicted by organism dispersal ability and seascape connectivity: macrozoobenthic species without dispersing larvae, followed by macrozoobenthic species with dispersing larvae and plankton (phyto- and zooplankton). This ranking order is associated with constraints to the movement of macrozoobenthos within the seabed compared with the pelagic habitat. We showed that dispersal limitation similarly determines the connectivity degree of communities and populations, supporting the predictions of neutral theories in marine biodiversity patterns.

  4. Dispersal similarly shapes both population genetics and community patterns in the marine realm

    Science.gov (United States)

    Chust, Guillem; Villarino, Ernesto; Chenuil, Anne; Irigoien, Xabier; Bizsel, Nihayet; Bode, Antonio; Broms, Cecilie; Claus, Simon; Fernández de Puelles, María L.; Fonda-Umani, Serena; Hoarau, Galice; Mazzocchi, Maria G.; Mozetič, Patricija; Vandepitte, Leen; Veríssimo, Helena; Zervoudaki, Soultana; Borja, Angel

    2016-06-01

    Dispersal plays a key role to connect populations and, if limited, is one of the main processes to maintain and generate regional biodiversity. According to neutral theories of molecular evolution and biodiversity, dispersal limitation of propagules and population stochasticity are integral to shaping both genetic and community structure. We conducted a parallel analysis of biological connectivity at genetic and community levels in marine groups with different dispersal traits. We compiled large data sets of population genetic structure (98 benthic macroinvertebrate and 35 planktonic species) and biogeographic data (2193 benthic macroinvertebrate and 734 planktonic species). We estimated dispersal distances from population genetic data (i.e., FST vs. geographic distance) and from β-diversity at the community level. Dispersal distances ranked the biological groups in the same order at both genetic and community levels, as predicted by organism dispersal ability and seascape connectivity: macrozoobenthic species without dispersing larvae, followed by macrozoobenthic species with dispersing larvae and plankton (phyto- and zooplankton). This ranking order is associated with constraints to the movement of macrozoobenthos within the seabed compared with the pelagic habitat. We showed that dispersal limitation similarly determines the connectivity degree of communities and populations, supporting the predictions of neutral theories in marine biodiversity patterns.

  5. Dispersal similarly shapes both population genetics and community patterns in the marine realm

    KAUST Repository

    Chust, Guillem; Villarino, Ernesto; Chenuil, Anne; Irigoien, Xabier; Bizsel, Nihayet; Bode, Antonio; Broms, Cecilie; Claus, Simon; Ferná ndez de Puelles, Marí a L.; Fonda-Umani, Serena; Hoarau, Galice; Mazzocchi, Maria G.; Mozetič, Patricija; Vandepitte, Leen; Verí ssimo, Helena; Zervoudaki, Soultana; Borja, Angel

    2016-01-01

    Dispersal plays a key role to connect populations and, if limited, is one of the main processes to maintain and generate regional biodiversity. According to neutral theories of molecular evolution and biodiversity, dispersal limitation of propagules and population stochasticity are integral to shaping both genetic and community structure. We conducted a parallel analysis of biological connectivity at genetic and community levels in marine groups with different dispersal traits. We compiled large data sets of population genetic structure (98 benthic macroinvertebrate and 35 planktonic species) and biogeographic data (2193 benthic macroinvertebrate and 734 planktonic species). We estimated dispersal distances from population genetic data (i.e., FST vs. geographic distance) and from β-diversity at the community level. Dispersal distances ranked the biological groups in the same order at both genetic and community levels, as predicted by organism dispersal ability and seascape connectivity: macrozoobenthic species without dispersing larvae, followed by macrozoobenthic species with dispersing larvae and plankton (phyto- and zooplankton). This ranking order is associated with constraints to the movement of macrozoobenthos within the seabed compared with the pelagic habitat. We showed that dispersal limitation similarly determines the connectivity degree of communities and populations, supporting the predictions of neutral theories in marine biodiversity patterns.

  6. Spatial memory and animal movement.

    Science.gov (United States)

    Fagan, William F; Lewis, Mark A; Auger-Méthé, Marie; Avgar, Tal; Benhamou, Simon; Breed, Greg; LaDage, Lara; Schlägel, Ulrike E; Tang, Wen-wu; Papastamatiou, Yannis P; Forester, James; Mueller, Thomas

    2013-10-01

    Memory is critical to understanding animal movement but has proven challenging to study. Advances in animal tracking technology, theoretical movement models and cognitive sciences have facilitated research in each of these fields, but also created a need for synthetic examination of the linkages between memory and animal movement. Here, we draw together research from several disciplines to understand the relationship between animal memory and movement processes. First, we frame the problem in terms of the characteristics, costs and benefits of memory as outlined in psychology and neuroscience. Next, we provide an overview of the theories and conceptual frameworks that have emerged from behavioural ecology and animal cognition. Third, we turn to movement ecology and summarise recent, rapid developments in the types and quantities of available movement data, and in the statistical measures applicable to such data. Fourth, we discuss the advantages and interrelationships of diverse modelling approaches that have been used to explore the memory-movement interface. Finally, we outline key research challenges for the memory and movement communities, focusing on data needs and mathematical and computational challenges. We conclude with a roadmap for future work in this area, outlining axes along which focused research should yield rapid progress. © 2013 John Wiley & Sons Ltd/CNRS.

  7. Eye Movements in Gaze Interaction

    DEFF Research Database (Denmark)

    Møllenbach, Emilie; Hansen, John Paulin; Lillholm, Martin

    2013-01-01

    Gaze as a sole input modality must support complex navigation and selection tasks. Gaze interaction combines specific eye movements and graphic display objects (GDOs). This paper suggests a unifying taxonomy of gaze interaction principles. The taxonomy deals with three types of eye movements...

  8. Compensatory eye movements in mice

    NARCIS (Netherlands)

    A.M. van Alphen (Arjan)

    2002-01-01

    textabstractThis thesis will address the generation of compensatory eye movements in naturally mutated or genetically modified mice. The reason for generating compensatory eye movements is solely related to the requirements for good vision. In a subject moving through its environment the projection

  9. Movement Patterns in Educational Games

    DEFF Research Database (Denmark)

    Rehm, Matthias; Christensen, Bianca Clavio; Nielsen, Thorsten B.

    2018-01-01

    Although movement is essential in location-based games to get from one point of interest to the next, it is seldom taken into account for the game design and the selection of locations. Instead, player movement is usually analyzed after the fact, i.e. when the game is ready to play. In this paper......-based educational games....

  10. Music and Movement. Beginnings Workshop.

    Science.gov (United States)

    Smith, Cindy; Moore, Thomas; Carlton, Elizabeth B.; Kranowitz, Carol Stock

    2000-01-01

    Four articles address music and movement in early childhood education: (1) "For the Love of Music--and Children"(Cindy Smith); (2) "Music: The Great Connector" (Thomas Moore); (3) "Learning through Music: The Support of Brain Research" (Elizabeth B. Carlton); and (4) "Music and Movement Bring Together Children of…

  11. A dynamic approach for the impact of a toxic gas dispersion hazard considering human behaviour and dispersion modelling.

    Science.gov (United States)

    Lovreglio, Ruggiero; Ronchi, Enrico; Maragkos, Georgios; Beji, Tarek; Merci, Bart

    2016-11-15

    The release of toxic gases due to natural/industrial accidents or terrorist attacks in populated areas can have tragic consequences. To prevent and evaluate the effects of these disasters different approaches and modelling tools have been introduced in the literature. These instruments are valuable tools for risk managers doing risk assessment of threatened areas. Despite the significant improvements in hazard assessment in case of toxic gas dispersion, these analyses do not generally include the impact of human behaviour and people movement during emergencies. This work aims at providing an approach which considers both modelling of gas dispersion and evacuation movement in order to improve the accuracy of risk assessment for disasters involving toxic gases. The approach is applied to a hypothetical scenario including a ship releasing Nitrogen dioxide (NO2) on a crowd attending a music festival. The difference between the results obtained with existing static methods (people do not move) and a dynamic approach (people move away from the danger) which considers people movement with different degrees of sophistication (either a simple linear path or more complex behavioural modelling) is discussed. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. The ecological movement in France

    International Nuclear Information System (INIS)

    Taccoen, L.B.C.

    1977-01-01

    The anti-nuclear movements in France are part of a broader movement which, following common usage, the author calls the Ecological Movement. In France, the movement can be divided into a fairly small politically oriented core, numerous and varied associations for the defence of the environment, and a number of consumer associations. The movement cannot be classified politically, which accounts for the attitude of the political parties - distrust of the ''ecologists'', but considerable interest in them as voters. Those with responsibility for power generation must explain to the population at large the energy problem and the importance of economic growth in raising wages and reducing unemployment. They must also explain why nuclear power generation is one of the safest technologies existing at present. (author)

  13. On Biometrics With Eye Movements.

    Science.gov (United States)

    Zhang, Youming; Juhola, Martti

    2017-09-01

    Eye movements are a relatively novel data source for biometric identification. When video cameras applied to eye tracking become smaller and more efficient, this data source could offer interesting opportunities for the development of eye movement biometrics. In this paper, we study primarily biometric identification as seen as a classification task of multiple classes, and secondarily biometric verification considered as binary classification. Our research is based on the saccadic eye movement signal measurements from 109 young subjects. In order to test the data measured, we use a procedure of biometric identification according to the one-versus-one (subject) principle. In a development from our previous research, which also involved biometric verification based on saccadic eye movements, we now apply another eye movement tracker device with a higher sampling frequency of 250 Hz. The results obtained are good, with correct identification rates at 80-90% at their best.

  14. Eye movement perimetry in glaucoma.

    Science.gov (United States)

    Trope, G E; Eizenman, M; Coyle, E

    1989-08-01

    Present-day computerized perimetry is often inaccurate and unreliable owing to the need to maintain central fixation over long periods while repressing the normal response to presentation of peripheral stimuli. We tested a new method of perimetry that does not require prolonged central fixation. During this test eye movements were encouraged on presentation of a peripheral target. Twenty-three eyes were studied with an Octopus perimeter, with a technician monitoring eye movements. The sensitivity was 100% and the specificity 23%. The low specificity was due to the technician's inability to accurately monitor small eye movements in the central 6 degrees field. If small eye movements are monitored accurately with an eye tracker, eye movement perimetry could become an alternative method to standard perimetry.

  15. Measuring dispersal as distance-dependent recruitment rates: testing the performance of DDRR on simulated data.

    NARCIS (Netherlands)

    Van Noordwijk, A.J.

    2011-01-01

    Dispersal is an important process in ecology, but its measurement is difficult. In particular, natal dispersal— the net movement between site of birth and site of first reproduction—is important, since it determines population structure. Using simulated data, I study the claim that measuring

  16. Short-term dispersal response of an endangered Australian lizard varies with time of year.

    Directory of Open Access Journals (Sweden)

    Mehregan Ebrahimi

    Full Text Available Dispersal is an important component in the demography of animal populations. Many animals show seasonal changes in their tendency to disperse, reflecting changes in resource availability, mating opportunities, or in population age structure at the time when new offspring enter the population. Understanding when and why dispersal occurs can be important for the management of endangered species. The pygmy bluetongue lizard is an endangered Australian species that occupies and defends single burrow refuges for extended periods of time, rarely moving far from the burrow entrance. However, previous pitfall trapping data have suggested movement of adult males in spring and of juveniles in autumn of each year. In the current study we compared behaviours of adult lizards each month, over the spring-summer activity period over two consecutive field seasons, to provide deeper understanding of the seasonal dispersal pattern. We released adult pygmy bluetongue lizards into a central area, provided with artificial burrows, within large enclosures, and monitored the behaviour and movements of the released lizards over a four day period. There was a consistent decline in time spent basking, amount of movement around burrow entrances, and rates of dispersal from the central release area from early spring to late summer. Results could be relevant to understanding and managing natural populations and for any translocation attempts of this endangered lizard species.

  17. Granular controls on the dispersion of bed load tracers

    Science.gov (United States)

    Jerolmack, D. J.; Martin, R. L.; Phillips, C. B.

    2014-12-01

    Coarse particles are transported in a river as bed load, i.e., they move in frequent contact with and are supported by the granular bed. This movement is typically intermittent and may be described by a series of steps are rests, the distributions of which determine particle dispersion. Laboratory and field studies of bed load tracer dispersion have reported sub- and super-diffusive behavior, both of which have been successfully reproduced with stochastic transport models. Although researchers have invoked heavy-tailed step lengths as the cause of anomalous dispersion, most observations report thin-tailed distributions. Little attention has been paid to rest periods, and stochastic transport models have not been connected to the underlying mechanics of particle motion. Based on theoretical and experimental evidence, we argue that step lengths are thin-tailed and do not control the longterm dispersion of bed load tracers; they are determined by momentum balance between the fluid and solid. Using laboratory experiments with both marbles and natural sediments, we demonstrate that the rest time distribution is power law, and argue that this distribution controls asymptotic dispersion. Observed rest times far exceed any hydrodynamic timescale. Experiments reveal that rest times of deposited particles are governed by fluctuations in river bed elevation; in particular, the return time for the bed to scour to the base of a deposited particle. Stochastic fluctuations in bed elevation are describable by an Ornstein-Uhlenbeck (mean-reverting random walk) model that contains two parameters, which we show are directly related to the granular shear rate and range of bed elevation fluctuations, respectively. Combining these results with the theory of asymmetric random walks (particles only move downstream), we predict superdiffusive behavior that is in quantitative agreement with our observations of tracer dispersion in a natural river.

  18. Biomimetics on seed dispersal: survey and insights for space exploration

    International Nuclear Information System (INIS)

    Pandolfi, Camilla; Izzo, Dario

    2013-01-01

    Seeds provide the vital genetic link and dispersal agent between successive generations of plants. Without seed dispersal as a means of reproduction, many plants would quickly die out. Because plants lack any sort of mobility and remain in the same spot for their entire lives, they rely on seed dispersal to transport their offspring throughout the environment. This can be accomplished either collectively or individually; in any case as seeds ultimately abdicate their movement, they are at the mercy of environmental factors. Thus, seed dispersal strategies are characterized by robustness, adaptability, intelligence (both behavioral and morphological), and mass and energy efficiency (including the ability to utilize environmental sources of energy available): all qualities that advanced engineering systems aim at in general, and in particular those that need to enable complex endeavors such as space exploration. Plants evolved and adapted their strategy according to their environment, and taken together, they enclose many desirable characteristics that a space mission needs to have. Understanding in detail how plants control the development of seeds, fabricate structural components for their dispersal, build molecular machineries to keep seeds dormant up to the right moment and monitor the environment to release them at the right time could provide several solutions impacting current space mission design practices. It can lead to miniaturization, higher integration and packing efficiency, energy efficiency and higher autonomy and robustness. Consequently, there would appear to be good reasons for considering biomimetic solutions from plant kingdom when designing space missions, especially to other celestial bodies, where solid and liquid surfaces, atmosphere, etc constitute and are obviously parallel with the terrestrial environment where plants evolved. In this paper, we review the current state of biomimetics on seed dispersal to improve space mission design

  19. Numerical methods of estimating the dispersion of radionuclides in atmosphere

    International Nuclear Information System (INIS)

    Vladu, Mihaela; Ghitulescu, Alina; Popescu, Gheorghe; Piciorea, Iuliana

    2007-01-01

    depending on the source configuration and meteorological conditions. In case of accidental situations, it would be necessary to examine the local atmospheric conditions and the range of impact around a nuclear power plant. In case that wind direction, at emission height, is not available by metering, it must be calculated on the basis of wind speed measured at 10 m height from the ground. The spatial and temporal dispersion of radioactive substances released from a nuclear facility is established through three methods of wind speed evaluation (transport) and through atmosphere turbulence movement (diffusion). The transportation process determines the direction followed by radioactive plumage and the time necessary for the transport up to a given location. (authors)

  20. Movement disorders in hereditary ataxias.

    Science.gov (United States)

    Garcia Ruiz, Pedro J; Mayo, David; Hernandez, Jaime; Cantarero, Susana; Ayuso, Carmen

    2002-10-15

    Movement disorders are well known features of some dominant hereditary ataxias (HA), specially SCA3/Machado-Joseph disease and dentatorubropallidolusyan atrophy. However, little is known about the existence and classification of movement disorders in other dominant and recessive ataxias. We prospectively studied the presence of movement disorders in patients referred for HA over the last 3 years. Only those patients with a confirmed family history of ataxia were included. We studied 84 cases of HA, including 46 cases of recessive and 38 cases of dominant HA. Thirty out of 46 cases of recessive HA could be classified as: Friedreich ataxia (FA), 29 cases; vitamin E deficiency, 1 case. Twenty-three out of 38 cases of dominant HA could be classified as: SCA 2, 4 cases; SCA 3, 8 cases; SCA 6, 4 cases; SCA 7, 6 cases and SCA 8, 1 case. We observed movement disorders in 20/38 (52%) patients with dominant HA and 25/46 (54%) cases with recessive HA, including 16 patients (16/29) with FA. In general, postural tremor was the most frequent observed movement disorder (27 cases), followed by dystonia (22 cases). Five patients had akinetic rigid syndrome, and in 13 cases, several movement disorders coexisted. Movement disorders are frequent findings in HA, not only in dominant HA but also in recessive HA. Copyright 2002 Elsevier Science B.V.

  1. Does the cerebellum initiate movement?

    Science.gov (United States)

    Thach, W T

    2014-02-01

    Opinion is divided on what the exact function of the cerebellum is. Experiments are summarized that support the following views: (1) the cerebellum is a combiner of multiple movement factors; (2) it contains anatomically fixed permanent focal representation of individual body parts (muscles and segments) and movement modes (e.g., vestibular driven vs. cognitive driven); (3) it contains flexible changing representations/memory of physical properties of the body parts including muscle strength, segment inertia, joint viscosity, and segmental interaction torques (dynamics); (4) it contains mechanisms for learning and storage of the properties in item no. 3 through trial-and-error practice; (5) it provides for linkage of body parts, motor modes, and motordynamics via the parallel fiber system; (6) it combines and integrates the many factors so as to initiate coordinated movements of the many body parts; (7) it is thus enabled to play the unique role of initiating coordinated movements; and (8) this unique causative role is evidenced by the fact that: (a) electrical stimulation of the cerebellum can initiate compound coordinated movements; (b) in naturally initiated compound movements, cerebellar discharge precedes that in downstream target structures such as motor cerebral cortex; and (c) cerebellar ablation abolishes the natural production of compound movements in the awake alert individuals.

  2. Analysis on the atmospheric dispersion of radioactive materials

    International Nuclear Information System (INIS)

    Nagai, Haruyasu

    2012-01-01

    JAEA has been developing a new prediction system of comprehensive movement, SPEEDI-MP (SPEEDI Multi-model Package), which can treat continuously and strictly with the migration behavior of radioactive materials at atmosphere, sea, and land region. JAEA has been further promoting the detail analysis of atmospheric migration of radioactive materials dispersed by an accident. Then, using a part of this system, the atmospheric-diversion prediction system, WSPEEDI-II, the atmospheric diversion mass and the atmospheric diffusion analysis were carried out. This issue reports the summary. (M.H.)

  3. Jellyfish movement data - Determining Movement Patterns of Jellyfish

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This project is to determine horizontal and vertical movement patterns of two jellyfish species in Hood Canal, in relation to environmental variables. It is being...

  4. Atmospheric dispersion of radioactive materials

    International Nuclear Information System (INIS)

    Chino, Masamichi

    1988-01-01

    The report describes currently available techniques for predicting the dispersion of accidentally released radioactive materials and techniques for visualization using computer graphics. A simulation study is also made on the dispersion of radioactive materials released from the Chernobyl plant. The simplest models include the Gauss plume model and the puff model, which cannot serve to analyze the effects of the topography, vertical wind shear, temperature inversion layer, etc. Numerical analysis methods using advection and dispersion equations are widely adopted for detailed evaluation of dispersion in an emergency. An objective analysis model or a hydrodynamical model is often used to calculate the air currents which are required to determine the advection. A small system based on the puff model is widely adopted in Europe, where the topography is considered to have only simple effects. A more sophisticated large-sized system is required in nuclear facilities located in an area with more complex topographic features. An emergency system for dispersion calculation should be equipped with a graphic display to serve for quick understanding of the radioactivity distribution. (Nogami, K.)

  5. Magnetoencephalographic study on facial movements

    Directory of Open Access Journals (Sweden)

    Kensaku eMiki

    2014-07-01

    Full Text Available In this review, we introduced our three studies that focused on facial movements. In the first study, we examined the temporal characteristics of neural responses elicited by viewing mouth movements, and assessed differences between the responses to mouth opening and closing movements and an averting eyes condition. Our results showed that the occipitotemporal area, the human MT/V5 homologue, was active in the perception of both mouth and eye motions. Viewing mouth and eye movements did not elicit significantly different activity in the occipitotemporal area, which indicated that perception of the movement of facial parts may be processed in the same manner, and this is different from motion in general. In the second study, we investigated whether early activity in the occipitotemporal region evoked by eye movements was influenced by a face contour and/or features such as the mouth. Our results revealed specific information processing for eye movements in the occipitotemporal region, and this activity was significantly influenced by whether movements appeared with the facial contour and/or features, in other words, whether the eyes moved, even if the movement itself was the same. In the third study, we examined the effects of inverting the facial contour (hair and chin and features (eyes, nose, and mouth on processing for static and dynamic face perception. Our results showed the following: (1 In static face perception, activity in the right fusiform area was affected more by the inversion of features while that in the left fusiform area was affected more by a disruption in the spatial relationship between the contour and features, and (2 In dynamic face perception, activity in the right occipitotemporal area was affected by the inversion of the facial contour.

  6. Dance movement therapy for dementia.

    Science.gov (United States)

    Karkou, Vicky; Meekums, Bonnie

    2017-02-03

    Dementia is a collective name for different degenerative brain syndromes which, according to Alzheimer's Disease International, affects approximately 35.6 million people worldwide. The latest NICE guideline for dementia highlights the value of diverse treatment options for the different stages and symptoms of dementia including non-pharmacological treatments. Relevant literature also argues for the value of interventions that acknowledge the complexity of the condition and address the person as a whole, including their physical, emotional, social and cognitive processes. At the same time, there is growing literature that highlights the capacity of the arts and embodied practices to address this complexity. Dance movement therapy is an embodied psychological intervention that can address complexity and thus, may be useful for people with dementia, but its effectiveness remains unclear. To assess the effects of dance movement therapy on behavioural, social, cognitive and emotional symptoms of people with dementia in comparison to no treatment, standard care or any other treatment. Also, to compare different forms of dance movement therapy (e.g. Laban-based dance movement therapy, Chacian dance movement therapy or Authentic Movement). Searches took place up to March 2016 through ALOIS, Cochrane Dementia and Cognitive Improvement's Specialized Register, which covers CENTRAL, a number of major healthcare databases and trial registers, and grey literature sources. We checked bibliographies of relevant studies and reviews, and contacted professional associations, educational programmes and experts from around the world. We considered randomised controlled trials (RCTs) in any language, including cross-over design and cluster-RCTs for inclusion. Studies considered had to include people with dementia, in any age group and in any setting, with interventions delivered by a dance movement therapy practitioner who (i) had received formal training (ii) was a dance movement

  7. Air movement - good or bad?

    DEFF Research Database (Denmark)

    Toftum, Jørn

    2004-01-01

    when air movement is desirable and when it is not. At temperatures up to 22-23oC, at sedentary activity and with occupants feeling neutral or cooler there is a risk of air movement being perceived as unacceptable, even at low velocities. In particular, a cool overall thermal sensation negatively...... influences the subjective perception of air movement. With occupants feeling warmer than neutral, at temperatures above 23oC or at raised activity levels, humans generally do not feel draught at air velocities typical for indoor environments (up to around 0.4 m/s). In the higher temperature range, very high...

  8. Prediction of short-distance aerial movement of Phakopsora pachyrhizi urediniospores using machine learning

    Science.gov (United States)

    Dispersal of urediniospores by wind is the primary means of spread for Phakopsora pachyrhizi, the cause of soybean rust. Our research focused on the short distance movement of urediniospores from within the soybean canopy and up to 61 m from field-grown soybean rust infected plants. Environmental va...

  9. The movement ecology and dynamics of plant communities in fragmented landscapes.

    Science.gov (United States)

    Damschen, Ellen I; Brudvig, Lars A; Haddad, Nick M; Levey, Douglas J; Orrock, John L; Tewksbury, Joshua J

    2008-12-09

    A conceptual model of movement ecology has recently been advanced to explain all movement by considering the interaction of four elements: internal state, motion capacity, navigation capacities, and external factors. We modified this framework to generate predictions for species richness dynamics of fragmented plant communities and tested them in experimental landscapes across a 7-year time series. We found that two external factors, dispersal vectors and habitat features, affected species colonization and recolonization in habitat fragments and their effects varied and depended on motion capacity. Bird-dispersed species richness showed connectivity effects that reached an asymptote over time, but no edge effects, whereas wind-dispersed species richness showed steadily accumulating edge and connectivity effects, with no indication of an asymptote. Unassisted species also showed increasing differences caused by connectivity over time, whereas edges had no effect. Our limited use of proxies for movement ecology (e.g., dispersal mode as a proxy for motion capacity) resulted in moderate predictive power for communities and, in some cases, highlighted the importance of a more complete understanding of movement ecology for predicting how landscape conservation actions affect plant community dynamics.

  10. Long-distance seed dispersal by straw-coloured fruit bats varies by season and landscape

    Directory of Open Access Journals (Sweden)

    Michael Abedi-Lartey

    2016-07-01

    Full Text Available On-going fragmentation of tropical forest ecosystems and associated depletion of seed dispersers threatens the long-term survival of animal-dispersed plants. These threats do not only affect biodiversity and species abundance, but ultimately ecosystem functions and services. Thus, seed dispersers such as the straw-coloured fruit bat, E. helvum, which traverse long distances across fragmented landscapes, are particularly important for maintaining genetic connectivity and colonizing new sites for plant species. Using high-resolution GPS-tracking of movements, field observations and gut retention experiments, we quantify dispersal distances for small- and large-seeded fruits foraged by E. helvum during periods of colony population low (wet season and high (dry season in an urban and a rural landscape in the forest zone of Ghana. Gut passage time averaged 116 min (range 4–1143 min, comparable to other fruit bats. Movements were generally longer in the urban than in the rural landscape and also longer in the dry than in the wet season. As the majority of seeds are dispersed only to feeding roosts, median dispersal distances were similar for both large (42–67 m and small (42–65 m seeds. However, small seeds were potentially dispersed up to 75.4 km, four times further than the previous maximum distance estimated for a similar-sized frugivore. Maximum seed dispersal distances for small seeds were almost twice as long in the rural (49.7 km compare to the urban (31.2 km landscape. Within the urban landscape, estimated maximum dispersal distances for small seeds were three times longer during the dry season (75.4 km compared to the wet season (22.8 km; in contrast, distances in the rural landscape were three times longer in the wet season (67 km compared to the dry season (24.4. Dispersal distances for large seeds during the dry season (551 m in the rural landscape were almost twice that in the wet season (319 m. We found no influence of food

  11. Micromixer based on Taylor dispersion

    International Nuclear Information System (INIS)

    Yang, H; Nguyen, N-T; Huang, X

    2006-01-01

    This paper reports an analytical model, the fabrication and the characterization of a polymeric micromixer based on Taylor dispersion. Due to the distributed velocity field over the channel cross section, the effective dispersion in axial direction in a microchannel is much stronger than the pure molecular diffusion. In our work, squential segmentation was used in the micromixer for improving mixing in a microchannel. The micromixer was designed and fabricated based on lamination of five 100-μm-thick polymer sheets. Rubber valve seats were embedded between the forth and the fifth layers. The polymer layers were machined using a CO 2 laser. The lamination of the five layers was carried out by a commercial hot laminator (Aurora LM-450HC). External solenoid actuators are used for closing the valves at the mixer inlets. The experimental results confirm the effect of Taylor dispersion. Mixing ratio can be adjusted by pulse width modulation of the control signal of the solenoids

  12. Improving IUE High Dispersion Extraction

    Science.gov (United States)

    Lawton, Patricia J.; VanSteenberg, M. E.; Massa, D.

    2007-01-01

    We present a different method to extract high dispersion International Ultraviolet Explorer (IUE) spectra from the New Spectral Image Processing System (NEWSIPS) geometrically and photometrically corrected (SI HI) images of the echellogram. The new algorithm corrects many of the deficiencies that exist in the NEWSIPS high dispersion (SIHI) spectra . Specifically, it does a much better job of accounting for the overlap of the higher echelle orders, it eliminates a significant time dependency in the extracted spectra (which can be traced to the background model used in the NEWSIPS extractions), and it can extract spectra from echellogram images that are more highly distorted than the NEWSIPS extraction routines can handle. Together, these improvements yield a set of IUE high dispersion spectra whose scientific integrity is sign ificantly better than the NEWSIPS products. This work has been supported by NASA ADP grants.

  13. The Effects of Dispersal and Predator Density on Prey Survival in an Insect-Red Clover Metacommunity.

    Science.gov (United States)

    Stasek, David J; Radl, James N; Crist, Thomas O

    2018-01-01

    Trophic interactions are often studied within habitat patches, but among-patch dispersal of individuals may influence local patch dynamics. Metacommunity concepts incorporate the effects of dispersal on local and community dynamics. There are few experimental tests of metacommunity theory using insects compared to those conducted in microbial microcosms. Using connected experimental mesocosms, we varied the density of the leafhopper Agallia constricta Van Duzee (Homoptera: Cicadellidae) and a generalist insect predator, the damsel bug (Nabis spp., Heteroptera: Nabidae), to determine the effects of conspecific and predator density and varying the time available to dispersal among mesocosms on predation rates, dispersal rates, and leafhopper survival. Conspecific and damsel bug density did not affect dispersal rates in leafhoppers, but this may be due to leafhoppers' aversion to leaving the host plants or the connecting tubes between mesocosms hindering leafhopper movement. Leafhopper dispersal was higher in high-dispersal treatments. Survival rates of A. constricta were also lowest in treatments where dispersal was not limited. This is one of the first experimental studies to vary predator density and the time available to dispersal. Our results indicate that dispersal is the key to understanding short-term processes such as prey survival in predator-prey metacommunities. Further work is needed to determine how dispersal rates influence persistence of communities in multigenerational studies. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America.

  14. STELLAR MASS DEPENDENT DISK DISPERSAL

    International Nuclear Information System (INIS)

    Kennedy, Grant M.; Kenyon, Scott J.

    2009-01-01

    We use published optical spectral and infrared (IR) excess data from nine young clusters and associations to study the stellar mass dependent dispersal of circumstellar disks. All clusters older than ∼3 Myr show a decrease in disk fraction with increasing stellar mass for solar to higher mass stars. This result is significant at about the 1σ level in each cluster. For the complete set of clusters we reject the null hypothesis-that solar and intermediate-mass stars lose their disks at the same rate-with 95%-99.9% confidence. To interpret this behavior, we investigate the impact of grain growth, binary companions, and photoevaporation on the evolution of disk signatures. Changes in grain growth timescales at fixed disk temperature may explain why early-type stars with IR excesses appear to evolve faster than their later-type counterparts. Little evidence that binary companions affect disk evolution suggests that photoevaporation is the more likely mechanism for disk dispersal. A simple photoevaporation model provides a good fit to the observed disk fractions for solar and intermediate-mass stars. Although the current mass-dependent disk dispersal signal is not strong, larger and more complete samples of clusters with ages of 3-5 Myr can improve the significance and provide better tests of theoretical models. In addition, the orbits of extra-solar planets can constrain models of disk dispersal and migration. We suggest that the signature of stellar mass dependent disk dispersal due to photoevaporation may be present in the orbits of observed extra-solar planets. Planets orbiting hosts more massive than ∼1.6 M sun may have larger orbits because the disks in which they formed were dispersed before they could migrate.

  15. Dispersion of multi-walled carbon nanotubes in biocompatible dispersants

    International Nuclear Information System (INIS)

    Piret, J.-P.; Detriche, S.; Vigneron, R.; Vankoningsloo, S.; Rolin, S.; Mejia Mendoza, J. H.; Masereel, B.; Lucas, S.; Delhalle, J.; Luizi, F.; Saout, C.; Toussaint, O.

    2010-01-01

    Owing to their phenomenal electrical and mechanical properties, carbon nanotubes (CNT) have been an area of intense research since their discovery in 1991. Different applications for these nanoparticles have been proposed, among others, in electronics and optics but also in the medical field. In parallel, emerging studies have suggested potential toxic effects of CNT while others did not, generating some conflicting outcomes. These discrepancies could be, in part, due to different suspension approaches used and to the agglomeration state of CNT in solution. In this study, we described a standardized protocol to obtain stable CNT suspensions, using two biocompatible dispersants (Pluronic F108 and hydroxypropylcellulose) and to estimate the concentration of CNT in solution. CNT appear to be greatly individualized in these two dispersants with no detection of remaining bundles or agglomerates after sonication and centrifugation. Moreover, CNT remained perfectly dispersed when added to culture medium used for in vitro cell experiments. We also showed that Pluronic F108 is a better dispersant than hydroxypropylcellulose. In conclusion, we have developed a standardized protocol using biocompatible surfactants to obtain reproducible and stable multi-walled carbon nanotubes suspensions which can be used for in vitro or in vivo toxicological studies.

  16. Surgical management of movement disorders

    African Journals Online (AJOL)

    together as movement disorders (e.g. Parkinson's disease, dystonia, essential tremor) is with medication and, in some, with ... Stereotactic lesioning of basal ganglia and/or thalamic targets ... and there is some concern related to suicide.

  17. Neuroimaging findings in movement disorders

    International Nuclear Information System (INIS)

    Topalov, N.

    2015-01-01

    Full text: Neuroimaging methods are of great importance for the differential diagnostic delimitation of movement disorders associated with structural damage (neoplasms, ischemic lesions, neuroinfections) from those associated with specific pathophysiological mechanisms (dysmetabolic disorders, neurotransmitter disorders). Learning objective: Presentation of typical imaging findings contributing to nosological differentiation in groups of movement disorders with similar clinical signs. In this presentation are discussed neuroimaging findings in Parkinson‘s disease, atypical parkinsonian syndromes (multiple system atrophy, progressive supranuclear palsy, corticobasal degeneration), parkinsonism in genetically mediated diseases (Wilson’s disease, pantothenate kinase-associated neurodegeneration – PKAN), vascular parkinsonism, hyperkinetic movement disorders (palatal tremor, Huntington‘s chorea, symptomatic chorea in ischemic stroke and diabetes, rubral tremor, ballismus, hemifacial spasm). Contemporary neuroimaging methods enable support for diagnostic and differential diagnostic precision of a number of hypo- and hyperkinetic movement disorders, which is essential for neurological clinical practice

  18. Eye Movements When Viewing Advertisements

    Directory of Open Access Journals (Sweden)

    Emily eHiggins

    2014-03-01

    Full Text Available In this selective review, we examine key findings on eye movements when viewing advertisements. We begin with a brief, general introduction to the properties and neural underpinnings of saccadic eye movements. Next, we provide an overview of eye movement behavior during reading, scene perception, and visual search, since each of these activities is, at various times, involved in viewing ads. We then review the literature on eye movements when viewing print ads and warning labels (of the kind that appear on alcohol and tobacco ads, before turning to a consideration of advertisements in dynamic media (television and the Internet. Finally, we propose topics and methodological approaches that may prove to be useful in future research.

  19. Healthy Movements: Your Body's Mechanics

    Science.gov (United States)

    ... body, are governed by the same basic physical laws,” says Dr. Jeffrey Weiss, a biomechanics expert at ... for movement disorders such as cerebral palsy and Parkinson’s disease. Joints are a common source of problems ...

  20. Extremely long-distance seed dispersal by an overfished Amazonian frugivore.

    Science.gov (United States)

    Anderson, Jill T; Nuttle, Tim; Saldaña Rojas, Joe S; Pendergast, Thomas H; Flecker, Alexander S

    2011-11-22

    Throughout Amazonia, overfishing has decimated populations of fruit-eating fishes, especially the large-bodied characid, Colossoma macropomum. During lengthy annual floods, frugivorous fishes enter vast Amazonian floodplains, consume massive quantities of fallen fruits and egest viable seeds. Many tree and liana species are clearly specialized for icthyochory, and seed dispersal by fish may be crucial for the maintenance of Amazonian wetland forests. Unlike frugivorous mammals and birds, little is known about seed dispersal effectiveness of fishes. Extensive mobility of frugivorous fish could result in extremely effective, multi-directional, long-distance seed dispersal. Over three annual flood seasons, we tracked fine-scale movement patterns and habitat use of wild Colossoma, and seed retention in the digestive tracts of captive individuals. Our mechanistic model predicts that Colossoma disperses seeds extremely long distances to favourable habitats. Modelled mean dispersal distances of 337-552 m and maximum of 5495 m are among the longest ever reported. At least 5 per cent of seeds are predicted to disperse 1700-2110 m, farther than dispersal by almost all other frugivores reported in the literature. Additionally, seed dispersal distances increased with fish size, but overfishing has biased Colossoma populations to smaller individuals. Thus, overexploitation probably disrupts an ancient coevolutionary relationship between Colossoma and Amazonian plants.

  1. Game Movement as Enactive Focalization

    Directory of Open Access Journals (Sweden)

    Yotam Shibolet

    2018-01-01

    Full Text Available This paper integrates thought on game narrative and embodied cognition, in order to consider the significance of movement to the embodied narrative experience of games. If games are a mode of ‘environmental storytelling’, determining the player’s mobile situatedness within the gamespace is of crucial importance. The metaphor of game design as narrative architecture should be expanded to include te the design of movement dynamics, alongside geographical gamespace. I suggest a theoretical infrastructure that aims to enable further analysis of movement design’s role in this scope. The theory of enactive perception asserts that all perception is inherently negotiated through embodied understanding of moving within environment. According to this model, by giving meaning to perception, movement is also directly related to the structure of consciousness and thought. Cognitive definitions of ‘narrative’ that integrate embodiment are applied to argue it can relevantly account for part of thought’s role in enactive perception. Mieke Bal’s concept of focalization (1997 broaches narrative perspective by underscoring the constant “movement of the look”. For enactive perception, such mobility should be understood as inseparable from the movement of the body even when perspective could appear detached from embodiment. Therefore, I offer the supplementary concept of “enactive focalization” – narrative perception as interpreted through the interconnected dynamics or perspectival and physical movement. To exemplify my ideas and the potential of future research in this scope, I discuss the uniquely effective and affective movement dynamic design of Journey. This paper concludes by reflecting on enactive focalization in light of the increased utilization of embodiment in the contemporary digital media landscape.

  2. THE MOVEMENT SYSTEM IN EDUCATION.

    Science.gov (United States)

    Hoogenboom, Barbara J; Sulavik, Mark

    2017-11-01

    Although many physical therapists have begun to focus on movement and function in clinical practice, a significant number continue to focus on impairments or pathoanatomic models to direct interventions. This paradigm may be driven by the current models used to direct and guide curricula used for physical therapist education. The methods by which students are educated may contribute to a focus on independent systems, rather than viewing the body as a functional whole. Students who enter practice must be able to integrate information across multiple systems that affect a patient or client's movement and function. Such integration must be taught to students and it is the responsibility of those in physical therapist education to embrace and teach the next generation of students this identifying professional paradigm of the movement system. The purpose of this clinical commentary is to describe the current state of the movement system in physical therapy education, suggest strategies for enhancing movement system focus in entry level education, and envision the future of physical therapy education related to the movement system. Contributions by a student author offer depth and perspective to the ideas and suggestions presented. 5.

  3. Movement games in sports training of children

    OpenAIRE

    Komoň, Tomáš

    2015-01-01

    Title: Movement Games in Sports Training of Children Objectives: Create a systemized inventory of movement games. Movement games categorized according to which football skills can developed. Verify popularity of the each movement game in simple questionnaire. Methods: The literature search and data analysis. Also, quantitative research in the form of a simple questionnaire. Results: Systematized inventory of 39 movement games with methodological descriptions. Each movement game has feedback i...

  4. DIMO, a plant dispersal model

    NARCIS (Netherlands)

    Wamelink, G.W.W.; Jochem, R.; Greft, van der J.G.M.; Franke, J.; Malinowska, A.H.; Geertsema, W.; Prins, A.H.; Ozinga, W.A.; Hoek, van der D.C.J.; Grashof-Bokdam, C.J.

    2014-01-01

    Due to human activities many natural habitats have become isolated. As a result the dispersal of many plant species is hampered. Isolated populations may become extinct and have a lower probability to become reestablished in a natural way. Moreover, plant species may be forced to migrate to new

  5. A generalized advection dispersion equation

    Indian Academy of Sciences (India)

    This paper examines a possible effect of uncertainties, variability or heterogeneity of any dynamic system when being included in its evolution rule; the notion is illustrated with the advection dispersion equation, which describes the groundwater pollution model. An uncertain derivative is defined; some properties of.

  6. Ability Dispersion and Team Performance

    DEFF Research Database (Denmark)

    Hoogendoorn, Sander; Parker, Simon C.; Van Praag, Mirjam

    What is the effect of dispersed levels of cognitive ability of members of a (business) team on their team's performance? This paper reports the results of a field experiment in which 573 students in 49 teams start up and manage real companies under identical circumstances. We ensured exogenous va...

  7. Statistical description of turbulent dispersion

    NARCIS (Netherlands)

    Brouwers, J.J.H.

    2012-01-01

    We derive a comprehensive statistical model for dispersion of passive or almost passive admixture particles such as fine particulate matter, aerosols, smoke and fumes, in turbulent flow. The model rests on the Markov limit for particle velocity. It is in accordance with the asymptotic structure of

  8. Magnetic exciton dispersion in praseodymium

    DEFF Research Database (Denmark)

    Rainford, B. D.; Houmann, Jens Christian Gylden

    1971-01-01

    Measurements of the dispersion of magnetic excitons have been made in a single crystal of praseodymium metal using inelastic neutron scattering. A preliminary analysis of the data yields the first detailed information about the exchange interactions and the crystal field splittings in the light...... rare-earth metals....

  9. On Dispersion in Visual Photoreceptors

    NARCIS (Netherlands)

    Stavenga, D.G.; Barneveld, H.H. van

    1975-01-01

    An idealized visual pigment absorbance spectrum is used together with a Kramers-Kronig dispersion relation to calculate the contribution of the visual pigment to the refractive index of the fly photoreceptor. It appears that an absorption coefficient of 0.010 µm-1 results in a refractive index

  10. Dispersal in Mastomys natalensis mice

    DEFF Research Database (Denmark)

    Van Hooft, Pim; Cosson, J F; Vibe-Petersen, Solveig

    2008-01-01

    Mastomys natalensis is the major pest rodent in sub-Saharan Africa. In this study, population genetic techniques were used to gain new insights into its dispersal behaviour, a critical parameter in pest management. Using 11 microsatellites, 272 individuals from a 300 ha area in Tanzania were geno...

  11. Urban movements and disempowerment in Perú and Venezuela

    Directory of Open Access Journals (Sweden)

    Daniel H. LEVINE

    2010-10-01

    Full Text Available This paper addresses a core puzzle: why is continued citizen mobilization accompanied by growing disempowerment of those same citizens? Why do movements fail, leaders burn out and members disperse, and what are the implications of this organizational failure for demo¬cratic representation? Our consideration of the issues is rooted in a close examination of urban movements, mobilization, empowerment and disempowerment in the recent experience of Venezuela and Perú. The puzzle that concerns us is of course not limited to these two countries: it is common to all the Andean republics, and in different ways, to much recent experience of urban mobilization in Latin America and beyond. After a brief account of urban citizen move¬ments and politics in our two cases, we outline general reflections on the nature of empowerment and disempowerment, on the peculiar combination of strengths and weaknesses that mark many contemporary movements. A close examination of types of movements and their links with poli¬tical parties and protest follows. The character of city life is important here. We close with analysis of recent waves of urban mobilization in Perú (that sparked the ouster of president Alberto Fujimori and in Venezuela (both for and against president Hugo Chávez Frías, and with reflections on the likely future of empowerment and disempowerment for urban citizens and the implications of this perspective for democratic representation

  12. Understanding movement data and movement processes: current and emerging directions.

    Science.gov (United States)

    Schick, Robert S; Loarie, Scott R; Colchero, Fernando; Best, Benjamin D; Boustany, Andre; Conde, Dalia A; Halpin, Patrick N; Joppa, Lucas N; McClellan, Catherine M; Clark, James S

    2008-12-01

    Animal movement has been the focus on much theoretical and empirical work in ecology over the last 25 years. By studying the causes and consequences of individual movement, ecologists have gained greater insight into the behavior of individuals and the spatial dynamics of populations at increasingly higher levels of organization. In particular, ecologists have focused on the interaction between individuals and their environment in an effort to understand future impacts from habitat loss and climate change. Tools to examine this interaction have included: fractal analysis, first passage time, Lévy flights, multi-behavioral analysis, hidden markov models, and state-space models. Concurrent with the development of movement models has been an increase in the sophistication and availability of hierarchical bayesian models. In this review we bring these two threads together by using hierarchical structures as a framework for reviewing individual models. We synthesize emerging themes in movement ecology, and propose a new hierarchical model for animal movement that builds on these emerging themes. This model moves away from traditional random walks, and instead focuses inference on how moving animals with complex behavior interact with their landscape and make choices about its suitability.

  13. Integrating movement ecology with biodiversity research - exploring new avenues to address spatiotemporal biodiversity dynamics.

    Science.gov (United States)

    Jeltsch, Florian; Bonte, Dries; Pe'er, Guy; Reineking, Björn; Leimgruber, Peter; Balkenhol, Niko; Schröder, Boris; Buchmann, Carsten M; Mueller, Thomas; Blaum, Niels; Zurell, Damaris; Böhning-Gaese, Katrin; Wiegand, Thorsten; Eccard, Jana A; Hofer, Heribert; Reeg, Jette; Eggers, Ute; Bauer, Silke

    2013-01-01

    Movement of organisms is one of the key mechanisms shaping biodiversity, e.g. the distribution of genes, individuals and species in space and time. Recent technological and conceptual advances have improved our ability to assess the causes and consequences of individual movement, and led to the emergence of the new field of 'movement ecology'. Here, we outline how movement ecology can contribute to the broad field of biodiversity research, i.e. the study of processes and patterns of life among and across different scales, from genes to ecosystems, and we propose a conceptual framework linking these hitherto largely separated fields of research. Our framework builds on the concept of movement ecology for individuals, and demonstrates its importance for linking individual organismal movement with biodiversity. First, organismal movements can provide 'mobile links' between habitats or ecosystems, thereby connecting resources, genes, and processes among otherwise separate locations. Understanding these mobile links and their impact on biodiversity will be facilitated by movement ecology, because mobile links can be created by different modes of movement (i.e., foraging, dispersal, migration) that relate to different spatiotemporal scales and have differential effects on biodiversity. Second, organismal movements can also mediate coexistence in communities, through 'equalizing' and 'stabilizing' mechanisms. This novel integrated framework provides a conceptual starting point for a better understanding of biodiversity dynamics in light of individual movement and space-use behavior across spatiotemporal scales. By illustrating this framework with examples, we argue that the integration of movement ecology and biodiversity research will also enhance our ability to conserve diversity at the genetic, species, and ecosystem levels.

  14. Mindful movement and skilled attention

    Science.gov (United States)

    Clark, Dav; Schumann, Frank; Mostofsky, Stewart H.

    2015-01-01

    Bodily movement has long been employed as a foundation for cultivating mental skills such as attention, self-control or mindfulness, with recent studies documenting the positive impacts of mindful movement training, such as yoga and tai chi. A parallel “mind-body connection” has also been observed in many developmental disorders. We elaborate a spectrum of mindfulness by considering ADHD, in which deficient motor control correlates with impaired (disinhibited) behavioral control contributing to defining features of excessive distractibility and impulsivity. These data provide evidence for an important axis of variation for wellbeing, in which skillful cognitive control covaries with a capacity for skillful movement. We review empirical and theoretical literature on attention, cognitive control, mind wandering, mindfulness and skill learning, endorsing a model of skilled attention in which motor plans, attention, and executive goals are seen as mutually co-defining aspects of skilled behavior that are linked by reciprocal inhibitory and excitatory connections. Thus, any movement training should engage “higher-order” inhibition and selection and develop a repertoire of rehearsed procedures that coordinate goals, attention and motor plans. However, we propose that mindful movement practice may improve the functional quality of rehearsed procedures, cultivating a transferrable skill of attention. We adopt Langer’s spectrum of mindful learning that spans from “mindlessness” to engagement with the details of the present task and contrast this with the mental attitudes cultivated in standard mindfulness meditation. We particularly follow Feldenkrais’ suggestion that mindful learning of skills for organizing the body in movement might transfer to other forms of mental activity. The results of mindful movement training should be observed in multiple complementary measures, and may have tremendous potential benefit for individuals with ADHD and other

  15. Mindful Movement and Skilled Attention

    Directory of Open Access Journals (Sweden)

    Dav eClark

    2015-06-01

    Full Text Available Bodily movement has long been employed as a foundation for cultivating mental skills such as attention, self-control or mindfulness, with recent studies documenting the positive impacts of mindful movement training, such as yoga and tai chi. A parallel mind-body connection has also been observed in many developmental disorders. We elaborate a spectrum of mindfulness by considering ADHD, in which deficient motor control correlates with impaired (disinhibited behavioral control contributing to defining features of excessive distractibility and impulsivity. These data provide evidence for an important axis of variation for wellbeing, in which skillful cognitive control covaries with a capacity for skillful movement. We review empirical and theoretical literature on attention, cognitive control, mind wandering, mindfulness and skill learning, endorsing a model of skilled attention in which motor plans, attention, and executive goals are seen as mutually co-defining aspects of skilled behavior that are linked by reciprocal inhibitory and excitatory connections. Thus, any movement training should engage higher-order inhibition and selection and develop a repertoire of rehearsed procedures that coordinate goals, attention and motor plans. However, we propose that mindful movement practice may improve the functional quality of rehearsed procedures, cultivating a transferrable skill of attention. We adopt Langer’s spectrum of mindful learning that spans from mindlessness to engagement with the details of the present task and contrast this with the mental attitudes cultivated in standard mindfulness meditation. We particularly follow Feldenkrais’ suggestion that mindful learning of skills for organizing the body in movement might transfer to other forms of mental activity. The results of mindful movement training should be observed in multiple complementary measures, and may have tremendous potential benefit for individuals with ADHD and other

  16. Hedgerows Have a Barrier Effect and Channel Pollinator Movement in the Agricultural Landscape

    Directory of Open Access Journals (Sweden)

    Klaus Felix

    2015-01-01

    Full Text Available Agricultural intensification and the subsequent fragmentation of semi-natural habitats severely restrict pollinator and pollen movement threatening both pollinator and plant species. Linear landscape elements such as hedgerows are planted for agricultural and conservation purposes to increase the resource availability and habitat connectivity supporting populations of beneficial organisms such as pollinators. However, hedgerows may have unexpected effects on plant and pollinator persistence by not just channeling pollinators and pollen along, but also restricting movement across the strip of habitat. Here, we tested how hedgerows influence pollinator movement and pollen flow. We used fluorescent dye particles as pollen analogues to track pollinator movement between potted cornflowers Centaurea cyanus along and across a hedgerow separating two meadows. The deposition of fluorescent dye was significantly higher along the hedgerow than across the hedgerow and into the meadow, despite comparable pollinator abundances. The differences in pollen transfer suggest that hedgerows can affect pollinator and pollen dispersal by channeling their movement and acting as a permeable barrier. We conclude that hedgerows in agricultural landscapes can increase the connectivity between otherwise isolated plant and pollinator populations (corridor function, but can have additional, and so far unknown barrier effects on pollination services. Functioning as a barrier, linear landscape elements can impede pollinator movement and dispersal, even for highly mobile species such as bees. These results should be considered in future management plans aiming to enhance the persistence of threatened pollinator and plant populations by restoring functional connectivity and to ensure sufficient crop pollination in the agricultural landscape.

  17. Dispersion modeling by kinematic simulation: Cloud dispersion model

    International Nuclear Information System (INIS)

    Fung, J C H; Perkins, R J

    2008-01-01

    A new technique has been developed to compute mean and fluctuating concentrations in complex turbulent flows (tidal current near a coast and deep ocean). An initial distribution of material is discretized into any small clouds which are advected by a combination of the mean flow and large scale turbulence. The turbulence can be simulated either by kinematic simulation (KS) or direct numerical simulation. The clouds also diffuse relative to their centroids; the statistics for this are obtained from a separate calculation of the growth of individual clouds in small scale turbulence, generated by KS. The ensemble of discrete clouds is periodically re-discretized, to limit the size of the small clouds and prevent overlapping. The model is illustrated with simulations of dispersion in uniform flow, and the results are compared with analytic, steady state solutions. The aim of this study is to understand how pollutants disperses in a turbulent flow through a numerical simulation of fluid particle motion in a random flow field generated by Fourier modes. Although this homogeneous turbulent is rather a 'simple' flow, it represents a building block toward understanding pollutant dispersion in more complex flow. The results presented here are preliminary in nature, but we expect that similar qualitative results should be observed in a genuine turbulent flow.

  18. Antinuclear movement in Middle Tennessee

    International Nuclear Information System (INIS)

    Dwyer, L.E.

    1977-01-01

    This is a social anthropological analysis of the antinuclear movement in Middle Tennessee. This social movement was determined to halt the construction of proposed nuclear power plants in Tennessee, especially one the Tennessee Valley Authority (TVA) intended to build in Middle Tennessee. The data for the study were gathered by participant-observation interviewing, and the examination of documents from February 1973 through March 1975. The treatment of the data is based on transactional analysis and portions of the network model. This social movement was composed of a series of informally organized cells connected by a loose network of people who visited and talked with one another. Individual cells tended to be organized on a geographical basis, as was communication. Activity-initiators, however, often contacted antinuclear personnel in other Middle Tennessee cells. Movement activity for many of the antinuclear activists was short-lived. The strategic maneuvers of the movement utilized all the structurally and legally possible alternatives and the nuclear opponents hoped that the public would pressure public officials to oppose nuclear plants. Although the antinuclear activists worked very hard, they did not succeed in halting the planned construction of the Middle Tennessee nuclear plant. Indeed, they had not succeeded in the summer of 1977

  19. The effect of a tall tower on flow and dispersion through a model urban neighborhood: part 2. Pollutant dispersion.

    Science.gov (United States)

    Brixey, Laurie A; Heist, David K; Richmond-Bryant, Jennifer; Bowker, George E; Perry, Steven G; Wiener, Russell W

    2009-12-01

    This article is the second in a two-paper series presenting results from wind tunnel and computational fluid dynamics (CFD) simulations of flow and dispersion in an idealized model urban neighborhood. Pollutant dispersion results are presented and discussed for a model neighborhood that was characterized by regular city blocks of three-story row houses with a single 12-story tower located at the downwind edge of one of these blocks. The tower had three significant effects on pollutant dispersion in the surrounding street canyons: drawing the plume laterally towards the tower, greatly enhancing the vertical dispersion of the plume in the wake of the tower, and significantly decreasing the residence time of pollutants in the wake of the tower. In the wind tunnel, tracer gas released in the avenue lee of the tower, but several blocks away laterally, was pulled towards the tower and lifted in the wake of the tower. The same lateral movement of the pollutant was seen in the next avenue, which was approximately 2.5 tower heights downwind of the tower. The tower also served to ventilate the street canyon directly in its wake more rapidly than the surrounding areas. This was evidenced by CFD simulations of concentration decay where the residence time of pollutants lee of the 12-story tower was found to be less than half the residence time behind a neighboring three-story building. This same phenomenon of rapid vertical dispersion lee of a tower among an array of smaller buildings was also demonstrated in a separate set of wind tunnel experiments using an array of cubical blocks. A similar decrease in the residence time was observed when the height of one block was increased.

  20. UV curable aqueous dispersions for wood coatings

    International Nuclear Information System (INIS)

    Peeters, S.; Bleus, J.P.; Wang, Z.J.; Arceneaux, J. A.; Hall, J.

    1999-01-01

    In this paper the characterisation of aqueous dispersions of UV curable resins is described. Two types of dispersions were used: dispersions that are tacky after water evaporation and tack - free before cure dispersions. The physical and rheological properties of these products have been determined and the performance of these dispersions in various formulations, especially for wood applications has been studied. With these dispersions, it is possible to produce coatings having a good cure speed, good surface hardness and good solvent -, chemical - and water resistance

  1. Laser control of natural disperse systems

    Science.gov (United States)

    Vlasova, Olga L.; Bezrukova, Alexandra G.

    2003-10-01

    Different water disperse systems were studied by integral (spectroturbidemetry) and differential light scattering method with a laser as a source of light. The investigation done concerns the state of kaolin dispersions at storage and under dilution as an example of mineral dispersion systems such as natural water. The role of some light scattering parameters for an optical analysis of water dispersions, like the dispersion of erythrocytes and bacterial cells -Escherichia coli is discussed. The results obtained can help to elaborate the methods for on-line optical control fo natural disperse systems (water, air) with mineral and biological particles.

  2. Nanocomposites from Stable Dispersions of Carbon Nanotubes in Polymeric Matrices Using Dispersion Interaction

    Science.gov (United States)

    Wise, Kristopher Eric (Inventor); Park, Cheol (Inventor); Kang, Jin Ho (Inventor); Siochi, Emilie J. (Inventor); Harrison, Joycelyn S. (Inventor)

    2016-01-01

    Stable dispersions of carbon nanotubes (CNTs) in polymeric matrices include CNTs dispersed in a host polymer or copolymer whose monomers have delocalized electron orbitals, so that a dispersion interaction results between the host polymer or copolymer and the CNTs dispersed therein. Nanocomposite products, which are presented in bulk, or when fabricated as a film, fiber, foam, coating, adhesive, paste, or molding, are prepared by standard means from the present stable dispersions of CNTs in polymeric matrices, employing dispersion interactions, as presented hereinabove.

  3. Transverse dispersion in heterogeneous fractures

    International Nuclear Information System (INIS)

    Dershowitz, Bill; Shuttle, Dawn; Klise, Kate; Outters, Nils; Hermanson, Jan

    2004-12-01

    This report evaluates the significance of transverse dispersion processes for solute transport in a single fracture. Transverse dispersion is a potentially significant process because it increases the fracture surface area available for sorptive and diffusive properties, and has the potential to transport solute between what would otherwise be distinctive, streamline pathways. Transverse dispersion processes are generally ignored in one-dimensional repository performance assessment approaches. This report provides an initial assessment of the magnitude of transverse dispersion effect in a single heterogeneous fracture on repository safety assessment. This study builds on a previous report which considered the network effects on transport dispersion including streamline routing and mixing at fracture intersections. The project uses FracMan software. This platform has been extensively used by SKB in other projects. FracMan software is designed to generate and analyze DFN's as well as to compute fluid flow in DFN's with the MAFIC Finite element method (FEM) code. Solute transport was modeled using the particle tracking inside MAFIC, the 2-D Laplace Transform Galerkin inside PAWorks/LTG, and the 1-D Laplace Transform approach designed to replicate FARF31 inside GoldSim.The study reported here focuses on a single, 20-meter scale discrete fracture, with simplified boundary conditions intended to represent the position of this fracture within a fracture network. The range of assumptions made regarding fracture heterogeneity were as follows: Base case, Heterogeneous fracture, geostatistical field, correlation length 0.01 m. Case 1a, Homogeneous fracture, transmissivity = 10 -7 m 2 /s. Case 1b, Heterogeneous fracture, non-channeled geostatistical field correlation length 5 m. Case 1c, Heterogeneous fracture, channeled, anisotropic geostatistical field. Case 1d, Heterogeneous fracture, fracture intersection zone (FIZ) permeability enhanced. Case 5, Simple channelized

  4. Yarbus, Eye Movements, and Vision

    Directory of Open Access Journals (Sweden)

    Benjamin W Tatler

    2010-04-01

    Full Text Available The impact of Yarbus's research on eye movements was enormous following the translation of his book Eye Movements and Vision into English in 1967. In stark contrast, the published material in English concerning his life is scant. We provide a brief biography of Yarbus and assess his impact on contemporary approaches to research on eye movements. While early interest in his work focused on his study of stabilised retinal images, more recently this has been replaced with interest in his work on the cognitive influences on scanning patterns. We extended his experiment on the effect of instructions on viewing a picture using a portrait of Yarbus rather than a painting. The results obtained broadly supported those found by Yarbus.

  5. 45 CFR 400.119 - Interstate movement.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 2 2010-10-01 2010-10-01 false Interstate movement. 400.119 Section 400.119... Services § 400.119 Interstate movement. After the initial placement of an unaccompanied minor, the same procedures that govern the movement of nonrefugee foster cases to other States apply to the movement of...

  6. Conceptualizing Learning in the Climate Justice Movement

    Science.gov (United States)

    Kluttz, Jenalee; Walter, Pierre

    2018-01-01

    This article extends Scandrett et al.'s conceptual framework for social movement learning to understand learning and knowledge creation in the climate justice movement. Drawing on radical pluralist theoretical approaches to social movement learning, learning in the climate justice movement is conceptualized at the micro, meso, and macro levels,…

  7. Followership in Ecology/Environment Social Movements.

    Science.gov (United States)

    Clavner, Jerry B.; Sumodi, Veronica R.

    The paper analyzes the failure of the ecology/environmental movement to develop into a social movement and to generate a mass following. The movement has had difficulty not only in organizing collective behavior but also in maintaining the necessary momentum to change into a full-fledged social movement. Obvious reasons are that ecologists…

  8. Procedure for preparation of dispersions

    International Nuclear Information System (INIS)

    1978-01-01

    Procedure for the preparation of a water based dispersion of cerium oxide, characterised in that a suspension of cerium (IV) hydroxide is formed with an acid, where the acid is in the state of a disaggregation of aggregated crystalline cerium hydroxide, the suspension being preheated for a specified time and to a specified temperature, so that the pH value becomes constant, and whereby the quantity of acid in the suspension is such that the constant pH value is lower than 5.4, so that a conditioned suspension may be obtained, and water may be mixed with the conditioned suspension for making a water based dispersion of cerium oxide. (G.C.)

  9. Stochastic models for atmospheric dispersion

    DEFF Research Database (Denmark)

    Ditlevsen, Ove Dalager

    2003-01-01

    Simple stochastic differential equation models have been applied by several researchers to describe the dispersion of tracer particles in the planetary atmospheric boundary layer and to form the basis for computer simulations of particle paths. To obtain the drift coefficient, empirical vertical...... positions close to the boundaries. Different rules have been suggested in the literature with justifications based on simulation studies. Herein the relevant stochastic differential equation model is formulated in a particular way. The formulation is based on the marginal transformation of the position...... velocity distributions that depend on height above the ground both with respect to standard deviation and skewness are substituted into the stationary Fokker/Planck equation. The particle position distribution is taken to be uniform *the well/mixed condition( and also a given dispersion coefficient...

  10. Ability Dispersion and Team Performance

    DEFF Research Database (Denmark)

    Hoogendoorn, Sander; Parker, Simon C.; Van Praag, Mirjam

    What is the effect of dispersed levels of cognitive ability of members of a (business) team on their team's performance? This paper reports the results of a field experiment in which 573 students in 49 (student) teams start up and manage real companies under identical circumstances for one year. We...... ensured exogenous variation in otherwise random team composition by assigning students to teams based on their measured cognitive abilities. Each team performs a variety of tasks, often involving complex decision making. The key result of the experiment is that the performance of business teams first...... increases and then decreases with ability dispersion. We seek to understand this finding by developing a model in which team members of different ability levels form sub- teams with other team members with similar ability levels to specialize in different productive tasks. Diversity spreads production over...

  11. Magnetic effects in anomalous dispersion

    International Nuclear Information System (INIS)

    Blume, M.

    1992-01-01

    Spectacular enhancements of magnetic x-ray scattering have been predicted and observed experimentally. These effects are the result of resonant phenomena closely related to anomalous dispersion, and they are strongest at near-edge resonances. The theory of these resonances will be developed with particular attention to the symmetry properties of the scatterer. While the phenomena to be discussed concern magnetic properties the transitions are electric dipole or electric quadrupole in character and represent a subset of the usual anomalous dispersion phenomena. The polarization dependence of the scattering is also considered, and the polarization dependence for magnetic effects is related to that for charge scattering and to Templeton type anisotropic polarization phenomena. It has been found that the strongest effects occur in rare-earths and in actinides for M shell edges. In addition to the scattering properties the theory is applicable to ''forward scattering'' properties such as the Faraday effect and circular dichroism

  12. Faraday anomalous dispersion optical tuners

    Science.gov (United States)

    Wanninger, P.; Valdez, E. C.; Shay, T. M.

    1992-01-01

    Common methods for frequency stabilizing diode lasers systems employ gratings, etalons, optical electric double feedback, atomic resonance, and a Faraday cell with low magnetic field. Our method, the Faraday Anomalous Dispersion Optical Transmitter (FADOT) laser locking, is much simpler than other schemes. The FADOT uses commercial laser diodes with no antireflection coatings, an atomic Faraday cell with a single polarizer, and an output coupler to form a compound cavity. This method is vibration insensitive, thermal expansion effects are minimal, and the system has a frequency pull in range of 443.2 GHz (9A). Our technique is based on the Faraday anomalous dispersion optical filter. This method has potential applications in optical communication, remote sensing, and pumping laser excited optical filters. We present the first theoretical model for the FADOT and compare the calculations to our experimental results.

  13. Dispersed Fringe Sensing Analysis - DFSA

    Science.gov (United States)

    Sigrist, Norbert; Shi, Fang; Redding, David C.; Basinger, Scott A.; Ohara, Catherine M.; Seo, Byoung-Joon; Bikkannavar, Siddarayappa A.; Spechler, Joshua A.

    2012-01-01

    Dispersed Fringe Sensing (DFS) is a technique for measuring and phasing segmented telescope mirrors using a dispersed broadband light image. DFS is capable of breaking the monochromatic light ambiguity, measuring absolute piston errors between segments of large segmented primary mirrors to tens of nanometers accuracy over a range of 100 micrometers or more. The DFSA software tool analyzes DFS images to extract DFS encoded segment piston errors, which can be used to measure piston distances between primary mirror segments of ground and space telescopes. This information is necessary to control mirror segments to establish a smooth, continuous primary figure needed to achieve high optical quality. The DFSA tool is versatile, allowing precise piston measurements from a variety of different optical configurations. DFSA technology may be used for measuring wavefront pistons from sub-apertures defined by adjacent segments (such as Keck Telescope), or from separated sub-apertures used for testing large optical systems (such as sub-aperture wavefront testing for large primary mirrors using auto-collimating flats). An experimental demonstration of the coarse-phasing technology with verification of DFSA was performed at the Keck Telescope. DFSA includes image processing, wavelength and source spectral calibration, fringe extraction line determination, dispersed fringe analysis, and wavefront piston sign determination. The code is robust against internal optical system aberrations and against spectral variations of the source. In addition to the DFSA tool, the software package contains a simple but sophisticated MATLAB model to generate dispersed fringe images of optical system configurations in order to quickly estimate the coarse phasing performance given the optical and operational design requirements. Combining MATLAB (a high-level language and interactive environment developed by MathWorks), MACOS (JPL s software package for Modeling and Analysis for Controlled Optical

  14. Hydrodynamic dispersion within porous biofilms

    KAUST Repository

    Davit, Y.

    2013-01-23

    Many microorganisms live within surface-associated consortia, termed biofilms, that can form intricate porous structures interspersed with a network of fluid channels. In such systems, transport phenomena, including flow and advection, regulate various aspects of cell behavior by controlling nutrient supply, evacuation of waste products, and permeation of antimicrobial agents. This study presents multiscale analysis of solute transport in these porous biofilms. We start our analysis with a channel-scale description of mass transport and use the method of volume averaging to derive a set of homogenized equations at the biofilm-scale in the case where the width of the channels is significantly smaller than the thickness of the biofilm. We show that solute transport may be described via two coupled partial differential equations or telegrapher\\'s equations for the averaged concentrations. These models are particularly relevant for chemicals, such as some antimicrobial agents, that penetrate cell clusters very slowly. In most cases, especially for nutrients, solute penetration is faster, and transport can be described via an advection-dispersion equation. In this simpler case, the effective diffusion is characterized by a second-order tensor whose components depend on (1) the topology of the channels\\' network; (2) the solute\\'s diffusion coefficients in the fluid and the cell clusters; (3) hydrodynamic dispersion effects; and (4) an additional dispersion term intrinsic to the two-phase configuration. Although solute transport in biofilms is commonly thought to be diffusion dominated, this analysis shows that hydrodynamic dispersion effects may significantly contribute to transport. © 2013 American Physical Society.

  15. Dispersion of Bed Load Particles

    OpenAIRE

    SAWAI, Kenji

    1987-01-01

    The motion of bed load particles is so irregular that they disperse remarkably with time.In this study, some flume tests using painted tracer particles were carried out, in which thedispersive property of tracers changed variously with sediment feed rate.In analysing this process, a stochastic simulation model is proposed where it is discussedabout the degree of exposure of individual particle near the bed surface and about the variationof its pick up rate. The exponential distribution of ste...

  16. Faraday anomalous dispersion optical filters

    Science.gov (United States)

    Shay, T. M.; Yin, B.; Alvarez, L. S.

    1993-01-01

    The effect of Faraday anomalous dispersion optical filters on infrared and blue transitions of some alkali atoms is calculated. A composite system is designed to further increase the background noise rejection. The measured results of the solar background rejection and image quality through the filter are presented. The results show that the filter may provide high transmission and high background noise rejection with excellent image quality.

  17. Correcting slightly less simple movements

    Directory of Open Access Journals (Sweden)

    M.P. Aivar

    2005-01-01

    Full Text Available Many studies have analysed how goal directed movements are corrected in response to changes in the properties of the target. However, only simple movements to single targets have been used in those studies, so little is known about movement corrections under more complex situations. Evidence from studies that ask for movements to several targets in sequence suggests that whole sequences of movements are planned together. Planning related segments of a movement together makes it possible to optimise the whole sequence, but it means that some parts are planned quite long in advance, so that it is likely that they will have to be modified. In the present study we examined how people respond to changes that occur while they are moving to the first target of a sequence. Subjects moved a stylus across a digitising tablet. They moved from a specified starting point to two targets in succession. The first of these targets was always at the same position but it could have one of two sizes. The second target could be in one of two different positions and its size was different in each case. On some trials the first target changed size, and on some others the second target changed size and position, as soon as the subject started to move. When the size of the first target changed the subjects slowed down the first segment of their movements. Even the peak velocity, which was only about 150 ms after the change in size, was lower. Beside this fast response to the change itself, the dwell time at the first target was also affected: its duration increased after the change. Changing the size and position of the second target did not influence the first segment of the movement, but also increased the dwell time. The dwell time was much longer for a small target, irrespective of its initial size. If subjects knew in advance which target could change, they moved faster than if they did not know which could change. Taken together, these

  18. Philopatry and dispersal patterns in tiger (Panthera tigris).

    Science.gov (United States)

    Gour, Digpal Singh; Bhagavatula, Jyotsna; Bhavanishankar, Maradani; Reddy, Patlolla Anuradha; Gupta, Jaya A; Sarkar, Mriganka Shekhar; Hussain, Shaik Mohammed; Harika, Segu; Gulia, Ravinder; Shivaji, Sisinthy

    2013-01-01

    Tiger populations are dwindling rapidly making it increasingly difficult to study their dispersal and mating behaviour in the wild, more so tiger being a secretive and solitary carnivore. We used non-invasively obtained genetic data to establish the presence of 28 tigers, 22 females and 6 males, within the core area of Pench tiger reserve, Madhya Pradesh. This data was evaluated along with spatial autocorrelation and relatedness analyses to understand patterns of dispersal and philopatry in tigers within this well-managed and healthy tiger habitat in India. We established male-biased dispersal and female philopatry in tigers and reiterated this finding with multiple analyses. Females show positive correlation up to 7 kms (which corresponds to an area of approximately 160 km(2)) however this correlation is significantly positive only upto 4 kms, or 50 km(2) (r  = 0.129, ptigers in the world, this study will help us understand tiger behavior and movement. Our findings also have important implications for better management of habitats and interconnecting corridors to save this charismatic species.

  19. Reading the landscape: Legible environments and hominin dispersals.

    Science.gov (United States)

    Guiducci, Dario; Burke, Ariane

    2016-05-06

    Wayfinding, or the ability to plan and navigate a course over the landscape, is a subject of investigation in geography, neurophysiology, psychology, urban planning, and landscape design. With the prevalence of GPS-assisted navigation systems, or "wayfinders," computer scientists are also increasingly interested in understanding how people plan their movements and guide others. However, the importance of wayfinding as a process that regulates human mobility has only recently been incorporated into archeological research design. Hominin groups were able to disperse widely during the course of prehistory. The scope of these dispersals speaks to the innate navigation abilities of hominins. Their long-term success must have depended on an ability to communicate spatial information effectively. Here, we consider the extent to which some landscapes may have been more conducive to wayfinding than others. We also describe a tool we have created for quantifying landscape legibility (sensu Gollege), a complex and under-explored concept in archeology, with a view to investigating the impact of landscape structure on human wayfinding and thus, patterns of dispersal during prehistory. To this end, we have developed a method for quantifying legibility using a Geographic Information System (GIS) and apply it to a test case in prehistoric Iberia. © 2016 Wiley Periodicals, Inc.

  20. Dispersive stresses in wind farms

    Science.gov (United States)

    Segalini, Antonio; Braunbehrens, Robert; Hyvarinen, Ann

    2017-11-01

    One of the most famous models of wind farms is provided by the assumption that the farm can be approximated as a horizontally-homogeneous forest canopy with vertically-varying force intensity. By means of this approximation, the flow-motion equations become drastically simpler, as many of the three-dimensional effects are gone. However, the application of the horizontal average operator to the RANS equations leads to the appearance of new transport terms (called dispersive stresses) originating from the horizontal (small-scale) variation of the mean velocity field. Since these terms are related to the individual turbine signature, they are expected to vanish outside the roughness sublayer, providing a definition for the latter. In the present work, an assessment of the dispersive stresses is performed by means of a wake-model approach and through the linearised code ORFEUS developed at KTH. Both approaches are very fast and enable the characterization of a large number of wind-farm layouts. The dispersive stress tensor and its effect on the turbulence closure models are investigated, providing guidelines for those simulations where it is impossible to resolve the farm at a turbine scale due to grid requirements (as, for instance, mesoscale simulations).

  1. Improving practical atmospheric dispersion models

    International Nuclear Information System (INIS)

    Hunt, J.C.R.; Hudson, B.; Thomson, D.J.

    1992-01-01

    The new generation of practical atmospheric dispersion model (for short range ≤ 30 km) are based on dispersion science and boundary layer meteorology which have widespread international acceptance. In addition, recent improvements in computer skills and the widespread availability of small powerful computers make it possible to have new regulatory models which are more complex than the previous generation which were based on charts and simple formulae. This paper describes the basis of these models and how they have developed. Such models are needed to satisfy the urgent public demand for sound, justifiable and consistent environmental decisions. For example, it is preferable that the same models are used to simulate dispersion in different industries; in many countries at present different models are used for emissions from nuclear and fossil fuel power stations. The models should not be so simple as to be suspect but neither should they be too complex for widespread use; for example, at public inquiries in Germany, where simple models are mandatory, it is becoming usual to cite the results from highly complex computational models because the simple models are not credible. This paper is written in a schematic style with an emphasis on tables and diagrams. (au) (22 refs.)

  2. Dispersion relations in loop calculations

    International Nuclear Information System (INIS)

    Kniehl, B.A.

    1996-01-01

    These lecture notes give a pedagogical introduction to the use of dispersion relations in loop calculations. We first derive dispersion relations which allow us to recover the real part of a physical amplitude from the knowledge of its absorptive part along the branch cut. In perturbative calculations, the latter may be constructed by means of Cutkosky's rule, which is briefly discussed. For illustration, we apply this procedure at one loop to the photon vacuum-polarization function induced by leptons as well as to the γf anti-f vertex form factor generated by the exchange of a massive vector boson between the two fermion legs. We also show how the hadronic contribution to the photon vacuum polarization may be extracted from the total cross section of hadron production in e + e - annihilation measured as a function of energy. Finally, we outline the application of dispersive techniques at the two-loop level, considering as an example the bosonic decay width of a high-mass Higgs boson. (author)

  3. Reciprocal modulation of internal and external factors determines individual movements.

    Science.gov (United States)

    Martin, Jodie; van Moorter, Bram; Revilla, Eloy; Blanchard, Pierrick; Dray, Stéphane; Quenette, Pierre-Yves; Allainé, Dominique; Swenson, Jon E

    2013-03-01

    Movement is fundamental to individual and population dynamics, as it allows individuals to meet their basic requirements. Although movement patterns reflect interactions between internal and external factors, only few studies have examined the effects of these factors on movement simultaneously, and they generally focused on particular biological contexts (e.g. dispersal, foraging). However, the relative importance of these factors in driving individual routine movements might reflect a species' potential flexibility to cope with landscape changes and therefore buffer their potential impact on fitness. We used data from GPS collars on Scandinavian brown bears to investigate the relative role of these factors, as well as an additional factor (period of the year) on routine movements at two spatial scales (hourly and daily relocations). As expected, internal factors played a major role in driving movement, compared to external factors at both scales, but its relative importance was greater at a finer scale. In particular, the interaction between reproductive status and period of the year was one of the most influential variables, females being constrained by the movement capacity of their cubs in the first periods of the year. The effect of human disturbance on movement was also greater for females with cubs than for lone females. This study showed how reciprocal modulation of internal and external factors is shaping space use of brown bears. We stress that these factors should be studied simultaneously to avoid the risk of obtaining context-dependent inferences. Moreover, the study of their relative contribution is also highly relevant in the context of multiple-use landscapes, as human activities generally affect the landscape more than they affect the internal states of an individual. Species or individuals with important internal constraints should be less responsive to changes in their environment as they have less freedom from internal constraints and should

  4. A radioisotope study of the dispersion of ferric hydroxide floc in Bass Strait

    International Nuclear Information System (INIS)

    Davison, A.

    1983-01-01

    The dispersion of ferric hydroxide floc in Bass Strait waters adjacent to Burnie, Tasmania, has been investigated using radioisotope tracer techniques. Gold-198 labelled floc was employed to follow the movement of floc produced by dilution of the iron-rich effluent from a titanium dioxide plant. Dispersion was determined under calm and storm conditions. Tidal and wind-driven currents were measured, oscillating wave generated currents were calculated, and lateral and vertical dispersion coefficients were determined. It is concluded that floc disperses episodically during storms. The agglomerated floc remains trapped in a stable seabed layer which spreads slowly at seabed level when wind velocities are less than 15 m s -1 . When wind velocities exceed this level, the wave generated oscillating currents at seabed level, 30 m below the surface, are strong enough to raise the floc into suspension where advective dispersion occurs. Since tidal currents in the area are negligible, the direction of floc movement depends on the direction of the wind-driven current during each storm

  5. Heterotrimeric Kinesin II Is the Microtubule Motor Protein Responsible for Pigment Dispersion in Xenopus Melanophores

    Science.gov (United States)

    Tuma, M. Carolina; Zill, Andrew; Le Bot, Nathalie; Vernos, Isabelle; Gelfand, Vladimir

    1998-01-01

    Melanophores move pigment organelles (melanosomes) from the cell center to the periphery and vice-versa. These bidirectional movements require cytoplasmic microtubules and microfilaments and depend on the function of microtubule motors and a myosin. Earlier we found that melanosomes purified from Xenopus melanophores contain the plus end microtubule motor kinesin II, indicating that it may be involved in dispersion (Rogers, S.L., I.S. Tint, P.C. Fanapour, and V.I. Gelfand. 1997. Proc. Natl. Acad. Sci. USA. 94: 3720–3725). Here, we generated a dominant-negative construct encoding green fluorescent protein fused to the stalk-tail region of Xenopus kinesin-like protein 3 (Xklp3), the 95-kD motor subunit of Xenopus kinesin II, and introduced it into melanophores. Overexpression of the fusion protein inhibited pigment dispersion but had no effect on aggregation. To control for the specificity of this effect, we studied the kinesin-dependent movement of lysosomes. Neither dispersion of lysosomes in acidic conditions nor their clustering under alkaline conditions was affected by the mutant Xklp3. Furthermore, microinjection of melanophores with SUK4, a function-blocking kinesin antibody, inhibited dispersion of lysosomes but had no effect on melanosome transport. We conclude that melanosome dispersion is powered by kinesin II and not by conventional kinesin. This paper demonstrates that kinesin II moves membrane-bound organelles. PMID:9852150

  6. Chromatic Dispersion Estimation in Digital Coherent Receivers

    DEFF Research Database (Denmark)

    Soriano, Ruben Andres; Hauske, Fabian N.; Guerrero Gonzalez, Neil

    2011-01-01

    Polarization-diverse coherent demodulation allows to compensate large values of accumulated linear distortion by digital signal processing. In particular, in uncompensated links without optical dispersion compensation, the parameter of the residual chromatic dispersion (CD) is vital to set...

  7. Potential of largemouth bass as vectors of 137Cs dispersal

    International Nuclear Information System (INIS)

    Paller, M.H.; Fletcher, D.E.; Jones, T.; Dyer, S.A.; Isely, J.J.; Littrell, J.W.

    2005-01-01

    We conducted a radio telemetry study on the movements of potentially contaminated largemouth bass between Steel Creek, a restricted access 137 Cs contaminated stream on the Savannah River Site (located in South Carolina, USA), and the publicly accessible Savannah River. Largemouth bass were relatively mobile in lower Steel Creek and the portion of the Savannah River near Steel Creek, and there was considerable movement between these two habitats. Largemouth bass had home ranges of about 500 linear meters of shoreline in the Savannah River but sometimes moved long distances. Such movements occurred primarily during the spawning season, largely upstream, and increased when water levels were changing or elevated. However, approximately 90% of the largemouth bass observations were within 10 km of Steel Creek. The total quantity of 137 Cs transported into the Savannah River by largemouth bass was much less than transported by water and suspended sediments discharged from Steel Creek. We conclude that largemouth bass from the Savannah River Site are unlikely to be responsible for long distance dispersal of substantial radiological contamination in the Savannah River

  8. Statistical Physics of Colloidal Dispersions.

    Science.gov (United States)

    Canessa, E.

    Available from UMI in association with The British Library. Requires signed TDF. This thesis is concerned with the equilibrium statistical mechanics of colloidal dispersions which represent useful model systems for the study of condensed matter physics; namely, charge stabilized colloidal dispersions and polymer stabilized colloidal dispersions. A one-component macroparticle approach is adopted in order to treat the macroscopic and microscopic properties of these systems in a simple and comprehensive manner. The thesis opens with the description of the nature of the colloidal state before reviewing some basic definitions and theory in Chapter II. In Chapter III a variational theory of phase equilibria based on the Gibbs-Bogolyobov inequality is applied to sterically stabilized colloidal dispersions. Hard spheres are chosen as the reference system for the disordered phases while an Einstein model is used for the ordered phases. The new choice of pair potential, taken for mathematical convenience, is a superposition of two Yukawa functions. By matching a double Yukawa potential to the van der Waals attractive potential at different temperatures and introducing a purely temperature dependent coefficient to the repulsive part, a rich variety of observed phase separation phenomena is qualitatively described. The behaviour of the potential is found to be consistent with a small decrease of the polymer layer thickness with increasing temperature. Using the same concept of a collapse transition the non-monotonic second virial coefficient is also explained and quantified. It is shown that a reduction of the effective macroparticle diameter with increasing temperature can only be partially examined from the point of view of a (binary-) polymer solution theory. This chapter concludes with the description of the observed, reversible, depletion flocculation behaviour. This is accomplished by using the variational formalism and by invoking the double Yukawa potential to allow

  9. A random walk description of individual animal movement accounting for periods of rest

    Science.gov (United States)

    Tilles, Paulo F. C.; Petrovskii, Sergei V.; Natti, Paulo L.

    2016-11-01

    Animals do not move all the time but alternate the period of actual movement (foraging) with periods of rest (e.g. eating or sleeping). Although the existence of rest times is widely acknowledged in the literature and has even become a focus of increased attention recently, the theoretical approaches to describe animal movement by calculating the dispersal kernel and/or the mean squared displacement (MSD) rarely take rests into account. In this study, we aim to bridge this gap. We consider a composite stochastic process where the periods of active dispersal or `bouts' (described by a certain baseline probability density function (pdf) of animal dispersal) alternate with periods of immobility. For this process, we derive a general equation that determines the pdf of this composite movement. The equation is analysed in detail in two special but important cases such as the standard Brownian motion described by a Gaussian kernel and the Levy flight described by a Cauchy distribution. For the Brownian motion, we show that in the large-time asymptotics the effect of rests results in a rescaling of the diffusion coefficient. The movement occurs as a subdiffusive transition between the two diffusive asymptotics. Interestingly, the Levy flight case shows similar properties, which indicates a certain universality of our findings.

  10. On street observations of particulate matter movement and dispersion due to traffic on an urban road

    Science.gov (United States)

    Patra, Aditya; Colvile, Roy; Arnold, Samantha; Bowen, Emma; Shallcross, Dudley; Martin, Damien; Price, Catheryn; Tate, James; ApSimon, Helen; Robins, Alan

    Empirical models for particulate matter emissions from paved road surfaces have been criticised for their lack of realism and accuracy. To support the development of a less empirical model, a study was conducted in a busy street at the DAPPLE site in Central London to understand the processes and to identify important parameters that influence emission from paved roads. Ordinary road gritting salt was applied to the road and the particulate matter entering the air at near-road surface level was monitored using optical particle counters. The grit acted as a tracer. The grit moved rapidly along the road in the direction of traffic flow. Build-up of material at the kerb indicated material being thrown across the road by the traffic. Coarser particles were resuspended faster than the finer ones. A clear decay profile was seen in the case of particles larger than 2μm; particles smaller than 2μm did not show any decay pattern during the experiment duration. Grinding of material appears to control the reservoir of fine particles on the road surface. The amount of material resuspended by traffic is about 30% less than those removed along the road and a factor of 6 higher than the amount removed across the road. Resuspension accounts for 40% of the total material removed from a road segment and 70% of the material removed together along and across the road. On average a single vehicle pass removes 0.08% of material present on a road segment at that instant. The calculation scheme is obtained from a short-duration study and therefore further studies of long duration involving varying road geometry and different traffic and meteorological condition need to be carried out before applying parameter estimates presented in this paper.

  11. Dispersion properties of photonic crystal fibres

    DEFF Research Database (Denmark)

    Bjarklev, Anders Overgaard; Broeng, Jes; Dridi, Kim

    1998-01-01

    Approximate dispersion and bending properties of all-silica two-dimensional photonic crystal fibres are characterised by the combination of an effective-index model and classical analysis tools for optical fibres. We believe for the first time to have predicted the dispersion properties of photonic...... crystal fibres. The results strongly indicate that these fibres have potential applications as dispersion managing components...

  12. Catchment Dispersion Mechanisms in an Urban Context

    Science.gov (United States)

    Gironas, J. A.; Mejia, A.; Rossel, F.; Rinaldo, A.; Rodriguez, F.

    2014-12-01

    Dispersion mechanisms have been examined in-depth in natural catchments in previous studies. However, these dispersion mechanisms have been studied little in urban catchments, where artificial transport elements and morphological arrangements are expected to modify travel times and mobilize excess rainfall from spatially distributed impervious sites. Thus, these features can modify the variance of the catchment's travel times and hence the total dispersion. This work quantifies the dispersion mechanisms in an urban catchment using the theory of transport by travel times as represented by the Urban Morpho-climatic Instantaneous Unit Hydrograph (U-McIUH) model. This model computes travel times based on kinematic wave theory and accounts explicitly for the path heterogeneities and altered connectivity patterns characteristic of an urban drainage network. The analysis is illustrated using the Aubinière urban catchment (France) as a case study. We found that kinematic dispersion is dominant for small rainfall intensities, whereas geomorphologic dispersion becomes more dominant for larger intensities. The total dispersion scales with the drainage area in a power law fashion. The kinematic dispersion is dominant across spatial scales up to a threshold of approximately 2-3 km2, after which the geomorphologic dispersion becomes more dominant. Overall, overland flow is responsible for most of the dispersion, while conduits tend to counteract the increase of the geomorphologic dispersion with a negative kinematic dispersion. Further studies with other catchments are needed to assess whether the latter is a general feature of urban drainage networks.

  13. Dispersion of coupled mode-gap cavities

    NARCIS (Netherlands)

    Lian, Jin; Sokolov, Sergei; Yuce, E.; Combrie, S.; de Rossi, A.; Mosk, Allard

    2015-01-01

    The dispersion of a coupled resonator optical waveguide made of photonic crystal mode-gap cavities is pronouncedly asymmetric. This asymmetry cannot be explained by the standard tight binding model. We show that the fundamental cause of the asymmetric dispersion is the inherent dispersive cavity

  14. Characterization of finite spaces having dispersion points

    International Nuclear Information System (INIS)

    Al-Bsoul, A. T

    1997-01-01

    In this paper we shall characterize the finite spaces having dispersion points. Also, we prove that the dispersion point of a finite space with a dispersion points fixed under all non constant continuous functions which answers the question raised by J. C obb and W. Voxman in 1980 affirmatively for finite space. Some open problems are given. (author). 16 refs

  15. Delayed Auditory Feedback and Movement

    Science.gov (United States)

    Pfordresher, Peter Q.; Dalla Bella, Simone

    2011-01-01

    It is well known that timing of rhythm production is disrupted by delayed auditory feedback (DAF), and that disruption varies with delay length. We tested the hypothesis that disruption depends on the state of the movement trajectory at the onset of DAF. Participants tapped isochronous rhythms at a rate specified by a metronome while hearing DAF…

  16. Noun Phrase Structure and Movement

    DEFF Research Database (Denmark)

    Wood, Johanna; Vikner, Sten

    2011-01-01

    /solch to follow the article. We discuss two possible syntactic derivations, predicate raising (e.g. Corver 1998, Bennis, Corver & den Dikken 1998) and XP movement from an attributive adjective position within the nominal (e.g. Matushansky 2002). The analysis links up with the morphological agreement facts...

  17. Ketotic hyperglycemia with movement disorder

    Directory of Open Access Journals (Sweden)

    Disha Awasthi

    2012-01-01

    Full Text Available Chorea, hemichorea-hemiballismus and severe partial seizures may be the presenting features of nonketotic hyperglycemia in older adults with type 2 diabetes, but cases in young adults with type 1 diabetes are rare. We hereby report a very rare case of diabetic ketosis with movement disorder in a young patient.

  18. Population consequences of aggregative movement

    Science.gov (United States)

    Peter Turchin

    1989-01-01

    Gregarious behaviour is an important factor influencing survival and reproduction of animals, as well as population interactions. In this paper I develop a model of movement with attraction or repulsion between conspecifics. To facilitate its use in empirical studies, the model is based on experimentally measurable features of individual behaviour.

  19. Actuating movement in refined wearables

    NARCIS (Netherlands)

    Toeters, M.J.; Feijs, L.M.G.

    2014-01-01

    Nowadays it is quite possible to deploy textiles as sensors and avoid traditional hard sensors. Actuation (movement) turns out more difficult. It is advantageous to combine sensing and actuation, similar to ecological perception theory. Although several actuators are known: SMA, voice coil, motors,

  20. THE INTERNATIONAL WALDORF SCHOOL MOVEMENT.

    Science.gov (United States)

    VON BARAVALLE, HERMANN

    AN HISTORICAL REVIEW OF THE WALDORF SCHOOL PLAN TRACES THE MOVEMENT FROM ITS FOUNDING IN STUTTGART, GERMANY IN 1919, BY THE WALDORF ASTORIA COMPANY AND UNDER THE DIRECTION OF RUDOLF STEINER, TO ITS INTRODUCTION INTO SWITZERLAND, OTHER EUROPEAN COUNTRIES, THE AMERICAS, AUSTRALIA, NEW ZEALAND, AND SOUTH AFRICA, A TOTAL OF 175 SCHOOLS AS OF 1963. THE…

  1. Enhanced Gravitational Drainage of Crude Oil Through Alabama Beach Sand Caused by the Dispersant Corexit 9500A

    Science.gov (United States)

    Steffy, D. A.; Nichols, A.; Hobbs, K.

    2017-12-01

    Oil spill material released by the 2010 Deepwater Horizon accident contaminated a majority of the 60 miles of Alabama coastline. In response to the oil spill, BP sprayed a dispersant, Corexit 9500A, as an initial remediation effort. An unforeseen impact of the saltwater-dispersant mixture includes the mobilization of oil-spilled material into the underlying beach sand. This study investigated the effect of the dispersant to promote gravitational drainage by measuring the physical characteristics of the sand, saltwater, crude oil, and the dispersant solution. The saltwater-dispersant mixture promoted the downward movement of oil mass 20 times greater extent than just saltwater. These tests are meant to simulate spill material on the beach being exposed to a low-energy, 1-meter mixed tide occurring along the Alabama coastline. A separate test simulated oilwet sand exposed to saltwater and a saltwater-dispersant mixture. The oil-wet sand impeded the vertical movement of saltwater, but allowed a saltwater-dispersant solution to mobilize the oil to migrate downward. The mobilization of oil in this three phase system of saltwater, oil, and air is controlled by: the pressure-saturation profile of the sand; interfacial tension with saltwater; and its surface tension with air.

  2. Cumulative Effects of Barriers on the Movements of Forest Birds

    Directory of Open Access Journals (Sweden)

    Marc Bélisle

    2002-01-01

    Full Text Available Although there is a consensus of opinion that habitat fragmentation has deleterious effects on animal populations, primarily by inhibiting dispersal among remaining patches, there have been few explicit demonstrations of the ways by which degraded habitats actually constrain individual movement. Two impediments are primarily responsible for this paucity: it is difficult to separate the effects of habitat fragmentation (configuration from habitat loss (composition, and conventional measures of fragmented habitats are assumed to be, but probably are not, isotropic. We addressed these limitations by standardizing differences in forest cover in a clearly anisotropic configuration of habitat fragmentation by conducting a homing experiment with three species of forest birds in the Bow Valley of Banff National Park, Canada. Birds were translocated (1.2-3.5  km either parallel or perpendicular to four/five parallel barriers that are assumed to impede the cross-valley travel of forest-dependent animals. Taken together, individuals exhibited longer return times when they were translocated across these barriers, but differences among species suggest a more complex interpretation. A long-distance migrant (Yellow-rumped Warbler, Dendroica coronata behaved as predicted, but a short-distance migrant (Golden-crowned Kinglet, Regulus satrapa was indifferent to barrier configuration. A resident (Red-breasted Nuthatch, Sitta canadensis exhibited longer return times when it was translocated parallel to the barriers. Our results suggest that an anisotropic arrangement of small, open areas in fragmented landscapes can have a cumulative barrier effect on the movement of forest animals, but that both modelers and managers will have to acknowledge potentially counterintuitive differences among species to predict the effect that these may have on individual movement and, ultimately, dispersal.

  3. Normal-dispersion microresonator Kerr frequency combs

    Directory of Open Access Journals (Sweden)

    Xue Xiaoxiao

    2016-06-01

    Full Text Available Optical microresonator-based Kerr frequency comb generation has developed into a hot research area in the past decade. Microresonator combs are promising for portable applications due to their potential for chip-level integration and low power consumption. According to the group velocity dispersion of the microresonator employed, research in this field may be classified into two categories: the anomalous dispersion regime and the normal dispersion regime. In this paper, we discuss the physics of Kerr comb generation in the normal dispersion regime and review recent experimental advances. The potential advantages and future directions of normal dispersion combs are also discussed.

  4. Eye movements of patients with tunnel vision while walking.

    Science.gov (United States)

    Vargas-Martín, Fernando; Peli, Eli

    2006-12-01

    To determine how severe peripheral field loss (PFL) affects the dispersion of eye movements relative to the head in patients walking in real environments. This information should help to define the visual field and clearance requirements for head-mounted mobility visual aids. Eye positions relative to the head were recorded in five patients with retinitis pigmentosa who had less than 15 degrees of visual field and in three normally sighted people, each walking in varied environments for more than 30 minutes. The eye-position recorder was made portable by modifying a head-mounted system (ISCAN, Burlington, MA). Custom data processing was implemented, to reject unreliable data. Sample standard deviations of eye position (dispersion) were compared across subject groups and environments. The patients with PFL exhibited narrower horizontal eye-position dispersions than did the normally sighted subjects (9.4 degrees vs. 14.2 degrees , P vision information. Their horizontal scanning was actually reduced, possibly because of lack of peripheral stimulation. The results suggest that a field of view as wide as 40 degrees may be needed for closed (immersive) head-mounted mobility aids, whereas a much narrower display, perhaps as narrow as 20 degrees , may be sufficient with an open design.

  5. Dispersed publication of editorial research

    DEFF Research Database (Denmark)

    Rosenberg, Jacob; Pommergaard, Hans-Christian; Vinther, Siri

    2015-01-01

    INTRODUCTION: There seems to be no dedicated journals available for publication of editorial research in the biomedical sciences; that is research into editorial or publication process issues involving the scientific approach to writing, reviewing, editing and publishing. It is unknown where papers...... journals with a median of one article per journal (range: 1-17). CONCLUSION: The publication of papers on editorial research seems to be dispersed. In order to increase the visibility of this research field, it may be reasonable to establish well-defined platforms such as dedicated journals or journal...

  6. A nonlocal inhomogeneous dispersal process

    Science.gov (United States)

    Cortázar, C.; Coville, J.; Elgueta, M.; Martínez, S.

    This article in devoted to the study of the nonlocal dispersal equation u(x,t)=∫R J({x-y}/{g(y)}){u(y,t)}/{g(y)} dy-u(x,t) in R×[0,∞), and its stationary counterpart. We prove global existence for the initial value problem, and under suitable hypothesis on g and J, we prove that positive bounded stationary solutions exist. We also analyze the asymptotic behavior of the finite mass solutions as t→∞, showing that they converge locally to zero.

  7. Taylor dispersion on a fractal

    International Nuclear Information System (INIS)

    Mazo, R.M.

    1998-01-01

    Taylor dispersion is the greatly enhanced diffusion in the direction of a fluid flow caused by ordinary diffusion in directions orthogonal to the flow. It is essential that the system be bounded in space in the directions orthogonal to the flow. We investigate the situation where the medium through which the flow occurs has fractal properties so that diffusion in the orthogonal directions is anomalous and non-Fickian. The effective diffusion in the flow direction remains normal; its width grows proportionally with the time. However, the proportionality constant depends on the fractal dimension of the medium as well as its walk dimension. (author)

  8. Early Christian movements: Jesus movements and the renewal of Israel

    Directory of Open Access Journals (Sweden)

    Richard A. Horsley

    2006-10-01

    Full Text Available This article investigates the origins and development of the earliest Jesus movements within the context of persistent conflict between the Judean and Galilean peasantry and their Jerusalem and Roman rulers. It explores the prominence of popular prophetic and messianic movements and shows how the earliest movements that formed in response to Jesus’ mission exhibit similar features and patterns. Jesus is not treated as separate from social roles and political-economic relationships. Viewing Jesus against the background of village communities in which people lived, the Gospels are understood as genuine communication with other people in historical social contexts. The article argues that the net effect of these interrelated factors of theologically determined New Testament interpretation is a combination of assumptions and procedures that would be unacceptable in the regular investigation of history. Another version of the essay was published in Horsley, Richard A (ed, A people’s history of Christianity, Volume 1: Christian origins, 23-46. Minneapolis, MN: Fortress.

  9. Extragalactic dispersion measures of fast radio bursts

    International Nuclear Information System (INIS)

    Xu, Jun; Han, J. L.

    2015-01-01

    Fast radio bursts show large dispersion measures, much larger than the Galactic dispersion measure foreground. Therefore, they evidently have an extragalactic origin. We investigate possible contributions to the dispersion measure from host galaxies. We simulate the spatial distribution of fast radio bursts and calculate the dispersion measures along the sightlines from fast radio bursts to the edge of host galaxies by using the scaled NE2001 model for thermal electron density distributions. We find that contributions to the dispersion measure of fast radio bursts from the host galaxy follow a skew Gaussian distribution. The peak and the width at half maximum of the dispersion measure distribution increase with the inclination angle of a spiral galaxy, to large values when the inclination angle is over 70°. The largest dispersion measure produced by an edge-on spiral galaxy can reach a few thousand pc cm −3 , while the dispersion measures from dwarf galaxies and elliptical galaxies have a maximum of only a few tens of pc cm −3 . Notice, however, that additional dispersion measures of tens to hundreds of pc cm −3 can be produced by high density clumps in host galaxies. Simulations that include dispersion measure contributions from the Large Magellanic Cloud and the Andromeda Galaxy are shown as examples to demonstrate how to extract the dispersion measure from the intergalactic medium. (paper)

  10. Preliminary Studies of the Field Movement of the Olive Fruit Fly (Dacus Oleae Gmel,) by Labelling a Natural Population with Radioactive Phosphorus (P{sup 32}); Etudes preijminaires sur les deplacements de la mouche de l'olive (Dacus Oleae Gmel. ) par marquage d'une population naturelle au radiophosphore ({sup 32}P); Predvaritel'noe issledovanie polevogo peremeshcheniya olivkovoj fruktovoj mukhi (Dacus Oleae Gmel.) posredstvom mecheniya estestvennoj populyatsii radioaktivnym fosforom (P{sup 32}).; Estudio preliminar de la dispersion de moscas del ouvo (Dacus Oleae Gmel. ) mediante la marcacion de poblaciones naturales con {sup 32}p.

    Energy Technology Data Exchange (ETDEWEB)

    Pelekassis, Constantine E.D.; Mourikos, P. A.; Bantzios, D. N. [Economic Entomology Laboratory, Benaki Phytopathological Institute, Athens (Greece)

    1963-09-15

    Preliminary trials were conducted to obtain the first data on the field movement of the olive fruit fly, Dacus oleae Gmel. These studies were carried out in the olive-growing area at Rovies, Evvia, Greece, during the autumn of 1961, when the maximum adult fly activity usually occurs. A mixture of radioactive P{sup 32} of H{sub 3}P{sup 32}O{sub 4} in HCl and hydrolysate protein, Staley No. 7, was prepared for labelling the naturally occurring adult fly population. Twigs of 30 olive trees which were selected in a semi-mountainous olive orchard at Rovies were treated with the P{sup 32} bait solution on 14 October 1961. Five hundred McPhail traps, containing 3% of diammonium phosphate as a lure, were used for the collection of flies. Traps were distributed in the olive groves of the entire area at Rovies and also in the adjacent areas (fewest or olive groves) up to a distance of 10 km from the treated trees. A total of 350 tagged flies of both sexes were collected in 48 traps during 15 counts of traps made between 15 October and 18 November. Labelled flies which were caught from 1 to 35 days after treatment represented 2.8% of the total number of flies collected in 48 traps, or 0.15% of the total number of flies caught in 298 traps in the entire area at Rovies. A proportion of 73% of the tagged flies were trapped within the first ten-day period following treatment. Labelled flies were found as far as 4300 m (maximum of dispersal) from the labelling station. Radioactivity of tagged flies ranged between 258 and 9549 counts/min per fly (background radiation 8-21 counts/min). These preliminary trials have confirmed a more or less continuous local movement (dispersal) o f flies from the semi-mountainous grove to the adjacent plains or to the coastal olive groves at Rovies from the north to south. Long-distance movement (migration) of Dacus flies to other areas has not been observed. Pine woods appear to act as a barrier to die movement of Dacus oleae adults. (author

  11. Eye movements during listening reveal spontaneous grammatical processing.

    Science.gov (United States)

    Huette, Stephanie; Winter, Bodo; Matlock, Teenie; Ardell, David H; Spivey, Michael

    2014-01-01

    Recent research using eye-tracking typically relies on constrained visual contexts in particular goal-oriented contexts, viewing a small array of objects on a computer screen and performing some overt decision or identification. Eyetracking paradigms that use pictures as a measure of word or sentence comprehension are sometimes touted as ecologically invalid because pictures and explicit tasks are not always present during language comprehension. This study compared the comprehension of sentences with two different grammatical forms: the past progressive (e.g., was walking), which emphasizes the ongoing nature of actions, and the simple past (e.g., walked), which emphasizes the end-state of an action. The results showed that the distribution and timing of eye movements mirrors the underlying conceptual structure of this linguistic difference in the absence of any visual stimuli or task constraint: Fixations were shorter and saccades were more dispersed across the screen, as if thinking about more dynamic events when listening to the past progressive stories. Thus, eye movement data suggest that visual inputs or an explicit task are unnecessary to solicit analog representations of features such as movement, that could be a key perceptual component to grammatical comprehension.

  12. Eye movements during listening reveal spontaneous grammatical processing

    Directory of Open Access Journals (Sweden)

    Stephanie eHuette

    2014-05-01

    Full Text Available Recent research using eye-tracking typically relies on constrained visual contexts in particular goal-oriented contexts, viewing a small array of objects on a computer screen and performing some overt decision or identification. Eyetracking paradigms that use pictures as a measure of word or sentence comprehension are sometimes touted as ecologically invalid because pictures and explicit tasks are not always present during language comprehension. This study compared the comprehension of sentences with two different grammatical forms: the past progressive (e.g., was walking, which emphasizes the ongoing nature of actions, and the simple past (e.g., walked, which emphasizes the end-state of an action. The results showed that the distribution and timing of eye movements mirrors the underlying conceptual structure of this linguistic difference in the absence of any visual stimuli or task constraint: Fixations were shorter and saccades were more dispersed across the screen, as if thinking about more dynamic events when listening to the past progressive stories. Thus, eye movement data suggest that visual inputs or an explicit task are unnecessary to solicit analogue representations of features such as movement, that could be a key perceptual component to grammatical comprehension.

  13. Eye-movements and ongoing task processing.

    Science.gov (United States)

    Burke, David T; Meleger, Alec; Schneider, Jeffrey C; Snyder, Jim; Dorvlo, Atsu S S; Al-Adawi, Samir

    2003-06-01

    This study tests the relation between eye-movements and thought processing. Subjects were given specific modality tasks (visual, gustatory, kinesthetic) and assessed on whether they responded with distinct eye-movements. Some subjects' eye-movements reflected ongoing thought processing. Instead of a universal pattern, as suggested by the neurolinguistic programming hypothesis, this study yielded subject-specific idiosyncratic eye-movements across all modalities. Included is a discussion of the neurolinguistic programming hypothesis regarding eye-movements and its implications for the eye-movement desensitization and reprocessing theory.

  14. Introduction to nonlinear dispersive equations

    CERN Document Server

    Linares, Felipe

    2015-01-01

    This textbook introduces the well-posedness theory for initial-value problems of nonlinear, dispersive partial differential equations, with special focus on two key models, the Korteweg–de Vries equation and the nonlinear Schrödinger equation. A concise and self-contained treatment of background material (the Fourier transform, interpolation theory, Sobolev spaces, and the linear Schrödinger equation) prepares the reader to understand the main topics covered: the initial-value problem for the nonlinear Schrödinger equation and the generalized Korteweg–de Vries equation, properties of their solutions, and a survey of general classes of nonlinear dispersive equations of physical and mathematical significance. Each chapter ends with an expert account of recent developments and open problems, as well as exercises. The final chapter gives a detailed exposition of local well-posedness for the nonlinear Schrödinger equation, taking the reader to the forefront of recent research. The second edition of Introdu...

  15. Dispersivity in heterogeneous permeable media

    International Nuclear Information System (INIS)

    Chesnut, D.A.

    1994-01-01

    When one fluid displaces another through a one-dimensional porous medium, the composition changes from pure displacing fluid at the inlet to pure displaced fluid some distance downstream. The distance over which an arbitrary percentage of this change occurs is defined as the mixing zone length, which increases with increasing average distance traveled by the displacement front. For continuous injection, the mixing zone size can be determined from a breakthrough curve as the time required for the effluent displacing fluid concentration to change from, say, 10% to 90%. In classical dispersion theory, the mixing zone grows in proportion to the square root of the mean distance traveled, or, equivalently, to the square root of the mean breakthrough time. In a multi-dimensional heterogeneous medium, especially at field scales, the size of the mixing zone grows almost linearly with mean distance or travel time. If an observed breakthrough curve is forced to fit the, clinical theory, the resulting effective dispersivity, instead of being constant, also increases almost linearly with the spatial or temporal scale of the problem. This occurs because the heterogeneity in flow properties creates a corresponding velocity distribution along the different flow pathways from the inlet to the outlet of the system. Mixing occurs mostly at the outlet, or wherever the fluid is sampled, rather than within the medium. In this paper, we consider the effects. of this behavior on radionuclide or other contaminant migration

  16. Dispersivity in heterogeneous permeable media

    International Nuclear Information System (INIS)

    Chesnut, D.A.

    1994-01-01

    When one fluid displaces another through a one-dimensional porous medium, the composition changes from pure displacing fluid at the inlet to pure displaced fluid some distance downstream. The distance over which an arbitrary percentage (typically 80%) of this change occurs is defined as the mixing zone length, which increases with increasing average distance traveled by the displacement front. Alternatively, for continuous injection, the mixing zone size can be determined from a breakthrough curve as the time required for the effluent displacing fluid concentration to change from, say, 10% to 90%. In classical dispersion theory, the mixing zone grows in proportion to the square root of the mean distance traveled, or, equivalently, to the square root of the mean breakthrough time. In a multi-dimensional heterogeneous medium, especially at field scales, the size of the mixing zone grows almost linearly with mean distance or travel time. If an observed breakthrough curve is forced to fit the classical theory, the resulting effective dispersivity, instead of being constant, also increases almost linearly with the spatial or temporal scale of the problem. This occurs because the heterogeneity in flow properties creates a corresponding velocity distribution along the different flow pathways from the inlet to the outlet of the system. Mixing occurs mostly at the outlet, or wherever the fluid is sampled, rather than within the medium. In this paper, we consider the effects of this behavior on radionuclide or other contaminant migration

  17. Interpatch foraging in honeybees-rational decision making at secondary hubs based upon time and motivation.

    Science.gov (United States)

    Najera, Daniel A; McCullough, Erin L; Jander, Rudolf

    2012-11-01

    For honeybees, Apis mellifera, the hive has been well known to function as a primary decision-making hub, a place from which foragers decide among various directions, distances, and times of day to forage efficiently. Whether foraging honeybees can make similarly complex navigational decisions from locations away from the hive is unknown. To examine whether or not such secondary decision-making hubs exist, we trained bees to forage at four different locations. Specifically, we trained honeybees to first forage to a distal site "CT" 100 m away from the hive; if food was present, they fed and then chose to go home. If food was not present, the honeybees were trained to forage to three auxiliary sites, each at a different time of the day: A in the morning, B at noon, and C in the afternoon. The foragers learned to check site CT for food first and then efficiently depart to the correct location based upon the time of day if there was no food at site CT. Thus, the honeybees were able to cognitively map motivation, time, and five different locations (Hive, CT, A, B, and C) in two spatial dimensions; these are the contents of the cognitive map used by the honeybees here. While at site CT, we verified that the honeybees could choose between 4 different directions (to A, B, C, and the Hive) and thus label it as a secondary decision-making hub. The observed decision making uncovered here is inferred to constitute genuine logical operations, involving a branched structure, based upon the premises of motivational state, and spatiotemporal knowledge.

  18. Soil wetting patterns of vegetation and inter-patches following single and repeated wildfires

    Science.gov (United States)

    González, Óscar; Malvar, Maruxa; van den Elsen, Erik; Hosseini, mohammadreza; Coelho, Celeste; Ritsema, Coen; Bautista, Susana; Keizer, Jan Jacob; Cerdà, Artemi

    2015-04-01

    Although wildfires spread in Mediterranean areas are considered a natural processes, the expected increase in fire frequency has raised concerns about the systems' future resilience (Pausas, 2004). Besides more frequent, future wildfires can become more severe and produce more pronounced changes in topsoil properties, vegetation and litter (Cerdá and Mataix-Solera, 2009). To deal with challenges, the EU funded CASCADE and RECARE projects, which are currently assessing soil threats and tipping-points for land degradation in a climatic gradient across Europe. The present research was developed in Portugal and aims to find relationships between fire frequency and soil wetting patterns following single versus repeated wildfires. In September 2012, a wildfire burnt 3000 ha. of Pine stands and shrub vegetation in the vicinity of Viseu district, North-Central Portugal. Analyses according to the available burnt-area maps (1975-2012), discriminated areas that has been burned 1x (called SD) and 4x (called D) times. In order to evaluate the post-fire soil surface moisture patterns, 6 slopes (3 in SD and 3 in D) were selected and a balanced experimental design with 72 soil moisture sensors (EC5 and GS3, from Decagon devices) was implemented under shrubs (n=18) and on bare (n=18) soil environments, at 2.5 cm and 7.5 cm soil depth each. The spatio-temporal occurrence of soil water repellence (SWR) (Keizer et al., 2008; Prats et al., 2013; Santos et al., 2014) was monthly assessed through the MED test at 2.5 cm and 7.5 cm soil depth into 5 sampling points located at regular distances along a transect running from the top to bottom of a selected slope in SD and D. Automatic and totalize rainfall gauges were also installed across the study area. Preliminary results showed that soil wetting patterns and SWR occurrence differs between SD, D sites and, between soil environment (under shrubs and on bare soil areas). SWR were more pronounced on the SD than in D, affecting soil wetting cycles. Soil moisture content and antecedent rainfall were both correlated with SWR, although insufficient to predict the temporal variations. Antecedent and maximum soil moisture were close related with the SWR status and data analyses showed a top-down breaking mechanism on the SWR Acknowledgements. The research projects CASCADE FP7 (ENV.2011.2.1.4, www.cascade-project.eu) AND RECARE FP7 (n° 603498, http://recare-project.eu/) supported this research. References. Cerdá, A., Mataix-Solera, J., 2009. Incendios forestales en España. Ecosistemas terrestres y suelos. En: Efectos de los incendios forestales sobre los suelos en España. Cerda and Mataix-Solera (eds). Universidad de Valencia, Valencia (España). 529 pp. Keizer, J.J., Doerr, S.H., Malvar, M.C., Prats, S.A., Ferreira, R.S.V., Oñate, M.G., Coelho, C.O.A., Ferreira, A.J.D., 2008. Temporal variation in topsoil water repellency in two recently burnt eucalypt stands in north-central Portugal. Catena 74 (3), 192-204. Pausas, J., 2004. Changes in fire and climate in the eastern Iberian Peninsula (Mediterranean basin). Climatic Change, 63: 330-340. Prats, S.A., Malvar, M., Vieira, D.C.S., McDonald, L., Keizer, J.J. 2013. Effectiveness of hydromulching to reduce runoff and erosion in a recently burnt pine plantation in central Portugal. Land Degradation and Development. DOI: 10.1002/ldr.2236. Santos J.M., Verheijen F.G.A., Wahren F.T., Wahren A., Feger K.H., Bernard-Jannin L., Rial Rivas M.E., Keizer J.J., Nunes J.P. 2014. Soil Water Repellency dynamics in Pine and Eucalypt plantations in Portugal - A high resolution time series. Land Degradation & Development. DOI: 10.1002/ldr.2251.

  19. Zero-gravity movement studies

    Science.gov (United States)

    Badler, N. I.; Fishwick, P.; Taft, N.; Agrawala, M.

    1985-01-01

    The use of computer graphics to simulate the movement of articulated animals and mechanisms has a number of uses ranging over many fields. Human motion simulation systems can be useful in education, medicine, anatomy, physiology, and dance. In biomechanics, computer displays help to understand and analyze performance. Simulations can be used to help understand the effect of external or internal forces. Similarly, zero-gravity simulation systems should provide a means of designing and exploring the capabilities of hypothetical zero-gravity situations before actually carrying out such actions. The advantage of using a simulation of the motion is that one can experiment with variations of a maneuver before attempting to teach it to an individual. The zero-gravity motion simulation problem can be divided into two broad areas: human movement and behavior in zero-gravity, and simulation of articulated mechanisms.

  20. The Geography of Trust and Betrayal: Moral disputes and Late Pleistocene dispersal

    OpenAIRE

    Spikins, Penny

    2015-01-01

    The explanations for a rapid dispersal of modern humans after 100,000 BP remain enigmatic. Populations of modern humans took new routes – crossing significant topographic and environmental barriers, including making major sea crossings, and moving into and through risky and difficult environments. Neither population increase nor ecological changes provide an adequate explanation for a pattern of rapid movement, including leaping into new regions (saltation events). Here it is argued that the ...

  1. Exoskeleton for assisting human movement

    OpenAIRE

    García Armada, Elena; Cestari, Manuel; Sanz Merodio, Daniel; Carrillo, Xavier Alberto

    2015-01-01

    [EN] The invention relates to an exoskeleton for assisting human movement, which can be fitted to the user in terms of dimensions, tension and ranges of joint motion, either manually or automatically. Said exoskeleton can be fitted to the user in the anteroposterior direction in the sagittal plane, with the user in a horizontal or sitting position, without requiring a functional transfer. The exoskeleton has a modular design which is compatible with human biomechanics and reproduces a natural...

  2. Movement of global warming issues

    International Nuclear Information System (INIS)

    Sugiyama, Taishi

    2015-01-01

    This paper summarizes the report of IPCC (Intergovernmental Panel on Climate Change), and the movement of the global warming issues as seen from the United Nations Framework Convention on Climate Change (Conference of the Parties: COP) and the policy discussions in Japan. From the Fifth Assessment Report published by IPCC, it shows the following items: (1) increasing trends of greenhouse effect gas emissions during 1970 and 2010, (2) trends in world's greenhouse effect gas emissions according to income segment, and (3) factor analysis of changes in greenhouse effect gas emissions. Next, it takes up the greenhouse gas emission scenario of IPCC, shows the scenario due to temperature rise pattern, and introduces the assumption of emission reduction due to BECCS. Regarding the 2 deg. scenario that has become a hot topic in international negotiations, it describes the reason for difficulties in its implementation. In addition, as the international trends of global warming, it describes the agreement of numerical targets for emissions at COP3 (Kyoto Conference) and the subsequent movements. Finally, it introduces Japan's measures against global warming, as well as the future movement. (A.O.)

  3. Home range and local movement of small mammals on the Radioactive Waste Management Complex Idaho National Engineering Laboratory Site

    International Nuclear Information System (INIS)

    Groves, C.R.

    1978-01-01

    In April 1978, a study of local movement of small mammals on the Subsurface Disposal Area (SDA) of the Radioactive Waste Management Complex (RWMC) was undertaken in conjunction with a study of rodent dispersal. Live trapping in May and June revealed a strong potential for the detection of local movement of at least four species of rodents. Information on this movement is important as each species, during burrowing, may transport radioactive waste from the point of interment to the surface. The area over which contamination may be spread, as fecal deposits or as metabolically incorporated elements, is a function of the daily movement of each animal. At least eight factors may effect size and shape of home range. These factors are discussed, techniques employed in the calculation of home range are outlined, and problems associated with live trapping and studying local movement of small mammals are considered

  4. Frugivores and seed dispersal: mechanisms and consequences for biodiversity of a key ecological interaction.

    Science.gov (United States)

    Jordano, Pedro; Forget, Pierre-Michel; Lambert, Joanna E; Böhning-Gaese, Katrin; Traveset, Anna; Wright, S Joseph

    2011-06-23

    The 5th Symposium on Frugivores and Seed Dispersal, held in Montpellier (France), 13-18 June 2010, brought together more than 220 researchers exemplifying a wide diversity of approaches to the study of frugivory and dispersal of seeds. Following Ted Fleming and Alejandro Estrada's initiative in 1985, this event was a celebration of the 25th anniversary of the first meeting in Veracruz, Mexico. Frugivory and seed dispersal are active research areas that have diversified in multiple directions since 1985 to include evolution (e.g. phylogenetic diversity and dispersal adaptations), physiology (e.g. sensory cues and digestion), landscape ecology (movement patterns), molecular ecology (e.g. gene flow, genetic diversity and structure), community ecology (e.g. mutualistic interaction networks) and conservation biology (effects of hunting, fragmentation, invasion and extinction), among others. This meeting provided an opportunity to assess conceptual and methodological progress, to present ever more sophisticated insights into frugivory in animals and dispersal patterns in plants, and to report the advances made in examining the mechanisms and consequences of seed dispersal for plants and frugivores.

  5. Immersion in Movement-Based Interaction

    Science.gov (United States)

    Pasch, Marco; Bianchi-Berthouze, Nadia; van Dijk, Betsy; Nijholt, Anton

    The phenomenon of immersing oneself into virtual environments has been established widely. Yet to date (to our best knowledge) the physical dimension has been neglected in studies investigating immersion in Human-Computer Interaction (HCI). In movement-based interaction the user controls the interface via body movements, e.g. direct manipulation of screen objects via gestures or using a handheld controller as a virtual tennis racket. It has been shown that physical activity affects arousal and that movement-based controllers can facilitate engagement in the context of video games. This paper aims at identifying movement features that influence immersion. We first give a brief survey on immersion and movement-based interfaces. Then, we report results from an interview study that investigates how users experience their body movements when interacting with movement-based interfaces. Based on the interviews, we identify four movement-specific features. We recommend them as candidates for further investigation.

  6. Communication Theory and the Consumer Movement-

    Science.gov (United States)

    Newsom, Doug

    1977-01-01

    Defines and traces the origins of the consumer movement and uses communication theories to explain the effects of the movement. Available from: Public Relations Review, Ray Hiebert, Dean, College of Journalism, University of Maryland, College Park, MD 20742. (MH)

  7. Functional jerks, tics, and paroxysmal movement disorders

    NARCIS (Netherlands)

    Dreissen, Y. E. M.; Cath, D C; Tijssen, M A J; Hallet, Mark; Stone, Jon; Carson, Alan

    2017-01-01

    Functional jerks are among the most common functional movement disorders. The diagnosis of functional jerks is mainly based on neurologic examination revealing specific positive clinical signs. Differentiation from other jerky movements, such as tics, organic myoclonus, and primary paroxysmal

  8. Mitigating trans-boundary movement of Bemisia tabaci (Hemiptera: Aleyrodidae) on Mentha sp. by pre-shipping treaments of biopesticides

    Science.gov (United States)

    Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a major pest of several important crops including vegetables, cereals, fruits, and ornamentals grown worldwide. One important mode of its dispersal is through the trans-boundary movement of infested plant materials. In order to prevent the sprea...

  9. Characterizing movement of ground-dwelling arthropods with a novel mark-capture method using fluorescent powder

    Science.gov (United States)

    Kayla I. Perry; Kimberly F. Wallin; John W. Wenzel; Daniel A. Herms

    2017-01-01

    A major knowledge gap exists in understanding dispersal potential of ground-dwelling arthropods, especially in forest ecosystems. Movement of the ground-dwelling arthropod community was quantified using a novel markcapture technique in which three different colored fluorescent powders in two separate mixtures were applied to the floor of a deciduous forest in...

  10. Movement patterns of three arboreal primates in a Neotropical moist forest explained by LiDAR-estimated canopy structure

    NARCIS (Netherlands)

    McLean, Kevin A.; Trainor, Anne M.; Asner, Gregory P.; Crofoot, Margaret C.; Hopkins, Mariah E.; Campbell, Christina J.; Martin, Roberta E.; Knapp, David E.; Jansen, Patrick A.

    2016-01-01

    Context: Many arboreal mammals in Neotropical forests are important seed dispersers that influence the spatial patterns of tree regeneration via their movement patterns, which in turn are determined by the canopy structure of the forest itself. However, the relationship between arboreal mammal

  11. Gravity effects on endogenous movements

    Science.gov (United States)

    Johnsson, Anders; Antonsen, Frank

    Gravity effects on endogenous movements A. Johnsson * and F. Antonsen *+ * Department of Physics, Norwegian University of Science and Technology,NO-7491, Trond-heim, Norway, E-mail: anders.johnsson@ntnu.no + Present address: Statoil Research Center Trondheim, NO-7005, Trondheim, Norway Circumnutations in stems/shoots exist in many plants and often consists of more or less regular helical movements around the plumb line under Earth conditions. Recent results on circumnu-tations of Arabidopsis in space (Johnsson et al. 2009) showed that minute amplitude oscilla-tions exist in weightlessness, but that centripetal acceleration (mimicking the gravity) amplified and/or created large amplitude oscillations. Fundamental mechanisms underlying these results will be discussed by modeling the plant tissue as a cylinder of cells coupled together. As a starting point we have modeled (Antonsen 1998) standing waves on a ring of biological cells, as first discussed in a classical paper (Turing 1952). If the coupled cells can change their water content, an `extension' wave could move around the ring. We have studied several, stacked rings of cells coupled into a cylinder that together represent a cylindrical plant tissue. Waves of extensions travelling around the cylinder could then represent the observable circumnutations. The coupling between cells can be due to cell-to-cell diffusion, or to transport via channels, and the coupling can be modeled to vary in both longitudinal and transversal direction of the cylinder. The results from ISS experiments indicate that this cylindrical model of coupled cells should be able to 1) show self-sustained oscillations without the impact of gravity (being en-dogenous) and 2) show how an environmental factor like gravity can amplify or generate the oscillatory movements. Gravity has been introduced in the model by a negative, time-delayed feed-back transport across the cylinder. This represents the physiological reactions to acceler

  12. A model for simulating the active dispersal of juvenile sea turtles with a case study on western Pacific leatherback turtles

    Science.gov (United States)

    Lalire, Maxime

    2017-01-01

    Oceanic currents are known to broadly shape the dispersal of juvenile sea turtles during their pelagic stage. Accordingly, simple passive drift models are widely used to investigate the distribution at sea of various juvenile sea turtle populations. However, evidence is growing that juveniles do not drift purely passively but also display some swimming activity likely directed towards favorable habitats. We therefore present here a novel Sea Turtle Active Movement Model (STAMM) in which juvenile sea turtles actively disperse under the combined effects of oceanic currents and habitat-driven movements. This model applies to all sea turtle species but is calibrated here for leatherback turtles (Dermochelys coriacea). It is first tested in a simulation of the active dispersal of juveniles originating from Jamursba-Medi, a main nesting beach of the western Pacific leatherback population. Dispersal into the North Pacific Ocean is specifically investigated. Simulation results demonstrate that, while oceanic currents broadly shape the dispersal area, modeled habitat-driven movements strongly structure the spatial and temporal distribution of juveniles within this area. In particular, these movements lead juveniles to gather in the North Pacific Transition Zone (NPTZ) and to undertake seasonal north-south migrations. More surprisingly, juveniles in the NPTZ are simulated to swim mostly towards west which considerably slows down their progression towards the American west coast. This increases their residence time, and hence the risk of interactions with fisheries, in the central and eastern part of the North Pacific basin. Simulated habitat-driven movements also strongly reduce the risk of cold-induced mortality. This risk appears to be larger among the juveniles that rapidly circulate into the Kuroshio than among those that first drift into the North Equatorial Counter Current (NECC). This mechanism might induce marked interannual variability in juvenile survival as the

  13. A model for simulating the active dispersal of juvenile sea turtles with a case study on western Pacific leatherback turtles.

    Science.gov (United States)

    Gaspar, Philippe; Lalire, Maxime

    2017-01-01

    Oceanic currents are known to broadly shape the dispersal of juvenile sea turtles during their pelagic stage. Accordingly, simple passive drift models are widely used to investigate the distribution at sea of various juvenile sea turtle populations. However, evidence is growing that juveniles do not drift purely passively but also display some swimming activity likely directed towards favorable habitats. We therefore present here a novel Sea Turtle Active Movement Model (STAMM) in which juvenile sea turtles actively disperse under the combined effects of oceanic currents and habitat-driven movements. This model applies to all sea turtle species but is calibrated here for leatherback turtles (Dermochelys coriacea). It is first tested in a simulation of the active dispersal of juveniles originating from Jamursba-Medi, a main nesting beach of the western Pacific leatherback population. Dispersal into the North Pacific Ocean is specifically investigated. Simulation results demonstrate that, while oceanic currents broadly shape the dispersal area, modeled habitat-driven movements strongly structure the spatial and temporal distribution of juveniles within this area. In particular, these movements lead juveniles to gather in the North Pacific Transition Zone (NPTZ) and to undertake seasonal north-south migrations. More surprisingly, juveniles in the NPTZ are simulated to swim mostly towards west which considerably slows down their progression towards the American west coast. This increases their residence time, and hence the risk of interactions with fisheries, in the central and eastern part of the North Pacific basin. Simulated habitat-driven movements also strongly reduce the risk of cold-induced mortality. This risk appears to be larger among the juveniles that rapidly circulate into the Kuroshio than among those that first drift into the North Equatorial Counter Current (NECC). This mechanism might induce marked interannual variability in juvenile survival as the

  14. A laboratory dispersant effectiveness test which reflects dispersant efficiency in the field

    International Nuclear Information System (INIS)

    Lunel, T.; Wood, P.

    1996-01-01

    Oil dispersion efficiencies of surfactants, from laboratory dispersion tests and field data were compared and calibrated. Data from an oil spill, where dispersants were used as a major part of the response, was analysed. The data was accumulated through the monitoring of the dispersant operation of the Sea Empress spill incident, in which Forties Blend oil was spilled at sea. This detailed data set was used to calibrate existing laboratory dispersant tests, and to devise a new International Dispersant Effectiveness Test. The objective was to create a comprehensive guide to decision making on whether and when to start a dispersant spraying operation. The dispersion efficiencies obtained from the laboratory dispersant tests were compared with field data. Flume tests produced the highest percentage of dispersed oil for all the dispersal tests. However, it was emphasised that the total percentage of oil dispersed should not be the only measure of dispersant effectiveness, since it does not distinguish between the contribution of natural and chemically enhanced dispersion. 9 refs., 1 tab., 9 figs

  15. Movement and Character. Lecture, London, 1946

    Science.gov (United States)

    Montesorri, Maria

    2013-01-01

    Dr. Montessori's words from the 1946 London Lectures describe principles of intelligence and character, the work of the hand, and movement with a purpose as being integral to self-construction. The perfection of movement is spiritual, says Dr. Montessori. Repetition of practical life exercises are exercises in movement with the dignity of human…

  16. 49 CFR 195.424 - Pipe movement.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Pipe movement. 195.424 Section 195.424... PIPELINE Operation and Maintenance § 195.424 Pipe movement. (a) No operator may move any line pipe, unless... in the line section involved are joined by welding unless— (1) Movement when the pipeline does not...

  17. 30 CFR 250.602 - Equipment movement.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Equipment movement. 250.602 Section 250.602... OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Well-Workover Operations § 250.602 Equipment movement. The movement of well-workover rigs and related equipment on and off a platform or from well to well on...

  18. 49 CFR 236.776 - Movement, trailing.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Movement, trailing. 236.776 Section 236.776 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Movement, trailing. The movement of a train over the points of a switch which face in the direction in...

  19. 30 CFR 250.502 - Equipment movement.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Equipment movement. 250.502 Section 250.502... OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Well-Completion Operations § 250.502 Equipment movement. The movement of well-completion rigs and related equipment on and off a platform or from well to well...

  20. 49 CFR 236.774 - Movement, facing.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Movement, facing. 236.774 Section 236.774 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Movement, facing. The movement of a train over the points of a switch which face in a direction opposite to...

  1. 9 CFR 92.3 - Movement restrictions.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Movement restrictions. 92.3 Section 92... ANIMAL PRODUCTS: PROCEDURES FOR REQUESTING RECOGNITION OF REGIONS § 92.3 Movement restrictions. Whenever... exist and the EC imposes prohibitions or other restrictions on the movement of animals or animal...

  2. Mixed movements/performance-based drawing

    DEFF Research Database (Denmark)

    Brabrand, Helle

    2011-01-01

    Mixed Movements is a research project engaged in performance-based architectural drawing. As one in a series working with architectonic implementation in relation to body and movements, the actual project relates body-movement and dynamic drawing and presents the material as interactive ‘space-time-tables’....

  3. Transformers: Movement Experiences for Early Childhood Classrooms

    Science.gov (United States)

    Vagovic, Julia

    2008-01-01

    Transformers are simple movement experiences for the classroom that engage the mind and body, focus energy, and help children transition to the next activity. Teachers can use them throughout the day, every day. The author explains the basic movements and suggests ways to build on them. They range from deep breathing to gentle wake-up movements to…

  4. Movement Education Framework (MEF) Made EZ!

    Science.gov (United States)

    Weiller-Abels, Karen; Bridges, Jennifer

    2011-01-01

    All physical educators want to provide lessons that foster success. Particularly essential to the movement education framework is not only providing lessons that foster motor success, but also to develop knowledge about movement to help the learner develop skill in executing all different types of movement. The framework and examples provided in…

  5. Salmon carcass movements in forest streams

    Science.gov (United States)

    Burke Strobel; Daniel R. Shivley; Brett B. Roper

    2009-01-01

    The movements of salmon carcasses over time were studied in two forest streams in the context of a large-scale salmon carcass supplementation program. The objectives were to assess both the level of treatment after stream flows had displaced carcasses and to evaluate whether the magnitude of carcass movements outside of a given reach could be predicted. The movements...

  6. Human movement data for malaria control and elimination strategic planning.

    Science.gov (United States)

    Pindolia, Deepa K; Garcia, Andres J; Wesolowski, Amy; Smith, David L; Buckee, Caroline O; Noor, Abdisalan M; Snow, Robert W; Tatem, Andrew J

    2012-06-18

    Recent increases in funding for malaria control have led to the reduction in transmission in many malaria endemic countries, prompting the national control programmes of 36 malaria endemic countries to set elimination targets. Accounting for human population movement (HPM) in planning for control, elimination and post-elimination surveillance is important, as evidenced by previous elimination attempts that were undermined by the reintroduction of malaria through HPM. Strategic control and elimination planning, therefore, requires quantitative information on HPM patterns and the translation of these into parasite dispersion. HPM patterns and the risk of malaria vary substantially across spatial and temporal scales, demographic and socioeconomic sub-groups, and motivation for travel, so multiple data sets are likely required for quantification of movement. While existing studies based on mobile phone call record data combined with malaria transmission maps have begun to address within-country HPM patterns, other aspects remain poorly quantified despite their importance in accurately gauging malaria movement patterns and building control and detection strategies, such as cross-border HPM, demographic and socioeconomic stratification of HPM patterns, forms of transport, personal malaria protection and other factors that modify malaria risk. A wealth of data exist to aid filling these gaps, which, when combined with spatial data on transport infrastructure, traffic and malaria transmission, can answer relevant questions to guide strategic planning. This review aims to (i) discuss relevant types of HPM across spatial and temporal scales, (ii) document where datasets exist to quantify HPM, (iii) highlight where data gaps remain and (iv) briefly put forward methods for integrating these datasets in a Geographic Information System (GIS) framework for analysing and modelling human population and Plasmodium falciparum malaria infection movements.

  7. Human movement data for malaria control and elimination strategic planning

    Directory of Open Access Journals (Sweden)

    Pindolia Deepa K

    2012-06-01

    Full Text Available Abstract Recent increases in funding for malaria control have led to the reduction in transmission in many malaria endemic countries, prompting the national control programmes of 36 malaria endemic countries to set elimination targets. Accounting for human population movement (HPM in planning for control, elimination and post-elimination surveillance is important, as evidenced by previous elimination attempts that were undermined by the reintroduction of malaria through HPM. Strategic control and elimination planning, therefore, requires quantitative information on HPM patterns and the translation of these into parasite dispersion. HPM patterns and the risk of malaria vary substantially across spatial and temporal scales, demographic and socioeconomic sub-groups, and motivation for travel, so multiple data sets are likely required for quantification of movement. While existing studies based on mobile phone call record data combined with malaria transmission maps have begun to address within-country HPM patterns, other aspects remain poorly quantified despite their importance in accurately gauging malaria movement patterns and building control and detection strategies, such as cross-border HPM, demographic and socioeconomic stratification of HPM patterns, forms of transport, personal malaria protection and other factors that modify malaria risk. A wealth of data exist to aid filling these gaps, which, when combined with spatial data on transport infrastructure, traffic and malaria transmission, can answer relevant questions to guide strategic planning. This review aims to (i discuss relevant types of HPM across spatial and temporal scales, (ii document where datasets exist to quantify HPM, (iii highlight where data gaps remain and (iv briefly put forward methods for integrating these datasets in a Geographic Information System (GIS framework for analysing and modelling human population and Plasmodium falciparum malaria infection movements.

  8. Pollen Forecast and Dispersion Modelling

    Science.gov (United States)

    Costantini, Monica; Di Giuseppe, Fabio; Medaglia, Carlo Maria; Travaglini, Alessandro; Tocci, Raffaella; Brighetti, M. Antonia; Petitta, Marcello

    2014-05-01

    The aim of this study is monitoring, mapping and forecast of pollen distribution for the city of Rome using in-situ measurements of 10 species of common allergenic pollens and measurements of PM10. The production of daily concentration maps, associated to a mobile phone app, are innovative compared to existing dedicated services to people who suffer from respiratory allergies. The dispersal pollen is one of the most well-known causes of allergic disease that is manifested by disorders of the respiratory functions. Allergies are the third leading cause of chronic disease and it is estimated that tens millions of people in Italy suffer from it. Recent works reveal that during the last few years there was a progressive increase of affected subjects, especially in urban areas. This situation may depend: on the ability to transport of pollutants, on the ability to react between pollutants and pollen and from a combination of other irritants, existing in densely populated and polluted urban areas. The methodology used to produce maps is based on in-situ measurements time series relative to 2012, obtained from networks of air quality and pollen stations in the metropolitan area of Rome. The monitoring station aerobiological of University of Rome "Tor Vergata" is located at the Department of Biology. The instrument used to pollen monitoring is a volumetric sampler type Hirst (Hirst 1952), Model 2000 VPPS Lanzoni; the data acquisition is carried out as reported in Standard UNI 11008:2004 - "Qualità dell'aria - Metodo di campionamento e conteggio dei granuli pollinici e delle spore fungine aerodisperse" - the protocol that describes the procedure for measuring of the concentration of pollen grains and fungal spores dispersed into the atmosphere, and reported in the "Manuale di gestione e qualità della R.I.M.A" (Travaglini et. al. 2009). All 10 allergenic pollen are monitored since 1996. At Tor Vergata university is also operating a meteorological station (SP2000, CAE

  9. Tomography with energy dispersive diffraction

    Science.gov (United States)

    Stock, S. R.; Okasinski, J. S.; Woods, R.; Baldwin, J.; Madden, T.; Quaranta, O.; Rumaiz, A.; Kuczewski, T.; Mead, J.; Krings, T.; Siddons, P.; Miceli, A.; Almer, J. D.

    2017-09-01

    X-ray diffraction can be used as the signal for tomographic reconstruction and provides a cross-sectional map of the crystallographic phases and related quantities. Diffraction tomography has been developed over the last decade using monochromatic x-radiation and an area detector. This paper reports tomographic reconstruction with polychromatic radiation and an energy sensitive detector array. The energy dispersive diffraction (EDD) geometry, the instrumentation and the reconstruction process are described and related to the expected resolution. Results of EDD tomography are presented for two samples containing hydroxyapatite (hAp). The first is a 3D-printed sample with an elliptical crosssection and contains synthetic hAp. The second is a human second metacarpal bone from the Roman-era cemetery at Ancaster, UK and contains bio-hAp which may have been altered by diagenesis. Reconstructions with different diffraction peaks are compared. Prospects for future EDD tomography are also discussed.

  10. Determination of dispersity of crushed granite

    International Nuclear Information System (INIS)

    Liu Dejun; Fan Xianhua; Zhang Yingjie; Yao Jun; Zhou Duo; Wang Yong

    2004-01-01

    The experimental crushed granite column breakthrough curves, using 99 Tc as spike tracer and 3 H as invariant tracer, are analyzed by different linear regression techniques. Dispersity of crushed granite and retardation factor of 99 TcO 4 - on the crushed granite are determined simultaneously by one linear regression technique. Dispersity of crushed granite is also obtained with 3 H as invariant tracer by the other linear regression technique. The dispersities found by spike source and invariant source methods are compared. The experimental results show that the dispersity found by spike source method is close to that found by invariant source method. It indicates that dispersity is only the characteristic of dispersion medium

  11. Determination of dispersity of crushed granite

    International Nuclear Information System (INIS)

    Liu, D.J.; Fan, X.H.

    2005-01-01

    Experimental crushed granite column breakthrough curves, using 99 Tc as spike tracer and 3 H as invariant tracer, were analyzed by different linear regression techniques. Dispersity of crushed granite and the retardation factor of 99 TcO 4 - on the crushed granite were determined simultaneously by one linear regression. Dispersity of crushed granite was also obtained with 3 H as invariant tracer by the other linear regression. The dispersities found by spike source and invariant source methods are compared. Experimental results show that the dispersity found by the spike source method is close to that found by the invariant source method. This indicates that dispersity is only a characteristic of the dispersion medium. (author)

  12. Single-particle dispersion in compressible turbulence

    Science.gov (United States)

    Zhang, Qingqing; Xiao, Zuoli

    2018-04-01

    Single-particle dispersion statistics in compressible box turbulence are studied using direct numerical simulation. Focus is placed on the detailed discussion of effects of the particle Stokes number and turbulent Mach number, as well as the forcing type. When solenoidal forcing is adopted, it is found that the single-particle dispersion undergoes a transition from the ballistic regime at short times to the diffusive regime at long times, in agreement with Taylor's particle dispersion argument. The strongest dispersion of heavy particles is announced when the Stokes number is of order 1, which is similar to the scenario in incompressible turbulence. The dispersion tends to be suppressed as the Mach number increases. When hybrid solenoidal and compressive forcing at a ratio of 1/2 is employed, the flow field shows apparent anisotropic property, characterized by the appearance of large shock wave structures. Accordingly, the single-particle dispersion shows extremely different behavior from the solenoidal forcing case.

  13. Crossing the front: contrasting storm-forced dispersal dynamics revealed by biological, geological and genetic analysis of beach-cast kelp.

    Science.gov (United States)

    Waters, Jonathan M; King, Tania M; Fraser, Ceridwen I; Craw, Dave

    2018-03-01

    The subtropical front (STF) generally represents a substantial oceanographic barrier to dispersal between cold-sub-Antarctic and warm-temperate water masses. Recent studies have suggested that storm events can drastically influence marine dispersal and patterns. Here we analyse biological and geological dispersal driven by two major, contrasting storm events in southern New Zealand, 2017. We integrate biological and physical data to show that a severe southerly system in July 2017 disrupted this barrier by promoting movement of substantial numbers of southern sub-Antarctic Durvillaea kelp rafts across the STF, to make landfall in mainland NZ. By contrast, a less intense easterly storm (Cyclone Cook, April 2017) resulted in more moderate dispersal distances, with minimal dispersal between the sub-Antarctic and mainland New Zealand. These quantitative analyses of approximately 200 freshly beach-cast kelp specimens indicate that storm intensity and wind direction can strongly influence marine dispersal and landfall outcomes. © 2018 The Author(s).

  14. Membranes as separators of dispersed emulsion phases

    OpenAIRE

    Lefferts, A.G.

    1997-01-01

    The reuse or discharge of industrial waste waters, containing small fractions of dispersed oil, requires a purification treatment for which membranes can be used. If only little oil is present, removal of the dispersed phase might be preferable to the more commonly applied removal of the continuous phase. For this purpose dispersed phase separators can be applied, which combine the features of conventional coalescers and membrane filtration. The membrane surface promotes coalescence ...

  15. Formulation of disperse systems science and technology

    CERN Document Server

    Tadros, Tharwat F

    2014-01-01

    This book presents comprehensively the science and technology behind the formulation of disperse systems like emulsions, suspensions, foams and others. Starting with a general introduction, the book covers a broad range of topics like the role of different classes of surfactants, stability of disperse systems, formulation of different dispersions, evaluation of formulations and many more. Many examples are included, too. Written by the experienced author and editor Tharwart Tadros, this book is indispensable for every scientist working in the field.

  16. Key factors for UV curable pigment dispersions

    International Nuclear Information System (INIS)

    Magny, B.; Pezron, E.; Ciceron, P.H.; Askienazy, A.

    1999-01-01

    UV oligomers with good pigment dispersion are needed to allow good formulation flexibility and possibility to apply thinner films. Pigment dispersion mainly depends on three phenomena: the wetting of agglomerates, the breakage of agglomerates by mechanical stress and the stabilization of smaller agglomerates and primary particles against flocculation. It has been shown that oligomers with low viscosity and low surface tension induce a good pigment wetting. Examples of monomers and oligomers for good pigment dispersion are given

  17. Crocodylus acutus (American Crocodile). Long distance juvenile movement

    Science.gov (United States)

    Crespo, Rafael; Beauchamp, Jeffrey S.; Mazzotti, Frank; Cherkiss, Michael S.

    2015-01-01

    the distance traveled ranged from 0.3 km to 90.2 km. The data showed that the smaller alligators moved greater distance than larger ones (Lance et al. 2011. Southeast Nat. 10:389–398). An ongoing 30 year mark and recapture study for Crocodylus acutus in Florida allowed us to look at long distance movement (>30 km) of juveniles (30km). Initial and most recent captures as a juvenile were used to analyze distances moved (Fig. 1). These distances were measured linearly between capture locations. Maximum linear distances of 76.3 km and 69.6 km were recorded for animals 4838 and 6662. All crocodiles moved from nesting habitat through potentially optimal nursery habitat prior to reaching their recapture locations. These juvenile long distance movements could be due to larger crocodiles facilitating their dispersal from the nest location (Lance et al. 2011. op. cit.). These data (Table 1.) support that there is exchange of individuals among the nesting colonies and our ongoing efforts to monitor this threatened species allow us to make observations of how juvenile crocodiles are moving throughout the landscape in an ecosystem currently undergoing restoration.

  18. What makes a movement a gesture?

    Science.gov (United States)

    Novack, Miriam A; Wakefield, Elizabeth M; Goldin-Meadow, Susan

    2016-01-01

    Theories of how adults interpret the actions of others have focused on the goals and intentions of actors engaged in object-directed actions. Recent research has challenged this assumption, and shown that movements are often interpreted as being for their own sake (Schachner & Carey, 2013). Here we postulate a third interpretation of movement-movement that represents action, but does not literally act on objects in the world. These movements are gestures. In this paper, we describe a framework for predicting when movements are likely to be seen as representations. In Study 1, adults described one of three scenes: (1) an actor moving objects, (2) an actor moving her hands in the presence of objects (but not touching them) or (3) an actor moving her hands in the absence of objects. Participants systematically described the movements as depicting an object-directed action when the actor moved objects, and favored describing the movements as depicting movement for its own sake when the actor produced the same movements in the absence of objects. However, participants favored describing the movements as representations when the actor produced the movements near, but not on, the objects. Study 2 explored two additional features-the form of an actor's hands and the presence of speech-like sounds-to test the effect of context on observers' classification of movement as representational. When movements are seen as representations, they have the power to influence communication, learning, and cognition in ways that movement for its own sake does not. By incorporating representational gesture into our framework for movement analysis, we take an important step towards developing a more cohesive understanding of action-interpretation. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Liquid agents for dispersion of hard alloys

    International Nuclear Information System (INIS)

    Putintseva, M.N.

    2006-01-01

    Effects of dispersant properties on granulometric, chemical, and phase composition of the products of WC hard alloy electroerosion are considered. It is established that an increase of liquid dispersant permittivity results in enhanced powder dispersity, and an increase of boiling temperature and kinematic viscosity of a hydrocarbon liquid promotes a carbon loss from WC and intensifies pyrolysis of the liquid.On electroerosion of WC base hard alloy in oil a powder particle consists of b-WC+W 2 C phases, in kerosine - of a-WC+b-WC, in distilled water - of W+W 2 C. The viscosity of liquid dispersants practically has no effect on powder particle size [ru

  20. Dispersal of Engineered Male Aedes aegypti Mosquitoes.

    Science.gov (United States)

    Winskill, Peter; Carvalho, Danilo O; Capurro, Margareth L; Alphey, Luke; Donnelly, Christl A; McKemey, Andrew R

    2015-11-01

    Aedes aegypti, the principal vector of dengue fever, have been genetically engineered for use in a sterile insect control programme. To improve our understanding of the dispersal ecology of mosquitoes and to inform appropriate release strategies of 'genetically sterile' male Aedes aegypti detailed knowledge of the dispersal ability of the released insects is needed. The dispersal ability of released 'genetically sterile' male Aedes aegypti at a field site in Brazil has been estimated. Dispersal kernels embedded within a generalized linear model framework were used to analyse data collected from three large scale mark release recapture studies. The methodology has been applied to previously published dispersal data to compare the dispersal ability of 'genetically sterile' male Aedes aegypti in contrasting environments. We parameterised dispersal kernels and estimated the mean distance travelled for insects in Brazil: 52.8 m (95% CI: 49.9 m, 56.8 m) and Malaysia: 58.0 m (95% CI: 51.1 m, 71.0 m). Our results provide specific, detailed estimates of the dispersal characteristics of released 'genetically sterile' male Aedes aegypti in the field. The comparative analysis indicates that despite differing environments and recapture rates, key features of the insects' dispersal kernels are conserved across the two studies. The results can be used to inform both risk assessments and release programmes using 'genetically sterile' male Aedes aegypti.

  1. Effectiveness of dispersants on thick oil slicks

    International Nuclear Information System (INIS)

    Ross, S.; Belore, R.

    1993-01-01

    Experiments were conducted to determine the relationship between dispersant effectiveness and oil slick thickness, and thereby determine the optimum time for applying dispersant onto spilled oil at sea. Tests were completed at a lab-scale level by varying the three parameters of oil type, dispersant application, and oil thickness. The tests were intended to be comparative only. The primary oils used were Alberta sweet mix blend and Hibernia B-27 crude. The dispersant, Corexit 9527, was applied either premixed with the oil, dropwise in one application, or dropwise in multiple applications to simulate a multi-hit aircraft operation. The apparatus used in the experiment was an oscillating hoop tank, with oil-containing rings used to obtain and maintain uniform slick thickness. The results indicate that the effectiveness potential of a chemical dispersant does not decrease as slick thickness increases. In fact, results of the tests involving Hibernia oil suggest that oils that tend to herd easily would be treated more effectively if dispersant were applied when the oil was relatively thick (1 mm or greater) to avoid herding problems. The oil slicks premixed with dispersant did not disperse well in the thick oil tests, not because of dispersant-oil interaction problems but because of reduced mixing energy. 6 refs., 4 figs., 1 tab

  2. Modelling airborne dispersion of coarse particulate material

    International Nuclear Information System (INIS)

    Apsley, D.D.

    1989-03-01

    Methods of modelling the airborne dispersion and deposition of coarse particulates are presented, with the emphasis on the heavy particles identified as possible constituents of releases from damaged AGR fuel. The first part of this report establishes the physical characteristics of the irradiated particulate in airborne emissions from AGR stations. The second part is less specific and describes procedures for extending current dispersion/deposition models to incorporate a coarse particulate component: the adjustment to plume spread parameters, dispersion from elevated sources and dispersion in conjunction with building effects and plume rise. (author)

  3. Examining Age-Related Movement Representations for Sequential (Fine-Motor) Finger Movements

    Science.gov (United States)

    Gabbard, Carl; Cacola, Priscila; Bobbio, Tatiana

    2011-01-01

    Theory suggests that imagined and executed movement planning relies on internal models for action. Using a chronometry paradigm to compare the movement duration of imagined and executed movements, we tested children aged 7-11 years and adults on their ability to perform sequential finger movements. Underscoring this tactic was our desire to gain a…

  4. Mapping behavioral landscapes for animal movement: a finite mixture modeling approach

    Science.gov (United States)

    Tracey, Jeff A.; Zhu, Jun; Boydston, Erin E.; Lyren, Lisa M.; Fisher, Robert N.; Crooks, Kevin R.

    2013-01-01

    Because of its role in many ecological processes, movement of animals in response to landscape features is an important subject in ecology and conservation biology. In this paper, we develop models of animal movement in relation to objects or fields in a landscape. We take a finite mixture modeling approach in which the component densities are conceptually related to different choices for movement in response to a landscape feature, and the mixing proportions are related to the probability of selecting each response as a function of one or more covariates. We combine particle swarm optimization and an Expectation-Maximization (EM) algorithm to obtain maximum likelihood estimates of the model parameters. We use this approach to analyze data for movement of three bobcats in relation to urban areas in southern California, USA. A behavioral interpretation of the models revealed similarities and differences in bobcat movement response to urbanization. All three bobcats avoided urbanization by moving either parallel to urban boundaries or toward less urban areas as the proportion of urban land cover in the surrounding area increased. However, one bobcat, a male with a dispersal-like large-scale movement pattern, avoided urbanization at lower densities and responded strictly by moving parallel to the urban edge. The other two bobcats, which were both residents and occupied similar geographic areas, avoided urban areas using a combination of movements parallel to the urban edge and movement toward areas of less urbanization. However, the resident female appeared to exhibit greater repulsion at lower levels of urbanization than the resident male, consistent with empirical observations of bobcats in southern California. Using the parameterized finite mixture models, we mapped behavioral states to geographic space, creating a representation of a behavioral landscape. This approach can provide guidance for conservation planning based on analysis of animal movement data using

  5. Stereotypic movement disorder: easily missed.

    Science.gov (United States)

    Freeman, Roger D; Soltanifar, Atefeh; Baer, Susan

    2010-08-01

    To expand the understanding of stereotypic movement disorder (SMD) and its differentiation from tics and autistic stereotypies. Forty-two children (31 males, mean age 6y 3mo, SD 2y 8mo; 11 females, mean age 6y 7mo, SD 1y 9mo) consecutively diagnosed with SMD, without-self-injurious behavior, intellectual disability, sensory impairment, or an autistic spectrum disorder (ASD), were assessed in a neuropsychiatry clinic. A list of probe questions on the nature of the stereotypy was administered to parents (and to children if developmentally ready). Questionnaires administered included the Stereotypy Severity Scale, Short Sensory Profile, Strengths and Difficulties Questionnaire, Repetitive Behavior Scale--Revised, and the Developmental Coordination Disorder Questionnaire. The stereotyped movement patterns were directly observed and in some cases further documented by video recordings made by parents. The probe questions were used again on follow-up at a mean age of 10 years 7 months (SD 4y 4mo). Mean age at onset was 17 months. Males exceeded females by 3:1. Family history of a pattern of SMD was reported in 13 and neuropsychiatric comorbidity in 30 (attention-deficit-hyperactivity disorder in 16, tics in 18, and developmental coordination disorder in 16). Obsessive-compulsive disorder occurred in only two. The Short Sensory Profile correlated with comorbidity (p<0.001), the Stereotypy Severity Scale (p=0.009), and the Repetitive Behavior Scale (p<0.001); the last correlated with the Stereotypy Severity Scale (p=0.001). Children (but not their parents) liked their movements, which were usually associated with excitement or imaginative play. Mean length of follow-up was 4 years 8 months (SD 2y 10mo). Of the 39 children followed for longer than 6 months, the behavior stopped or was gradually shaped so as to occur primarily privately in 25. Misdiagnosis was common: 26 were initially referred as tics, 10 as ASD, five as compulsions, and one as epilepsy. Co-occurring facial

  6. Brownian movement and molecular reality

    CERN Document Server

    Perrin, Jean

    2005-01-01

    How do we know that molecules really exist? An important clue came from Brownian movement, a concept developed in 1827 by botanist Robert Brown, who noticed that tiny objects like pollen grains shook and moved erratically when viewed under a microscope. Nearly 80 years later, in 1905, Albert Einstein explained this ""Brownian motion"" as the result of bombardment by molecules. Einstein offered a quantitative explanation by mathematically estimating the average distance covered by the particles over time as a result of molecular bombardment. Four years later, Jean Baptiste Perrin wrote Brownia

  7. Case vignettes of movement disorders.

    Science.gov (United States)

    Yung, C Y

    1983-08-01

    This paper reports five movement disorders cases to serve as a basis for discussion of the problems encountered in the clinical management of these cases, and the pathophysiological mechanisms involved in these disorders as presented. Case 1 is a description of the subjective experience of a patient with acute orofacial dystonia from promethazine. Case 2 is the use of clonazepam is post-head injury tics. Case 3 is the complication from discontinuation of haloperidol and benztropine mesylate treatment. Case 4 is myoclonus in subacute sclerosing Panencephalitis, and Case 5 is rebound tremor from withdrawal of a beta-adrenergic blocker.

  8. Movement of the diaphragm during radiation treatment

    International Nuclear Information System (INIS)

    Nishioka, Masayuki; Fujioka, Tomio; Sakurai, Makoto; Nakajima, Toshifumi; Onoyama, Yasuto.

    1991-01-01

    Movement of the target volume during the exposure to radiation results in decreased accuracy in radiotherapy. We carried out the quantitative evaluation of the movement of the diaphragm during the radiation therapy. Seventy seven patients, who received radiation therapy for lung cancer from December 1988 to February 1990 at the Osaka-prefectural Habikino Hospital, were studied. The movement was recorded with a sonoprinter at the time of treatment planning for radiotherapy, and the length of movement was evaluated at 6 points on the diaphragm. In a study of 402 points in 77 patients, the average movement was 12 mm, and the maximum movement was 40 mm. At the 17% of the points, the movement exceeded 20 mm. The largest movement was observed at the outer point of the right lung. Movement was greater in men than in women. Performance status was not related to the degree of movement. We concluded that in chest and abdominal irradiation, movement caused by respiration is not negligible, and synchronized radiotherapy should be developed in the future. (author)

  9. Dispersion properties of transverse waves in electrically polarized BECs

    International Nuclear Information System (INIS)

    Andreev, Pavel A; Kuz'menkov, L S

    2014-01-01

    Further development of the method of quantum hydrodynamics in applications for Bose–Einstein condensates (BECs) is presented. To consider the evolution of polarization direction along with particle movement, we have developed a corresponding set of quantum hydrodynamic equations. It includes equations of the polarization evolution and the polarization-current evolution along with the continuity equation and the Euler equation (the momentum-balance equation). Dispersion properties of the transverse waves, including the electromagnetic waves propagating through the BECs, are considered. To this end, we consider a full set of the Maxwell equations for the description of electromagnetic field dynamics. This approximation gives us the possibility of considering the electromagnetic waves along with the matter waves. We find a splitting of the electromagnetic-wave dispersion on two branches. As a result, we have four solutions, two for the electromagnetic waves and two for the matter waves; the last two are the concentration-polarization waves appearing as a generalization of the Bogoliubov mode. We also find that if the matter wave propagates perpendicular to the external electric field then the dipolar contribution does not disappear (as it follows from our generalization of the Bogoliubov spectrum). A small dipolar frequency shift exists in this case due to the transverse electric field of perturbation. (paper)

  10. Administering and Detecting Protein Marks on Arthropods for Dispersal Research.

    Science.gov (United States)

    Hagler, James R; Machtley, Scott A

    2016-01-28

    Monitoring arthropod movement is often required to better understand associated population dynamics, dispersal patterns, host plant preferences, and other ecological interactions. Arthropods are usually tracked in nature by tagging them with a unique mark and then re-collecting them over time and space to determine their dispersal capabilities. In addition to actual physical tags, such as colored dust or paint, various types of proteins have proven very effective for marking arthropods for ecological research. Proteins can be administered internally and/or externally. The proteins can then be detected on recaptured arthropods with a protein-specific enzyme-linked immunosorbent assay (ELISA). Here we describe protocols for externally and internally tagging arthropods with protein. Two simple experimental examples are demonstrated: (1) an internal protein mark introduced to an insect by providing a protein-enriched diet and (2) an external protein mark topically applied to an insect using a medical nebulizer. We then relate a step-by-step guide of the sandwich and indirect ELISA methods used to detect protein marks on the insects. In this demonstration, various aspects of the acquisition and detection of protein markers on arthropods for mark-release-recapture, mark-capture, and self-mark-capture types of research are discussed, along with the various ways that the immunomarking procedure has been adapted to suit a wide variety of research objectives.

  11. Generalized Pareto for Pattern-Oriented Random Walk Modelling of Organisms' Movements.

    Directory of Open Access Journals (Sweden)

    Sophie Bertrand

    Full Text Available How organisms move and disperse is crucial to understand how population dynamics relates to the spatial heterogeneity of the environment. Random walk (RW models are typical tools to describe movement patterns. Whether Lévy or alternative RW better describes forager movements is keenly debated. We get around this issue using the Generalized Pareto Distribution (GPD. GPD includes as specific cases Normal, exponential and power law distributions, which underlie Brownian, Poisson-like and Lévy walks respectively. Whereas previous studies typically confronted a limited set of candidate models, GPD lets the most likely RW model emerge from the data. We illustrate the wide applicability of the method using GPS-tracked seabird foraging movements and fishing vessel movements tracked by Vessel Monitoring System (VMS, both collected in the Peruvian pelagic ecosystem. The two parameters from the fitted GPD, a scale and a shape parameter, provide a synoptic characterization of the observed movement in terms of characteristic scale and diffusive property. They reveal and quantify the variability, among species and individuals, of the spatial strategies selected by predators foraging on a common prey field. The GPD parameters constitute relevant metrics for (1 providing a synthetic and pattern-oriented description of movement, (2 using top predators as ecosystem indicators and (3 studying the variability of spatial behaviour among species or among individuals with different personalities.

  12. Invasive Brown Treesnake movements at road edges indicate road-crossing avoidance

    Science.gov (United States)

    Siers, Shane R.; Savidge, Julie S; Reed, Robert N.

    2014-01-01

    Roads have significant impacts on the dispersal of wildlife. Although this poses a threat to the abundance and diversity of desirable flora and fauna, it also affords some opportunity for enhancing control of invasive species. Roads are the most common terrain features that may affect the rate of landscape-scale movements of invasive Brown Treesnakes (Boiga irregularis) throughout Guam. We radio tracked 45 free-ranging Brown Treesnakes in close proximity to two roads in Guam and recorded instances where daily relocations of snakes spanned roads. Then we reconstructed observed movement histories with randomized turning angles, which served as a useful null hypothesis for assessing the effect of roads or road edge habitat on Brown Treesnake movement patterns. Random walk simulations demonstrated that Brown Treesnakes crossed these roads at a rate far lower than would be expected if snake movement was random with respect to roads and road edge habitat. We discuss two alternative hypotheses for these results: 1) habitat gaps posed by roads physically or behaviorally restrict snake movement; or 2) road edges provide preferred foraging habitat from which snakes are reluctant to depart. Because roads often form the boundaries of jurisdictional and management units, the effects of roads on the movement of invasive Brown Treesnakes will influence the prospects for success of future landscape-level suppression efforts.

  13. Generalized Pareto for Pattern-Oriented Random Walk Modelling of Organisms' Movements.

    Science.gov (United States)

    Bertrand, Sophie; Joo, Rocío; Fablet, Ronan

    2015-01-01

    How organisms move and disperse is crucial to understand how population dynamics relates to the spatial heterogeneity of the environment. Random walk (RW) models are typical tools to describe movement patterns. Whether Lévy or alternative RW better describes forager movements is keenly debated. We get around this issue using the Generalized Pareto Distribution (GPD). GPD includes as specific cases Normal, exponential and power law distributions, which underlie Brownian, Poisson-like and Lévy walks respectively. Whereas previous studies typically confronted a limited set of candidate models, GPD lets the most likely RW model emerge from the data. We illustrate the wide applicability of the method using GPS-tracked seabird foraging movements and fishing vessel movements tracked by Vessel Monitoring System (VMS), both collected in the Peruvian pelagic ecosystem. The two parameters from the fitted GPD, a scale and a shape parameter, provide a synoptic characterization of the observed movement in terms of characteristic scale and diffusive property. They reveal and quantify the variability, among species and individuals, of the spatial strategies selected by predators foraging on a common prey field. The GPD parameters constitute relevant metrics for (1) providing a synthetic and pattern-oriented description of movement, (2) using top predators as ecosystem indicators and (3) studying the variability of spatial behaviour among species or among individuals with different personalities.

  14. Determination of dispersion coefficients in the River Plate

    International Nuclear Information System (INIS)

    Maggio, G.E.; Graino, J.G.; Kopp, U.I.; Tripoli, C.R.

    1987-01-01

    The determination of dispersion coefficients of contaminants through a radioactive tracer was performed as a contribution to the development of a mathematical model for a zone of the River Plate, close to the effluent discharge. During March 1987, six operations of tracer (I-131) injection and follow-up were carried out. The injection was performed by breaking a bulb under water and the follow-up of the 'radioactive spot' was done by means of a boat. Once the 'radioactive spot' was located (approximately 2 hours after the injection) a series of transversal movements over it was effected, measuring the activity concentration by means of a submerged detector. At the same time the coordinates of each point were determined in order to draw a map of the activity distribution. This procedure was repeated for different spot positions. This set of data can be plotted on a map of the zone under study, so as to obtain a set of iso activity curves. However, these curves would be representative provided that corrections are made for the boat speed, the water speed and the half-life of radionuclide. From each set of iso activity curves, the variance and the increase of variance, as well as the dispersion coefficients, can be determined. This procedure was applied to each one of the six above mentioned operations. Presently, different values of dispersion coefficient are available for different river conditions. These values, together with other parameters, such as wind velocity, temperature, salinity, bacterial behaviour, etc., will allow the calibration of the mathematical model. (Author)

  15. Cleaner Production: A Growing Movement in Brazilian Companies

    Directory of Open Access Journals (Sweden)

    Oduvaldo Vendrametto

    2010-03-01

    Full Text Available Cleaner Production (CP is gaining emphasis in both world and Brazilian production sectors. Nature’s warnings indicating the exhaustion of any capacity to absorb and regenerate waste, stricter legislation regarding pollution emitters, market competitiveness associated with environmental and social responsibility cause concerns and lead to actions to reduce aggressions against the environment. This paper shows evidence of this concern and presents cases in which a large automotive industry, acting as a partner to suppliers, promotes changes in how it delivers its products, eliminating large cardboard, plastic and wood packaging. A small company had a similar initiative, reducing the use of cardboard and plastic packaging. More important is the revelation of a widely dispersed, yet growing and incremental movement of responsibilities among companies.The benefits of cleaner production implementation were evaluated by confronting environmental and financial assessment. For the ambient evaluation, it will be used methodology of Material Intensity (Wuppertal Institute, a.

  16. Do culverts impact the movements of the endangered white-clawed crayfish?

    Directory of Open Access Journals (Sweden)

    Louca V.

    2014-01-01

    Full Text Available Culverts can impact the migration and dispersal of aquatic animals and result in population fragmentation, increasing the risk of local extinction for endangered species such as the white-clawed crayfish Austropotamobius pallipes. This study used radio telemetry and passive integrated transponder (PIT telemetry to determine whether existing and experimental covered culverts affect the upstream and downstream movements of adult white-clawed crayfish. Daily crayfish movement rates did not differ significantly between an unlit 363-m long culvert and open stream channel sections. Crayfish moved into dark, covered sections volitionally. However, limited upstream movement occurred at sudden transitions of bed height or smooth-concrete box culvert sections with fast flow, suggesting partial barrier effects. In the 20-m long experimental in-stream culvert, also dark, but with natural stream bed, 70% of radio-tagged crayfish released downstream entered the culvert, as did 60% of those released upstream. Overall 35% passed through, with similar numbers in each direction. We conclude that dark culverts up to several hundred metres do not inhibit dispersal of white-clawed crayfish, provided stream slope, bed type and water velocity are amenable for movement and refuge. Care is required to ensure that culverts are bioengineered to ensure that average water velocity is sufficiently low and local hydraulic variation high, the bed and/or sidewalls contain refuge structures, and there are no cross-channel steps in bed level. Smooth-bedded box culverts are unlikely to be suitable for white-clawed crayfish.

  17. Dispersion of Dielectric Permittivity in a Nanocrystalline Cellulose-Triglycine Sulfate Composite at Low and Ultralow Frequencies

    Science.gov (United States)

    Thu'o'ng, Nguyen Hoai; Sidorkin, A. S.; Milovidova, S. D.

    2018-03-01

    The dispersion of dielectric permittivity in nanocrystalline cellulose-triglycine sulfate composites is studied in the range of frequencies from 10-3 to 106 Hz, at temperatures varying from room temperature to the temperature of phase transition in this composite (54°C), in weak electric fields (1 V cm-1). Two behaviors for the dielectric dispersion are identified in the studied frequency range: at ultralow frequencies (10-3-10 Hz), the dispersion is due to Maxwell-Wagner polarization, while at higher frequencies (10-106 Hz), the dispersion is due to the movement of domain walls in the embedded triglycine sulfate crystallites. An additional peak in the temperature-dependent profiles of dielectric permittivity is detected at lower temperatures in freshly prepared samples of the considered composite; we associate it with the presence of residual water in these samples.

  18. Does an ant-dispersed plant, Viola reichenbachiana, suffer from reduced seed dispersal under inundation disturbances?

    NARCIS (Netherlands)

    Prinzing, A.; Dauber, J.; Hammer, E.; Hammouti, N.; Bohning-Gaese, K.

    2008-01-01

    Many plant species use ants as seed dispersers. This dispersal mode is considered to be susceptible to disturbances, but the effect of natural, small-scale disturbances is still unknown. We investigated how small-scale disturbances due to inundation affect seed dispersal in Viola reichenbachiana, a

  19. Dispersed and decentralised settlement system

    Directory of Open Access Journals (Sweden)

    Andrej Černe

    2004-01-01

    Full Text Available In the process of reintegration of the urban system new settlements are emerging on theurban rim, transitional zones are reurbanised, derelict areas within the cities are being developedand degraded urban areas of derelict industrial complexes are being renaturalised. Inthe periphery combined research and production parks are being set up, in the open landscapeintegrated business, trade and recreational centres are springing up. Decentralisationand recentralisation of focal points of development accompany the contemporary processesof reurbanisation and suburbanisation – they are simultaneous and move in two-direction i.e. to and from the city. We understand them as manifestation of a dynamic balance amongcontradiction existing between the centre and the rim. Deindustrialisation and relocation ofproduction and distribution from the centres of gravity to the periphery generate extensivedegraded urban areas within cities and between the city and suburbs. The periphery is beingurbanised with the creation of new, dispersed and nonhierachical poles of development, andthe city and inner city is undergoing reurbanization. The general environmental conditionsin the city and in the countryside are being equalised, the potentials of development arebeing sought in the comparative advantages of local conditions: be it attractive urban districts,be it suburban entities or countryside areas.

  20. Databases of surface wave dispersion

    Directory of Open Access Journals (Sweden)

    L. Boschi

    2005-06-01

    Full Text Available Observations of seismic surface waves provide the most important constraint on the elastic properties of the Earth’s lithosphere and upper mantle. Two databases of fundamental mode surface wave dispersion were recently compiled and published by groups at Harvard (Ekström et al., 1997 and Utrecht/Oxford (Trampert and Woodhouse, 1995, 2001, and later employed in 3-d global tomographic studies. Although based on similar sets of seismic records, the two databases show some significant discrepancies. We derive phase velocity maps from both, and compare them to quantify the discrepancies and assess the relative quality of the data; in this endeavour, we take careful account of the effects of regularization and parametrization. At short periods, where Love waves are mostly sensitive to crustal structure and thickness, we refer our comparison to a map of the Earth’s crust derived from independent data. On the assumption that second-order effects like seismic anisotropy and scattering can be neglected, we find the measurements of Ekström et al. (1997 of better quality; those of Trampert and Woodhouse (2001 result in phase velocity maps of much higher spatial frequency and, accordingly, more difficult to explain and justify geophysically. The discrepancy is partly explained by the more conservative a priori selection of data implemented by Ekström et al. (1997. Nevertheless, it becomes more significant with decreasing period, which indicates that it could also be traced to the different measurement techniques employed by the authors.

  1. Pay Dispersion and Performance in Teams

    DEFF Research Database (Denmark)

    Bucciol, Alessandro; Foss, Nicolai J; Piovesan, Marco

    2014-01-01

    Extant research offers conflicting predictions about the effect of pay dispersion on team performance. We collected a unique dataset from the Italian soccer league to study the effect of intra-firm pay dispersion on team performance, under different definitions of what constitutes a "team". This ...

  2. A new optical rotation dispersion formula

    International Nuclear Information System (INIS)

    Kimel, I.

    1981-12-01

    A new dispersion formula for the rotatory power is obtained in the framework of Kubo forlalism for transport coefficients. Unlike the well known Rosenfeld-Condon dispersion law, this formula is consistent with the free electron gas asymptotic behavior. (Author) [pt

  3. Discrete dispersion models and their Tweedie asymptotics

    DEFF Research Database (Denmark)

    Jørgensen, Bent; Kokonendji, Célestin C.

    2016-01-01

    The paper introduce a class of two-parameter discrete dispersion models, obtained by combining convolution with a factorial tilting operation, similar to exponential dispersion models which combine convolution and exponential tilting. The equidispersed Poisson model has a special place in this ap......The paper introduce a class of two-parameter discrete dispersion models, obtained by combining convolution with a factorial tilting operation, similar to exponential dispersion models which combine convolution and exponential tilting. The equidispersed Poisson model has a special place...... in this approach, whereas several overdispersed discrete distributions, such as the Neyman Type A, Pólya-Aeppli, negative binomial and Poisson-inverse Gaussian, turn out to be Poisson-Tweedie factorial dispersion models with power dispersion functions, analogous to ordinary Tweedie exponential dispersion models...... with power variance functions. Using the factorial cumulant generating function as tool, we introduce a dilation operation as a discrete analogue of scaling, generalizing binomial thinning. The Poisson-Tweedie factorial dispersion models are closed under dilation, which in turn leads to a Poisson...

  4. Seed Dispersal Potential of Asian Elephants

    DEFF Research Database (Denmark)

    Harich, Franziska K.; Treydte, Anna Christina; Ogutu, Joseph Ochieng

    2016-01-01

    Elephants, the largest terrestrial mega-herbivores, play an important ecological role in maintaining forest ecosystem diversity. While several plant species strongly rely on African elephants (Loxodonta africana; L. cyclotis) as seed dispersers, little is known about the dispersal potential of As...

  5. Interspecific nematode signals regulate dispersal behavior.

    Directory of Open Access Journals (Sweden)

    Fatma Kaplan

    Full Text Available Dispersal is an important nematode behavior. Upon crowding or food depletion, the free living bacteriovorus nematode Caenorhabditis elegans produces stress resistant dispersal larvae, called dauer, which are analogous to second stage juveniles (J2 of plant parasitic Meloidogyne spp. and infective juveniles (IJs of entomopathogenic nematodes (EPN, e.g., Steinernema feltiae. Regulation of dispersal behavior has not been thoroughly investigated for C. elegans or any other nematode species. Based on the fact that ascarosides regulate entry in dauer stage as well as multiple behaviors in C. elegans adults including mating, avoidance and aggregation, we hypothesized that ascarosides might also be involved in regulation of dispersal behavior in C. elegans and for other nematodes such as IJ of phylogenetically related EPNs.Liquid chromatography-mass spectrometry analysis of C. elegans dauer conditioned media, which shows strong dispersing activity, revealed four known ascarosides (ascr#2, ascr#3, ascr#8, icas#9. A synthetic blend of these ascarosides at physiologically relevant concentrations dispersed C. elegans dauer in the presence of food and also caused dispersion of IJs of S. feltiae and J2s of plant parasitic Meloidogyne spp. Assay guided fractionation revealed structural analogs as major active components of the S. feltiae (ascr#9 and C. elegans (ascr#2 dispersal blends. Further analysis revealed ascr#9 in all Steinernema spp. and Heterorhabditis spp. infected insect host cadavers.Ascaroside blends represent evolutionarily conserved, fundamentally important communication systems for nematodes from diverse habitats, and thus may provide sustainable means for control of parasitic nematodes.

  6. 21 CFR 178.3725 - Pigment dispersants.

    Science.gov (United States)

    2010-04-01

    ... HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: ADJUVANTS, PRODUCTION AIDS, AND SANITIZERS Certain Adjuvants and Production Aids § 178.3725 Pigment dispersants. Subject to the provisions of this... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Pigment dispersants. 178.3725 Section 178.3725 Food...

  7. Dispersions of Carbon nanotubes in Polymer Matrices

    Science.gov (United States)

    Wise, Kristopher Eric (Inventor); Park, Cheol (Inventor); Siochi, Emilie J. (Inventor); Harrison, Joycelyn S. (Inventor); Lillehei, Peter T. (Inventor); Lowther, Sharon E. (Inventor)

    2010-01-01

    Dispersions of carbon nanotubes exhibiting long term stability are based on a polymer matrix having moieties therein which are capable of a donor-acceptor complexation with carbon nanotubes. The carbon nanotubes are introduced into the polymer matrix and separated therein by standard means. Nanocomposites produced from these dispersions are useful in the fabrication of structures, e.g., lightweight aerospace structures.

  8. Membranes as separators of dispersed emulsion phases

    NARCIS (Netherlands)

    Lefferts, A.G.

    1997-01-01

    The reuse or discharge of industrial waste waters, containing small fractions of dispersed oil, requires a purification treatment for which membranes can be used. If only little oil is present, removal of the dispersed phase might be preferable to the more commonly applied removal of the

  9. A synthesis of empirical plant dispersal kernels

    Czech Academy of Sciences Publication Activity Database

    Bullock, J. M.; González, L. M.; Tamme, R.; Götzenberger, Lars; White, S. M.; Pärtel, M.; Hooftman, D. A. P.

    2017-01-01

    Roč. 105, č. 1 (2017), s. 6-19 ISSN 0022-0477 Institutional support: RVO:67985939 Keywords : dispersal kernel * dispersal mode * probability density function Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 5.813, year: 2016

  10. Interaction between molecular complexes in dispersive media

    International Nuclear Information System (INIS)

    Banagas, E.A.; Manykin, E.A.

    1987-01-01

    The interaction between molecular complexes in different dispersive media with local and nonlocal screening is investigated theoretically. On the basis of results of numerical analysis on a computer, the dependence of the coupled-system spectrum and the interaction energy of the polarized modes on the characteristic parameters of the dispersive media is considered

  11. Modeling of atmospheric dispersion of radionuclides

    International Nuclear Information System (INIS)

    Baklouti, Nada

    2010-01-01

    This work is a prediction of atmospheric dispersion of radionuclide from a chronic rejection of the nuclear power generating plant that can be located in one of the Tunisian sites: Skhira or Bizerte. Also it contains a study of acute rejection 'Chernobyl accident' which was the reference for the validation of GENII the code of modeling of atmospheric dispersion.

  12. Dispersion-induced nonlinearities in semiconductors

    DEFF Research Database (Denmark)

    Mørk, Jesper; Mecozzi, A.

    2002-01-01

    A dispersive and saturable medium is shown, under very general conditions, to possess ultrafast dynamic behaviour due to non-adiabatic polarisation dynamics. Simple analytical expressions relating the effect to the refractive index dispersion of a semiconductor ire derived and the magnitude...... of the equivalent Kerr coefficient is shown to be in qualitative agreement with measurements on active semiconductor waveguides....

  13. Modeling the dispersal of spiny lobster (

    NARCIS (Netherlands)

    Whomersley, P.; van der Molen, J.; Holt, D.; Trundle, C.; Clark, S.; Fletcher, D.

    2018-01-01

    Knowledge of larval dispersal, population dynamics and connectivity in relation to the management and conservation of commercially important species is vital if existing fisheries are to remain sustainable into the future. Larval dispersal of the commercially exploited spiny lobster, Palinurus

  14. Employment Effects of Spatial Dispersal of Refugees

    DEFF Research Database (Denmark)

    Damm, Anna Piil; Rosholm, Michael

    We argue that spatial dispersal influences labour market assimilation of refugees through two mechanisms: first, the local job offer arrival rate and, second, place utility. Our partial search model with simultaneous job and residential location search predicts that the reservation wage for local...... by evaluating the employment effects of the Danish spatial dispersal policy carried out 1986-1998....

  15. An atmospheric dispersion index for prescribed burning

    Science.gov (United States)

    Leonidas G. Lavdas

    1986-01-01

    A numerical index that estimates the atmosphere's capacity to disperse smoke from prescribed burning is described. The physical assumptions and mathematical development of the index are given in detail. A preliminary interpretation of dispersion index values is offered. A FORTRAN subroutine package for computing the index is included.

  16. Dispersive and erodible soils - fundamental differences

    CSIR Research Space (South Africa)

    Paige-Green, P

    2008-11-01

    Full Text Available Dispersive, erodible and slaking soils are prevalent over wide areas of South Africa. Each of these materials increases the cost of construction, but dispersive soils are likely to lead to far more serious problems, particularly in dam construction...

  17. Spectral dispersion and fringe detection in IOTA

    Science.gov (United States)

    Traub, W. A.; Lacasse, M. G.; Carleton, N. P.

    1990-01-01

    Pupil plane beam combination, spectral dispersion, detection, and fringe tracking are discussed for the IOTA interferometer. A new spectrometer design is presented in which the angular dispersion with respect to wavenumber is nearly constant. The dispersing element is a type of grism, a series combination of grating and prism, in which the constant parts of the dispersion add, but the slopes cancel. This grism is optimized for the display of channelled spectra. The dispersed fringes can be tracked by a matched-filter photon-counting correlator algorithm. This algorithm requires very few arithmetic operations per detected photon, making it well-suited for real-time fringe tracking. The algorithm is able to adapt to different stellar spectral types, intensity levels, and atmospheric time constants. The results of numerical experiments are reported.

  18. Pay Dispersion and Performance in Teams

    Science.gov (United States)

    Bucciol, Alessandro; Foss, Nicolai J.; Piovesan, Marco

    2014-01-01

    Extant research offers conflicting predictions about the effect of pay dispersion on team performance. We collected a unique dataset from the Italian soccer league to study the effect of intra-firm pay dispersion on team performance, under different definitions of what constitutes a “team”. This peculiarity of our dataset can explain the conflicting evidence. Indeed, we also find positive, null, and negative effects of pay dispersion on team performance, using the same data but different definitions of team. Our results show that when the team is considered to consist of only the members who directly contribute to the outcome, high pay dispersion has a detrimental impact on team performance. Enlarging the definition of the team causes this effect to disappear or even change direction. Finally, we find that the detrimental effect of pay dispersion is due to worse individual performance, rather than a reduction of team cooperation. PMID:25397615

  19. Analysis of site-specific dispersion conditions

    International Nuclear Information System (INIS)

    Paesler-Sauer, J.

    1989-03-01

    This report presents an analysis of atmospheric dispersion conditions in the environs of nuclear power stations in the Federal Republic of Germany. The analysis is based on meteorological data measured on the power station sites (KFUe = nuclear reactor remote control records) and by neighbouring stations operated by the German Weather Service. The data are series of hourly mean values of wind and temperature gradient or stability class over the period of one or more years. The aim of the data analysis is to find types of dispersion conditions characterized by the flow field and stratification, and to assess the feasibility of calculating these quantities in the case of an emergency. Influences of terrain structures in the environs of the site are considered. The annual frequencies of types of dispersion situations are assessed, the capability to recognize the dispersion situation from meteorological data measured on the site and the applicability of dispersion models are discussed. (orig.) [de

  20. Solitonic Dispersive Hydrodynamics: Theory and Observation

    Science.gov (United States)

    Maiden, Michelle D.; Anderson, Dalton V.; Franco, Nevil A.; El, Gennady A.; Hoefer, Mark A.

    2018-04-01

    Ubiquitous nonlinear waves in dispersive media include localized solitons and extended hydrodynamic states such as dispersive shock waves. Despite their physical prominence and the development of thorough theoretical and experimental investigations of each separately, experiments and a unified theory of solitons and dispersive hydrodynamics are lacking. Here, a general soliton-mean field theory is introduced and used to describe the propagation of solitons in macroscopic hydrodynamic flows. Two universal adiabatic invariants of motion are identified that predict trapping or transmission of solitons by hydrodynamic states. The result of solitons incident upon smooth expansion waves or compressive, rapidly oscillating dispersive shock waves is the same, an effect termed hydrodynamic reciprocity. Experiments on viscous fluid conduits quantitatively confirm the soliton-mean field theory with broader implications for nonlinear optics, superfluids, geophysical fluids, and other dispersive hydrodynamic media.

  1. Connecting today's climates to future climate analogs to facilitate movement of species under climate change.

    Science.gov (United States)

    Littlefield, Caitlin E; McRae, Brad H; Michalak, Julia L; Lawler, Joshua J; Carroll, Carlos

    2017-12-01

    Increasing connectivity is an important strategy for facilitating species range shifts and maintaining biodiversity in the face of climate change. To date, however, few researchers have included future climate projections in efforts to prioritize areas for increasing connectivity. We identified key areas likely to facilitate climate-induced species' movement across western North America. Using historical climate data sets and future climate projections, we mapped potential species' movement routes that link current climate conditions to analogous climate conditions in the future (i.e., future climate analogs) with a novel moving-window analysis based on electrical circuit theory. In addition to tracing shifting climates, the approach accounted for landscape permeability and empirically derived species' dispersal capabilities. We compared connectivity maps generated with our climate-change-informed approach with maps of connectivity based solely on the degree of human modification of the landscape. Including future climate projections in connectivity models substantially shifted and constrained priority areas for movement to a smaller proportion of the landscape than when climate projections were not considered. Potential movement, measured as current flow, decreased in all ecoregions when climate projections were included, particularly when dispersal was limited, which made climate analogs inaccessible. Many areas emerged as important for connectivity only when climate change was modeled in 2 time steps rather than in a single time step. Our results illustrate that movement routes needed to track changing climatic conditions may differ from those that connect present-day landscapes. Incorporating future climate projections into connectivity modeling is an important step toward facilitating successful species movement and population persistence in a changing climate. © 2017 Society for Conservation Biology.

  2. Habitat selection and post-release movement of reintroduced brown treecreeper individuals in restored temperate woodland.

    Directory of Open Access Journals (Sweden)

    Victoria A Bennett

    Full Text Available It is essential to choose suitable habitat when reintroducing a species into its former range. Habitat quality may influence an individual's dispersal decisions and also ultimately where they choose to settle. We examined whether variation in habitat quality (quantified by the level of ground vegetation cover and the installation of nest boxes influenced the movement, habitat choice and survival of a reintroduced bird species. We experimentally reintroduced seven social groups (43 individuals of the brown treecreeper (Climacteris picumnus into two nature reserves in south-eastern Australia. We radio-tracked 18 brown treecreepers from release in November 2009 until February 2010. We observed extensive movements by individuals irrespective of the release environment or an individual's gender. This indicated that individuals were capable of dispersing and actively selecting optimum habitat. This may alleviate pressure on wildlife planners to accurately select the most optimum release sites, so long as the species' requirements are met. There was significant variation in movement between social groups, suggesting that social factors may be a more important influence on movement than habitat characteristics. We found a significant effect of ground vegetation cover on the likelihood of settlement by social groups, with high rates of settlement and survival in dry forests, rather than woodland (where the species typically resides, which has implications for the success of woodland restoration. However, overall the effects of variation in habitat quality were not as strong as we had expected, and resulted in some unpredicted effects such as low survival and settlement in woodland areas with medium levels of ground vegetation cover. The extensive movement by individuals and unforeseen effects of habitat characteristics make it difficult to predict the outcome of reintroductions, the movement behaviour and habitat selection of reintroduced individuals

  3. Deriving Animal Movement Behaviors Using Movement Parameters Extracted from Location Data

    Directory of Open Access Journals (Sweden)

    Maryam Teimouri

    2018-02-01

    Full Text Available We present a methodology for distinguishing between three types of animal movement behavior (foraging, resting, and walking based on high-frequency tracking data. For each animal we quantify an individual movement path. A movement path is a temporal sequence consisting of the steps through space taken by an animal. By selecting a set of appropriate movement parameters, we develop a method to assess movement behavioral states, reflected by changes in the movement parameters. The two fundamental tasks of our study are segmentation and clustering. By segmentation, we mean the partitioning of the trajectory into segments, which are homogeneous in terms of their movement parameters. By clustering, we mean grouping similar segments together according to their estimated movement parameters. The proposed method is evaluated using field observations (done by humans of movement behavior. We found that on average, our method agreed with the observational data (ground truth at a level of 80.75% ± 5.9% (SE.

  4. Genetic evidence for landscape effects on dispersal in the army ant Eciton burchellii.

    Science.gov (United States)

    Soare, Thomas W; Kumar, Anjali; Naish, Kerry A; O'Donnell, Sean

    2014-01-01

    Inhibited dispersal, leading to reduced gene flow, threatens populations with inbreeding depression and local extinction. Fragmentation may be especially detrimental to social insects because inhibited gene flow has important consequences for cooperation and competition within and among colonies. Army ants have winged males and permanently wingless queens; these traits imply male-biased dispersal. However, army ant colonies are obligately nomadic and have the potential to traverse landscapes. Eciton burchellii, the most regularly nomadic army ant, is a forest interior species: colony raiding activities are limited in the absence of forest cover. To examine whether nomadism and landscape (forest clearing and elevation) affect population genetic structure in a montane E. burchellii population, we reconstructed queen and male genotypes from 25 colonies at seven polymorphic microsatellite loci. Pairwise genetic distances among individuals were compared to pairwise geographical and resistance distances using regressions with permutations, partial Mantel tests and random forests analyses. Although there was no significant spatial genetic structure in queens or males in montane forest, dispersal may be male-biased. We found significant isolation by landscape resistance for queens based on land cover (forest clearing), but not on elevation. Summed colony emigrations over the lifetime of the queen may contribute to gene flow in this species and forest clearing impedes these movements and subsequent gene dispersal. Further forest cover removal may increasingly inhibit Eciton burchellii colony dispersal. We recommend maintaining habitat connectivity in tropical forests to promote population persistence for this keystone species. © 2013 John Wiley & Sons Ltd.

  5. The Anti-Doping Movement.

    Science.gov (United States)

    Willick, Stuart E; Miller, Geoffrey D; Eichner, Daniel

    2016-03-01

    Historical reports of doping in sports date as far back as the ancient Greek Olympic Games. The anti-doping community considers doping in sports to be cheating and a violation of the spirit of sport. During the past century, there has been an increasing awareness of the extent of doping in sports and the health risks of doping. In response, the anti-doping movement has endeavored to educate athletes and others about the health risks of doping and promote a level playing field. Doping control is now undertaken in most countries around the world and at most elite sports competitions. As athletes have found new ways to dope, however, the anti-doping community has endeavored to strengthen its educational and deterrence efforts. It is incumbent upon sports medicine professionals to understand the health risks of doping and all doping control processes. Copyright © 2016 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

  6. Teaching Movement Activities as Performativity

    DEFF Research Database (Denmark)

    Jensen, Jens-Ole

    2017-01-01

    subjects the teaching style should be characterized by more variation and motivate the pupils. Research has shown that there is a correlation between physical activity and intellectual capital (e.g. educational attainment and academic performance), physical capital (e.g. physical fitness and reduction...... of the risk for diseases and risk factors) and emotional capital (e.g. fun, enjoyment and self-esteem) (Bailey, Hillman, Arent, & Petitpas, 2013). The school reform prescribes that all pupils from grade 1-9 must have at least 45 minutes of movement activities in average every day.Next to the well-known PE...... without prerequisites but part of discourses and at the same time individual interpretations of specific practices. The teaching role is something that is constantly produced and reproduced in the bodily interaction. Understanding teaching as performativity means that teachers are not acting in certain...

  7. Plant movements and climate warming

    DEFF Research Database (Denmark)

    De Frenne, Pieter; Coomes, David A.; De Schrijver, An

    2014-01-01

    environments can establish in nonlocal sites. •We assess the intraspecific variation in growth responses to nonlocal soils by planting a widespread grass of deciduous forests (Milium effusum) into an experimental common garden using combinations of seeds and soil sampled in 22 sites across its distributional...... range, and reflecting movement scenarios of up to 1600 km. Furthermore, to determine temperature and forest-structural effects, the plants and soils were experimentally warmed and shaded. •We found significantly positive effects of the difference between the temperature of the sites of seed and soil...... collection on growth and seedling emergence rates. Migrant plants might thus encounter increasingly favourable soil conditions while tracking the isotherms towards currently ‘colder’ soils. These effects persisted under experimental warming. Rising temperatures and light availability generally enhanced plant...

  8. The movement of solutes through aqueous fissures in porous rock

    International Nuclear Information System (INIS)

    Glueckauf, E.

    1980-06-01

    A mathematical treatment has been given for the movement of materials dissolved in water flowing through narrow fissures of a micro-porous substrate. As there is no water flow in these micro-pores, equilibrium between the aqueous solution and the micro-porous substrate proceeds only by diffusion, with the result that there arises a gross disequilibrium. Two major effects arise: first, the hold-up in the substrate - even when there is no adsorption taking place - is orders of magnitude larger than on non-porous substrate, and increases even further, if adsorption takes place. Secondly, dispersion caused by non-equilibrium is also orders of magnitude greater than dispersion arising from convection effects of the water flow in interconnecting fissures. As a result, the solutes arrive very much later at the end of the underground fissures, and in concentrations which are very much lower than have been calculated in previous modelling experiments. The significance of these effects is discussed in detail, and this can be helpful in the selection of sites for underground disposal of radioactive waste. It is now quite feasible to specify sites with conditions, where even solutes with minimal adsorption would not return to the surface within a million years, and where solutes of moderately strong adsorption would be effectively immobile. (author)

  9. UFOMOD - atmospheric dispersion and deposition

    International Nuclear Information System (INIS)

    Panitz, H.J.; Matzerath, C.; Paesler-Sauer, J.

    1989-10-01

    The report gives an introduction into the modelling of atmospheric dispersion and deposition which has been implemented in the new program system UFOMOD for assessing the consequences after nuclear accidents. According to the new structure of UFOMOD, different trajectory models with ranges of validity near to the site and at far distances are applied. Emphasis is laid on the description of the segmented plume model MUSEMET and its affilated submodels, being the removal of activity from the cloud by dry and wet deposition, and special effects like plume rise and the behaviour of plumes released into building wakes. In addition, the evaluation of γ-dose correction factors to take account of the finite extent of the radioactive plume in the near range (up to about 20 km) are described. Only brief introductions are given into the principles of the other models available: the puff model RIMPUFF, the long-range puff model MESOS, and the special straight-line Gaussian model ISOLA which are used if low-level long-duration releases are considered. To define starting times of weather sequences and the probabilities of occurrence of these sequences, it is convenient to perform stratified sampling. Therefore, the preprocessing program package METSAM has been developed to perform for generic ACAs a random sampling of weather sequences out off a population of classified weather conditions. The sampling procedure and a detailed input/output (I/O) description is presented and an additional appendix, respectively. A general overview on the I/O structure of MUSEMET as well as a brief user guide to run the KfK version of the MESOS code are also given in the appendix. (orig.) [de

  10. Parametric HMMs for Movement Recognition and Synthesis

    DEFF Research Database (Denmark)

    Herzog, Dennis; Krüger, Volker

    2009-01-01

    , we develop an exemplar-based parametric hidden Markov model (PHMM) that allows to represent movements of a particular type. Since we use model interpolation to reduce the necessary amount of training data, we had to develop a method to setup local models in a synchronized way. In our experiments we......A common problem in human movement recognition is the recognition of movements of a particular type (semantic). E.g., grasping movements have a particular semantic (grasping) but the actual movements usually have very different appearances due to, e.g., different grasping directions. In this paper...... to recover the movement type, and, e.g., the object position a human is pointing at. Our experiments show the flexibility of the PHMMs in terms of the amount of training data and its robustness in terms of noisy observation data. In addition, we compare our PHMM to an other kind of PHMM, which has been...

  11. Using movement behaviour to define biological seasons for woodland caribou

    Directory of Open Access Journals (Sweden)

    Tyler D. Rudolph

    2012-03-01

    Full Text Available Terrestrial mammals are strongly influenced by seasonal changes in environmental conditions. Studies of animal space use behaviour are therefore inherently seasonal in nature. We propose an individual-based quantitative method for identifying seasonal shifts in caribou movement behaviour and we demonstrate its use in determining the onset of the winter, spring dispersal, and calving seasons. Using pooled data for the population we demonstrate an alternate approach using polynomial regression with mixed effects. We then compare individual onset dates with population-based estimates and those adopted by expert consensus for our study area. Distributions of individual-based onset dates were normally distributed with prominent modes; however, there was considerable variation in individual onset times. Population-based estimates were closer to the peaks of individual estimates than were expert-based estimates, which fell outside the onetailed 90% and 95% sample quantiles of individually-fitted distributions for spring and winter, respectively. Both expertand population-based estimates were later for winter and earlier for both spring and calving than were individual-based estimates. We discuss the potential consequences of neglecting to corroborate conventionally used dates with observed seasonal trends in movement behaviour. In closing, we recommend researchers adopt an individual-based quantitative approach and a variable temporal window for data set extraction.

  12. Homogenization of Large-Scale Movement Models in Ecology

    Science.gov (United States)

    Garlick, M.J.; Powell, J.A.; Hooten, M.B.; McFarlane, L.R.

    2011-01-01

    A difficulty in using diffusion models to predict large scale animal population dispersal is that individuals move differently based on local information (as opposed to gradients) in differing habitat types. This can be accommodated by using ecological diffusion. However, real environments are often spatially complex, limiting application of a direct approach. Homogenization for partial differential equations has long been applied to Fickian diffusion (in which average individual movement is organized along gradients of habitat and population density). We derive a homogenization procedure for ecological diffusion and apply it to a simple model for chronic wasting disease in mule deer. Homogenization allows us to determine the impact of small scale (10-100 m) habitat variability on large scale (10-100 km) movement. The procedure generates asymptotic equations for solutions on the large scale with parameters defined by small-scale variation. The simplicity of this homogenization procedure is striking when compared to the multi-dimensional homogenization procedure for Fickian diffusion,and the method will be equally straightforward for more complex models. ?? 2010 Society for Mathematical Biology.

  13. Challenges of the movement of catalytic micromotors in blood.

    Science.gov (United States)

    Zhao, Guanjia; Viehrig, Marlitt; Pumera, Martin

    2013-05-21

    Catalytic microjet bubble-propelled engines have attracted a large amount of interest for their potential applications in biomedicine, environmental sciences and natural resources discovery. One of the current efforts in this field is focused on the search of biocompatible fuels. However, only a minimal amount of effort has been made to assess the challenges facing the movement of such devices in a real world environment, especially with regards to the components of blood and their interactions with the catalytic microjets. Herein, we will show the limitations on the movement of catalytic microengines prepared via the rolled-up, as well as the templated-electrochemical deposition method, in an artificial blood sample, due to the presence of two main components of animal blood: the cellular component (red blood cells in this study) and serum. We will show that the motion of catalytic microjets is only possible in highly diluted dispersions of the red blood cells and serum. This finding has a profound implication on the development of the whole field, where the components found in real environments have to be considered carefully, and issues arising from the presence of such components have to be resolved prior to deploying these devices in real world applications.

  14. Movement-based Interaction in Camera Spaces

    DEFF Research Database (Denmark)

    Eriksson, Eva; Riisgaard Hansen, Thomas; Lykke-Olesen, Andreas

    2006-01-01

    In this paper we present three concepts that address movement-based interaction using camera tracking. Based on our work with several movement-based projects we present four selected applications, and use these applications to leverage our discussion, and to describe our three main concepts space......, relations, and feedback. We see these as central for describing and analysing movement-based systems using camera tracking and we show how these three concepts can be used to analyse other camera tracking applications....

  15. Outcomes of Social Movements and Protest Activities

    OpenAIRE

    Giugni, Marco; Bosi, Lorenzo; Uba, Katrin

    2013-01-01

    Scholarship has left the study of the consequences of social movements in the background for a long time, focusing instead on movement emergence, characteristics, and dynamics. Since the mid-1970s, however, scholars have paid an increasing interest in how social movements and protest activities may produce change at various levels. The existing literature can be ordered according to the kind of consequence addressed. In this regard, one can roughly distinguish between political, biographical,...

  16. Natal Dispersal in the North Island Robin (Petroica longipes: the Importance of Connectivity in Fragmented Habitats

    Directory of Open Access Journals (Sweden)

    Askia K. Wittern

    2007-12-01

    Full Text Available Natal dispersal is an important component in bird population dynamics and can influence the persistence of local and metapopulations. We examined natal dispersal in the North Island robin (Petroica longipes, a sedentary bird species distributed in a fragmented forest habitat on Tiritiri Matangi Island, New Zealand. Earlier studies have shown that the only dispersal phase in this species takes place when juveniles leave their natal patch, and that juveniles who fail to find suitable habitat do not survive their first winter. These findings suggest that natal dispersal behavior in this species is important for population viability. We found that juveniles were highly affected by the fragmentation of the forest habitat, with patch occupancy being positively correlated with degree of connectivity of the landscape. Most juvenile movements (52.1% were observed between patches that were separated by less than 20 m. Juvenile North Island robins were found in all forest habitat types, including young and open stands. This suggests that the juveniles are not dependent on old forest stands during their dispersal phase. Based on these findings, we suggest that management of this regionally-threatened species should focus not only on maintaining populations in occupied patches and increasing the habitat quality of these patches, but also on protecting existing forest patches acting as corridors and creating new forest habitat among patches. This would greatly increase the viability of the species' metapopulations by increasing dispersal success between both unoccupied patches and subpopulations. Additionally, increased connectivity between forest patches could also be expected to increase the probability of successful dispersal of other threatened native species, many of which are also sensitive to the high degree of fragmentation of their habitats.

  17. The Braer incident: Dispersion in action

    International Nuclear Information System (INIS)

    Thomas, D.

    1993-01-01

    In January 1993, the tanker Braer foundered in the Shetland Islands and pollution from the cargo of 85,000 tonnes of Gullfaks crude oil was reported almost immediately. The tanker was battered by storm winds and finally broke up, spilling the remainder of its cargo into the bay at Garth's Ness. Dispersants were applied to the oil plumes, assisting the significant natural dispersion. Shoreline protection and cleanup activities included construction of spade dams and sorbent barriers. Oil concentrations in water, air, sediment, and fish were monitored. The sampling program undertaken during the spill period is described. Measured hydrocarbon concentrations in salmon farm areas were not observed to rise above 4 ppM. The high rates of dispersion make the Braer incident worthy of detailed study both in terms of understanding the mechanism of the dispersion process and also in assessing the environmental effects following high dispersed oil concentrations. Estimates of the spill's mass balance are provided for the bay at Garth's Ness, where the highest oil concentrations were observed, and along the 26 km of coastline which received the most significant concentrations of dispersed oil. Contrary to laboratory experiments which showed that the Gullfaks crude would emulsify at the high sea states prevailing at the time, the Braer spill did not emulsify and most of the oil released was dispersed naturally into the water column. It appears that it is most appropriate to model the Braer spill as a spillage of floating or dissolved chemical. 4 refs., 4 figs., 6 tabs

  18. Dispersion cancellation in a triple Laue interferometer

    International Nuclear Information System (INIS)

    Lemmel, Hartmut

    2014-01-01

    The concept of dispersion cancellation has been established in light optics to improve the resolution of interferometric measurements on dispersive media. Odd order dispersion cancellation allows to measure phase shifts without defocusing the interferometer due to wave packet displacements, while even order dispersion cancellation allows to measure time lags without losing resolution due to wave packet spreading. We report that either type of dispersion cancellation can be realized very easily in a triple Laue interferometer. Such interferometers are Mach–Zehnder interferometers based on Bragg diffraction, and are commonly used for neutrons and x-rays. Although the first x-ray interferometer was built nearly five decades ago, the feature of dispersion cancellation hasn't been recognized so far because the concept was hardly known in the neutron and x-ray community. However, it explains right away the surprising decoupling of phase shift and spatial displacement that we have discovered recently in neutron interferometry (Lemmel and Wagh 2010 Phys. Rev. A 82 033626). Furthermore, this article might inspire the light optics community to consider whether a triple Laue interferometer for laser light would be useful and feasible. We explain how dispersion cancellation works in neutron interferometry, and we describe the setup rigorously by solving the Schrödinger equation and by calculating the path integral. We point out, that the latter has to be evaluated with special care since in our setup the beam trajectory moves with respect to the crystal lattice of the interferometer. (paper)

  19. A minor conformation of a lanthanide tag on adenylate kinase characterized by paramagnetic relaxation dispersion NMR spectroscopy

    International Nuclear Information System (INIS)

    Hass, Mathias A. S.; Liu, Wei-Min; Agafonov, Roman V.; Otten, Renee; Phung, Lien A.; Schilder, Jesika T.; Kern, Dorothee; Ubbink, Marcellus

    2015-01-01

    NMR relaxation dispersion techniques provide a powerful method to study protein dynamics by characterizing lowly populated conformations that are in dynamic exchange with the major state. Paramagnetic NMR is a versatile tool for investigating the structures and dynamics of proteins. These two techniques were combined here to measure accurate and precise pseudocontact shifts of a lowly populated conformation. This method delivers valuable long-range structural restraints for higher energy conformations of macromolecules in solution. Another advantage of combining pseudocontact shifts with relaxation dispersion is the increase in the amplitude of dispersion profiles. Lowly populated states are often involved in functional processes, such as enzyme catalysis, signaling, and protein/protein interactions. The presented results also unveil a critical problem with the lanthanide tag used to generate paramagnetic relaxation dispersion effects in proteins, namely that the motions of the tag can interfere severely with the observation of protein dynamics. The two-point attached CLaNP-5 lanthanide tag was linked to adenylate kinase. From the paramagnetic relaxation dispersion only motion of the tag is observed. The data can be described accurately by a two-state model in which the protein-attached tag undergoes a 23° tilting motion on a timescale of milliseconds. The work demonstrates the large potential of paramagnetic relaxation dispersion and the challenge to improve current tags to minimize relaxation dispersion from tag movements

  20. Rapid diversification in Australia and two dispersals out of Australia in the globally distributed bee genus, Hylaeus (Colletidae: Hylaeinae).

    Science.gov (United States)

    Kayaalp, Pelin; Schwarz, Michael P; Stevens, Mark I

    2013-03-01

    Hylaeus is the only globally distributed colletid bee genus, with subgeneric and species-level diversity highest in Australia. We used one mitochondrial and two nuclear genes to reconstruct a phylogeny using Bayesian analyses of this genus based on species from Australia, Asia, Africa, Europe, Hawai'i, the New World and New Zealand. Our results concord with a ca. 30Mya Hylaeus crown age inferred by earlier studies, and we show that Hylaeus originated in Australia. Our phylogeny indicates only two dispersal events out of Australia, both shortly after the initial diversification of extant taxa. One of these dispersals was into New Zealand with only a minor subsequent radiation, but the second dispersal out of Australia resulted in a world-wide distribution. This second dispersal and radiation event, combined with very extensive early radiation of Hyleaus in Australia, poses a conundrum: what kinds of biogeographical and ecological factors could simultaneously drive global dispersal, yet strongly constrain further successful migrations out of Australia when geographical barriers appear to be weak? We argue that for hylaeine bees movement into new niches and enemy-free spaces may have favoured initial dispersal events, but that subsequent dispersals would not have entailed the original benefits of new niche space. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. Subthalamic nucleus detects unnatural android movement.

    Science.gov (United States)

    Ikeda, Takashi; Hirata, Masayuki; Kasaki, Masashi; Alimardani, Maryam; Matsushita, Kojiro; Yamamoto, Tomoyuki; Nishio, Shuichi; Ishiguro, Hiroshi

    2017-12-19

    An android, i.e., a realistic humanoid robot with human-like capabilities, may induce an uncanny feeling in human observers. The uncanny feeling about an android has two main causes: its appearance and movement. The uncanny feeling about an android increases when its appearance is almost human-like but its movement is not fully natural or comparable to human movement. Even if an android has human-like flexible joints, its slightly jerky movements cause a human observer to detect subtle unnaturalness in them. However, the neural mechanism underlying the detection of unnatural movements remains unclear. We conducted an fMRI experiment to compare the observation of an android and the observation of a human on which the android is modelled, and we found differences in the activation pattern of the brain regions that are responsible for the production of smooth and natural movement. More specifically, we found that the visual observation of the android, compared with that of the human model, caused greater activation in the subthalamic nucleus (STN). When the android's slightly jerky movements are visually observed, the STN detects their subtle unnaturalness. This finding suggests that the detection of unnatural movements is attributed to an error signal resulting from a mismatch between a visual input and an internal model for smooth movement.

  2. Airport Movement Area Closure Planner, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR research develops an automation tool improving temporary and permanent runway closure management. The Movement Area Closure Planner (MACP) provides airport...

  3. Generalized dispersive wave emission in nonlinear fiber optics.

    Science.gov (United States)

    Webb, K E; Xu, Y Q; Erkintalo, M; Murdoch, S G

    2013-01-15

    We show that the emission of dispersive waves in nonlinear fiber optics is not limited to soliton-like pulses propagating in the anomalous dispersion regime. We demonstrate, both numerically and experimentally, that pulses propagating in the normal dispersion regime can excite resonant dispersive radiation across the zero-dispersion wavelength into the anomalous regime.

  4. Degeneration of rapid eye movement sleep circuitry underlies rapid eye movement sleep behavior disorder.

    Science.gov (United States)

    McKenna, Dillon; Peever, John

    2017-05-01

    During healthy rapid eye movement sleep, skeletal muscles are actively forced into a state of motor paralysis. However, in rapid eye movement sleep behavior disorder-a relatively common neurological disorder-this natural process is lost. A lack of motor paralysis (atonia) in rapid eye movement sleep behavior disorder allows individuals to actively move, which at times can be excessive and violent. At first glance this may sound harmless, but it is not because rapid eye movement sleep behavior disorder patients frequently injure themselves or the person they sleep with. It is hypothesized that the degeneration or dysfunction of the brain stem circuits that control rapid eye movement sleep paralysis is an underlying cause of rapid eye movement sleep behavior disorder. The link between brain stem degeneration and rapid eye movement sleep behavior disorder stems from the fact that rapid eye movement sleep behavior disorder precedes, in the majority (∼80%) of cases, the development of synucleinopathies such as Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy, which are known to initially cause degeneration in the caudal brain stem structures where rapid eye movement sleep circuits are located. Furthermore, basic science and clinical evidence demonstrate that lesions within the rapid eye movement sleep circuits can induce rapid eye movement sleep-specific motor deficits that are virtually identical to those observed in rapid eye movement sleep behavior disorder. This review examines the evidence that rapid eye movement sleep behavior disorder is caused by synucleinopathic neurodegeneration of the core brain stem circuits that control healthy rapid eye movement sleep and concludes that rapid eye movement sleep behavior disorder is not a separate clinical entity from synucleinopathies but, rather, it is the earliest symptom of these disorders. © 2017 International Parkinson and Movement Disorder Society. © 2017 International Parkinson and

  5. A spatial simulation model for the dispersal of the bluetongue vector Culicoides brevitarsis in Australia.

    Directory of Open Access Journals (Sweden)

    Joel K Kelso

    Full Text Available The spread of Bluetongue virus (BTV among ruminants is caused by movement of infected host animals or by movement of infected Culicoides midges, the vector of BTV. Biologically plausible models of Culicoides dispersal are necessary for predicting the spread of BTV and are important for planning control and eradication strategies.A spatially-explicit simulation model which captures the two underlying population mechanisms, population dynamics and movement, was developed using extensive data from a trapping program for C. brevitarsis on the east coast of Australia. A realistic midge flight sub-model was developed and the annual incursion and population establishment of C. brevitarsis was simulated. Data from the literature was used to parameterise the model.The model was shown to reproduce the spread of C. brevitarsis southwards along the east Australian coastline in spring, from an endemic population to the north. Such incursions were shown to be reliant on wind-dispersal; Culicoides midge active flight on its own was not capable of achieving known rates of southern spread, nor was re-emergence of southern populations due to overwintering larvae. Data from midge trapping programmes were used to qualitatively validate the resulting simulation model.The model described in this paper is intended to form the vector component of an extended model that will also include BTV transmission. A model of midge movement and population dynamics has been developed in sufficient detail such that the extended model may be used to evaluate the timing and extent of BTV outbreaks. This extended model could then be used as a platform for addressing the effectiveness of spatially targeted vaccination strategies or animal movement bans as BTV spread mitigation measures, or the impact of climate change on the risk and extent of outbreaks. These questions involving incursive Culicoides spread cannot be simply addressed with non-spatial models.

  6. Anomalous dispersion enhanced Cerenkov phase-matching

    Energy Technology Data Exchange (ETDEWEB)

    Kowalczyk, T.C.; Singer, K.D. [Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Physics; Cahill, P.A. [Sandia National Labs., Albuquerque, NM (United States)

    1993-11-01

    The authors report on a scheme for phase-matching second harmonic generation in polymer waveguides based on the use of anomalous dispersion to optimize Cerenkov phase matching. They have used the theoretical results of Hashizume et al. and Onda and Ito to design an optimum structure for phase-matched conversion. They have found that the use of anomalous dispersion in the design results in a 100-fold enhancement in the calculated conversion efficiency. This technique also overcomes the limitation of anomalous dispersion phase-matching which results from absorption at the second harmonic. Experiments are in progress to demonstrate these results.

  7. Noise figure of amplified dispersive Fourier transformation

    International Nuclear Information System (INIS)

    Goda, Keisuke; Jalali, Bahram

    2010-01-01

    Amplified dispersive Fourier transformation (ADFT) is a powerful tool for fast real-time spectroscopy as it overcomes the limitations of traditional optical spectrometers. ADFT maps the spectrum of an optical pulse into a temporal waveform using group-velocity dispersion and simultaneously amplifies it in the optical domain. It greatly simplifies spectroscopy by replacing the diffraction grating and detector array in the conventional spectrometer with a dispersive fiber and single-pixel photodetector, enabling ultrafast real-time spectroscopic measurements. Following our earlier work on the theory of ADFT, here we study the effect of noise on ADFT. We derive the noise figure of ADFT and discuss its dependence on various parameters.

  8. Phase noise of dispersion-managed solitons

    International Nuclear Information System (INIS)

    Spiller, Elaine T.; Biondini, Gino

    2009-01-01

    We quantify noise-induced phase deviations of dispersion-managed solitons (DMS) in optical fiber communications and femtosecond lasers. We first develop a perturbation theory for the dispersion-managed nonlinear Schroedinger equation (DMNLSE) in order to compute the noise-induced mean and variance of the soliton parameters. We then use the analytical results to guide importance-sampled Monte Carlo simulations of the noise-driven DMNLSE. Comparison of these results with those from the original unaveraged governing equations confirms the validity of the DMNLSE as a model for many dispersion-managed systems and quantify the increased robustness of DMS with respect to noise-induced phase jitter.

  9. An expert system for dispersion model interpretation

    International Nuclear Information System (INIS)

    Skyllingstad, E.D.; Ramsdell, J.V.

    1988-10-01

    A prototype expert system designed to diagnose dispersion model uncertainty is described in this paper with application to a puff transport model. The system obtains qualitative information from the model user and through an expert-derived knowledge base, performs a rating of the current simulation. These results can then be used in combination with dispersion model output for deciding appropriate evacuation measures. Ultimately, the goal of this work is to develop an expert system that may be operated accurately by an individual uneducated in meteorology or dispersion modeling. 5 refs., 3 figs

  10. How landscape dynamics link individual- to population-level movement patterns: A multispecies comparison of ungulate relocation data

    Science.gov (United States)

    Mueller, Thomas; Olson, K.A.; Dressler, G.; Leimgruber, Peter; Fuller, Todd K.; Nicholson, Craig; Novaro, A.J.; Bolgeri, M.J.; Wattles, David W.; DeStefano, Stephen; Calabrese, J.M.; Fagan, William F.

    2011-01-01

    Aim  To demonstrate how the interrelations of individual movements form large-scale population-level movement patterns and how these patterns are associated with the underlying landscape dynamics by comparing ungulate movements across species.Locations  Arctic tundra in Alaska and Canada, temperate forests in Massachusetts, Patagonian Steppes in Argentina, Eastern Steppes in Mongolia.Methods  We used relocation data from four ungulate species (barren-ground caribou, Mongolian gazelle, guanaco and moose) to examine individual movements and the interrelation of movements among individuals. We applied and developed a suite of spatial metrics that measure variation in movement among individuals as population dispersion, movement coordination and realized mobility. Taken together, these metrics allowed us to quantify and distinguish among different large-scale population-level movement patterns such as migration, range residency and nomadism. We then related the population-level movement patterns to the underlying landscape vegetation dynamics via long-term remote sensing measurements of the temporal variability, spatial variability and unpredictability of vegetation productivity.Results  Moose, which remained in sedentary home ranges, and guanacos, which were partially migratory, exhibited relatively short annual movements associated with landscapes having very little broad-scale variability in vegetation. Caribou and gazelle performed extreme long-distance movements that were associated with broad-scale variability in vegetation productivity during the peak of the growing season. Caribou exhibited regular seasonal migration in which individuals were clustered for most of the year and exhibited coordinated movements. In contrast, gazelle were nomadic, as individuals were independently distributed and moved in an uncoordinated manner that relates to the comparatively unpredictable (yet broad-scale) vegetation dynamics of their landscape.Main conclusions

  11. Simple approach to detection and estimation of photoactivity of silver particles on graphene oxide in aqueous-organic dispersion

    Science.gov (United States)

    Vlasov, D. V.; Vlasova, T. D.; Apresyan, L. A.; Krasovskiy, V. I.; Feofanov, I. N.; Kazaryan, M. A.

    2015-12-01

    The effect of sediment flotation was observed in dispersion of graphene oxide flakes with Ag-particles deposited thereon in the aqueous-organic (containing dimethylformamide) under the visible light action, with subsequent stabilization of the dispersion, which does not occur in the absence of Ag-particles. The main reason for this laser light induced movement of sediment graphene oxide flakes may be associated with the appearance of small bubbles. The further development of this approach seem to be able to estimate the of graphene flakes photoactivity with different activating particles.

  12. Removal of Disperse Blue 56 and Disperse Red 135 dyes from aqueous dispersions by modified montmorillonite nanoclay

    Directory of Open Access Journals (Sweden)

    Ahmadishoar Javad

    2017-01-01

    Full Text Available In this study modified montmorillonite was used as an adsorbent for the removal of two selected disperse dyes i.e., Disperse Blue 56 (DB and Disperse Red 135 (DR from dye dispersions. The adsorption equilibrium data of dyes adsorption were investigated by using Nernst, Freundlich and Langmuir isotherm models. The adsorption kinetics was analyzed by using different models including pseudo-first-order, pseudo-second-order, Elovich and Intraparticle diffusion model. The Freundlich isotherm was found to be the most appropriate model for describing the sorption of the dyes on modified nanoclay. The best fit to the experimental results was obtained by using the pseudo-second-order kinetic equation, which satisfactorily described the process of dye adsorption. Although different kinetic models may control the rate of the adsorption process, the results indicated that the main rate limiting step was the intraparticle diffusion. The results showed that the proposed modified montmorillonite could be used as an effective adsorbent for the removal of disperse dyes even from highly concentrated dispersions.

  13. Potential spread of highly pathogenic avian influenza H5N1 by wildfowl: dispersal ranges and rates determined from large-scale satellite telemetry

    Science.gov (United States)

    Gaidet, Nicolas; Cappelle, Julien; Takekawa, John Y.; Prosser, Diann J.; Iverson, Samuel A.; Douglas, David C.; Perry, William M.; Mundkur, Taej; Newman, Scott H.

    2010-01-01

    1. Migratory birds are major candidates for long-distance dispersal of zoonotic pathogens. In recent years, wildfowl have been suspected of contributing to the rapid geographic spread of the highly pathogenic avian influenza (HPAI) H5N1 virus. Experimental infection studies reveal that some wild ducks, geese and swans shed this virus asymptomatically and hence have the potential to spread it as they move. 2. We evaluate the dispersive potential of HPAI H5N1 viruses by wildfowl through an analysis of the movement range and movement rate of birds monitored by satellite telemetry in relation to the apparent asymptomatic infection duration (AID) measured in experimental studies. We analysed the first large-scale data set of wildfowl movements, including 228 birds from 19 species monitored by satellite telemetry in 2006–2009, over HPAI H5N1 affected regions of Asia, Europe and Africa. 3. Our results indicate that individual migratory wildfowl have the potential to disperse HPAI H5N1 over extensive distances, being able to perform movements of up to 2900 km within timeframes compatible with the duration of asymptomatic infection. 4. However, the likelihood of such virus dispersal over long distances by individual wildfowl is low: we estimate that for an individual migratory bird there are, on average, only 5–15 days per year when infection could result in the dispersal of HPAI H5N1 virus over 500 km. 5. Staging at stopover sites during migration is typically longer than the period of infection and viral shedding, preventing birds from dispersing a virus over several consecutive but interrupted long-distance movements. Intercontinental virus dispersion would therefore probably require relay transmission between a series of successively infected migratory birds. 6. Synthesis and applications. Our results provide a detailed quantitative assessment of the dispersive potential of HPAI H5N1 virus by selected migratory birds. Such dispersive potential rests on the

  14. Fetal Eye Movements on Magnetic Resonance Imaging

    Science.gov (United States)

    Woitek, Ramona; Kasprian, Gregor; Lindner, Christian; Stuhr, Fritz; Weber, Michael; Schöpf, Veronika; Brugger, Peter C.; Asenbaum, Ulrika; Furtner, Julia; Bettelheim, Dieter; Seidl, Rainer; Prayer, Daniela

    2013-01-01

    Objectives Eye movements are the physical expression of upper fetal brainstem function. Our aim was to identify and differentiate specific types of fetal eye movement patterns using dynamic MRI sequences. Their occurrence as well as the presence of conjugated eyeball motion and consistently parallel eyeball position was systematically analyzed. Methods Dynamic SSFP sequences were acquired in 72 singleton fetuses (17–40 GW, three age groups [17–23 GW, 24–32 GW, 33–40 GW]). Fetal eye movements were evaluated according to a modified classification originally published by Birnholz (1981): Type 0: no eye movements; Type I: single transient deviations; Type Ia: fast deviation, slower reposition; Type Ib: fast deviation, fast reposition; Type II: single prolonged eye movements; Type III: complex sequences; and Type IV: nystagmoid. Results In 95.8% of fetuses, the evaluation of eye movements was possible using MRI, with a mean acquisition time of 70 seconds. Due to head motion, 4.2% of the fetuses and 20.1% of all dynamic SSFP sequences were excluded. Eye movements were observed in 45 fetuses (65.2%). Significant differences between the age groups were found for Type I (p = 0.03), Type Ia (p = 0.031), and Type IV eye movements (p = 0.033). Consistently parallel bulbs were found in 27.3–45%. Conclusions In human fetuses, different eye movement patterns can be identified and described by MRI in utero. In addition to the originally classified eye movement patterns, a novel subtype has been observed, which apparently characterizes an important step in fetal brainstem development. We evaluated, for the first time, eyeball position in fetuses. Ultimately, the assessment of fetal eye movements by MRI yields the potential to identify early signs of brainstem dysfunction, as encountered in brain malformations such as Chiari II or molar tooth malformations. PMID:24194885

  15. Fetal eye movements on magnetic resonance imaging.

    Science.gov (United States)

    Woitek, Ramona; Kasprian, Gregor; Lindner, Christian; Stuhr, Fritz; Weber, Michael; Schöpf, Veronika; Brugger, Peter C; Asenbaum, Ulrika; Furtner, Julia; Bettelheim, Dieter; Seidl, Rainer; Prayer, Daniela

    2013-01-01

    Eye movements are the physical expression of upper fetal brainstem function. Our aim was to identify and differentiate specific types of fetal eye movement patterns using dynamic MRI sequences. Their occurrence as well as the presence of conjugated eyeball motion and consistently parallel eyeball position was systematically analyzed. Dynamic SSFP sequences were acquired in 72 singleton fetuses (17-40 GW, three age groups [17-23 GW, 24-32 GW, 33-40 GW]). Fetal eye movements were evaluated according to a modified classification originally published by Birnholz (1981): Type 0: no eye movements; Type I: single transient deviations; Type Ia: fast deviation, slower reposition; Type Ib: fast deviation, fast reposition; Type II: single prolonged eye movements; Type III: complex sequences; and Type IV: nystagmoid. In 95.8% of fetuses, the evaluation of eye movements was possible using MRI, with a mean acquisition time of 70 seconds. Due to head motion, 4.2% of the fetuses and 20.1% of all dynamic SSFP sequences were excluded. Eye movements were observed in 45 fetuses (65.2%). Significant differences between the age groups were found for Type I (p = 0.03), Type Ia (p = 0.031), and Type IV eye movements (p = 0.033). Consistently parallel bulbs were found in 27.3-45%. In human fetuses, different eye movement patterns can be identified and described by MRI in utero. In addition to the originally classified eye movement patterns, a novel subtype has been observed, which apparently characterizes an important step in fetal brainstem development. We evaluated, for the first time, eyeball position in fetuses. Ultimately, the assessment of fetal eye movements by MRI yields the potential to identify early signs of brainstem dysfunction, as encountered in brain malformations such as Chiari II or molar tooth malformations.

  16. Dispersion, sorption and photodegradation of petroleum hydrocarbons in dispersant-seawater-sediment systems.

    Science.gov (United States)

    Zhao, Xiao; Liu, Wen; Fu, Jie; Cai, Zhengqing; O'Reilly, S E; Zhao, Dongye

    2016-08-15

    This work examined effects of model oil dispersants on dispersion, sorption and photodegradation of petroleum hydrocarbons in simulated marine systems. Three dispersants (Corexit 9500A, Corexit 9527A and SPC 1000) were used to prepare dispersed water accommodated oil (DWAO). While higher doses of dispersants dispersed more n-alkanes and PAHs, Corexit 9500A preferentially dispersed C11-C20 n-alkanes, whereas Corexit 9527A was more favorable for smaller alkanes (C10-C16), and SPC 1000 for C12-C28 n-alkanes. Sorption of petroleum hydrocarbons on sediment was proportional to TPH types/fractions in the DWAOs. Addition of 18mg/L of Corexit 9500A increased sediment uptake of 2-3 ring PAHs, while higher dispersant doses reduced the uptake, due to micelle-enhanced solubilization effects. Both dispersed n-alkanes and PAHs were susceptible to photodegradation under simulated sunlight. For PAHs, both photodegradation and photo-facilitated alkylation were concurrently taking place. The information can facilitate sounder assessment of fate and distribution of dispersed oil hydrocarbons in marine systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Effects of chemical dispersants on oil physical properties and dispersion. Volume 1

    International Nuclear Information System (INIS)

    Khelifa, A.; Fingas, M.; Hollebone, B.P.; Brown, C.E.; Pjontek, D.

    2007-01-01

    Laboratory and field testing have shown that the dispersion of oil spilled in water is influenced by chemical dispersants via the modification of the interfacial properties of the oil, such as oil-brine interfacial tension (IFT). This study focused on new laboratory experiments that measured the effects on the physical properties and dispersion of oil, with particular reference to the effects of chemical dispersants on IFT and oil viscosity and the subsequent effects on oil droplet formation. Experiments were conducted at 15 degrees C using Arabian Medium, Alaska North Slope and South Louisiana crude and Corexit 9500 and Corexit 9527 chemical dispersants. The dispersants were denser than the 3 oils. The effect of IFT reduction on oil dispersion was measured and showed substantial reduction in the size and enhancement of the concentration of oil droplets in the water column. It was shown that the brine-oil IFT associated with the 3 crudes reduced to less than 3.6 mN/m with the application of the chemical dispersants, even at a low dispersant-to-oil ratio (DOR) value of 1:200. The use of chemical dispersants increased the viscosity of the dispersant-oil mixture up to 40 per cent over the neat crude oil. It was shown that for each mixing condition, an optimum value of DOR exists that provides for maximal dispersant effectiveness. The IFT reaches maximum reduction at optimum DOR. It was suggested that oil spill modelling can be improved with further study of IFT reduction with DOR and variations of critical micelle concentration with the type and solubility of chemical dispersant, oil type and oil to water ratio. 13 refs., 3 tabs., 7 figs

  18. Dispersal Timing: Emigration of Insects Living in Patchy Environments.

    Directory of Open Access Journals (Sweden)

    Milica Lakovic

    Full Text Available Dispersal is a life-history trait affecting dynamics and persistence of populations; it evolves under various known selective pressures. Theoretical studies on dispersal typically assume 'natal dispersal', where individuals emigrate right after birth. But emigration may also occur during a later moment within a reproductive season ('breeding dispersal'. For example, some female butterflies first deposit eggs in their natal patch before migrating to other site(s to continue egg-laying there. How breeding compared to natal dispersal influences the evolution of dispersal has not been explored. To close this gap we used an individual-based simulation approach to analyze (i the evolution of timing of breeding dispersal in annual organisms, (ii its influence on dispersal (compared to natal dispersal. Furthermore, we tested (iii its performance in direct evolutionary contest with individuals following a natal dispersal strategy. Our results show that evolution should typically result in lower dispersal under breeding dispersal, especially when costs of dispersal are low and population size is small. By distributing offspring evenly across two patches, breeding dispersal allows reducing direct sibling competition in the next generation whereas natal dispersal can only reduce trans-generational kin competition by producing highly dispersive offspring in each generation. The added benefit of breeding dispersal is most prominent in patches with small population sizes. Finally, the evolutionary contests show that a breeding dispersal strategy would universally out-compete natal dispersal.

  19. FUNCTIONAL MOVEMENT SCREENING: THE USE OF FUNDAMENTAL MOVEMENTS AS AN ASSESSMENT OF FUNCTION ‐ PART 1

    OpenAIRE

    Cook, Gray; Burton, Lee; Hoogenboom, Barbara J.; Voight, Michael

    2014-01-01

    To prepare an athlete for the wide variety of activities needed to participate in or return to their sport, the analysis of fundamental movements should be incorporated into screening in order to determine who possesses, or lacks, the ability to perform certain essential movements. In a series of two articles, the background and rationale for the analysis of fundamental movement will be provided. The Functional Movement Screen (FMS™) will be described, and any evidence related to its use will...

  20. THE INFLUENCE OF LOWER LIMB MOVEMENT ON UPPER LIMB MOVEMENT SYMMETRY WHILE SWIMMING THE BREASTSTROKE

    OpenAIRE

    M. Jaszczak

    2011-01-01

    This study 1) examined the influence of lower limb movement on upper limb movement symmetry, 2) determined the part of the propulsion phase displaying the greatest hand movement asymmetry, 3) diagnosed the range of upper limb propulsion phase which is the most prone to the influence of the lower limbs while swimming the breaststroke. Twenty-four participants took part in two tests. Half of them performed an asymmetrical leg movement. The propulsion in the first test was generated by four limb...

  1. The Dangers of Dispersal of Responsibilities

    Directory of Open Access Journals (Sweden)

    Adriana Schiopoiu Burlea

    2017-05-01

    Full Text Available Taking into account that it is in the nature of the modern corporation that risks are distributed over several agents, we discuss in this paper the organisational behaviour as it results from such dispersal of responsibilities for both the principal and the agent. We explore the hypothesis that dispersal of responsibilities could be the result or a cause of a lack of consensus between the principal and the agent. Our findings suggest that a dispersal of responsibilities has a negative impact on the principal-agent relationship and that it represents a foundation for theoretical and empirical approaches to organisational behaviour. We find that agent perceptions of a dispersal of responsibilities are linked to his/her resistance to the principal’s interests, but this relationship is deeper than was suggested by previous research. However, if the sharing of responsibilities does not run parallel to that, we may have as a result what we call an agency problem.

  2. Adsorption of an anionic dispersant on lignite

    Energy Technology Data Exchange (ETDEWEB)

    Yavuz, R.; Kucukbayrak, S. [Istanbul Technical University, Istanbul (Turkey). Dept. of Chemical Engineering, Chemical & Metallurgical Engineering Faculty

    2001-12-01

    Since coal is not a homogeneous substance but a mixture of carbonaceous materials and mineral matter, it has a variety of surface properties. Therefore, it is not easy to control the properties of coal suspensions by simply adjusting variables, such as pH and/or electrolyte. A chemical agent needs to be added to control the properties of the coal suspensions. The adsorption behavior of an anionic dispersant in the presence of a wetting agent using some Turkish lignite samples was investigated. The effects of dispersant concentration, temperature and pH on the dispersant adsorption were studied systematically, and the experimental results are presented. Pellupur B69 as a dispersant, commercial mixture of formaldehyde condensate sodium salt of naphthalene sulphonic acid, and Texapon N{sub 2}5 as a wetting agent, a sodium lauryl ether sulfate, have been used.

  3. Dispersion engineering in metamaterials and metasurfaces

    Science.gov (United States)

    Li, Xiong; Pu, Mingbo; Ma, Xiaoliang; Guo, Yinghui; Gao, Ping; Luo, Xiangang

    2018-02-01

    Dispersion engineering is essential for spectral utilization in electromagnetic systems. However, it is difficult to manage the dispersions in both natural materials and traditional electromagnetic waveguides since they are tightly related to fine structures of atoms, molecules and causality. The emergence of metamaterials and metasurfaces, which are made of subwavelength inclusions offers tremendous freedom to manipulate the electromagnetic parameters of materials and modes. Here, we review the basic principles, practical applications and recent advancements of the dispersion engineering in metadevices. The contributions of dispersion management in metadevice-based super-resolution imaging/nanolithography systems, planar functional devices, as well as the broadband perfect absorbers/polarization converters are discussed in depth. The challenges faced by this field as well as future developing trends are also presented in the conclusions.

  4. PETROLEUM-COLLECTING AND DISPERSING CHEMICALS FOR ...

    African Journals Online (AJOL)

    Preferred Customer

    Films of petroleum origin reflecting sunlight rays hinder absorption of energy by water necessary for life ... Dispersing chemicals like mechanical clean-up methods have their own place in fighting oil spills. They are ... yellow color, and filtered.

  5. Resuspension parameters for TRAC dispersion model

    International Nuclear Information System (INIS)

    Langer, G.

    1987-01-01

    Resuspension factors for the wind erosion of soil contaminated with plutonium are necessary to run the Rocky Flats Plant Terrain Responsive Atmospheric Code (TRAC). The model predicts the dispersion and resulting population dose due to accidental plutonium releases

  6. Modeling electrical dispersion phenomena in Earth materials

    Directory of Open Access Journals (Sweden)

    D. Patella

    2008-06-01

    Full Text Available It is illustrated that IP phenomena in rocks can be described using conductivity dispersion models deduced as solutions to a 2nd-order linear differential equation describing the motion of a charged particle immersed in an external electrical field. Five dispersion laws are discussed, namely: the non-resonant positive IP model, which leads to the classical Debye-type dispersion law and by extension to the Cole-Cole model, largely used in current practice; the non-resonant negative IP model, which allows negative chargeability values, known in metals at high frequencies, to be explained as an intrinsic physical property of earth materials in specific field cases; the resonant flat, positive or negative IP models, which can explain the presence of peak effects at specific frequencies superimposed on flat, positive or negative dispersion spectra.

  7. Long anterior zonules and pigment dispersion.

    Science.gov (United States)

    Moroi, Sayoko E; Lark, Kurt K; Sieving, Paul A; Nouri-Mahdavi, Kouros; Schlötzer-Schrehardt, Ursula; Katz, Gregory J; Ritch, Robert

    2003-12-01

    To describe pigment dispersion associated with long anterior zonules. Multicenter observational case series. Fifteen patients, seven of whom were treated for glaucoma or ocular hypertension, were identified with long anterior zonules and pigment dispersion. Transmission electron microscopy was performed on one anterior capsule specimen. All patients had anterior zonules that inserted centrally on the lens capsule. Signs of pigment dispersion included corneal endothelial pigmentation, loss of the pupillary ruff, and variable trabecular meshwork pigmentation. Ultrasound biomicroscopy verified the lack of posterior iris insertion and concavity. There was no exfoliation material. Transmission electron microscopy showed zonular lamellae with adherent pigment granules, and no exfoliation material. Long anterior zonules inserted onto the central lens capsule may cause mechanical disruption of the pigment epithelium at the pupillary ruff and central iris leading to pigment dispersion.

  8. Analytic properties of the whistler dispersion function

    International Nuclear Information System (INIS)

    Daniell, G.J.

    1986-01-01

    The analytic properties of the dispersion function of a whistler are investigated in the complex frequency plane. It possesses a pole and a branch point at a frequency equal to the minimum value of the electron gyrofrequency along the path of propagation. An integral equation relates the dispersion function to the distribution of magnetospheric electrons along the path and the solution of this equation is obtained. It is found that the electron density in the equatorial plane is very simply related to the dispersion function. A discussion of approximate formulae to represent the dispersion shows how particular terms can be related to attributes of the electron density distribution, and a new approximate formula is proposed. (author)

  9. Social Media Rhetoric of the Transnational Palestinian-led Boycott, Divestment, and Sanctions Movement

    Directory of Open Access Journals (Sweden)

    Jennifer Hitchcock

    2016-02-01

    Full Text Available This article uses rhetorical analysis to determine the effectiveness and characteristics of social media usage by the Boycott, Divestment, and Sanctions (BDS movement targeting Israel. Hundreds of local student, community, and religious groups in the United States use social media platforms such as Twitter and Facebook to promote BDS discourse and organize local BDS-related events. Even though social media platforms are important for an international movement composed of a very dispersed population, with millions of Palestinians also living under military occupation, the history of traditional media use during the First Intifada also suggests that social media are not necessary for mobilizing Palestinians at the local level. A preliminary rhetorical analysis of several BDS-related Facebook pages and Twitter accounts reveals that the BDS movement’s social media usage functions similarly in some ways to other contemporary mass movements by facilitating on-the-ground actions and delivering useful information to supporters. BDS movement social media discourse, however, does not establish the same level of emotional connection or interactivity with audiences as some other recent movements have, but these limitations can be partly explained by the unique political, material, and rhetorical constraints of the situation.

  10. SANS observations on weakly flocculated dispersions

    DEFF Research Database (Denmark)

    Mischenko, N.; Ourieva, G.; Mortensen, K.

    1997-01-01

    Structural changes occurring in colloidal dispersions of poly-(methyl metacrylate) (PMMA) particles, sterically stabilized with poly-(12-hydroxystearic acid) (PHSA), while varying the solvent quality, temperature and shear rate, are investigated by small-angle neutron scattering (SANS......). For a moderately concentrated dispersion in a marginal solvent the transition on cooling from the effective stability to a weak attraction is monitored, The degree of attraction is determined in the framework of the sticky spheres model (SSM), SANS and rheological results are correlated....

  11. Phonon dispersion relations for caesium thiocyanate

    International Nuclear Information System (INIS)

    Irving, M.A.; Smith, T.F.; Elcombe, M.M.

    1984-01-01

    Room temperature phonon dispersion relations for frequencies below 2 THz have been measured, along the three orthorhombic axes and selected diagonal directions by neutron inelastic scattering, for caesium thiocyanate. These curves, which represent 13 acoustic modes and 11 optic modes of vibration, do not agree with the dispersion behaviour calculated from the rigid-ion model developed by Ti and Ra to describe their Raman scattering observations

  12. Modelling of pollution dispersion in atmosphere

    International Nuclear Information System (INIS)

    Borysiewicz, M.; Stankiewicz, R.

    1994-01-01

    The paper contains the review of the mathematical foundation of atmospheric dispersion models. The atmospheric phenomena relevant to atmospheric dispersion model are discussed. In particular the parametrization of processes with time and space scales smaller than numerical grid size, limited by available computer power, is presented. The special attention was devoted to similarity theory and parametrization of boundary layer. The numerical methods are analysed and the drawbacks of the method are presented. (author). 99 refs, 15 figs, 3 tabs

  13. Employment Effects of Spatial Dispersal of Refugees

    DEFF Research Database (Denmark)

    Damm, Anna Piil; Rosholm, Michael

    Spatial dispersal policies may influence labour market integration of refugees through two mechanisms. First, it may affect the local job offer arrival rate, and second, it may affect place utility. We investigate the second mechanism theoretically by formulating a partial search model in which a...... due to large local reservation wage effects. We investigate both mechanisms empirically and test the predictions of the theoretical model by evaluating the employment effects of the Danish spatial dispersal policy carried out 1986-1998....

  14. Employment Effects of Spatial Dispersal of Refugees

    OpenAIRE

    Damm, Anna Piil; Rosholm, Michael

    2005-01-01

    We argue that spatial dispersal influences labour market assimilation of refugees through two mechanisms: first, the local job offer arrival rate and, second, place utility. Our partial search model with simultaneous job and residential location search predicts that the reservation wage for local jobs decreases with place utility. We argue that spatial dispersal decreases average place utility of refugees which decreases the transition rate into first job due to large local reservation wages....

  15. URANIUM BISMUTHIDE DISPERSION IN MOLTEN METAL

    Science.gov (United States)

    Teitel, R.J.

    1959-10-27

    The formation of intermetallic bismuth compounds of thorium or uranium dispersed in a liquid media containing bismuth and lead is described. A bismuthide of uranium dispersed in a liquid metal medium is formed by dissolving uranium in composition of lead and bismuth containing less than 80% lead and lowering the temperature of the composition to a temperature below the point at which the solubility of uranium is exceeded and above the melting point of the composition.

  16. The clinical approach to movement disorders.

    NARCIS (Netherlands)

    Abdo, W.F.; Warrenburg, B.P.C. van de; Burn, D.J.; Quinn, N.P.; Bloem, B.R.

    2010-01-01

    Movement disorders are commonly encountered in the clinic. In this Review, aimed at trainees and general neurologists, we provide a practical step-by-step approach to help clinicians in their 'pattern recognition' of movement disorders, as part of a process that ultimately leads to the diagnosis.

  17. Detecting movement patterns using Brownian bridges

    NARCIS (Netherlands)

    Buchin, K.; Sijben, S.; Arseneau, T.J.-M.; Willems, E.P.

    2012-01-01

    In trajectory data a low sampling rate leads to high uncertainty in between sampling points, which needs to be taken into account in the analysis of such data. However, current algorithms for movement analysis ignore this uncertainty and assume linear movement between sample points. In this paper we

  18. Towards a discursive analytics of movement

    DEFF Research Database (Denmark)

    Frello, Birgitta

    2008-01-01

    examples taken from Danish media, it is shown that the study of movement cannot be separated from that of discursive power. Access to and control over physical movement is unequally distributed. However, so is access to and control over assessing which activities can meaningfully be given the label...

  19. Rapid eye movement sleep behavior disorder

    DEFF Research Database (Denmark)

    Schenck, C H; Montplaisir, J Y; Frauscher, B

    2013-01-01

    We aimed to provide a consensus statement by the International Rapid Eye Movement Sleep Behavior Disorder Study Group (IRBD-SG) on devising controlled active treatment studies in rapid eye movement sleep behavior disorder (RBD) and devising studies of neuroprotection against Parkinson disease (PD...

  20. Movement initiation in groups of feral horses

    NARCIS (Netherlands)

    Krueger, Konstanze; Flauger, Birgit; Farmer, Kate; Hemelrijk, Charlotte

    Herds of ungulates, flocks of birds, swarms of insects and schools of fish move in coordinated groups. Computer models show that only one or very few animals are needed to initiate and direct movement. To investigate initiation mechanisms further, we studied two ways in which movement can be

  1. Orthodontic Tooth Movement: A Historic Prospective.

    Science.gov (United States)

    Will, Leslie A

    2016-01-01

    The earliest report on orthodontic tooth movement in the English literature was published in 1911. Oppenheim carried out studies on baboons to determine what histologic changes occurred during tooth movement. Reitan and many others carried out research into the nature of tooth movement. The pressure-tension model of tooth movement developed from these studies, whereby the two sides of the tooth responded to forces as if in isolation. A second theory, proposed by Stuteville in 1938, was the hydraulic theory of tooth movement. In this theory, fluid from the vasculature, lymphatic system and intercellular spaces responds to the forces of tooth movement, damping the force and limiting movement. Bien and Baumrind expanded on this theory with their own studies in the 1960s. It is clear that both the pressure-tension and fluid flow concepts have merit, but considerable work needs to be done to ascertain the details so that tooth movement can be managed and controlled. © 2016 S. Karger AG, Basel.

  2. ANALYSING SURFACE MOVEMENT DELAYS IN AN AIRPORT

    Directory of Open Access Journals (Sweden)

    Volodymyr Kharchenko

    2014-07-01

    Full Text Available Queuing effect can be in the different components of ground operations. Causes of surface – movement delays are long taxi – in and taxi – out operations during departure and arrival of aircraft. Surface movement delays in an airport are analyzed

  3. Historical Development of the Olympic Movement

    Directory of Open Access Journals (Sweden)

    Violeta Šiljak

    2017-10-01

    Full Text Available The Olympic Movement is a term that covers all areas related to the phenomenon of Olympism. From its creation, the Olympic Movement has had to follow and to respond to numerous challenges and changes of the 20th and 21st century. The successful work of the International Olympic Committee (IOC on the implementation of their projects related to world peace, the education of youth, equal inclusion of women in every aspect of the Movement, the establishment of the Women’s Commission, the Sport for All Commission, and the Sports and the Environment Commission are facts indicating that the IOC has a significant impact on the values of the Olympic Movement. In addition to equal participation of all athletes, today, the Olympic Movement provides Olympic solidarity, education and other programs. The basic method that was used in this study was the historical method, which includes heuristic, empirical and theoretical study of the origin and development of the IOC and its operation as part of the Olympic Movement. Research results indicate that the management of the IOCas a sporting organization that manages this Movement is directed at achieving the goal to contribute to building a more peaceful and better world by educating young people through sports, and in accordance with the Olympic values. With proper management, the IOChas improved sports and has grown into an organization that is at the head of the Olympic Movement.

  4. Active Movement Warm-Up Routines

    Science.gov (United States)

    Walter, Teri; Quint, Ashleigh; Fischer, Kim; Kiger, Joy

    2011-01-01

    This article presents warm-ups that are designed to physiologically and psychologically prepare students for vigorous physical activity. An active movement warm-up routine is made up of three parts: (1) active warm-up movement exercises, (2) general preparation, and (3) the energy system. These warm-up routines can be used with all grade levels…

  5. Fundamental Movement Skills and Autism Spectrum Disorders

    Science.gov (United States)

    Staples, Kerri L.; Reid, Greg

    2010-01-01

    Delays and deficits may both contribute to atypical development of movement skills by children with ASD. Fundamental movement skills of 25 children with autism spectrum disorders (ASD) (ages 9-12 years) were compared to three typically developing groups using the "Test of Gross Motor Development" ("TGMD-2"). The group matched on chronological age…

  6. Implementing Intervention Movement Programs for Kindergarten Children

    Science.gov (United States)

    Deli, Eleni; Bakle, Iliana; Zachopoulou, Evridiki

    2006-01-01

    The reported study aimed to identify the effects of two 10-week intervention programs on fundamental locomotor skill performance in kindergarten children. Seventy-five children with mean age 5.4 plus or minus 0.5 years participated. Experimental Group A followed a movement program, experimental Group B followed a music and movement program, and…

  7. Fundamental Movement Skill Proficiency amongst Adolescent Youth

    Science.gov (United States)

    O' Brien, Wesley; Belton, Sarahjane; Issartel, Johann

    2016-01-01

    Background: Literature suggests that physical education programmes ought to provide intense instruction towards basic movement skills needed to enjoy a variety of physical activities. Fundamental movement skills (FMS) are basic observable patterns of behaviour present from childhood to adulthood (e.g. run, skip and kick). Recent evidence indicates…

  8. Introduction: The Future of Social Movement Research

    NARCIS (Netherlands)

    Stekelenburg, Jacquelien Van; Roggeband, Conny; Stekelenburg, Jacquelien Van; Roggeband, Conny; Klandermans, Bert

    2013-01-01

    In The Future of Social Movement Research, some of the most influential scholars in the field provide a wide-ranging understanding of how social movements arise and persist, engendering unanswered questions pointing to new theoretical strands and fields of research. The resulting work is

  9. Using a developmental movement programme to enhance ...

    African Journals Online (AJOL)

    Brain research has shown that the brain is “plastic” in that it can adapt continuously, and its structure can be changed by certain kinds of stimulation, including movement. The body is a sensory-motor response system that causes the brain to organize itself. Movement is essential to learning and can be regarded as the door ...

  10. Social Movement Theory: Past, Present and Prospects

    NARCIS (Netherlands)

    van Stekelenburg, Jacquelien

    2009-01-01

    Mobilization against apartheid in South Africa, the campaign against blood diamonds, the women's movement in Liberia where Africa's first female head of State was elected in 2005 - these are all examples of socially based movements that have had a major effect on Africa's recent history. Yet the

  11. Movers and shakers : social movements in Africa

    NARCIS (Netherlands)

    Ellis, S.; Kessel, van W.M.J.

    2009-01-01

    Mobilization against apartheid in South Africa, the campaign against blood diamonds, the women's movement in Liberia where Africa's first female head of State was elected in 2005 - these are all examples of socially based movements that have had a major effect on Africa's recent history. Yet the

  12. Surgical management of movement disorders | Enslin | South ...

    African Journals Online (AJOL)

    Movement disorders are usually treated by neurologists, and appropriately so. The first-line management of all conditions that are grouped together as movement disorders (e.g. Parkinson's disease, dystonia, essential tremor) is with medication and, in some, with rehabilitative strategies, such as occupational therapy, ...

  13. The Ecology Movement after Ten Years.

    Science.gov (United States)

    Radcliffe, Betty; Gerlach, Luther P.

    1981-01-01

    Summarized are responses to a 1980 "Natural History""You and the Ecology Movement" questionnaire on ecological problems and the environmental movement. Returns indicate that concern for environmental quality is still very much in evidence, but some new directions and emphases are apparent. (WB)

  14. Mechanistic movement models to understand epidemic spread.

    Science.gov (United States)

    Fofana, Abdou Moutalab; Hurford, Amy

    2017-05-05

    An overlooked aspect of disease ecology is considering how and why animals come into contact with one and other resulting in disease transmission. Mathematical models of disease spread frequently assume mass-action transmission, justified by stating that susceptible and infectious hosts mix readily, and foregoing any detailed description of host movement. Numerous recent studies have recorded, analysed and modelled animal movement. These movement models describe how animals move with respect to resources, conspecifics and previous movement directions and have been used to understand the conditions for the occurrence and the spread of infectious diseases when hosts perform a type of movement. Here, we summarize the effect of the different types of movement on the threshold conditions for disease spread. We identify gaps in the literature and suggest several promising directions for future research. The mechanistic inclusion of movement in epidemic models may be beneficial for the following two reasons. Firstly, the estimation of the transmission coefficient in an epidemic model is possible because animal movement data can be used to estimate the rate of contacts between conspecifics. Secondly, unsuccessful transmission events, where a susceptible host contacts an infectious host but does not become infected can be quantified. Following an outbreak, this enables disease ecologists to identify 'near misses' and to explore possible alternative epidemic outcomes given shifts in ecological or immunological parameters.This article is part of the themed issue 'Opening the black box: re-examining the ecology and evolution of parasite transmission'. © 2017 The Author(s).

  15. Exploratory Visual Analysis for Animal Movement Ecology

    NARCIS (Netherlands)

    Slingsby, A.; van Loon, E.

    2016-01-01

    Movement ecologists study animals' movement to help understand their behaviours and interactions with each other and the environment. Data from GPS loggers are increasingly important for this. These data need to be processed, segmented and summarised for further visual and statistical analysis,

  16. Modelling and estimating pollen movement in oilseed rape (Brassica napus) at the landscape scale using genetic markers.

    Science.gov (United States)

    Devaux, C; Lavigne, C; Austerlitz, F; Klein, E K

    2007-02-01

    Understanding patterns of pollen movement at the landscape scale is important for establishing management rules following the release of genetically modified (GM) crops. We use here a mating model adapted to cultivated species to estimate dispersal kernels from the genotypes of the progenies of male-sterile plants positioned at different sampling sites within a 10 x 10-km oilseed rape production area. Half of the pollen clouds sampled by the male-sterile plants originated from uncharacterized pollen sources that could consist of both large volunteer and feral populations, and fields within and outside the study area. The geometric dispersal kernel was the most appropriate to predict pollen movement in the study area. It predicted a much larger proportion of long-distance pollination than previously fitted dispersal kernels. This best-fitting mating model underestimated the level of differentiation among pollen clouds but could predict its spatial structure. The estimation method was validated on simulated genotypic data, and proved to provide good estimates of both the shape of the dispersal kernel and the rate and composition of pollen issued from uncharacterized pollen sources. The best dispersal kernel fitted here, the geometric kernel, should now be integrated into models that aim at predicting gene flow at the landscape level, in particular between GM and non-GM crops.

  17. Dispersed-phase catalysis in coal liquefaction

    International Nuclear Information System (INIS)

    Utz, B.R.; Cugini, A.V.; Frommell, E.A.

    1990-01-01

    This paper reports that the specific reaction (activation) conditions for the conversion of catalyst precursors to unsupported catalyst have a direct effect on the catalytic activity and dispersion. The importance of reaction intermediates in decomposition of ammonium heptamolybdate and ammonium tetrathiomolybdate, and the sensitivity of these intermediates to reaction conditions, were studied in coal liquefaction systems. Recent results indicate that optimization of activation conditions facilitates the formation of a highly dispersed and active form of molybdenum disulfide for coal liquefaction. The use of the catalyst precursors ammonium heptamolybdate, ammonium tetrathiomolybdate, and molybdenum trisulfide for the conversion of coal to soluble products will be discussed. The use of an unsupported dispersed-phase catalyst for direct coal liquefaction is not a novel concept and has been employed in may studies with varying success. Dispersed-phase catalysts soluble and oil-soluble salts, and as finely divided powders. While some methods of catalyst introduction give higher dispersion of the catalyst and greater activity for the liquefaction of coal, all of the techniques allow the formation of a finely dispersed inorganic phase

  18. Estimate of dispersion in an unsaturated aquifer

    Science.gov (United States)

    Stephenson, D.; De Jesus, A. S. M.

    1985-10-01

    The Nuclear Development Corporation of South Africa (Pty) Ltd. (NUCOR) is constructing a low-level radioactive waste disposal site near Springbok in Namaqualand, an arid region to the west of South Africa. A groundwater model was developed which required site-specific data and this work describes procedures developed to assess the dispersivity of the soil in the vicinity of the proposed site. Preliminary laboratory tests, carried out using a sodium chloride solution, indicated the order of magnitude of the dispersivity for saturated soil at various levels. This enabled site tests to be designed. The site tests were done by injecting a pulse of scandium-46 into a hole and monitoring the displacement of the radioactive cloud as it moved down under gravity and spread laterally. A mathematical model was developed to predict the behaviour of the cloud and calibration of the model yielded vertical and horizontal dispersivities. The dispersion of radioactivity at the cloud front was assumed to occur in unsaturated medium while the continuously injected water behind the radioactivity was assumed to disperse in a saturated medium. Thus monitoring the concentration of both yielded approximate values for the effective dispersivities in unsaturated and saturated media.

  19. Spatially varying dispersion to model breakthrough curves.

    Science.gov (United States)

    Li, Guangquan

    2011-01-01

    Often the water flowing in a karst conduit is a combination of contaminated water entering at a sinkhole and cleaner water released from the limestone matrix. Transport processes in the conduit are controlled by advection, mixing (dilution and dispersion), and retention-release. In this article, a karst transport model considering advection, spatially varying dispersion, and dilution (from matrix seepage) is developed. Two approximate Green's functions are obtained using transformation of variables, respectively, for the initial-value problem and for the boundary-value problem. A numerical example illustrates that mixing associated with strong spatially varying conduit dispersion can cause strong skewness and long tailing in spring breakthrough curves. Comparison of the predicted breakthrough curve against that measured from a dye-tracing experiment between Ames Sink and Indian Spring, Northwest Florida, shows that the conduit dispersivity can be as large as 400 m. Such a large number is believed to imply strong solute interaction between the conduit and the matrix and/or multiple flow paths in a conduit network. It is concluded that Taylor dispersion is not dominant in transport in a karst conduit, and the complicated retention-release process between mobile- and immobile waters may be described by strong spatially varying conduit dispersion. Copyright © 2010 The Author(s). Journal compilation © 2010 National Ground Water Association.

  20. Magnon dispersion in thin magnetic films

    International Nuclear Information System (INIS)

    Balashov, T; Wulfhekel, W; Buczek, P; Sandratskii, L; Ernst, A

    2014-01-01

    Although the dispersion of magnons has been measured in many bulk materials, few studies deal with the changes in the dispersion when the material is in the form of a thin film, a system that is of interest for applications. Here we review inelastic tunneling spectroscopy studies of magnon dispersion in Mn/Cu 3 Au(1 0 0) and present new studies on Co and Ni thin films on Cu(1 0 0). The dispersion in Mn and Co films closely follows the dispersion of bulk samples with negligible dependence on thickness. The lifetime of magnons depends slightly on film thickness, and decreases considerably as the magnon energy increases. In Ni/Cu(1 0 0) films the thickness dependence of dispersion is much more pronounced. The measurements indicate a considerable mode softening for thinner films. Magnon lifetimes decrease dramatically near the edge of the Brillouin zone due to a close proximity of the Stoner continuum. The experimental study is supported by first-principles calculations. (paper)

  1. Magnon dispersion in thin magnetic films.

    Science.gov (United States)

    Balashov, T; Buczek, P; Sandratskii, L; Ernst, A; Wulfhekel, W

    2014-10-01

    Although the dispersion of magnons has been measured in many bulk materials, few studies deal with the changes in the dispersion when the material is in the form of a thin film, a system that is of interest for applications. Here we review inelastic tunneling spectroscopy studies of magnon dispersion in Mn/Cu3Au(1 0 0) and present new studies on Co and Ni thin films on Cu(1 0 0). The dispersion in Mn and Co films closely follows the dispersion of bulk samples with negligible dependence on thickness. The lifetime of magnons depends slightly on film thickness, and decreases considerably as the magnon energy increases. In Ni/Cu(1 0 0) films the thickness dependence of dispersion is much more pronounced. The measurements indicate a considerable mode softening for thinner films. Magnon lifetimes decrease dramatically near the edge of the Brillouin zone due to a close proximity of the Stoner continuum. The experimental study is supported by first-principles calculations.

  2. Surgical Management of Iatrogenic Pigment Dispersion Glaucoma.

    Science.gov (United States)

    Mierlo, Camille Van; Pinto, Luis Abegão; Stalmans, Ingeborg

    2015-01-01

    Iatrogenic pigment dispersion syndrome generally originates from a repetitive, mechanical trauma to the pigmented posterior epithelium of the iris. This trauma can arise after intraocular surgery, most commonly due to an abnormal contact between the intraocular lens (IOL) and the iris. Whether surgical removal of this primary insult can lead to a successful intraocular pressure (IOP) control remains unclear. Case-series. Patients with IOP elevation and clinical signs of pigment dispersion were screened for a diagnosis of iatrogenic IOL-related pigment dispersion. Three patients in which the IOL or the IOL-bag complex caused a pigment dispersion through a repetitive iris chafing were selected. In two cases, replacement of a sulcus-based single-piece IOL (patient 1) or a sub-luxated in-the-bag IOL (patient 2) by an anterior-chamber (AC) iris-fixed IOL led to a sustained decrease in IOP. In the third case, extensive iris atrophy and poor anatomical AC parameters for IOL implantation precluded further surgical intervention. IOL-exchange appears to be a useful tool in the management of iatrogenic pigment dispersion glaucoma due to inappropriate IOL implantation. This cause-oriented approach seems to be effective in controlling IOP, but should be offered only if safety criteria are met. How to cite this article: Van Mierlo C, Abegao Pinto L, Stalmans I. Surgical Management of Iatrogenic Pigment Dispersion Glaucoma. J Curr Glaucoma Pract 2015;9(1):28-32.

  3. Rheological Behavior of Bentonite-Polyester Dispersions

    Science.gov (United States)

    Abu-Jdayil, Basim; Al-Omari, Salah Addin

    2013-07-01

    The rheological behavior of a bentonite clay dispersed in unsaturated polyester was investigated. The effects of the solid content and particle size on the steady and transient rheological properties of the dispersions were studied. In addition, two types of bentonite with different Na+/Ca+2 ratio were used in this study. The Herschel-Bulkley and the Weltman models were used to describe the apparent viscosity of the bentonite-polyester composite in relation to the shear rate and shearing time. The bentonite-polyester dispersions were found to exhibit both Newtonian and non-Newtonian behavior. The transition from a Newtonian to a Bingham plastic and then to a shear-thinning material with a yield stress was found to depend on the solid concentration, the particle size, and the type of bentonite. At a low solid content, the apparent viscosity of the bentonite dispersion increased linearly with solid concentration. But a dramatic increase in the apparent viscosity beyond a solid content of 20 wt.% was observed. On the other hand, a thixotropic behavior was detected in bentonite-polyester dispersions with a high solid content and a low particle size. However, this behavior was more pronounced in dispersions with a high Na+/Ca+2 ratio.

  4. Effect of Canister Movement on Water Turbidity

    International Nuclear Information System (INIS)

    TRIMBLE, D.J.

    2000-01-01

    Requirements for evaluating the adherence characteristics of sludge on the fuel stored in the K East Basin and the effect of canister movement on basin water turbidity are documented in Briggs (1996). The results of the sludge adherence testing have been documented (Bergmann 1996). This report documents the results of the canister movement tests. The purpose of the canister movement tests was to characterize water turbidity under controlled canister movements (Briggs 1996). The tests were designed to evaluate methods for minimizing the plumes and controlling water turbidity during fuel movements leading to multi-canister overpack (MCO) loading. It was expected that the test data would provide qualitative visual information for use in the design of the fuel retrieval and water treatment systems. Video recordings of the tests were to be the only information collected

  5. Affective Body Movements (for Robots) Across Cultures

    DEFF Research Database (Denmark)

    Rehm, Matthias

    2018-01-01

    Humans are very good in expressing and interpreting emotions from a variety of different sources like voice, facial expression, or body movements. In this article, we concentrate on body movements and show that those are not only a source of affective information but might also have a different i...... with a study on creating an affective knocking movement for a humanoid robot and give details about a co-creation experiment for collecting a cross-cultural database on affective body movements and about the probabilistic model derived from this data....... interpretation in different cultures. To cope with these multiple viewpoints in generating and interpreting body movements in robots, we suggest a methodological approach that takes the cultural background of the developer and the user into account during the development process. We exemplify this approach...

  6. Movement Sonification: Audiovisual benefits on motor learning

    Directory of Open Access Journals (Sweden)

    Weber Andreas

    2011-12-01

    Full Text Available Processes of motor control and learning in sports as well as in motor rehabilitation are based on perceptual functions and emergent motor representations. Here a new method of movement sonification is described which is designed to tune in more comprehensively the auditory system into motor perception to enhance motor learning. Usually silent features of the cyclic movement pattern "indoor rowing" are sonified in real time to make them additionally available to the auditory system when executing the movement. Via real time sonification movement perception can be enhanced in terms of temporal precision and multi-channel integration. But beside the contribution of a single perceptual channel to motor perception and motor representation also mechanisms of multisensory integration can be addressed, if movement sonification is configured adequately: Multimodal motor representations consisting of at least visual, auditory and proprioceptive components - can be shaped subtly resulting in more precise motor control and enhanced motor learning.

  7. Attention modulates sensory suppression during back movements.

    Science.gov (United States)

    Van Hulle, Lore; Juravle, Georgiana; Spence, Charles; Crombez, Geert; Van Damme, Stefaan

    2013-06-01

    Tactile perception is often impaired during movement. The present study investigated whether such sensory suppression also occurs during back movements, and whether this would be modulated by attention. In two tactile detection experiments, participants simultaneously engaged in a movement task, in which they executed a back-bending movement, and a perceptual task, consisting of the detection of subtle tactile stimuli administered to their upper or lower back. The focus of participants' attention was manipulated by raising the probability that one of the back locations would be stimulated. The results revealed that tactile detection was suppressed during the execution of the back movements. Furthermore, the results of Experiment 2 revealed that when the stimulus was always presented to the attended location, tactile suppression was substantially reduced, suggesting that sensory suppression can be modulated by top-down attentional processes. The potential of this paradigm for studying tactile information processing in clinical populations is discussed. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Study of Movement Speeds Down Stairs

    CERN Document Server

    Hoskins, Bryan L

    2013-01-01

    The Study of Movement Speeds Down Stairs closely examines forty-three unique case studies on movement patterns down stairwells. These studies include observations made during evacuation drills, others made during normal usage, interviews with people after fire evacuations, recommendations made from compiled studies, and detailed results from laboratory studies. The methodology used in each study for calculating density and movement speed, when known, are also presented, and this book identifies an additional seventeen variables linked to altering movement speeds. The Study of Movement Speeds Down Stairs is intended for researchers as a reference guide for evaluating pedestrian evacuation dynamics down stairwells. Practitioners working in a related field may also find this book invaluable.

  9. Cefuroxime axetil solid dispersions prepared using solution enhanced dispersion by supercritical fluids.

    Science.gov (United States)

    Jun, Seoung Wook; Kim, Min-Soo; Jo, Guk Hyun; Lee, Sibeum; Woo, Jong Soo; Park, Jeong-Sook; Hwang, Sung-Joo

    2005-12-01

    Cefuroxime axetil (CA) solid dispersions with HPMC 2910/PVP K-30 were prepared using solution enhanced dispersion by supercritical fluids (SEDS) in an effort to increase the dissolution rate of poorly water-soluble drugs. Their physicochemical properties in solid state were characterized by differential scanning calorimeter (DSC), powder X-ray diffraction (PXRD), Fourier transform infrared spectrometry (FT-IR) and scanning electron microscopy. No endothermic and characteristic diffraction peaks corresponding to CA were observed for the solid dispersions in DSC and PXRD. FTIR analysis demonstrated the presence of intermolecular hydrogen bonds between CA and HPMC 2910/PVP K-30 in solid dispersions, resulting in the formation of amorphous or non-crystalline CA. Dissolution studies indicated that the dissolution rates were remarkably increased in solid dispersions compared with those in the physical mixture and drug alone. In conclusion, an amorphous or non-crystalline CA solid dispersion prepared using SEDS could be very useful for the formulation of solid dosage forms.

  10. Dispersal kernel estimation: A comparison of empirical and modelled particle dispersion in a coastal marine system

    Science.gov (United States)

    Hrycik, Janelle M.; Chassé, Joël; Ruddick, Barry R.; Taggart, Christopher T.

    2013-11-01

    Early life-stage dispersal influences recruitment and is of significance in explaining the distribution and connectivity of marine species. Motivations for quantifying dispersal range from biodiversity conservation to the design of marine reserves and the mitigation of species invasions. Here we compare estimates of real particle dispersion in a coastal marine environment with similar estimates provided by hydrodynamic modelling. We do so by using a system of magnetically attractive particles (MAPs) and a magnetic-collector array that provides measures of Lagrangian dispersion based on the time-integration of MAPs dispersing through the array. MAPs released as a point source in a coastal marine location dispersed through the collector array over a 5-7 d period. A virtual release and observed (real-time) environmental conditions were used in a high-resolution three-dimensional hydrodynamic model to estimate the dispersal of virtual particles (VPs). The number of MAPs captured throughout the collector array and the number of VPs that passed through each corresponding model location were enumerated and compared. Although VP dispersal reflected several aspects of the observed MAP dispersal, the comparisons demonstrated model sensitivity to the small-scale (random-walk) particle diffusivity parameter (Kp). The one-dimensional dispersal kernel for the MAPs had an e-folding scale estimate in the range of 5.19-11.44 km, while those from the model simulations were comparable at 1.89-6.52 km, and also demonstrated sensitivity to Kp. Variations among comparisons are related to the value of Kp used in modelling and are postulated to be related to MAP losses from the water column and (or) shear dispersion acting on the MAPs; a process that is constrained in the model. Our demonstration indicates a promising new way of 1) quantitatively and empirically estimating the dispersal kernel in aquatic systems, and 2) quantitatively assessing and (or) improving regional hydrodynamic

  11. Effects of Land Cover on the Movement of Frugivorous Birds in a Heterogeneous Landscape.

    Science.gov (United States)

    Da Silveira, Natalia Stefanini; Niebuhr, Bernardo Brandão S; Muylaert, Renata de Lara; Ribeiro, Milton Cezar; Pizo, Marco Aurélio

    2016-01-01

    Movement is a key spatiotemporal process that enables interactions between animals and other elements of nature. The understanding of animal trajectories and the mechanisms that influence them at the landscape level can yield insight into ecological processes and potential solutions to specific ecological problems. Based upon optimal foraging models and empirical evidence, we hypothesized that movement by thrushes is highly tortuous (low average movement speeds and homogeneous distribution of turning angles) inside forests, moderately tortuous in urban areas, which present intermediary levels of resources, and minimally tortuous (high movement speeds and turning angles next to 0 radians) in open matrix types (e.g., crops and pasture). We used data on the trajectories of two common thrush species (Turdus rufiventris and Turdus leucomelas) collected by radio telemetry in a fragmented region in Brazil. Using a maximum likelihood model selection approach we fit four probability distribution models to average speed data, considering short-tailed, long-tailed, and scale-free distributions (to represent different regimes of movement variation), and one distribution to relative angle data. Models included land cover type and distance from forest-matrix edges as explanatory variables. Speed was greater farther away from forest edges and increased faster inside forest habitat compared to urban and open matrices. However, turning angle was not influenced by land cover. Thrushes presented a very tortuous trajectory, with many displacements followed by turns near 180 degrees. Thrush trajectories resembled habitat and edge dependent, tortuous random walks, with a well-defined movement scale inside each land cover type. Although thrushes are habitat generalists, they showed a greater preference for forest edges, and thus may be considered edge specialists. Our results reinforce the importance of studying animal movement patterns in order to understand ecological processes such as

  12. Dissociable contribution of the parietal and frontal cortex to coding movement direction and amplitude

    Directory of Open Access Journals (Sweden)

    Marco eDavare

    2015-05-01

    Full Text Available To reach for an object, we must convert its spatial location into an appropriate motor command, merging movement direction and amplitude. In humans, it has been suggested that this visuo-motor transformation occurs in a dorsomedial parieto-frontal pathway, although the causal contribution of the areas constituting the reaching circuit remains unknown. Here we used transcranial magnetic stimulation (TMS in healthy volunteers to disrupt the function of either the medial intraparietal area (mIPS or dorsal premotor cortex (PMd, in each hemisphere. The task consisted in performing step-tracking movements with the right wrist towards targets located in different directions and eccentricities; the targets were either visible for the whole trial (Target-ON or flashed for 200 ms (Target-OFF. Left and right mIPS disruption led to errors in the initial direction of movements performed towards contralateral targets. These errors were corrected online in the Target-ON condition but when the target was flashed for 200 ms, mIPS TMS manifested as a larger endpoint spreading. In contrast, left PMd virtual lesions led to higher acceleration and velocity peaks - two parameters typically used to probe the planned movement amplitude - irrespective of the target position, hemifield and presentation condition; in the Target-OFF condition, left PMd TMS induced overshooting and increased the endpoint dispersion along the axis of the target direction. These results indicate that left PMd intervenes in coding amplitude during movement preparation. The critical TMS timings leading to errors in direction and amplitude were different, namely 160-100 ms before movement onset for mIPS and 100-40 ms for left PMd. TMS applied over right PMd had no significant effect. These results indicate that, during motor preparation, direction and amplitude of goal-directed movements are processed by different cortical areas, at distinct timings, and according to a specific hemispheric

  13. Effects of Land Cover on the Movement of Frugivorous Birds in a Heterogeneous Landscape.

    Directory of Open Access Journals (Sweden)

    Natalia Stefanini Da Silveira

    Full Text Available Movement is a key spatiotemporal process that enables interactions between animals and other elements of nature. The understanding of animal trajectories and the mechanisms that influence them at the landscape level can yield insight into ecological processes and potential solutions to specific ecological problems. Based upon optimal foraging models and empirical evidence, we hypothesized that movement by thrushes is highly tortuous (low average movement speeds and homogeneous distribution of turning angles inside forests, moderately tortuous in urban areas, which present intermediary levels of resources, and minimally tortuous (high movement speeds and turning angles next to 0 radians in open matrix types (e.g., crops and pasture. We used data on the trajectories of two common thrush species (Turdus rufiventris and Turdus leucomelas collected by radio telemetry in a fragmented region in Brazil. Using a maximum likelihood model selection approach we fit four probability distribution models to average speed data, considering short-tailed, long-tailed, and scale-free distributions (to represent different regimes of movement variation, and one distribution to relative angle data. Models included land cover type and distance from forest-matrix edges as explanatory variables. Speed was greater farther away from forest edges and increased faster inside forest habitat compared to urban and open matrices. However, turning angle was not influenced by land cover. Thrushes presented a very tortuous trajectory, with many displacements followed by turns near 180 degrees. Thrush trajectories resembled habitat and edge dependent, tortuous random walks, with a well-defined movement scale inside each land cover type. Although thrushes are habitat generalists, they showed a greater preference for forest edges, and thus may be considered edge specialists. Our results reinforce the importance of studying animal movement patterns in order to understand ecological

  14. Integrating animal movement with habitat suitability for estimating dynamic landscape connectivity

    Science.gov (United States)

    van Toor, Mariëlle L.; Kranstauber, Bart; Newman, Scott H.; Prosser, Diann J.; Takekawa, John Y.; Technitis, Georgios; Weibel, Robert; Wikelski, Martin; Safi, Kamran

    2018-01-01

    Context High-resolution animal movement data are becoming increasingly available, yet having a multitude of empirical trajectories alone does not allow us to easily predict animal movement. To answer ecological and evolutionary questions at a population level, quantitative estimates of a species’ potential to link patches or populations are of importance. Objectives We introduce an approach that combines movement-informed simulated trajectories with an environment-informed estimate of the trajectories’ plausibility to derive connectivity. Using the example of bar-headed geese we estimated migratory connectivity at a landscape level throughout the annual cycle in their native range. Methods We used tracking data of bar-headed geese to develop a multi-state movement model and to estimate temporally explicit habitat suitability within the species’ range. We simulated migratory movements between range fragments, and calculated a measure we called route viability. The results are compared to expectations derived from published literature. Results Simulated migrations matched empirical trajectories in key characteristics such as stopover duration. The viability of the simulated trajectories was similar to that of the empirical trajectories. We found that, overall, the migratory connectivity was higher within the breeding than in wintering areas, corroborating previous findings for this species. Conclusions We show how empirical tracking data and environmental information can be fused for meaningful predictions of animal movements throughout the year and even outside the spatial range of the available data. Beyond predicting migratory connectivity, our framework will prove useful for modelling ecological processes facilitated by animal movement, such as seed dispersal or disease ecology.

  15. Design and development of a dust dispersion chamber to quantify the dispersibility of rock dust.

    Science.gov (United States)

    Perera, Inoka E; Sapko, Michael J; Harris, Marcia L; Zlochower, Isaac A; Weiss, Eric S

    2016-01-01

    Dispersible rock dust must be applied to the surfaces of entries in underground coal mines in order to inert the coal dust entrained or made airborne during an explosion and prevent propagating explosions. 30 CFR. 75.2 states that "… [rock dust particles] when wetted and dried will not cohere to form a cake which will not be dispersed into separate particles by a light blast of air …" However, a proper definition or quantification of "light blast of air" is not provided. The National Institute for Occupational Safety and Health (NIOSH) has, consequently, designed a dust dispersion chamber to conduct quantitative laboratory-scale dispersibility experiments as a screening tool for candidate rock dusts. A reproducible pulse of air is injected into the chamber and across a shallow tray of rock dust. The dust dispersed and carried downwind is monitored. The mass loss of the dust tray and the airborne dust measurements determine the relative dispersibility of the dust with respect to a Reference rock dust. This report describes the design and the methodology to evaluate the relative dispersibility of rock dusts with and without anti-caking agents. Further, the results of this study indicate that the dispersibility of rock dusts varies with particle size, type of anti-caking agent used, and with the untapped bulk density. Untreated rock dusts, when wetted and dried forming a cake that was much less dispersible than the reference rock dust used in supporting the 80% total incombustible content rule.

  16. The dispersion of SWCNTs treated by coupling and dispersing agents in fiber reinforced polymer composities

    Science.gov (United States)

    Duan, Yuexin; Yuan, Lu; Zhao, Yan; Guan, Fengxia

    2007-07-01

    It is an obstacle issue for Carbon nanotubes (CNTs) applied in fiber reinforced polymer composites that CNTs is dispersed in nano-level, particularly for single-wall Carbon nanotubes (SWCNTs). In this paper, SWCNTs were treated by the coupling agent like volan and dispersing agent as BYK to improve the dispersion in the Glass Fiber/Epoxy composites. The result of dispersion of SWCNTs in composites was observed by Scanning electron microscopy (SEM). Then the Glass Transition Temperature (Tg) of these kinds of composites with treated and untreated SWCNTs were obtained by Dynamic Mechanical Thermal Analysis (DMTA). Moreover, the bending properties of these composites were tested.

  17. Current Migration Movements in Europe

    Directory of Open Access Journals (Sweden)

    Jelena Zlatković Winter

    2004-09-01

    Full Text Available After a brief historical review of migrations in Europe, the paper focuses on current migration trends and their consequences. At the end of the 1950s, Western Europe began to recruit labour from several Mediterranean countries – Italy, Spain, Portugal and former Yugoslavia, and later from Morocco, Algeria, Tunisia and Turkey. Some countries, such as France, Great Britain and the Netherlands, recruited also workers from their former colonies. In 1970 Germany had the highest absolute number of foreigners, followed by France, and then Switzerland and Belgium. The total number of immigrants in Western Europe was twelve million. During the 1970s mass recruitment of foreign workers was abandoned, and only the arrival of their family members was permitted, which led to family reunification in the countries of employment. Europe closed its borders, with the result that clandestine migration increased. The year 1989 was a turning point in the history of international migrations. The political changes in Central and Eastern Europe brought about mass migration to the West, which culminated in the so-called “mass movement of 1989–1990”. The arrival of ethnic Germans in Germany, migration inside and outside of the territory of the former Soviet Union, an increase in the number of asylum seekers and displaced persons, due to armed conflicts, are – according to the author – the main traits of current migration. The main part of the paper discusses the causes and effects of this mass wave, as well as trends in labour migration, which is still present. The second part of the paper, after presenting a typology of migrations, deals with the complex processes that brought about the formation of new communities and led to the phenomenon of new ethnic minorities and to corresponding migration policies in Western European countries that had to address these issues.

  18. Meteorology and dispersion forecast in nuclear emergency in Argentina

    International Nuclear Information System (INIS)

    Kunst, Juan J.; Boutet, Luis I.; Jordan, Osvaldo D.; Hernandez, Daniel G.; Guichandut, M.E.; Chiappesoni, H.

    2008-01-01

    The 'Nuclear Regulatory Authority (NRA) (ARN in Spanish)' and the 'National Meteorological Office (NMO) (SMN in Spanish)' of Argentine has been working together on the improvement of both meteorological forecasting and dispersion prediction. In the pre-release phase of a nuclear emergency, it is very important to know the wind direction and the forecast of it, to establish the area, around the installation, where the emergency state is declared and to foresee the modification of this area. Information is also needed about deterministic effects, to begin the evacuation. At this time, meteorological forecast of wind direction and speed, and the real time meteorological information is available in the nuclear power plant (NPP) and in the Nuclear Emergency Control Centre at the ARN headquarters, together with the short-range dose calculation provided by our dispersion code, SEDA. By means of the SEDA code, we can estimate the optimum place to measure the radioactive material concentration in air, needed do to reduce evaluation uncertainties due, among others, to poor knowledge of the source term. The SEDA code allows considering atmospheric condition, and the need to reduced doses of the measuring team in charge of the measurements. For the evaluation in the medium range, we participate in the project IXP, which provides four hours and about 50 kilometres forecast. In the long-range movement of air borne radioactivity, the World Meteorological Organization (WMO), whose contact point in Argentina is the SMN, can assist us. We have developed together, with the SMN, a detailed procedure to request assistance from the WMO. In this work, we describe the combined tasks that were carried out with the SMN to define the procedures and the concepts for their application during a real emergency. The results of an application exercise carried out in 2006 are also described. (author)

  19. Movement recognition technology as a method of assessing spontaneous general movements in high risk infants

    Directory of Open Access Journals (Sweden)

    Claire eMarcroft

    2015-01-01

    Full Text Available Preterm birth is associated with increased risks of neurological and motor impairments such as cerebral palsy. The risks are highest in those born at the lowest gestations. Early identification of those most at risk is challenging meaning that a critical window of opportunity to improve outcomes through therapy-based interventions may be missed. Clinically, the assessment of spontaneous general movements is an important tool which can be used for the prediction of movement impairments in high risk infants.Movement recognition aims to capture and analyze relevant limb movements through computerized approaches focusing on continuous, objective, and quantitative assessment. Different methods of recording and analyzing infant movements have recently been explored in high risk infants. These range from camera-based solutions to body-worn miniaturized movement sensors used to record continuous time-series data that represent the dynamics of limb movements. Various machine learning methods have been developed and applied to the analysis of the recorded movement data. This analysis has focused on the detection and classification of atypical spontaneous general movements. This paper aims to identify recent translational studies using movement recognition technology as a method of assessing movement in high risk infants. The application of this technology within pediatric practice represents a growing area of inter-disciplinary collaboration which may lead to a greater understanding of the development of the nervous system in infants at high risk of motor impairment.

  20. A Somatic Movement Approach to Fostering Emotional Resiliency through Laban Movement Analysis

    Directory of Open Access Journals (Sweden)

    Rachelle P. Tsachor

    2017-09-01

    Full Text Available Although movement has long been recognized as expressing emotion and as an agent of change for emotional state, there was a dearth of scientific evidence specifying which aspects of movement influence specific emotions. The recent identification of clusters of Laban movement components which elicit and enhance the basic emotions of anger, fear, sadness and happiness indicates which types of movements can affect these emotions (Shafir et al., 2016, but not how best to apply this knowledge. This perspective paper lays out a conceptual groundwork for how to effectively use these new findings to support emotional resiliency through voluntary choice of one's posture and movements. We suggest that three theoretical principles from Laban Movement Analysis (LMA can guide the gradual change in movement components in one's daily movements to somatically support shift in affective state: (A Introduce new movement components in developmental order; (B Use LMA affinities-among-components to guide the expansion of expressive movement range and (C Sequence change among components based on Laban's Space Harmony theory to support the gradual integration of that new range. The methods postulated in this article have potential to foster resiliency and provide resources for self-efficacy by expanding our capacity to adapt emotionally to challenges through modulating our movement responses.