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Sample records for long-distance pollen flow

  1. LONG DISTANCE POLLEN-MEDIATED GENE FLOW FROM CREEPING BENTGRASS

    Science.gov (United States)

    Researchers from USEPA WED have measured gene flow from experimental fields of Roundup? herbicide resistant genetically modified (GM) creeping bentgrass a grass used primarily on golf courses, to compatible non-crop relatives. Using a sampling design based on the estimated time ...

  2. Long distance pollen-mediated flow of herbicide resistance genes in Lolium rigidum.

    Science.gov (United States)

    Busi, Roberto; Yu, Qin; Barrett-Lennard, Robert; Powles, Stephen

    2008-11-01

    Gene flow promotes genetic exchange among plant populations mediating evolutionary dynamics; yet, the importance of gene flow at distance via pollen movement is poorly understood. A field experiment at the landscape level was conducted with Lolium rigidum herbicide-susceptible individuals (population VLR1) placed into an otherwise Lolium-free bushland environment at increasing distances from adjacent large commercial crop fields infested with herbicide-resistant L. rigidum. Herbicide resistance was used as a marker to quantify the distance and the rate of pollen-mediated gene flow. About 21,245 seeds were produced on the isolated, susceptible mother plants of which 3,303 seedlings were tested for herbicide resistance and 664 seedlings were found to be resistant. Pollen-mediated gene flow occurred at 3,000 m (maximum tested distance). Both Mendelian and molecular analyses (sequencing and CAPS markers) confirmed the introgression of herbicide resistance genes. This is the first documented case of long-distance gene flow in L. rigidum. The results are important for future modeling simulations of herbicide resistance evolution and subsequent mobility. The adoption of integrated agronomic strategies, the control of potential receptor plants on fields' margins and conservative use of herbicides can be realistic options to minimize herbicide resistance spread.

  3. Long distance pollen-mediated gene flow at a landscape level: the weed beet as a case study.

    Science.gov (United States)

    Fénart, Stéphane; Austerlitz, Frédéric; Cuguen, Joël; Arnaud, Jean-François

    2007-09-01

    Gene flow is a crucial parameter that can affect the organization of genetic diversity in plant species. It has important implications in terms of conservation of genetic resources and of gene exchanges between crop to wild relatives and within crop species complex. In the Beta vulgaris complex, hybridization between crop and wild beets in seed production areas is well documented and the role of the ensuing hybrids, weed beets, as bridges towards wild forms in sugar beet production areas have been shown. Indeed, in contrast to cultivated beets that are bi-annual, weed beets can bolt, flower and reproduce in the same crop season. Nonetheless, the extent of pollen gene dispersal through weedy lineages remains unknown. In this study, the focus is directed towards weed-to-weed gene flow, and we report the results of a pollen-dispersal analysis within an agricultural landscape composed of five sugar beet fields with different levels of infestation by weed beets. Our results, based on paternity analysis of 3240 progenies from 135 maternal plants using 10 microsatellite loci, clearly demonstrate that even if weedy plants are mostly pollinated by individuals from the same field, some mating events occur between weed beets situated several kilometres apart (up to 9.6 km), with rates of interfield-detected paternities ranging from 11.3% to 17.5%. Moreover, we show that pollen flow appears to be more restricted when individuals are aggregated as most mating events occurred only for short-distance classes. The best-fit dispersal curves were fat-tailed geometric functions for populations exhibiting low densities of weed beets and thin-tailed Weibull function for fields with weed beet high densities. Thus, weed beet populations characterized by low density with geographically isolated individuals may be difficult to detect but are likely to act as pollen traps for pollen emitted by close and remote fields. Hence, it appears evident that interfield pollen-mediated gene flow

  4. Effective long-distance pollen dispersal in Centaurea jacea.

    Directory of Open Access Journals (Sweden)

    Matthias Albrecht

    Full Text Available BACKGROUND: Agri-environment schemes play an increasingly important role for the conservation of rare plants in intensively managed agricultural landscapes. However, little is known about their effects on gene flow via pollen dispersal between populations of these species. METHODOLOGY/PRINCIPAL FINDINGS: In a 2-year experiment, we observed effective pollen dispersal from source populations of Centaurea jacea in restored meadows, the most widespread Swiss agri-environment scheme, to potted plants in adjacent intensively managed meadows without other individuals of this species. Potted plants were put in replicated source populations at 25, 50, 100 m and where possible 200 m distance from these source populations. Pollen transfer among isolated plants was prevented by temporary bagging, such that only one isolated plant was accessible for flower visitors at any one time. Because C. jacea is self-incompatible, seed set in single-plant isolates indicated insect mediated effective pollen dispersal from the source population. Seed set was higher in source populations (35.7+/-4.4 than in isolates (4.8+/-1.0. Seed set declined from 18.9% of that in source populations at a distance of 25 m to 7.4% at 200 m. At a distance of 200 m seed set was still significantly higher in selfed plants, indicating long-distance effective pollen dispersal up to 200 m. Analyses of covariance suggested that bees contributed more than flies to this long-distance pollen dispersal. We found evidence that pollen dispersal to single-plant isolates was positively affected by the diversity and flower abundance of neighboring plant species in the intensively managed meadow. Furthermore, the decline of the dispersal was less steep when the source population of C. jacea was large. CONCLUSIONS: We conclude that insect pollinators can effectively transfer pollen from source populations of C. jacea over at least 200 m, even when "recipient populations" consisted of single-plant isolates

  5. Influence of long-distance seed dispersal on the genetic diversity of seed rain in fragmented Pinus densiflora populations relative to pollen-mediated gene flow.

    Science.gov (United States)

    Ozawa, Hajime; Watanabe, Atsushi; Uchiyama, Kentaro; Saito, Yoko; Ide, Yuji

    2013-01-01

    Long-distance dispersal (LDD) of seeds has a critical impact on species survival in patchy landscapes. However, relative to pollen dispersal, empirical data on how seed LDD affects genetic diversity in fragmented populations have been poorly reported. Thus, we attempted to indirectly evaluate the influence of seed LDD by estimating maternal and paternal inbreeding in the seed rain of fragmented 8 Pinus densiflora populations. In total, the sample size was 458 seeds and 306 adult trees. Inbreeding was estimated by common parentage analysis to evaluate gene flow within populations and by sibship reconstruction analysis to estimate gene flow within and among populations. In the parentage analysis, the observed probability that sampled seeds had the same parents within populations was significantly larger than the expected probability in many populations. This result suggested that gene dispersal was limited to within populations. In the sibship reconstruction, many donors both within and among populations appeared to contribute to sampled seeds. Significant differences in sibling ratios were not detected between paternity and maternity. These results suggested that seed-mediated gene flow and pollen-mediated gene flow from outside population contributed some extent to high genetic diversity of the seed rain (H E > 0.854). We emphasize that pine seeds may have excellent potential for gene exchange within and among populations.

  6. Effective Long-Distance Pollen Dispersal in Centaurea jacea

    OpenAIRE

    Albrecht, M; Duelli, P; M. K. Obrist; Müller, C.; Kleijn, D.; Schmid, B.

    2009-01-01

    Background Agri-environment schemes play an increasingly important role for the conservation of rare plants in intensively managed agricultural landscapes. However, little is known about their effects on gene flow via pollen dispersal between populations of these species. Methodology/Principal Findings In a 2-year experiment, we observed effective pollen dispersal from source populations of Centaurea jacea in restored meadows, the most widespread Swiss agri-environment scheme, to potted plant...

  7. Effective Long-Distance Pollen Dispersal in Centaurea jacea

    OpenAIRE

    Matthias Albrecht; Peter Duelli; Obrist, Martin K.; David Kleijn; Bernhard Schmid

    2009-01-01

    BACKGROUND: Agri-environment schemes play an increasingly important role for the conservation of rare plants in intensively managed agricultural landscapes. However, little is known about their effects on gene flow via pollen dispersal between populations of these species. METHODOLOGY/PRINCIPAL FINDINGS: In a 2-year experiment, we observed effective pollen dispersal from source populations of Centaurea jacea in restored meadows, the most widespread Swiss agri-environment scheme, to potted pla...

  8. Effective Long-Distance Pollen Dispersal in Centaurea jacea

    NARCIS (Netherlands)

    Albrecht, M.; Duelli, P.; Obrist, M.K.; Müller, C.; Kleijn, D.; Schmid, B.

    2009-01-01

    Background Agri-environment schemes play an increasingly important role for the conservation of rare plants in intensively managed agricultural landscapes. However, little is known about their effects on gene flow via pollen dispersal between populations of these species. Methodology/Principal Findi

  9. Molecular analysis confirms the long-distance transport of Juniperus ashei pollen.

    Science.gov (United States)

    Mohanty, Rashmi Prava; Buchheim, Mark Alan; Anderson, James; Levetin, Estelle

    2017-01-01

    Although considered rare, airborne pollen can be deposited far from its place of origin under a confluence of favorable conditions. Temporally anomalous records of Cupressacean pollen collected from January air samples in London, Ontario, Canada have been cited as a new case of long-distance transport. Data on pollination season implicated Juniperus ashei (mountain cedar), with populations in central Texas and south central Oklahoma, as the nearest source of the Cupressacean pollen in the Canadian air samples. This finding is of special significance given the allergenicity of mountain cedar pollen. While microscopy is used extensively to identify particles in the air spora, pollen from all members of the Cupressaceae, including Juniperus, are morphologically indistinguishable. Consequently, we implemented a molecular approach to characterize Juniperus pollen using PCR in order to test the long-distance transport hypothesis. Our PCR results using species-specific primers confirmed that the anomalous Cupressacean pollen collected in Canada was from J. ashei. Forward trajectory analysis from source areas in Texas and the Arbuckle Mountains in Oklahoma and backward trajectory analysis from the destination area near London, Ontario were completed using models implemented in HYSPLIT4 (Hybrid Single-Particle Lagrangian Integrated Trajectory). Results from these trajectory analyses strongly supported the conclusion that the J. ashei pollen detected in Canada had its origins in Texas or Oklahoma. The results from the molecular findings are significant as they provide a new method to confirm the long-distance transport of pollen that bears allergenic importance.

  10. Heterosis may result in selection favouring the products of long-distance pollen dispersal in Eucalyptus.

    Directory of Open Access Journals (Sweden)

    João Costa E Silva

    Full Text Available Using native trees from near the northern and southern extremities of the relatively continuous eastern distribution of Eucalyptus globulus in Tasmania, we compared the progenies derived from natural open-pollination (OP with those generated from within-region and long-distance outcrossing. Controlled outcrossing amongst eight parents - with four parents from each of the northern and southern regions - was undertaken using a diallel mating scheme. The progeny were planted in two field trials located within the species native range in southern Tasmania, and their survival and diameter growth were monitored over a 13-year-period. The survival and growth performances of all controlled cross types exceeded those of the OP progenies, consistent with inbreeding depression due to a combination of selfing and bi-parental inbreeding. The poorer survival of the northern regional (♀N♂N outcrosses compared with the local southern regional outcrosses (♀S♂S indicated differential selection against the former. Despite this mal-adaptation of the non-local ♀N♂N crosses at both southern sites, the survival of the inter-regional hybrids (♀N♂S and ♀S♂N was never significantly different from that of the local ♀S♂S crosses. Significant site-dependent heterosis was detected for the growth of the surviving long-distance hybrids. This was expressed as mid-parent heterosis, particularly at the more northern planting site. Heterosis increased with age, while the difference between the regional ♀N♂N and ♀S♂S crosses remained insignificant at any age at either site. Nevertheless, the results for growth suggest that the fitness of individuals derived from long-distance crossing may be better at the more northern of the planting sites. Our results demonstrate the potential for early-age assessments of pollen dispersal to underestimate realised gene flow, with local inbreeding under natural open-pollination resulting in selection favouring the

  11. Euglossine bees mediate only limited long-distance gene flow in a tropical vine.

    Science.gov (United States)

    Opedal, Øystein H; Falahati-Anbaran, Mohsen; Albertsen, Elena; Armbruster, W Scott; Pérez-Barrales, Rocío; Stenøien, Hans K; Pélabon, Christophe

    2017-03-01

    Euglossine bees (Apidae: Euglossini) have long been hypothesized to act as long-distance pollinators of many low-density tropical plants. We tested this hypothesis by the analysis of gene flow and genetic structure within and among populations of the euglossine bee-pollinated vine Dalechampia scandens. Using microsatellite markers, we assessed historical gene flow by the quantification of regional-scale genetic structure and isolation by distance among 18 populations, and contemporary gene flow by the estimation of recent migration rates among populations. To assess bee-mediated pollen dispersal on a smaller scale, we conducted paternity analyses within a focal population, and quantified within-population spatial genetic structure in four populations. Gene flow was limited to certain nearby populations within continuous forest blocks, whereas drift appeared to dominate on larger scales. Limited long-distance gene flow was supported by within-population patterns; gene flow was biased towards nearby plants, and significant small-scale spatial genetic structure was detected within populations. These findings suggest that, although female euglossine bees might be effective at moving pollen within populations, and perhaps within forest blocks, their contribution to gene flow on the regional scale seems too limited to counteract genetic drift in patchily distributed tropical plants. Among-population gene flow might have been reduced following habitat fragmentation.

  12. Native bees mediate long-distance pollen dispersal in a shade coffee landscape mosaic.

    Science.gov (United States)

    Jha, Shalene; Dick, Christopher W

    2010-08-01

    Coffee farms are often embedded within a mosaic of agriculture and forest fragments in the world's most biologically diverse tropical regions. Although shade coffee farms can potentially support native pollinator communities, the degree to which these pollinators facilitate gene flow for native trees is unknown. We examined the role of native bees as vectors of gene flow for a reproductively specialized native tree, Miconia affinis, in a shade coffee and remnant forest landscape mosaic. We demonstrate extensive cross-habitat gene flow by native bees, with pollination events spanning more than 1,800 m. Pollen was carried twice as far within shade coffee habitat as in nearby forest, and trees growing within shade coffee farms received pollen from a far greater number of sires than trees within remnant forest. The study shows that shade coffee habitats support specialized native pollinators that enhance the fecundity and genetic diversity of remnant native trees.

  13. The long distance transport of airborne Ambrosia pollen to the UK and the Netherlands from Central and south Europe

    Science.gov (United States)

    de Weger, Letty A.; Pashley, Catherine H.; Šikoparija, Branko; Skjøth, Carsten A.; Kasprzyk, Idalia; Grewling, Łukasz; Thibaudon, Michel; Magyar, Donat; Smith, Matt

    2016-12-01

    The invasive alien species Ambrosia artemisiifolia (common or short ragweed) is increasing its range in Europe. In the UK and the Netherlands, airborne concentrations of Ambrosia pollen are usually low. However, more than 30 Ambrosia pollen grains per cubic metre of air (above the level capable to trigger allergic symptoms) were recorded in Leicester (UK) and Leiden (NL) on 4 and 5 September 2014. The aims of this study were to determine whether the highly allergenic Ambrosia pollen recorded during the episode could be the result of long distance transport, to identify the potential sources of these pollen grains and to describe the conditions that facilitated this possible long distance transport. Airborne Ambrosia pollen data were collected at 10 sites in Europe. Back trajectory and atmospheric dispersion calculations were performed using HYSPLIT_4. Back trajectories calculated at Leicester and Leiden show that higher altitude air masses (1500 m) originated from source areas on the Pannonian Plain and Ukraine. During the episode, air masses veered to the west and passed over the Rhône Valley. Dispersion calculations showed that the atmospheric conditions were suitable for Ambrosia pollen released from the Pannonian Plain and the Rhône Valley to reach the higher levels and enter the airstream moving to northwest Europe where they were deposited at ground level and recorded by monitoring sites. The study indicates that the Ambrosia pollen grains recorded during the episode in Leicester and Leiden were probably not produced by local sources but transported long distances from potential source regions in east Europe, i.e. the Pannonian Plain and Ukraine, as well as the Rhône Valley in France.

  14. LONG-DISTANCE GM POLLEN MOVEMENT OF CREEPING BENTGRASS USING MODELED WIND TRAJECTORY ANALYSIS

    Science.gov (United States)

    The importance of understanding the role of atmospheric conditions in pollen dispersal has grown in recent years with increased field-testing of genetically modified (GM) crop plants. An atmospheric model was used to characterize wind trajectories at 10 m and 100 m above GM polle...

  15. Intact plant magnetic resonance imaging to study dynamics in long-distance sap flow and flow-conducting surface area

    NARCIS (Netherlands)

    Scheenen, T.W.J.; Vergeldt, F.J.; Heemskerk, A.M.; As, van H.

    2007-01-01

    Due to the fragile pressure gradients present in the xylem and phloem, methods to study sap flow must be minimally invasive. Magnetic resonance imaging (MRI) meets this condition. A dedicated MRI method to study sap flow has been applied to quantify long-distance xylem flow and hydraulics in an

  16. Route optimisation and solving Zermelo’s navigation problem during long distance migration in cross flows

    DEFF Research Database (Denmark)

    Hays, Graeme C.; Christensen, Asbjørn; Fossette, Sabrina

    2014-01-01

    not follow the optimum (Zermelo's) route. Even though adult marine turtles regularly complete incredible long-distance migrations, these vertebrates primarily rely on course corrections when entering neritic waters during the final stages of migration. Our work introduces a new perspective in the analysis...

  17. Migration between continents: geographical structure and long-distance gene flow in Porpidia flavicunda (lichen-forming Ascomycota).

    Science.gov (United States)

    Buschbom, Jutta

    2007-05-01

    Historical and contemporary geographical distribution ranges with their associated gene flow patterns interact to produce the genetic diversity observed today. Often it is not possible to separate out the impacts of historical events, e.g. past fragmentation, and contemporary gene flow, e.g. long-distance dispersal. Porpidia flavicunda is a lichen-forming ascomycete occurring circumpolar in the boreal to arctic zones for which vegetation history suggests that its distribution pattern has stayed broadly the same over the past millennia. DNA-sequence diversity in P. flavicunda can, thus, be expected to predominantly represent geographical population differentiation and its contemporary migration rates. The population sample consists of 110 specimens collected in Northern Québec, Baffin Island, Western Greenland and Northern Scandinavia. DNA-sequence data sets of three nuclear gene fragments (LSU, RPB2 and beta-tubulin) were analysed for genetic diversity within, and differentiation between, geographical regions. Tests of population subdivision employing analyses of molecular variance and exact tests of haplotype frequency distributions showed significant structure between the geographical regions. However, the lack of fixed nucleotide polymorphisms and the wide sharing of identical haplotypes between geographical regions suggest recurrent long-distance gene flow of propagules. Still, the means by which propagules are dispersed remain to be discovered. Inference of migration rates shows that in many cases a sufficiently high amount of migrants is exchanged between geographical regions to prevent drastic population differentiation through genetic drift. The observed haplotype distributions and migration rates point to a gene flow model of isolation by distance.

  18. Parentage versus two-generation analyses for estimating pollen-mediated gene flow in plant populations.

    Science.gov (United States)

    Burczyk, Jaroslaw; Koralewski, Tomasz E

    2005-07-01

    Assessment of contemporary pollen-mediated gene flow in plants is important for various aspects of plant population biology, genetic conservation and breeding. Here, through simulations we compare the two alternative approaches for measuring pollen-mediated gene flow: (i) the NEIGHBORHOOD model--a representative of parentage analyses, and (ii) the recently developed TWOGENER analysis of pollen pool structure. We investigate their properties in estimating the effective number of pollen parents (N(ep)) and the mean pollen dispersal distance (delta). We demonstrate that both methods provide very congruent estimates of N(ep) and delta, when the methods' assumptions considering the shape of pollen dispersal curve and the mating system follow those used in data simulations, although the NEIGHBORHOOD model exhibits generally lower variances of the estimates. The violations of the assumptions, especially increased selfing or long-distance pollen dispersal, affect the two methods to a different degree; however, they are still capable to provide comparable estimates of N(ep). The NEIGHBORHOOD model inherently allows to estimate both self-fertilization and outcrossing due to the long-distance pollen dispersal; however, the TWOGENER method is particularly sensitive to inflated selfing levels, which in turn may confound and suppress the effects of distant pollen movement. As a solution we demonstrate that in case of TWOGENER it is possible to extract the fraction of intraclass correlation that results from outcrossing only, which seems to be very relevant for measuring pollen-mediated gene flow. The two approaches differ in estimation precision and experimental efforts but they seem to be complementary depending on the main research focus and type of a population studied.

  19. Genetic structure, mating system, and long-distance gene flow in heart of palm (Euterpe edulis Mart.).

    Science.gov (United States)

    Gaiotto, F A; Grattapaglia, D; Vencovsky, R

    2003-01-01

    We report a detailed analysis of the population genetic structure, mating system, and gene flow of heart of palm (Euterpe edulis Mart.-Arecaceae) in central Brazil. This palm is considered a keystone species because it supplies fruits for birds and rodents all year and is intensively harvested for culinary purposes. Two populations of this palm tree were examined, using 18 microsatellite loci. The species displays a predominantly outcrossed mating system (tm = 0.94), with a probability of full sibship greater than 70% within open-pollinated families. The following estimates of interpopulation genetic variation were calculated and found significant: FIT = 0.17, FIS = 0.12, FST = 0.06, and RST = 0.07. This low but significant level of interpopulation genetic variation indicates high levels of gene flow. Two adult trees were identified as likely seed parents (P > 99.9%) of juveniles located at a distance of 22 km. Gene flow over such distances has not been reported before for tropical tree species. The establishment and management of in situ genetic reserves or ex situ conservation and breeding populations for E. edulis should contemplate the collection of several hundreds open-pollinated maternal families from relatively few distant populations to maximize the genetic sampling of a larger number of pollen parents.

  20. Flow dynamics in mid-Jurassic dikes and sills of the Ferrar large igneous province and implications for long-distance magma transport

    Science.gov (United States)

    Airoldi, Giulia M.; Muirhead, James D.; Long, Sylvan M.; Zanella, Elena; White, James D. L.

    2016-06-01

    Magma flow paths in sill-fed dikes of the Ferrar large igneous province (LIP), contrast with those predicted by classic models of dike transport in LIPs and magmatic rift settings. We examine anisotropy of magnetic susceptibility (AMS) flow paths in dike networks at Terra Cotta Mountain and Mt. Gran, which intruded at paleodepths of ~ 2.5 and ~ 1.5 km. These intrusions (up to 30 m thick) exhibit irregular, interconnected dike-sill geometries and adjoin larger sills (~ 200-300 m thick) at different stratigraphic levels. Both shallowly dipping and sub-vertical magma flow components are interpreted from AMS measurements across individual intrusions, and often match macroscopic flow indicators and variations in dike attitudes. Flow paths suggest that intrusive patterns and magma flow directions depended on varying stress concentrations and rotations during dike and sill propagation, whereas a regional extensional tectonic control was negligible or absent. Unlike giant dike swarms in LIPs elsewhere (e.g., 1270 Ma MacKenzie LIP), dikes of the Ferrar LIP show no regionally consistent vertical or lateral flow patterns, suggesting these intrusion were not responsible for long-distance transport in the province. In the absence of regionally significant, colinear dike swarms, or observed intrusions at crustal depths ≥ 4 km, we suggest that long distance magma transport occurred in sills within Beacon Supergroup sedimentary rocks. This interpretation is consistent with existing geochemical data and thermal constraints, which support lateral magma flow for ~ 3,500 km across the Gondwana supercontinent before freezing.

  1. Long distance tunneling

    CERN Document Server

    Ivlev, B I

    2005-01-01

    Quantum tunneling between two potential wells in a magnetic field can be strongly increased when the potential barrier varies in the direction perpendicular to the line connecting the two wells and remains constant along this line. A periodic structure of the wave function is formed in the direction joining the wells. The resulting motion can be coherent like motion in a conventional narrow band periodic structure. A particle penetrates the barrier over a long distance which strongly contrasts to WKB-like tunneling. The whole problem is stationary. The coherent process can be influenced by dissipation.

  2. Flowering phenology, pollen flow and fruit production in the andean shrub Befaria resinosa.

    Science.gov (United States)

    Melampy, M N

    1987-09-01

    In the eastern Andes of Colombia, the shrub Befaria resinosa (Ericaceae) has peaks of flowering that are separated by extended periods of low flower production. The effect that these fluctuations in flower production have on pollen flow was investigated by using fluorescent dye as a pollen analog. Dye applied to open flowers was dispersed over long distances more often during low flower production than during high flower production. Whether enhanced pollen dispersal during flowering lows is of benefit to individual plants is not clear. The proportion of flowers that set fruit is positively correlated with flower abundance, negating the possibility that increased pollen dispersal results in a higher rate of fruit production due to outbreeding effects. It is also difficult to attribute the pattern of fruit production to changes in pollinator visitation rates, which are negatively correlated with flower abundance in the case of hummingbirds and not correlated at all with flower abundance in the case of insects. An opportunistic, large-bodied hummingbird (Colibri coruscans) visits B. resinosa during high flowering and may be a particularly effective pollinator, accounting for some of the increase in the proportion of flowers setting fruit. Rainfall is positively correlated with flower production and may be an important factor in shaping flowering phenology, but it is not significantly correlated with the proportion of flowers setting fruits. The possibility that low-level flowering may counteract inbreeding that results from peak flowering is discussed.

  3. Impedance Flow Cytometry: A Novel Technique in Pollen Analysis.

    Science.gov (United States)

    Heidmann, Iris; Schade-Kampmann, Grit; Lambalk, Joep; Ottiger, Marcel; Di Berardino, Marco

    2016-01-01

    An efficient and reliable method to estimate plant cell viability, especially of pollen, is important for plant breeding research and plant production processes. Pollen quality is determined by classical methods, like staining techniques or in vitro pollen germination, each having disadvantages with respect to reliability, analysis speed, and species dependency. Analysing single cells based on their dielectric properties by impedance flow cytometry (IFC) has developed into a common method for cellular characterisation in microbiology and medicine during the last decade. The aim of this study is to demonstrate the potential of IFC in plant cell analysis with the focus on pollen. Developing and mature pollen grains were analysed during their passage through a microfluidic chip to which radio frequencies of 0.5 to 12 MHz were applied. The acquired data provided information about the developmental stage, viability, and germination capacity. The biological relevance of the acquired IFC data was confirmed by classical staining methods, inactivation controls, as well as pollen germination assays. Different stages of developing pollen, dead, viable and germinating pollen populations could be detected and quantified by IFC. Pollen viability analysis by classical FDA staining showed a high correlation with IFC data. In parallel, pollen with active germination potential could be discriminated from the dead and the viable but non-germinating population. The presented data demonstrate that IFC is an efficient, label-free, reliable and non-destructive technique to analyse pollen quality in a species-independent manner.

  4. Impedance Flow Cytometry: A Novel Technique in Pollen Analysis

    OpenAIRE

    Heidmann, Iris; Schade-Kampmann, Grit; Lambalk, Joep; Ottiger, Marcel; Di Berardino, Marco

    2016-01-01

    Introduction An efficient and reliable method to estimate plant cell viability, especially of pollen, is important for plant breeding research and plant production processes. Pollen quality is determined by classical methods, like staining techniques or in vitro pollen germination, each having disadvantages with respect to reliability, analysis speed, and species dependency. Analysing single cells based on their dielectric properties by impedance flow cytometry (IFC) has developed into a comm...

  5. Pollen flow of wheat under natural conditions in the Huanghuai River Wheat Region, China

    OpenAIRE

    Sun, Ai-Qing; Zhang, Chun-Qing; Wu, Cheng-Lai; Gao, Qing-Rong

    2015-01-01

    The transgenic pollen spread is the main pathway of transgenic plant gene flow. The maximum distance of pollen dispersal (horizontal), the spatial dynamics of pollen movement (vertical), and the patterns of pollen dispersal are important considerations in biosafety assessments of genetically modified crops. To evaluate wheat (Triticum aestivum) pollen dispersal, we measured the pollen suspension velocity and analyzed pollen dispersal patterns under natural conditions in the Huanghuai River wh...

  6. Extensive pollen flow but few pollen donors and high reproductive variance in an extremely fragmented landscape.

    Directory of Open Access Journals (Sweden)

    Rafael G Albaladejo

    Full Text Available Analysing pollen movement is a key to understanding the reproductive system of plant species and how it is influenced by the spatial distribution of potential mating partners in fragmented populations. Here we infer parameters related to levels of pollen movement and diversity of the effective pollen cloud for the wind-pollinated shrub Pistacia lentiscus across a highly disturbed landscape using microsatellite loci. Paternity analysis and the indirect KinDist and Mixed Effect Mating models were used to assess mating patterns, the pollen dispersal kernel, the effective number of males (N(ep and their relative individual fertility, as well as the existence of fine-scale spatial genetic structure in adult plants. All methods showed extensive pollen movement, with high rates of pollen flow from outside the study site (up to 73-93%, fat-tailed dispersal kernels and large average pollination distances (δ = 229-412 m. However, they also agreed in detecting very few pollen donors (N(ep = 4.3-10.2 and a large variance in their reproductive success: 70% of males did not sire any offspring among the studied female plants and 5.5% of males were responsible for 50% of pollinations. Although we did not find reduced levels of genetic diversity, the adult population showed high levels of biparental inbreeding (14% and strong spatial genetic structure (S(p = 0.012, probably due to restricted seed dispersal and scarce safe sites for recruitment. Overall, limited seed dispersal and the scarcity of successful pollen donors can be contributing to generate local pedigrees and to increase inbreeding, the prelude of genetic impoverishment.

  7. Pollen flow of wheat under natural conditions in the Huanghuai River Wheat Region, China.

    Science.gov (United States)

    Sun, Ai-Qing; Zhang, Chun-Qing; Wu, Cheng-Lai; Gao, Qing-Rong

    2015-01-01

    The transgenic pollen spread is the main pathway of transgenic plant gene flow. The maximum distance of pollen dispersal (horizontal), the spatial dynamics of pollen movement (vertical), and the patterns of pollen dispersal are important considerations in biosafety assessments of genetically modified crops. To evaluate wheat (Triticum aestivum) pollen dispersal, we measured the pollen suspension velocity and analyzed pollen dispersal patterns under natural conditions in the Huanghuai River wheat-growing region in 2009. The pollen suspension velocity was 0.3-0.4 m/s. The highest pollen densities were detected in the north, northwest, and south of the pollen source. Pollen was dispersed over distances greater than 245 m in the northwest and northeast directions. At the pollen source center, pollen density decreased with increasing vertical height. In the north of the pollen source, the pollen density from 65 m to 225 m showed a wave-mode decrease with increasing height. The horizontal transport of pollen over longer distances fitted polynomial equations. In the north, the pollen density was highest at 45 m from the pollen source, and decreased with increasing distance. In the northwest, the pollen density showed a double-peak trend. In the northeast, pollen density was highest from 45 m to 125 m from the source. Wind speeds greater than the pollen suspension velocity and the duration of continuous gusts were the main factors affecting pollen dispersal. This information will be useful for determining the spatial isolation distances for hybrid seed production and for the commercial production of transgenic wheat.

  8. Green hydrophilic modification of PE hollow fiber membranes in a module scale via long-distance and dynamic low-temperature H2O plasma flow

    Science.gov (United States)

    Li, Mei-Sheng; Zhao, Zhi-Ping; Wang, Ming-Xing

    2016-11-01

    A green chemistry process, long-distance and dynamic low-temperature (LDDLT) H2O plasma, was developed to modify PE hollow fiber membranes in a module scale using our modified LDDLT plasma setup. The modification degree of LDDLT-H2O plasma was 2 times greater than that of Ar plasma, but the effective treatment distance achieved by LDDLT-Ar plasma was about two times of that obtained by LDDLT-H2O plasma (22 cm). Under the suitable conditions, the effective treatment distance can reach over 54 cm after LDDLT-H2O plasma treatment from the double inlets, closed to some industrial module sizes. The improvement in surface hydrophilicity was because of the introduction of numerous oxygen-containing groups. High concentrations of OH radicals in H2O plasma played a major role in the membrane surface hydroxylation. This directly resulted in a great enhancement in the pure water flux. It increased from about 6 L m-2 h-1 to 45 L m-2 h-1 after treatment. Also, the H2O plasma-treated membrane module exhibited good hydrophilic stability during 285 days storage.

  9. Investigating Pollen and Gene Flow of WYMV-Resistant Transgenic Wheat N12-1 Using a Dwarf Male-Sterile Line as the Pollen Receptor.

    Directory of Open Access Journals (Sweden)

    Shanshan Dong

    Full Text Available Pollen-mediated gene flow (PMGF is the main mode of transgene flow in flowering plants. The study of pollen and gene flow of transgenic wheat can help to establish the corresponding strategy for preventing transgene escape and contamination between compatible genotypes in wheat. To investigate the pollen dispersal and gene flow frequency in various directions and distances around the pollen source and detect the association between frequency of transgene flow and pollen density from transgenic wheat, a concentric circle design was adopted to conduct a field experiment using transgenic wheat with resistance to wheat yellow mosaic virus (WYMV as the pollen donor and dwarf male-sterile wheat as the pollen receptor. The results showed that the pollen and gene flow of transgenic wheat varied significantly among the different compass sectors. A higher pollen density and gene flow frequency was observed in the downwind SW and W sectors, with average frequencies of transgene flow of 26.37 and 23.69% respectively. The pollen and gene flow of transgenic wheat declined dramatically with increasing distance from its source. Most of the pollen grains concentrated within 5 m and only a few pollen grains were detected beyond 30 m. The percentage of transgene flow was the highest where adjacent to the pollen source, with an average of 48.24% for all eight compass directions at 0 m distance. Transgene flow was reduced to 50% and 95% between 1.61 to 3.15 m, and 10.71 to 20.93 m, respectively. Our results suggest that climate conditions, especially wind direction, may significantly affect pollen dispersal and gene flow of wheat. The isolation-by-distance model is one of the most effective methods for achieving stringent transgene confinement in wheat. The frequency of transgene flow is directly correlated with the relative density of GM pollen grains in air currents, and pollen competition may be a major factor influencing transgene flow.

  10. Elasticity of Long Distance Travelling

    DEFF Research Database (Denmark)

    Knudsen, Mette Aagaard

    2011-01-01

    With data from the Danish expenditure survey for 12 years 1996 through 2007, this study analyses household expenditures for long distance travelling. Household expenditures are examined at two levels of aggregation having the general expenditures on transportation and leisure relative to five other...... aggregated commodities at the highest level, and the specific expenditures on plane tickets and travel packages at the lowest level. The Almost Ideal Demand System is applied to determine the relationship between expenditures on transportation and leisure and all other purchased non-durables within...... packages has higher income elasticity of demand than plane tickets but also higher than transportation and leisure in general. The findings within price sensitiveness are not as sufficient estimated, but the model results indicate that travel packages is far more price elastic than plane tickets which...

  11. Pollen

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Records of past vegetation and climate derived from pollen found in lake and ocean sediments. Parameter keywords describe what was measured in this data set....

  12. MRI of long-distance water transport: a comparison of the phloem and xylem flow characteristics and dynamics in poplar, castor bean, tomato and tobacco

    NARCIS (Netherlands)

    Windt, C.W.; Vergeldt, F.J.; Jager, de P.A.; As, van H.

    2006-01-01

    We used dedicated magnetic resonance imaging (MRI) equipment and methods to study phloem and xylem transport in large potted plants. Quantitative flow profiles were obtained on a per-pixel basis, giving parameter maps of velocity, flow-conducting area and volume flow (flux). The diurnal xylem and

  13. Binding Principle for Long-Distance Anaphors.

    Science.gov (United States)

    Choi, Dong-Ik

    1997-01-01

    An analysis of long-distance anaphora, a binding phenomenon in which reflexives find their antecedents outside their local domain, is presented, using data from English, Chinese, Japanese, Korean, Russian, Icelandic, and Italian. It is found that no approach deals with long-distance anaphors exclusively and elegantly. The binding domain…

  14. Migratory beekeeping practices contribute insignificantly to transgenic pollen flow among fields of alfalfa produced for seed

    Science.gov (United States)

    Increased use of genetically engineered crops in agriculture has raised concerns over pollinator-mediated gene flow between transgenic and conventional agricultural varieties. This study evaluated whether contracted migratory beekeeping practices influence transgenic pollen flow among spatially iso...

  15. Long distance travel ‘today’

    DEFF Research Database (Denmark)

    Christensen, Linda

    2014-01-01

    This paper presents an overview of the Dane’s long distance travel. It is a part of the Drivers and Limits project about long distance travel. Long distance travel is in the project defined as infrequent travel with overnight stay. Danes 15-85 years-old travel in average 5.5 long distance travel...... per year og which a third is for international destinations, a third is for domestic second homes and a third are other domestic trips. However, 87% of the kilometres are for international destinations and only 4% are for domestic second homes. Travel activity is very uneven distributed with only half...... of the population having had a journey during the last three month. At the other hand 60% have travelled internationally during the last year and only 2% have never travelled abroad. The paper presents among other things how the travel activity is distributed on travel purpose and mode and how the mode choice...

  16. Long distance signaling using axionlike particles

    Science.gov (United States)

    Stancil, Daniel D.

    2007-12-01

    The possible existence of axionlike particles could lead to a new type of long-distance communication. In this work, basic antenna concepts are defined and a Friis-like equation is derived to facilitate long-distance link calculations. An example calculation is presented showing that communication over distances of 1000 km or more may be possible for ma5×10-8GeV-1.

  17. Impedance Flow Cytometry as a Tool to Analyze Microspore and Pollen Quality.

    Science.gov (United States)

    Heidmann, Iris; Di Berardino, Marco

    2017-01-01

    Analyzing pollen quality in an efficient and reliable manner is of great importance to the industries involved in seed and fruit production, plant breeding, and plant research. Pollen quality parameters, viability and germination capacity, are analyzed by various staining methods or by in vitro germination assays, respectively. These methods are time-consuming, species-dependent, and require a lab environment. Furthermore, the obtained viability data are often poorly related to in vivo pollen germination and seed set. Here, we describe a quick, label-free method to analyze pollen using microfluidic chips inserted into an impedance flow cytometer (IFC). Using this approach, pollen quality parameters are determined by a single measurement in a species-independent manner. The advantage of this protocol is that pollen viability and germination can be analyzed quickly by a reliable and standardized method.

  18. Host Plants Identification for Adult Agrotis ipsilon, a Long-Distance Migratory Insect

    Directory of Open Access Journals (Sweden)

    Yongqiang Liu

    2016-06-01

    Full Text Available In this study, we determined the host relationship of Agrotis ipsilon moths by identifying pollen species adhering them during their long-distance migration. Pollen carried by A. ipsilon moths was collected from 2012 to 2014 on a small island in the center of the Bohai Strait, which is a seasonal migration pathway of this pest species. Genomic DNA of single pollen grains was amplified by using whole genome amplification technology, and a portion of the chloroplast rbcL sequence was then amplified from this material. Pollen species were identified by a combination of DNA barcoding and pollen morphology. We found 28 species of pollen from 18 families on the tested moths, mainly from Angiosperm, Dicotyledoneae. From this, we were able to determine that these moths visit woody plants more than herbaceous plants that they carry more pollen in the early and late stages of the migration season, and that the amounts of pollen transportation were related to moth sex, moth body part, and plant species. In general, 31% of female and 26% of male moths were found to be carrying pollen. Amounts of pollen on the proboscis was higher for female than male moths, while the reverse was true for pollen loads on the antennae. This work provides a new approach to study the interactions between noctuid moth and their host plants. Identification of plant hosts for adult moths furthers understanding of the coevolution processes between moths and their host plants.

  19. Environmental Impact of Long Distance Travel

    DEFF Research Database (Denmark)

    Christensen, Linda

    2016-01-01

    This paper presents an analysis of the CO2 emission resulting from long distance travel by Danes. The emissions are analysed as the Danes’ footprint the whole way from Denmark to the final destination. International travel represents 31% of the Danes’ CO2 emission from passenger travel and the cl......This paper presents an analysis of the CO2 emission resulting from long distance travel by Danes. The emissions are analysed as the Danes’ footprint the whole way from Denmark to the final destination. International travel represents 31% of the Danes’ CO2 emission from passenger travel...... and the climate burden from long overseas distances is especially high even though only few travel overseas. The travel activity is furthermore increasing much more for long distances than for European destinations. Domestic travel activity with overnight stay is nearly stagnating. The study furthermore shows...

  20. Hybrid Long-Distance Entanglement Distribution Protocol

    DEFF Research Database (Denmark)

    Brask, J.B.; Rigas, I.; Polzik, E.S.;

    2010-01-01

    We propose a hybrid (continuous-discrete variable) quantum repeater protocol for long-distance entanglement distribution. Starting from states created by single-photon detection, we show how entangled coherent state superpositions can be generated by means of homodyne detection. We show that near...

  1. Large eddy simulation of atmospheric boundary layer flows and application to pollen dispersal

    Science.gov (United States)

    Chamecki, Marcelo

    This work presents a framework for simulating pollen dispersal by wind based on Large Eddy Simulation. Important phenomena such as pollen emission by plants and ground deposition are modeled through the boundary condition. An expression for the vertical equilibrium concentration profile of pollen particles, including the effect of the canopy on the eddy diffusivity as well as corrections for atmospheric stability, is proposed for this purpose. This expression is validated against measurements of vertical concentration profiles of corn pollen above a corn field. The numerical discretization of the evolution equations follows a new approach in which different discretization schemes are used for the velocity and concentration fields. A new interpolation scheme is proposed to couple the two discretizations. The numerical model is validated against previously published experiments of point-source releases of glass beads and pollen grains in the atmospheric boundary layer. The numerical model is used together with experimental data of pollen emission and downwind deposition from a natural field obtained near Washington DC in the summer of 2006. The combined analysis of experimental and numerical data elucidates the emission, transport, and deposition processes in considerable detail. In particular, the relative fractions of pollen deposited inside the source field and airborne at the edge of the field can be quantified. Investigations based on experimental data and direct numerical simulation of the effects of the local structure of the flow on subgrid scale models for simulations of the atmospheric boundary layer are also presented.

  2. 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.

  3. TCP-Adaptive in High Speed Long Distance Networks

    Directory of Open Access Journals (Sweden)

    Quan Liu

    2014-02-01

    Full Text Available With the development of high performance computing and increasing of network bandwidth, more and more applications require fast data transfer over high-speed long-distance networks. Research shows that the standard TCP Reno cannot fulfill the requirement of fast transfer of massive data due to its conservative congestion control mechanism. Some works have been proposed to improve the TCP throughput performance using more aggressive window increasing tactics and obtain substantial achievements. However, they cannot be strictly proved to be comprehensively suitable for high-speed complex network environments. In this paper, we propose TCP-Adaptive, an adaptive congestion control algorithm adjusting the increasing congestion window dynamically. The algorithm improves logarithmic detection procedure for available bandwidth in the flow path by distinguishing the first detection in congestion avoidance and retransmission timeout. On the other hand, an adaptive control algorithm is proposed to achieve better performance in high-speed long-distance networks. The algorithm uses round trip time (RTT variations to predict the congestion trends to update the increments of congestion window. Simulations verify the property of TCP-Adaptive and show satisfying performance in throughput, RTT fairness aspects over high-speed long-distance networks. Especially in sporadic loss environment, TCP-Adaptive shows a significant adaptability with the variations of link quality

  4. POLLEN FLOW IN THE ENVIRONMENT - DEVELOPMENT OF A RESEARCH PROGRAM

    Science.gov (United States)

    The USEPA Office of Research and Development seeks to provide to the agency and society the best information relating to the status of the environment and any related technology maintaining environmental quality. In this effort, a recent research workshop (Pollen Mediated Gene Fl...

  5. Long distance electron transmission in marine sediment

    DEFF Research Database (Denmark)

    Risgaard-Petersen, Nils; Nielsen, Lars Peter

    processes leads to formation of electrical fields, which modifies ion transport. The local proton producing and proton consuming half reactions induces pH extremes that accelerate dissolution of iron sul-phides and calcium carbonates in anoxic layers and promotes the formation of Mg-calcite and iron oxides...... in the oxic zone. Oxygen seems to be the major electron acceptor in the coupled system, and more than 40% of the oxygen consumption can be driven by long distance electron transmission. The major e-donor is sulfide, which is oxidized to sulfate, and iron sulphides are the major sources for sulfide...

  6. Long distance animal transport: the way forward

    Directory of Open Access Journals (Sweden)

    Klaas Johan Osinga

    2008-03-01

    Full Text Available Too often, the issue of animal welfare during transport is the subject of emotional debates. For farmers within the International Federation of Agricultural Producers, it is important that the economic, scientific and practical aspects be taken into account when setting international rules for animal welfare. Farmers also stress the need to combine scientific data with their practical experience. Raising awareness, adopting a risk-based approach, education, labelling, slaughterhouse capacity and animal health, as well as standards and rules, are issues of importance for developing a long distance transportation infrastructure respectful of animal welfare around the world.

  7. Satellite Communication and Long Distance Education

    Directory of Open Access Journals (Sweden)

    Hafied Cangara

    2016-02-01

    Full Text Available Since Indonesia introduced communication satellite for telecommunication network, the satellite has brought a number of advantages for national development in various areas, such as telephone network, mass media development, business, education, politics, security and national defence as well as regional and international cooperation. In education, satellite communication could be used for long-distance learning as implemented by 13 state universities in eastern parts of Indonesia. It is also possible to develop the Open University System in teaching and learning process, particularly since the internet technology has been intensively used

  8. Pollen dispersal in sugar beet production fields.

    Science.gov (United States)

    Darmency, Henri; Klein, Etienne K; De Garanbé, Thierry Gestat; Gouyon, Pierre-Henri; Richard-Molard, Marc; Muchembled, Claude

    2009-04-01

    Pollen-mediated gene flow has important implications for biodiversity conservation and for breeders and farmers' activities. In sugar beet production fields, a few sugar beet bolters can produce pollen as well as be fertilized by wild and weed beet. Since the crop, the wild beets, and the weed beets are the same species and intercross freely, the question of pollen flow is an important issue to determine the potential dispersal of transgenes from field to field and to wild habitats. We report here an experiment to describe pollen dispersal from a small herbicide-resistant sugar beet source towards male sterile target plants located along radiating lines up to 1,200 m away. Individual dispersal functions were inferred from statistical analyses and compared. Pollen limitation, as expected in root-production fields, was confirmed at all the distances from the pollen source. The number of resistant seeds produced by bait plants best fitted a fat-tailed probability distribution curve of pollen grains (power-law) dependent on the distance from the pollen source. A literature survey confirmed that power-law function could fit in most cases. The b coefficient was lower than 2. The number of fertilized flowers by background (herbicide-susceptible) pollen grains was uniform across the whole field. Airborne pollen had a fertilization impact equivalent to that of one adjacent bolter. The individual dispersal function from different pollen sources can be integrated to provide the pollen cloud composition for a given target plant, thus allowing modeling of gene flow in a field, inter-fields in a small region, and also in seed-production area. Long-distance pollen flow is not negligible and could play an important role in rapid transgene dispersal from crop to wild and weed beets in the landscape. The removing of any bolting, herbicide-resistant sugar beet should be compulsory to prevent the occurrence of herbicide-resistant weed beet, thus preventing gene flow to wild

  9. Gene flow from transgenic oilseed rape (Brassica napus L.) to cruciferous weeds under mentor pollen inducement

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The alien gene flow between genetically modified glyphosate-resistant rapeseed variety Q3 ( Brassica napus L. ) and four cruciferous weeds was studied under mentor pollen inducement. The results showed that when Thlaspi arvense L., Capsella bursapastoris (L.) Medic, Cardamine hirsuta L. and Rorippa palustris (L.) Besser were pollinated with mentor pollen, the mixed Q3 and the weed, pollen grains aggregated largely and germinated quickly, and the numbers of pollen tubes penetrating into the style and the ovary were greatly increased as compared with corresponding self-pollination groups. Twenty four to forty eight hours after pollination, several pollen tubes were observed to penetrate into the ovule via micropyle in each mentor combination. However, when the mentor progenies were analyzed by PCR, all of them showed negative for the Q3 herbicide-resistant gene. Collectively, these results indicated that crossing between T. arvense, C. bursa-pastoris, C. hirsuta, R. palustris (as female) and Q3 (as male) was highly incompatible and the herbicide-resistant gene could not flow from Q3 to these four weeds.

  10. Optimal architectures for long distance quantum communication.

    Science.gov (United States)

    Muralidharan, Sreraman; Li, Linshu; Kim, Jungsang; Lütkenhaus, Norbert; Lukin, Mikhail D; Jiang, Liang

    2016-02-15

    Despite the tremendous progress of quantum cryptography, efficient quantum communication over long distances (≥ 1000 km) remains an outstanding challenge due to fiber attenuation and operation errors accumulated over the entire communication distance. Quantum repeaters (QRs), as a promising approach, can overcome both photon loss and operation errors, and hence significantly speedup the communication rate. Depending on the methods used to correct loss and operation errors, all the proposed QR schemes can be classified into three categories (generations). Here we present the first systematic comparison of three generations of quantum repeaters by evaluating the cost of both temporal and physical resources, and identify the optimized quantum repeater architecture for a given set of experimental parameters for use in quantum key distribution. Our work provides a roadmap for the experimental realizations of highly efficient quantum networks over transcontinental distances.

  11. Focus characteristics of long distance flying optics

    Institute of Scientific and Technical Information of China (English)

    程兆谷; 蒋金波; 李现勤; 许国良; 夏金安; W.M.Steen; G.Dearden

    2000-01-01

    The ABCD law for the complex parameter q of the TEM00 Gaussian beam is generally not valid for high-order modes. It can be used for the high-order modes or their superposition when the spot size w in the virtual part of the parameter q is substituted by the Rayleigh range ZR of a certain resonator. The focus characteristics of long distance flying optics are studied in this paper theoretically and experimentally for the TEMmn Gaussian beams between the two types of resonators without and with distortion. It is very important for the applications of the flying optical processing, the laser space craft and the spatial filter in the large laser project.

  12. Optimal architectures for long distance quantum communication

    Science.gov (United States)

    Muralidharan, Sreraman; Li, Linshu; Kim, Jungsang; Lütkenhaus, Norbert; Lukin, Mikhail D.; Jiang, Liang

    2016-02-01

    Despite the tremendous progress of quantum cryptography, efficient quantum communication over long distances (≥1000 km) remains an outstanding challenge due to fiber attenuation and operation errors accumulated over the entire communication distance. Quantum repeaters (QRs), as a promising approach, can overcome both photon loss and operation errors, and hence significantly speedup the communication rate. Depending on the methods used to correct loss and operation errors, all the proposed QR schemes can be classified into three categories (generations). Here we present the first systematic comparison of three generations of quantum repeaters by evaluating the cost of both temporal and physical resources, and identify the optimized quantum repeater architecture for a given set of experimental parameters for use in quantum key distribution. Our work provides a roadmap for the experimental realizations of highly efficient quantum networks over transcontinental distances.

  13. Long-distance effects of insertional mutagenesis.

    Directory of Open Access Journals (Sweden)

    Ruchi Singhal

    Full Text Available BACKGROUND: Most common systems of genetic engineering of mammalian cells are associated with insertional mutagenesis of the modified cells. Insertional mutagenesis is also a popular approach to generate random alterations for gene discovery projects. A better understanding of the interaction of the structural elements within an insertional mutagen and the ability of such elements to influence host genes at various distances away from the insertion site is a matter of considerable practical importance. METHODOLOGY/PRINCIPAL FINDINGS: We observed that, in the context of a lentiviral construct, a transcript, which is initiated at an internal CMV promoter/enhancer region and incorporates a splice donor site, is able to extend past a collinear viral LTR and trap exons of host genes, while the polyadenylation signal, which is naturally present in the LTR, is spliced out. Unexpectedly, when a vector, which utilizes this phenomenon, was used to produce mutants with elevated activity of NF-κB, we found mutants, which owed their phenotype to the effect of the insert on a gene located tens or even hundreds of kilobases away from the insertion site. This effect did not result from a CMV-driven transcript, but was sensitive to functional suppression of the insert. Interestingly, despite the long-distance effect, expression of loci most closely positioned to the insert appeared unaffected. CONCLUSIONS/SIGNIFICANCE: We concluded that a polyadenylation signal in a retroviral LTR, when occurring within an intron, is an inefficient barrier against the formation of a hybrid transcript, and that a vector containing a strong enhancer may selectively affect the function of genes far away from its insertion site. These phenomena have to be considered when experimental or therapeutic transduction is performed. In particular, the long-distance effects of insertional mutagenesis bring into question the relevance of the lists of disease-associated retroviral integration

  14. Pollen- and seed-mediated transgene flow in commercial cotton seed production fields.

    Directory of Open Access Journals (Sweden)

    Shannon Heuberger

    Full Text Available BACKGROUND: Characterizing the spatial patterns of gene flow from transgenic crops is challenging, making it difficult to design containment strategies for markets that regulate the adventitious presence of transgenes. Insecticidal Bacillus thuringiensis (Bt cotton is planted on millions of hectares annually and is a potential source of transgene flow. METHODOLOGY/PRINCIPAL FINDINGS: Here we monitored 15 non-Bt cotton (Gossypium hirsutum, L. seed production fields (some transgenic for herbicide resistance, some not for gene flow of the Bt cotton cry1Ac transgene. We investigated seed-mediated gene flow, which yields adventitious Bt cotton plants, and pollen-mediated gene flow, which generates outcrossed seeds. A spatially-explicit statistical analysis was used to quantify the effects of nearby Bt and non-Bt cotton fields at various spatial scales, along with the effects of pollinator abundance and adventitious Bt plants in fields, on pollen-mediated gene flow. Adventitious Bt cotton plants, resulting from seed bags and planting error, comprised over 15% of plants sampled from the edges of three seed production fields. In contrast, pollen-mediated gene flow affected less than 1% of the seed sampled from field edges. Variation in outcrossing was better explained by the area of Bt cotton fields within 750 m of the seed production fields than by the area of Bt cotton within larger or smaller spatial scales. Variation in outcrossing was also positively associated with the abundance of honey bees. CONCLUSIONS/SIGNIFICANCE: A comparison of statistical methods showed that our spatially-explicit analysis was more powerful for understanding the effects of surrounding fields than customary models based on distance. Given the low rates of pollen-mediated gene flow observed in this study, we conclude that careful planting and screening of seeds could be more important than field spacing for limiting gene flow.

  15. Life history and past demography maintain genetic structure, outcrossing rate, contemporary pollen gene flow of an understory herb in a highly fragmented rainforest

    Directory of Open Access Journals (Sweden)

    Pilar Suárez-Montes

    2016-12-01

    Full Text Available Introduction Theory predicts that habitat fragmentation, by reducing population size and increasing isolation among remnant populations, can alter their genetic diversity and structure. A cascade of effects is expected: genetic drift and inbreeding after a population bottleneck, changes in biotic interactions that may affect, as in the case of plants, pollen dynamics, mating system, reproductive success. The detection of the effects of contemporary habitat fragmentation on the genetic structure of populations are conditioned by the magnitude of change, given the few number of generations since the onset of fragmentation, especially for long-lived organisms. However, the present-day genetic structure of populations may bear the signature of past demography events. Here, we examine the effects of rainforest fragmentation on the genetic diversity, population structure, mating system (outcrossing rate, indirect gene flow and contemporary pollen dynamics in the understory herb Aphelandra aurantiaca. Also, we assessed its present-day genetic structure under different past demographic scenarios. Methods Twelve populations of A. aurantiaca were sampled in large (4, medium (3, and small (5 forest fragments in the lowland tropical rainforest at Los Tuxtlas region. Variation at 11 microsatellite loci was assessed in 28–30 reproductive plants per population. In two medium- and two large-size fragments we estimated the density of reproductive plants, and the mating system by analyzing the progeny of different mother plants per population. Results Despite prevailing habitat fragmentation, populations of A. aurantiaca possess high genetic variation (He = 0.61, weak genetic structure (Rst = 0.037, and slight inbreeding in small fragments. Effective population sizes (Ne were large, but slightly lower in small fragments. Migrants derive mostly from large and medium size fragments. Gene dispersal is highly restricted but long distance gene dispersal events

  16. A model of plasma membrane flow and cytosis regulation in growing pollen tubes.

    Science.gov (United States)

    Chavarría-Krauser, Andrés; Yejie, Du

    2011-09-21

    A model of cytosis regulation in growing pollen tubes is developed and simulations presented. The authors address the question on the minimal assumptions needed to describe the pattern of exocytosis and endocytosis reported recently by experimental biologists. Biological implications of the model are also treated. Concepts of flow and conservation of membrane material are used to pose an equation system, which describes the movement of plasma membrane in the tip of growing pollen tubes. After obtaining the central equations, relations describing the rates of endocytosis and exocytosis are proposed. Two cytosis receptors (for exocytosis and endocytosis), which have different recycling rates and activation times, suffice to describe a stable growing tube. Simulations show a very good spatial separation between endocytosis and exocytosis, in which separation is shown to depend strongly on exocytic vesicle delivery. In accordance to measurements, most vesicles in the clear zone are predicted to be endocytic. Membrane flow is essential to maintain cell polarity, and bi-directional flow seems to be a natural consequence of the proposed mechanism. For the first time, a model addressing plasma membrane flow and cytosis regulation were posed. Therefore, it represents a missing piece in an integrative model of pollen tube growth, in which cell wall mechanics, hydrodynamic fluxes and regulation mechanisms are combined.

  17. Impedance Flow Cytometry: A Novel Technique in Pollen Analysis

    National Research Council Canada - National Science Library

    Heidmann, Iris; Schade-Kampmann, Grit; Lambalk, Joep; Ottiger, Marcel; Di Berardino, Marco

    2016-01-01

    .... Analysing single cells based on their dielectric properties by impedance flow cytometry (IFC) has developed into a common method for cellular characterisation in microbiology and medicine during the last decade...

  18. Dynamics of Long-distance Signaling via Plant Vascular Tissues

    Directory of Open Access Journals (Sweden)

    Michitaka eNotaguchi

    2015-03-01

    Full Text Available Plant vascular systems are constructed by specific cell wall modifications through which cells are highly specialized to make conduits for water and nutrients. Xylem vessels are formed by thickened cell walls that remain after programmed cell death, and serve as water conduits from the root to the shoot. In contrast, phloem tissues consist of a complex of living cells, including sieve tube elements and their neighboring companion cells, and translocate photosynthetic assimilates from mature leaves to developing young tissues. Intensive studies on the content of vascular flow fluids have unveiled that plant vascular tissues transport various types of gene product, and the transport of some provides the molecular basis for the long-distance communications. Analysis of xylem sap has demonstrated the presence of proteins in the xylem transpiration stream. Recent studies have revealed that CLE and CEP peptides secreted in the roots are transported to above ground via the xylem in response to plant-microbe interaction and soil nitrogen starvation, respectively. Their leucine-rich repeat transmembrane receptors localized in the shoot phloem are required for relaying the signal from the shoot to the root. These findings well fit to the current scenario of root-to-shoot-to-root feedback signaling, where peptide transport achieves the root-to-shoot signaling, the first half of the signaling process. Meanwhile, it is now well evidenced that proteins and a range of RNAs are transported via the phloem translocation system, and some of those can exert their physiological functions at their destinations, including roots. Thus, plant vascular systems may serve not only as conduits for the translocation of essential substances but also as long-distance communication pathways that allow plants to adapt to changes in internal and external environments at the whole plant level.

  19. Dynamics of long-distance signaling via plant vascular tissues

    Science.gov (United States)

    Notaguchi, Michitaka; Okamoto, Satoru

    2015-01-01

    Plant vascular systems are constructed by specific cell wall modifications through which cells are highly specialized to make conduits for water and nutrients. Xylem vessels are formed by thickened cell walls that remain after programmed cell death, and serve as water conduits from the root to the shoot. In contrast, phloem tissues consist of a complex of living cells, including sieve tube elements and their neighboring companion cells, and translocate photosynthetic assimilates from mature leaves to developing young tissues. Intensive studies on the content of vascular flow fluids have unveiled that plant vascular tissues transport various types of gene product, and the transport of some provides the molecular basis for the long-distance communications. Analysis of xylem sap has demonstrated the presence of proteins in the xylem transpiration stream. Recent studies have revealed that CLE and CEP peptides secreted in the roots are transported to above ground via the xylem in response to plant–microbe interaction and soil nitrogen starvation, respectively. Their leucine-rich repeat transmembrane receptors localized in the shoot phloem are required for relaying the signal from the shoot to the root. These findings well-fit to the current scenario of root-to-shoot-to-root feedback signaling, where peptide transport achieves the root-to-shoot signaling, the first half of the signaling process. Meanwhile, it is now well-evidenced that proteins and a range of RNAs are transported via the phloem translocation system, and some of those can exert their physiological functions at their destinations, including roots. Thus, plant vascular systems may serve not only as conduits for the translocation of essential substances but also as long-distance communication pathways that allow plants to adapt to changes in internal and external environments at the whole plant level. PMID:25852714

  20. Measuring Long-Distance Romantic Relationships: A Validity Study

    Science.gov (United States)

    Pistole, M. Carole; Roberts, Amber

    2011-01-01

    This study investigated aspects of construct validity for the scores of a new long-distance romantic relationship measure. A single-factor structure of the long-distance romantic relationship index emerged, with convergent and discriminant evidence of external validity, high internal consistency reliability, and applied utility of the scores.…

  1. Faroese long-distance reflexives face off against Icelandic long-distance reflexives

    Directory of Open Access Journals (Sweden)

    Tania E. Strahan

    2009-01-01

    Full Text Available Long-distance reflexives (LDRs in Faroese are often compared to those in Icelandic, and are even considered to have the same distribution (Thráinsson et al., 2004. In this paper I evaluate the extent to which this is true. The results from recent fieldwork show that there are clear differences between the LDR in the two closely related languages, in particular that Faroese speakers often reject LDR sentences that contain a non-third person, and that Faroese LDR is often completely acceptable out of a non-complement clause. In addition, initial findings suggest that there may be dialectal variation with respect to at least these two aspects of LDR in Faroese.

  2. Long-distance dispersal by sea-drifted seeds has maintained the global distribution of Ipomoea pes-caprae subsp. brasiliensis (Convolvulaceae).

    Science.gov (United States)

    Miryeganeh, Matin; Takayama, Koji; Tateishi, Yoichi; Kajita, Tadashi

    2014-01-01

    Ipomoea pes-caprae (Convolvulaceae), a pantropical plant with sea-drifted seeds, is found globally in the littoral areas of tropical and subtropical regions. Unusual long-distance seed dispersal has been believed to be responsible for its extraordinarily wide distribution; however, the actual level of inter-population migration has never been studied. To clarify the level of migration among populations of I. pes-caprae across its range, we investigated nucleotide sequence variations by using seven low-copy nuclear markers and 272 samples collected from 34 populations that cover the range of the species. We applied coalescent-based approaches using Bayesian and maximum likelihood methods to assess migration rates, direction of migration, and genetic diversity among five regional populations. Our results showed a high number of migrants among the regional populations of I. pes-caprae subsp. brasiliensis, which suggests that migration among distant populations was maintained by long-distance seed dispersal across its global range. These results also provide strong evidence for recent trans-oceanic seed dispersal by ocean currents in all three oceanic regions. We also found migration crossing the American continents. Although this is an apparent land barrier for sea-dispersal, migration between populations of the East Pacific and West Atlantic regions was high, perhaps because of trans-isthmus migration via pollen dispersal. Therefore, the migration and gene flow among populations across the vast range of I. pes-caprae is maintained not only by seed dispersal by sea-drifted seeds, but also by pollen flow over the American continents. On the other hand, populations of subsp. pes-caprae that are restricted to only the northern part of the Indian Ocean region were highly differentiated from subsp. brasiliensis. Cryptic barriers that prevented migration by sea dispersal between the ranges of the two subspecies and/or historical differentiation that caused local adaptation

  3. Long-distance dispersal by sea-drifted seeds has maintained the global distribution of Ipomoea pes-caprae subsp. brasiliensis (Convolvulaceae.

    Directory of Open Access Journals (Sweden)

    Matin Miryeganeh

    Full Text Available Ipomoea pes-caprae (Convolvulaceae, a pantropical plant with sea-drifted seeds, is found globally in the littoral areas of tropical and subtropical regions. Unusual long-distance seed dispersal has been believed to be responsible for its extraordinarily wide distribution; however, the actual level of inter-population migration has never been studied. To clarify the level of migration among populations of I. pes-caprae across its range, we investigated nucleotide sequence variations by using seven low-copy nuclear markers and 272 samples collected from 34 populations that cover the range of the species. We applied coalescent-based approaches using Bayesian and maximum likelihood methods to assess migration rates, direction of migration, and genetic diversity among five regional populations. Our results showed a high number of migrants among the regional populations of I. pes-caprae subsp. brasiliensis, which suggests that migration among distant populations was maintained by long-distance seed dispersal across its global range. These results also provide strong evidence for recent trans-oceanic seed dispersal by ocean currents in all three oceanic regions. We also found migration crossing the American continents. Although this is an apparent land barrier for sea-dispersal, migration between populations of the East Pacific and West Atlantic regions was high, perhaps because of trans-isthmus migration via pollen dispersal. Therefore, the migration and gene flow among populations across the vast range of I. pes-caprae is maintained not only by seed dispersal by sea-drifted seeds, but also by pollen flow over the American continents. On the other hand, populations of subsp. pes-caprae that are restricted to only the northern part of the Indian Ocean region were highly differentiated from subsp. brasiliensis. Cryptic barriers that prevented migration by sea dispersal between the ranges of the two subspecies and/or historical differentiation that

  4. Testing the Münch hypothesis of long distance phloem transport in plants

    DEFF Research Database (Denmark)

    Knoblauch, Michael; Knoblauch, Jan; Mullendore, Daniel L.

    2016-01-01

    Long distance transport in plants occurs in sieve tubes of the phloem. The pressure flow hypothesis introduced by Ernst Münch in 1930 describes a mechanism of osmotically generated pressure differentials that are supposed to drive the movement of sugars and other solutes in the phloem...

  5. Modelling Gene Flow between Fields of White Clover with Honeybees as Pollen Vectors

    DEFF Research Database (Denmark)

    Løjtnant, Christina; Boelt, Birte; Clausen, Sabine Karin

    2012-01-01

    % with an estimated 95% percentile of 70%. The results show that the European Union threshold limit of 0.9% GM admixture for food and feed will likely be exceeded at times and especially organic farmers that do not accept GM admixture and often have clover and clover–grass fields might face challenges with admixture.......7%, but subjected to large uncertainty. In a worst case scenario with adjacent fields—one with a genetically modified (GM) T. repens cultivar and the other with a conventional T. repens cultivar—and where all arriving bees were expected to transfer GM pollen, the median gene flow was modelled to be 7...

  6. Perniosis in a long-distance cyclist crossing Mongolia.

    Science.gov (United States)

    Neal, Andrew J; Jarman, Alison M; Bennett, Timothy G

    2012-01-01

    We report a case of severe perniosis in a long-distance cyclist. This case demonstrates the importance of identifying those at risk of cold-related injuries who are about to embark on extensive travel in cold environments.

  7. Research for visualization of running state of long-distance water transmission pipeline based on OpenGL

    Science.gov (United States)

    Zhang, Xiaoping; Xu, Xuejun; Liu, Bing; Zhang, Zhendong

    2017-03-01

    The running condition of long distance water pipeline are complicated and changeable, and the lag of water flow is obvious, which is the key technical problem to be solved in the process of regulation and control. According to the present situation of the long-distance water conveyance project, the visualization simulation technology is used to study the operation and management of the long-distance water conveyance pipeline based on OpenGL technology. The system developed in this paper can combine pipeline information, working condition data and relevant data to provide a visualization platform for analysis and decision-making of project management and operation.

  8. High rates of gene flow by pollen and seed in oak populations across Europe.

    Directory of Open Access Journals (Sweden)

    Sophie Gerber

    Full Text Available Gene flow is a key factor in the evolution of species, influencing effective population size, hybridisation and local adaptation. We analysed local gene flow in eight stands of white oak (mostly Quercus petraea and Q. robur, but also Q. pubescens and Q. faginea distributed across Europe. Adult trees within a given area in each stand were exhaustively sampled (range [239, 754], mean 423, mapped, and acorns were collected ([17,147], 51 from several mother trees ([3], [47], 23. Seedlings ([65,387], 178 were harvested and geo-referenced in six of the eight stands. Genetic information was obtained from screening distinct molecular markers spread across the genome, genotyping each tree, acorn or seedling. All samples were thus genotyped at 5-8 nuclear microsatellite loci. Fathers/parents were assigned to acorns and seedlings using likelihood methods. Mating success of male and female parents, pollen and seed dispersal curves, and also hybridisation rates were estimated in each stand and compared on a continental scale. On average, the percentage of the wind-borne pollen from outside the stand was 60%, with large variation among stands (21-88%. Mean seed immigration into the stand was 40%, a high value for oaks that are generally considered to have limited seed dispersal. However, this estimate varied greatly among stands (20-66%. Gene flow was mostly intraspecific, with large variation, as some trees and stands showed particularly high rates of hybridisation. Our results show that mating success was unevenly distributed among trees. The high levels of gene flow suggest that geographically remote oak stands are unlikely to be genetically isolated, questioning the static definition of gene reserves and seed stands.

  9. Human-mediated dispersal of seeds over long distances

    Science.gov (United States)

    Wichmann, Matthias C.; Alexander, Matt J.; Soons, Merel B.; Galsworthy, Stephen; Dunne, Laura; Gould, Robert; Fairfax, Christina; Niggemann, Marc; Hails, Rosie S.; Bullock, James M.

    2008-01-01

    Human activities have fundamental impacts on the distribution of species through altered land use, but also directly by dispersal of propagules. Rare long-distance dispersal events have a disproportionate importance for the spread of species including invasions. While it is widely accepted that humans may act as vectors of long-distance dispersal, there are few studies that quantify this process. We studied in detail a mechanism of human-mediated dispersal (HMD). For two plant species we measured, over a wide range of distances, how many seeds are carried by humans on shoes. While over half of the seeds fell off within 5 m, seeds were regularly still attached to shoes after 5 km. Semi-mechanistic models were fitted, and these suggested that long-distance dispersal on shoes is facilitated by decreasing seed detachment probability with distance. Mechanistic modelling showed that the primary vector, wind, was less important as an agent of long-distance dispersal, dispersing seeds less than 250 m. Full dispersal kernels were derived by combining the models for primary dispersal by wind and secondary dispersal by humans. These suggest that walking humans can disperse seeds to very long distances, up to at least 10 km, and provide some of the first quantified dispersal kernels for HMD. PMID:18826932

  10. Pollen competition as a reproductive isolation barrier represses transgene flow between compatible and co-flowering citrus genotypes.

    Directory of Open Access Journals (Sweden)

    Elsa Pons

    Full Text Available BACKGROUND/OBJECTIVE: Despite potential benefits granted by genetically modified (GM fruit trees, their release and commercialization raises concerns about their potential environmental impact, and the transfer via pollen of transgenes to cross-compatible cultivars is deemed to be the greatest source for environmental exposure. Information compiled from field trials on GM trees is essential to propose measures to minimize the transgene dispersal. We have conducted a field trial of seven consecutive years to investigate the maximum frequency of pollen-mediated crop-to-crop transgene flow in a citrus orchard, and its relation to the genetic, phenological and environmental factors involved. METHODOLOGY/PRINCIPAL FINDINGS: Three different citrus genotypes carrying the uidA (GUS tracer marker gene (pollen donors and a non-GM self-incompatible contiguous citrus genotype (recipient were used in conditions allowing natural entomophilous pollination to occur. The examination of 603 to 2990 seeds per year showed unexpectedly low frequencies (0.17-2.86% of transgene flow. Paternity analyses of the progeny of subsets of recipient plants using 10 microsatellite (SSR loci demonstrated a higher mating competence of trees from another non-GM pollen source population that greatly limited the mating chance of the contiguous cross-compatible and flowering-synchronized transgenic pollen source. This mating superiority could be explained by a much higher pollen competition capacity of the non-GM genotypes, as was confirmed through mixed-hand pollinations. CONCLUSIONS/SIGNIFICANCE: Pollen competition strongly contributed to transgene confinement. Based on this finding, suitable isolation measures are proposed for the first time to prevent transgene outflow between contiguous plantings of citrus types that may be extendible to other entomophilous transgenic fruit tree species.

  11. Comparison of pollen gene flow among four European beech (Fagus sylvatica L.) populations characterized by different management regimes.

    Science.gov (United States)

    Piotti, A; Leonardi, S; Buiteveld, J; Geburek, T; Gerber, S; Kramer, K; Vettori, C; Vendramin, G G

    2012-03-01

    The study of the dispersal capability of a species can provide essential information for the management and conservation of its genetic variability. Comparison of gene flow rates among populations characterized by different management and evolutionary histories allows one to decipher the role of factors such as isolation and tree density on gene movements. We used two paternity analysis approaches and different strategies to handle the possible presence of genotyping errors to obtain robust estimates of pollen flow in four European beech (Fagus sylvatica L.) populations from Austria and France. In each country one of the two plots is located in an unmanaged forest; the other plots are managed with a shelterwood system and inside a colonization area (in Austria and France, respectively). The two paternity analysis approaches provided almost identical estimates of gene flow. In general, we found high pollen immigration (~75% of pollen from outside), with the exception of the plot from a highly isolated forest remnant (~50%). In the two unmanaged plots, the average within-population pollen dispersal distances (from 80 to 184 m) were higher than previously estimated for beech. From the comparison between the Austrian managed and unmanaged plots, that are only 500 m apart, we found no evidence that either gene flow or reproductive success distributions were significantly altered by forest management. The investigated phenotypic traits (crown area, height, diameter and flowering phenology) were not significantly related with male reproductive success. Shelterwood seems to have an effect on the distribution of within-population pollen dispersal distances. In the managed plot, pollen dispersal distances were shorter, possibly because adult tree density is three-fold (163 versus 57 trees per hectare) with respect to the unmanaged one.

  12. Long-distance coherent coupling in a quantum dot array.

    Science.gov (United States)

    Braakman, F R; Barthelemy, P; Reichl, C; Wegscheider, W; Vandersypen, L M K

    2013-06-01

    Controlling long-distance quantum correlations is central to quantum computation and simulation. In quantum dot arrays, experiments so far rely on nearest-neighbour couplings only, and inducing long-distance correlations requires sequential local operations. Here, we show that two distant sites can be tunnel-coupled directly. The coupling is mediated by virtual occupation of an intermediate site, with a strength that is controlled via the energy detuning of this site. It permits a single charge to oscillate coherently between the outer sites of a triple dot array without passing through the middle, as demonstrated through the observation of Landau-Zener-Stückelberg interference. The long-distance coupling significantly improves the prospects of fault-tolerant quantum computation using quantum dot arrays, and opens up new avenues for performing quantum simulations in nanoscale devices.

  13. Cross-ocean GPS long distance rapid static positioning methods

    Directory of Open Access Journals (Sweden)

    Zhang Jie

    2013-02-01

    Full Text Available The method of cross-ocean GPS long distance rapid static positioning has become one of the main technical means of GPS static positioning away from the mainland. The key technology had been analyzed including data preprocessing and quality control, long distance integer ambiguity resolution and static Kalman filter parameter estimation. Effective data processing method of cross-ocean GPS long baseline rapid static positioning had been proposed. Through the analysis of practical examples of coastal and ocean, the feasibility of cross-ocean GPS long distance rapid static positioning based on the method is testified and verified. The results show that the accuracy of one-hour single baseline static positioning for the 500–600 km distance can be better than 10 cm in the three-dimensional coordinates, which can suffice static positioning accuracy in the special ocean environment.

  14. Long distance runners present upregulated sweating responses than sedentary counterparts.

    Directory of Open Access Journals (Sweden)

    Jeong-Beom Lee

    Full Text Available Relatively few studies have investigated peripheral sweating mechanisms of long-distance runners. The aim of this study was to compare peripheral sweating mechanisms in male long-distance runners, and sedentary counterparts. Thirty six subjects, including 20 sedentary controls and 16 long-distance runners (with 7-12 years of athletic training, average 9.2±2.1 years were observed. Quantitative sudomotor axon reflex testing (QSART with iontophoresis (2 mA for 5 min and 10% acetylcholine (ACh were performed to determine axon reflex-mediated and directly activated (DIR, muscarinic receptor sweating. Sweat onset time, sweat rate, number of activated sweat glands, sweat output per gland and skin temperature were measured at rest while maximum oxygen uptake (VO2max were measured during maximal cycling. Sweat rate, activated sweat glands, sweat output per gland, skin temperature and VO2max were significantly higher in the trained runners than in the sedentary controls. Sweat onset time was significantly shorter for the runners. In the group of long-distance runners, significant correlations were found between VO2max and sweat onset time (r2 = 0.543, P<0.01, n = 16, DIR sweat rate (r2 = 0.584, P<0.001, n = 16, sweat output per gland (r2 = 0.539, P<0.01, n = 16. There was no correlation between VO2max and activated sweat glands. These findings suggest that habitual long-distance running results in upregulation of the peripheral sweating mechanisms in humans. Additional research is needed to determine the molecular mechanism underlying these changes. These findings complement the existing sweating data in long-distance runners.

  15. Generation of Long-Distance Entanglement in Spin System

    Institute of Scientific and Technical Information of China (English)

    XI Xiao-Qiang; LIU Wu-Ming

    2008-01-01

    We propose two schemes to produce long-distance entanglement in a spin chain. The first is based on a controllable interaction system, one starts from an entangled kernel and adds weaken interaction spins to the boundary sites step by step, then the entanglement will be extended longer and longer and its value is equal to that of its kernel. The second is based on a uniform interaction (J) system with a bulk magnetic field (B) that is absent for the boundary qubits, as long as B/J>5, one can obtain near perfect long distance entanglement. Ultra-low-temperature is needed in both schemes.

  16. Long-distance signaling of iron deficiency in plants

    OpenAIRE

    2008-01-01

    In a recent issue of the Planta, we established two points regarding the long-distance signal of iron status in tobacco (Nicotiana tabacum L.). One is that the long-distance signal generated in iron deficient tissues is a major factor in positively regulating the expressions of iron uptake genes in tobacco. The expression of a ferric chelate reductase gene (NtFRO1) and an iron-regulated transporter gene (NtIRT1) in roots decreased by cutting off the leaves grown under the iron-deficient condi...

  17. Simulation of the Movement of Long-distance AUV

    Institute of Scientific and Technical Information of China (English)

    DU Xiao-xu; SONG Bao-wei; HU Hai-bao; SHAO Cheng

    2007-01-01

    In order to study the movement of the long-distance torpedo-like autonomous underwater vehicle (AUV) which is controlled by the dynamic positioning system (DPS), by adopting momentum theorem and the angular momentum theorem, the appropriate movement math model for the long-distance torpedo-like AUV has been built and the thrust of DPS is distributed. Several representative movements of AUV are simulated, such as transferring between two random points and pointing circumrotation movement. The simulation result is analyzed. It shows that DPS including five thrusters can control the AUV movement steadily at low velocity.

  18. Evaluation of Macrobend Loss on Long Distance Optical Ground Wire

    Directory of Open Access Journals (Sweden)

    M. F. M. Salleh

    2015-06-01

    Full Text Available Bend loss is a kind of loss that contributes to the power attenuation which is caused by the bending of optical fiber. For long distance optical fiber, bending might occur at joining point as there are many joining points along the link. Studies related to bend loss always relate the effect of bend radius on bend loss value. There is no study that relates the value of loss that can be affected by other factors like the natural environmental conditions. In this study, the evaluation of bend loss on existing long distance Optical Ground Wire (OPGW was studied since the cable was exposed to any climate condition.

  19. Pollination of pima pineapple cactus (Coryphantha sheeri var. robustispina): does pollen flow limit abundance of this endangered species?

    Science.gov (United States)

    Christopher J. McDonald; Guy R. McPherson

    2005-01-01

    Pima pineapple cactus (PPC) (Coryphantha sheeri var. robustispina), a federally listed endangered species, occurs throughout southeastern Arizona and has relatively low population densities. To determine whether pollination limits reproduction of PPC we used florescent dye to quantify pollen flow between individuals in a PPC...

  20. EVIDENCE FOR LANDSCAPE LEVEL, POLLEN-MEDIATED GENE FLOW FROM CREEPING BENTGRASS WITH CP4 EPSPS AS A MARKER

    Science.gov (United States)

    In a landscape level study, gene flow via pollen was tracked from multiple source fields of genetically modified (GM) herbicide resistant creeping bentgrass (Agrostis stolonifera L.) to 75 of 138 sentinel plants of A. stolonifera and to 29 of 69 resident populations of Agrostis s...

  1. Plantar pressure changes after long-distance walking.

    NARCIS (Netherlands)

    Stolwijk, N.M.; Duysens, J.E.J.; Louwerens, J.W.; Keijsers, N.L.

    2010-01-01

    PURPOSE: The popularity of long-distance walking (LDW) has increased in the last decades. However, the effects of LDW on plantar pressure distribution and foot complaints, in particular, after several days of walking, have not been studied. METHODS: We obtained the plantar pressure data of 62

  2. (Non-)Arguments in Long-Distance Extractions

    DEFF Research Database (Denmark)

    Nyvad, Anne Mette; Kizach, Johannes; Christensen, Ken Ramshøj

    2015-01-01

    Previous research has shown that in fully grammatical sentences, response time increases and acceptability decreases when the filler in a long-distance extraction is incom- patible with the matrix verb. This effect could potentially be due to a difference between argument and adjunct extraction...

  3. Acceptability and processing of long-distance dependencies in Danish

    DEFF Research Database (Denmark)

    Poulsen, Mads

    2008-01-01

    Long-distance dependencies have been the object of much theoretical interest in the Scandinavian languages and in general, but the empirical foundation for theorizing has been limited. The present paper investigates extraction from complement and adverbial clauses in Danish using acceptability...

  4. (Non-)Arguments in Long-Distance Extractions

    DEFF Research Database (Denmark)

    Nyvad, Anne Mette; Kizach, Johannes; Christensen, Ken Ramshøj

    2015-01-01

    Previous research has shown that in fully grammatical sentences, response time increases and acceptability decreases when the filler in a long-distance extraction is incom- patible with the matrix verb. This effect could potentially be due to a difference between argument and adjunct extraction...

  5. Psycho-Social Parameters in Young Female Long Distance Runners.

    Science.gov (United States)

    Burke, Edmund J.; And Others

    This study was designed to determine selected psycho-social parameters associated with a group of teenage, female long distance runners. These young women, who train by running approximately 50-90 miles per week, had scores in certain physiological and anthropometric measurements which were among the most advantageous for running ever recorded in…

  6. 47 CFR 32.5100 - Long distance message revenue.

    Science.gov (United States)

    2010-10-01

    ... (multipoint-to-point service). These calls require the use of dedicated access lines connecting a subscriber's... generally initiated by the subscriber's customer or correspondent. (b) Long distance services which permit..., supervisory control, miscellaneous signaling and channels furnished for the purpose of extending customer...

  7. UNDERSTANDING THE POPULATION GENETIC STRUCTURE OF GLEDITSIA TRIACANTHOS L.: THE SCALE AND PATTERN OF POLLEN GENE FLOW.

    Science.gov (United States)

    Schnabel, Andrew; Hamrick, J L

    1995-10-01

    Spatial and temporal patterns of gene flow determine the extent to which populations can differentiate from one another as a result of natural selection or genetic drift. In this study, we investigated pollen-mediated gene flow in two eastern Kansas populations of the subdioecious tree species, Gleditsia triacanthos L. (Leguminosae), or honeylocust. In 2 yr at each site, we used paternity-exclusion analysis to estimate the proportion of seeds sired by immigrant pollen. We also used a single-parent and parent-pair exclusion analysis on naturally established seedlings and saplings to estimate gene flow into one site over a 12-yr period and into the second site over a 22-yr period. Results of both analyses showed high minimum estimates of pollen gene flow into each site (17%-30%). In each population, we found significantly less gene flow in years of high fruit production than in years of low fruit production, but in one population, we observed little variation in gene-flow rates among age classes of seedlings and saplings. The level of pollen gene flow showed weak negative dependence on the relative isolation distances of the maternal trees sampled (140-240 m at one site vs. 85-120 m at the second site), and gene-flow estimates from naturally established juveniles were very similar at the two sites. Within populations, a multiple regression model showed that maximum-likelihood estimates of male fertility were negatively associated with distances between mates and positively associated with male size as measured by stem diameter. In neither population, however, did the regression explain more than 16% of the total variation in male fertilities. © 1995 The Society for the Study of Evolution.

  8. Long-distance impact of Iceland plume on Norway's rifted margin.

    Science.gov (United States)

    Koptev, Alexander; Cloetingh, Sierd; Burov, Evgueni; François, Thomas; Gerya, Taras

    2017-09-04

    Results of a 3D modeling study inspired by recent seismic tomography of the Northern Atlantic mantle suggest that a complex pattern of hot mantle distribution with long horizontal flows originating from the Iceland mantle plume has been the norm in the geological past. In the Northern Atlantic the Iceland plume has a strong long-distance impact on intraplate deformation affecting both onshore and offshore parts of Norway's rifted margin. As a result, this margin is characterized by large magnitude differential topography sustained over at least several tens of Myr. Here we use high-resolution 3D thermo-mechanical modeling to demonstrate that the long-distance plume impact can be explained by its fast lateral propagation controlled by pre-existing lithosphere structures. Numerical models show that these structures strongly affect the style of horizontal flow of plume head material. This results in long-distance propagation of hot material emplaced at the lithosphere-asthenosphere boundary causing long-wavelength anomalies in onshore topography of Norway's rifted margin. Short-wavelength offshore topographic domes are likely caused by joint occurrence of plume-related thermal perturbations and gravitational forces related to plate thickening (ridge push). Our 3D modeling brings together plume impingement, spreading ridge dynamics, and the formation of anomalous intraplate structures offshore Norway in one scenario.

  9. Passive phloem loading and long-distance transport in a synthetic tree-on-a-chip

    DEFF Research Database (Denmark)

    Comtet, Jean; Jensen, Kaare Hartvig; Turgeon, Robert

    2017-01-01

    Vascular plants rely on differences in osmotic pressure to export sugars from regions of synthesis (mature leaves) to sugar sinks (roots, fruits). In this process, known as Münch pressure flow, the loading of sugars from photosynthetic cells to the export conduit (the phloem) is crucial, as it sets...... the pressure head necessary to power long-distance transport. Whereas most herbaceous plants use active mechanisms to increase phloem sugar concentration above that of the photosynthetic cells, in most tree species, for which transport distances are largest, loading seems, counterintuitively, to occur by means...... of passive symplastic diffusion from the mesophyll to the phloem. Here, we use a synthetic microfluidic model of a passive loader to explore the non-linear dynamics that arise during export and determine the ability of passive loading to drive long-distance transport. We first demonstrate that in our device...

  10. Model-based calculating tool for pollen-mediated gene flow frequencies in plants.

    Science.gov (United States)

    Lei, Wang; Bao-Rong, Lu

    2016-12-30

    The potential social-economic and environmental impacts caused by transgene flow from genetically engineered (GE) crops have stimulated worldwide biosafety concerns. To determine transgene flow frequencies resulted from pollination is the first critical step for assessing such impacts, in addition to the determination of transgene expression and fitness in crop-wild hybrid descendants. Two methods are commonly used to estimate pollen-mediated gene flow (PMGF) frequencies: field experimenting and mathematical modeling. Field experiments can provide relatively accurate results but are time/resource consuming. Modeling offers an effective complement for PMGF experimental assessment. However, many published models describe PMGF by mathematical equations and are practically not easy to use. To increase the application of PMGF modeling for the estimation of transgene flow, we established a tool to calculate PMGF frequencies based on a quasi-mechanistic PMGF model for wind-pollination species. This tool includes a calculating program displayed by an easy-operating interface. PMGF frequencies of different plant species can be quickly calculated under different environmental conditions by including a number of biological and wind speed parameters that can be measured in the fields/laboratories or obtained from published data. The tool is freely available in the public domain (http://ecology.fudan.edu.cn/userfiles/cn/files/Tool_Manual.zip). Case studies including rice, wheat, and maize demonstrated similar results between the calculated frequencies based on this tool and those from published PMGF data. This PMGF calculating tool will provide useful information for assessing and monitoring social-economic and environmental impacts caused by transgene flow from GE crops. This tool can also be applied to determine the isolation distances between GE and non-GE crops in a coexistence agro-ecosystem, and to ensure the purity of certified seeds by setting proper isolation distances

  11. Pollen-mediated gene flow and seed exchange in small-scale Zambian maize farming, implications for biosafety assessment

    Science.gov (United States)

    Bøhn, Thomas; Aheto, Denis W.; Mwangala, Felix S.; Fischer, Klara; Bones, Inger Louise; Simoloka, Christopher; Mbeule, Ireen; Schmidt, Gunther; Breckling, Broder

    2016-10-01

    Gene flow in agricultural crops is important for risk assessment of genetically modified (GM) crops, particularly in countries with a large informal agricultural sector of subsistence cultivation. We present a pollen flow model for maize (Zea mays), a major staple crop in Africa. We use spatial properties of fields (size, position) in three small-scale maize farming communities in Zambia and estimate rates of cross-fertilisation between fields sown with different maize varieties (e.g. conventional and transgene). As an additional factor contributing to gene flow, we present data on seed saving and sharing among farmers that live in the same communities. Our results show that: i) maize fields were small and located in immediate vicinity of neighboring fields; ii) a majority of farmers saved and shared seed; iii) modeled rates of pollen-mediated gene flow showed extensive mixing of germplasm between fields and farms and iv) as a result, segregation of GM and non-GM varieties is not likely to be an option in these systems. We conclude that the overall genetic composition of maize, in this and similar agricultural contexts, will be strongly influenced both by self-organised ecological factors (pollen flow), and by socially mediated intervention (seed recycling and sharing).

  12. A long-distance travel demand model for Europe

    DEFF Research Database (Denmark)

    Rich, Jeppe; Mabit, Stefan Lindhard

    2012-01-01

    of different level-of-service variables. The results suggest that the perception of both travel time and cost varies with journey length in a non-linear way. For car drivers and car passengers, elasticities increase with the length of the journey, whereas the opposite is true for rail, bus, and air passengers......In Europe, approximately 50% of all passenger kilometres come from trips beyond 100 km according to matrices developed in the TRANSTOOLS project. This accounts for an even larger share of CO2 emissions due to a higher modal share of air transport. Therefore long-distance trips are increasingly...... relevant from a political and environmental point of view. The paper presents the first tour-based long-distance travel demand model for passenger trips in and between 42 European countries. The model is part of a new European transport model developed for the European Commission, the TRANSTOOLS II model...

  13. Turning points in long distance grandparent-grandchild relationships.

    Science.gov (United States)

    Bangerter, Lauren R; Waldron, Vincent R

    2014-04-01

    This study examines changes in long-distance relationships between grandparents and their adolescent grandchildren by identifying relational turning points and trajectories. Qualitative analysis of data collected from interviews with grandparents yielded 100 unique turning points. Constant comparative analysis revealed eight distinct categories of relational turning points; Spending Time Together, Family Relational Dynamics, Geographic Distance, Lack of Relational Investment, Use of Technology, Relational Investment, Lack of Free Time, and Grandchild Gaining Independence. These varied in the degree to which they positively or negatively impacted relational closeness. Application of the Retrospective Interview Technique (RIT) yielded five distinctive relational trajectories: Decrease in Closeness, Increase in Closeness, Multidimensional Changes in Closeness, Minimal Changes in Closeness, and Consistent Relational Closeness. The results expose the communicative challenges faced by long-distance-grandparents, the diversity of these relationships, and the ways in which grandparenting bonds change over time. Implications for an enriched understanding of grandparenting relationships and practical applications for families are explored.

  14. Long-distance propagation of forces in a cell.

    Science.gov (United States)

    Wang, Ning; Suo, Zhigang

    2005-03-25

    A fundamental question in the field of mechanotransduction is how forces propagate inside a cell. Recent experiments have shown that a force of a physiological magnitude, applied via a focal adhesion, can propagate a long distance into the cell. This observation disagrees with existing models that regard the cell as a homogeneous body. We show that this "action at a distance" results from the inhomogeneity in the cell: a prestressed and stiff actin bundle guides the propagation of forces over long distances. Our models highlight the enormous ratios of the prestress and the modulus of the actin bundle to the modulus of the cytoskeleton network. For a normal cell, the models predict that forces propagate over characteristic lengths comparable to the size of the cell. The characteristic lengths can be altered, however, by treatments of the cell. We provide experimental evidence and discuss biological implications.

  15. Exploring characteristics and motives of long distance commuter cyclists

    DEFF Research Database (Denmark)

    Hansen, Karsten Bruun; Sick Nielsen, Thomas

    2014-01-01

    , commuter cyclists (45 km from home to work) have more mobility options, higher incomes, and a longer education than other commuter cyclists. The main motive for longer distance cycling is physical exercise, followed by reduced costs and time used for traveling. The long distance commuter cyclists surveyed......Longer distance cycling is a commuting mode that contributes to sustainability and public health objectives, but little is known about current long distance cyclist's motives. The paper explores longer distance commuter cyclists, their characteristics, practice and motives. Longer distance...... are very positive about their commute - pointing to positive experiences, better mood, and stress relief as experiences related to their cycle trip to work. Policy support should devote attention to unlocking the potential that may be embedded in individuals combining their exercise and travel time...

  16. Historical perspectives on long distance transport of animals

    Directory of Open Access Journals (Sweden)

    Jean Blancou

    2008-03-01

    Full Text Available Since Roman Antiquity, domestic and wild animals have been transported over long distances for purposes as different as improvement of livestock production, food supply, scientific interest, public entertainment, war and numerous other purposes. This long distance transportation was originally limited to the Mediterranean area but, during the Middle Ages extended to the rest of Europe. The conquest of the New World was the first major occasion to transport large numbers of horses and other livestock across the oceans. Domestic animals were necessary for the new colonies and their armies. European expansion to Asia and the Pacific also required the transportation of large numbers of domestic animals. Data, figures and description of the conditions of transport of animals as different as wild beasts, horses, camels, elephants or poultry are reported for each historical period.

  17. WELFARE ASPECTS OF THE LONG DISTANCE TRANSPORTATION OF CATTLE

    Directory of Open Access Journals (Sweden)

    EVANGELIA N. SOSSIDOU

    2013-07-01

    Full Text Available This paper sets out to examine the facts behind the trade of long distance transportation of cattle. In particular it looks at the various welfare implications during handling and transport with examples from research work on cattle. The role of the science is explained and the methodology for assessing the welfare of animals is then presented. Finally, public concerns and legal position are presented as they play an important role to promote farm animal welfare principles during transportation.

  18. Microbial modification of host long-distance dispersal capacity

    OpenAIRE

    Hutchings Linda; Bonte Dries; Martin Oliver Y; Goodacre Sara L; Woolley Chris; Ibrahim Kamal; George Thomas CF; Hewitt Godfrey M

    2009-01-01

    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 recoloni...

  19. Long distance atomic teleportation with as good success as desired

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Manoj K., E-mail: manoj.qit@gmail.com [Physics Department, University of Allahabad (India); Space Applications Centre, Indian Space Research Organization (ISRO), Ahmedabad (India); Prakash, Hari [Physics Department, University of Allahabad (India); Indian Institute of Information Technology, Allahabad (India)

    2015-09-15

    Long distance atomic teleportation (LDAT) is of prime importance in long distance quantum communication. Scheme proposed by Bose et al. (1999) in principle enables us to have LDAT using cavity decay. However it gives message state dependent fidelity and success rate. Here, using interaction of entangled coherent states with atom–cavity systems and a two-step measurement, we show how, LDAT can be achieved with unit fidelity and as good success as desired under ideal conditions. The scheme is unique in that, the first measurement predicts success or failure. If success is predicted then second measurement gives perfect teleportation. If failure is predicted the message-qubit remains conserved therefore a second attempt may be started. We found that even in presence of decoherence due to dissipation of energy our scheme gives message state independent success rate and almost perfect teleportation in single attempt with mean fidelity of teleportation equal to 0.9 at long distances. However if first attempt fails, unlike ideal case where message-qubit remains conserved with unit fidelity, in presence of decoherence the message-qubit remains conserved to some degree, therefore mean fidelity of teleportation can be increased beyond 0.9 by repeating the process.

  20. Spatial and temporal assessment of pollen- and seed-mediated gene flow from genetically engineered plum Prunus domestica.

    Science.gov (United States)

    Scorza, Ralph; Kriss, Alissa B; Callahan, Ann M; Webb, Kevin; Demuth, Mark; Gottwald, Tim

    2013-01-01

    Pollen flow from a 0.46 ha plot of genetically engineered (GE) Prunus domestica located in West Virginia, USA was evaluated from 2000-2010. Sentinel plum trees were planted at distances ranging from 132 to 854 m from the center of the GE orchard. Plots of mixed plum varieties and seedlings were located at 384, 484 and 998 m from the GE plot. Bee hives (Apis mellifera) were dispersed between the GE plum plot and the pollen flow monitoring sites. Pollen-mediated gene flow from out of the GE plum plot to non-GE plums under the study conditions was low, only occurring at all in 4 of 11 years and then in only 0.31% of the 12,116 seeds analyzed. When it occurred, gene flow, calculated as the number of GUS positive embryos/total embryos sampled, ranged from 0.215% at 132 m from the center of the GE plum plot (28 m from the nearest GE plum tree) to 0.033-0.017% at longer distances (384-998 m). Based on the percentage of GUS positive seeds per individual sampled tree the range was 0.4% to 12%. Within the GE field plot, gene flow ranged from 4.9 to 39%. Gene flow was related to distance and environmental conditions. A single year sample from a sentinel plot 132 m from the center of the GE plot accounted for 65% of the total 11-year gene flow. Spatial modeling indicated that gene flow dramatically decreased at distances over 400 m from the GE plot. Air temperature and rainfall were, respectively, positively and negatively correlated with gene flow, reflecting the effects of weather conditions on insect pollinator activity. Seed-mediated gene flow was not detected. These results support the feasibility of coexistence of GE and non-GE plum orchards.

  1. Spatial and temporal assessment of pollen- and seed-mediated gene flow from genetically engineered plum Prunus domestica.

    Directory of Open Access Journals (Sweden)

    Ralph Scorza

    Full Text Available Pollen flow from a 0.46 ha plot of genetically engineered (GE Prunus domestica located in West Virginia, USA was evaluated from 2000-2010. Sentinel plum trees were planted at distances ranging from 132 to 854 m from the center of the GE orchard. Plots of mixed plum varieties and seedlings were located at 384, 484 and 998 m from the GE plot. Bee hives (Apis mellifera were dispersed between the GE plum plot and the pollen flow monitoring sites. Pollen-mediated gene flow from out of the GE plum plot to non-GE plums under the study conditions was low, only occurring at all in 4 of 11 years and then in only 0.31% of the 12,116 seeds analyzed. When it occurred, gene flow, calculated as the number of GUS positive embryos/total embryos sampled, ranged from 0.215% at 132 m from the center of the GE plum plot (28 m from the nearest GE plum tree to 0.033-0.017% at longer distances (384-998 m. Based on the percentage of GUS positive seeds per individual sampled tree the range was 0.4% to 12%. Within the GE field plot, gene flow ranged from 4.9 to 39%. Gene flow was related to distance and environmental conditions. A single year sample from a sentinel plot 132 m from the center of the GE plot accounted for 65% of the total 11-year gene flow. Spatial modeling indicated that gene flow dramatically decreased at distances over 400 m from the GE plot. Air temperature and rainfall were, respectively, positively and negatively correlated with gene flow, reflecting the effects of weather conditions on insect pollinator activity. Seed-mediated gene flow was not detected. These results support the feasibility of coexistence of GE and non-GE plum orchards.

  2. 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

  3. DETECTION OF POLLEN FLOW IN THE SEEDLING SEED ORCHARD OF Acacia mangium USING DNA MARKER

    Directory of Open Access Journals (Sweden)

    Vivi Yuskianti

    2013-06-01

    Full Text Available Pollen pattern dispersal in seedling seed orchard (SSO is an essential part of a tree-improvement program. Two SSOs of Acacia mangium in South Kalimantan and South Sumatra that represent similar resources in different environments were used in this study.  Genotypes of all trees and seeds from a subset of 10 mother trees in each orchard were determined for 12 microsatellite loci, and parentage analysis was carried out. The results shows that the pollen dispersal pattern in both SSOs decrease with distance from mother tree. Patterns of pollen dispersal, dispersal distance and cumulative frequency of pollen dispersal distance were similar in both SSOs. Random pollen dispersal were found in both SSOs. About 80% of all crosses were found within a 40-m distance range with the most frequent pollination distance between mother tree and male male parents was 0-10 m. No self-pollinated seed was detected. Application of all these aspects found in this study such as random pollen dispersal and the effective pollen dispersal distance can be useful for establishing seedling seed orchard, clonal seed orchard and in other tree improvement activities of A. mangium.

  4. Humans as long-distance dispersers of rural plant communities.

    Directory of Open Access Journals (Sweden)

    Alistair G Auffret

    Full Text Available Humans are known for their capacity to disperse organisms long distances. Long-distance dispersal can be important for species threatened by habitat destruction, but research into human-mediated dispersal is often focused upon few and/or invasive species. Here we use citizen science to identify the capacity for humans to disperse seeds on their clothes and footwear from a known species pool in a valuable habitat, allowing for an assessment of the fraction and types of species dispersed by humans in an alternative context. We collected material from volunteers cutting 48 species-rich meadows throughout Sweden. We counted 24,354 seeds of 197 species, representing 34% of the available species pool, including several rare and protected species. However, 71 species (36% are considered invasive elsewhere in the world. Trait analysis showed that seeds with hooks or other appendages were more likely to be dispersed by humans, as well as those with a persistent seed bank. More activity in a meadow resulted in more dispersal, both in terms of species and representation of the source communities. Average potential dispersal distances were measured at 13 km. We consider humans capable seed dispersers, transporting a significant proportion of the plant communities in which they are active, just like more traditional vectors such as livestock. When rural populations were larger, people might have been regular and effective seed dispersers, and the net rural-urban migration resulting in a reduction in humans in the landscape may have exacerbated the dispersal failure evident in declining plant populations today. With the fragmentation of habitat and changes in land use resulting from agricultural change, and the increased mobility of humans worldwide, the dispersal role of humans may have shifted from providers of regular local and landscape dispersal to providers of much rarer long-distance and regional dispersal, and international invasion.

  5. Detection of changes in the nuclear phase and evaluation of male germ units by flow cytometry during in vitro pollen tube growth in Alstroemeria aurea.

    Science.gov (United States)

    Hirano, Tomonari; Hoshino, Yoichiro

    2009-03-01

    This study aimed to analyze male gamete behavior from mature pollen to pollen tube growth in the bicellular pollen species Alstroemeria aurea. For mature pollen, pollen protoplasts were examined using flow cytometry. The protoplasts showed two peaks of DNA content at 1C and 1.90C. Flow cytometry at different developmental stages of pollen tubes cultured in vitro revealed changes in the nuclear phase at 9 and 18 h after culture. Sperm cell formation occurred at 6-9 h after culture, indicating that the first change was due to the division of the generative cells into sperm cells. After sperm cell formation, the number of vegetative nucleus associations with sperm cells showed a tendency to increase. This association was suggested as the male germ unit (MGU). When sperm cells, vegetative nuclei, and partial MGUs were collected separately from pollen tubes cultured for 18 h and analyzed using a flow cytometer, the sperm cells and vegetative nuclei contained 1C DNA, while the DNA content of partial MGUs was counted as 2C. Therefore, the second change in the nuclear phase, which results in an increase in 2C nuclei, is possibly related to the formation of MGUs.

  6. Long distance transmission through distributed erbium-doped fibers

    DEFF Research Database (Denmark)

    Rottwitt, Karsten; Povlsen, Jørn Hedegaard; Bjarklev, Anders Overgaard

    1993-01-01

    High bit rate, all-optical long-distance transmission could be created through the combined use of loss-compensating gain in erbium-doped fibers and solitons. A detailed analysis of the distributed erbium-doped fiber, including the spectral-gain dependency, is combined with an optimum design...... of the transmission fiber and general bit-error-rate calculations. Changes in wavenumber, group velocity, and fiber dispersion due to erbium doping in a single-mode fiber are evaluated, and a reduction in bit-error rates due to the erbium spectral-gain profile is shown. Transmission through distributed erbium...

  7. Generation of distributed W-states over long distances

    Science.gov (United States)

    Li, Yi

    2017-08-01

    Ultra-secure quantum communication between distant locations requires distributed entangled states between nodes. Various methodologies have been proposed to tackle this technological challenge, of which the so-called DLCZ protocol is the most promising and widely adopted scheme. This paper aims to extend this well-known protocol to a multi-node setting where the entangled W-state is generated between nodes over long distances. The generation of multipartite W-states is the foundation of quantum networks, paving the way for quantum communication and distributed quantum computation.

  8. Long distance part of $\\epsilon_K$ from lattice QCD

    CERN Document Server

    Bai, Ziyuan

    2016-01-01

    We demonstrate the lattice QCD calculation of the long distance contribution to $\\epsilon_K$. Due to the singular, short-distance structure of $\\epsilon_K$, we must perform a short-distance subtraction and introduce a corresponding low-energy constant determined from perturbation theory, which we calculate at Next Leading Order (NLO). We perform the calculation on a $24^3 \\times 64$ lattice with a pion mass of 329 MeV. This work is a complete calculation, which includes all connected and disconnected diagrams.

  9. Using seed purity data to estimate an average pollen mediated gene flow from crops to wild relatives.

    Science.gov (United States)

    Lavigne, C; Klein, E K; Couvet, D

    2002-01-01

    Gene flow from crops to wild related species has been recently under focus in risk-assessment studies of the ecological consequences of growing transgenic crops. However, experimental studies addressing this question are usually temporally or spatially limited. Indirect population-structure approaches can provide more global estimates of gene flow, but their assumptions appear inappropriate in an agricultural context. In an attempt to help the committees providing advice on the release of transgenic crops, we present a new method to estimate the quantity of genes migrating from crops to populations of related wild plants by way of pollen dispersal. This method provides an average estimate at a landscape level. Its originality is based on the measure of the inverse gene flow, i.e. gene flow from the wild plants to the crop. Such gene flow results in an observed level of impurities from wild plants in crop seeds. This level of impurity is usually known by the seed producers and, in any case, its measure is easier than a direct screen of wild populations because crop seeds are abundant and their genetic profile is known. By assuming that wild and cultivated plants have a similar individual pollen dispersal function, we infer the level of pollen-mediated gene flow from a crop to the surrounding wild populations from this observed level of impurity. We present an example for sugar beet data. Results suggest that under conditions of seed production in France (isolation distance of 1,000 m) wild beets produce high numbers of seeds fathered by cultivated plants.

  10. CHARACTERIZATION OF THE MAIZE POLLEN TRANSCRIPTOME

    Science.gov (United States)

    Pollen is a primary vehicle for transgene flow from engineered plants to their non-transgenic, native or weedy relatives. Hence, gene flow will be affected by pollen fitness (e.g., how well a particular pollen grain can outcompete other pollen present on the stigma and complete ...

  11. Effects of Long Distance Transportation on Honey Bee Physiology

    Directory of Open Access Journals (Sweden)

    Kiheung Ahn

    2012-01-01

    Full Text Available Despite the requirement of long distance transportation of honey bees used for pollination, we understand little how transportation affects honey bees. Three trials in three different states (CA, GA, and MI were conducted to study the effects of long distance transportation on honey bee physiology. Newly emerged bees from one colony were split into two groups and introduced into a transported (T colony or a stationary (S colony in each trial. Volumes of hypopharyngeal gland acini in T colonies were significantly smaller than S colonies in all three trials. There were no significant differences between S and T colonies in juvenile hormone titers. Protein content in head showed no significant differences between S and T either in 7-day-old or 17-day-old bees of MI trial, but GA trial showed a significant reduction in bees experiencing transportation. Protein content in thorax was only measured in GA trial and was not significantly different between the two groups. Lipid content in abdomen was not significantly different between the S and T colonies in all three trials. This study suggests that bees experiencing transportation have trouble fully developing their food glands and this might affect their ability to nurse the next generation of workers.

  12. Mechanisms of long-distance dispersal of seeds by wind

    Science.gov (United States)

    Nathan, Ran; Katul, Gabriel G.; Horn, Henry S.; Thomas, Suvi M.; Oren, Ram; Avissar, Roni; Pacala, Stephen W.; Levin, Simon A.

    2002-07-01

    Long-distance dispersal (LDD) is central to species expansion following climate change, re-colonization of disturbed areas and control of pests. The current paradigm is that the frequency and spatial extent of LDD events are extremely difficult to predict. Here we show that mechanistic models coupling seed release and aerodynamics with turbulent transport processes provide accurate probabilistic descriptions of LDD of seeds by wind. The proposed model reliably predicts the vertical distribution of dispersed seeds of five tree species observed along a 45-m high tower in an eastern US deciduous forest. Simulations show that uplifting above the forest canopy is necessary and sufficient for LDD, hence, they provide the means to define LDD quantitatively rather than arbitrarily. Seed uplifting probability thus sets an upper bound on the probability of long-distance colonization. Uplifted yellow poplar seeds are on average lighter than seeds at the forest floor, but also include the heaviest seeds. Because uplifting probabilities are appreciable (as much as 1-5%), and tree seed crops are commonly massive, some LDD events will establish individuals that can critically affect plant dynamics on large scales.

  13. Metal species involved in long distance metal transport in plants

    Science.gov (United States)

    Álvarez-Fernández, Ana; Díaz-Benito, Pablo; Abadía, Anunciación; López-Millán, Ana-Flor; Abadía, Javier

    2014-01-01

    The mechanisms plants use to transport metals from roots to shoots are not completely understood. It has long been proposed that organic molecules participate in metal translocation within the plant. However, until recently the identity of the complexes involved in the long-distance transport of metals could only be inferred by using indirect methods, such as analyzing separately the concentrations of metals and putative ligands and then using in silico chemical speciation software to predict metal species. Molecular biology approaches also have provided a breadth of information about putative metal ligands and metal complexes occurring in plant fluids. The new advances in analytical techniques based on mass spectrometry and the increased use of synchrotron X-ray spectroscopy have allowed for the identification of some metal-ligand species in plant fluids such as the xylem and phloem saps. Also, some proteins present in plant fluids can bind metals and a few studies have explored this possibility. This study reviews the analytical challenges researchers have to face to understand long-distance metal transport in plants as well as the recent advances in the identification of the ligand and metal-ligand complexes in plant fluids. PMID:24723928

  14. Long distance contribution to the KL-KS mass difference

    CERN Document Server

    Christ, N H; Sachrajda, C T; Soni, A; Yu, J

    2012-01-01

    We develop and demonstrate techniques needed to compute the long distance contribution to the $K_{L}$-$K_{S}$ mass difference, $\\Delta M_K$, in lattice QCD and carry out a first, exploratory calculation of this fundamental quantity. The calculation is performed on 2+1 flavor, domain wall fermion, $16^3\\times32$ configurations with a 421 MeV pion mass. We include only current-current operators and drop all disconnected and double penguin diagrams. The short distance part of the mass difference in a 2+1 flavor calculation contains a quadratic divergence cut off by the lattice spacing. Here, this quadratic divergence is eliminated through the GIM mechanism by introducing a valence charm quark. The inclusion of the charm quark makes the complete calculation accessible to lattice methods provided the discretization errors associated with the charm quark can be controlled. The long distance effects are discussed for each parity channel separately. While we can see a clear signal in the parity odd channel, the signa...

  15. Long-distance transport of signals during symbiosis

    Science.gov (United States)

    Xie, Zhi-Ping; Illana, Antonio

    2011-01-01

    Legumes enter nodule symbioses with nitrogen-fixing bacteria (rhizobia), whereas most flowering plants establish symbiotic associations with arbuscular mycorrhizal (AM) fungi. Once first steps of symbiosis are initiated, nodule formation and mycorrhization in legumes is negatively controlled by a shoot-derived inhibitor (SDI), a phenomenon termed autoregulation. According to current views, autoregulation of nodulation and mycorrhization in legumes is regulated in a similar way. CLE peptides induced in response to rhizobial nodulation signals (Nod factors) have been proposed to represent the ascending long-distance signals to the shoot. Although not proven yet, these CLE peptides are likely perceived by leucine-rich repeat (LRR) autoregulation receptor kinases in the shoot. Autoregulation of mycorrhization in non-legumes is reminiscent to the phenomenon of “systemic acquired resistance” in plant-pathogen interactions. PMID:21455020

  16. Long-Distance Quantum Communication with Neutral Atoms

    CERN Document Server

    Razavi, M; Razavi, Mohsen; Shapiro, Jeffrey H.

    2005-01-01

    The architecture proposed by Duan, Lukin, Cirac, and Zoller (DLCZ) for long-distance quantum communication with atomic ensembles is analyzed. Its fidelity and throughput in entanglement distribution, entanglement swapping, and quantum teleportation is derived within a framework that accounts for multiple excitations in the ensembles as well as loss and asymmetries in the channel. The DLCZ performance metrics that are obtained are compared to the corresponding results for the trapped-atom quantum communication architecture that has been proposed by a team from the Massachusetts Institute of Technology and Northwestern University (MIT/NU). Both systems are found to be capable of high-fidelity entanglement distribution. However, the DLCZ scheme only provides conditional teleportation and repeater operation, whereas the MIT/NU architecture affords full Bell-state measurements on its trapped atoms. Moreover, it is shown that achieving unity conditional fidelity in DLCZ teleportation and repeater operation requires...

  17. Long-distance transport of endogenous gibberellins in Arabidopsis.

    Science.gov (United States)

    Regnault, Thomas; Davière, Jean-Michel; Achard, Patrick

    2016-01-01

    Gibberellins (GAs) are phytohormones controlling major aspects of plant growth and development. Although previous studies suggested the existence of a transport of GAs in plants, the nature and properties associated with this transport were unknown. We recently showed through micrografting and biochemical approaches that the GA12 precursor is the chemical form of GA undergoing long-distance transport across plant organs in Arabidopsis. Endogenous GA12 moves through the plant vascular system from production sites to recipient tissues, in which GA12 can be converted to bioactive forms to support growth via the activation of GA-dependent processes. GAs are also essential to promote seed germination; hence GA biosynthesis mutants do not germinate without exogenous GA treatment. Our results suggest that endogenous GAs are not (or not sufficiently) transmitted to the offspring to successfully complete the germination under permissive conditions.

  18. LIVING LONG-DISTANCE RELATIONSHIPS THROUGH COMPUTER-MEDIATED COMMUNICATION

    Directory of Open Access Journals (Sweden)

    Almond Pilar N. Aguila

    2009-12-01

    Full Text Available Overseas Filipino Workers (OFWs and their loved ones in thePhilippines manage to have dynamic relationships despite physical distance with Computer-Mediated Communication (CMC or the use of new media (the Internet and cellular phone. Theoretically guided by Marshall McLuhan and Stuart Hall, this paper presents three case studies that depict how individuals mindfully use communication technology to enact their relationships. Such interactions also entail the exchange of new ideas on gender roles, family relations, and dominant-subordinate roles that lead to cultural change. Conclusively, technology has made it easier for OFWs and their loved ones to overcome their aversion to being in long-distance relationships and overseas employment.

  19. Next Generation Large Capacity Long Distance Fiber To The Home

    Directory of Open Access Journals (Sweden)

    N. M. A. Ayad and M. Elazazy

    2011-07-01

    Full Text Available Optical device technologies for photonic networks, are focusing on integrated optical device technologies for digital coherent optical transmission technologies. With the rapid spread of fiber to the home (FTTH, broadband video services and mobile Internet devices now require a highly functional optical network infrastructure with a large capacity 100-Gbit/s/channel system based on digital coherent technology is considered to be a promising candidate for next-generation large-capacity long-distance optical communication systems. The optical components required for such systems, such as Polarization Division Multiplexed Quadrate Phase Shift Keying (PDM-QPSK optical modulator, integrated receiver, and local light source, are under development. Opto-electrical integration technologies, which enable us to construct small, low-cost, and highly functional optical components, will play an important role in providing cost-effective transmission equipment for future 100-Gbit/s/ch and post-100-Gbit/s/ch optical communications

  20. Long-distance practical quantum key distribution by entanglement swapping

    CERN Document Server

    Scherer, Artur; Tittel, Wolfgang

    2010-01-01

    We develop a model for practical, entanglement-based long-distance quantum key distribution employing entanglement swapping as a key building block. Relying only on existing off-the-shelf technology, we show how to optimize resources so as to maximize secret key distribution rates. The tools comprise lossy transmission links, such as telecom optical fibers or free space, parametric down-conversion sources of entangled photon pairs, and threshold detectors that are inefficient and have dark counts. Our analysis provides the optimal trade-off between detector efficiency and dark counts, which are usually competing, as well as the optimal source brightness that maximizes the secret key rate for specified distances (i.e. loss) between sender and receiver.

  1. Exploring characteristics and motives of long distance commuter cyclists

    DEFF Research Database (Denmark)

    Hansen, Karsten Bruun; Nielsen, Thomas Alexander Sick

    2014-01-01

    , commuter cyclists (>5 km from home to work) have more mobility options, higher incomes, and a longer education than other commuter cyclists. The main motive for longer distance cycling is physical exercise, followed by reduced costs and time used for traveling. The long distance commuter cyclists surveyed...... are very positive about their commute - pointing to positive experiences, better mood, and stress relief as experiences related to their cycle trip to work. Policy support should devote attention to unlocking the potential that may be embedded in individuals combining their exercise and travel time......, budgets to promote active travel to work as well as the role of psychological benefits as a factor in promoting and sustaining cycling practices....

  2. Exploring characteristics and motives of long distance commuter cyclists

    DEFF Research Database (Denmark)

    Hansen, Karsten Bruun; Sick Nielsen, Thomas

    2014-01-01

    , commuter cyclists (45 km from home to work) have more mobility options, higher incomes, and a longer education than other commuter cyclists. The main motive for longer distance cycling is physical exercise, followed by reduced costs and time used for traveling. The long distance commuter cyclists surveyed...... are very positive about their commute - pointing to positive experiences, better mood, and stress relief as experiences related to their cycle trip to work. Policy support should devote attention to unlocking the potential that may be embedded in individuals combining their exercise and travel time......, budgets to promote active travel to work as well as the role of psychological benefits as a factor in promoting and sustaining cycling practices....

  3. Long-distance singularities in multi-leg scattering amplitudes

    CERN Document Server

    Gardi, Einan; Duhr, Claude

    2016-01-01

    We report on the recent completion of the three-loop calculation of the soft anomalous dimension in massless gauge-theory scattering amplitudes. This brings the state-of-the-art knowledge of long-distance singularities in multi-leg QCD amplitudes with any number of massless particles to three loops. The result displays some novel features: this is the first time non-dipole corrections appear, which directly correlate the colour and kinematic degrees of freedom of four coloured partons. We find that non-dipole corrections appear at three loops also for three coloured partons, but these are independent of the kinematics. The final result is remarkably simple when expressed in terms of single-valued harmonic polylogarithms, and it satisfies several non-trivial constraints. In particular, it is consistent with the high-energy limit behaviour and it satisfies the expected factorization properties in two-particle collinear limits.

  4. 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

    Crocodylus acutus (American Crocodile) is the most widely distributed New World crocodilian species with its range extending from Peru in the south to the southern tip of peninsular Florida in the north. Crocodylus acutus occupies primarily coastal brackish water habitat, however it also occurs in freshwater to hypersaline habitats (Thorbjarnarson 2010. In Crocodiles. Status Survey and Conservation Action Plan. [Third Edition], American Crocodile Crocodylus acutus, pp. 46–53 S.C. Manolis and C. Stevenson. Crocodile Specialist Group, Darwin). There is limited literature on long distance movements of juvenile crocodilians worldwide and no literature on juvenile crocodiles in Florida. However, adult C. acutus in Florida have been documented to make seasonal movements of 5–15 km from preferred foraging habitat to nesting beaches (Mazzotti 1983. The Ecology of Crocodylus acutus in Florida. PhD Dissertation. The Pennsylvania State University, University Park, Pennsylvania. 161pp), and one adult was documented making a 35 km trip from her nest site to preferred foraging habitat (Cherkiss et. al. 2006. Herpetol. Rev. 38:72–73). Rodda (1984. Herpetologica 40:444–451) reported on juvenile C. acutus movement in Gatun Lake, Panama, and found that juveniles stayed within 1 km of their nest site for the first month. Movements of juvenile Crocodylus porosus (Saltwater Crocodile) in a river system in Northern Australia showed a maximum movement of 38.9 km from a known nest site, with the majority of the crocodiles staying within 15.6 km downstream to 6.8 km upstream (Webb and Messel 1978. Aust. Wildlife Res. 5:263–283). Juvenile movement of Crocodylus niloticus (Nile Crocodile) in Lake Ngezi, Zimbabwe showed crocodiles restricted their movements from 1.0 km up to 4.5 km through the wet and dry seasons (Hutton 1989. Am. Zool. 29:1033–1049). Long distance movements of alligators were recorded for sizes ranging from 28 cm to 361 cm in a coastal refuge in Louisiana, where

  5. Scorpio and Long-Distance Trade in Mesoamerica

    Science.gov (United States)

    Fahmel Beyer, Bernd

    2016-11-01

    This paper establishes a relationship between Scorpio and the astronomical group of the Ciudadela at Teotihuacan, linking them to the city's merchant elite. Its argument is based on a brief discussion of the alacrán and the context in which it appears in Prehispanic documents and art. Human figures with a scorpion-tail are emphasized because of their association with the merchant class and Venus. The iconography used to represent this star takes on many shapes, some of which were related to war. The origin of this symbol can be found on the southern coast of Guatemala, from where cacao was distributed to Oaxaca and the highlands. During the Postclassic the Soconusco was one of the most cherished domains of the Aztec, whose pochteca not only carried out long-distance trade but also had the power to solve or promote diplomatic conflicts.

  6. FT and florigen long-distance flowering control in plants.

    Science.gov (United States)

    Putterill, Joanna; Varkonyi-Gasic, Erika

    2016-10-01

    The great hunt for florigen, the universal, long distance flowering regulator proposed by Chailakhan in the 1930s, resulted in the discovery a decade ago that FT-like proteins fulfilled the predictions for florigen. They are small (∼175 amino acids), globular, phosphatidylethanolamine-binding (PEBP) proteins, phloem-expressed, graft-transmissible and able to move to the shoot apex to act as potent stimulators of flowering in many plants. Genes that regulate Arabidopsis FT protein movement and some features of Arabidopsis FT protein that make it an effective florigen have recently been identified. Although floral promotion via graft transmission of FT has not been demonstrated in trees, FT-like genes have been successfully applied to reducing the long juvenile (pre-flowering) phase of many trees enabling fast track breeding.

  7. Long Distance Transference of Height Daum Across Seas

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This paper focuses on studying long distance transference of height datum across seas by combining ellipsoidal height derived from GPS with gravimetric geoid height.The Yellow Sea Height Datum is transferred to Yangshan Island which is 30 km away from Luchaogang in Shanghai.The stations heights derived in this way are compared with those determined from two independent sets of the tidal observations taken in two years,and the difference values are 1.0 cm and 6.0 cm,respectively.Moreover,the derived height differences between two sections on the island are also compared with the values derived from precise leveling with respect to the same section.The result shows that the inconsistencies are only 0.2 cm and 0.7 cm,respectively.

  8. Long-distance quantum key distribution in optical fiber

    CERN Document Server

    Hiskett, P A; Lita, A E; Miller, A J; Nam, S; Nordholt, J E; Peterson, C G; Rosenberg, D

    2006-01-01

    Use of low-noise detectors can both increase the secret bit rate of long-distance quantum key distribution (QKD) and dramatically extend the length of a fibre optic link over which secure key can be distributed. Previous work has demonstrated use of ultra-low-noise transition-edge sensors (TESs) in a QKD system with transmission over 50 km. In this work, we demonstrate the potential of the TESs by successfully generating error-corrected, privacy-amplified key over 148.7 km of dark optical fibre at a mean photon number mu = 0.1, or 184.6 km of dark optical fibre at a mean photon number of 0.5. We have also exchanged secret key over 67.5 km that is secure against powerful photon-number-splitting attacks.

  9. Estuarine crocodiles ride surface currents to facilitate long-distance travel.

    Science.gov (United States)

    Campbell, Hamish A; Watts, Matthew E; Sullivan, Scott; Read, Mark A; Choukroun, Severine; Irwin, Steve R; Franklin, Craig E

    2010-09-01

    1. The estuarine crocodile (Crocodylus porosus) is the world's largest living reptile. It predominately inhabits freshwater and estuarine habitats, but widespread geographic distribution throughout oceanic islands of the South-east Pacific suggests that individuals undertake sizeable ocean voyages. 2. Here we show that adult C. porosus adopt behavioural strategies to utilise surface water currents during long-distance travel, enabling them to move quickly and efficiently over considerable distances. 3. We used acoustic telemetry to monitor crocodile movement throughout 63 km of river, and found that when individuals engaged in a long-distance, constant direction journey (>10 km day(-1)), they would only travel when current flow direction was favourable. Depth and temperature measurements from implanted transmitters showed that they remained at the water surface during travel but would dive to the river substratum or climb out on the river bank if current flow direction became unfavourable. 4. Satellite positional fixes from tagged crocodiles engaged in ocean travel were overlaid with residual surface current (RSC) estimates. The data showed a strong correlation existed between the bearing of the RSC and that of the travelling crocodile (r(2) = 0.92, P < 0.0001). 5. The study demonstrates that C. porosus dramatically increase their travel potential by riding surface currents, providing an effective dispersal strategy for this species.

  10. Long-Distance Wh-Movement and Long-Distance Wh-Movement Avoidance in L2 English: Evidence from French and Bulgarian Speakers

    Science.gov (United States)

    Slavkov, Nikolay

    2015-01-01

    This article investigates spoken productions of complex questions with long-distance wh-movement in the L2 English of speakers whose first language is (Canadian) French or Bulgarian. Long-distance wh-movement is of interest as it can be argued that it poses difficulty in acquisition due to its syntactic complexity and related high processing load.…

  11. Long-Distance Wh-Movement and Long-Distance Wh-Movement Avoidance in L2 English: Evidence from French and Bulgarian Speakers

    Science.gov (United States)

    Slavkov, Nikolay

    2015-01-01

    This article investigates spoken productions of complex questions with long-distance wh-movement in the L2 English of speakers whose first language is (Canadian) French or Bulgarian. Long-distance wh-movement is of interest as it can be argued that it poses difficulty in acquisition due to its syntactic complexity and related high processing load.…

  12. Long-distance quantum communication. Decoherence-avoiding mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Kolb Bernardes, Nadja

    2012-12-17

    Entanglement is the essence of most quantum information processes. For instance, it is used as a resource for quantum teleportation or perfectly secure classical communication. Unfortunately, inevitable noise in the quantum channel will typically affect the distribution of entanglement. Owing to fundamental principles, common procedures used in classical communication, such as amplification, cannot be applied. Therefore, the fidelity and rate of transmission will be limited by the length of the channel. Quantum repeaters were proposed to avoid the exponential decay with the distance and to permit long-distance quantum communication. Long-distance quantum communication constitutes the framework for the results presented in this thesis. The main question addressed in this thesis is how the performance of quantum repeaters are affected by various sources of decoherence. Moreover, what can be done against decoherence to improve the performance of the repeater. We are especially interested in the so-called hybrid quantum repeater; however, many of the results presented here are sufficiently general and may be applied to other systems as well. First, we present a detailed entanglement generation rate analysis for the quantum repeater. In contrast to what is commonly found in the literature, our analysis is general and analytical. Moreover, various sources of errors are considered, such as imperfect local two-qubit operations and imperfect memories, making it possible to determine the requirements for memory decoherence times. More specifically, we apply our formulae in the context of a hybrid quantum repeater and we show that in a possible experimental scenario, our hybrid system can create near-maximally entangled pairs over a distance of 1280 km at rates of the order of 100 Hz. Furthermore, aiming to protect the system against different types of errors, we analyze the hybrid quantum repeater when supplemented by quantum error correction. We propose a scheme for

  13. Long-distance communication between laryngeal carcinoma cells.

    Directory of Open Access Journals (Sweden)

    Ieva Antanavičiūtė

    Full Text Available Tunneling nanotubes and epithelial bridges are recently discovered new forms of intercellular communication between remote cells allowing their electrical synchronization, transfer of second messengers and even membrane vesicles and organelles. In the present study, we demonstrate for the first time in primary cell cultures prepared from human laryngeal squamous cell carcinoma (LSCC samples that these cells communicate with each other over long distances (up to 1 mm through membranous tunneling tubes (TTs, which can be open-ended or contain functional gap junctions formed of connexin 43. We found two types of TTs, containing F-actin alone or F-actin and α-tubulin. In the LSCC cell culture, we identified 5 modes of TT formation and performed quantitative assessment of their electrical properties and permeability to fluorescent dyes of different molecular weight and charge. We show that TTs, containing F-actin and α-tubulin, transport mitochondria and accommodate small DAPI-positive vesicles suggesting possible transfer of genetic material through TTs. We confirmed this possibility by demonstrating that even TTs, containing gap junctions, were capable of transmitting double-stranded small interfering RNA. To support the idea that the phenomenon of TTs is not only typical of cell cultures, we have examined microsections of samples obtained from human LSCC tissues and identified intercellular structures similar to those found in the primary LSCC cell culture.

  14. Energy efficiency and steam coal transport over long distances

    Directory of Open Access Journals (Sweden)

    Stala-Szlugaj Katarzyna

    2016-01-01

    Full Text Available Coal is one of the most important energy sources in the world. Its main consumers are the energy sector (with a 37-46% share in the years 1990-2014; 1.12-2.34 billion toe and industry (24-27%; 0.78-1.38 billion toe. Diversified distribution of coal deposits in the world in relation to its consumers means that it has to be transported over often very long distances. The global coal trade is dominated by maritime transport (90-94% in the years 2004-2014, and the share of transport by land is relatively smaller. The aim of the article was to calculate the index describing what part of the energy contained in the coal transported on a particular route is consumed by the train carrying it. Due to the dominant position of the Russian Federation in imports of coal to Poland, it was assumed that coal will be imported by rail from Kuzbass (Russia's largest coal basin. As a result of the calculation, it was found that the rate of energy consumption for transport of imported coal will be somewhere in the range of 9.22-15.26%. In the case of deliveries of hard coal from Polish producers to the power plants the calculated rate changes within the range of 0.55-0.58%.

  15. Albatross Long-Distance Navigation: Comparing Adults And Juveniles

    Science.gov (United States)

    Åkesson, Susanne; Weimerskirch, Henri

    2005-09-01

    Albatrosses are known for their extreme navigation performance enabling them to locate isolated breeding islands after long-distance migrations across open seas. Little is known about the migration of young albatrosses and how they reach the adults' navigation and foraging skills during the period of immaturity lasting several years and spent permanently flying across the open ocean. We tracked by satellite telemetry the dispersal and migration of 13 juvenile wandering albatrosses from the Crozet Islands during their first year at sea. The young albatrosses covered an average distance of 184,000 km during the first year, restricting their dispersal movement to the unproductive and low wind subtropical Indian Ocean and Tasman Sea. The juveniles initiated the migration by an innate phase of rapid dispersal encoded as a fixed flight direction assisted by southerly winds towards north and northeast. Thereafter each individual restricted its movement to a particular zone of the ocean that will possibly be used until they start breeding 7 10 years later and return in contact with breeding adults. This dispersal in young birds corresponds well with movements observed for adult non-breeding wandering albatrosses. The results show clearly an inherited ability to navigate back to already visited areas in young wandering albatrosses. The juvenile dispersal behaviour and migration at sea suggest a genetically based migration program, encoding navigation to a destination area used throughout the life.

  16. Pollen transport in the Shiyang River drainage, arid China

    Institute of Scientific and Technical Information of China (English)

    ZHU Yan; XIE Yaowen; CHENG Bo; CHEN Fahu; ZHANG Jiawu

    2003-01-01

    In order to assess the contribution of the pollen transported by wind and fluvial flows to the pollen spectra in Shiyang River drainage, a typical small endorheic drainage in arid lands of northwest China, preliminary studies on modern pollen rain along two transects with 91 surface soil samples, 8 atmospheric samples, 30 modern fluvial flow samples and 50 riverbed mud samples, were carried out. Results show that dispersal agents (air, flowing water) have dissimilareffects on transport of pollen and the structure of pollen spectra. Fluvial flow has a stronger capacity than wind to transport large quantities of pollen overlong distances. Pollen transported by fluvial flow makes a large contribution to the pollen spectra of riverbed alluvial sediments. Paleoenvironmental reconstructions undertaken using pollen spectra from fluvial sediments in arid lands arestrongly influenced by pollen transport. Therefore, the sources, the transportation agents and the depositional condition of pollen should be systematically investigated before pollen assemblages are used to derive the environmental significance in such settings.

  17. Relaxed molecular clock provides evidence for long-distance dispersal of Nothofagus (southern beech.

    Directory of Open Access Journals (Sweden)

    Michael Knapp

    2005-01-01

    Full Text Available Nothofagus (southern beech, with an 80-million-year-old fossil record, has become iconic as a plant genus whose ancient Gondwanan relationships reach back into the Cretaceous era. Closely associated with Wegener's theory of "Kontinentaldrift", Nothofagus has been regarded as the "key genus in plant biogeography". This paradigm has the New Zealand species as passengers on a Moa's Ark that rafted away from other landmasses following the breakup of Gondwana. An alternative explanation for the current transoceanic distribution of species seems almost inconceivable given that Nothofagus seeds are generally thought to be poorly suited for dispersal across large distances or oceans. Here we test the Moa's Ark hypothesis using relaxed molecular clock methods in the analysis of a 7.2-kb fragment of the chloroplast genome. Our analyses provide the first unequivocal molecular clock evidence that, whilst some Nothofagus transoceanic distributions are consistent with vicariance, trans-Tasman Sea distributions can only be explained by long-distance dispersal. Thus, our analyses support the interpretation of an absence of Lophozonia and Fuscospora pollen types in the New Zealand Cretaceous fossil record as evidence for Tertiary dispersals of Nothofagus to New Zealand. Our findings contradict those from recent cladistic analyses of biogeographic data that have concluded transoceanic Nothofagus distributions can only be explained by vicariance events and subsequent extinction. They indicate that the biogeographic history of Nothofagus is more complex than envisaged under opposing polarised views expressed in the ongoing controversy over the relevance of dispersal and vicariance for explaining plant biodiversity. They provide motivation and justification for developing more complex hypotheses that seek to explain the origins of Southern Hemisphere biota.

  18. Bee Pollen

    Science.gov (United States)

    ... It can also include some nectar and bee saliva. Pollens come from many plants, so the contents ... rash. You may hear claims that bee pollen enzymes (chemical compounds that assist in chemical reactions) provide ...

  19. 干旱区石羊河流域河水孢粉组合特征%Pollen Assemblage Features of Modern Water Samples from the Shiyang River Drainage, Arid Region of China

    Institute of Scientific and Technical Information of China (English)

    朱艳; 陈发虎; 程波; 张家武; David B MADSEN

    2002-01-01

    Pollen analysis of 30 modern water samples from the Shiyang River, an internal river system located between the Tengger and Badain Jaran deserts, Northwest China was carried out to examine the river's capacity to carry pollen and spores, and to assess the contribution of the water-borne pollen to pollen assemblages in lake sediments at the end of the river system. Results indicate the pollen assemblages in water samples consist of both local and upland pollen. Percentages of upland pollen reach 30%-60%, and pollen assemblages in water samples do not indicate the nature of local vegetation at the sampling sites. Fluvial currents have the capacity to transport large quantities of pollen long distances, and the contribution of this fluvial transported pollen is relatively high. For example, percentages of Picea Dietr. pollen in water samples at sampling sites 130 km and 145 km away from Picea forests reach 16.5% and 7.7%, respectively. Fluvial pollen transport occurs primarily during flood periods, and pollen concentrations from the flood samples are 17.1-12.5 times those from normal fluvial flow. Reservoirs affect pollen transportation since pollen is deposited at reservoir inlets and pollen concentrations are much reduced at reservoir outlets. Human activity can thus change natural features of pollen transportation and deposition. The main factors influencing pollen concentrations and assemblages are sampling time, sampling location, and rainfall intensity.%石羊河流域初春和仲夏两季不同地点,洪水期、平水期30个河水样孢粉分析显示, 没有人类影响的情况下,河水样孢粉组合是由河流上游径流区的植物孢粉和采样点附近植被孢粉组成的,前者在孢粉组合中至少占30%~60%.河水搬运孢粉的能力非常强,可长距离、大量地搬运孢粉.孢粉组合中河水贡献孢粉的含量较高,如:云杉属(Picea Dietr.)花粉河水的贡献率在中下游可达16.5%和7.7%.采样时间、地点影响河

  20. Overview of the long distance iron ore slurry pipeline from Anglo Ferrous Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Adarlan M.; Passos, Aline C.; Santos, Daniel; Orban, Eduardo M.; Lisboa, Helder D.; Goncalves, Nilton; Guimaraes, Robson C. [Anglo Ferrous Brazil, Rio de Janeiro, RJ (Brazil)

    2009-07-01

    The objective of this paper is to present an overview of the long distance iron ore slurry pipeline from Anglo Ferrous Brazil. Anglo Ferrous Brazil is a company of Anglo American plc that is one of the world's largest mining and natural resource company. Minas-Rio is a world class iron ore project which has been developed in Brazil aiming to produce 26.6 million tons per year of concentrate. The mine, concentrator and pump station 1 will be located in Conceicao do Mato Dentro, Minas Gerais state, and the terminal station will be located at Acu Port in Sao Joao da Barra, Rio de Janeiro state. The long distance iron ore slurry pipeline will be one of major differentials of Minas-Rio Project and its useful life was initially estimated in 20 years. The slurry pipeline has a total length of 525 kilometers and will be constructed from predominately 26 inches external diameter API 5L X70 pipes. From kilometer 314 to kilometer 480, 24 inches pipe will be installed to prevent slack flow downstream pump station 2. The pump station 1 is designed to provide the hydraulic head necessary to transport the concentrate iron ore slurry with 8 positive displacement pumps to pump station 2. The pump station 2, located 240 kilometers downstream pump station 1, is designed to operate with 10 positive displacement pumps. The valve station will be located at kilometer 347 and will be used to break the static head between pump station 2 and the terminal station during a slurry pipeline shutdown. (author)

  1. How important is long-distance seed dispersal for the regional survival of plant species?

    NARCIS (Netherlands)

    Soons, M.B.; Ozinga, W.A.

    2005-01-01

    Long-distance seed dispersal is generally assumed to be important for the regional survival of plant species. In this study, we quantified the importance of long-distance seed dispersal for regional survival of plant species using wind dispersal as an example. We did this using a new approach, by fi

  2. How important is long-distance seed dispersal for the regional survival of plant species?

    NARCIS (Netherlands)

    Soons, M.B.; Ozinga, W.A.

    2005-01-01

    Long-distance seed dispersal is generally assumed to be important for the regional survival of plant species. In this study, we quantified the importance of long-distance seed dispersal for regional survival of plant species using wind dispersal as an example. We did this using a new approach, by

  3. Pollen-Mediated Gene Flow in Maize: Implications for Isolation Requirements and Coexistence in Mexico, the Center of Origin of Maize.

    Directory of Open Access Journals (Sweden)

    Baltazar M Baltazar

    Full Text Available Mexico, the center of origin of maize (Zea mays L., has taken actions to preserve the identity and diversity of maize landraces and wild relatives. Historically, spatial isolation has been used in seed production to maintain seed purity. Spatial isolation can also be a key component for a strategy to minimize pollen-mediated gene flow in Mexico between transgenic maize and sexually compatible plants of maize conventional hybrids, landraces, and wild relatives. The objective of this research was to generate field maize-to-maize outcrossing data to help guide coexistence discussions in Mexico. In this study, outcrossing rates were determined and modeled from eight locations in six northern states, which represent the most economically important areas for the cultivation of hybrid maize in Mexico. At each site, pollen source plots were planted with a yellow-kernel maize hybrid and surrounded by plots with a white-kernel conventional maize hybrid (pollen recipient of the same maturity. Outcrossing rates were then quantified by assessing the number of yellow kernels harvested from white-kernel hybrid plots. The highest outcrossing values were observed near the pollen source (12.9% at 1 m distance. The outcrossing levels declined sharply to 4.6, 2.7, 1.4, 1.0, 0.9, 0.5, and 0.5% as the distance from the pollen source increased to 2, 4, 8, 12, 16, 20, and 25 m, respectively. At distances beyond 20 m outcrossing values at all locations were below 1%. These trends are consistent with studies conducted in other world regions. The results suggest that coexistence measures that have been implemented in other geographies, such as spatial isolation, would be successful in Mexico to minimize transgenic maize pollen flow to conventional maize hybrids, landraces and wild relatives.

  4. Pollen-Mediated Gene Flow in Maize: Implications for Isolation Requirements and Coexistence in Mexico, the Center of Origin of Maize.

    Science.gov (United States)

    Baltazar, Baltazar M; Castro Espinoza, Luciano; Espinoza Banda, Armando; de la Fuente Martínez, Juan Manuel; Garzón Tiznado, José Antonio; González García, Juvencio; Gutiérrez, Marco Antonio; Guzmán Rodríguez, José Luis; Heredia Díaz, Oscar; Horak, Michael J; Madueño Martínez, Jesús Ignacio; Schapaugh, Adam W; Stojšin, Duška; Uribe Montes, Hugo Raúl; Zavala García, Francisco

    2015-01-01

    Mexico, the center of origin of maize (Zea mays L.), has taken actions to preserve the identity and diversity of maize landraces and wild relatives. Historically, spatial isolation has been used in seed production to maintain seed purity. Spatial isolation can also be a key component for a strategy to minimize pollen-mediated gene flow in Mexico between transgenic maize and sexually compatible plants of maize conventional hybrids, landraces, and wild relatives. The objective of this research was to generate field maize-to-maize outcrossing data to help guide coexistence discussions in Mexico. In this study, outcrossing rates were determined and modeled from eight locations in six northern states, which represent the most economically important areas for the cultivation of hybrid maize in Mexico. At each site, pollen source plots were planted with a yellow-kernel maize hybrid and surrounded by plots with a white-kernel conventional maize hybrid (pollen recipient) of the same maturity. Outcrossing rates were then quantified by assessing the number of yellow kernels harvested from white-kernel hybrid plots. The highest outcrossing values were observed near the pollen source (12.9% at 1 m distance). The outcrossing levels declined sharply to 4.6, 2.7, 1.4, 1.0, 0.9, 0.5, and 0.5% as the distance from the pollen source increased to 2, 4, 8, 12, 16, 20, and 25 m, respectively. At distances beyond 20 m outcrossing values at all locations were below 1%. These trends are consistent with studies conducted in other world regions. The results suggest that coexistence measures that have been implemented in other geographies, such as spatial isolation, would be successful in Mexico to minimize transgenic maize pollen flow to conventional maize hybrids, landraces and wild relatives.

  5. Pollen dispersal analysis using DNA markers

    OpenAIRE

    Wei Zhou; Hong Wang

    2014-01-01

    Modes of pollen dispersal are important for plant ecology, conservation, and evolutionary biology as pollen-mediated gene flow connects one generation of sexually-reproducing plants to the next. With the development of DNA molecular techniques, molecular markers (especially microsatellite markers) have replaced traditional physical markers for pollen flow analysis. Methods of paternity assignment with maximum likelihood and Bayesian inference have greatly improved the estimation of pollen flo...

  6. Hygroscopic weight gain of pollen grains from Juniperus species

    Science.gov (United States)

    Bunderson, Landon D.; Levetin, Estelle

    2015-05-01

    Juniperus pollen is highly allergenic and is produced in large quantities across Texas, Oklahoma, and New Mexico. The pollen negatively affects human populations adjacent to the trees, and since it can be transported hundreds of kilometers by the wind, it also affects people who are far from the source. Predicting and tracking long-distance transport of pollen is difficult and complex. One parameter that has been understudied is the hygroscopic weight gain of pollen. It is believed that juniper pollen gains weight as humidity increases which could affect settling rate of pollen and thus affect pollen transport. This study was undertaken to examine how changes in relative humidity affect pollen weight, diameter, and settling rate. Juniperus ashei, Juniperus monosperma, and Juniperus pinchotii pollen were applied to greased microscope slides and placed in incubation chambers under a range of temperature and humidity levels. Pollen on slides were weighed using an analytical balance at 2- and 6-h intervals. The size of the pollen was also measured in order to calculate settling rate using Stokes' Law. All pollen types gained weight as humidity increased. The greatest settling rate increase was exhibited by J. pinchotii which increased by 24 %.

  7. Long-distance entanglement and quantum communication in coupled cavity arrays

    CERN Document Server

    Giampaolo, S M

    2009-01-01

    We introduce quantum spin models that allow for long-distance end-to-end entanglement and long-distance, high-fidelity teleportation, even at moderately high temperatures. We show how these models, that realize an optimal compromise between scalability and resilience to decoherence, can be implemented in simply engineered arrays of coupled optical cavities. We demonstrate how the latter can be used to realize a quasi-deterministic scheme of long-distance quantum communication with high success rate, without direct projection on Bell states and Bell measurements.

  8. Interpersonal conflict and health perceptions in long-distance caregiving relationships.

    Science.gov (United States)

    Bevan, Jennifer L; Vreeburg, Sean K; Verdugo, Sherri; Sparks, Lisa

    2012-08-01

    With job markets expanding globally and life expectancy continually increasing, more demands are being placed on distant relatives to provide care for their aging family members, creating a health care situation known as long-distance caregiving. An online survey explored the relations between negative health perceptions by long-distance caregivers and conflict frequency and conflict strategy usage. The authors observed positive significant relations between distant caregiver negative health perceptions and conflict frequency and usage of the distributive and avoidance conflict strategies. However, they observed no significant associations between distant caregiver negative health perceptions and usage of the two integrative strategies. Implications for long-distance caregiving communication are discussed.

  9. Pollen-mediated gene flow from glyphosate-resistant common waterhemp (Amaranthus rudis Sauer): consequences for the dispersal of resistance genes

    Science.gov (United States)

    Sarangi, Debalin; Tyre, Andrew J.; Patterson, Eric L.; Gaines, Todd A.; Irmak, Suat; Knezevic, Stevan Z.; Lindquist, John L.; Jhala, Amit J.

    2017-01-01

    Gene flow is an important component in evolutionary biology; however, the role of gene flow in dispersal of herbicide-resistant alleles among weed populations is poorly understood. Field experiments were conducted at the University of Nebraska-Lincoln to quantify pollen-mediated gene flow (PMGF) from glyphosate-resistant (GR) to -susceptible (GS) common waterhemp using a concentric donor-receptor design. More than 130,000 common waterhemp plants were screened and 26,199 plants were confirmed resistant to glyphosate. Frequency of gene flow from all distances, directions, and years was estimated with a double exponential decay model using Generalized Nonlinear Model (package gnm) in R. PMGF declined by 50% at pollen source, whereas 90% reduction was found at 88 m (maximum) depending on the direction of the pollen-receptor blocks. Amplification of the target site gene, 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), was identified as the mechanism of glyphosate resistance in parent biotype. The EPSPS gene amplification was heritable in common waterhemp and can be transferred via PMGF, and also correlated with glyphosate resistance in pseudo-F2 progeny. This is the first report of PMGF in GR common waterhemp and the results are critical in explaining the rapid dispersal of GR common waterhemp in Midwestern United States. PMID:28327669

  10. High rates of gene flow by pollen and seed in oak populations across Europe

    NARCIS (Netherlands)

    Gerber, S.; Chadoeuf, J.; Gugerli, F.; Lascoux, M.; Buiteveld, J.; Cottrell, J.; Dounavi, A.; Fineschi, S.; Forrest, L.; Fogelqvist, J.; Goicoechea, P.G.; Jensen, J.S.; Salvini, D.; Vendramin, G.G.; Kremer, A.

    2014-01-01

    Gene flow is a key factor in the evolution of species, influencing effective population size, hybridisation and local adaptation. We analysed local gene flow in eight stands of white oak (mostly Quercus petraea and Q. robur, but also Q. pubescens and Q. faginea) distributed across Europe. Adult tree

  11. Daily Ambrosia Pollen Concentration in the Air of Ankara,Turkey (1990-1999)

    Institute of Scientific and Technical Information of China (English)

    Ayse KAPLAN; Nazmiye SAKIYAN; N Münevver PINAR

    2003-01-01

    The airborne ragweed pollen spectrum was investigated in the air of Ankara, Turkey for aperiod of ten years (1990-1999) using a Burkard seven-day volumetric recording trap. In our study period,long distance transported Ambrosia pollen has been registered. Daily pollen levels varied from low to highin Burge's system. In last three years, the pollen concentration of Ambrosia showed a clear increasingtendency. Our results prove that ragweed pollen may be an important threat for ragweed sensitive patientsin Ankara city in near future.

  12. The occurrence of Ambrosia pollen in the atmosphere of Northwest Turkey: investigation of possible source regions

    Science.gov (United States)

    Celenk, Sevcan; Malyer, Hulusi

    2017-02-01

    Ambrosia pollen was first reported as an important allergen in North America at the end of the nineteenth century, and many European countries have recently reported its increasing significance for pollen allergy. The aims of this study were to determine whether the highly allergenic Ambrosia pollen recorded during the studied period could be the result of long-distance transport (LDT) and to identify the potential sources of Ambrosia pollen grains. The study investigates Ambrosia pollen episodes during the peak term of six yearly periods between 2010 and 2015 by examining source regions in Ambrosia pollen in Bursa, Turkey. A volumetric trap was used for collecting the pollen samples, and the back-trajectory model was used to identify a potential source of atmospheric Ambrosia pollen. The days when pollen levels exceeded 30 P m-3 were computed, and clusters were shown on the figures. The study indicates that the Ambrosia pollen grains recorded during the episode in Bursa were not produced by local sources but transported long distances from potential source regions around the Azov Sea in Russia and Ukraine, Black Sea region of Turkey, Romania, and Bulgaria. Note that atmospheric concentrations of Ambrosia pollen exceeded the clinical threshold during 28 days during the investigation period. Taking into consideration the high allergenicity of Ambrosia pollen, the present findings suggest that the number of ragweed-sensitized individuals might increase in the near future in the region.

  13. Surface modification of poly (vinyl chloride) by long-distance and direct argon RF plasma

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This paper reports the effects of long- distance and direct argon radio frequency (RF) plasma surface treatment on polyvinyl chloride (PVC) films in terms of changes in surface wettability and surface chemistry. The surface properties are characterized by the water contact angle measurement, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The mechanism is further analyzed and the role of all kinds of active species, e.g. electrons, ions and free radicals involved in plasma surface modification is further evaluated. Results show that the long-distance and direct RF plasma treatments modify the PVC surface in morphology and composition, and both modifications cause surface oxidation of PVC films, in the forming of functional groups enhancing polymer wettability. The effect of the long-distance argon RF plasma is more notable. This suggests that long-distance argon RF plasma could restrain the ion and electron eroding effect and enhance free radical reaction.

  14. Telephone and Cable Lines, Long Distance, Published in Not Provided, US Army.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Telephone and Cable Lines, Long Distance dataset as of Not Provided. Data by this publisher are often provided in Not Applicable coordinate system; in a Not...

  15. Pollen flow and effects of population structure on selfing rates and female and male reproductive success in fragmented Magnolia stellata populations

    OpenAIRE

    Setsuko, Suzuki; Nagamitsu, Teruyoshi; Tomaru, Nobuhiro

    2013-01-01

    Background Fragmentation of plant populations may affect mating patterns and female and male reproductive success. To improve understanding of fragmentation effects on plant reproduction, we investigated the pollen flow patterns in six adjacent local populations of Magnolia stellata, an insect-pollinated, threatened tree species in Japan, and assessed effects of maternal plant (genet) size, local genet density, population size and neighboring population size on female reproductive success (se...

  16. How important is long-distance seed dispersal for the regional survival of plant species?

    OpenAIRE

    Soons, M.B.; Ozinga, W.A.

    2005-01-01

    Long-distance seed dispersal is generally assumed to be important for the regional survival of plant species. In this study, we quantified the importance of long-distance seed dispersal for regional survival of plant species using wind dispersal as an example. We did this using a new approach, by first relating plant species' dispersal traits to seed dispersal kernels and then relating the kernels to regional survival of the species. We used a recently developed and tested mechanistic seed di...

  17. Renal function, aldosterone, and vasopressin excretion following repeated long-distance running.

    Science.gov (United States)

    Wade, C E; Dressendorfer, R H; O'Brien, J C; Claybaugh, J R

    1981-04-01

    Renal and endocrine responses were studied in 10 male runners during a 20-day 500-km race. Overnight urine and prerun blood samples were taken prior to running on days 1, 2, 5, 8, 14, 17, and 20. Day 13 followed 70 h of rest. Urine flow rate, osmotic clearance, tubular free water reabsorption, urinary vasopressin excretion rate, and body weight were not significantly changed. Creatinine clearance was constant except for an elevation on day 5. Plasma osmolality was elevated on days 2, 14, and 17. Plasma sodium was increased (P less than 0.05) on days 2 and 13 but reduced on day 20. The percentage of filtered sodium excreted was significantly reduced on all nights following running and elevated on recovery day 13. Urinary aldosterone excretion rate was significantly elevated 162, 117, and 97% on days 5, 8, and 20 and returned to control levels on day 13 after 70 h of rest. These data suggest that in response to repeated long-distance running normal fluid balance is regained within 12 h. However, it is necessary to conserve sodium for at least 24 h after exercise as evidenced by the decrease in the percent filtered sodium excreted and continued elevation of aldosterone excretion.

  18. Tree shoot bending generates hydraulic pressure pulses: a new long-distance signal?

    Science.gov (United States)

    Lopez, Rosana; Badel, Eric; Peraudeau, Sebastien; Leblanc-Fournier, Nathalie; Beaujard, François; Julien, Jean-Louis; Cochard, Hervé; Moulia, Bruno

    2014-05-01

    When tree stems are mechanically stimulated, a rapid long-distance signal is induced that slows down primary growth. An investigation was carried out to determine whether the signal might be borne by a mechanically induced pressure pulse in the xylem. Coupling xylem flow meters and pressure sensors with a mechanical testing device, the hydraulic effects of mechanical deformation of tree stem and branches were measured. Organs of several tree species were studied, including gymnosperms and angiosperms with different wood densities and anatomies. Bending had a negligible effect on xylem conductivity, even when deformations were sustained or were larger than would be encountered in nature. It was found that bending caused transient variation in the hydraulic pressure within the xylem of branch segments. This local transient increase in pressure in the xylem was rapidly propagated along the vascular system in planta to the upper and lower regions of the stem. It was shown that this hydraulic pulse originates from the apoplast. Water that was mobilized in the hydraulic pulses came from the saturated porous material of the conduits and their walls, suggesting that the poroelastic behaviour of xylem might be a key factor. Although likely to be a generic mechanical response, quantitative differences in the hydraulic pulse were found in different species, possibly related to differences in xylem anatomy. Importantly the hydraulic pulse was proportional to the strained volume, similar to known thigmomorphogenetic responses. It is hypothesized that the hydraulic pulse may be the signal that rapidly transmits mechanobiological information to leaves, roots, and apices.

  19. Pollen and seed mediated gene flow in commercial alfalfa seed production fields

    Science.gov (United States)

    The potential for gene flow has been widely recognized since alfalfa is pollinated by bees. The Western US is a major exporter of alfalfa seed and hay and the organic dairy industry is one of the fastest growing agricultural sectors. Because of this, many alfalfa producers are impacted by market sen...

  20. Low crop plant population densities promote pollen-mediated gene flow in spring wheat (Triticum aestivum L.).

    Science.gov (United States)

    Willenborg, Christian J; Brûlé-Babel, Anita L; Van Acker, Rene C

    2009-12-01

    Transgenic wheat is currently being field tested with the intent of eventual commercialization. The development of wheat genotypes with novel traits has raised concerns regarding the presence of volunteer wheat populations and the role they may play in facilitating transgene movement. Here, we report the results of a field experiment that investigated the potential of spring wheat plant population density and crop height to minimize gene flow from a herbicide-resistant (HR) volunteer population to a non-HR crop. Pollen-mediated gene flow (PMGF) between the HR volunteer wheat population and four conventional spring wheat genotypes varying in height was assessed over a range of plant population densities. Natural hybridization events between the two cultivars were detected by phenotypically scoring plants in F(1) populations followed by verification with Mendelian segregation ratios in the F(1:2) families. PMGF was strongly associated with crop yield components, but showed no association with flowering synchrony. Maximum observed PMGF was always less than 0.6%, regardless of crop height and density. The frequency of PMGF in spring wheat decreased exponentially with increasing plant population density, but showed no dependence on either crop genotype or height. However, increasing plant densities beyond the recommended planting rate of 300 cropped wheat plants m(-2) provided no obvious benefit to reducing PMGF. Nevertheless, our results demonstrate a critical plant density of 175-200 cropped wheat plants m(-2) below which PMGF frequencies rise exponentially with decreasing plant density. These results will be useful in the development of mechanistic models and best management practices that collectively facilitate the coexistence of transgenic and nontransgenic wheat crops.

  1. Non-linear relationship between hyperpolarisation and relaxation enables long distance propagation of vasodilatation.

    Science.gov (United States)

    Wölfle, Stephanie E; Chaston, Daniel J; Goto, Kenichi; Sandow, Shaun L; Edwards, Frank R; Hill, Caryl E

    2011-05-15

    Blood flow is adjusted to tissue demand through rapidly ascending vasodilatations resulting from conduction of hyperpolarisation through vascular gap junctions. We investigated how these dilatations can spread without attenuation if mediated by an electrical signal. Cremaster muscle arterioles were studied in vivo by simultaneously measuring membrane potential and vessel diameter. Focal application of acetylcholine elicited hyperpolarisations which decayed passively with distance from the local site,while dilatation spread upstream without attenuation. Analysis of simultaneous recordings at the local site revealed that hyperpolarisation and dilatation were only linearly related over a restricted voltage range to a threshold potential, beyond which dilatation was maximal. Experimental data could be simulated in a computational model with electrotonic decay of hyperpolarisation but imposition of this threshold. The model was tested by reducing the amplitude of the local hyperpolarisation which led to entry into the linear range closer to the local site and decay of dilatation. Serial section electron microscopy and light dye treatment confirmed that the spread of dilatation occurred through the endothelium and that the two cell layers were tightly coupled. Generality of the mechanism was demonstrated by applying the model to the attenuated propagation of dilatation found in larger arteries.We conclude that long distance spread of locally initiated dilatations is not due to a regenerative electrical phenomenon, but rather a restricted linear relationship between voltage and vessel tone, which minimises the impact of electrotonic decay of voltage. Disease-related alterations in endothelial coupling or ion channel expression could therefore decrease the ability to adjust blood flow to meet metabolic demand.

  2. Seed dispersal at alpine treeline: long distance dispersal maintains alpine treelines

    Science.gov (United States)

    Johnson, J. S.; Gaddis, K. D.; Cairns, D. M.; Krutovsky, K.

    2016-12-01

    Alpine treelines are expected to advance to higher elevations in conjunction with global warming. Nevertheless, the importance of reproductive method and seed dispersal distances at the alpine treeline ecotone remains unresolved. We address two research questions at mountain hemlock treelines on the Kenai Peninsula, Alaska: (1) What is the primary mode of reproduction, and (2) are recruits derived from local treeline populations or are they arriving from more distant seed sources? We addressed our research questions by exhaustively sampling mountain hemlock individuals along a single mountain slope and then genotyped DNA single nucleotide polymorphisms using a genotyping by sequencing approach (ddRAD Seq). First we assessed mode of reproduction by determining the proportion of sampled individuals with identical multilocus genotypes that are the product of clonal reproduction. Second, we used a categorical allocation based parentage analysis to identify parent-offspring pairs, so that the proportion of treeline reproduction events could be quantified spatially and dispersal distance measured. We identified sexual reproduction as the primary mode of reproduction at our study site. Seedling establishment was characterized by extensive cryptic seed dispersal and gene flow into the ecotone. The average dispersal distance was 73 meters with long distance dispersal identified as dispersal occurring at distances greater than 450 meters. We show that production of seeds within the alpine treeline ecotone is not a necessary requirement for treelines to advance to higher elevations in response to climate change. The extensive cryptic seed dispersal and gene flow into the alpine treeline ecotone is likely sufficient to propel the ecotone higher under more favorable climate.

  3. A study on sexual risk behaviors of long-distance truck drivers in central India

    Directory of Open Access Journals (Sweden)

    Aditya Thakur

    2015-07-01

    Full Text Available Background: The sexual behavior of trucking populations has been associated with the transmission of sexually transmitted infections (STI and HIV in India and elsewhere in the world. The objective of the study was to describe the Health seeking and sexual risks behaviors among the long distance truck drivers and to estimate the prevalence of STI symptoms in the long distance truck driver. Methods: Cross sectional study conducted on the Long Distance truck drivers plying on national highway passing through Bhopal state Highway, who halted at road side group of and ldquo;Dhabas and rdquo; (road side hotels at 3 exits ways of Bhopal City M.P (India. A total of 309 truck drivers approached over a period of 90 days. Out of these 251 consented for the study. Result: The study revealed that 49 % of the long distance truck driver had CSW exposure in last 6 months. The prevalence of STI symptoms was found to be 21.51 % among the long distance truck drivers. The Truck Driver who had exposure with CSW more than five times in the last 6 months were found to be more careless regarding using condoms while having intercourse with the CSW's. Conclusion: Effort like availability of condoms in the high risk group settings is required. Dhabas should be made to function as a sentinel centre for promoting awareness for HIV/AIDS and STIs. [Int J Res Med Sci 2015; 3(7.000: 1769-1774

  4. Land bridge and long-distance dispersal--Old views, new evidence

    Institute of Scientific and Technical Information of China (English)

    ZHOU Zhekun; YANG Xuefei; YANG Qingsong

    2006-01-01

    The study of land bridge based on con- tinental drift1) and long-distance dispersal are gaining increasing attention in biogeography. We review several major dispersal theories including the Mal- pigiacea route, patterns of chameleon dispersal and the floating island model. The Malpigiaceae route indicates that the Malpigiaceae family originated in northern South America and that members of several clades migrated into North America and subsequently moved via north Atlantic land connections into the Old World starting in the Eocene. This route may also explain many other pantropic disjunction patterns, including some Chinese plants disjunctions, involving South America. Not all biogeographical distribution patterns can be explained by vicariance theory, so more research, including chameleon distribution, has recently focused on long-distance dispersal. The lat- est analyses suggest that chameleons have dis- persed over long-distances from Madagascar on several occasions. The floating island model would explain flora and fauna similarities between South America and Africa. Studying long-distance dispersal mechanisms is important for understanding distribu- tion patterns and even the spread of pandemics. More research on the specific implications of long- distance dispersal for biogeography is necessary.

  5. Phloem RNA-binding proteins as potential components of the long-distance RNA transport system.

    Directory of Open Access Journals (Sweden)

    VICENTE ePALLAS

    2013-05-01

    Full Text Available RNA-binding proteins (RBPs govern a myriad of different essential processes in eukaryotic cells. Recent evidence reveals that apart from playing critical roles in RNA metabolism and RNA transport, RBPs perform a key function in plant adaption to various environmental conditions. Long distance RNA transport occurs in land plants through the phloem, a conducting tissue that integrates the wide range of signalling pathways required to regulate plant development and response to stress processes. The macromolecules in the phloem pathway vary greatly and include defence proteins, transcription factors, chaperones acting in long distance trafficking, and RNAs (mRNAs, siRNAs and miRNAs. How these RNA molecules translocate through the phloem is not well understood, but recent evidence indicates the presence of translocatable RNA-binding proteins in the phloem, which act as potential components of long distance RNA transport system. This review updates our knowledge on the characteristics and functions of RBPs present in the phloem.

  6. Mating patterns, pollen dispersal, and the ecological maternal neighbourhood in a Prunus mahaleb L. population.

    Science.gov (United States)

    García, C; Arroyo, J M; Godoy, J A; Jordano, P

    2005-05-01

    Gender polymorphism, plant-animal interactions, and environmental heterogeneity are the three important sources of variation in mating system and pollen dispersal patterns. We used progeny arrays and paternity analysis to assess the effects of gender type and density level on variation in mating patterns within a highly isolated population of Prunus mahaleb, a gynodioecious species. All the adult trees in the population were sampled and located. The direct estimate of long-distance insect-mediated pollination events was low ( 250 m) were significantly more frequent among female mother trees. Variation in local tree density also affected pollen pool diversity and intermate distance, with a higher effective number of fathers (k(e)) and longer intermate distances for female trees in low-density patches. A canonical correlation analysis showed significant correlations between mating variables and the maternal ecological neighbourhood. Only the first canonical variable was significant and explained 78% of variation. Outcrossing rates tended to decrease, and the relatedness among the fathers tended to increase, when mother trees grew in dense patches with high cover of other woody species and taller vegetation away from the pine forest edge. We highlight the relevance of considering maternal ecological neighbourhood effects on mating system and gene flow studies as maternal trees act simultaneously as receptors of pollen and as sources of the seeds to be dispersed.

  7. Dissipation Intermittency Increases Long-Distance Dispersal of Heavy Particles in the Canopy Sublayer

    Science.gov (United States)

    Duman, Tomer; Trakhtenbrot, Ana; Poggi, Davide; Cassiani, Massimo; Katul, Gabriel G.

    2016-04-01

    The dispersion of heavy particles such as seeds within canopies is evaluated using Lagrangian stochastic trajectory models, laboratory, and field experiments. Inclusion of turbulent kinetic energy dissipation rate intermittency is shown to increase long-distance dispersal (LDD) by contributing to the intermittent ejection of particles to regions of high mean velocity outside the canopy volume. Model evaluation against controlled flume experiments, featuring a dense rod canopy, detailed flow measurements, and imaged trajectories of spherical particles, demonstrates that superimposing a terminal velocity on the fluid velocity is insufficient to determine the particle dispersal kernel. Modifying the trajectory model by adding dissipation intermittency is found to be significant for dispersal predictions along with the addition of inertial and crossing trajectories' effects. Comparison with manual seed-release experiments in a forest using wind-dispersed seeds shows that the model captures most of the measured kernels when accepted uncertainties in plant area index and friction velocity are considered. Unlike the flume experiments, the model modifications for several wind-dispersed seeds have minor effects on short-distance dispersal. A large increase was predicted in LDD when including dissipation intermittency for the forest experiment. The main results suggest that fitting or calibrating models to the `main body' of measured kernels may not offer extrapolating foresight to LDD predictions. As inertial effects were found mostly negligible in the field conditions here, the extended trajectory model requires specifying only the seed's terminal velocity and a constant variance of the normalized dissipation rate. Therefore, the proposed modifications can be readily applied to classical trajectory models so as to improve LDD predictions.

  8. Parallel speciation or long-distance dispersal? Lessons from seaweeds (Fucus) in the Baltic Sea.

    Science.gov (United States)

    Pereyra, R T; Huenchuñir, C; Johansson, D; Forslund, H; Kautsky, L; Jonsson, P R; Johannesson, K

    2013-08-01

    Parallel evolution has been invoked as a forceful mechanism of ecotype and species formation in many animal taxa. However, parallelism may be difficult to separate from recently monophyletically diverged species that are likely to show complex genetic relationships as a result of considerable shared ancestral variation and secondary hybridization in local areas. Thus, species' degrees of reproductive isolation, barriers to dispersal and, in particular, limited capacities for long-distance dispersal will affect demographical structures underlying mechanisms of divergent evolution. Here, we used nine microsatellite DNA markers to study intra- and interspecific genetic diversity of two recently diverged species of brown macroalgae, Fucus radicans (L. Bergström & L. Kautsky) and F. vesiculosus (Linnaeus), in the Baltic Sea. We further performed biophysical modelling to identify likely connectivity patterns influencing the species' genetic structures. For each species, we found intraspecific contrasting patterns of clonality incidence and population structure. In addition, strong genetic differentiation between the two species within each locality supported the existence of two distinct evolutionary lineages (FST  = 0.15-0.41). However, overall genetic clustering analyses across both species' populations revealed that all populations from one region (Estonia) were more genetically similar to each other than to their own taxon from the other two regions (Sweden and Finland). Our data support a hypothesis of parallel speciation. Alternatively, Estonia may be the ancestral source of both species, but is presently isolated by oceanographic barriers to dispersal. Thus, a limited gene flow in combination with genetic drift could have shaped the seemingly parallel structure.

  9. Colonization of the Scottish islands via long-distance Neolithic transport of red deer (Cervus elaphus).

    Science.gov (United States)

    Stanton, David W G; Mulville, Jacqueline A; Bruford, Michael W

    2016-04-13

    Red deer (Cervus elaphus) have played a key role in human societies throughout history, with important cultural significance and as a source of food and materials. This relationship can be traced back to the earliest human cultures and continues to the present day. Humans are thought to be responsible for the movement of a considerable number of deer throughout history, although the majority of these movements are poorly described or understood. Studying such translocations allows us to better understand ancient human-wildlife interactions, and in the case of island colonizations, informs us about ancient human maritime practices. This study uses DNA sequences to characterise red deer genetic diversity across the Scottish islands (Inner and Outer Hebrides and Orkney) and mainland using ancient deer samples, and attempts to infer historical colonization events. We show that deer from the Outer Hebrides and Orkney are unlikely to have originated from mainland Scotland, implying that humans introduced red deer from a greater distance. Our results are also inconsistent with an origin from Ireland or Norway, suggesting long-distance maritime travel by Neolithic people to the outer Scottish Isles from an unknown source. Common haplotypes and low genetic differentiation between the Outer Hebrides and Orkney imply common ancestry and/or gene flow across these islands. Close genetic proximity between the Inner Hebrides and Ireland, however, corroborates previous studies identifying mainland Britain as a source for red deer introductions into Ireland. This study provides important information on the processes that led to the current distribution of the largest surviving indigenous land mammal in the British Isles. © 2016 The Authors.

  10. Allergies, asthma, and pollen

    Science.gov (United States)

    Reactive airway - pollen; Bronchial asthma - pollen; Triggers - pollen; Allergic rhinitis - pollen ... Things that make allergies or asthma worse are called triggers. It is important to know your triggers because avoiding them is your first step toward feeling better. ...

  11. The Role that φ-Features Play in Long Distance Binding

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    .INTRODUCTIONThis article attempts to investigate long distance binding in Chinese under a feature- orientated ap-proach based on the studies done by Battistella ( 1 989) ,Tang ( 1 986) ,Cole and Sung ( 1 990 ) and oth-ers.The data presented in this article demonstrated,contrary to the prevailing assumption that- fea-tures of reflexives in various language are base generated,long distance reflexives before movement atL F have barren or impoverishedφ- features.On this basis,itis demonstrated thata reflexive ...

  12. Reverse the force direction at long distance by quantum corrections with a mass

    CERN Document Server

    Chen, X S

    2005-01-01

    We demonstrate that quantum corrections can possibly reverse the sign of the one-particle-exchange potential (OPEP) at long distance if (and under general assumptions, only if) the exchanged particle has a mass $m$, either intrinsic or effective. Such phenomenon requires a running coupling constant $\\alpha(q^2)$ satisfying $\\alpha (-m^2)<0$ in the off-shell renormalization scheme. Reversal of the OPEP sign at long distance (and hence attraction transits to repulsion, or vice versa) may have important implications for gravity and cosmic acceleration, particle and nuclear physics, and also condensed matter properties such as superconductivity.

  13. Executive overview: welfare aspects of the long distance transportation of animals

    Directory of Open Access Journals (Sweden)

    David B. Adams

    2008-03-01

    Full Text Available A compendium of papers brings together a range of perspectives on the long distance transportation of animals. The purpose is to assist in the strengthening of global public policies for the protection of animal health and welfare. The audience targeted is the wide range of people involved in shaping sound public policy. Papers cover the history of long distance transportation of animals, the viewpoints of the foremost civil society organisations involved in the long distance transport of animals, how various governments approach public policy on the subject, the implementation of quality management for the transportation of different species of animals in different situations, future directions for quality management, design and engineering of infrastructures, transport safety and animal welfare and the education and training necessary for the successful management of animal welfare during long distance transportation. A seamless connection between animal health and animal welfare is an absolute necessity given the critical importance of animal movements in the spread of infection and the devastation to animal and human welfare produced by infectious disease. A compendium of papers brings together a range of perspectives on the long distance transportation of animals. The purpose is to assist in the strengthening of global public policies for the protection of animal health and welfare. The audience targeted is the wide range of people involved in shaping sound public policy. Papers cover the history of long distance transportation of animals, the viewpoints of the foremost civil society organisations involved in the long distance transport of animals, how various governments approach public policy on the subject, the implementation of quality management for the transportation of different species of animals in different situations, future directions for quality management, design and engineering of infrastructures, transport safety and animal

  14. Executive overview: welfare aspects of the long distance transportation of animals.

    Science.gov (United States)

    Adams, David B; Thornber, Peter M; Murray, Gardner

    2008-01-01

    A compendium of papers brings together a range of perspectives on the long distance transportation of animals. The purpose is to assist in the strengthening of global public policies for the protection of animal health and welfare. The audience targeted is the wide range of people involved in shaping sound public policy. Papers cover the history of long distance transportation of animals, the viewpoints of the foremost civil society organisations involved in the long distance transport of animals, how various governments approach public policy on the subject, the implementation of quality management for the transportation of different species of animals in different situations, future directions for quality management, design and engineering of infrastructures, transport safety and animal welfare and the education and training necessary for the successful management of animal welfare during long distance transportation. A seamless connection between animal health and animal welfare is an absolute necessity given the critical importance of animal movements in the spread of infection and the devastation to animal and human welfare produced by infectious disease. A compendium of papers brings together a range of perspectives on the long distance transportation of animals. The purpose is to assist in the strengthening of global public policies for the protection of animal health and welfare. The audience targeted is the wide range of people involved in shaping sound public policy. Papers cover the history of long distance transportation of animals, the viewpoints of the foremost civil society organisations involved in the long distance transport of animals, how various governments approach public policy on the subject, the implementation of quality management for the transportation of different species of animals in different situations, future directions for quality management, design and engineering of infrastructures, transport safety and animal welfare and the

  15. COMBINED GPS/GLONASS PRECISE POSITIONING FOR LONG-DISTANCE BASELINES

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Combined GPS/GLONASS can increase the accuracy and reliability ofpositioning especially in some applications with many impediments.Due to the atmosphere delay,the commonly used methods for processing short distance baselines can not be implemented in long distance baselines.In this paper,a new data processing strategy for long distance baselines is proposed,which uses the properties of some combination observables of combined GPS/GLONASS and distance baselines may come to the order of 10-8 and combined GPS/GLONASS improves the accuracy over that of GPS-only positioning,which brings benefit to crust deformation monitoring and research on geodynamics.

  16. Viability and seasonal distribution patterns of Scots pine pollen in Finland.

    Science.gov (United States)

    Pulkkinen, P.; Rantio-Lehtimäki, A.

    1995-01-01

    Germination ability and airborne counts of Scots pine (Pinus sylvestris L.) pollen were studied during the spring of 1993 at Turku in southern Finland (60 degrees 32' N, 22 degrees 28' E) and at Utsjoki in northern Finland (69 degrees 45' N, 27 degrees 01' E). Pollen waas trapped from the beginning of May to the end of June in a high-volume air sampler. Germination tests were performed to determine the in vitro pollen viability of the trapped pollen. Airborne pine pollen counts were obtained from a continuously operating Burkard trap located near each high-volume sampler. When male flowering began, phenological observations were carried out on pollen grains collected in rotored samplers located in pine and spruce stands and open fields near Turku and Utsjoki. In southern Finland, the peak period of pine pollen production was short, lasting for only 3 days, but it accounted for about 80% of the total germinating pine pollen yield for the year. The peak count was on May 20, with over 2000 germinating pollen grains per cubic meter of air. Pollen germination rates of up to 70% were obtained during the week preceding the local pollen peak, and rates reached almost 90% on the peak day. Pollen viability remained at 45 to 65% for 1 week after the peak. There was no significant difference between the pollen counts for day and night, indicating that during the main pollen season, the pollen source was close to Turku. Before the local pollen peak, the counts of living pine pollen were low, indicating that pine pollen transported over long distances was of little ecological importance in 1993 in the Turku area. In northern Finland, the first pollen grains were caught on July 4, and the peak day was July 13. However, no viable pollen was observed during this period, indicating that there was little gene drift from southern to northern Finland in 1993.

  17. Contemporary pollen flow, characterization of the maternal ecological neighbourhood and mating patterns in wild cherry (Prunus avium L.).

    Science.gov (United States)

    Cottrell, J E; Vaughan, S P; Connolly, T; Sing, L; Moodley, D J; Russell, K

    2009-08-01

    Conversion of lowland woodland to agricultural land and resulting fragmentation in Britain has been ongoing since Neolithic times. To counteract this decline, plantations of native species, often based on non-British planting stock, have been established. This may ultimately be detrimental to the integrity of the native gene pool. We explore the genetic and ecological factors influencing the success of components of the local pollen pool, including the effect of a non-native planting on an ancient woodland population of wild cherry. Wild cherry exhibits gametophytic self-incompatibility (GSI) and vegetative reproduction, both of which may be determinants of paternal success. The majority (61%) of the successful pollen originated from within the study site with a maximum pollen transfer distance of 694 m. There was a distinct departure from random mating, with over half the successful pollen originating from trees which occur within 100 m of the mother tree. Self-incompatibility, clonality, tree size and proximity to the mother tree were all found to influence paternal success. Kinship of pollen gametes within a maternal progeny was highest when a mother tree was surrounded by a large number of ramets of a single, compatible clone consisting of large, adult trees. Although the contribution from the non-native plantation is currently low, it is likely that this will increasingly contribute to the progeny of the adjacent ancient population as it matures. The results clearly show that in self-incompatible species, such as P. avium, close neighbours may be pollinated by very different components of the local pollen pool.

  18. High-resolution GPS tracking reveals habitat selection and the potential for long-distance seed dispersal by Madagascan flying foxes Pteropus rufus

    Directory of Open Access Journals (Sweden)

    Ryszard Oleksy

    2015-01-01

    Full Text Available Long-distance seed dispersal can be important for the regeneration of forested habitats, especially in regions where deforestation has been severe. Old World fruit bats (Pteropodidae have considerable potential for long-distance seed dispersal. We studied the movement patterns and feeding behaviour of the endemic Madagascan flying fox Pteropus rufus, in Berenty Reserve, southeast Madagascar. Between July and September 2012 (the dry season nine males and six females were tagged with customised GPS loggers which recorded fixes every 2.5 min between 18.00 and 06.00 h. The combined home range of all of the tagged bats during 86 nights exceeded 58,000 ha. Females had larger home ranges and core foraging areas and foraged over longer distances (average 28.1 km; median 26.7 km than males (average 15.4 km; median 9.5 km. Because the study was conducted during the gestation period, the increased energy requirements of females may explain their greater mean foraging area. Compositional analysis revealed that bats show strong preferences for overgrown sisal (Agave sisalana plantations (a mix of shrub, trees and sisal plants and remnant riverside forest patches. Sisal nectar and pollen were abundant food sources during the tracking period and this probably contributed to the selective use of overgrown sisal plantations. The bats also ate large quantities of figs (Ficus grevei during the study, and dispersed seeds of this important pioneer species. The bats flew at an average speed of 9.13 m/s, perhaps to optimise gliding performance. The study confirms that P. rufus has the potential to be a long-distance seed disperser, and is able to fly over a large area, often crossing cleared parts of its habitat. It potentially plays an important role in the regeneration of threatened forest habitats in this biodiversity hotspot.

  19. Metabolic profile of long-distance migratory flight and stopover in a shorebird

    NARCIS (Netherlands)

    Landys, MM; Piersma, T; Guglielmo, CG; Jukema, J; Ramenofsky, M; Wingfield, JC; Guglielmo, Christopher G.; Wingfield, John C.

    2005-01-01

    Migrating birds often complete long non-stop flights during which body energy stores exclusively support energetic demands. The metabolic correlates of such long-distance travel in free-living migrants are as yet poorly studied. Bar-tailed godwits, Limosa lapponica taymyrensis, undertake a 4500 km f

  20. The design of Gaussian beam zoom system in intermediate and long distance measurement

    Science.gov (United States)

    Wang, Mengcheng; Zhou, Jian

    2016-10-01

    It is well known that laser possesses high brightness, high coherence, good directivity and other unique properties. In many practical applications, it is necessary to get small light spot in intermediate and long distance. Intermediate and long distance laser measurement demands to minimize the spot radius in order to improve the spatial resolution of the system and signal quality. Therefore, the study of Gaussian beam focusing property has high value for practical applications. In order to achieve intermediate and long distance laser measurement, this paper studies the method to adjust Gaussian beam spot diameter within a certain range after a near-field optical system transformation to improve the signal quality. Based on the fundamental characteristics of the Gaussian beam, this paper deduces the theoretical formula for the position and radius of the Gaussian beam waist and measures them by means of the CCD method. Then Matlab is used to simulate the spot diameter in the far field, and by combining numerical simulation results as well as optimizing the structure of the actual optical system, we make the light spot diameter in the target area fit the requirements of the laser velocimeter in intermediate and long distance measurement.

  1. Phenological differences among selected residents and long-distance migrant bird species in central Europe

    Science.gov (United States)

    Bartošová, Lenka; Trnka, Miroslav; Bauer, Zdeněk; Možný, Martin; Štěpánek, Petr; Žalud, Zdeněk

    2014-07-01

    The phenological responses to climate of residents and migrants (short- and long-distance) differ. Although few previous studies have focussed on this topic, the agree that changes in phenology are more apparent for residents than for long-distance migrants. We analysed the breeding times of two selected residents ( Sitta europaea, Parus major) and one long-distance migrant ( Ficedula albicollis) from 1961 to 2007 in central Europe. The timing of the phenophases of all three bird species showed a significant advance to earlier times. Nevertheless, the most marked shift was observed for the long-distance migrant (1.9 days per decade on average in mean laying date with linearity at the 99.9 % confidence level). In contrast, the shifts shown by the residents were smaller (1.6 days for S. europaea and 1.5 days for P. major also on average in mean laying date for both, with linearity at the 95 % confidence level). Spearman rank correlation coefficients calculated for pairs of phenophases of given bird species in 20-year subsamples (e.g. 1961-1980, 1962-1981) showed higher phenological separation between the residents and the migrant. This separation is most apparent after the 1980s. Thus, our results indicate that the interconnections between the studied phenological stages of the three bird species are becoming weaker.

  2. Changing Gender Roles, Shifting Power Balance and Long-distance Migration of Couples

    NARCIS (Netherlands)

    Smits, J.P.J.M.; Mulder, C.H.; Hooimeijer, P.

    2003-01-01

    Long-distance migration of couples requires joint decision-making within the household. The uneven power balance between men and women and traditional gender roles have given rise to the concepts of ‘tied stayer’ (usually the male partner) and ‘tied mover’ (usually the female). Since these concepts

  3. Changing gender roles, shifting power balance and long-distance migration of couples

    NARCIS (Netherlands)

    Smits, J.; Mulder, C.H.; Hooimeijer, P.

    2003-01-01

    Long-distance migration of couples requires joint decision-making within the household. The uneven power balance between men and women and traditional gender roles have given rise to the concepts of 'tied stayer' (usually the male partner) and 'tied mover' (usually the female). Since these concepts

  4. Mode-resolved frequency comb interferometry for high-accuracy long distance measurement

    NARCIS (Netherlands)

    Van den Berg, S.A.; Van Eldik, S.; Bhattacharya, N.

    2015-01-01

    Optical frequency combs have developed into powerful tools for distance metrology. In this paper we demonstrate absolute long distance measurement using a single femtosecond frequency comb laser as a multi-wavelength source. By applying a high-resolution spectrometer based on a virtually imaged phas

  5. Long distance high power optical laser fiber break detection and continuity monitoring systems and methods

    Energy Technology Data Exchange (ETDEWEB)

    Rinzler, Charles C.; Gray, William C.; Faircloth, Brian O.; Zediker, Mark S.

    2016-02-23

    A monitoring and detection system for use on high power laser systems, long distance high power laser systems and tools for performing high power laser operations. In particular, the monitoring and detection systems provide break detection and continuity protection for performing high power laser operations on, and in, remote and difficult to access locations.

  6. Necessity Fuels Creativity: Adapting Long-Distance Collaborative Methods for the Classroom

    Science.gov (United States)

    Sopoci Drake, Katie; Larson, Eliza; Rugh, Rachel; Tait, Barbara

    2016-01-01

    Improved technology has made it possible to virtually bridge distance between dance makers, rendering physical location another choreographic device to be manipulated. Long-distance collaboration as an artistic process is not only a fertile new ground for creation and necessary for many practicing dance artists in the field today, but there is…

  7. Unconditional security proof of long-distance continuous-variable quantum key distribution with discrete modulation.

    Science.gov (United States)

    Leverrier, Anthony; Grangier, Philippe

    2009-05-08

    We present a continuous-variable quantum key distribution protocol combining a discrete modulation and reverse reconciliation. This protocol is proven unconditionally secure and allows the distribution of secret keys over long distances, thanks to a reverse reconciliation scheme efficient at very low signal-to-noise ratio.

  8. Changing gender roles, shifting power balance and long-distance migration of couples

    NARCIS (Netherlands)

    Smits, J.; Mulder, C.H.; Hooimeijer, P.

    2003-01-01

    Long-distance migration of couples requires joint decision-making within the household. The uneven power balance between men and women and traditional gender roles have given rise to the concepts of 'tied stayer' (usually the male partner) and 'tied mover' (usually the female). Since these concepts

  9. Long distance root-shoot signalling in plant-insect community interactions

    NARCIS (Netherlands)

    Soler, R.; Erb, M.; Kaplan, I.

    2013-01-01

    Plants mediate interactions between insects, including leaf- and root-feeders; yet the underlying mechanisms and connection with ecological theory remain unresolved. In this review, based on novel insights into long-distance (i.e., leaf-leaf, root-shoot) defence signalling, we explore the role of ph

  10. Long-Distance and Proximal Romantic Relationship Satisfaction: Attachment and Closeness Predictors

    Science.gov (United States)

    Roberts, Amber; Pistole, M. Carole

    2009-01-01

    Relationship satisfaction was examined in college student long-distance romantic relationships (LDRRs) and geographically proximal romantic relationships (PRRs). LDRR/PRR attachment style proportions and relationship satisfaction were similar. Multiple regression analyses revealed that low attachment avoidance contributed uniquely to high LDRR…

  11. Neuromuscular factors associated with decline in long-distance running performance in master athletes.

    Science.gov (United States)

    Brisswalter, Jeanick; Nosaka, Kazunori

    2013-01-01

    This review focuses on neuromuscular factors that may affect endurance performance in master athletes. During the last decade, due to the rapid increase in the number of master or veteran participants in endurance sporting competitions, many studies attempted to identify metabolic factors associated with the decrease in endurance, especially long-distance running performance with ageing, focusing on decreases in maximal oxygen consumption. However, neuromuscular factors have been less studied despite the well-known phenomena of strength loss with ageing. For master athletes to perform better in long-distance running events, it is important to reduce muscle fatigue and/or muscle damage, to improve locomotion efficiency and to facilitate recovery. To date, no consensus exists that regular endurance training is beneficial for improving locomotion efficiency, reducing muscle fatigue and muscle damage, and enhancing recovery capacity in master athletes. Some recent studies seem to indicate that master athletes have similar muscle damage to young athletes, but they require a longer recovery time after a long-distance running event. Further analyses of these parameters in master athletes require more experimental and practical interest from researchers and coaches. In particular, more attention should be directed towards the capacity to maintain muscle function with training and the role of neuromuscular factors in long-distance performance decline with ageing using a more cellular and molecular approach.

  12. Scheme for Robust Long-Distance Continuous Variable Quantum Key Distribution

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yong-Sheng; QUO Guang-Can

    2006-01-01

    It is shown that the configuration of phase coding for quantum key distribution with single photon can also be used for continuous variable quantum key distribution. Therefore the robust long-distance high-speed quantum key distribution can be achieved with current technology.

  13. Fast long-distance control of spin qubits by photon-assisted cotunneling

    NARCIS (Netherlands)

    Stano, P.; Klinovaja, J.; Braakman, F.R.; Vandersypen, L.M.K.; Loss, D.

    2015-01-01

    We investigate theoretically the long-distance coupling and spin exchange in an array of quantum dot spin qubits in the presence of microwaves. We find that photon-assisted cotunneling is boosted at resonances between photon and energies of virtually occupied excited states and show how to make it

  14. Reliability and accuracy of Cooper's test in male long distance runners

    Directory of Open Access Journals (Sweden)

    J.R. Alvero-Cruz

    2017-06-01

    Conclusions: All together, our results may confirm a good accuracy and reliability of Cooper's test in amateur long distance runners. Also, improvements or impairment lower than 52.2 m must not be associated with exercise training or retraining, since they are below the values of intra-subject reliability.

  15. High-powered conveyor systems: long distance, downhill, open-pit, and high capacity conveyors

    Energy Technology Data Exchange (ETDEWEB)

    Pelzer, H.K.

    1978-01-01

    Paper indicates the conditions under which belt conveyors are superior to other forms of transport, the limitations of these conveyors. Long distance, downhill, open-pit and high capacity conveyor installations are described, including a 60-mile long conveyor in the Sahara.

  16. Broadband IP Stream Transmission Experiments over Global and Long Distance Networks

    Institute of Scientific and Technical Information of China (English)

    Kimio; Oguchi; Tetsuro; Fujii; Atsushi; Takahara; Toshiaki; Miyazaki; Kazuo; Hagimoto; Sadayasu; Ono

    2003-01-01

    Super High Definition (SHD) movies were successfully transmitted as streaming contents at about 300 Mbps for the first time over a long distance IP network (more than 3,000 km), in conjunction with the experimental verification of traffic control and scalable multicast technologies.

  17. Transportation of low-grade thermal energy over long distance by ammonia-water absorption

    Institute of Scientific and Technical Information of China (English)

    MA Qiang; WANG RuZhui; LUO LinGai; XIA ZaiZhong; LIN Peng

    2009-01-01

    This paper presents the importance and the cycle choice for long-distance transportation of low-grade thermal energy, and the thermodynamic and hydrodynamic feasibility of single-effect ammonia-water absorption system for heat or cold transportation over long distance are also involved. A model of a long-distance thermal energy transportation system is built and analyzed, which shows satisfactory and attractive results. When a steam heat source at 12012 is available, the user site can get hot water output at about 55℃ with the thermal COP of about 0.6 and the electric COP of about 100 in winter, and cold water output at about 10~C with the thermal COP of about 0.5 and the electric COP of 50 in summer.A small-size prototype is built to verify the performance analysis. Basically the experimental data show good accordance with the analysis results. The ammonia-water absorption system is a potential prospective solution for the heat or cold transportation over long distance.

  18. Fundamental design of a distributed erbium-doped fiber amplifier for long-distance transmission

    DEFF Research Database (Denmark)

    Rottwitt, Karsten; Bjarklev, Anders Overgaard; Povlsen, Jørn Hedegaard;

    1992-01-01

    Comprehensive theoretical analysis on the design of a distributed erbium-doped fiber amplifier for long-distance transmission has been carried out, using a highly accurate model. The dispersion of the optical fiber as a function of the numerical aperture and the cutoff wavelength is included...

  19. Weak long distance contributions to the neutron and proton electric dipole moments

    NARCIS (Netherlands)

    Bijnens, Johan; Pallante, Elisabetta

    1996-01-01

    We evaluate the long distance weak contribution to the neutron and proton electric dipole moments using an effective Lagrangian framework. We estimate the coefficients needed by a factorization hypothesis and additional assumptions on γ5 terms in the baryon lagrangian. We obtain |dne| ≈ 5 × 10-3

  20. Long Distance Bioenergy Logistics: An assessment of costs and energy consumption for various biomass transport chains

    NARCIS (Netherlands)

    Suurs, R.A.A.

    2002-01-01

    This study gives an analysis of costs and energy consumption, associated with long distance bioenergy transport systems. In order to create the possibility of obtaining an insight in the system’s key factors, a model has been developed, taking into account different production systems,

  1. Long distance high power optical laser fiber break detection and continuity monitoring systems and methods

    Energy Technology Data Exchange (ETDEWEB)

    Rinzler, Charles C.; Gray, William C.; Faircloth, Brian O.; Zediker, Mark S.

    2016-02-23

    A monitoring and detection system for use on high power laser systems, long distance high power laser systems and tools for performing high power laser operations. In particular, the monitoring and detection systems provide break detection and continuity protection for performing high power laser operations on, and in, remote and difficult to access locations.

  2. Metabolic profile of long-distance migratory flight and stopover in a shorebird

    NARCIS (Netherlands)

    Landys, MM; Piersma, T; Guglielmo, CG; Jukema, J; Ramenofsky, M; Wingfield, JC; Guglielmo, Christopher G.; Wingfield, John C.

    2005-01-01

    Migrating birds often complete long non-stop flights during which body energy stores exclusively support energetic demands. The metabolic correlates of such long-distance travel in free-living migrants are as yet poorly studied. Bar-tailed godwits, Limosa lapponica taymyrensis, undertake a 4500 km

  3. Experimental quantification of long distance dispersal potential of aquatic snails in the gut of migratory birds

    NARCIS (Netherlands)

    Van Leeuwen, C.H.A.; Van der Velde, G.; van Lith, B.; Klaassen, M.R.J.

    2012-01-01

    Many plant seeds and invertebrates can survive passage through the digestive system of birds, which may lead to long distance dispersal (endozoochory) in case of prolonged retention by moving vectors. Endozoochorous dispersal by waterbirds has nowadays been documented for many aquatic plant seeds,

  4. Robust Scheme for Long-Distance Teleportation of an Unknown Atomic State

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A scheme is presented for the long-distance teleportation of an unknown atomic state between two separated cavities. The scheme is based on the Raman coupling and cavity decay. In the scheme, the effective atom-cavity coupling strength is much smaller than the cavity decay rate and thus cavities of high quality factor are unnecesssary.

  5. Mesoscale atmospheric transport of ragweed pollen allergens from infected to uninfected areas

    Science.gov (United States)

    Grewling, Ł.; Bogawski, P.; Jenerowicz, D.; Czarnecka-Operacz, M.; Šikoparija, B.; Skjøth, C. A.; Smith, M.

    2016-10-01

    Allergenic ragweed ( Ambrosia spp.) pollen grains, after being released from anthers, can be dispersed by air masses far from their source. However, the action of air temperature, humidity and solar radiation on pollen grains in the atmosphere could impact on the ability of long distance transported (LDT) pollen to maintain allergenic potency. Here, we report that the major allergen of Ambrosia artemisiifolia pollen (Amb a 1) collected in ambient air during episodes of LDT still have immunoreactive properties. The amount of Amb a 1 found in LDT ragweed pollen grains was not constant and varied between episodes. In addition to allergens in pollen sized particles, we detected reactive Amb a 1 in subpollen sized respirable particles. These findings suggest that ragweed pollen grains have the potential to cause allergic reactions, not only in the heavily infested areas but, due to LDT episodes, also in the regions unaffected by ragweed populations.

  6. Risk Factors for Near Miss Incident among Long Distance Bus Drivers in Malaysia

    Directory of Open Access Journals (Sweden)

    Nik Nor Ronaidi NIK MAHDI

    2015-10-01

    Full Text Available Background: Road traffic accident is a worldwide public health issue that has its highest impact on low and middle income countries including Malaysia. Many previous studies concerned on the causality of the actual accidents and little attention were given to near miss incidents. Hence, the current study was designed to determine the prevalence and associated factors for near miss incident among long distance bus drivers in Malaysia.Methods: A cross sectional study was conducted among 517 long distance bus drivers. Data were collected using interview-guided translated and validated Pittsburgh Sleep Quality Index and Manchester Driver Behaviour questionnaire. Multiple logistic regression analysis was performed to determine the significant factors for near miss incident among long distance bus drivers in Malaysia.Results: The prevalence of near miss incident among long distance bus drivers was 37.5% (95% CI: 33.5, 41.8. The significant associated factors for near miss incident were younger age group (ORadj : 1.99; 95% CI: 1.32, 3.01, longer distance travelled per day (ORadj : 2.34; 95% CI: 1.52, 3.60, sleep disturbances (ORadj : 1.74; 95% CI: 1.19, 2.54 and errors in driving behaviour (ORadj : 1.31; 95% CI: 1.23, 1.39.Conclusion: Self-reported near miss incidents were relatively high among long distance bus drivers in Malaysia. This issue should be taken seriously and preventive action should consider the significant human factors such as younger age group, errors in driving behaviours, sleep disturbances as well as occupational factors like distance travelled per day. Keywords: Road traffic accident, Near miss, Bus drivers, Malaysia 

  7. Long-Distance Communication and Signal Amplification in Systemic Acquired Resistance

    Directory of Open Access Journals (Sweden)

    Jyoti eShah

    2013-02-01

    Full Text Available Systemic acquired resistance (SAR is an inducible defense mechanism in plants that confers enhanced resistance against a variety of pathogens. SAR is activated in the uninfected systemic (distal organs in response to a prior (primary infection elsewhere in the plant. SAR is associated with the activation of salicylic acid (SA signaling and the priming of defense responses for robust activation in response to subsequent infections. The activation of SAR requires communication by the primary infected tissues with the distal organs. The vasculature functions as a conduit for the translocation of factors that facilitate long-distance intra-plant communication. In recent years, several metabolites putatively involved in long-distance signaling have been identified. These include the methyl ester of SA (MeSA, the abietane diterpenoid dehydroabietinal (DA, the dicarboxylic acid azelaic acid (AzA, and a glycerol-3-phosphate (G3P-dependent factor. Long-distance signaling by some of these metabolites also requires the lipid-transfer protein DIR1 (DEFECTIVE IN INDUCED RESISTANCE 1. The relative contribution of these factors in long-distance signaling is likely influenced by environmental conditions, for example light. In the systemic leaves, the AGD2-LIKE DEFENSE RESPONSE PROTEIN1 (ALD1-dependent production of the lysine catabolite pipecolic acid (Pip, FLAVIN-DEPENDENT MONOOXYGENASE1 (FMO1 signaling, as well as SA synthesis and downstream signaling are required for the activation of SAR. This review summarizes the involvement and interaction between long-distance SAR signals and details the recently discovered role of Pip in defense amplification and priming that allows plants to acquire immunity at the systemic level. Recent advances in SA signaling and perception are also highlighted.

  8. Identification a coat protein region of cucumber mosaic virus (CMV) essential for long-distance movement in cucumber.

    Science.gov (United States)

    Salánki, Katalin; Kiss, László; Gellért, Akos; Balázs, Ervin

    2011-12-01

    To characterise the long-distance movement determinant of cucumoviral coat proteins (CPs), five mutants were engineered into the CMV CP bearing the corresponding tomato aspermy virus (TAV) loops exposed on the surface of the virion. Both viruses can move long-distance in Nicotiana clevelandii, but only CMV can move long-distance in cucumber. Investigation of the CMV chimeras identified three amino acids of the βB-βC loop that were essential for the CMV long-distance movement in cucumber. Introducing these mutations into the TAV CP was not sufficient for long-distance movement, indicating that this is not the sole region causing long-distance movement deficiency.

  9. Imaging long distance propagating calcium signals in intact plant leaves with the BRET-based GFP-Aequorin reporter

    Directory of Open Access Journals (Sweden)

    Tou Cheu eXiong

    2014-02-01

    Full Text Available Calcium (Ca2+ is a second messenger involved in many plant signalling processes. Biotic and abiotic stimuli induce Ca2+ signals within plant cells, which, when decoded, enable these cells to adapt in response to environmental stresses. Multiple examples of Ca2+ signals from plants containing the fluorescent yellow cameleon sensor (YC have contributed to the definition of the Ca2+ signature in some cell types such as root hairs, pollen tubes and guard cells. YC is, however, of limited use in highly autofluorescent plant tissues, in particular mesophyll cells. Alternatively, the bioluminescent reporter aequorin enables Ca2+ imaging in the whole plant, including mesophyll cells, but this requires specific devices capable of detecting the low amounts of emitted light. Another type of Ca2+ sensor, referred to as GFP-aequorin (G5A, has been engineered as a chimeric protein, which combines the two photoactive proteins from the jellyfish Aequorea victoria, the green fluorescent protein (GFP and the bioluminescent protein aequorin. The Ca2+-dependent light-emitting property of G5A is based on a bioluminescence resonance energy transfer (BRET between aequorin and GFP. G5A has been used for over 10 years for enhanced in vivo detection of Ca2+ signals in animal tissues.Here, we apply G5A in Arabidopsis and show that G5A greatly improves the imaging of Ca2+ dynamics in intact plants. We describe a simple method to image Ca2+ signals in autofluorescent leaves of plants with a cooled charge-coupled device (cooled CCD camera. We present data demonstrating how plants expressing the G5A probe can be powerful tools for imaging of Ca2+ signals. It is shown that Ca2+ signals propagating over long distances can be visualized in intact plant leaves and are visible mainly in the veins.

  10. Oil collecting bees and Byrsonima cydoniifolia A. Juss. (Malpighiaceae) interactions: the prevalence of long-distance cross pollination driving reproductive success.

    Science.gov (United States)

    Sazan, Morgana S; Bezerra, Antonio Diego M; Freitas, Breno M

    2014-03-01

    Oil-collecting bees are the natural pollinators of oil-flower plants, but little is known about the pollination process and the effectiveness of their pollination service to the reproductive success of their host plants. In species of Byrsonima the reproductive system have been described as auto-compatible or self-incompatible. We studied the reproductive system of Byrsonima cydoniifolia, the fructification by means of short, medium and long-distance cross pollinations, the morphology and floral biology and the pollination interactions with species of oil-collecting bees. By means of controlled pollinations we found self-incompatibility caused by abortion of most self-pollinated flowers and demonstrated that the prevailing cross pollination ensuring the reproductive success of B. cydoniifolia is the long-distance cross pollination and Centridini bees; Epicharis nigrita, particularly, are the pollinators promoting the gene flow between genetically distinct populations.

  11. Multiple-Language Translation System Focusing on Long-distance Medical and Outpatient Services

    Directory of Open Access Journals (Sweden)

    Rena Aierken

    2016-10-01

    Full Text Available For people living in the countryside, an effective long-distance medical and health service is very important. People living in western China, especially, require convenient communication in their native language with doctors working in a modern city. To address this problem, a multiple-language translation system for long-distance medical and outpatient services is discussed. This system initially provides a table containing basic information including disease names and symptoms for different medical classifications, and then translates the sentences selected from the table automatically using a machine translation system. Finally, a PDF file is created for the doctor and the patient. In this paper, the system construction and evaluation of the machine translation are introduced.

  12. Process for the Φ130 sapphire window element with long distance and high resolution

    Science.gov (United States)

    Xu, Zengqi; Su, Ying; Lei, Jianli; Guo, Rui; Zhang, Feng; Guo, Xinlong; Liu, Xuanmin; Sun, Taohui

    2016-10-01

    With the process test for the choice of materials, the test materials and the molds, the abrasives, the temperature and the different machining process monitoring parameters of the polishing machine, the process method and the quality control technology were figured out for the Φ130 sapphire window element with long distance and high resolution (hereinafter referred to as window element), meantime, the optimum process condition was determined to machine the element. The results were that the high resolution imaging window was processed with the surface roughness Ra of 0.639nm, the transmission distortion of λ/10 (λ=632.8nm), the parallel error of 5″, the resolution of 1.47″ and the focal length of 5 km, which can satisfy the imaging requirements better for the military photoelectric device for sapphire window with long distance and high resolution.

  13. Long distance related stressors and coping behaviors in parents of children with cancer.

    Science.gov (United States)

    Aitken, T J; Hathaway, G

    1993-01-01

    This descriptive comparative study addresses long distance related stress and coping behaviors of 53 parents of children with cancer. The purpose of the study was to determine the differences in the stress and coping behaviors of parents living 100 miles from the tertiary treatment center compared with those who live less than 100 miles from the center. The theoretical framework used was Lazarus' theory on stress and coping. The study participants were from several Pediatric Oncology Group member institutions. The parents completed Hymovich's Parent Perception Inventory and a demographic data sheet. Parametric (one-tailed t-test) and nonparametric (Mann-Whitney and chi-squared tests) were included in the statistical analysis. The results showed significant differences in demographic data, concerns, beliefs/feelings, and coping. Implications for the pediatric oncology treatment team include specific interventions that will improve the quality of care for the children/parents who live a long distance from the tertiary treatment center.

  14. Experimental Long-Distance Decoy-State Quantum Key Distribution Based On Polarization Encoding

    CERN Document Server

    Peng, C Z; Ma, H X; Pan, J W; Wang, X B; Yang, D; Yang, T; Yin, H; Zeng, H P; Zhang, J; Gao, Wei-Bo; Ma, Huai-Xin; Pan, Jian-Wei; Peng, Cheng-Zhi; Wang, Xiang-Bin; Yang, Dong; Yang, Tao; Yin, Hao; Zeng, He-Ping; Zhang, Jun

    2006-01-01

    We demonstrate the decoy-state quantum key distribution (QKD) with one-way quantum communication in polarization space over 75 km. So far, our experimental implementation is the only one that really offers the unconditionally secure final keys among all the implementations of long-distance QKD with weak coherent states. We use 3 different intensities of 0, 0.2 and 0.6 for the pulses of source in our experiment. In order to eliminate the influences of polarization mode dispersion in the long-distance single-mode optical fiber, an automatic polarization compensation system is utilized to implement the active compensation. Only one detector is used in our experiment. The secure distance can be raised to 120 km given 4 detectors.

  15. Study on the Technology of Supplying Water Safely by Long-Distance Pipeline

    Institute of Scientific and Technical Information of China (English)

    CHEN Yanbo; YU Taipin; LIU Junhua; ZHAO Hongbin

    2008-01-01

    The extensively built long-distance water transmission pipelines have become the main water sources for urban areas.To ensure the reliability and safety of the water supply,from the viewpoint of overall management, it would be necessary to establish a system of information management for the pipeline.The monitoring,calculating and analyzing functions of the system serve to give controlling instructions and safe operating rules to the automatic equipment and technician, making sure the resistance coefficient distribution along the pipeline is reasonable;the hydraulic state transition is smooth when operating conditions change or water supply accidents occur,avoiding the damage of water hammer.This paper covered the composition structures of the information management system of long-distance water transmission pipelines and the functions of the subsystems, and finally elaborated on the approaches and steps ofbuilding a mathematics model for the analysis of dynamic hydraulic status.

  16. The Saudi clinical practice guideline for the prophylaxis of venous thromboembolism in long-distance travelers

    Science.gov (United States)

    Al-Hameed, Fahad M.; Al-Dorzi, Hasan M.; Abdelaal, Mohamed A.; Alaklabi, Ali; Bakhsh, Ebtisam; Alomi, Yousef A.; Baik, Mohammad Al; Aldahan, Salah; Schünemann, Holger; Brozek, Jan; Wiercioch, Wojtek; Darzi, Andrea J.; Waziry, Reem; Akl, Elie A.

    2017-01-01

    Venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), is a preventable disease. Long distant travelers are prone to variable degree to develop VTE. However, the low risk of developing VTE among long-distance travelers and which travelers should receive VTE prophylaxis, and what prophylactic measures should be used led us to develop these guidelines. These clinical practice guidelines are the result of an initiative of the Ministry of Health of the Kingdom of Saudi Arabia involving an expert panel led by the Saudi Association for Venous Thrombo Embolism (a subsidiary of the Saudi Thoracic Society). The McMaster University Guideline working group provided the methodological support. The expert panel identified 5 common questions related to the thromboprophylaxis in long-distance travelers. The corresponding recommendations were made following the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach. PMID:28042639

  17. Long-distance super-resolution imaging assisted by enhanced spatial Fourier transform.

    Science.gov (United States)

    Tang, Heng-He; Liu, Pu-Kun

    2015-09-07

    A new gradient-index (GRIN) lens that can realize enhanced spatial Fourier transform (FT) over optically long distances is demonstrated. By using an anisotropic GRIN metamaterial with hyperbolic dispersion, evanescent wave in free space can be transformed into propagating wave in the metamaterial and then focused outside due to negative-refraction. Both the results based on the ray tracing and the finite element simulation show that the spatial frequency bandwidth of the spatial FT can be extended to 2.7k(0) (k(0) is the wave vector in free space). Furthermore, assisted by the enhanced spatial FT, a new long-distance (in the optical far-field region) super-resolution imaging scheme is also proposed and the super resolved capability of λ/5 (λ is the wavelength in free space) is verified. The work may provide technical support for designing new-type high-speed microscopes with long working distances.

  18. Significance of self magnetic field in long-distance collimation of laser-generated electron beams

    CERN Document Server

    Chen, Shi; Niu, Yifei; Dan, Jiakun; Chen, Ziyu; Li, Jianfeng

    2014-01-01

    Long-distance collimation of fast electron beams generated by laser-metallic-wire targets has been observed in recent experiments, while the mechanism behind this phenomenon remains unclear. In this work, we investigate in detail the laser-wire interaction processes with a simplified model and Classical Trajectory Monte Carlo simulations, and demonstrate the significance of the self magnetic fields of the beams in the long-distance collimation. Good agreements of simulated image plate patterns with various experiments and detailed analysis of electron trajectories show that the self magnetic fields provide restoring force that is critical for the beam collimation. By studying the wire-length dependence of beam divergence in certain experiments, we clarify that the role of the metallic wire is to balance the space-charge effect and thus maintain the collimation.

  19. Pollen gene flow, male reproductive success, and genetic correlations among offspring in a northern red oak (Quercus rubra L.) seed orchard.

    Science.gov (United States)

    Alexander, Lisa; Woeste, Keith

    2017-01-01

    Northern red oak is a high-value hardwood used for lumber, furniture and veneer. Intensively managed northern red oak seed orchards are required to obtain genetic gain for trait improvement. Data from conifer seed orchards and natural and managed stands of hardwood trees have shed light on the distance over which pollen can move, and underscore the need for managerial attention to seed orchard design, placement, and maintenance. We used eleven microsatellite markers to investigate pollen gene flow, female mate choice, and male reproductive success in a clonal seed orchard of northern red oak based on paternity analysis of seed orchard offspring in progeny tests. Nearly all (93%) offspring were sired by a male parent within the seed orchard. The mean number of male parents per year was 69.5, or 47.6% of all clones in the seed orchard. Female clones in the early phenology group had more offspring sired from extra-orchard pollen (13%) than clones in the intermediate (5%) and late (1%) phenology groups. Distance was the largest influence on pollination success, and pollination occurred most often by male trees in the same subline as the maternal tree. Males in the early phenology group sired more offspring overall in the progeny pool and more offspring per mother tree than males in the intermediate or late phenology groups. Average genetic correlations among all OP progeny ranged between 0.2557 and 0.3529 with a mean of 0.28±0.01. The importance of progeny test genotyping for northern red oak improvement likely is increasing with the demand for improved varieties. The current study demonstrated the feasibility of post hoc assembly of full-sib families for genetic analysis.

  20. Pollen gene flow, male reproductive success, and genetic correlations among offspring in a northern red oak (Quercus rubra L.) seed orchard

    Science.gov (United States)

    Woeste, Keith

    2017-01-01

    Northern red oak is a high-value hardwood used for lumber, furniture and veneer. Intensively managed northern red oak seed orchards are required to obtain genetic gain for trait improvement. Data from conifer seed orchards and natural and managed stands of hardwood trees have shed light on the distance over which pollen can move, and underscore the need for managerial attention to seed orchard design, placement, and maintenance. We used eleven microsatellite markers to investigate pollen gene flow, female mate choice, and male reproductive success in a clonal seed orchard of northern red oak based on paternity analysis of seed orchard offspring in progeny tests. Nearly all (93%) offspring were sired by a male parent within the seed orchard. The mean number of male parents per year was 69.5, or 47.6% of all clones in the seed orchard. Female clones in the early phenology group had more offspring sired from extra-orchard pollen (13%) than clones in the intermediate (5%) and late (1%) phenology groups. Distance was the largest influence on pollination success, and pollination occurred most often by male trees in the same subline as the maternal tree. Males in the early phenology group sired more offspring overall in the progeny pool and more offspring per mother tree than males in the intermediate or late phenology groups. Average genetic correlations among all OP progeny ranged between 0.2557 and 0.3529 with a mean of 0.28±0.01. The importance of progeny test genotyping for northern red oak improvement likely is increasing with the demand for improved varieties. The current study demonstrated the feasibility of post hoc assembly of full-sib families for genetic analysis. PMID:28166543

  1. Pollen flow in fragmented landscapes maintains genetic diversity following stand-replacing disturbance in a neotropical pioneer tree, Vochysia ferruginea Mart.

    Science.gov (United States)

    Davies, S J; Cavers, S; Finegan, B; White, A; Breed, M F; Lowe, A J

    2015-08-01

    In forests with gap disturbance regimes, pioneer tree regeneration is typically abundant following stand-replacing disturbances, whether natural or anthropogenic. Differences in pioneer tree density linked to disturbance regime can influence pollinator behaviour and impact on mating patterns and genetic diversity of pioneer populations. Such mating pattern shifts can manifest as higher selfing rates and lower pollen diversity in old growth forest populations. In secondary forest, where more closely related pollen donors occur, an increase in biparental inbreeding is a potential problem. Here, we investigate the consequences of secondary forest colonisation on the mating patterns and genetic diversity of open-pollinated progeny arrays for the long-lived, self-compatible pioneer tree, Vochysia ferruginea, at two Costa Rican sites. Five microsatellite loci were screened across adult and seed cohorts from old growth forest with lower density, secondary forest with higher density, and isolated individual trees in pasture. Progeny from both old growth and secondary forest contexts were predominantly outcrossed (tm=1.00) and experienced low levels of biparental inbreeding (tm-ts=0.00-0.04). In contrast to predictions, our results indicated that the mating patterns of V. ferruginea are relatively robust to density differences between old growth and secondary forest stands. In addition, we observed that pollen-mediated gene flow possibly maintained the genetic diversity of open-pollinated progeny arrays in stands of secondary forest adults. As part of a natural resource management strategy, we suggest that primary forest remnants should be prioritised for conservation to promote restoration of genetic diversity during forest regeneration.

  2. Long-distance behavior of temperature correlation functions in the one-dimensional Bose gas

    Energy Technology Data Exchange (ETDEWEB)

    Kozlowski, K.K. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Maillet, J.M. [UMR 5672 du CNRS, ENS Lyon (France). Lab. de Physique; Slavnov, N.A. [Steklov Mathematical Institute, Moscow (Russian Federation)

    2010-12-15

    We describe a Bethe ansatz based method to derive, starting from a multiple integral representation, the long-distance asymptotic behavior at finite temperature of the density-density correlation function in the interacting onedimensional Bose gas. We compute the correlation lengths in terms of solutions of non-linear integral equations of the thermodynamic Bethe ansatz type. Finally, we establish a connection between the results obtained in our approach with the correlation lengths stemming from the quantum transfer matrix method. (orig.)

  3. Hyperbolic waveguide for long-distance transport of near-field heat flux

    Science.gov (United States)

    Messina, Riccardo; Ben-Abdallah, Philippe; Guizal, Brahim; Antezza, Mauro; Biehs, Svend-Age

    2016-09-01

    Heat flux exchanged between two hot bodies at subwavelength separation distances can exceed the limit predicted by the blackbody theory. However, this super-Planckian transfer is restricted to these separation distances. Here we demonstrate the possible existence of a super-Planckian transfer at arbitrary large separation distances if the interacting bodies are connected in the near field with weakly dissipating hyperbolic waveguides. This result opens the way to long-distance transport of near-field thermal energy.

  4. Narratives of Psychosocial Response to Microtrauma Injury among Long-Distance Runners

    OpenAIRE

    Hayley C. Russell; Wiese-Bjornstal, Diane M.

    2015-01-01

    Athletes with microtrauma or overuse injuries resulting from an accumulation of repeated small forces may differ from athletes with macrotrauma or acute injuries in their psychosocial responses because of the unique challenges presented by these insidious-onset and often chronic injuries. Our purpose was to use narrative inquiry to examine the psychosocial experiences and responses of 10 long-distance runners who had experienced microtrauma injuries. Qualitative data analysis of interview dat...

  5. The Distant Heart: Mediating Long-Distance Relationships through Connected Computational Jewelry

    OpenAIRE

    Silina, Yulia; Haddadi, Hamed

    2015-01-01

    In the world where increasingly mobility and long-distance relationships with family, friends and loved-ones became commonplace, there exists a gap in intimate interpersonal communication mediated by technology. Considering the advances in the field of mediation of relationships through technology, as well as prevalence of use of jewelry as love-tokens for expressing a wish to be remembered and to evoke the presence of the loved-one, developments in the new field of computational jewelry offe...

  6. Superconducting cables: Long distance energy transmission. (Latest citations from the NTIS bibliographic database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-06-01

    The bibliography contains citations concerning the design, development, and evaluation of superconducting cables and power transmission lines for long distance energy transmission. Topics include methods of cryogenic refrigeration and electrical insulation, fabrication and development of niobium alloy conductors, energy loss analysis, and dielectric design of superconducting power transmission systems. Government research reports on superconducting technology for electric power transmission and distribution are also reviewed.(Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  7. Consuls, Corsairs, and Commerce : The Swedish Consular Service and Long-distance Shipping

    OpenAIRE

    Müller, Leos

    2004-01-01

    Eighteenth-century Swedish consuls played an important role in the establishment of Sweden’s trade links with the Mediterranean and, after 1780, with the ‘West Indies’ – the latter including the young American republic. However, historians have paid scant attention to their role. Consuls, Corsairs, and Commerce attempts to fill this gap. The consular service is analysed as part of an institutional framework, helping to reduce the transaction costs of Swedish actors in long-distance trade and ...

  8. Addition of long-distance heart procurement promotes changes in heart transplant waiting list status

    Directory of Open Access Journals (Sweden)

    Fernando Antibas Atik

    2014-09-01

    Full Text Available Objective: Evaluate the addition of long-distance heart procurement on a heart transplant program and the status of heart transplant recipients waiting list. Methods: Between September 2006 and October 2012, 72 patients were listed as heart transplant recipients. Heart transplant was performed in 41 (57%, death on the waiting list occurred in 26 (36% and heart recovery occurred in 5 (7%. Initially, all transplants were performed with local donors. Long-distance, interstate heart procurement initiated in February 2011. Thirty (73% transplants were performed with local donors and 11 (27% with long-distance donors (mean distance=792 km±397. Results: Patients submitted to interstate heart procurement had greater ischemic times (212 min ± 32 versus 90 min±18; P<0.0001. Primary graft dysfunction (distance 9.1% versus local 26.7%; P=0.23 and 1 month and 12 months actuarial survival (distance 90.1% and 90.1% versus local 90% and 86.2%; P=0.65 log rank were similar among groups. There were marked incremental transplant center volume (64.4% versus 40.7%, P=0.05 with a tendency on less waiting list times (median 1.5 month versus 2.4 months, P=0.18. There was a tendency on reduced waiting list mortality (28.9% versus 48.2%, P=0.09. Conclusion: Incorporation of long-distance heart procurement, despite being associated with longer ischemic times, does not increase morbidity and mortality rates after heart transplant. It enhances viable donor pool, and it may reduce waiting list recipient mortality as well as waiting time.

  9. Demand Routing with ASE Impairment Consideration in Long Distance Optical Networks

    Science.gov (United States)

    Dai, Rui; Yang, Hongchang; Xu, Liang

    2016-03-01

    In this paper, a heuristic algorithm that considers ASE (Amplified Spontaneous Emission) noise impairment is developed for demand routing in long distance optical networks. Amplifier span constraints, determined by ASE noise impairment, are presented to constrain the maximal transparent reach of a lightpath. Problem formulation and heuristic algorithms are given. Simulation demonstrates that each demand stream is guaranteed to be successfully routed, and network resources (wavelength channels and transceivers) are effectively utilized.

  10. Viewpoint of animal welfare organisations on the long distance transportation of farm animals

    OpenAIRE

    Leah Garcés; Victoria Cussen; Hugh Wirth

    2008-01-01

    The World Society for the Protection of Animals (WSPA) describes the viewpoint of non-governmental organisations (NGOs) involved in the welfare of farm animals undergoing long distance transportation. The guiding principle is that the potential for poor animal welfare increases with the distance and duration of travel. Thus, farm animals should be slaughtered as close to their farm of origin as possible and trade in live animals for slaughter should be replaced with a trade in meat only. The ...

  11. Centenary of long distance railway electrification in Germany; 100 Jahre Fernbahnelektrifizierung in Deutschland

    Energy Technology Data Exchange (ETDEWEB)

    Grassmann, Siegfried [DB Bahn Fernverkehr AG, Muenchen (Germany). Regionalbereich Sued; Scherrans, Thomas [IFB Institut fuer Bahntechnik GmbH, Dresden (Germany); Glanert, Peter

    2011-04-15

    Starting of electric test operation on the railway line Dessau - Bitterfeld on January 18{sup th} 1911 was the hour of birth of electric long distance railway traction in Germany with low frequency single phase a. c. Construction of traction power supply installations and putting into service of the electric locomotives are pioneering works of technical history. Extension was initiated just during first test period, but eruption of World War I stopped the project abruptly. (orig.)

  12. Long-distance electron transfer by cable bacteria in aquifer sediments

    OpenAIRE

    Müller, Hubert; BOSCH, Julian; Griebler, Christian; Damgaard, Lars Riis; Nielsen, Lars Peter; Lueders, Tillmann; Meckenstock, Rainer U.

    2016-01-01

    The biodegradation of organic pollutants in aquifers is often restricted to the fringes of contaminant plumes where steep countergradients of electron donors and acceptors are separated by limited dispersive mixing. However, long-distance electron transfer (LDET) by filamentous ‘cable bacteria' has recently been discovered in marine sediments to couple spatially separated redox half reactions over centimeter scales. Here we provide primary evidence that such sulfur-oxidizing cable bacteria ca...

  13. Impact of an HIV prevention intervention on condom use among long distance truckers in India.

    Science.gov (United States)

    Juneja, Sachin; Rao Tirumalasetti, Vasudha; Mishra, Ram Manohar; Sethu, Shekhar; Singh, Indra Ramyash

    2013-03-01

    This paper examines the impact of three components of an HIV prevention program (mid-media, interpersonal communication, and project-run clinics) on consistent condom use by long distance truckers with paid and non-paid female partners in India. Data from 2,723 long distance truckers were analyzed using the propensity score matching approach. Based on utilization of services, the following categories of intervention exposure were derived: no exposure, exposure only to mid-media, exposure only to mid-media and interpersonal communication, exposure only to mid-media and project-run clinics, and exposure to all three intervention components. Compared to those who were not exposed to any intervention, exposure to mid-media alone increased consistent condom use with paid female partners by about ten percent. Exposure to mid-media and visits to project-run clinics increased consistent condom use with non-paid female partners by 26 %. These findings suggest that mid-media events and clinics were the most effective package of services to increase consistent condom use among the long distance truckers.

  14. Study on the long-distance target apperception techniques for underwater vehicles

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The limited physical size for autonomous underwater vehicles (AUV)or unmanned underwater vehicles (UUV)makes it difficult to acquire enough space gain for localizing long-distance targets.A new technique about long-distance target apperception with passive synthetic aperture array for underwater vehicles is presented.First,a synthetic aperture-processing algorithm based on the FFT transform in the beam space(BSSAP)is introduced.Then,the study on the flank array passive long-distance apperception techniques in the frequency scope of 11-18 kHz is implemented from the view of improving array gains,detection probability and augmenting detected range under a certain sea environment.The results show that the BSSAP algorithm can extend the aperture effectively and improve detection probability.Because of the augment of the transmission loss,the detected range has the trend of decline with the increase of frequency under the same target source level.The synthesized array could improve the space gain by nearly 7 dB and SNR is increased by about 5 dB.The detected range is enhanced to nearly 2 km under the condition of 108-118 dB of the target source level for AUV system in measurement interval of nearly 1 s.

  15. Vibrational long-distance communication in the termites Macrotermes natalensis and Odontotermes sp.

    Science.gov (United States)

    Hager, Felix A; Kirchner, Wolfgang H

    2013-09-01

    Fungus-growing higher termites build long subterranean galleries that lead outwards from the nest to foraging sites. When soldiers are disturbed, they tend to drum with their heads against the substrate and thereby create vibrational alarm signals. The present study aimed at describing these acoustic signals, how they are elicited, produced and perceived, and how these signals propagate within the galleries and nests over long distances in two termite species of the Southern African savannah, Macrotermes natalensis and an Odontotermes sp. The signals consist of trains of pulses with a pulse repetition rate of 10-20 Hz. The galleries have physical features that promote vibrational communication and are used as channels for long-distance communication. In M. natalensis, the signal propagation velocity is ~130 m s(-1) and the signals are attenuated by ~0.4 dB per centimetre distance. Nestmates are extremely sensitive to these vibrations with a behavioural threshold amplitude of 0.012 m s(-2). Workers respond by a fast retreat into the nest and soldiers are recruited to the source of vibration. Soldiers also start to drum with a reaction time of about 0.3 s, thereby amplifying the intensity of the signal. This social long-distance communication through chains of signal-reamplifying termites results in a relatively slow propagation (1.3 m s(-1)) of the signal without decrement over distances of several metres.

  16. The Effect of a 20 km Run on Appetite Regulation in Long Distance Runners

    Directory of Open Access Journals (Sweden)

    Chihiro Kojima

    2016-10-01

    Full Text Available The purpose of the present study was to investigate appetite-related hormonal responses and energy intake after a 20 km run in trained long distance runners. Twenty-three male long-distance runners completed two trials: either an exercise trial consisting of a 20 km outdoor run (EX or a control trial with an identical period of rest (CON. Blood samples were collected to determine plasma acylated ghrelin, peptide YY3-36 (PYY3-36 and other hormonal and metabolite concentrations. Energy intake during a buffet test meal was also measured 30 min after the exercise or rest periods. Although plasma acylated ghrelin concentrations were significantly decreased after the 20 km run (p < 0.05, plasma PYY3-36 did not change significantly following exercise. Absolute energy intake during the buffet test meal in EX (1325 ± 55 kcal was significantly lower than that in CON (1529 ± 55 kcal, and there was a relatively large degree of individual variability for exercise-induced changes in energy intake (−40.2% to 12.8%. However, exercise-induced changes in energy intake were not associated with plasma acylated ghrelin or PYY3-36 responses. The results demonstrated that a 20 km run significantly decreased plasma acylated ghrelin concentrations and absolute energy intake among well-trained long distance runners.

  17. Voluntary counseling and willingness to screen among Nigerian long distance truck drivers

    Directory of Open Access Journals (Sweden)

    P N Aniebue

    2011-01-01

    Full Text Available Background: Voluntary counseling and testing (VCT is an important preventive strategy in the control of HIV/AIDS and Long distance truck drivers (LDTD have been identified as an important group in the transmission of HIV/AIDS. This study aims to assess knowledge and perception of Nigerian long distance truck drivers on HIV/AIDS, voluntary counseling and testing and their willingness to undergo HIV screening. Materials and Methods: One hundred and ninety seven LDTD in Enugu, Nigeria were surveyed using pre tested structured questionnaires. Results: Awareness of HIV/AIDS was high (94.9% amongst the drivers and the media was their commonest source of information. Similarly the awareness of VCT was high (94.4%. One hundred and eight (54.8% respondents were willing to undergo HIV screening test if offered freely and 86 (43.7% others have previously been screened. Educational status was a significant determinant of willingness to undergo HIV screening p<0.05. The reasons for screening were mainly doctors′ recommendation (19.3% and voluntary self screening (18.8%. The commonest reasons for not wanting to undergo screening were the feeling of not being at risk (27.9%, fear of a positive result (10.2% and cost of screening test (9.6%. Conclusion: There is a critical need to improve HIV screening participation amongst Long distance drivers in Nigeria.

  18. Feasibility of long-distance heart rate monitoring using transmittance photoplethysmographic imaging (PPGI)

    Science.gov (United States)

    Amelard, Robert; Scharfenberger, Christian; Kazemzadeh, Farnoud; Pfisterer, Kaylen J.; Lin, Bill S.; Clausi, David A.; Wong, Alexander

    2015-10-01

    Photoplethysmography (PPG) devices are widely used for monitoring cardiovascular function. However, these devices require skin contact, which restricts their use to at-rest short-term monitoring. Photoplethysmographic imaging (PPGI) has been recently proposed as a non-contact monitoring alternative by measuring blood pulse signals across a spatial region of interest. Existing systems operate in reflectance mode, many of which are limited to short-distance monitoring and are prone to temporal changes in ambient illumination. This paper is the first study to investigate the feasibility of long-distance non-contact cardiovascular monitoring at the supermeter level using transmittance PPGI. For this purpose, a novel PPGI system was designed at the hardware and software level. Temporally coded illumination (TCI) is proposed for ambient correction, and a signal processing pipeline is proposed for PPGI signal extraction. Experimental results show that the processing steps yielded a substantially more pulsatile PPGI signal than the raw acquired signal, resulting in statistically significant increases in correlation to ground-truth PPG in both short- and long-distance monitoring. The results support the hypothesis that long-distance heart rate monitoring is feasible using transmittance PPGI, allowing for new possibilities of monitoring cardiovascular function in a non-contact manner.

  19. Efficient utilization of wind power: Long-distance transmission or local consumption?

    Science.gov (United States)

    Sun, Yuanzhang; Ma, Xiyuan; Xu, Jian; Bao, Yi; Liao, Siyang

    2017-09-01

    Excess wind power produced in wind-intensive areas is normally delivered to remote load centers via long-distance transmission lines. This paper presents a comparison between long-distance transmission, which has gained popularity, and local energy consumption, in which a fraction of the generated wind power can be locally consumed by energy-intensive industries. First, the challenges and solutions to the long-distance transmission and local consumption of wind power are presented. Then, the two approaches to the utilization of wind power are compared in terms of system security, reliability, cost, and capability to utilize wind energy. Finally, the economic feasibility and technical feasibility of the local consumption of wind power are demonstrated by a large and isolated industrial power system, or supermicrogrid, in China. The coal-fired generators together with the short-term interruptible electrolytic aluminum load in the supermicrogrid are able to compensate for the intermittency of wind power. In the long term, the transfer of high-energy-consumption industries to wind-rich areas and their local consumption of the available wind power are beneficial.

  20. Long-distance dispersal via ocean currents connects Omani clownfish populations throughout entire species range.

    Directory of Open Access Journals (Sweden)

    Stephen D Simpson

    Full Text Available Dispersal is a crucial ecological process, driving population dynamics and defining the structure and persistence of populations. Measuring demographic connectivity between discreet populations remains a long-standing challenge for most marine organisms because it involves tracking the movement of pelagic larvae. Recent studies demonstrate local connectivity of reef fish populations via the dispersal of planktonic larvae, while biogeography indicates some larvae must disperse 100-1000 s kilometres. To date, empirical measures of long-distance dispersal are lacking and the full scale of dispersal is unknown. Here we provide the first measure of long-distance dispersal in a coral reef fish, the Omani clownfish Amphiprion omanensis, throughout its entire species range. Using genetic assignment tests we demonstrate bidirectional exchange of first generation migrants, with subsequent social and reproductive integration, between two populations separated by over 400 km. Immigration was 5.4% and 0.7% in each region, suggesting a biased southward exchange, and matched predictions from a physically-coupled dispersal model. This rare opportunity to measure long-distance dispersal demonstrates connectivity of isolated marine populations over distances of 100 s of kilometres and provides a unique insight into the processes of biogeography, speciation and adaptation.

  1. From short to long distances with Gell-Mann--Low Renormalization group

    Science.gov (United States)

    Dunjko, Vanja; Olshanii, Maxim

    2004-05-01

    Computing correlation functions is an important and formidable problem of many-body physics. For 1D gapless systems, Haldane's theory gives exponents of large distance expansions, model details entering through speed of sound. The prefactors depend on high-energy cutoffs, and it is unclear which model-dependent parameters set them. ..We present a method very well-suited for the approximate computation of the leading order prefactor, with short-distance expansion as an input. Our basis is the Gell-Mann--Low Renormalization Group, and optimism about sufficient analyticity of correlation functions. In the test case of Tonks-Girardeau gas, a rare model where both short and long-distance expansions are known, already the first non-zero subleading term of the short-distance expansion gives the long-distance prefactor to within 15%. ..While Wilson's Renormalization Group makes high energy cutoffs irrelevant, we actually determine them for Haldane model. A byproduct of our method is an interpolation between short and long-distance behaviors, which we use to treat interaction-induced decoherence in atom interferometers.

  2. Formulating policies for the welfare of animals during long distance transportation.

    Science.gov (United States)

    Gavinelli, Andrea; Ferrara, Maria; Simonin, Denis

    2008-01-01

    Long distance transportation of animals creates much public concern in the European Union (EU) and elsewhere, partly because of its visibility to the general public. The protection of animals during transport is thus a key element of EU policy for farm animal welfare. At the same time, animal transport has been vital to the structure of the food chain in Europe since the beginning of the Common Agricultural Policy. The authors describe the formulation of EU policy on long distance transportation. Initiatives are based on scientific risk assessment and considerations of international guidelines. The two main objectives of EU policy are to reduce long distance transportation as far as possible and to upgrade standards for transported animals. The extent of detail in regulations depends on the ability of the sector concerned to address issues and on continual upgrading of the awareness and knowledge of transport operators on animal welfare which is universally important for progress. The economic impact of legislative measures must be evaluated as part of the policy process, noting that proper animal welfare standards can generate direct and indirect economic advantages. Awareness of these welfare advantages in all sectors is essential for raising the quality of enforcement. Finally, policy goals should be monitored to verify the extent of their fulfilment. Efforts from competent authorities and transport companies in Europe are improving the situation. However, a strong legislative framework is likely to remain the best option for the coming years to ensure that the welfare of transported animals is more than just a minimum.

  3. Population genetic structure and long-distance dispersal of a recently expanding migratory bird.

    Science.gov (United States)

    Ramos, Raül; Song, Gang; Navarro, Joan; Zhang, Ruiying; Symes, Craig T; Forero, Manuela G; Lei, Fumin

    2016-06-01

    Long-distance dispersal events and their derivable increases of genetic diversity have been highlighted as important ecological and evolutionary determinants that improve performances of range-expanding species. In the context of global environmental change, specific dispersal strategies have to be understood and foreseen if we like to prevent general biodiversity impoverishment or the spread of allochthonous diseases. We explored the genetic structure and potential population mixing on the recently range-expanding European bee-eater Merops apiaster. In addition, the species is suspected of harbouring and disseminating the most relevant disease for bees and apiculture, Nosema microsporidia. In agreement with complementary ringing recovery data and morphometric measurements, genetic results on two mitochondrial genes and 12 microsatellites showed a reasonably well-structured population partitioning along its breeding distribution. Microsatellite results indicated that not only did a few birds recently disperse long distance during their return migrations and change their natal breeding areas, but also that a group of allochthonous birds together founded a new colony. Although we did not provide evidence on the direct implication of birds in the widespread of Nosema parasites, our finding on the long-distance dispersal of bird flocks between remote breeding colonies adds concern about the role of European bee-eaters in the spread of such disease at a large, inter-continental scale.

  4. Long-distance entanglement in many-body atomic and optical systems

    CERN Document Server

    Giampaolo, Salvatore M

    2009-01-01

    We discuss the phenomenon of long-distance entanglement in the ground state of quantum spin models, its use in high-fidelity and robust quantum communication, and its realization in many-body systems of ultracold atoms in optical lattices and in arrays of coupled optical cavities. We investigate different patterns of site-dependent interaction couplings, singling out two general settings: Patterns that allow for perfect long-distance entanglement (LDE) in the ground state of the system, namely such that the end-to-end entanglement remains finite in the thermodynamic limit, and patterns of quasi long-distance entanglement (QLDE) in the ground state of the system, namely, such such that the end-to-end entanglement vanishes with a very slow power-law decay as the length of the spin chain is increased. We discuss physical realizations of these models in ensembles of ultracold bosonic atoms loaded in optical lattices. We show how, using either suitably engineered super-lattice structures or exploiting the presence...

  5. A circulation mud system used in long-distance ore pipeline transportation

    Science.gov (United States)

    Li, Youling; Wang, Hua

    2011-10-01

    The long-distance ore pipeline transportation is a new and high-tech industry, which is non-polluting, zero emissions, and in line with the strategy needs of national low-carbon economy and energy demand reduction. The long-distance ore transport needs multi-station pumping station transportation, however, the low concentration slurry that does not match the technological requirements, such as slurry head and so on. This paper designs a circulation mud system used in long-distance pipeline transportation, which solves the following issues: (1) the technical pool can't storage water during the period of cleaning mine, so can't meet the needs of non-suspension production; (2) slurry spot cool dry easy to bring serious environmental pollution; (3) the refined iron dug out from the process pool need transport to iron and steel industry, trucking transportation needs a huge costs. Experience has shown that the system effectively improve the production efficiency and propagate.

  6. Moving Large Data Sets Over High-Performance Long Distance Networks

    Energy Technology Data Exchange (ETDEWEB)

    Hodson, Stephen W [ORNL; Poole, Stephen W [ORNL; Ruwart, Thomas [ORNL; Settlemyer, Bradley W [ORNL

    2011-04-01

    In this project we look at the performance characteristics of three tools used to move large data sets over dedicated long distance networking infrastructure. Although performance studies of wide area networks have been a frequent topic of interest, performance analyses have tended to focus on network latency characteristics and peak throughput using network traffic generators. In this study we instead perform an end-to-end long distance networking analysis that includes reading large data sets from a source file system and committing large data sets to a destination file system. An evaluation of end-to-end data movement is also an evaluation of the system configurations employed and the tools used to move the data. For this paper, we have built several storage platforms and connected them with a high performance long distance network configuration. We use these systems to analyze the capabilities of three data movement tools: BBcp, GridFTP, and XDD. Our studies demonstrate that existing data movement tools do not provide efficient performance levels or exercise the storage devices in their highest performance modes. We describe the device information required to achieve high levels of I/O performance and discuss how this data is applicable in use cases beyond data movement performance.

  7. Anthropometric and functional characteristics of Colombian elite long-distance runners

    Directory of Open Access Journals (Sweden)

    Ramírez-Vélez, Robinson

    2015-07-01

    Full Text Available Objective: To evaluate the anthropometric and physical performance characteristics of elite long-distance runners. Methods: A cross-sectional study in 19 male competitive long-distance runners of national level (age 28.2 ± 6.9 years. A total of 24 anthropometric variables were measured according to the International Society for the Advancement of Kinanthropometry (ISAK statements. The Heath-Carter method and the formula proposed by Siri, Matiegka, Jackson and Pollock were used to calculate the somatotype and the body composition, respectively. Ergospirometry VO (2 max, Vertical Jump Test and the Wingate Test were used as functional indicators. Results: Regarding body composition, we found fat mass percentage 13.3 ± 3.2; muscle mass 47.3 ± 2.5%, and body adiposity index 24.1 ± 3.3. Somatotype profile was the mesomorphic-balanced (3.6-4.0-2.1. Mean values of functional tests with their standard deviations were: VO(2 máx (mL•kg-1•min-1 42.6 ± 8.1; anaerobic power 106.0 ± 31.8 kg•s-1, and anaerobic capacity 6501.0 ± 1831.6 K/jul. Conclusion: These results may provide a profile of long-distance runners that can be used as training targets for developing athletes. The results may also provide information for training and tactical emphasis.

  8. Long-distance dispersal in migratory pied flycatchers Ficedula hypoleuca is relatively common between the UK and the Netherlands

    NARCIS (Netherlands)

    Both, C.; Robinson, R.A.; Van der Jeugd, H.P.

    2012-01-01

    Long-distance dispersal can potentially have important consequences for evolutionary change, but is difficult to quantify. We present quantitative estimates of natal dispersal between the UK and the Netherlands in a long-distance migratory bird, the pied flycatcher. Due to over 90 000 individual rin

  9. The use of bead beating to prepare suspensions of nuclei for flow cytometry from fresh leaves, herbarium leaves, petals and pollen.

    Science.gov (United States)

    Roberts, Andy V

    2007-12-01

    "Bead beating" is commonly used to release DNA from cells for genomic studies but it was used here to prepare suspensions of plant nuclei for measurement of DNA amounts by flow cytometry. Plant material was placed in 2-ml screw-capped tubes containing beads of zirconia/silica (2.5 mm diameter) or glass (2.5 or 1.0 mm diameter) and 1 ml of lysis buffer. The tubes were mechanically shaken with an FP120 FastPrep Cell Disrupter to release intact nuclei from plant tissue by the impact of the beads. The nuclei were then stained with propidium iodide (PI) and analyzed by flow cytometry. The method was tested using fresh leaves, fresh petals and herbarium leaves of Rosa canina, leaves and pollen of R. rugosa, and fresh leaves of Petroselinum crispum, Nicotiana tabacum, and Allium cepa. Batches of 12 samples of fresh leaves were prepared, simultaneously, in 45 s by bead beating in the Cell Disrupter. In flow cytometry histograms, nuclei of fresh leaves gave G(1)/G(0) peaks with CVs of less than 3.0% and nuclei from fresh petals and herbarium leaves of R. canina, and pollen of the generative nuclei of R. rugosa gave peaks with coefficients of variation (CVs) of less than 4.0%. DNA amounts estimated from 24-month-old herbarium leaves, using P. crispum as an internal standard, were less than those of fresh leaves by a small but significant amount. Suspensions of nuclei can be prepared rapidly and conveniently from a diversity of tissues by bead beating. Exposure of laboratory workers to harmful substances in the lysis buffer is minimized.

  10. Diversity and conservation in maize pollen: Phenotypes and transcripts

    Science.gov (United States)

    In addition to its crucial role in seed production, pollen serves as a vector for gene flow between plant populations. Recently, pollen was identified as a mechanism for introduction of transgenes into non-transgenic populations. To investigate the genetic basis for pollen fitn...

  11. Diversity and conservation in maize pollen: Phenotypes and transcripts

    Science.gov (United States)

    In addition to its crucial role in seed production, pollen serves as a vector for gene flow between plant populations. Recently, pollen was identified as a mechanism for introduction of transgenes into non-transgenic populations. To investigate the genetic basis for pollen fitn...

  12. Pollen-mediated gene flow in a highly fragmented landscape: consequences for defining a conservation strategy of the relict Laperrine's olive.

    Science.gov (United States)

    Besnard, Guillaume; Baali-Cherif, Djamel; Bettinelli-Riccardi, Sandra; Parietti, Davis; Bouguedoura, Nadia

    2009-07-01

    In the present central Saharan conditions, the Laperrine's olive regeneration has never been observed and its populations are locally threatened. The production of plants originating from seeds was proposed as a multiplication strategy. In order to determine the impact of sexual reproduction, seeds issued from ten mothers (sampled from four locations in the Hoggar, Algeria) were genotyped using microsatellites. Compared to the initial population, a significant lost of allelic richness was revealed, indicating that our seed sampling was not representative of the local gene diversity. Paternity analyses allowed measurement of the effective pollen-mediated gene flow within patches. Preferential mating between some genotypes was revealed. A trend for a higher multipaternity on seeds collected on trees from relatively large patches was also observed. Lastly, seedlings issued from trees of small patches displayed low growth performance. The implications of our observations in the development of an efficient conservation strategy by seeds are discussed.

  13. Quantifying temporal isolation: a modelling approach assessing the effect of flowering time differences on crop-to-weed pollen flow in sunflower.

    Science.gov (United States)

    Roumet, Marie; Cayre, Adeline; Latreille, Muriel; Muller, Marie-Hélène

    2015-01-01

    Flowering time divergence can be a crucial component of reproductive isolation between sympatric populations, but few studies have quantified its actual contribution to the reduction of gene flow. In this study, we aimed at estimating pollen-mediated gene flow between cultivated sunflower and a weedy conspecific sunflower population growing in the same field and at quantifying, how it is affected by the weeds' flowering time. For that purpose, we extended an existing mating model by including a temporal distance (i.e. flowering time difference between potential parents) effect on mating probabilities. Using phenological and genotypic data gathered on the crop and on a sample of the weedy population and its offspring, we estimated an average hybridization rate of approximately 10%. This rate varied strongly from 30% on average for weeds flowering at the crop flowering peak to 0% when the crop finished flowering and was affected by the local density of weeds. Our result also suggested the occurrence of other factors limiting crop-to-weed gene flow. This level of gene flow and its dependence on flowering time might influence the evolutionary fate of weedy sunflower populations sympatric to their crop relative.

  14. Formulating policies for the welfare of animals during long distance transportation

    Directory of Open Access Journals (Sweden)

    Andrea Gavinelli

    2008-03-01

    Full Text Available Long distance transportation of animals creates much public concern in the European Union (EU and elsewhere, partly because of its visibility to the general public. The protection of animals during transport is thus a key element of EU policy for farm animal welfare. At the same time, animal transport has been vital to the structure of the food chain in Europe since the beginning of the Common Agricultural Policy. The authors describe the formulation of EU policy on long distance transportation. Initiatives are based on scientific risk assessment and considerations of international guidelines. The two main objectives of EU policy are to reduce long distance transportation as far as possible and to upgrade standards for transported animals. The extent of detail in regulations depends on the ability of the sector concerned to address issues and on continual upgrading of the awareness and knowledge of transport operators on animal welfare which is universally important for progress. The economic impact of legislative measures must be evaluated as part of the policy process, noting that proper animal welfare standards can generate direct and indirect economic advantages. Awareness of these welfare advantages in all sectors is essential for raising the quality of enforcement. Finally, policy goals should be monitored to verify the extent of their fulfilment. Efforts from competent authorities and transport companies in Europe are improving the situation. However, a strong legislative framework is likely to remain the best option for the coming years to ensure that the welfare of transported animals is more than just a minimum.

  15. Long-distance entanglement in many-body atomic and optical systems

    Energy Technology Data Exchange (ETDEWEB)

    Giampaolo, Salvatore M; Illuminati, Fabrizio [Dipartimento di Matematica e Informatica, Universita degli Studi di Salerno, Via Ponte don Melillo, I-84084 Fisciano, SA (Italy)], E-mail: illuminati@sa.infn.it

    2010-02-15

    We discuss the phenomenon of long-distance entanglement (LDE) in the ground state of quantum spin models, its use in high-fidelity and robust quantum communication, and its realization in many-body systems of ultracold atoms in optical lattices and in arrays of coupled optical cavities. We investigate XX quantum spin models on one-dimensional lattices with open ends and different patterns of site-dependent interaction couplings, singling out two general settings: patterns that allow for perfect LDE in the ground state of the system, namely such that the end-to-end entanglement remains finite in the thermodynamic limit, and patterns of quasi-long-distance entanglement (QLDE) in the ground state of the system, namely such that the end-to-end entanglement vanishes with a very slow power-law decay as the length of the spin chain is increased. We discuss physical realizations of these models in ensembles of ultracold bosonic atoms loaded in optical lattices. We show how, using either suitably engineered super-lattice structures or exploiting the presence of edge impurities in lattices with single periodicity, it is possible to realize models endowed with nonvanishing LDE or QLDE. We then study how to realize models that optimize the robustness of QLDE at finite temperature and in the presence of imperfections using suitably engineered arrays of coupled optical cavities. For both cases the numerical estimates of the end-to-end entanglement in the actual physical systems are thoroughly compared with the analytical results obtained for the spin model systems. We finally introduce LDE-based schemes of long-distance quantum teleportation in linear arrays of coupled cavities, and show that they allow for high-fidelity and high success rates even at moderately high temperatures.

  16. Massage therapy decreases pain and perceived fatigue after long-distance Ironman triathlon: a randomised trial

    Directory of Open Access Journals (Sweden)

    Guilherme S Nunes

    2016-04-01

    Full Text Available Question: Can massage therapy reduce pain and perceived fatigue in the quadriceps of athletes after a long-distance triathlon race (Ironman? Design: Randomised, controlled trial with concealed allocation, intention-to-treat analysis and blinded outcome assessors. Participants: Seventy-four triathlon athletes who completed an entire Ironman triathlon race and whose main complaint was pain in the anterior portion of the thigh. Intervention: The experimental group received massage to the quadriceps, which was aimed at recovery after competition, and the control group rested in sitting. Outcome measures: The outcomes were pain and perceived fatigue, which were reported using a visual analogue scale, and pressure pain threshold at three points over the quadriceps muscle, which was assessed using digital pressure algometry. Results: The experimental group had significantly lower scores than the control group on the visual analogue scale for pain (MD –7 mm, 95% CI –13 to –1 and for perceived fatigue (MD –15 mm, 95% CI –21 to –9. There were no significant between-group differences for the pressure pain threshold at any of the assessment points. Conclusion: Massage therapy was more effective than no intervention on the post-race recovery from pain and perceived fatigue in long-distance triathlon athletes. Trial registration: Brazilian Registry of Clinical Trials, RBR-4n2sxr. [Nunes GS, Bender PU, de Menezes FS, Yamashitafuji I, Vargas VZ, Wageck B (2016 Massage therapy decreases pain and perceived fatigue after long-distance Ironman triathlon: a randomised trial. Journal of Physiotherapy 62: 83–87

  17. Alteration of long-distance functional connectivity and network topology in patients with supratentorial gliomas

    Energy Technology Data Exchange (ETDEWEB)

    Park, Ji Eun; Kim, Ho Sung; Kim, Sang Joon; Shim, Woo Hyun [University of Ulsan College of Medicine, Department of Radiology and Research Institute of Radiology, Asan Medical Center, Songpa-Gu, Seoul (Korea, Republic of); Kim, Jeong Hoon [University of Ulsan College of Medicine, Department of Neurosurgery, Asan Medical Center, Seoul (Korea, Republic of)

    2016-03-15

    The need for information regarding functional alterations in patients with brain gliomas is increasing, but little is known about the functional consequences of focal brain tumors throughout the entire brain. Using resting-state functional MR imaging (rs-fMRI), this study assessed functional connectivity in patients with supratentorial brain gliomas with possible alterations in long-distance connectivity and network topology. Data from 36 patients with supratentorial brain gliomas and 12 healthy subjects were acquired using rs-fMRI. The functional connectivity matrix (FCM) was created using 32 pairs of cortical seeds on Talairach coordinates in each individual subject. Local and distant connectivity were calculated using z-scores in the individual patient's FCM, and the averaged FCM of patients was compared with that of healthy subjects. Weighted network analysis was performed by calculating local efficiency, global efficiency, clustering coefficient, and small-world topology, and compared between patients and healthy controls. When comparing the averaged FCM of patients with that of healthy controls, the patients showed decreased long-distance, inter-hemispheric connectivity (0.32 ± 0.16 in patients vs. 0. 42 ± 0.15 in healthy controls, p = 0.04). In network analysis, patients showed increased local efficiency (p < 0.05), but global efficiency, clustering coefficient, and small-world topology were relatively preserved compared to healthy subjects. Patients with supratentorial brain gliomas showed decreased long-distance connectivity while increased local efficiency and preserved small-world topology. The results of this small case series may provide a better understanding of the alterations of functional connectivity in patients with brain gliomas across the whole brain scale. (orig.)

  18. Long-distance regulation of Add2 pre-mRNA3′end processing

    Science.gov (United States)

    Nedeljkovic, Mirjana; Costessi, Luisa; Iaconcig, Alessandra; Porro, Fabiola; Muro, Andrés F.

    2013-01-01

    Accurate 3′end processing depends on the correct recognition of polyadenylation regulatory elements by specific protein complexes. In addition to the well-known hexanucleotide motif and downstream sequence element (DSE), less-defined auxiliary elements are usually found to modulate cleavage and polyadenylation. They are generally located in close proximity to the core polyadenylation elements but, in most of the cases, the molecular mechanisms involved are not well defined. We concentrated our studies on the regulation of the mouse β adducin (Add2) pre-mRNA cleavage and polyadenylation. It contains two proximal erythroid-specific (PAS1 and PAS2-3) and one distal brain-specific (PAS4) polyadenylation sites along the 3′UTR. Using an in vivo approach based in the transfection of minigenes containing the Add2 polyadenylation signals, we previously identified the core regulatory elements responsible for PAS4 activity. Here, we have identified two novel non-canonical cis-acting elements regulating 3′end processing at PAS4, which show long-distance activities. The first of these elements, which spans for 257 nucleotides and is located at more than 5 kb upstream the PAS4, was essential to enable processing at the Add2 PAS4. The second element, located at about 4.5 kb upstream of the PAS4, reduces PAS4 processing. Both elements display long-distance activities and, to our knowledge, long-distance upstream polyadenylation regulatory elements have not been previously described in non-viral eukaryotic transcripts. These results highlight the complexity of the regulatory mechanisms directing Add2 pre-mRNA 3′end processing, and suggests that pre-mRNA 3′ end processing of other genes may also be unexpectedly regulated by non-canonical auxiliary elements. PMID:23411391

  19. Phylogeography of the Rock Shell Thais clavigera (Mollusca): Evidence for Long-Distance Dispersal in the Northwestern Pacific.

    Science.gov (United States)

    Guo, Xiang; Zhao, Dan; Jung, Daewui; Li, Qi; Kong, Ling-Feng; Ni, Gang; Nakano, Tomoyuki; Matsukuma, Akihiko; Kim, Sanghee; Park, Chungoo; Lee, Hyuk Je; Park, Joong-Ki

    2015-01-01

    The present-day genetic structure of a species reflects both historical demography and patterns of contemporary gene flow among populations. To precisely understand how these factors shape current population structure of the northwestern (NW) Pacific marine gastropod, Thais clavigera, we determined the partial nucleotide sequences of the mitochondrial COI gene for 602 individuals sampled from 29 localities spanning almost the whole distribution of T. clavigera in the NW Pacific Ocean (~3,700 km). Results from population genetic and demographic analyses (AMOVA, ΦST-statistics, haplotype networks, Tajima's D, Fu's FS, mismatch distribution, and Bayesian skyline plots) revealed a lack of genealogical branches or geographical clusters, and a high level of genetic (haplotype) diversity within each of studied population. Nevertheless, low but significant genetic structuring was detected among some geographical populations separated by the Changjiang River, suggesting the presence of geographical barriers to larval dispersal around this region. Several lines of evidence including significant negative Tajima's D and Fu's FS statistics values, the unimodally shaped mismatch distribution, and Bayesian skyline plots suggest a population expansion at marine isotope stage 11 (MIS 11; 400 ka), the longest and warmest interglacial interval during the Pleistocene epoch. The lack of genetic structure among the great majority of the NW Pacific T. clavigera populations may be attributable to high gene flow by current-driven long-distance dispersal of prolonged planktonic larval phase of this species.

  20. Phylogeography of the Rock Shell Thais clavigera (Mollusca: Evidence for Long-Distance Dispersal in the Northwestern Pacific.

    Directory of Open Access Journals (Sweden)

    Xiang Guo

    Full Text Available The present-day genetic structure of a species reflects both historical demography and patterns of contemporary gene flow among populations. To precisely understand how these factors shape current population structure of the northwestern (NW Pacific marine gastropod, Thais clavigera, we determined the partial nucleotide sequences of the mitochondrial COI gene for 602 individuals sampled from 29 localities spanning almost the whole distribution of T. clavigera in the NW Pacific Ocean (~3,700 km. Results from population genetic and demographic analyses (AMOVA, ΦST-statistics, haplotype networks, Tajima's D, Fu's FS, mismatch distribution, and Bayesian skyline plots revealed a lack of genealogical branches or geographical clusters, and a high level of genetic (haplotype diversity within each of studied population. Nevertheless, low but significant genetic structuring was detected among some geographical populations separated by the Changjiang River, suggesting the presence of geographical barriers to larval dispersal around this region. Several lines of evidence including significant negative Tajima's D and Fu's FS statistics values, the unimodally shaped mismatch distribution, and Bayesian skyline plots suggest a population expansion at marine isotope stage 11 (MIS 11; 400 ka, the longest and warmest interglacial interval during the Pleistocene epoch. The lack of genetic structure among the great majority of the NW Pacific T. clavigera populations may be attributable to high gene flow by current-driven long-distance dispersal of prolonged planktonic larval phase of this species.

  1. Long-distance island hopping without dispersal stages: transportation across major zoogeographic barriers in a Southern Ocean isopod

    Science.gov (United States)

    Leese, Florian; Agrawal, Shobhit; Held, Christoph

    2010-06-01

    Species integrity is maintained only if recurrent allelic exchange between subpopulations occurs by means of migrating specimens. Predictions of this gene flow on the basis of observed or assumed mobility of marine species have proven to be error-prone. Using one mitochondrial gene and seven microsatellite markers, we studied the genetic structure and gene flow in Septemserolis septemcarinata, a strictly benthic species lacking pelagic larvae and the ability to swim. Suitable shallow-water habitats around three remote islands (South Georgia, Bouvet, and Marion Island) are geographically disjunct, isolated by more than 2,000 km of uninhabitable deep sea (east-west) and also separated by the Polar Front (north-south), which serves as a strong demarcation line in many marine taxa. Although we did find genetic differentiation among the three island populations, our results also revealed that a scenario with recent gene flow explains our data best. A model assuming no gene flow after initial colonization of the islands performs significantly worse. The tests also favor an asymmetric gene flow pattern (west to east ≫ east to west) thus mirroring the directionality of major oceanographic currents in the area. We conclude that rare long-distance dispersal rather than vicariance or human-mediated transport must be responsible for the observed patterns. As a mechanism, we propose passive rafting on floating substrata in the Antarctic Circumpolar Current. The results demonstrate that the effectiveness of a physical barrier is not solely a function of its physical parameters but strongly depends on how organisms interact with their environment.

  2. Long distance electron transport in marine sediments: Microbial and geochemical implications

    DEFF Research Database (Denmark)

    Risgaard-Petersen, Nils; Larsen, Steffen; Pfeffer, Christian

    redox half-reactions in distant regions of the sediment leads to formation of electrical fields, which modifies ion transport. The local proton producing and proton consuming half reactions induces pH extremes that accelerate dissolution of iron sulphides and calcium carbonates in anoxic layers...... to sulfate, and iron sulphides are the major sources for sulfide in the system. Procaryotes with the ability to perform long distance electron transmission may flourishes in marine sediments exposed to transient oxygen depletion, leaving distinct signatures of such events in the geological record....

  3. Design of New Long-Distance Intelligent Watt-Hour Meter

    Institute of Scientific and Technical Information of China (English)

    Zhao Wenlei; Xue Yanbing

    2005-01-01

    The design scheme for a new kind of long-distance intelligent watt-hour meter is presented. In the system, the control computer communicates with the bank's host computer by the X. 25 network; the built-in embeded secure access module (FSAM) can verify data by commutation with the intelligent nodes that enhance the security of the data. IC TSS721 is adopted to collect data remotely,and the CPU IC card is used to ensure the the bargaining security and reliability. In addition, the software of the system is introduced.

  4. Long distance electron transmission couples sulphur, iron, calcium and oxygen cycling in marine sediment

    DEFF Research Database (Denmark)

    Risgaard-Petersen, Nils; Nielsen, Lars Peter

    sulfide oxidation leads to electric field formation, sulfide depletion and acidification of the upper centimeters of the sediment. This promoted ion migration and dissolution of carbonates and iron sulfides. Sulfide released from iron sulfides was the major e-donor in the system. Ferrous iron released...... from iron sulfides was to a large extend deposited in the oxic zone as iron oxides and Ca2+ eventually precipitates at the surface as due to high pH caused by cathodic oxygen reduction. The result show how long distance electron transmission allows oxygen to drive the allocation of important minerals...

  5. Long-distance electronic energy transfer in light-harvesting supramolecular polymers.

    Science.gov (United States)

    Winiger, Christian B; Li, Shaoguang; Kumar, Ganesh R; Langenegger, Simon M; Häner, Robert

    2014-12-01

    The efficient collection of solar energy relies on the design and construction of well-organized light-harvesting systems. Herein we report that supramolecular phenanthrene polymers doped with pyrene are effective collectors of light energy. The linear polymers are formed through the assembly of short amphiphilic oligomers in water. Absorption of light by phenanthrene residues is followed by electronic energy transfer along the polymer over long distances (>100 nm) to the accepting pyrene molecules. The high efficiency of the energy transfer, which is documented by large fluorescence quantum yields, suggests a quantum coherent process.

  6. Long-distance remote characterization of ultrastable lasers via commercial telecommunication fiber network

    CERN Document Server

    Pape, Andre; Friebe, Jan; Riedmann, Matthias; Wübbena, Temmo; Rasel, Ernst-Maria; Predehl, Katharina; Lipphardt, Burghard; Schnatz, Harald; Grosche, Gesine

    2009-01-01

    We demonstrate a fully optical, remote characterization of independent ultrastable lasers separated by a geographical distance of more than 50 km via a 73 km long phase-stabilized fiber in a commercial telecommunication network. The phase-coherent comparison shows a fractional frequency instability between the independent ultrastable laser systems of s_y = 4E-15 for averaging times > 2 s; the remote analog transfer beat note shows a linewidth of 1 Hz. This demonstrates the potential of long-distance remote comparisons of ultrastable optical frequencies using commercial telecommunication fiber networks.

  7. Long-distance root-to-shoot transport of phytochelatins and cadmium in Arabidopsis.

    Science.gov (United States)

    Gong, Ji-Ming; Lee, David A; Schroeder, Julian I

    2003-08-19

    Phytochelatin synthases (PCS) mediate cellular heavy-metal resistance in plants, fungi, and worms. However, phytochelatins (PCs) are generally considered to function as intracellular heavy-metal detoxification mechanisms, and whether long-distance transport of PCs occurs during heavy-metal detoxification remains unknown. Here, wheat TaPCS1 cDNA expression was either targeted to Arabidopsis roots with the Arabidopsis alcohol dehydrogenase (Adh) promoter (Adh::TaPCS1/cad1-3) or ectopically expressed with the cauliflower mosaic virus 35S promoter (35S::TaPCS1/cad1-3) in the PC-deficient mutant cad1-3. Adh::TaPCS1/cad1-3 and 35S::TaPCS1/cad1-3 complemented the cadmium, mercury, and arsenic sensitivities of the cad1-3 mutant. Northern blot, RT-PCR, and Western blot analyses showed Adh promoter-driven TaPCS1 expression only in roots and thus demonstrated lack of long-distance TaPCS1 mRNA and protein transport in plants. Fluorescence HPLC analyses showed that under Cd2+ stress, no PCs were detectable in cad1-3. However, in Adh::TaPCS1/cad1-3 plants, PCs were detected in roots and in rosette leaves and stems. Inductively coupled plasma atomic emission spectrometer analyses showed that either root-specific or ectopic expression of TaPCS1 significantly enhanced long-distance Cd2+ transport into stems and rosette leaves. Unexpectedly, transgenic expression of TaPCS1 reduced Cd2+ accumulation in roots compared with cad1-3. The reduced Cd2+ accumulation in roots and enhanced root-to-shoot Cd2+ transport in transgenic plants were abrogated by l-buthionine sulfoximine. The presented findings show that (i) transgenic expression of TaPCS1 suppresses the heavy-metal sensitivity of cad1-3, (ii) PCs can be transported from roots to shoots, and (iii) transgenic expression of the TaPCS1 gene increases long-distance root-to-shoot Cd2+ transport and reduces Cd2+ accumulation in roots.

  8. Long-distance nitrate signaling displays cytokinin dependent and independent branches

    Institute of Scientific and Technical Information of China (English)

    Sandrine Ruffel; Arthur Poitout; Gabriel Krouk; Gloria M Coruzzi; Benoit Lacombe

    2016-01-01

    Summary The long-distance signaling network allowing a plant to properly develop its root system is crucial to optimize root foraging in areas where nutrients are available. Cytokinin is an essential element of the systemic signaling network leading to the enhancement of lateral root proliferation in areas where nitrate is available. Here, we explore more precisely: (i) which particular traits of lateral root growth (density and length of emerged lateral roots) are the targets of systemic signaling in a context of heterogeneous nitrate supply; and (i ) if the systemic signaling depends only on cytokinin or on a combination of several signalings.

  9. Differences in myoelectric manifestations of fatigue in sprinters and long distance runners.

    Science.gov (United States)

    Rainoldi, A; Gazzoni, M; Melchiorri, G

    2008-03-01

    The aim of this study was to determine whether the rate of change of surface EMG variables during a constant force isometric fatiguing contraction (80% MVC, 30 s of duration) of vastus medialis obliquus (VMO) and vastus lateralis (VL) muscles is able to distinguish between nine sprinters and nine long distance runners. Signals were recorded with linear arrays of eight electrodes. Muscle fiber conduction velocity (CV), mean frequency (MNF) of EMG signal power spectrum and average rectified value (ARV) of the EMG signal were calculated both from the whole signal (global approach) and from motor unit action potentials (MUAP distribution approach) extracted from the signal. Results showed significant differences only in the MUAP distribution approach. For this approach, the rates of change of conduction velocity (CV) (both absolute and normalized with respect to the initial value) were found to be always greater in the sprinter (VMO: -0.012 +/- 0.011 m s(-2) and -0.25 +/- 0.21%/s; VL: -0.014 +/- 0.009 m s(-2) and -0.27 +/- 0.17%/s) than in the long distance runner group (VMO: -0.004 +/- 0.006 m s(-2) and -0.08 +/- 0.14%/s; VL: 0.003 +/- 0.012 m s(-2) and 0.08 +/- 0.26%/s) (VL: p = 0.016, VMO: p = 0.034). No differences were observed in the CV initial values and in rates of change of MNF, while MNF initial values recorded from the VMO were found to be greater (119.6 +/- 25.1 Hz) in the sprinter group than in the long distance runner group (99.2 +/- 12.1 Hz, p = 0.016). A correlation was found between initial values and rates of change of CV in the VMO (r = 0.61, p sprinters and long distance runners and the identification of a set of candidated variables for the assessment of muscle adaptation during training and/or rehabilitation programs represent the main results of the study.

  10. Research on Methods of Nutrition after Middle and Long Distance Runners Training of Teenagers

    Directory of Open Access Journals (Sweden)

    Yang Yu

    2015-02-01

    Full Text Available This study uses the method of literature research, interview, investigation, mathematical statistics and so on, combined with the actual situation in the teaching and training, analyzing the two main factors to affect the adolescent fatigue of muscles and nervous system after the middle distance race training, exploring the methods and measures of the recovery. Through the data access, our country to the adult middle-long-distance athletes training research has a lot of, but for teenage training, especially (youth physical training methods, characteristics and should pay attention to problem research is less.

  11. Less pollen-mediated gene flow for more signatures of glacial lineages: congruent evidence from balsam fir cpDNA and mtDNA for multiple refugia in eastern and central North America.

    Directory of Open Access Journals (Sweden)

    Benjamin Cinget

    Full Text Available The phylogeographic structure and postglacial history of balsam fir (Abies balsamea, a transcontinental North American boreal conifer, was inferred using mitochondrial DNA (mtDNA and chloroplast DNA (cpDNA markers. Genetic structure among 107 populations (mtDNA data and 75 populations (cpDNA data was analyzed using Bayesian and genetic distance approaches. Population differentiation was high for mtDNA (dispersed by seeds only, but also for cpDNA (dispersed by seeds and pollen, indicating that pollen gene flow is more restricted in balsam fir than in other boreal conifers. Low cpDNA gene flow in balsam fir may relate to low pollen production due to the inherent biology of the species and populations being decimated by recurrent spruce budworm epidemics, and/or to low dispersal of pollen grains due to their peculiar structural properties. Accordingly, a phylogeographic structure was detected using both mtDNA and cpDNA markers and population structure analyses supported the existence of at least five genetically distinct glacial lineages in central and eastern North America. Four of these would originate from glacial refugia located south of the Laurentide ice sheet, while the last one would have persisted in the northern Labrador region. As expected due to reduced pollen-mediated gene flow, congruence between the geographic distribution of mtDNA and cpDNA lineages was higher than in other North American conifers. However, concordance was not complete, reflecting that restricted but nonetheless detectable cpDNA gene flow among glacial lineages occurred during the Holocene. As a result, new cpDNA and mtDNA genome combinations indicative of cytoplasmic genome capture were observed.

  12. Less pollen-mediated gene flow for more signatures of glacial lineages: congruent evidence from balsam fir cpDNA and mtDNA for multiple refugia in eastern and central North America.

    Science.gov (United States)

    Cinget, Benjamin; Gérardi, Sébastien; Beaulieu, Jean; Bousquet, Jean

    2015-01-01

    The phylogeographic structure and postglacial history of balsam fir (Abies balsamea), a transcontinental North American boreal conifer, was inferred using mitochondrial DNA (mtDNA) and chloroplast DNA (cpDNA) markers. Genetic structure among 107 populations (mtDNA data) and 75 populations (cpDNA data) was analyzed using Bayesian and genetic distance approaches. Population differentiation was high for mtDNA (dispersed by seeds only), but also for cpDNA (dispersed by seeds and pollen), indicating that pollen gene flow is more restricted in balsam fir than in other boreal conifers. Low cpDNA gene flow in balsam fir may relate to low pollen production due to the inherent biology of the species and populations being decimated by recurrent spruce budworm epidemics, and/or to low dispersal of pollen grains due to their peculiar structural properties. Accordingly, a phylogeographic structure was detected using both mtDNA and cpDNA markers and population structure analyses supported the existence of at least five genetically distinct glacial lineages in central and eastern North America. Four of these would originate from glacial refugia located south of the Laurentide ice sheet, while the last one would have persisted in the northern Labrador region. As expected due to reduced pollen-mediated gene flow, congruence between the geographic distribution of mtDNA and cpDNA lineages was higher than in other North American conifers. However, concordance was not complete, reflecting that restricted but nonetheless detectable cpDNA gene flow among glacial lineages occurred during the Holocene. As a result, new cpDNA and mtDNA genome combinations indicative of cytoplasmic genome capture were observed.

  13. High-performance HVDC transmission over long distances; Hochleistungsuebertragung ueber grosse Entfernungen mit hochgespanntem Gleichstrom

    Energy Technology Data Exchange (ETDEWEB)

    Radtke, U. [PreussenElektra AG, Hannover (Germany)

    1998-12-31

    High-voltage DC transmission is a world-wide established technology for low-cost transmission of large amounts of electricity over long distances. Thanks to HVDC transmission, large amounts of electricity can now for the first time also be transmitted over long distances via ocean cable, something that cannot be done with AC power cables. HVDC transmission is independent of grid frequencies and can link grids of different frequency and different quality of frequency. Interconnected grids coupled via DC circuits can exploit additional technical and economic advantages such as mutual supply of power reserves, balancing of peak load, and modulation of active and reactive power. (orig.) [Deutsch] Die Hochspannungs-Gleichstromuebertragung (HGUe) ist eine weltweit etablierte Technik zur kostenguenstigen Uebertragung grosser elektrischer Leistungen ueber grosse Entfernungen. Sie schafft erstmals die Moeglichkeit, auch mittels Seekabel grosse Leistungen ueber Entfernungen zu uebertragen, die mit der Drehstromtechnik nicht moeglich sind. HGUeist unabhaengig von den Netzfrequenzen und kann Netze unterschiedlicher Frequenz und Frequenzguete miteinander verbinden. Ueber Gleichstromkreise gekuppelte Verbundnetze koennen zusaetzliche technische und wirtschaftliche Vorteile wie gegenseitige Bereitstellung von Kraftwerksreserven, Spitzenlastausgleich sowie Wirk- und Blindleistungsmodulation nutzt. (orig.)

  14. 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.

  15. Comprehensive long distance and real-time pipeline monitoring system based on fiber optic sensing

    Energy Technology Data Exchange (ETDEWEB)

    Nikles, Marc; Ravet, Fabien; Briffod, Fabien [Omnisens S.A., Morges (Switzerland)

    2009-07-01

    An increasing number of pipelines are constructed in remote regions affected by harsh environmental conditions. These pipeline routes often cross mountain areas which are characterized by unstable grounds and where soil texture changes between winter and summer increase the probability of hazards. Due to the long distances to be monitored and the linear nature of pipelines, distributed fiber optic sensing techniques offer significant advantages and the capability to detect and localize pipeline disturbance with great precision. Furthermore pipeline owner/operators lay fiber optic cable parallel to transmission pipelines for telecommunication purposes and at minimum additional cost monitoring capabilities can be added to the communication system. The Brillouin-based Omnisens DITEST monitoring system has been used in several long distance pipeline projects. The technique is capable of measuring strain and temperature over 100's kilometers with meter spatial resolution. Dedicated fiber optic cables have been developed for continuous strain and temperature monitoring and their deployment along the pipeline has enabled permanent and continuous pipeline ground movement, intrusion and leak detection. This paper presents a description of the fiber optic Brillouin-based DITEST sensing technique, its measurement performance and limits, while addressing future perspectives for pipeline monitoring. (author)

  16. Effect of long-distance transportation on serum metabolic profiles of steer calves.

    Science.gov (United States)

    Takemoto, Satoshi; Tomonaga, Shozo; Funaba, Masayuki; Matsui, Tohru

    2017-07-19

    Long-distance transportation is sometimes inevitable in the beef industry because of the geographic separation of major breeding and fattening areas. Long-distance transportation negatively impacts production and health of cattle, which may, at least partly, result from the disturbance of metabolism during and after transportation. However, alteration of metabolism remains elusive in transported cattle. We investigated the effects of transportation on the metabolomic profiles of Holstein steer calves. Non-targeted analysis of serum concentrations of low molecular weight metabolites was performed by gas chromatography mass spectrometry. Transportation affected 38 metabolites in the serum. A pathway analysis suggested that 26, 10, and 10 pathways were affected immediately after transportation, and 3 and 7 days after transportation, respectively. Some pathways were disturbed only immediately after transportation, likely because of feed and water withdrawal during transit. Nicotinate and nicotinamide metabolism, and citric acid cycle were affected for 3 days after transportation, whereas propionate metabolism, phenylalanine and tyrosine metabolism were affected throughout the experiment. Four pathways were not affected immediately after transportation, but were altered thereafter. These results suggested that many metabolic pathways had marked perturbations during transportation. Metabolites such as citric acid, propionate, tyrosine and niacin can be candidate supplements for mitigating transportation-induced adverse effects. © 2017 Japanese Society of Animal Science.

  17. Plantar Pressures During Long Distance Running: An Investigation of 10 Marathon Runners

    Directory of Open Access Journals (Sweden)

    Erik Hohmann, Peter Reaburn, Kevin Tetsworth, Andreas Imhoff

    2016-06-01

    Full Text Available The objective of this study was to record plantar pressures using an in-shoe measuring system before, during, and after a marathon run in ten experienced long-distance runners with a mean age of 37.7 ± 11.5 years. Peak and mean plantar pressures were recorded before, after, and every three km during a marathon race. There were no significant changes over time in peak and mean plantar pressures for either the dominant or non-dominant foot. There were significant between foot peak and mean plantar pressure differences for the total foot (p = 0.0001, forefoot (p = 0.0001, midfoot (p = 0.02 resp. p = 0.006, hindfoot (p = 0.0001, first ray (p = 0.01 resp. p = 0.0001 and MTP (p = 0.05 resp. p = 0.0001. Long-distance runners do not demonstrate significant changes in mean or peak plantar foot pressures over the distance of a marathon race. However, athletes consistently favoured their dominant extremity, applying significantly higher plantar pressures through their dominant foot over the entire marathon distance.

  18. Repeatability of individual migration routes, wintering sites, and timing in a long-distance migrant bird.

    Science.gov (United States)

    van Wijk, Rien E; Bauer, Silke; Schaub, Michael

    2016-12-01

    Migratory birds are often faithful to wintering (nonbreeding) sites, and also migration timing is usually remarkably consistent, that is, highly repeatable. Spatiotemporal repeatability can be of advantage for multiple reasons, including familiarity with local resources and predators as well as avoiding the costs of finding a new place, for example, nesting grounds. However, when the environment is variable in space and time, variable site selection and timing might be more rewarding. To date, studies on spatial and temporal repeatability in short-lived long-distance migrants are scarce, most notably of first-time and subsequent migrations. Here, we investigated repeatability in autumn migration directions, wintering sites, and annual migration timing in Hoopoes (Upupa epops), a long-distance migrant, using repeated tracks of adult and first-time migrants. Even though autumn migration directions were mostly the same, individual wintering sites often changed from year to year with distances between wintering sites exceeding 1,000 km. The timing of migration was repeatable within an individual during autumn, but not during spring migration. We suggest that Hoopoes respond to variable environmental conditions such as north-south shifts in rainfall during winter and differing onset of the food availability during spring migration.

  19. US long distance fiber optic networks: Technology, evolution and advanced concepts. Volume 1: Executive summary

    Science.gov (United States)

    1986-01-01

    Over the past two decades, fiber optics has emerged as a highly practical and cost-efficient communications technology. Its competitiveness vis-a-vis other transmission media, especially satellite, has become a critical question. This report studies the likely evolution and application of fiber optic networks in the United States to the end of the century. The outlook for the technology of fiber systems is assessed and forecast, scenarios of the evolution of fiber optic network development are constructed, and costs to provide service are determined and examined parametrically as a function of network size and traffic carried. Volume 1 consists of the Executive Summary. Volume 2 focuses on fiber optic technology and long distance fiber optic networks. Volume 3 develops a traffic and financial model of a nationwide long distance transmission network. Among the study's most important conclusions are: revenue requirements per circuit for LATA-to-LATA fiber optic links are less than one cent per call minute; multiplex equipment, which is likely to be required in any competing system, is the largest contributor to circuit costs; the potential capacity of fiber optic cable is very large and as yet undefined; and fiber optic transmission combined with other network optimization schemes can lead to even lower costs than those identified in this study.

  20. Recent Advances in Long-distance FBG Sensor Systems at UESTC

    Institute of Scientific and Technical Information of China (English)

    RAO Yun-Jiang; RAN Zeng-Ling

    2006-01-01

    Recent progress in long-distance in-Fiber Bragg Grating (FBG) sensor systems at University of Electronic Science & Technology of China (UESTC) is reviewed in this paper. Two novel approaches with a 50km transmission distance are proposed and demonstrated. The first one is based on the combination of bidirectional Raman amplification and a dual Erbium-Doped Fiber (EDF) configuration. A good Signal-to-Noise Ratio (SNR) of ~16dB is achieved with only a pump power of ~280 mW, which is ~10 dB higher than that without amplification. The second is based on a novel tunable fiber ring laser configuration with hybrid Raman/EDFA configuration. Experimental results show that an excellent optical SNR of ~60 dB has been achieved for a 50 km transmission distance with a low Raman pump power of ~170 mW and a low EDFA pump power of ~40 mW at wavelength of 980 nm. It is anticipated that these long-distance FBG sensing systems could find important applications in health monitoring of large infra-structures, such as oil or gas pipelines, ultra-long bridges and tunnels, river banks, and so on.

  1. Capability of long distance 100  GHz FMCW using a single GDD lamp sensor.

    Science.gov (United States)

    Levanon, Assaf; Rozban, Daniel; Aharon Akram, Avihai; Kopeika, Natan S; Yitzhaky, Yitzhak; Abramovich, Amir

    2014-12-20

    Millimeter wave (MMW)-based imaging systems are required for applications in medicine, homeland security, concealed weapon detection, and space technology. The lack of inexpensive room temperature imaging sensors makes it difficult to provide a suitable MMW system for many of the above applications. A 3D MMW imaging system based on chirp radar was studied previously using a scanning imaging system of a single detector. The radar system requires that the millimeter wave detector will be able to operate as a heterodyne detector. Since the source of radiation is a frequency modulated continuous wave (FMCW), the detected signal as a result of heterodyne detection gives the object's depth information according to value of difference frequency, in addition to the reflectance of the 2D image. New experiments show the capability of long distance FMCW detection by using a large scale Cassegrain projection system, described first (to our knowledge) in this paper. The system presents the capability to employ a long distance of at least 20 m with a low-cost plasma-based glow discharge detector (GDD) focal plane array (FPA). Each point on the object corresponds to a point in the image and includes the distance information. This will enable relatively inexpensive 3D MMW imaging.

  2. Firm insoles effectively reduce hemolysis in runners during long distance running - a comparative study.

    Science.gov (United States)

    Janakiraman, Kamal; Shenoy, Shweta; Sandhu, Jaspal Singh

    2011-06-09

    Shock absorbing insoles are effective in reducing the magnitude and rate of loading of peak impact forces generated at foot strike during running, whereas the foot impact force during running has been considered to be an important cause of intravascular hemolysis in long distance runners. Objective of this study was to evaluate the intravascular hemolysis during running and compare the effect of two different types of insoles (Soft and Firm) on hemolysis. Twenty male long and middle distance runners volunteered to participate in this study. We selected two insoles (Soft and Firm) according to their hardness level (SHORE 'A' scale). Participants were randomly assigned to the soft insole (group 1) and firm insole (group 2) group with ten athletes in each group. Each athlete completed one hour of running at the calculated target heart rate (60-70%). Venous blood samples were collected before and immediately after running. We measured unconjucated bilirubin (mg/dl), lactate dehydrogenase (μ/ml), hemoglobin (g/l) and serum ferritin (ng/ml) as indicators of hemolysis. Our study revealed a significant increase in the mean values of unconjucated bilirubin (P running with soft insoles indicating the occurrence of hemolysis in this group of athletes. Graphical analysis revealed an inverse relationship between hardness of insoles and hemolysis for the observed values. Our results indicate that intravascular hemolysis occurs in athletes during long distance running and we conclude that addition of firm insoles effectively reduces the amount of hemolysis in runners compared to soft insoles.

  3. Firm insoles effectively reduce hemolysis in runners during long distance running - a comparative study

    Directory of Open Access Journals (Sweden)

    Janakiraman Kamal

    2011-06-01

    Full Text Available Abstract Background Shock absorbing insoles are effective in reducing the magnitude and rate of loading of peak impact forces generated at foot strike during running, whereas the foot impact force during running has been considered to be an important cause of intravascular hemolysis in long distance runners. Objective of this study was to evaluate the intravascular hemolysis during running and compare the effect of two different types of insoles (Soft and Firm on hemolysis. Methods Twenty male long and middle distance runners volunteered to participate in this study. We selected two insoles (Soft and Firm according to their hardness level (SHORE 'A' scale. Participants were randomly assigned to the soft insole (group 1 and firm insole (group 2 group with ten athletes in each group. Each athlete completed one hour of running at the calculated target heart rate (60-70%. Venous blood samples were collected before and immediately after running. We measured unconjucated bilirubin (mg/dl, lactate dehydrogenase (μ/ml, hemoglobin (g/l and serum ferritin (ng/ml as indicators of hemolysis. Results Our study revealed a significant increase in the mean values of unconjucated bilirubin (P Conclusion Our results indicate that intravascular hemolysis occurs in athletes during long distance running and we conclude that addition of firm insoles effectively reduces the amount of hemolysis in runners compared to soft insoles.

  4. Plantar Pressures During Long Distance Running: An Investigation of 10 Marathon Runners

    Science.gov (United States)

    Hohmann, Erik; Reaburn, Peter; Tetsworth, Kevin; Imhoff, Andreas

    2016-01-01

    The objective of this study was to record plantar pressures using an in-shoe measuring system before, during, and after a marathon run in ten experienced long-distance runners with a mean age of 37.7 ± 11.5 years. Peak and mean plantar pressures were recorded before, after, and every three km during a marathon race. There were no significant changes over time in peak and mean plantar pressures for either the dominant or non-dominant foot. There were significant between foot peak and mean plantar pressure differences for the total foot (p = 0.0001), forefoot (p = 0.0001), midfoot (p = 0.02 resp. p = 0.006), hindfoot (p = 0.0001), first ray (p = 0.01 resp. p = 0.0001) and MTP (p = 0.05 resp. p = 0.0001). Long-distance runners do not demonstrate significant changes in mean or peak plantar foot pressures over the distance of a marathon race. However, athletes consistently favoured their dominant extremity, applying significantly higher plantar pressures through their dominant foot over the entire marathon distance. Key points Fatigue does not increase foot pressures Every runner has a dominant foot where pressures are higher and that he/she favours Foot pressures do not increase over the distance of a marathon run PMID:27274662

  5. Confession-building, long-distance networks, and the organization of Jesuit science.

    Science.gov (United States)

    Harris, S J

    1996-01-01

    The ability of the Society of Jesus to engage in a broad and enduring tradition of scientific activity is here addressed in terms of its programmatic commitment to the consolidation and extension of the Catholic confession (i.e., to a multipronged program of confession-building) and its mastery of the administrative apparatus necessary to operate long-distance networks. The Society's early move into two major apostolates, one in education and the other in the overseas missions, brought Jesuits into regular contact with the educated elites of Europe and at the same time placed the society's missionaries in remote parts of the natural world. The modes of organization of travel and communication required by the Society's long-distance networks (i.e., the training and deployment of reliable agents willing to work under direction in remote locations and capable of providing trustworthy reports and observations to their superiors through regular exchange of correspondence) not only facilitated scientific communication and collaboration within the order, it also provided Jesuits with the resources they needed to engage successfully in 'ministries among the learned'. Evidence of a sustained attempt by Jesuit authors to assume the role of Kulturträger is found in the several genres of scientific publications that dominate the society's scientific corpus. Thus the society's early recognition of the "apostolic value" of scientific publications in recruiting friends and allies among Europe's intellectual elites, I argue, allowed a robust interest in natural knowledge to emerge as a legitimate part of the Jesuit vocation.

  6. Ecological specialization to fluctuating resources prevents long-distance migratory raptors from becoming sedentary on islands.

    Directory of Open Access Journals (Sweden)

    Laura Gangoso

    Full Text Available BACKGROUND: The adaptive transition between behavioral strategies, such as the shift from migratoriness to sedentariness, remains an outstanding question in evolutionary ecology. Density-dependent variation in the age of first breeding has been proposed as a feasible mechanism through which long-lived migratory birds with deferred sexual maturity should become sedentary to persist on islands. Although this pattern seems to hold for most raptors and herons, a few exceptions have been identified. One of these exceptions is the Eleonora's falcon, a long-distance migratory bird, which shows one of the most peculiar adaptations in the timing of reproduction and food requirements among raptors. METHODOLOGY/PRINCIPAL FINDINGS: Here, we compiled data concerning demography, banding recoveries and satellite tracking of Eleonora's falcons to discuss likely explanations for the exceptional behavior of this insular long-distance migratory species. CONCLUSIONS/SIGNIFICANCE: New data reveal that Eleonora's falcons do return to the natal colonies in their first year and young birds are able to breed. However, in contrast to previous hypothesis, the highly specialized strategy of this and other ecologically similar species, as well as the virtual lack of food during winter at breeding areas prevent them from becoming sedentary on islands. Although the ultimate mechanisms underlying the process of sedentarization remain poorly understood, the evidence provided reveal the existence of important trade-offs associated with ecological specialization that may become particularly relevant in the present context of global change.

  7. Factors associated with falling asleep at the wheel among long-distance truck drivers.

    Science.gov (United States)

    McCartt, A T; Rohrbaugh, J W; Hammer, M C; Fuller, S Z

    2000-07-01

    Data on the prevalence and hypothesized predictors of falling asleep while driving were gathered through face-to-face interviews with 593 long-distance truck drivers randomly selected at public and private rest areas and routine roadside truck safety inspections. Hypothesized predictor variables related to drivers' typical work and rest patterns, extent of daytime and night-time drowsiness, symptoms of sleep disorder, measures of driving exposure, and demographic characteristics. A sizeable proportion of long-distance truck drivers reported falling asleep at the wheel of the truck: 47.1% of the survey respondents had ever fallen asleep at the wheel of a truck, and 25.4% had fallen asleep at the wheel in the past year. Factor analysis reduced the large set of predictors to six underlying, independent factors: greater daytime sleepiness; more arduous schedules, with more hours of work and fewer hours off-duty; older, more experienced drivers; shorter, poorer sleep on road; symptoms of sleep disorder; and greater tendency to night-time drowsy driving. Based on multivariate logistic regression, all six factors were predictive of self-reported falling asleep at the wheel. Falling asleep was also associated with not having been alerted by driving over shoulder rumble strips. The results suggest that countermeasures that limit drivers' work hours and enable drivers to get adequate rest and that identify drivers with sleep disorders are appropriate methods to reduce sleepiness-related driving by truck drivers.

  8. Long-distance aerial dispersal modelling of Culicoides biting midges: case studies of incursions into Australia.

    Science.gov (United States)

    Eagles, Debbie; Melville, Lorna; Weir, Richard; Davis, Steven; Bellis, Glenn; Zalucki, Myron P; Walker, Peter J; Durr, Peter A

    2014-06-19

    Previous studies investigating long-distance, wind-borne dispersal of Culicoides have utilised outbreaks of clinical disease (passive surveillance) to assess the relationship between incursion and dispersal event. In this study, species of exotic Culicoides and isolates of novel bluetongue viruses, collected as part of an active arbovirus surveillance program, were used for the first time to assess dispersal into an endemic region. A plausible dispersal event was determined for five of the six cases examined. These include exotic Culicoides specimens for which a possible dispersal event was identified within the range of two days--three weeks prior to their collection and novel bluetongue viruses for which a dispersal event was identified between one week and two months prior to their detection in cattle. The source location varied, but ranged from Lombok, in eastern Indonesia, to Timor-Leste and southern Papua New Guinea. Where bluetongue virus is endemic, the concurrent use of an atmospheric dispersal model alongside existing arbovirus and Culicoides surveillance may help guide the strategic use of limited surveillance resources as well as contribute to continued model validation and refinement. Further, the value of active surveillance systems in evaluating models for long-distance dispersal is highlighted, particularly in endemic regions where knowledge of background virus and vector status is beneficial.

  9. Characterization of the maize pollen transcriptome: Validation of microarray results using quantitative real-time PCR

    Science.gov (United States)

    Pollen is the primary means of gene flow between plants and plant populations and plays a critical role in seed production. Pollen fitness can be defined as the ability of a particular pollen grain to outcompete other pollen present on the stigma and complete fertilization, thus ...

  10. Tracing back seed and pollen flow within the crop-wild Beta vulgaris complex: genetic distinctiveness vs. hot spots of hybridization over a regional scale.

    Science.gov (United States)

    Viard, Frédérique; Arnaud, Jean-François; Delescluse, Maxime; Cuguen, Joël

    2004-06-01

    Hybrids between transgenic crops and wild relatives have been documented successfully in a wide range of cultivated species, having implications on conservation and biosafety management. Nonetheless, the magnitude and frequency of hybridization in the wild is still an open question, in particular when considering several populations at the landscape level. The Beta vulgaris complex provides an excellent biological model to tackle this issue. Weed beets contaminating sugar beet fields are expected to act as a relay between wild populations and crops and from crops-to-crops. In one major European sugar beet production area, nine wild populations and 12 weed populations were genetically characterized using cytoplasmic markers specific to the cultivated lines and nuclear microsatellite loci. A tremendous overall genetic differentiation between neighbouring wild and weed populations was depicted. However, genetic admixture analyses at the individual level revealed clear evidence for gene flow between wild and weed populations. In particular, one wild population displayed a high magnitude of nuclear genetic admixture, reinforced by direct seed flow as evidenced by cytoplasmic markers. Altogether, weed beets were shown to act as relay for gene flow between crops to wild populations and crops to crops by pollen and seeds at a landscape level.

  11. An improved pollen collection and cryopreservation method for highly recalcitrant tropical fruit species of mango (Mangifera indica L.) and litchi (Litchi chinensis Sonn.).

    Science.gov (United States)

    Chaudhury, Rekha; Malik, S K; Rajan, S

    2010-01-01

    An improved method for pollen collection from freshly dehiscing anthers of mango (Mangifera indica L.) and litchi (Litchi chinensis Sonn.) using the organic solvent cyclohexane has been devised. Using this method pollen quantity sufficient for large scale pollinations could be collected and stored for future use. Transport of pollen in viable conditions over long distances, from site of collection (field genebank) to cryolab was successfully devised for both these fruit species. Cryopreservation was successfully applied to achieve long-term pollen storage over periods of up to four years. Pollen viability was tested using in vitro germination, the fluorochromatic reaction (FCR) method and by fruit set following field pollination. On retesting, four year cryostored pollen of different mango and litchi varieties showed high percentage viability as good as fresh control pollens. Pollens of more than 180 cultivars of mango and 19 cultivars of litchi have been stored in the cryogenebank using the technology developed, thus facilitating breeding programmes over the long-term.

  12. Telephone and Cable Lines, Long Distance, Published in 2006, 1:1200 (1in=100ft) scale, Farmer.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Telephone and Cable Lines, Long Distance dataset, published at 1:1200 (1in=100ft) scale, was produced all or in part from Field Survey/GPS information as of...

  13. Danish long distance travel A study of Danish travel behaviour and the role of infrequent travel activities

    OpenAIRE

    Knudsen, Mette Aagaard; Rich, Jeppe; Nielsen, Otto Anker

    2014-01-01

    Historically there has been a lack of knowledge with respect to long distance travel. Due to the considerable contribution of long distance travel to total travelled kilometres and the related energy consumption from the transport sector and derived impacts on greenhouse emissions, this is problematic. The average travel distance has steadily increased during the latest decades together with the increasing motorisation of daily travel and international aviation. Previously most focus has been...

  14. Multilocus phylogeography (mitochondrial, autosomal and Z-chromosomal loci) and genetic consequence of long-distance male dispersal in Black-throated tits (Aegithalos concinnus).

    Science.gov (United States)

    Dai, C; Wang, W; Lei, F

    2013-05-01

    Multilocus data from the different genomes are essential to understand the phylogeographic history of species, particularly when a species has the male-biased dispersal pattern. Although Black-throated tits (Aegithalos concinnus) are socially monogamous and cooperatively breeding birds, limited observational data suggested that males may have the ability of long-distance dispersal. We have previously detected three highly supported mitochondrial populations within two subspecies of Black-throated tits (A. c. concinnus and A. c. talifuensis). Here, we used several genetic markers with different inheritance patterns to gain insights about their phylogeographic history. Phylogenetic and individual-based Bayesian analysis showed weak geographical structure amongst nuclear sequences (autosomal and Z-chromosomal loci). Coalescent analysis revealed high levels of gene flow among mitochondrial populations, even between allopatric populations. These results strongly suggested that male-biased gene flow was responsible for the discordant cytonuclear phylogeographic patterns. Consistent with expectation on the genetic consequence of long-distance male dispersal, mantel tests revealed a significant pattern of isolation by distance for mitochondrial sequences, but failed to provide a similar pattern for nuclear genes within a continuous population; female Black-throated tits showed a stronger but not significantly different relationship of isolation by distance than males when using mitochondrial DNA alone. We discussed the contribution of male juveniles with delayed dispersal to the non-significantly different IBD patterns between sexes. Our results using multilocus genetic data revealed aspects of the complex evolutionary history of Black-throated tits and the important role of long-distance male dispersal in the population structuring.

  15. Adaptive modelling of long-distance wave propagation and fine-scale flooding during the Tohoku tsunami

    Directory of Open Access Journals (Sweden)

    S. Popinet

    2012-04-01

    Full Text Available The 11 March 2011 Tohoku tsunami is simulated using the quadtree-adaptive Saint-Venant solver implemented within the Gerris Flow Solver. The spatial resolution is adapted dynamically from 250 m in flooded areas up to 250 km for the areas at rest. Wave fronts are tracked at a resolution of 1.8 km in deep water. The simulation domain extends over 73° of both latitude and longitude and covers a significant part of the north-west Pacific. The initial wave elevation is obtained from a source model derived using seismic data only. Accurate long-distance wave prediction is demonstrated through comparison with DART buoys timeseries and GLOSS tide gauges records. The model also accurately predicts fine-scale flooding compared to both satellite and survey data. Adaptive mesh refinement leads to orders-of-magnitude gains in computational efficiency compared to non-adaptive methods. The study confirms that consistent source models for tsunami initiation can be obtained from seismic data only. However, while the observed extreme wave elevations are reproduced by the model, they are located further south than in the surveyed data. Comparisons with inshore wave buoys data indicate that this may be due to an incomplete understanding of the local wave generation mechanisms.

  16. Concurrent fatigue and postactivation potentiation during extended interval training in long-distance runners

    Directory of Open Access Journals (Sweden)

    Pedro Ángel Latorre-Román

    2014-12-01

    Full Text Available The purpose of this study is to analyze acute effect of running extended interval training(EIT on vertical jump (VJ and handgrip strength (HS performance in experienced endurance athletes. In order to analyze mechanical parameters of the VJ and HS between runs, sixteen experienced male athletes performed an EIT (4x3x400m. The results show that fatigue induced by EIT does not impair handgrip strength or VJ performance. A significant improvement (p< .05 was noted for VJ due to the postactivation potentiation (PAP phenomenon. A positive correlation (r= .619, p= .011 was found between VJ and lactate. The results suggest that experienced long-distance runners can maintain their strength levels and, consequently, work capacity, despite the induced fatigue by the field training demand. Therefore, VJ performance during EIT can be used as an indicator of muscular adaptations to training and, together, with handgrip strength, become indicators of fatigue. These indicators allow proper prescription training routines.

  17. Testing long-distance modifications of gravity to 100 astronomical units

    CERN Document Server

    Buscaino, Brandon; Graham, Peter W; Gratta, Giorgio; Wiser, Timothy D

    2015-01-01

    There are very few direct experimental tests of the inverse square law of gravity at distances comparable to the scale of the Solar System and beyond. Here we describe a possible space mission optimized to test the inverse square law at a scale of up to 100 AU. For example, sensitivity to a Yukawa correction with a strength of $10^{-7}$ times gravity and length scale of 100 AU is within reach, improving the current state of the art by over two orders of magnitude. This experiment would extend our understanding of gravity to the largest scale that can be reached with a direct probe using known technology. This would provide a powerful test of long-distance modifications of gravity including many theories motivated by dark matter or dark energy.

  18. Toward Long Distance, Sub-diffraction Imaging Using Coherent Camera Arrays

    CERN Document Server

    Holloway, Jason; Sharma, Manoj Kumar; Matsuda, Nathan; Horstmeyer, Roarke; Cossairt, Oliver; Veeraraghavan, Ashok

    2015-01-01

    In this work, we propose using camera arrays coupled with coherent illumination as an effective method of improving spatial resolution in long distance images by a factor of ten and beyond. Recent advances in ptychography have demonstrated that one can image beyond the diffraction limit of the objective lens in a microscope. We demonstrate a similar imaging system to image beyond the diffraction limit in long range imaging. We emulate a camera array with a single camera attached to an X-Y translation stage. We show that an appropriate phase retrieval based reconstruction algorithm can be used to effectively recover the lost high resolution details from the multiple low resolution acquired images. We analyze the effects of noise, required degree of image overlap, and the effect of increasing synthetic aperture size on the reconstructed image quality. We show that coherent camera arrays have the potential to greatly improve imaging performance. Our simulations show resolution gains of 10x and more are achievabl...

  19. Welfare aspects of the long distance transportation of animals — the Animal Transportation Association

    Directory of Open Access Journals (Sweden)

    Tim Harris

    2008-03-01

    Full Text Available The international and long distance movement of animals is a far larger business than most people imagine. Some reasons are outlined in this paper, along with the history of the AATA (Animal [Air] Transportation Association. This trade association has been involved for over 30 years in developing standards and procedures for the movement of all types of animals. The competence of animal handlers is of paramount importance. Competence of flying grooms is assessed by the AATA. This paper is written from the viewpoint of someone who has been a member since the Association's inception. The subject will be of interest to airlines, transporters, veterinarians, farmers, animal relocators, zoological establishments and legislators.

  20. Experimental long-distance decoy-state quantum key distribution based on polarization encoding.

    Science.gov (United States)

    Peng, Cheng-Zhi; Zhang, Jun; Yang, Dong; Gao, Wei-Bo; Ma, Huai-Xin; Yin, Hao; Zeng, He-Ping; Yang, Tao; Wang, Xiang-Bin; Pan, Jian-Wei

    2007-01-05

    We demonstrate the decoy-state quantum key distribution (QKD) with one-way quantum communication in polarization space over 102 km. Further, we simplify the experimental setup and use only one detector to implement the one-way decoy-state QKD over 75 km, with the advantage to overcome the security loopholes due to the efficiency mismatch of detectors. Our experimental implementation can really offer the unconditionally secure final keys. We use 3 different intensities of 0, 0.2, and 0.6 for the light sources in our experiment. In order to eliminate the influences of polarization mode dispersion in the long-distance single-mode optical fiber, an automatic polarization compensation system is utilized to implement the active compensation.

  1. Wind as a Long-Distance Dispersal Vehicle in the Southern Hemisphere

    Science.gov (United States)

    Muñoz, Jesús; Felicísimo, Ángel M.; Cabezas, Francisco; Burgaz, Ana R.; Martínez, Isabel

    2004-05-01

    Anisotropic (direction-dependent) long-distance dispersal (LDD) by wind has been invoked to explain the strong floristic affinities shared among landmasses in the Southern Hemisphere. Its contribution has not yet been systematically tested because of the previous lack of global data on winds. We used global winds coverage from the National Aeronautics and Space Administration SeaWinds scatterometer to test whether floristic similarities of Southern Hemisphere moss, liverwort, lichen, and pteridophyte floras conform better with (i) the anisotropic LDD hypothesis, which predicts that connection by ``wind highways'' increases floristic similarities, or (ii) a direction-independent LDD hypothesis, which predicts that floristic similarities among sites increase with geographic proximity. We found a stronger correlation of floristic similarities with wind connectivity than with geographic proximities, which supports the idea that wind is a dispersal vehicle for many organisms in the Southern Hemisphere.

  2. Long distance root-shoot signalling in plant-insect community interactions.

    Science.gov (United States)

    Soler, Roxina; Erb, Matthias; Kaplan, Ian

    2013-03-01

    Plants mediate interactions between insects, including leaf- and root-feeders; yet the underlying mechanisms and connection with ecological theory remain unresolved. In this review, based on novel insights into long-distance (i.e., leaf-leaf, root-shoot) defence signalling, we explore the role of phytohormones in driving broad-scale patterns of aboveground-belowground interactions that can be extrapolated to general plant-insect relationships. We propose that the outcome of intra-feeding guild interactions is generally negative due to induction of similar phytohormonal pathways, whereas between-guild interactions are often positive due to negative signal crosstalk. However, not all outcomes could be explained by feeding guild; we argue that future studies should target ecologically representative plant-insect systems, distinguish subguilds, and include plant growth hormones to improve our understanding of plant-mediated interactions.

  3. Long-distance quantum state transfer through cavity-assisted interaction

    Institute of Scientific and Technical Information of China (English)

    Li Yu-Ning; Mei Feng; Yu Ya-Fei; and Zhang Zhi-Ming

    2011-01-01

    We propose a scheme for long-distance quantum state transfer between different atoms based on cavity-assisted interactions.In our scheme,a coherent optical pulse sequentially interacts with two distant atoms trapped in separated cavities. Through the measurement of the state of the first atom and the homodyne detection of the final output coherent light,the quantum state can be transferred into the second atom with a success probability of unity and a fidelity of unity.In addition,our scheme neither requires the high-Q cavity working in the strong coupling regime nor employs the single-photon quantum channel,which greatly relaxes the experimental requirements.

  4. Non-contact transmittance photoplethysmographic imaging (PPGI) for long-distance cardiovascular monitoring

    CERN Document Server

    Amelard, Robert; Kazemzadeh, Farnoud; Pfisterer, Kaylen J; Lin, Bill S; Wong, Alexander; Clausi, David A

    2015-01-01

    Photoplethysmography (PPG) devices are widely used for monitoring cardiovascular function. However, these devices require skin contact, which restrict their use to at-rest short-term monitoring using single-point measurements. Photoplethysmographic imaging (PPGI) has been recently proposed as a non-contact monitoring alternative by measuring blood pulse signals across a spatial region of interest. Existing systems operate in reflectance mode, of which many are limited to short-distance monitoring and are prone to temporal changes in ambient illumination. This paper is the first study to investigate the feasibility of long-distance non-contact cardiovascular monitoring at the supermeter level using transmittance PPGI. For this purpose, a novel PPGI system was designed at the hardware and software level using ambient correction via temporally coded illumination (TCI) and signal processing for PPGI signal extraction. Experimental results show that the processing steps yield a substantially more pulsatile PPGI si...

  5. Does size and buoyancy affect the long-distance transport of floating debris?

    Science.gov (United States)

    Ryan, Peter G.

    2015-08-01

    Floating persistent debris, primarily made from plastic, disperses long distances from source areas and accumulates in oceanic gyres. However, biofouling can increase the density of debris items to the point where they sink. Buoyancy is related to item volume, whereas fouling is related to surface area, so small items (which have high surface area to volume ratios) should start to sink sooner than large items. Empirical observations off South Africa support this prediction: moving offshore from coastal source areas there is an increase in the size of floating debris, an increase in the proportion of highly buoyant items (e.g. sealed bottles, floats and foamed plastics), and a decrease in the proportion of thin items such as plastic bags and flexible packaging which have high surface area to volume ratios. Size-specific sedimentation rates may be one reason for the apparent paucity of small plastic items floating in the world’s oceans.

  6. [Theory of long-distance electron transfer in nanoscale biological structures].

    Science.gov (United States)

    Krasil'nikov, P M

    2011-01-01

    Macromolecular biological systems accomplishing the directed electron transfer are nano-sized structures. The distance between carrier molecules (cofactors), which represent practically isolated electron localization centers, reaches tens of angstroms. The electron transfer theory based on the concept of delocalized electron states, which is conventionally used in biophysics, is unable to adequately interpret the results of concrete observations in many cases. On the basis of the theory of electronic transitions in the case of localized states, developed in the physics of disorder matter, a mechanism of long distance electron transfer in biological systems is suggested. The molecular relaxation of the microenvironment of electron localization centers that accompanies the electron transfer process is also considered.

  7. Historical DNA documents long-distance natal homing in marine fish.

    Science.gov (United States)

    Bonanomi, Sara; Overgaard Therkildsen, Nina; Retzel, Anja; Berg Hedeholm, Rasmus; Pedersen, Martin Waever; Meldrup, Dorte; Pampoulie, Christophe; Hemmer-Hansen, Jakob; Grønkjaer, Peter; Nielsen, Einar Eg

    2016-06-01

    The occurrence of natal homing in marine fish remains a fundamental question in fish ecology as its unequivocal demonstration requires tracking of individuals from fertilization to reproduction. Here, we provide evidence of long-distance natal homing (>1000 km) over more than 60 years in Atlantic cod (Gadus morhua), through genetic analysis of archived samples from marked and recaptured individuals. Using a high differentiation single-nucleotide polymorphism assay, we demonstrate that the vast majority of cod tagged in West Greenland and recaptured on Icelandic spawning grounds belonged to the Iceland offshore population, strongly supporting a hypothesis of homing. The high degree of natal fidelity observed provides the evolutionary settings for development of locally adapted populations in marine fish and emphasize the need to consider portfolio effects in marine fisheries management strategies.

  8. Overcoming Challenges: Breathing Hope Through Teamwork and Long-Distance Thoracic Transplantation.

    Science.gov (United States)

    Villalon, Ernie

    2016-09-01

    Lung donation and transplantation is increasing in volume annually, yet there continues to be a shortage of available organs for transplant. Despite this shortage, suitable lungs are occasionally not transplanted due to logistical issues. Issues such as time and distance can be a major barrier in deceased donor organ recovery and transplantation. This single case study serves as an example of the teamwork and cooperation that resulted in the successful transplantation of lungs in spite of long-distance logistical issues between the donor and the recipient. All of the members who contributed to this collaboration recognized the need and urgency to overcome these challenges. The organ procurement organization's collaboration with multiple transplant centers across multiple regions resulted in a successful outcome for the lung recipient.

  9. Long-distance electron transfer by cable bacteria in aquifer sediments

    DEFF Research Database (Denmark)

    Müller, Hubert; Bosch, Julian; Griebler, Christian

    2016-01-01

    The biodegradation of organic pollutants in aquifers is often restricted to the fringes of contaminant plumes where steep countergradients of electron donors and acceptors are separated by limited dispersive mixing. However, long-distance electron transfer (LDET) by filamentous ‘cable bacteria’ has...... recently been discovered in marine sediments to couple spatially separated redox half reactions over centimeter scales. Here we provide primary evidence that such sulfur-oxidizing cable bacteria can also be found at oxic–anoxic interfaces in aquifer sediments, where they provide a means for the direct...... of oxygen and sulfide by 9 mm together with a pH profile characteristic for sulfur oxidation by LDET. Bacterial filaments, which were highly abundant in the suboxic zone, were identified by sequencing of 16S rRNA genes and fluorescence in situ hybridization (FISH) as cable bacteria belonging...

  10. Long-distance electron transfer by cable bacteria in aquifer sediments

    DEFF Research Database (Denmark)

    Damgaard, Lars Riis; Nielsen, Lars Peter

    2016-01-01

    The biodegradation of organic pollutants in aquifers is often restricted to the fringes of contaminant plumes where steep countergradients of electron donors and acceptors are separated by limited dispersive mixing. However, long-distance electron transfer (LDET) by filamentous ‘cable bacteria’ has...... recently been discovered in marine sediments to couple spatially separated redox half reactions over centimeter scales. Here we provide primary evidence that such sulfur-oxidizing cable bacteria can also be found at oxic–anoxic interfaces in aquifer sediments, where they provide a means for the direct...... of oxygen and sulfide by 9 mm together with a pH profile characteristic for sulfur oxidation by LDET. Bacterial filaments, which were highly abundant in the suboxic zone, were identified by sequencing of 16S rRNA genes and fluorescence in situ hybridization (FISH) as cable bacteria belonging...

  11. Cable bacteria associated with long-distance electron transport in New England salt marsh sediment.

    Science.gov (United States)

    Larsen, Steffen; Nielsen, Lars Peter; Schramm, Andreas

    2015-04-01

    Filamentous Desulfobulbaceae have been proposed as 'cable bacteria', which electrically couple sulfide oxidation and oxygen reduction in marine sediment and thereby create a centimetre-deep suboxic zone. We incubated New England salt marsh sediment and found long-distance electron transport across 6 mm and 16S rRNA genes identical to those of previously observed cable bacteria in Aarhus Bay sediment incubations. Cable bacteria density in sediment cores was quantified by fluorescence in situ hybridization. In contrast to the coastal, subtidal sediments with short-termed blooms of cable bacteria based on rapidly depleted iron sulfide pools, the salt marsh cable community was based on ongoing sulfate reduction and therefore probably more persistent. Previously observed seasonal correlation between Desulfobulbaceae dominance and extensive reduced sulfur oxidation in salt marshes suggest that cable bacteria at times may have an important role in situ.

  12. Long-distance transmission of light in a scintillator-based radiation detector

    Energy Technology Data Exchange (ETDEWEB)

    Dowell, Jonathan L.; Talbott, Dale V.; Hehlen, Markus P.

    2017-07-11

    Scintillator-based radiation detectors capable of transmitting light indicating the presence of radiation for long distances are disclosed herein. A radiation detector can include a scintillator layer and a light-guide layer. The scintillator layer is configured to produce light upon receiving incident radiation. The light-guide layer is configured to receive light produced by the scintillator layer and either propagate the received light through the radiation detector or absorb the received light and emit light, through fluorescence, that is propagated through the radiation detector. A radiation detector can also include an outer layer partially surrounding the scintillator layer and light-guide layer. The index of refraction of the light-guide layer can be greater than the index of refraction of adjacent layers.

  13. Postglacial population expansion drives the evolution of long-distance migration in a songbird.

    Science.gov (United States)

    Milá, Borja; Smith, Thomas B; Wayne, Robert K

    2006-11-01

    The evolution of long-distance migratory behavior from sedentary populations is a central problem in studies of animal migration. Three crucial issues that remain unresolved are: (1) the biotic and abiotic factors promoting evolution of migratory behavior, (2) the geographic origin of ancestral sedentary populations, and (3) the time scale over which migration evolves. We test the role of postglacial population expansions during the Quaternary in driving the evolution of songbird migration against prevailing views favoring the role of intraspecific competition. In contrast to previous attempts to investigate these questions using interspecific phylogenies, we adopt an intraspecific approach and examine the phylogeography of a North American songbird, the chipping sparrow (Spizella passerina), which exhibits both long-distance migratory behavior in temperate North America and sedentary behavior in Mexico and Central America. We show that migratory populations descend from sedentary populations in southern Mexico and that migration has evolved as a result of a northward population expansion into temperate North America since the last glacial maximum 18,000 years ago. Migration appears to have evolved rapidly in some species as populations colonized areas of high seasonality in the temperate zone. The phylogeography of the yellow-eyed junco (Junco phaeonotus), a strictly sedentary species, provides a null model supporting the view that northward range expansions were driven solely by environmental factors and not by a predisposition to evolve migratory behavior. These results provide the strongest evidence to date that historical climate patterns can drive the rapid evolution of avian migration in natural populations, and they suggest a general mechanism for the repeated evolution of migration within and across bird lineages.

  14. Long-distance signals positively regulate the expression of iron uptake genes in tobacco roots.

    Science.gov (United States)

    Enomoto, Yusuke; Hodoshima, Hirotaka; Shimada, Hiroaki; Shoji, Kazuhiro; Yoshihara, Toshihiro; Goto, Fumiyuki

    2007-12-01

    Long-distance signals generated in shoots are thought to be associated with the regulation of iron uptake from roots; however, the signaling mechanism is still unknown. To elucidate whether the signal regulates iron uptake genes in roots positively or negatively, we analyzed the expressions of two representative iron uptake genes: NtIRT1 and NtFRO1 in tobacco (Nicotiana tabacum L.) roots, after shoots were manipulated in vitro. When iron-deficient leaves were treated with Fe(II)-EDTA, the expressions of both genes were significantly reduced; nevertheless iron concentration in the roots maintained a similar level to that in roots grown under iron-deficient conditions. Next, all leaves from tobacco plants grown under the iron-deficient condition were excised. The expression of two genes were quickly reduced below half within 2 h after the leaf excision and gradually disappeared by the end of a 24-h period. The NtIRT1 expression was compared among the plants whose leaves were cut off in various patterns. The expression increased in proportion to the dry weight of iron-deficient leaves, although no relation was observed between the gene expression and the position of excised leaves. Interestingly, the NtIRT1 expression in hairy roots increased under the iron-deficient condition, suggesting that roots also have the signaling mechanism of iron status as well as shoots. Taken together, these results indicate that the long-distance signal generated in iron-deficient tissues including roots is a major factor in positive regulation of the expression of NtIRT1 and NtFRO1 in roots, and that the strength of the signal depends on the size of plants.

  15. Long-distance transport of L-ascorbic acid in potato

    Directory of Open Access Journals (Sweden)

    Alberino Salvatore

    2004-09-01

    Full Text Available Abstract Background Following on from recent advances in plant AsA biosynthesis there is increasing interest in elucidating the factors contributing to the L-ascorbic acid (AsA content of edible crops. One main objective is to establish whether in sink organs such as fruits and tubers, AsA is synthesised in situ from imported photoassimilates or synthesised in source tissues and translocated via the phloem. In the current work we test the hypothesis that long-distance transport is involved in AsA accumulation within the potato tuber, the most significant source of AsA in the European diet. Results Using the EDTA exudation technique we confirm the presence of AsA in the phloem of potato plants and demonstrate a correlation between changes in the AsA content of source leaves and that of phloem exudates. Comparison of carboxyflourescein and AgNO3 staining is suggestive of symplastic unloading of AsA in developing tubers. This hypothesis was further supported by the changes in AsA distribution during tuber development which closely resembled those of imported photoassimilates. Manipulation of leaf AsA content by supply of precursors to source leaves resulted in increased AsA content of developing tubers. Conclusion Our data provide strong support to the hypothesis that long-distance transport of AsA occurs in potato. We also show that phloem AsA content and AsA accumulation in sink organs can be directly increased via manipulation of AsA content in the foliage. We are now attempting to establish the quantitative contribution of imported AsA to overall AsA accumulation in developing potato tubers via transgenic approaches.

  16. Phloem long-distance delivery of FLOWERING LOCUS T (FT) to the apex.

    Science.gov (United States)

    Yoo, Soo-Cheul; Chen, Cheng; Rojas, Maria; Daimon, Yasufumi; Ham, Byung-Kook; Araki, Takashi; Lucas, William J

    2013-08-01

    Cucurbita moschata FLOWERING LOCUS T-LIKE 2 (hereafter FTL2) and Arabidopsis thaliana (Arabidopsis) FLOWERING LOCUS T (FT), components of the plant florigenic signaling system, move long-distance through the phloem from source leaves to the vegetative apex where they mediate floral induction. The mechanisms involved in long-distance trafficking of FT/FTL2 remain to be elucidated. In this study, we identified the critical motifs on both FT and FTL2 required for cell-to-cell trafficking through mutant analyses using a zucchini yellow mosaic virus expression vector. Western blot analysis, performed on phloem sap collected from just beneath the vegetative apex of C. moschata plants, established that all mutant proteins tested retained the ability to enter the phloem translocation stream. However, immunolocalization studies revealed that a number of these FTL2/FT mutants were defective in the post-phloem zone, suggesting that a regulation mechanism for FT trafficking exists in the post-phloem unloading step. The selective movements of FT/FTL2 were further observed by microinjection and trichome rescue studies, which revealed that FT/FTL2 has the ability to dilate plasmodesmata microchannels during the process of cell-to-cell trafficking, and various mutants were compromised in their capacity to traffic through plasmodesmata. Based on these findings, a model is presented to account for the mechanism by which FT/FTL2 enters the phloem translocation stream and subsequently exits the phloem and enters the apical tissue, where it initiates the vegetative to floral transition.

  17. Long distance energy transfer in a polymer matrix doped with a perylene dye.

    Science.gov (United States)

    Fennel, Franziska; Lochbrunner, Stefan

    2011-02-28

    Exciton migration over long distances is a key issue for various applications in organic electronics. We investigate a disordered material system which has the potential for long exciton diffusion lengths in combination with a high versatility. The perylene bisimide dye Perylene Red is incorporated in a polymer matrix with a high concentration. The dye molecules represent active sites with a narrow energy distribution for the electronically excited states. Excitons can be efficiently exchanged between them by Förster resonance energy transfer (FRET). The narrow energy distribution reduces drastically the trapping probability of the excitons compared to polymers and allows for long transfer distances. To characterize the mobility of the excitons and their diffusion length the dye Oxazine 1 is added as an acceptor in low concentration and the transfer probability to the acceptor is determined by measuring the reduction of Perylene Red fluorescence. The quenched quantum yield is measured for dye concentrations varying from 0.05 M to 0.15 M for Perylene Red and from 0.3 mM to 3 mM for Oxazine 1. The experimental results are compared to a model which assumes that excitons can diffuse through the material by FRET between Perylene Red sites and are trapped at an acceptor with a final hetero FRET step. We find a quite good match between theory and experiment though the observed diffusion constant is about two times smaller than the calculated one. The exciton diffusion length extracted from the data is 30 nm for a Perylene Red concentration of 0.1 M and demonstrates that long distance energy transfer is possible in this disordered material system.

  18. New aspects of phloem-mediated long-distance lipid signaling in plants

    Directory of Open Access Journals (Sweden)

    Urs Florian Benning

    2012-03-01

    Full Text Available Plants are sessile and cannot move to appropriate hiding places or feeding grounds to escape adverse conditions. As a consequence, they evolved mechanisms to detect changes in their environment, communicate these to different organs, and adjust development accordingly. These adaptations include two long-distance transport systems which are essential in plants: the xylem and the phloem. The phloem serves as a major trafficking pathway for assimilates, viruses, RNA, plant hormones, metabolites, and proteins with functions ranging from synthesis to metabolism to signaling. The study of signaling compounds within the phloem is essential for our understanding of plant communication of environmental cues. Determining the nature of signals and the mechanisms by which they are communicated through the phloem will lead to a more complete understanding of plant development and plant responses to stress. In our analysis of Arabidopsis phloem exudates, we had identified several lipid-binding proteins as well as fatty acids and lipids. The latter are not typically expected in the aqueous environment of sieve elements. Hence, lipid transport in the phloem has been given little attention until now. Long-distance transport of hydrophobic compounds in an aqueous system is not without precedence in biological systems: a variety of lipids is found in human blood and are often bound to proteins. Some lipid-protein complexes are transported to other tissues for storage, use, modification, or degradation, others serve as messengers and modulate transcription factor activity. By simple analogy it raises the possibility that lipids and the respective lipid-binding proteins in the phloem serve similar functions in plants and play an important role in stress and developmental signaling. Here, we introduce the lipid-binding proteins and the lipids we found in the phloem and discuss the possibility that they may play an important role in developmental and stress signaling.

  19. Long-distance, graft-transmissible action of Arabidopsis FLOWERING LOCUS T protein to promote flowering.

    Science.gov (United States)

    Notaguchi, Michitaka; Abe, Mitsutomo; Kimura, Takahiro; Daimon, Yasufumi; Kobayashi, Toshinori; Yamaguchi, Ayako; Tomita, Yuki; Dohi, Koji; Mori, Masashi; Araki, Takashi

    2008-11-01

    Day length perceived by a leaf is a major environmental factor that controls the timing of flowering. It has been believed that a mobile, long-distance signal called florigen is produced in the leaf under inductive day length conditions, and is transported to the shoot apex where it triggers floral morphogenesis. Grafting experiments have shown that florigen is transmissible from a donor plant that has been subjected to inductive day length to an uninduced recipient plant. However, the nature of florigen has long remained elusive. Arabidopsis FLOWERING LOCUS T (FT) is expressed in cotyledons and leaves in response to inductive long days (LDs). FT protein, with a basic region/leucine zipper (bZIP) transcription factor FD, acts in the shoot apex to induce target meristem identity genes such as APETALA1 (AP1) and initiates floral morphogenesis. Recent studies have provided evidence that the FT protein in Arabidopsis and corresponding proteins in other species are an important part of florigen. Our work shows that the FT activity, either from overexpressing or inducible transgenes or from the endogenous gene, to promote flowering is transmissible through a graft junction, and that an FT protein with a T7 tag is transported from a donor scion to the apical region of recipient stock plants and becomes detectable within a day or two. The sequence and structure of mRNA are not of critical importance for the long-distance action of the FT gene. These observations led to the conclusion that the FT protein, but not mRNA, is the essential component of florigen.

  20. REPRODUCTIVE SYSTEM AND POLLEN FLOW IN PROGENIES OF Qualea grandiflora Mart., A TYPICAL SPECIES OF THE BRAZILIAN CERRADO

    Directory of Open Access Journals (Sweden)

    Lia Maris Orth Ritter Antiqueira

    2015-04-01

    Full Text Available This study analyzed the reproductive system and the pollen dispersion pattern of Qualea grandiflora progenies. This is a typical species from the Brazilian Cerrado about which there are not too many studies from the genetics point of view. The study was conducted in an area of 2.2 hectares located in the Conservation Unit managed by the Forest Institute of the state of São Paulo, Brazil (Assis State Forest. Total genomic DNA of 300 seeds from 25 plants (12 seeds from each plant was extracted and amplified using specific primers to obtain microsatellite markers. Results showed that selfing is frequent among adults and progenies, and the species reproduces by outcrossing between related and unrelated individuals (0.913. The single-locus outcrossing rate was 0.632, which indicates that mating between unrelated individuals is more frequent than between related plants. The selfing rate was low (0.087, that is, the species is allogamous and self-fertilization is reduced. About 35% of the plants in the progenies were full-sibs, and about 57%, half-sibs. Besides, about 8% of the progenies were selfing siblings. The genetic differentiation coefficient within progenies was 0.139, whereas the fixation rate was about 27%. The estimate of the effective size revealed that the genetic representativeness of descent was lower than expected in random mating progenies: The analyzed samples corresponded to only 13.2 individuals of an ideal panmictic population. In environmental recovery programs, seeds, preferably from different fruits, should be collected from 95 trees to preserve the genetic diversity of the species.

  1. Folding of Pollen Grains

    Science.gov (United States)

    Katifori, Eleni; Alben, Silas; Cerda, Enrique; Nelson, David; Dumais, Jacques

    2008-03-01

    At dehiscence, which occurs when the anther reaches maturity and opens, pollen grains dehydrate and their volume is reduced. The pollen wall deforms to accommodate the volume loss, and the deformation pathway depends on the initial turgid pollen grain geometry and the mechanical properties of the pollen wall. We demonstrate, using both experimental and theoretical approaches, that the design of the apertures (areas on the pollen wall where the stretching and the bending modulus are reduced) is critical for controlling the folding pattern, and ensures the pollen grain viability. An excellent fit to the experiments is obtained using a discretized version of the theory of thin elastic shells.

  2. Allergenic pollen and pollen allergy in Europe.

    Science.gov (United States)

    D'Amato, G; Cecchi, L; Bonini, S; Nunes, C; Annesi-Maesano, I; Behrendt, H; Liccardi, G; Popov, T; van Cauwenberge, P

    2007-09-01

    The allergenic content of the atmosphere varies according to climate, geography and vegetation. Data on the presence and prevalence of allergenic airborne pollens, obtained from both aerobiological studies and allergological investigations, make it possible to design pollen calendars with the approximate flowering period of the plants in the sampling area. In this way, even though pollen production and dispersal from year to year depend on the patterns of preseason weather and on the conditions prevailing at the time of anthesis, it is usually possible to forecast the chances of encountering high atmospheric allergenic pollen concentrations in different areas. Aerobiological and allergological studies show that the pollen map of Europe is changing also as a result of cultural factors (for example, importation of plants such as birch and cypress for urban parklands), greater international travel (e.g. colonization by ragweed in France, northern Italy, Austria, Hungary etc.) and climate change. In this regard, the higher frequency of weather extremes, like thunderstorms, and increasing episodes of long range transport of allergenic pollen represent new challenges for researchers. Furthermore, in the last few years, experimental data on pollen and subpollen-particles structure, the pathogenetic role of pollen and the interaction between pollen and air pollutants, gave new insights into the mechanisms of respiratory allergic diseases.

  3. Long-distance swimming by polar bears (Ursus maritimus) of the southern Beaufort Sea during years of extensive open water

    Science.gov (United States)

    2014-01-01

    Polar bears (Ursus maritimus Phipps, 1774) depend on sea ice for catching marine mammal prey. Recent sea-ice declines have been linked to reductions in body condition, survival, and population size. Reduced foraging opportunity is hypothesized to be the primary cause of sea-ice-linked declines, but the costs of travel through a deteriorated sea-ice environment also may be a factor. We used movement data from 52 adult female polar bears wearing Global Positioning System (GPS) collars, including some with dependent young, to document long-distance swimming (>50 km) by polar bears in the southern Beaufort and Chukchi seas. During 6 years (2004-2009), we identified 50 long-distance swims by 20 bears. Swim duration and distance ranged from 0.7 to 9.7 days (mean = 3.4 days) and 53.7 to 687.1 km (mean = 154.2 km), respectively. Frequency of swimming appeared to increase over the course of the study. We show that adult female polar bears and their cubs are capable of swimming long distances during periods when extensive areas of open water are present. However, long-distance swimming appears to have higher energetic demands than moving over sea ice. Our observations suggest long-distance swimming is a behavioral response to declining summer sea-ice conditions.

  4. Safety of long-distance pipelines. Probabilistic and deterministic aspects; Sicherheit von Rohrfernleitungen. Probabilistik und Deterministik im Vergleich

    Energy Technology Data Exchange (ETDEWEB)

    Hollaender, Robert [Leipzig Univ. (Germany). Inst. fuer Infrastruktur und Ressourcenmanagement

    2013-03-15

    The Committee for Long-Distance Pipelines (Berlin, Federal Republic of Germany) reported on the relation between deterministic and probabilistic approaches in order to contribute to a better understanding of the safety management of long-distance pipelines. The respective strengths and weaknesses as well as the deterministic and probabilistic fundamentals of the safety management are described. The comparison includes fundamental aspects, but is essentially determined by the special character of the technical plant 'long-distance pipeline' as an infrastructure project in the area. This special feature results to special operation conditions and related responsibilities. However, our legal system 'long-distance pipeline' does not grant the same legal position in comparison to other infrastructural facilities such as streets and railways. Thus, the question whether and in what manner the impacts from the land-use in the environment of long-distance pipelines have to be considered is again and again the initial point for the discussion on probabilistic and deterministic approaches.

  5. Factores que afectan al rendimiento en carreras de fondo. [Factors affecting long-distance running performance].

    Directory of Open Access Journals (Sweden)

    Ana Ogueta-Alday

    2016-07-01

    Full Text Available Las carreras de fondo (comprendidas entre los 5 km hasta la maratón han crecido en España tanto en número como en participación. Esto ha suscitado un gran interés en entrenadores y deportistas, que solicitan información y formación sobre los diferentes factores que afectan al rendimiento. Ante esta demanda, el número de investigaciones ha aumentado notablemente. El objetivo de esta revisión bibliográfica ha sido analizar los factores que afectan al rendimiento en carreras de fondo desde sus diferentes perspectivas. Para ello, se ha realizado una revisión bibliográfica en 3 bases de datos (Medline, SportDiscus y Google Scholar y los factores han sido clasificados en 5 grandes grupos, subdivididos a su vez en diferentes apartados: 1- ambientales (aire/viento, temperatura, humedad, altura y pendiente del terreno, 2- ligados al entrenamiento (entrenamiento de resistencia, fuerza, en ambientes calurosos y en altura, 3- fisiológicos (VO2max, umbrales ventilatorios, economía de carrera, edad, género, tipos de fibras musculares, fatiga y raza, 4- biomecánicos (antropometría, leg-stiffness, flexibilidad, patrón de pisada, calzado, ortesis plantares y parámetros espacio-temporales y 5- psicológicos (estrategias de intervención, dirección de la atención y música. La influencia de algunos de éstos sobre el rendimiento es ampliamente conocida; sin embargo, en el caso de algunos factores psicológicos (dirección de la atención y música y biomecánicos (patrón de pisada y parámetros espacio-temporales el número de estudios es escaso o los resultados poco concluyentes. La realización de más estudios, conjuntamente con el avance de las nuevas tecnologías y sistemas de medición, permitirá un mejor conocimiento sobre la temática. Abstract The number of competitions and participation on long-distance races (from 5 km to the marathon in Spain has grown significantly during the last few years. Due to this popularity, both coaches

  6. Plant genetics. Pollen clusters.

    Science.gov (United States)

    Smyth, D R

    1994-09-01

    New Arabidopsis mutations that result in all four products of meiosis being held together as a tetrad of fused pollen grains may facilitate genetic mapping and lead to new insights into pollen biology.

  7. Pollen dispersal analysis using DNA markers

    Directory of Open Access Journals (Sweden)

    Wei Zhou

    2014-01-01

    Full Text Available Modes of pollen dispersal are important for plant ecology, conservation, and evolutionary biology as pollen-mediated gene flow connects one generation of sexually-reproducing plants to the next. With the development of DNA molecular techniques, molecular markers (especially microsatellite markers have replaced traditional physical markers for pollen flow analysis. Methods of paternity assignment with maximum likelihood and Bayesian inference have greatly improved the estimation of pollen flow characteristics with regard to direction, distance, and strength. Pollen dispersal curves have been characterized by single parameter, two-parameter, multi-parameter, and two-component composite models to better evaluate the shape of dispersal distributions. These innovative techniques and methods have been successfully applied to assess pollination patterns in studies of plant sexual polymorphism, population connectivity, and natural hybridization, which, in turn, have provided important insights into basic theories of evolution, ecology, and conservation. In the coming years, high-throughput sequencing technologies are expected to accelerate the application of molecular marker-based pollen flow analysis across a wide range of plant taxa.

  8. The design, construction, and operation of long-distance high-voltage electricity transmission technologies.

    Energy Technology Data Exchange (ETDEWEB)

    Molburg, J. C.; Kavicky, J. A.; Picel, K. C.

    2008-03-03

    This report focuses on transmission lines, which operate at voltages of 115 kV and higher. Currently, the highest voltage lines comprising the North American power grid are at 765 kV. The grid is the network of transmission lines that interconnect most large power plants on the North American continent. One transmission line at this high voltage was built near Chicago as part of the interconnection for three large nuclear power plants southwest of the city. Lines at this voltage also serve markets in New York and New England, also very high demand regions. The large power transfers along the West Coast are generally at 230 or 500 kV. Just as there are practical limits to centralization of power production, there are practical limits to increasing line voltage. As voltage increases, the height of the supporting towers, the size of the insulators, the distance between conductors on a tower, and even the width of the right-of-way (ROW) required increase. These design features safely isolate the electric power, which has an increasing tendency to arc to ground as the voltage (or electrical potential) increases. In addition, very high voltages (345 kV and above) are subject to corona losses. These losses are a result of ionization of the atmosphere, and can amount to several megawatts of wasted power. Furthermore, they are a local nuisance to radio transmission and can produce a noticeable hum. Centralized power production has advantages of economies of scale and special resource availability (for instance, hydro resources), but centralized power requires long-distance transfers of power both to reach customers and to provide interconnections for reliability. Long distances are most economically served at high voltages, which require large-scale equipment and impose a substantial footprint on the corridors through which power passes. The most visible components of the transmission system are the conductors that provide paths for the power and the towers that keep these

  9. Hepatitis C virus infection in Brazilian long-distance truck drivers

    Directory of Open Access Journals (Sweden)

    Freitas Nara R

    2010-08-01

    Full Text Available Abstract Hepatitis C virus (HCV infection is a global public health problem. Long-distance truck drivers live apart from their family for long periods of time, a lifestyle that favors at-risk behaviors such as unprotected sex with multiple partners and illicit drug use. As data concerning HCV infection in this population are still rare, this paper aims to investigate the prevalence, genotypes/subtypes, and the factors associated with HCV infection in long-distance truck drivers in Brazil. A cross-sectional survey was carried out with 641 Brazilian long-truck drivers who were recruited at a major truck stop located at kilometer 1,296 of the BR-153 highway, which is considered to be one of the longest roads in Brazil. All individuals were interviewed, and their serum samples were tested for the presence of antibodies to HCV (anti-HCV by ELISA and immunoblot. Anti-HCV positive samples were tested for HCV RNA by PCR amplification of the 5' NC and NS5B regions and were genotyped using the LiPA assay and nucleotide sequencing, respectively. Factors associated with HCV infection were identified with logistic regression. The prevalence of HCV infection was 1.4% (95% CI: 0.7-2.8. History of blood transfusion, sharing of personal hygiene tools, illicit drug use and HBV status were factors independently associated with HCV infection in the study population. HCV RNA was detected in 8/9 anti-HCV positive samples, in which genotypes 1 (n = 3, 2 (n = 2, and 3 (n = 3 were determined by LiPA. Using phylogenetic tree analysis of the NS5B region, subtypes 1a (n = 1, 1b (n = 2, 2b (n = 2 and 3a (n = 3 were identified. These data show that the prevalence of HCV infection among Brazilian truck drivers was similar to that observed for the general population. History of blood transfusion, sharing of personal hygiene tools, illicit drug use and HBV status were predictors of HCV infection. The HCV genotypes/subtypes identified in the study population are consistent with

  10. Safety culture in activities involving ionizing radiation long-distance courses for industrial applications

    Energy Technology Data Exchange (ETDEWEB)

    Sahyun, A.; Sordi, G.M.; Ghobril, C.N. [ATOMO - Radioprotecao e Seguranca Nuclear S/C Ltda, Sao Paulo, SP (Brazil); Sanches, M.P. [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Sao Paulo, SP (Brazil); Levy, P.J.; Levy, D.S. [Omiccron Programacao Grafica, Sao Paulo, SP (Brazil)

    2006-07-01

    A.T.O.M.O. is a firm with long experience in the layout and coordination of Radiological Protection courses and, for this reason, has developed long-distance courses, both in Portuguese and in English, using multi-media resources already available for the areas of Gamma-graphy, Nuclear Gauges, Accelerators and Large Irradiators. On developing this project, we focused companies and their personnel to be trained, aiming avoiding their relocation and providing the comfortable of studying at their more convenient time. O.m.i.c.r.o.m., a multimedia firm, our partner in this project, has been responsible for the course program and design. This work consisted in the adaptation of the traditional material for electronic language, through links, hot words and icons especially developed for additional information. Besides images and graphics from the original handouts, animations were developed at O.m.i.c.r.o.m. studios, explaining the procedures with more details and simplifying the comprehension of more complex subjects. For enhancing the Cd Rom, slides were produced, where the pictures move automatically as the explanations are narrated. The Cd also comprises some videos, where the students may visualize practically the complex procedures, which are extremely important. At the end of each topic, the students evaluate their knowledge through multiple choice tests, which deal with the subject studied in the related chapter. This and other highly updated resources are utilized for assuring a better learning. The Cd is not only an electronic handout, but a long-distance course providing weekly support for the students, through Internet, direct access to the instructors by e-mails or chat, previously arranged, access to a data bank constantly updated for more frequent questions, plus link addresses and pages of interest for radiological protection. The tests are taken at the end of each module, before starting the following one. Each module comprises several chapters, totaling

  11. 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

  12. Transport logistics in pollen tubes.

    Science.gov (United States)

    Chebli, Youssef; Kroeger, Jens; Geitmann, Anja

    2013-07-01

    Cellular organelles move within the cellular volume and the effect of the resulting drag forces on the liquid causes bulk movement in the cytosol. The movement of both organelles and cytosol leads to an overall motion pattern called cytoplasmic streaming or cyclosis. This streaming enables the active and passive transport of molecules and organelles between cellular compartments. Furthermore, the fusion and budding of vesicles with and from the plasma membrane (exo/endocytosis) allow for transport of material between the inside and the outside of the cell. In the pollen tube, cytoplasmic streaming and exo/endocytosis are very active and fulfill several different functions. In this review, we focus on the logistics of intracellular motion and transport processes as well as their biophysical underpinnings. We discuss various modeling attempts that have been performed to understand both long-distance shuttling and short-distance targeting of organelles. We show how the combination of mechanical and mathematical modeling with cell biological approaches has contributed to our understanding of intracellular transport logistics.

  13. High pressure long distance pipelines: technical - economic analysis; Les conduites a haute pression pour le transport a grande distance de gaz naturel: analyse technico-economique

    Energy Technology Data Exchange (ETDEWEB)

    Donati, E.; Ercolani, D. [Snamprogetti (Italy)

    2000-07-01

    Over the second half of the Nineties, Snamprogetti and Snam, with the cooperation of ENI Divisione Agip, Saipem and EniTecnologie, have been working for a new concept of long distance (LD) transportation of natural gas via cross country pipelines, based on high pressure (HP) larger than the traditional 7.5 to 10 MPa, here called low pressure (LP), and advanced technologies. This paper describes the economic advantages of the new long distance high pressure (LDHP) gas transportation concept, in terms of investment and operating costs; the findings of the application of a mathematical model developed for the determination of the optimum pipe diameter and number of compression stations for both HP and LP alternatives are discussed. The economic comparison, referred to a representative case i.e. a transmission system of 5,000 km for a specified transport capacity of 15 to 30 x 10{sup 9} Sm{sup 3}/y, shows that the competitiveness of LDHP transportation increases with the increase of the flow rates, reaching a very remarkable advantage for quantities exceeding 10 x 10{sup 9} Sm{sup 3}/y. At present ENI Group companies are engaged in further development focused on the application of high grade steels (X-100), and aiming at obtaining further cost reduction while both ensuring the required system reliability and meeting the specified safety requirements. (authors)

  14. Comparison of pollen gene flow among four European beech (Fagus sylvatica L.) populations characterized by different management regimes

    NARCIS (Netherlands)

    Piotti, A.; Leonardi, S.; Buiteveld, J.; Geburek, T.; Gerber, S.; Kramer, K.; Vettori, C.; Vendramin, G.G.

    2012-01-01

    The study of the dispersal capability of a species can provide essential information for the management and conservation of its genetic variability. Comparison of gene flow rates among populations characterized by different management and evolutionary histories allows one to decipher the role of fac

  15. X-ray beam transfer between hollow fibers for long-distance transport

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Yoshihito, E-mail: tanaka@sci.u-hyogo.ac.jp; Matsushita, Ryuki; Shiraishi, Ryutaro; Hasegawa, Takayuki; Ishikawa, Kiyoshi [Graduate School of Material Science, University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Sayo-gun, Hyogo 678-1297 (Japan); Sawada, Kei; Kohmura, Yoshiki [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Takahashi, Isao [Department of Physics, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337 Japan (Japan)

    2016-07-27

    Fiber optics for controlling the x-ray beam trajectory has been examined at the synchrotron facility of SPring-8. Up to now, we have achieved beam deflection by several tens of milli-radian and axis shift of around 75 mm with a 1.5 m-long flexible hollow glass capillary. The achievable beam deflecting angle, axis shift, and timing delay are, in principle, proportional to the length, the square of length and the cube of length, respectively. Thus, for further applications, requiring larger beam shift and pulse delay, longer fibers are indispensable. In order to achieve long-distance transport using the fiber, we thus examined the connection transferring x-rays between fibers in an experimental hutch. The acceptance angle at the input end and the throughput efficiency of the second fiber is consistent with the consideration of the output beam divergence of the first fiber. The enhancement of the transfer efficiency is also discussed for the cases of a closer joint and the use of a refractive lens as a coupler.

  16. DISTRIBUTED OPTICAL FIBER SENSOR FOR LONG-DISTANCE OIL PIPELINE HEALTH

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A fully distributed optical fiber sensor (DOFS) for monitoring long-distance oil pipeline health is proposed based on optical time domain reflectometry (OTDR). A smart and sensitive optical fiber cable is installed along the pipeline acting as a sensor. The experiments show that the cable swells when exposed to oil and induced additional bending losses inside the fiber, and the optical attenuation of the fiber coated by a thin skin with periodical hardness is sensitive to deformation and vibration caused by oil leakage, tampering,or mechanical impact. The region where the additional attenuation occurred is detected and located by DOFS based on OTDR, the types of pipeline accidents are identified according to the characteristics of transmitted optical power received by an optical power meter. Another prototype of DOFS based on a forward traveling frequency-modulated continuous-wave (FMCW) is also proposed to monitor pipeline. The advantages and disadvantages of DOFSs based on OTDR and FMCW are discussed. The experiments show that DOFSs are capable of detecting and locating distant oil pipeline leakages and damages in real time with an estimated precision of ten meters over tens of kilometers.

  17. Long-distance quantum teleportation assisted with free-space entanglement distribution

    Institute of Scientific and Technical Information of China (English)

    Ren Ji-Gang; Yang Bin; Yi Zhen-Huan; Zhou Fei; Chen Kai; Peng Cheng-Zhi; Pan Jian-Wei

    2009-01-01

    Faithful long-distance quantum teleportation necessitates prior entanglement distribution between two communicated locations.The particle carrying on the unknown quantum information is then combined with one particle of the entangled states for Bell-state measurements,which leads to a transfer of the original quantum information onto the other particle of the entangled states.However in most of the implemented teleportation experiments nowadays,the Bell-state measurements are performed even before successful distribution of entanglement.This leads to an instant collapse of the quantum state for the transmitted particle,which is actually a single-particle transmission thereafter.Thus the true distance for quantum teleportation is,in fact,only in a level of meters.In the present experiment we design a novel scheme which has overcome this limit by utilizing fiber as quantum memory.A complete quantum teleportation is achieved upon successful entanglement distribution over 967 meters in public free space.Active feed-forward control techniques are developed for real-time transfer of quantum information.The overall experimental fidelities for teleported states are better than 89.6%,which signify high-quality teleportation.

  18. Narratives of Psychosocial Response to Microtrauma Injury among Long-Distance Runners

    Directory of Open Access Journals (Sweden)

    Hayley C. Russell

    2015-07-01

    Full Text Available Athletes with microtrauma or overuse injuries resulting from an accumulation of repeated small forces may differ from athletes with macrotrauma or acute injuries in their psychosocial responses because of the unique challenges presented by these insidious-onset and often chronic injuries. Our purpose was to use narrative inquiry to examine the psychosocial experiences and responses of 10 long-distance runners who had experienced microtrauma injuries. Qualitative data analysis of interview data led to a chronological timeline of the injury experience and an assessment of the meaning attributed to these injury experiences using a variation of Mishler’s core-narrative approach. Participants reported distinct thoughts, feelings, and behaviors during each phase of the injury—pre-injury, injury onset, and outcome. In the pre-injury period, participants indicated specific running-related goals and attributed their injuries to overtraining or a change in training. During the injury onset phase, participants consistently indicated two themes: self-diagnosis and treatment, and not taking time off. Within the outcome phase of injury, participants acknowledged changed training because of the injury, and lessons learned from their injury experiences. The narratives of microtrauma-injured runners revealed psychosocial distress and behavioral tendencies post-injury that have important implications for runners, coaches, and healthcare professionals.

  19. Using task dynamics to quantify the affordances of throwing for long distance and accuracy.

    Science.gov (United States)

    Wilson, Andrew D; Weightman, Andrew; Bingham, Geoffrey P; Zhu, Qin

    2016-07-01

    In 2 experiments, the current study explored how affordances structure throwing for long distance and accuracy. In Experiment 1, 10 expert throwers (from baseball, softball, and cricket) threw regulation tennis balls to hit a vertically oriented 4 ft × 4 ft target placed at each of 9 locations (3 distances × 3 heights). We measured their release parameters (angle, speed, and height) and showed that they scaled their throws in response to changes in the target's location. We then simulated the projectile motion of the ball and identified a continuous subspace of release parameters that produce hits to each target location. Each subspace describes the affordance of our target to be hit by a tennis ball moving in a projectile motion to the relevant location. The simulated affordance spaces showed how the release parameter combinations required for hits changed with changes in the target location. The experts tracked these changes in their performance and were successful in hitting the targets. We next tested unusual (horizontal) targets that generated correspondingly different affordance subspaces to determine whether the experts would track the affordance to generate successful hits. Do the experts perceive the affordance? They do. In Experiment 2, 5 cricketers threw to hit either vertically or horizontally oriented targets and successfully hit both, exhibiting release parameters located within the requisite affordance subspaces. We advocate a task dynamical approach to the study of affordances as properties of objects and events in the context of tasks as the future of research in this area. (PsycINFO Database Record

  20. Social networks improve leaderless group navigation by facilitating long-distance communication

    Directory of Open Access Journals (Sweden)

    Nikolai W. F. BODE, A. Jamie WOOD, Daniel W. FRANKS

    2012-04-01

    Full Text Available Group navigation is of great importance for many animals, such as migrating flocks of birds or shoals of fish. One theory states that group membership can improve navigational accuracy compared to limited or less accurate individual navigational ability in groups without leaders (“Many-wrongs principle”. Here, we simulate leaderless group navigation that includes social connections as preferential interactions between individuals. Our results suggest that underlying social networks can reduce navigational errors of groups and increase group cohesion. We use network summary statistics, in particular network motifs, to study which characteristics of networks lead to these improvements. It is networks in which preferences between individuals are not clustered, but spread evenly across the group that are advantageous in group navigation by effectively enhancing long-distance information exchange within groups. We suggest that our work predicts a base-line for the type of social structure we might expect to find in group-living animals that navigate without leaders [Current Zoology 58 (2: 329-341, 2012].

  1. Resource tracking within and across continents in long-distance bird migrants

    KAUST Repository

    Thorup, Kasper

    2017-01-05

    Migratory birds track seasonal resources across and between continents. We propose a general strategy of tracking the broad seasonal abundance of resources throughout the annual cycle in the longest-distance migrating land birds as an alternative to tracking a certain climatic niche or shorter-term resource surplus occurring, for example, during spring foliation. Whether and how this is possible for complex annual spatiotemporal schedules is not known. New tracking technology enables unprecedented spatial and temporal mapping of long-distance movement of birds. We show that three Palearctic-African species track vegetation greenness throughout their annual cycle, adjusting the timing and direction of migratory movements with seasonal changes in resource availability over Europe and Africa. Common cuckoos maximize the vegetation greenness, whereas red-backed shrikes and thrush nightingales track seasonal surplus in greenness. Our results demonstrate that the longest-distance migrants move between consecutive staging areas even within the wintering region in Africa to match seasonal variation in regional climate. End-of-century climate projections indicate that optimizing greenness would be possible but that vegetation surplus might be more difficult to track in the future.

  2. FLOWERING LOCUS T protein may act as the long-distance florigenic signal in the cucurbits.

    Science.gov (United States)

    Lin, Ming-Kuem; Belanger, Helene; Lee, Young-Jin; Varkonyi-Gasic, Erika; Taoka, Ken-Ichiro; Miura, Eriko; Xoconostle-Cázares, Beatriz; Gendler, Karla; Jorgensen, Richard A; Phinney, Brett; Lough, Tony J; Lucas, William J

    2007-05-01

    Cucurbita moschata, a cucurbit species responsive to inductive short-day (SD) photoperiods, and Zucchini yellow mosaic virus (ZYMV) were used to test whether long-distance movement of FLOWERING LOCUS T (FT) mRNA or FT is required for floral induction. Ectopic expression of FT by ZYMV was highly effective in mediating floral induction of long-day (LD)-treated plants. Moreover, the infection zone of ZYMV was far removed from floral meristems, suggesting that FT transcripts do not function as the florigenic signal in this system. Heterografting demonstrated efficient transmission of a florigenic signal from flowering Cucurbita maxima stocks to LD-grown C. moschata scions. Real-time RT-PCR performed on phloem sap collected from C. maxima stocks detected no FT transcripts, whereas mass spectrometry of phloem sap proteins revealed the presence of Cm-FTL1 and Cm-FTL2. Importantly, studies on LD- and SD-treated C. moschata plants established that Cmo-FTL1 and Cmo-FTL2 are regulated by photoperiod at the level of movement into the phloem and not by transcription. Finally, mass spectrometry of florally induced heterografted C. moschata scions revealed that C. maxima FT, but not FT mRNA, crossed the graft union in the phloem translocation stream. Collectively, these studies are consistent with FT functioning as a component of the florigenic signaling system in the cucurbits.

  3. What drives long-distance dispersal? A test of theoretical predictions.

    Science.gov (United States)

    Lowe, Winsor H

    2009-06-01

    Long-distance dispersal (LDD) may contribute disproportionately to species persistence in fragmented landscapes, non-native invasions, and range shifts in response to climate change. However, direct data on LDD are extremely limited, leaving us with little understanding of why it occurs. I used six years of mark-recapture data on the stream salamander Gyrinophilus porphyriticus to test theoretical predictions of how variation in habitat quality affects LDD. Frequency of LDD was quantified using the kurtosis of yearly movement distributions from recaptured animals in a 1-km headwater stream. Temporal and spatial variation in habitat quality were quantified with spatially explicit data on the body condition and dispersion of individuals throughout the study stream. Using information-theoretic model selection criteria, I found that LDD increased during periods of low average body condition and low spatial variation in body condition. Consistent with basic theory, my results indicate that temporal variation in habitat quality is critical to initiating dispersal, and that LDD increases when animals must move farther to encounter higher-quality habitat. This suggests that information on how habitat quality varies in time and space can be useful for predicting LDD. More broadly, this study highlights the value of direct data on animal movement for testing dispersal theory.

  4. Optimization of special physical fitness of sportswomen - super long distances runners by means of run training

    Directory of Open Access Journals (Sweden)

    Karaulova S.I.

    2016-06-01

    Full Text Available Purpose: improvement of special physical fitness of sportswomen - super long distances runners by means of run training. Material: in the research 6 elite sportswomen of 25-27 years’ age participated. We analyzed documents of training proves planning; analyzed sportswomen’s diaries. Results: three cycle system of annual macro cycle’s construction was put in the base of modern training system for elite marathon sportswomen. We found general and partial volumes of run load of different orientation in annual macro cycle. Optimal duration of maximal load’s segments during anaerobic training was from 30 sec. to 3 minutes. Rest between segments was slow run during 3 - 8 minutes. With it, sportswomen fulfilled repeated run at segments of 15х200 m, 15х400 m, 12х600 m. Conclusions: effectiveness of system of sportswomen’s special physical fitness improvement is determined by rational correlation of differently oriented run means, which were directed at increase of special fitness level in marathon.

  5. Air quality and climate benefits of long-distance electricity transmission in China

    Science.gov (United States)

    Peng, Wei; Yuan, Jiahai; Zhao, Yu; Lin, Meiyun; Zhang, Qiang; Victor, David G.; Mauzerall, Denise L.

    2017-06-01

    China is the world’s top carbon emitter and suffers from severe air pollution. It has recently made commitments to improve air quality and to peak its CO2 emissions by 2030. We examine one strategy that can potentially address both issues—utilizing long-distance electricity transmission to bring renewable power to the polluted eastern provinces. Based on an integrated assessment using state-of-the-science atmospheric modeling and recent epidemiological evidence, we find that transmitting a hybrid of renewable (60%) and coal power (40%) (Hybrid-by-wire) reduces 16% more national air-pollution-associated deaths and decreases three times more carbon emissions than transmitting only coal-based electricity. Moreover, although we find that transmitting coal power (Coal-by-Wire, CbW) is slightly more effective at reducing air pollution impacts than replacing old coal power plants with newer cleaner ones in the east (Coal-by-Rail, CbR) (CbW achieves a 6% greater reduction in national total air-pollution-related mortalities than CbR), both coal scenarios have approximately the same carbon emissions. We thus demonstrate that coordinating transmission planning with renewable energy deployment is critical to maximize both local air quality benefits and global climate benefits.

  6. Serum enzyme activities following long-distance running: comparison between Ethiopian and white athletes.

    Science.gov (United States)

    Eliakim, A; Nemet, D; Shenkman, L

    1995-11-01

    Ethiopian runners are famous for their achievements in long-distance running. The recent immigration of Ethiopians to Israel provided an opportunity to compare some physiological variables between elite Ethiopian and white Israeli runners. Six Ethiopian and five white Israeli runners, aged 20 to 40 years, were studied before and after an 11 km race. Venous blood was sampled from each runner prior to the race, and 1 h, 48 h, and 5 days following the race. The activities of creatine kinase (CK), lactate dehydrogenase (LDH) and aspartate aminotransferase (AST) were measured, and levels of serum electrolytes, urea, creatinine, phosphorus, albumin, cholesterol, and alkaline phosphatase were also determined. CK activity rose 2.6-fold with a peak 5 days after the race. LDH and AST levels rose as well (1.4-1.3-fold, respectively). Significant elevations also occurred in serum phosphorus, uric acid, and creatinine concentrations 1 h after the race. In contrast to previous studies in which higher enzyme activities were reported in blacks, we did not detect any difference in serum enzyme values between black and white runners.

  7. Repeated, long-distance migrations by a philopatric predator targeting highly contrasting ecosystems

    Science.gov (United States)

    Lea, James S. E.; Wetherbee, Bradley M.; Queiroz, Nuno; Burnie, Neil; Aming, Choy; Sousa, Lara L.; Mucientes, Gonzalo R.; Humphries, Nicolas E.; Harvey, Guy M.; Sims, David W.; Shivji, Mahmood S.

    2015-06-01

    Long-distance movements of animals are an important driver of population spatial dynamics and determine the extent of overlap with area-focused human activities, such as fishing. Despite global concerns of declining shark populations, a major limitation in assessments of population trends or spatial management options is the lack of information on their long-term migratory behaviour. For a large marine predator, the tiger shark Galeocerdo cuvier, we show from individuals satellite-tracked for multiple years (up to 1101 days) that adult males undertake annually repeated, round-trip migrations of over 7,500 km in the northwest Atlantic. Notably, these migrations occurred between the highly disparate ecosystems of Caribbean coral reef regions in winter and high latitude oceanic areas in summer, with strong, repeated philopatry to specific overwintering insular habitat. Partial migration also occurred, with smaller, immature individuals displaying reduced migration propensity. Foraging may be a putative motivation for these oceanic migrations, with summer behaviour showing higher path tortuosity at the oceanic range extremes. The predictable migratory patterns and use of highly divergent ecosystems shown by male tiger sharks appear broadly similar to migrations seen in birds, reptiles and mammals, and highlight opportunities for dynamic spatial management and conservation measures of highly mobile sharks.

  8. Very rapid long-distance sea crossing by a migratory bird

    Science.gov (United States)

    Alves, José A.; Dias, Maria P.; Méndez, Verónica; Katrínardóttir, Borgný; Gunnarsson, Tómas G.

    2016-11-01

    Landbirds undertaking within-continent migrations have the possibility to stop en route, but most long-distance migrants must also undertake large non-stop sea crossings, the length of which can vary greatly. For shorebirds migrating from Iceland to West Africa, the shortest route would involve one of the longest continuous sea crossings while alternative, mostly overland, routes are available. Using geolocators to track the migration of Icelandic whimbrels (Numenius phaeopus), we show that they can complete a round-trip of 11,000 km making two non-stop sea crossings and flying at speeds of up to 24 m s‑1 the fastest recorded for shorebirds flying over the ocean. Although wind support could reduce flight energetic costs, whimbrels faced headwinds up to twice their ground speed, indicating that unfavourable and potentially fatal weather conditions are not uncommon. Such apparently high risk migrations might be more common than previously thought, with potential fitness gains outweighing the costs.

  9. A review on some of the problems associated with long-distance journeys.

    Science.gov (United States)

    Reilly, T; Waterhouse, J; Edwards, B

    2008-01-01

    Long-distance travel, for business or pleasure, is becoming increasingly common. Any long journey, whether by plane, road or rail, will be associated with "travel fatigue", the combined effects of a changed routine (particularly sleep loss and altered meals) and the general disruption caused by travel. Planning any trip well in advance will minimise many of these problems, but some factors are less easy to guard against; these include sitting in cramped and uncomfortable conditions and, with flights, the hypoxic environment in the cabin. After arrival at a destination in another country, there can be problems with language, altered food and different customs. If the flight has crossed the equator, then there is also likely to be a change in season and natural lighting, and if the flight has, additionally or alternatively, crossed several time zones, then there will also be the problem of "jet lag", caused by a transient dyssynchrony between the "body clock" and the new local time. The new environment might differ from the place of departure with regard to ambient temperature and humidity, altitude, natural lighting (and hence exposure to ultra-violet radiation) and pollution. In all cases, the traveller needs to be aware of these changes before setting off, so that appropriate preparations (different clothing, for example) can be made.

  10. Satellite tracking reveals long distance coastal travel and homing by translocated estuarine crocodiles, Crocodylus porosus.

    Science.gov (United States)

    Read, Mark A; Grigg, Gordon C; Irwin, Steve R; Shanahan, Danielle; Franklin, Craig E

    2007-09-26

    Crocodilians have a wide distribution, often in remote areas, are cryptic, secretive and are easily disturbed by human presence. Their capacity for large scale movements is poorly known. Here, we report the first study of post-release movement patterns in translocated adult crocodiles, and the first application of satellite telemetry to a crocodilian. Three large male Crocodylus porosus (3.1-4.5 m) were captured in northern Australia and translocated by helicopter for 56, 99 and 411 km of coastline, the last across Cape York Peninsula from the west coast to the east coast. All crocodiles spent time around their release site before returning rapidly and apparently purposefully to their capture locations. The animal that circumnavigated Cape York Peninsula to return to its capture site, travelled more than 400 km in 20 days, which is the longest homeward travel yet reported for a crocodilian. Such impressive homing ability is significant because translocation has sometimes been used to manage potentially dangerous C. porosus close to human settlement. It is clear that large male estuarine crocodiles can exhibit strong site fidelity, have remarkable navigational skills, and may move long distances following a coastline. These long journeys included impressive daily movements of 10-30 km, often consecutively.

  11. Mechanistic analytical models for long-distance seed dispersal by wind.

    Science.gov (United States)

    Katul, G G; Porporato, A; Nathan, R; Siqueira, M; Soons, M B; Poggi, D; Horn, H S; Levin, S A

    2005-09-01

    We introduce an analytical model, the Wald analytical long-distance dispersal (WALD) model, for estimating dispersal kernels of wind-dispersed seeds and their escape probability from the canopy. The model is based on simplifications to well-established three-dimensional Lagrangian stochastic approaches for turbulent scalar transport resulting in a two-parameter Wald (or inverse Gaussian) distribution. Unlike commonly used phenomenological models, WALD's parameters can be estimated from the key factors affecting wind dispersal--wind statistics, seed release height, and seed terminal velocity--determined independently of dispersal data. WALD's asymptotic power-law tail has an exponent of -3/2, a limiting value verified by a meta-analysis for a wide variety of measured dispersal kernels and larger than the exponent of the bivariate Student t-test (2Dt). We tested WALD using three dispersal data sets on forest trees, heathland shrubs, and grassland forbs and compared WALD's performance with that of other analytical mechanistic models (revised versions of the tilted Gaussian Plume model and the advection-diffusion equation), revealing fairest agreement between WALD predictions and measurements. Analytical mechanistic models, such as WALD, combine the advantages of simplicity and mechanistic understanding and are valuable tools for modeling large-scale, long-term plant population dynamics.

  12. Long-distance entanglement of spin qubits via quantum Hall edge states

    Science.gov (United States)

    Yang, Guang; Hsu, Chen-Hsuan; Stano, Peter; Klinovaja, Jelena; Loss, Daniel

    2016-02-01

    The implementation of a functional quantum computer involves entangling and coherent manipulation of a large number of qubits. For qubits based on electron spins confined in quantum dots, which are among the most investigated solid-state qubits at present, architectural challenges are often encountered in the design of quantum circuits attempting to assemble the qubits within the very limited space available. Here, we provide a solution to such challenges based on an approach to realizing entanglement of spin qubits over long distances. We show that long-range Ruderman-Kittel-Kasuya-Yosida interaction of confined electron spins can be established by quantum Hall edge states, leading to an exchange coupling of spin qubits. The coupling is anisotropic and can be either Ising type or XY type, depending on the spin polarization of the edge state. Such a property, combined with the dependence of the electron spin susceptibility on the chirality of the edge state, can be utilized to gain valuable insights into the topological nature of various quantum Hall states.

  13. Evaluation of Advanced TCP Stacks on Fast Long-Distance Production Networks

    Energy Technology Data Exchange (ETDEWEB)

    Bullot, H.

    2004-04-08

    With the growing needs of data intensive science, such as High Energy Physics, and the need to share data between multiple remote computer and data centers worldwide, the necessity for high network performance to replicate large volumes (TBytes) of data between remote sites in Europe, Japan and the U.S. is imperative. Currently, most production bulk-data replication on the network utilizes multiple parallel standard (Reno based) TCP streams. Optimizing the window sizes and number of parallel stream is time consuming, complex, and varies (in some cases hour by hour) depending on network configurations and loads. We therefore evaluated new advanced TCP stacks that do not require multiple parallel streams while giving good performances on high speed long-distance network paths. In this paper, we report measurements made on real production networks with various TCP implementations on paths with different Round Trip Times (RTT) using both optimal and sub-optimal window sizes. We compared the New Reno TCP with the following stacks: HS-TCP, Fast TCP, S-TCP, HSTCP-LP, H-TCP and Bic-TCP. The analysis will compare and report on the stacks in terms of achievable throughput, impact on RTT, intra- and inter-protocol fairness, stability, as well as the impact of reverse traffic. We also report on some tentative results from tests made on unloaded 10 Gbps paths during SuperComputing 2003.

  14. Intrinsic parameterization of a computational optical system for long-distance displacement structural monitoring

    Science.gov (United States)

    Martins, Luís F. Lages; Rebordão, José Manuel N. V.; Ribeiro, Álvaro Silva

    2015-01-01

    We aim at the intrinsic parameterization of a computational optical system applied in long-distance displacement measurement of large-scale structures. In this structural-monitoring scenario, the observation distance established between the digital camera and reference targets, which is composed of the computational optical system, can range from 100 up to 1000 m, requiring the use of long-focal length lenses in order to obtain a suitable sensitivity for the three-dimensional displacement measurement of the observed structure which can be of reduced magnitude. Intrinsic parameterization of long-focal length cameras is an emergent issue since conventional approaches applied for reduced focal length cameras are not suitable mainly due to ill-conditioned matrices in least squares estimation procedures. We describe the intrinsic parameterization of a long-focal length camera (600 mm) by the diffractive optical element method and present the obtained estimates and measurement uncertainties, discussing their contribution for the system's validation by calibration field test and displacement measurement campaigns in a long-span suspension bridge.

  15. Long-distance copropagation of quantum key distribution and terabit classical optical data channels

    Science.gov (United States)

    Wang, Liu-Jun; Zou, Kai-Heng; Sun, Wei; Mao, Yingqiu; Zhu, Yi-Xiao; Yin, Hua-Lei; Chen, Qing; Zhao, Yong; Zhang, Fan; Chen, Teng-Yun; Pan, Jian-Wei

    2017-01-01

    Quantum key distribution (QKD) generates symmetric keys between two remote parties and guarantees the keys are not accessible to any third party. Wavelength-division multiplexing between QKD and classical optical communications by sharing the existing fiber-optics infrastructure is highly desired in order to reduce the cost of QKD applications. However, comparing to the light for classical transmission, quantum signals are very weak and easily affected by impairments from classical light, such as the spontaneous Raman-scattering effect. Here, by selecting an optimal wavelength of quantum signals, we significantly reduce the influence of the Raman-scattering effect. In addition, through coherent optical communication technology, we achieve high-speed classical data transmission with relatively low launch powers, thereby further reducing the impairments from classical light. As a result, we realize the multiplexing and long-distance copropagation of QKD and terabit classical data transmission up to 80 km. The data capacity is two orders of magnitude larger than the existing results. Our demonstration verifies the feasibility of QKD and classical communication to share the resources of backbone fiber links and thus taking the utility of QKD a great step forward.

  16. Endemism and long distance dispersal in the waterfleas of Easter Island.

    Science.gov (United States)

    Damme, Kay Van

    2016-08-22

    Easter Island is known for a depauperate terrestrial and aquatic biota. The discovery of new taxa is unusual, even among the island's micro-invertebrates. A new cladoceran, Ovalona pascua sp. nov. (Crustacea: Cladocera: Anomopoda: Chydoridae), is described from freshwater environments. The chydorid, the only known extant cladoceran on the island, is the dominant aquatic invertebrate in the surface waters. Based on detailed morphological comparison, including a character similarity matrix applied across the species in the genus (12 characters/17 spp), the new taxon is proposed here as an insular endemic with affinities in the East (New World). The revision challenges the theory that invasive zooplankton species were introduced from the subantarctic islands during the 18th century. Human introduction is not the main mechanism through which cladocerans could have arrived on Easter Island. Late Pleistocene - Early Holocene fossils in Cañellas-Boltà et al. (2012) from cores in Rano Raraku Lake are identified here as Daphnia O.F. Müller, 1785 (subgenus Ctenodaphnia Dybowski & Grochowski, 1895). The establishment of Daphnia before human colonization on Easter Island provides strong proof of successful long distance dispersal by ephippia over thousands of kilometers of open sea.

  17. Symplasmic networks in secondary vascular tissues: parenchyma distribution and activity supporting long-distance transport.

    Science.gov (United States)

    Spicer, Rachel

    2014-04-01

    Stems that develop secondary vascular tissue (i.e. xylem and phloem derived from the vascular cambium) have unique demands on transport owing to their mass and longevity. Transport of water and assimilates must occur over long distances, while the increasing physical separation of xylem and phloem requires radial transport. Developing secondary tissue is itself a strong sink positioned between xylem and phloem along the entire length of the stem, and the integrity of these transport tissues must be maintained and protected for years if not decades. Parenchyma cells form an interconnected three-dimensional lattice throughout secondary xylem and phloem and perform critical roles in all of these tasks, yet our understanding of their physiology, the nature of their symplasmic connections, and their activity at the symplast-apoplast interface is very limited. This review highlights key historical work as well as current research on the structure and function of parenchyma in secondary vascular tissue in the hopes of spurring renewed interest in this area, which has important implications for whole-plant transport processes and resource partitioning.

  18. [Intensive care within the context of military long-distance transport].

    Science.gov (United States)

    Hossfeld, B; Rohowsky, B; Rödig, E; Lampl, L

    2004-05-01

    Due to the changed task spectrum of the German Federal Armed Forces with participation in international deployments for UN and NATO the concept of Aeromedical Evacuation (MedEvac) gained a new quality for the Air Force as well as for the Medical Corps. The transport of mostly severely injured or critically ill patients requires both, medical equipment which has to be permanently adapted to the national standard, and qualified intensive-care-personnel. At present, the aircrafts used for such deployments are four C-160 Transall, one CL-601 Challenger and two Airbus A310, which, if necessary, can be equipped with one or more intensive-care "patient transportation units" (PTU). Contrary to the two other aircrafts, the CL-601 Challenger is only equipped for the intensive-care transport of one individual patient. The PTU corresponds to the technical equipment of the intensive care unit of a level-1-trauma centre and ensures an intensive-care therapy on highest level also during longer transportation. The work with this equipment, the characteristics of the long-distance air transport and the special situation of the military deployment causes special demands on the qualifications of the assigned personnel. Primarily planned for the repatriation of injured or ill soldiers, in the mean time, this concept is also essential for the medevac of civilian victims after mass casualties worldwide.

  19. Simulating Long Distance Seed Dispersal for Trees under Rapid Climate Change

    Science.gov (United States)

    Snell, R. S.; Cowling, S. A.

    2011-12-01

    Future climate change scenarios predict a rapid shift in the size and location of suitable habitat for many tree species. The need for human assisted seed dispersal assumes that trees won't arrive at these new habitats by themselves. Some species won't be able to migrate fast enough to track climate change (i.e. estimated rates of 1000m/year or more), whereas other species may find moving through a fragmented landscape an additional challenge. It is important to identify the species which are most likely to require human assistance, however our current suite of vegetation-climate simulation models include unrealistic representations of seed dispersal. Vegetation climate models assume either no dispersal or perfect dispersal (where seeds can arrive at any destination regardless of barriers or absolute distance). For most tree species, seed dispersal lies somewhere between these two extremes. We will present the first time seed dispersal has been explicitly incorporated into a mechanistic vegetation-climate model (LPJ-GUESS). The model was parameterized using published seed dispersal kernels for various tree species in Eastern North America. Due to the large scale of the simulated area, only long distance dispersal events were included. However, these rare dispersal events were sufficient to simulate vegetation migration across a landscape. This model will improve our ability to predict which trees are likely to migrate fast enough under rapid climate change and those which are likely to need assistance.

  20. Social networks improve leaderless group navigation by facilitating long-distance communication

    Institute of Scientific and Technical Information of China (English)

    Nikolai W.F.BODE; A.Jamie WOOD; Daniel W.FRANKS

    2012-01-01

    Group navigation is of great importance for many animals,such as migrating flocks of birds or shoals of fish.One theory states that group membership can improve navigational accuracy compared to limited or less accurate individual navigational ability in groups without leaders ("Many-wrongs principle").Here,we simulate leaderless group navigation that includes social connectious as preferential interactions between individuals.Our results suggest that underlying social networks can reduce navigational errors of groups and increase group cohesion.We use network summary statistics,in particular network motifs,to study which characteristics of networks lead to these improvements.It is networks in which preferences between individuals are not clustered,but spread evenly across the group that are advantageous in group navigation by effectively enhancing long-distance information exchange within groups.We suggest that our work predicts a base-line for the type of social structure we might expect to find in group-living animals that navigate without leaders [Current Zoology 58 (2):329-341,2012].

  1. Satellite tracking reveals long distance coastal travel and homing by translocated estuarine crocodiles, Crocodylus porosus.

    Directory of Open Access Journals (Sweden)

    Mark A Read

    Full Text Available Crocodilians have a wide distribution, often in remote areas, are cryptic, secretive and are easily disturbed by human presence. Their capacity for large scale movements is poorly known. Here, we report the first study of post-release movement patterns in translocated adult crocodiles, and the first application of satellite telemetry to a crocodilian. Three large male Crocodylus porosus (3.1-4.5 m were captured in northern Australia and translocated by helicopter for 56, 99 and 411 km of coastline, the last across Cape York Peninsula from the west coast to the east coast. All crocodiles spent time around their release site before returning rapidly and apparently purposefully to their capture locations. The animal that circumnavigated Cape York Peninsula to return to its capture site, travelled more than 400 km in 20 days, which is the longest homeward travel yet reported for a crocodilian. Such impressive homing ability is significant because translocation has sometimes been used to manage potentially dangerous C. porosus close to human settlement. It is clear that large male estuarine crocodiles can exhibit strong site fidelity, have remarkable navigational skills, and may move long distances following a coastline. These long journeys included impressive daily movements of 10-30 km, often consecutively.

  2. Long-distance electron transfer by cable bacteria in aquifer sediments.

    Science.gov (United States)

    Müller, Hubert; Bosch, Julian; Griebler, Christian; Damgaard, Lars Riis; Nielsen, Lars Peter; Lueders, Tillmann; Meckenstock, Rainer U

    2016-08-01

    The biodegradation of organic pollutants in aquifers is often restricted to the fringes of contaminant plumes where steep countergradients of electron donors and acceptors are separated by limited dispersive mixing. However, long-distance electron transfer (LDET) by filamentous 'cable bacteria' has recently been discovered in marine sediments to couple spatially separated redox half reactions over centimeter scales. Here we provide primary evidence that such sulfur-oxidizing cable bacteria can also be found at oxic-anoxic interfaces in aquifer sediments, where they provide a means for the direct recycling of sulfate by electron transfer over 1-2-cm distance. Sediments were taken from a hydrocarbon-contaminated aquifer, amended with iron sulfide and saturated with water, leaving the sediment surface exposed to air. Steep geochemical gradients developed in the upper 3 cm, showing a spatial separation of oxygen and sulfide by 9 mm together with a pH profile characteristic for sulfur oxidation by LDET. Bacterial filaments, which were highly abundant in the suboxic zone, were identified by sequencing of 16S rRNA genes and fluorescence in situ hybridization (FISH) as cable bacteria belonging to the Desulfobulbaceae. The detection of similar Desulfobulbaceae at the oxic-anoxic interface of fresh sediment cores taken at a contaminated aquifer suggests that LDET may indeed be active at the capillary fringe in situ.

  3. Long-distance delivery of bacterial virulence factors by Pseudomonas aeruginosa outer membrane vesicles.

    Directory of Open Access Journals (Sweden)

    Jennifer M Bomberger

    2009-04-01

    Full Text Available Bacteria use a variety of secreted virulence factors to manipulate host cells, thereby causing significant morbidity and mortality. We report a mechanism for the long-distance delivery of multiple bacterial virulence factors, simultaneously and directly into the host cell cytoplasm, thus obviating the need for direct interaction of the pathogen with the host cell to cause cytotoxicity. We show that outer membrane-derived vesicles (OMV secreted by the opportunistic human pathogen Pseudomonas aeruginosa deliver multiple virulence factors, including beta-lactamase, alkaline phosphatase, hemolytic phospholipase C, and Cif, directly into the host cytoplasm via fusion of OMV with lipid rafts in the host plasma membrane. These virulence factors enter the cytoplasm of the host cell via N-WASP-mediated actin trafficking, where they rapidly distribute to specific subcellular locations to affect host cell biology. We propose that secreted virulence factors are not released individually as naked proteins into the surrounding milieu where they may randomly contact the surface of the host cell, but instead bacterial derived OMV deliver multiple virulence factors simultaneously and directly into the host cell cytoplasm in a coordinated manner.

  4. Nonoptimal component placement, but short processing paths, due to long-distance projections in neural systems.

    Directory of Open Access Journals (Sweden)

    Marcus Kaiser

    2006-07-01

    Full Text Available It has been suggested that neural systems across several scales of organization show optimal component placement, in which any spatial rearrangement of the components would lead to an increase of total wiring. Using extensive connectivity datasets for diverse neural networks combined with spatial coordinates for network nodes, we applied an optimization algorithm to the network layouts, in order to search for wire-saving component rearrangements. We found that optimized component rearrangements could substantially reduce total wiring length in all tested neural networks. Specifically, total wiring among 95 primate (Macaque cortical areas could be decreased by 32%, and wiring of neuronal networks in the nematode Caenorhabditis elegans could be reduced by 48% on the global level, and by 49% for neurons within frontal ganglia. Wiring length reductions were possible due to the existence of long-distance projections in neural networks. We explored the role of these projections by comparing the original networks with minimally rewired networks of the same size, which possessed only the shortest possible connections. In the minimally rewired networks, the number of processing steps along the shortest paths between components was significantly increased compared to the original networks. Additional benchmark comparisons also indicated that neural networks are more similar to network layouts that minimize the length of processing paths, rather than wiring length. These findings suggest that neural systems are not exclusively optimized for minimal global wiring, but for a variety of factors including the minimization of processing steps.

  5. Fat-tailed gene flow in the dioecious canopy tree species Fraxinus mandshurica var. japonica revealed by microsatellites.

    Science.gov (United States)

    Goto, S; Shimatani, K; Yoshimaru, H; Takahashi, Y

    2006-09-01

    Pollen flow, seed dispersal and individual reproductive success can be simultaneously estimated from the genotypes of adults and offspring using stochastic models. Using four polymorphic microsatellite loci, gene flow of the wind-pollinated and wind-seed-dispersed dioecious tree species, Fraxinus mandshurica var. japonica, was quantified in a riparian forest, in northern Japan. In a 10.5-ha plot, 74 female adults, 76 male adults and 292 current-year seedlings were mapped and genotyped, together with 200 seeds. To estimate dispersal kernels of pollen and seeds, we applied normal, exponential power, Weibull, bivariate t-distribution kernels, and two-component models consisting of two normal distribution functions, one with a small and one with a large variance. A two-component pollen flow model with a small contribution (26.1%) from short-distance dispersal (sigma = 7.2 m), and the rest from long-distance flow (sigma = 209.9 m), was chosen for the best-fitting model. The average distance that integrated pollen flows inside and outside the study plot was estimated to be 196.8 m. Tree size and flowering intensity affected reproduction, and there appeared to be critical values that distinguished reproductively successful and unsuccessful adults. In contrast, the gene flow model that estimated both pollen and seed dispersal from established seedlings resulted in extensive seed dispersal, and the expected spatial genetic structures did not satisfactorily fit with the observations, even for the selected model. Our results advanced small-scale individual-based parentage analysis for quantifying fat-tailed gene flow in wind-mediated species, but also clarified its limitations and suggested future possibilities for gene flow studies.

  6. Horse chestnut pollen quality

    Directory of Open Access Journals (Sweden)

    Ćalić Dušica

    2017-01-01

    Full Text Available Pollen quality of horse chestnut, expressed as pollen productivity, viability and germination was studied. Anthers of horse chestnut genotypes had pollen production from 3.66 to 5.06 x 103 pollen grains per anther, depending of genotype. Also, pollen of horse chestnut Ah1-Ah4 genotypes showed different viability (from 56 to 68%, after staining with fluorescein diacetate. Pollen germination of Ah1-Ah4 genotypes varied from 50-66% on basic medium. Inclusion of polyethylene glycol-PEG from 10%, 15% and 20% v/w increased pollen germination. The best results were achieved on medium with the largest PEG concentration. On these medium 76-91% pollen grains were germinated, depending of genotype. The best pollen quality, for all tested parameters, had genotype Ah2. Knowledge about morphology, production, viability, in vitro germination, tube growth as well as pollen: ovule ratio can be of great importance for future pollen biology studies. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 173015

  7. Pollen, water, and wind: Chaotic mixing in a puddle of water

    DEFF Research Database (Denmark)

    Jensen, Kaare Hartvig

    2016-01-01

    This paper talks about how pine pollen grains dispersedin an approximately 1 m wide and 1 cm deep water puddle. The pollen has mixed due to wind blowing across the liquid surface, revealing a strikingly complex flow pattern. The flows revealed by nature’s tracer particles may influence circulatio......, and typically measures ∼50 μm in diameter. Pollen is transferred from a pollen cone to the ovule by wind or insects, and produces male sperm cells...

  8. Phloem Proteomics Reveals New Aspects of Long-distance Signaling in Plants

    Institute of Scientific and Technical Information of China (English)

    Urs F.Benning; Banita Tamot; Susanne Hoffmann-Benning

    2012-01-01

    As the world population grows our need for food and fuel increases drastically.Given the additional impact of the global climate change a second "green revolution",however seems unlikely to be achieved by simply adding fertilizer or accessing new land but will need a better understanding of the factors and processes essential for plant growth and development.One of those processes is the adaptation of plants to their environment.Since plants are sessile and cannot move to appropriate hiding places or feeding grounds to escape adverse conditions,they evolved mechanisms to detect changes in their environment,communicate these to different organs,and adjust development accordingly.One of these adaptations,the phloem,serves as a major trafficking pathway for assimilates,viruses,RNA,plant hormones,metabolites,and proteins with functions ranging from synthesis to metabolism to signaling.The study of signaling compounds within the phloem is essential for our understanding of plant communication of environmental cues.Determining the nature of signals and the mechanisms by which they are communicated through the phloem will lead to a more complete understanding of plant development and plant responses to stress and,as a result could lead to the development of plants with increased adaptation to a changed environment.Our analysis of Arabidopsis phloem exudates revealed several lipid-binding proteins as well as lipids.Lipids are not typically expected in the aqueous environment of SEs.Yet the long-distance transport of hydrophobic compounds in aqueous systems is not without precedence in biological systems:In human blood lipids are often bound to proteins and transported for storage,use,modification,or degradation; alternatively,they serve as messengers and modulate transcription factor activity and,as a result,development.It is conceivable that lipids and the respective lipid-binding proteins in the phloem serve similar functions in plants and play an important role in

  9. Meanings and vulnerability to HIV/AIDS among long-distance truck drivers in Brazil.

    Science.gov (United States)

    Magno, Laio; Castellanos, Marcelo Eduardo Pfeiffer

    2016-12-22

    To understand the meanings assigned by long-distance truck drivers to HIV/AIDS and its transmission and prevention, bearing in mind different contexts of vulnerability. Qualitative research with 22 truck drivers. Semi-structured interviews and participant observation were conducted in highways of the state of Bahia in 2013. We selected male truck drivers, with one year or more of work experience in long-distance routes. We carried out the thematic analysis of the interviews, to identify different contexts of vulnerability. The results showed that the insertion of truck drivers in contexts of high social vulnerability (poor working conditions, violence on the roads, and use of alcohol and other drugs) along with the advances in access and effectiveness of treatment for AIDS promote a reduced perception of the risk and severity of this disease. In addition, the notion of "risk group" and the symbolic division between "home space" (protected) and "street space" (unprotected) intensified a restricted and specific use of condoms, guided by the opposition between "woman of the street" (unknown women, prostitutes, among others) and "woman of the house" (wives, girlfriends). The meanings assigned by truckers to AIDS incorporated elements of recent transformations of the expanded social context, such as the development of health technologies (especially anti-retroviral drugs) and the guarantee of free access to treatment in the Brazilian public health system; but also incorporated old elements of social vulnerability context - such as the poor working conditions on Brazilian highways. Compreender os significados atribuídos pelos caminhoneiros de rota longa ao HIV/aids e à sua transmissão e prevenção, tendo em vista diferentes contextos de vulnerabilidade. Pesquisa qualitativa com 22 caminhoneiros. Foram realizadas entrevistas semi-estruturadas e observação participante em rodovias do estado da Bahia em 2013. Foram selecionados caminhoneiros do sexo masculino, com um

  10. Transport of airborne Picea schrenkiana pollen on the northern slope of Tianshan Mountains (Xinjiang, China) and its implication for paleoenvironmental reconstruction.

    Science.gov (United States)

    Pan, Yanfang; Yan, Shun; Behling, Hermann; Mu, Guijin

    2013-06-01

    The understanding of airborne pollen transportation is crucial for the reconstruction of the paleoenvironment. Under favorable conditions, a considerable amount of long-distance-transported pollen can be deposited far from its place of origin. In extreme arid regions, in most cases, such situations occur and increase the difficulty to interpret fossil pollen records. In this study, three sets of Cour airborne pollen trap were installed on the northern slope of Tianshan Mountains to collect airborne Picea schrenkiana (spruce) pollen grains from July 2001 to July 2006. The results indicate that Picea pollen disperses extensively and transports widely in the lower atmosphere far away from spruce forest. The airborne Picea pollen dispersal period is mainly concentrated between mid-May and July. In desert area, weekly Picea pollen began to increase and peaked suddenly in concentration. Also, annual pollen indices do not decline even when the distance increased was probably related to the strong wind may pick up the deposited pollen grains from the topsoil into the air stream, leading to an increase of pollen concentration in the air that is irrelevant to the normal and natural course of pollen transport and deposition. This, in turn, may lead to erroneous interpretations of the pollen data in the arid region. This study provided insight into the shift in the Picea pollen season regarding climate change in arid areas. It is recorded that the pollen pollination period starts earlier and the duration became longer. The results also showed that the temperature of May and June was positively correlated with the Picea pollen production. Furthermore, the transport of airborne Picea pollen data is useful for interpreting fossil pollen records from extreme arid regions.

  11. Innovation design of long-distance pipelines buried under high-filling planned roads

    Directory of Open Access Journals (Sweden)

    Xueshen Zhou

    2015-03-01

    Full Text Available If a long-distance gas pipeline is unavoidably buried under a planned high-filling road, the high fill subgrade setting will result in the change of the pipe's mechanical shape and the local stress concentration on the pipe, which will pose threats to the safe operation of the pipeline. Protection culverts are generally adopted to solve this issue, but the construction of protection culverts are difficult and high in cost and usually unable to meet the requirements of construction schedule of the planned road project by the local government. For this reason, the stress on pipelines in high fill subgrade was analyzed and a rectification measure was proposed and its safety and rationality was also calculated. The results show that increasing pipe thickness is a feasible rectification measure. Thus, we analyzed the stability of and stress on the pipe caused by the uneven high fill setting by using the ABAQUS finite element software package, in which the pipe was simulated as the beam element, the backfill above the pipe as the stress load, and the elastic foundation underneath the pipe as the evenly-distributed spring. From the stress cloud charts, we can see the stress concentration on the pipe where a sudden change occurs in high fill setting. Without proper measures, accidents would be inevitable in the end. The analysis results from the ABAQUS also show that the scheme of increasing the pipe thickness will be the most cost-effective and practical way to deal with the stress resulted from the uneven high fill setting above the pipe. But it is pointed out that the pipeline laying route should avoid planned high filling roads as far as possible to ensure its safe operation.

  12. Waterfowl endozoochory: An overlooked long-distance dispersal mode for Cuscuta (dodder)

    Science.gov (United States)

    Costea, Mihai; Stefanović, Saša; García, Miguel A.; De La Cruz, Susan; Casazza, Michael L.; Green, Andy J.

    2016-01-01

    REMISE OF THE STUDY: Dispersal of parasitic Cuscuta species (dodders) worldwide has been assumed to be largely anthropomorphic because their seeds do not match any previously known dispersal syndrome and no natural dispersal vectors have been reliably documented. However, the genus has a subcosmopolitan distribution and recent phylogeographic results have indicated that at least18 historical cases of long-distance dispersal (LDD) have occurred during its evolution. The objective of this study is to report the first LDD biological vector for Cuscuta seeds. METHODS: Twelve northern pintails (Anas acuta) were collected from Suisun Marsh, California and the contents of their lowest part of the large intestine (rectum) were extracted and analyzed. Seed identification was done both morphologically and using a molecular approach. Extracted seeds were tested for germination and compared to seeds not subjected to gut passage to determine the extent of structural changes caused to the seed coat by passing through the digestive tract. KEY RESULTS: Four hundred and twenty dodder seeds were found in the rectum of four northern pintails. From these, 411 seeds were identified as Cuscuta campestris and nine as most likely C. pacifica. The germination rate of C. campestris seeds after gut passage was 55%. Structural changes caused by the gut passage in both species were similar to those caused by an acid scarification. CONCLUSIONS: Endozoochory by waterbirds may explain the historical LDD cases in the evolution of Cuscuta. This also suggests that current border quarantine measures may be insufficient to stopping spreading of dodder pests along migratory flyways.

  13. Weather conditions promote route flexibility during open ocean crossing in a long-distance migratory raptor

    Science.gov (United States)

    Mellone, Ugo; López-López, Pascual; Limiñana, Rubén; Urios, Vicente

    2011-07-01

    Weather conditions are paramount in shaping birds' migratory routes, promoting the evolution of behavioural plasticity and allowing for adaptive decisions on when to depart or stop during migration. Here, we describe and analyze the influence of weather conditions in shaping the sea-crossing stage of the pre-breeding journey made by a long-distance migratory bird, the Eleonora's falcon ( Falco eleonorae), tracked by satellite telemetry from the wintering grounds in the Southern Hemisphere to the breeding sites in the Northern Hemisphere. As far as we know, the data presented here are the first report of repeated oceanic journeys of the same individuals in consecutive years. Our results show inter-annual variability in the routes followed by Eleonora's falcons when crossing the Strait of Mozambique, between Madagascar and eastern continental Africa. Interestingly, our observations illustrate that individuals show high behavioural plasticity and are able to change their migration route from one year to another in response to weather conditions, thus minimising the risk of long ocean crossing by selecting winds blowing towards Africa for departure and changing the routes to avoid low pressure areas en route. Our results suggest that weather conditions can really act as obstacles during migration, and thus, besides ecological barriers, the migratory behaviour of birds could also be shaped by "meteorological barriers". We briefly discuss orientation mechanisms used for navigation. Since environmental conditions during migration could cause carry-over effects, we consider that forecasting how global changes of weather patterns will shape the behaviour of migratory birds is of the utmost importance.

  14. El Nino-Southern Oscillation is linked to decreased energetic condition in long-distance migrants.

    Directory of Open Access Journals (Sweden)

    Kristina L Paxton

    Full Text Available Predicting how migratory animals respond to changing climatic conditions requires knowledge of how climatic events affect each phase of the annual cycle and how those effects carry-over to subsequent phases. We utilized a 17-year migration dataset to examine how El Niño-Southern Oscillation climatic events in geographically different regions of the Western hemisphere carry-over to impact the stopover biology of several intercontinental migratory bird species. We found that migratory birds that over-wintered in South America experienced significantly drier environments during El Niño years, as reflected by reduced Normalized Difference Vegetation Index (NDVI values, and arrived at stopover sites in reduced energetic condition during spring migration. During El Niño years migrants were also more likely to stopover immediately along the northern Gulf coast of the southeastern U.S. after crossing the Gulf of Mexico in small suboptimal forest patches where food resources are lower and migrant density often greater than larger more contiguous forests further inland. In contrast, NDVI values did not differ between El Niño and La Niña years in Caribbean-Central America, and we found no difference in energetic condition or use of coastal habitats for migrants en route from Caribbean-Central America wintering areas. Birds over-wintering in both regions had consistent median arrival dates along the northern Gulf coast, suggesting that there is a strong drive for birds to maintain their time program regardless of their overall condition. We provide strong evidence that not only is the stopover biology of migratory landbirds influenced by events during the previous phase of their life-cycle, but where migratory birds over-winter determines how vulnerable they are to global climatic cycles. Increased frequency and intensity of ENSO events over the coming decades, as predicted by climatic models, may disproportionately influence long-distance migrants

  15. Beyond species recognition: somatic state affects long-distance sex pheromone communication.

    Science.gov (United States)

    Chemnitz, Johanna; Jentschke, Petra C; Ayasse, Manfred; Steiger, Sandra

    2015-08-07

    Long-range sex pheromones have been subjected to substantial research with a particular focus on their biosynthesis, peripheral perception, central processing and the resulting orientation behaviour of perceivers. Fundamental to the research on sex attractants was the assumption that they primarily coordinate species recognition. However, especially when they are produced by the less limiting sex (usually males), the evolution of heightened condition dependence might be expected and long-range sex pheromones might, therefore, also inform about a signaller's quality. Here we provide, to our knowledge, the first comprehensive study of the role of a male's long-range pheromone in mate choice that combines chemical analyses, video observations and field experiments with a multifactorial manipulation of males' condition. We show that the emission of the long-distance sex pheromone of the burying beetle, Nicrophorus vespilloides is highly condition-dependent and reliably reflects nutritional state, age, body size and parasite load--key components of an individual's somatic state. Both, the quantity and ratio of the pheromone components were affected but the time invested in pheromone emission was largely unaffected by a male's condition. Moreover, the variation in pheromone emission caused by the variation in condition had a strong effect on the attractiveness of males in the field, with males in better nutritional condition, of older age, larger body size and bearing less parasites being more attractive. That a single pheromone is influenced by so many aspects of the somatic state and causes such variation in a male's attractiveness under field conditions was hitherto unknown and highlights the need to integrate indicator models of sexual selection into pheromone research.

  16. Airborne multi-axis DOAS measurements of atmospheric trace gases on CARIBIC long-distance flights

    Directory of Open Access Journals (Sweden)

    B. Dix

    2009-11-01

    Full Text Available A DOAS (Differential Optical Absorption Spectroscopy instrument was implemented and operated onboard a long-distance passenger aircraft within the framework of the CARIBIC project (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container. The instrument was designed to keep weight, size and power consumption low and to comply with civil aviation regulations. It records spectra of scattered light from three viewing directions (nadir, 10° above and below horizon using a miniaturized telescope system. The telescopes are integrated in the main pylon of the inlet system which is mounted at the belly of the aircraft. Fibre bundles transmit light from the telescopes to spectrograph-detector units inside the DOAS container instrument. The latter is part of the removable CARIBIC instrument container, which is installed monthly on the aircraft for a series of measurement flights.

    During 30 flight operations within three years, measurements of HCHO, HONO, NO2, BrO, O3 and the oxygen dimer O4 were conducted. All of these trace gases except BrO could be analysed with a 30 s time resolution. HONO was detected for the first time in a deep convective cloud over central Asia, while BrO, NO2 and O3 could be observed in tropopause fold regions. Biomass burning signatures over South America could be seen and measurements during ascent and descent provided information on boundary layer trace gas profiles (e.g. NO2 or HCHO.

  17. Long-Distance Dispersal Shaped Patterns of Human Genetic Diversity in Eurasia.

    Science.gov (United States)

    Alves, Isabel; Arenas, Miguel; Currat, Mathias; Sramkova Hanulova, Anna; Sousa, Vitor C; Ray, Nicolas; Excoffier, Laurent

    2016-04-01

    Most previous attempts at reconstructing the past history of human populations did not explicitly take geography into account or considered very simple scenarios of migration and ignored environmental information. However, it is likely that the last glacial maximum (LGM) affected the demography and the range of many species, including our own. Moreover, long-distance dispersal (LDD) may have been an important component of human migrations, allowing fast colonization of new territories and preserving high levels of genetic diversity. Here, we use a high-quality microsatellite data set genotyped in 22 populations to estimate the posterior probabilities of several scenarios for the settlement of the Old World by modern humans. We considered models ranging from a simple spatial expansion to others including LDD and a LGM-induced range contraction, as well as Neolithic demographic expansions. We find that scenarios with LDD are much better supported by data than models without LDD. Nevertheless, we show evidence that LDD events to empty habitats were strongly prevented during the settlement of Eurasia. This unexpected absence of LDD ahead of the colonization wave front could have been caused by an Allee effect, either due to intrinsic causes such as an inbreeding depression built during the expansion or due to extrinsic causes such as direct competition with archaic humans. Overall, our results suggest only a relatively limited effect of the LGM contraction on current patterns of human diversity. This is in clear contrast with the major role of LDD migrations, which have potentially contributed to the intermingled genetic structure of Eurasian populations. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  18. Recent long-distance dispersal overshadows ancient biogeographical patterns in a pantropical angiosperm family (Simaroubaceae, Sapindales).

    Science.gov (United States)

    Clayton, Joshua W; Soltis, Pamela S; Soltis, Douglas E

    2009-08-01

    Detailed biogeographic studies of pantropical clades are still relatively few, and those conducted to date typically use parsimony or event-based methods to reconstruct ancestral areas. In this study, a recently developed likelihood method for reconstructing ancestral areas (the dispersal-extinction cladogenesis [DEC] model) is applied to the angiosperm family Simaroubaceae, a geographically widespread and ecologically diverse clade of pantropical and temperate trees and shrubs. To estimate divergence dates in the family, Bayesian uncorrelated rates analyses and robust fossil calibrations are applied to the well-sampled and strongly supported phylogeny. For biogeographic analyses, the effects of parameter configurations in the DEC model are assessed for different possible ancestral ranges, and the likelihood method is compared with dispersal-vicariance analysis (DIVA). Regardless of the parameters used, likelihood analyses show a common pattern of multiple recent range shifts that overshadow reconstruction of events deeper in the family's history. DIVA produced results similar to the DEC model when ancestral ranges were restricted to two areas, but some improbable ancestral ranges were also observed. Simaroubaceae exhibit an early history of range expansion between major continental areas in the Northern Hemisphere, but reconstruction of ancestral areas for lineages diverging in the early Tertiary are sensitive to the parameters of the model used. A North American origin is suggested for the family, with migration via Beringia by ancestral taxa. In contrast to traditional views, long-distance dispersal events are common, particularly in the Late Oligocene and later. Notable dispersals are inferred to have occurred across the Atlantic Ocean in both directions, as well as between Africa and Asia, and around the Indian Ocean basin and Pacific islands.

  19. Short communication: Microbial quality of raw milk following commercial long-distance hauling.

    Science.gov (United States)

    Darchuk, Emily M; Meunier-Goddik, Lisbeth; Waite-Cusic, Joy

    2015-12-01

    Hauling is a critical part of the commercial milk supply chain, yet very few studies have aimed to understand its effect on raw milk quality. This study focused on the effect of extended-duration tanker use during hauling on raw milk quality at a commercial facility. Standard tanker use [cleaned-in-place (CIP) once per 24h] served as a control and an incremental between-load water rinse with sanitizer treatment (RS) was evaluated to mitigate any effect from extended duration hauling. During this study, 1 commercial truck with 2 trailers was monitored for 10d. The truck collected milk at a large dairy farm, transported the milk to a manufacturing facility, and then returned to the same farm for a second load. Each round-trip journey took between 10 and 12h, allowing for 2 loads per 24-h use period. Following the second delivery, the truck was cleaned by CIP treatment starting a new treatment day. Producer samples were collected from the raw milk bulk tank on the farm before loading milk into the tanker. The same milk was sampled directly out of the tanker truck before unloading at the manufacturer. Effect on individual bacteria count, thermophilic spore count, and preliminary incubation count was quantified through common industry tests. Surface sponge swabs were also used to monitor tanker sanitation and the efficacy of cleaning treatments. Results did not identify a negative effect on raw milk quality due to extended duration hauling. Whereas the addition of RS did not provide any measurable quality benefits for the microbial milk quality, swab results demonstrated that the RS treatment was able to reduce surface bacteria in the tanker, although not to the same level as the full CIP treatment. Based on this study, current CIP practices for long distance milk hauling appear to be effective in mitigating any measurable effect on raw milk quality.

  20. Rapid rehabilitation programme following sacral stress fracture in a long-distance running female athlete.

    Science.gov (United States)

    Knobloch, Karsten; Schreibmueller, Louisa; Jagodzinski, Michael; Zeichen, Johannes; Krettek, Christian

    2007-11-01

    Stress fractures occur in normal bone due to mechanical overload by cyclic stress increasing the osteoclastic activity, thus facilitating weakening leading to fracture of bones. Long-distance running may lead to stress fractures of the mid- and distal tibia and of the metatarsal bones. Stress fractures to the sacrum are rare. Certain factors for stress fractures in runners have been identified, such as leg-length inequality, a high longitudinal arch of the foot, forefoot varus, and menstrual irregularities in case of female athlete triad. We report on a 22-year-old female runner (usually training 140 km/week) suffering a sacral fatigue-type fracture. The female athlete triad with eating disorders, dysmenorrhea, and osteopenia was ruled out. Sexual hormone blood samples proofed normal values. The diagnosis was performed using magnetic resonance imaging 2 weeks after the onset of buttock pain. A conservative treatment regimen was initiated with strict physical rest for the first 2 weeks, and then gradual increase of physical activity with 60-90 min of daily cycling and moderate 2 x 60 min cross-training. After another 2 weeks time, daily 60-90 min of walking, Nordic pole walking, and moderate strength training two times a week was performed. At 7 weeks running was started, gradually increased to 90 km/week without any pain. A rapid rehabilitation programme after sacral stress fractures involving low impact physical activity, such as Walking and Nordic pole walking, is applicable to female athletes after ruling out the female athlete triad.

  1. Climatic conditions produce contrasting influences on demographic traits in a long-distance Arctic migrant.

    Science.gov (United States)

    Cleasby, Ian R; Bodey, Thomas W; Vigfusdottir, Freydis; McDonald, Jenni L; McElwaine, Graham; Mackie, Kerry; Colhoun, Kendrew; Bearhop, Stuart

    2017-03-01

    The manner in which patterns of variation and interactions among demographic rates contribute to population growth rate (λ) is key to understanding how animal populations will respond to changing climatic conditions. Migratory species are likely to be particularly sensitive to climatic conditions as they experience a range of different environments throughout their annual cycle. However, few studies have provided fully integrated demographic analyses of migratory populations in response to changing climatic conditions. Here, we employed integrated population models to demonstrate that the environmental conditions experienced during a short but critical period play a central role in the demography of a long-distance migrant, the light-bellied Brent goose (Branta bernicla hrota). Female survival was positively associated with June North Atlantic Oscillation (NAO) values, whereas male survival was not. In contrast, breeding productivity was negatively associated with June NAO, suggesting a trade-off between female survival and reproductive success. Both adult female and adult male survival showed low temporal variation, whereas there was high temporal variation in recruitment and breeding productivity. In addition, while annual population growth was positively correlated with annual breeding productivity, a sensitivity analysis revealed that population growth was most sensitive to changes in adult survival. Our results demonstrate that the environmental conditions experienced during a relatively short-time window at the start of the breeding season play a critical role in shaping the demography of a long-distant Arctic migrant. Crucially, different demographic rates responded in opposing directions to climatic variation, emphasising the need for integrated analysis of multiple demographic traits when understanding population dynamics. © 2016 The Authors. Journal of Animal Ecology © 2016 British Ecological Society.

  2. An approach to coating and cathodic protection design on long distance gas pipeline

    Energy Technology Data Exchange (ETDEWEB)

    Bacchi, L.; Brugnetti, F.; Zanardo, F. [Snam Rete Gas, Milan (Italy); Castano, M. [Eni Gas and Power Div., Milan (Italy)

    2004-07-01

    This paper provided details of a pilot gas pipeline using X100 grade steel planned as part of the TAP project in Italy. The full-scale experimental line is located at a military base in Sardinia, and is comprised of two 48-inch diameter buried pipelines which extend for approximately 700 m. One of the lines is coated, has good cathodic protection (CP) and no mechanical damage. The other line has been mechanically damaged and has artificial defects in the pipe coating as well as areas that are subjected to bacteria cultures. The damaged line has also been divided into 3 parts that are protected with different levels of cathodic protection. The aim of the project is to examine the pipeline's susceptibility to environmentally assisted cracking, hydrogen embrittlement, and near-neutral stress corrosion cracking. A full scale burst test will be conducted on the undamaged line in order to analyze the mechanical behaviour of high-grade steel in optimal conditions. Three layer high density polyethylene (HDPE) and dual layer fusion bond epoxy lining are being considered by the project, which also aims to investigate the performance of field joint coatings. The project is also investigating power generation systems for CP. The CP systems will be monitored by periodic visits from technical operators as well as with the use of telemetry and remote control systems. Reference electrodes will be used to monitor the CP level of the pilot pipelines. A Cu-CuSO{sub 4} electrode will be used to monitor soil resistivity. It was concluded that the project will provide information concerning the reliability and duration of experimental electrodes, as well as the life cycle costs of corrosion protection in long-distance pipelines. 1 ref., 6 tabs., 3 figs.

  3. Cytokinins and auxin communicate nitrogen availability as long-distance signal molecules in pineapple (Ananas comosus).

    Science.gov (United States)

    Tamaki, Vívian; Mercier, Helenice

    2007-11-01

    This work aimed at identifying a possible role of phytohormones in long-distance (root-shoot) signaling under nitrogen deficiency. Three-months old pineapple plants were transferred from Murashige and Skoog (MS) medium to nitrogen-free MS (-N). During the first 24h on -N, 20 plants were harvested every 4h. After 30 days in -N, the remaining plants were transferred back to regular MS (+N) and 20 plants harvested every 4h for the first 24h. Following the harvests, endogenous levels of nitrate (NO(3)(-)), indole-3-acetic acid (IAA), isopentenyladenine (iP), isopentenyladenine riboside (iPR), zeatin (Z) and zeatin riboside (ZR) were analyzed in roots and leaves. In N-starved plants, the NO(3)(-) level dropped by 20% in roots between the first (4h) and the second harvest (8h). In leaves a reduction of 20% was found 4h later. Accumulation of IAA peaked in leaves at 16h. In roots, the accumulation of IAA only started at 16h while the leaf content was already in decline, which suggests that the hormone might have traveled from the leaves to the roots, communicating N-shortage. The contents of the four cytokinins were generally low in both, shoot and roots, and remained almost unchanged during the 24h of analysis. After N re-supply, roots showed a NO(3)(-) peak at 8h whereas the foliar concentration increased 4h later. Hormone levels in roots climaxed at 8h, this coinciding with the highest NO(3)(-) concentration. In leaf tissue, a dramatic accumulation was only observed for Z and ZR, and the peak was seen 4h later than in roots, suggesting that Z-type cytokinins might have traveled from the roots to the leaves. These findings provide evidence that there is a signaling pathway for N availability in pineapple plants, communicated upwards through cytokinins (N-supplemented plants) and downwards through auxin (N-starved plants).

  4. Interfacial air/water proton conduction from long distances by sulfolobus solfataricus archaeal bolaform lipids.

    Science.gov (United States)

    Vilalta, I; Gliozzi, A; Prats, M

    1996-08-15

    The stability, structural organization, and the ability to transfer protons long distances have been investigated in monolayers formed from archael bolaform lipids at the air/water interface. The lipids employed were the fractions GroR2Gro (R represents an acyl group with variable chain length typically consisting of 0-4 cyclopentane rings and 40 isoprenoid residues) and GroR2GroNon-Ol (Non-ol represents nonitol) extracted from Sulfolobus solfataricus by hydrolysis of the cytoplasmic membrane. GroR2-GroNon-ol films exhibit a very peculiar behaviour: the monolayer surface pressure increases with time, regardless of its low or high initial value. This finding is related to the possibility of GroR2GroNon-ol molecules to assume an upright (a metastable) or a U-shaped (stable) configuration. In the gaseous state and in the collapsed state of the film, no lateral proton conduction was observed. However, in the pressure range 0 < pi < 25 mN/m for GroR2Gro and 0 < pi < 30 mN/m for GroR2GroNon-ol monolayers, a lateral proton conduction at the air/water interface was observed. The structural organization of these bipolar lipids at the air/water interface can be related to the lateral proton conduction; it is possible to conclude that whatever configuration these lipids may adopt, they are able to structure the air/water interface in a hydrogen bond network that supports lateral proton conduction. This process may be ascribed to a percolation phenomenon occurring when the polar lipid head groups form a structured lattice of hydrogen bonds.

  5. Long-distance transport of cadmium from roots to leaves of Solanum melongena.

    Science.gov (United States)

    Qin, Qin; Li, Xuemei; Zhuang, Jie; Weng, Liping; Liu, Wan; Tai, Peidong

    2015-12-01

    In this study, the characteristics of cadmium (Cd) uptake by roots and translocation from roots to leaves of two eggplant species (Solanum melongena and Solanum torvum) under relatively low Cd concentrations were investigated using stable (108)Cd isotope through a number of hydroponic experiments. The uptake and translocation of (108)Cd was compared with those of (70)Zn and (15)N. The results showed more (108)Cd was loaded to the vascular channels and translocated upward to the leaves in S. melongena than in S. torvum, while the (108)Cd concentrations were significantly lower in the roots of S. melongena than in S. torvum. When the phloem and xylem were wounded by grafting treatments, the foliar (108)Cd concentrations were decreased by more than 66% regardless of the rootstock species, whereas the uptake of (108)Cd in the root was not inhibited by grafting. Similar grafting effects were observed for (70)Zn. Hence, wounding phloem and xylem by grafting disturbed the upward transport of (108)Cd and (70)Zn to the eggplant leaves. Similarly, interruption of the phloem by the girdling treatment reduced the concentrations of (108)Cd in the leaves of S. melongena by approximately 51%, though the uptake of (108)Cd by roots was not reduced by the interruption of phloem. In contrast, neither (70)Zn concentrations nor stable N isotope ratio (δ(15)N) values in the roots and leaves of S. melongena were significantly influenced by the interruption of phloem. In conclusion, the phloem played a dominant role in the long-distance transport of Cd from the root to the leaf of S. melongena, whereas the xylem was the main channel for the translocation of Zn and N.

  6. Experimental quantification of long distance dispersal potential of aquatic snails in the gut of migratory birds.

    Directory of Open Access Journals (Sweden)

    Casper H A van Leeuwen

    Full Text Available Many plant seeds and invertebrates can survive passage through the digestive system of birds, which may lead to long distance dispersal (endozoochory in case of prolonged retention by moving vectors. Endozoochorous dispersal by waterbirds has nowadays been documented for many aquatic plant seeds, algae and dormant life stages of aquatic invertebrates. Anecdotal information indicates that endozoochory is also possible for fully functional, active aquatic organisms, a phenomenon that we here address experimentally using aquatic snails. We fed four species of aquatic snails to mallards (Anas platyrhynchos, and monitored snail retrieval and survival over time. One of the snail species tested was found to survive passage through the digestive tract of mallards as fully functional adults. Hydrobia (Peringia ulvae survived up to five hours in the digestive tract. This suggests a maximum potential transport distance of up to 300 km may be possible if these snails are taken by flying birds, although the actual dispersal distance greatly depends on additional factors such as the behavior of the vectors. We put forward that more organisms that acquired traits for survival in stochastic environments such as wetlands, but not specifically adapted for endozoochory, may be sufficiently equipped to successfully pass a bird's digestive system. This may be explained by a digestive trade-off in birds, which maximize their net energy intake rate rather than digestive efficiency, since higher efficiency comes with the cost of prolonged retention times and hence reduces food intake. The resulting lower digestive efficiency allows species like aquatic snails, and potentially other fully functional organisms without obvious dispersal adaptations, to be transported internally. Adopting this view, endozoochorous dispersal may be more common than up to now thought.

  7. Emergence of long distance bird migrations: a new model integrating global climate changes

    Science.gov (United States)

    Louchart, Antoine

    2008-12-01

    During modern birds history, climatic and environmental conditions have evolved on wide scales. In a continuously changing world, landbirds annual migrations emerged and developed. However, models accounting for the origins of these avian migrations were formulated with static ecogeographic perspectives. Here I reviewed Cenozoic paleoclimatic and paleontological data relative to the palearctic paleotropical long distance (LD) migration system. This led to propose a new model for the origin of LD migrations, the ‘shifting home’ model (SHM). It is based on a dynamic perspective of climate evolution and may apply to the origins of most modern migrations. Non-migrant tropical African bird taxa were present at European latitudes during most of the Cenozoic. Their distribution limits shifted progressively toward modern tropical latitudes during periods of global cooling and increasing seasonality. In parallel, decreasing winter temperatures in the western Palearctic drove shifts of population winter ranges toward the equator. I propose that this induced the emergence of most short distance migrations, and in turn LD migrations. This model reconciliates ecologically tropical ancestry of most LD migrants with predominant winter range shifts, in accordance with requirements for heritable homing. In addition, it is more parsimonious than other non-exclusive models. Greater intrinsic plasticity of winter ranges implied by the SHM is supported by recently observed impacts of the present global warming on migrating birds. This may induce particular threats to some LD migrants. The ancestral, breeding homes of LD migrants were not ‘northern’ or ‘southern’ but shifted across high and middle latitudes while migrations emerged through winter range shifts themselves.

  8. Ultrafast fault-tolerant long-distance quantum communication with static linear optics

    Science.gov (United States)

    Ewert, Fabian; van Loock, Peter

    2017-01-01

    We present an in-depth analysis regarding the error resistance and optimization of our all-optical Bell measurement and ultrafast long-distance quantum communication scheme proposed by Ewert, Bergmann, and van Loock [Phys. Rev. Lett. 117, 210501 (2016), 10.1103/PhysRevLett.117.210501]. In order to promote our previous proposal from loss to fault tolerance, we introduce a general and compact formalism that can also be applied to other related schemes {including non-all-optical ones such as that of Muralidharan et al. [Phys. Rev. Lett. 112, 250501 (2014), 10.1103/PhysRevLett.112.250501]}. With the help of this new representation we show that our communication protocol does not only counteract the inevitable photon loss during channel transmission, but is also able to resist common experimental errors such as Pauli-type errors (bit and phase flips) and detector inefficiencies (losses and dark counts). Furthermore, we demonstrate that on the physical level of photonic qubits the choice of the standard linear optical Bell measurement with its limited efficiency is optimal for our setting in the sense that, apart from their potential use in state preparation, more advanced Bell measurements yield only a small decrease in resource consumption. We devise two state generation schemes that provide the required ancillary encoded Bell states (quasi-)on-demand at every station. The schemes are either based on nonlinear optics or on linear optics with multiplexing and exhibit resource costs that scale linearly or less than quadratic with the number of photons per encoded qubit, respectively. Finally, we show that it is possible to operate our communication scheme with on-off detectors instead of employing photon-number-resolving detectors.

  9. Distinct palisade tissue development processes promoted by leaf autonomous signalling and long-distance signalling in Arabidopsis thaliana.

    Science.gov (United States)

    Munekage, Yuri Nakajima; Inoue, Shio; Yoneda, Yuki; Yokota, Akiho

    2015-06-01

    Plants develop palisade tissue consisting of cylindrical mesophyll cells located at the adaxial side of leaves in response to high light. To understand high light signalling in palisade tissue development, we investigated leaf autonomous and long-distance signal responses of palisade tissue development using Arabidopsis thaliana. Illumination of a developing leaf with high light induced cell height elongation, whereas illumination of mature leaves with high light increased cell density and suppressed cell width expansion in palisade tissue of new leaves. Examination using phototropin1 phototropin2 showed that blue light signalling mediated by phototropins was involved in cell height elongation of the leaf autonomous response rather than the cell density increase induced by long-distance signalling. Hydrogen peroxide treatment induced cylindrical palisade tissue cell formation in both a leaf autonomous and long-distance manner, suggesting involvement of oxidative signals. Although constitutive expression of transcription factors involved in systemic-acquired acclimation to excess light, ZAT10 and ZAT12, induced cylindrical palisade tissue cell formation, knockout of these genes did not affect cylindrical palisade tissue cell formation. We conclude that two distinct signalling pathways - leaf autonomous signalling mostly dependent on blue light signalling and long-distance signalling from mature leaves that sense high light and oxidative stress - control palisade tissue development in A. thaliana.

  10. On the participation in medium- and long-distance travel: a decomposition analysis for the UK and the Netherlands

    NARCIS (Netherlands)

    Limtanakool, N.; Dijst, M.J.; Schwanen, T.

    2006-01-01

    Social and economic benefits have accrued from medium- and long-distance travel, but at the expense of the environment. Since the travel behaviour literature tends to concentrate on shortdistance trips or trips within daily urban systems, a better understanding of the factors shaping medium- and lon

  11. Long-distance travel and urban systems : Development of a theoretical and methodological framework and empirical evidence from Western Europe

    NARCIS (Netherlands)

    Limtanakool, N.

    2006-01-01

    It is evident in many countries worldwide that both the frequency and the distance of personal travel have grown concurrently with the proliferation of telecommunications that might substitute for travel. While the understanding of the determinants of long-distance travel is still limited in the lit

  12. Fuel use and metabolic response to endurance exercise : a wind tunnel study of a long-distance migrant shorebird

    NARCIS (Netherlands)

    Jenni-Eiermann, Susanne; Jenni, Lukas; Kvist, Anders; Lindström, Åke; Piersma, Theunis; Visser, G. Henk

    2002-01-01

    This study examines fuel use and metabolism in a group of long-distance migrating birds, red knots Calidris canutus (Scolopacidae), flying under controlled conditions in a wind tunnel for up to 10 h. Data are compared with values for resting birds fasting for the same time. Plasma levels of free fat

  13. Long flights do not influence immune responses of a long-distance migrant bird : a wind-tunnel experiment

    NARCIS (Netherlands)

    Hasselquist, Dennis; Lindstrom, Ake; Jenni-Eiermann, Susi; Koolhaas, Anita; Piersma, Theunis; Lindström, Åke

    2007-01-01

    Heavy physical work can result in physiological stress and suppressed immune function. Accordingly, long-distance migrant birds that fly for thousands of km within days can be expected to show immunosuppression, and hence be more vulnerable to infections en route. The red knot Calidris canutus Linna

  14. Relationships between airborne pollen grains, wind direction and land cover using GIS and circular statistics.

    Science.gov (United States)

    Maya-Manzano, J M; Sadyś, M; Tormo-Molina, R; Fernández-Rodríguez, S; Oteros, J; Silva-Palacios, I; Gonzalo-Garijo, A

    2017-04-15

    Airborne bio-aerosol content (mainly pollen and spores) depends on the surrounding vegetation and weather conditions, particularly wind direction. In order to understand this issue, maps of the main land cover in influence areas of 10km in radius surrounding pollen traps were created. Atmospheric content of the most abundant 14 pollen types was analysed in relation to the predominant wind directions measured in three localities of SW of Iberian Peninsula, from March 2011 to March 2014. Three Hirst type traps were used for aerobiological monitoring. The surface area for each land cover category was calculated and wind direction analysis was approached by using circular statistics. This method could be helpful for estimating the potential risk of exposure to various pollen types. Thus, the main land cover was different for each monitoring location, being irrigated crops, pastures and hardwood forests the main categories among 11 types described. Comparison of the pollen content with the predominant winds and land cover shows that the atmospheric pollen concentration is related to some source areas identified in the inventory. The study found that some pollen types (e.g. Plantago, Fraxinus-Phillyrea, Alnus) come from local sources but other pollen types (e.g. Quercus) are mostly coming from longer distances. As main conclusions, airborne particle concentrations can be effectively split by addressing wind with circular statistics. By combining circular statistics and GIS method with aerobiological data, we have created a useful tool for understanding pollen origin. Some pollen loads can be explained by immediate surrounding landscape and observed wind patterns for most of the time. However, other factors like medium or long-distance transport or even pollen trap location within a city, may occasionally affect the pollen load recorded using an air sampler.

  15. Synoptic climatology of the long-distance dispersal of white pine blister rust II. Combination of surface and upper-level conditions

    Science.gov (United States)

    Frank, K. L.; Geils, B. W.; Kalkstein, L. S.; Thistle, H. W.

    2008-09-01

    An invasive forest pathogen, Cronartium ribicola, white pine blister rust (WPBR), is believed to have arrived in the Sacramento Mountains of south-central New Mexico about 1970. Epidemiological and genetic evidence supports the hypothesis that introduction was the result of long-distance dispersal (LDD) by atmospheric transport from California. This study applies a method to identify the atmospheric conditions favorable for rust transport and infection. An upper level synoptic classification (ULSC) identifies patterns of upper-level flow favorable for the transport of rust spores from a source to a target. Transport data are coupled with data for surface conditions favorable for infection at a designated target. A resulting calendar lists likelihood classes for establishment by four-times-daily observations during a dispersal season from April through July in the years 1965 to 1974. The single most-favorable period for transport and infection at the New Mexico site was identified as 1 15 June 1969. Five additional sites in the western United States with susceptible white pine populations and known infestation status were then evaluated to verify the model. Only the infested sites exhibit an establishment likelihood of “high” or “very high.” This suggests that the methodology correctly identifies locations with elevated establishment likelihood. Finally, likelihoods at nine additional points in the southwestern United States are determined and used to map regional patterns of transport, infection and establishment. The ULSC combined with appropriate surface meteorological data could be used to further investigate transport and infection, identify other areas at risk, assess the potential for gene flow of WPBR and evaluate long-distance dispersal of other pathogens.

  16. Potential benefits of long-distance electricity transmission in China for air quality and climate

    Science.gov (United States)

    Peng, W.; Mauzerall, D. L.; Yuan, J.; Zhao, Y.; Lin, M.; Zhang, Q.

    2015-12-01

    China is expanding west-to-east long-distance electricity transmission capacity with the aim of reducing eastern coal power production and resulting air pollution. In addition to coal power, this new grid capacity can be used to transport renewable-generated electricity with resulting climate co-benefits. Here we use an integrated assessment to evaluate the air quality and climate benefits of twelve proposed transmission lines in China, and compare two energy-by-wire strategies that transmit 1) only coal power (Coal-by-wire, CbW) or 2) combined renewable plus coal power (Renewable and coal-by-wire, (RE+C)bW), with 3) the current practice of transporting coal by rail for conversion to electricity near eastern demand centers (Coal-by-rail, CbR). Based on a regional atmospheric chemistry model, WRF-Chem, electricity transmission through the proposed lines leads to 2-3 μg/m3 (2-7%) reduction in the annual mean concentrations of fine particulate matter (PM2.5) in the eastern provinces relative to 2010 levels, roughly ~1 μg/m3 greater than the reduction achieved in CbR where dirty coal units are locally replaced with efficient ones. Although the eastern air quality improvement is similar irrespective of the fuel source to power the lines, adding coal generation results in up to 3% increase in annual mean PM2.5 levels in some exporting provinces, whereas such increase is not observed when most added capacity is renewable-based. Counting both the economic value of reduced carbon emissions and the health-related air quality benefits can significantly improve the cost-effectiveness of transmitting both renewable and coal power. Comparing (RE+C)bW with the two coal-based options, we find not only 20% larger reduction in air-pollution-related deaths, but also three times greater reduction in CO2 emissions. Our study hence demonstrates the significance of coordinating renewable energy planning with transmission planning to simultaneously tackle air pollution and climate

  17. Role of Clay Minerals in Long-Distance Transport of Landslides in Valles Marineris, Mars

    Science.gov (United States)

    Watkins, J.; Ehlmann, B. L.; Yin, A.

    2014-12-01

    Long-runout (> 50 km) subaerial landslides are rare on Earth, but are common features episodically shaping Mars' Valles Marineris (VM) trough system over the past 3.5 billion years. They display two end-member morphologies: a thick-skinned inner zone, characterized by fault-bounded, rotated blocks near their source region, and a thin-skinned, exceptionally long-runout outer zone, characterized by thin sheets spreading over 10s of km across the trough floor. Four decades of studies on the latter have resulted in two main competing hypotheses to explain their long-distance transport: (1) movement of landslides over layers of trapped air or soft materials containing ice or snow, enabling basal lubrication, and (2) fluidization of landslide materials with or without the presence of water and volatiles. To address this issue, we examine the mineralogic composition of landslides across VM using Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) near-infrared spectral data analysis coupled with detailed geologic mapping and morphometric analysis of satellite images. Our survey reveals a general correlation between transport distance, significant lateral spreading, and the presence of hydrated silicates among VM landslides. Given that smectite clay absorbs water into its layered crystal structure and can reduce the friction coefficient by a factor of three v. that of dry rocks, these results suggest that hydrated silicates played a decisive role in facilitating long-runout landslide transport in VM. We propose that, concurrent with downslope failure and sliding of broken trough-wall rock, frontal landslide masses overrode and entrained hydrated-silicate-bearing trough-floor deposits, lubricating the basal sliding zones and permitting the landslide outer zones to spread laterally while moving forward over the low-friction surface. The key participation of hydrated silicates in episodic, sustained landslide activity throughout the canyon implies that clay minerals

  18. Secondary wind dispersal enhances long-distance dispersal of an invasive species in urban road corridors

    Directory of Open Access Journals (Sweden)

    Ingo Kowarik

    2011-08-01

    irregular surfaces slowed down or terminated SWD. During the observation period, 17% of released samaras accumulated in patches with a planted tree. Some were recaptured within the median strip and thus must have been lifted and moved over four lanes of heavy traffic. Our results suggest that impervious surfaces within road corridors can function as powerful avenues of wind-mediated long-distance dispersal and may counteract fragmentation of urban habitats. This also offers a functional explanation for the invasion success of Ailanthus at isolated urban sites.

  19. The Localization of Long-Distance Dependency Components: Integrating the Focal-lesion and Neuroimaging Record.

    Science.gov (United States)

    Piñango, Maria M; Finn, Emily; Lacadie, Cheryl; Constable, R Todd

    2016-01-01

    In the sentence "The captain who the sailor greeted is tall," the connection between the relative pronoun and the object position of greeted represents a long-distance dependency (LDD), necessary for the interpretation of "the captain" as the individual being greeted. Whereas the lesion-based record shows preferential involvement of only the left inferior frontal (LIF) cortex, associated with Broca's aphasia, during real-time comprehension of LDDs, the neuroimaging record shows additional involvement of the left posterior superior temporal (LPST) and lower parietal cortices, which are associated with Wernicke's aphasia. We test the hypothesis that this localization incongruence emerges from an interaction of memory and linguistic constraints involved in the real-time implementation of these dependencies and which had not been previously isolated. Capitalizing on a long-standing psycholinguistic understanding of LDDs as the workings of an active filler, we distinguish two linguistically defined mechanisms: GAP-search, triggered by the retrieval of the relative pronoun, and GAP-completion, triggered by the retrieval of the embedded verb. Each mechanism is hypothesized to have distinct memory demands and given their distinct linguistic import, potentially distinct brain correlates. Using fMRI, we isolate the two mechanisms by analyzing their relevant sentential segments as separate events. We manipulate LDD-presence/absence and GAP-search type (direct/indirect) reflecting the absence/presence of intervening islands. Results show a direct GAP-search-LIF cortex correlation that crucially excludes the LPST cortex. Notably, indirect GAP-search recruitment is confined to supplementary-motor and lower-parietal cortex indicating that GAP presence alone is not enough to engage predictive functions in the LIF cortex. Finally, GAP-completion shows recruitment implicating the dorsal pathway including: the supplementary motor cortex, left supramarginal cortex, precuneus, and

  20. The Australian Bogong Moth Agrotis infusa: A Long-Distance Nocturnal Navigator

    Directory of Open Access Journals (Sweden)

    Eric Warrant

    2016-04-01

    Full Text Available The nocturnal Bogong moth (Agrotis infusa is an iconic and well-known Australian insect that is also a remarkable nocturnal navigator. Like the Monarch butterflies of North America, Bogong moths make a yearly migration over enormous distances, from southern Queensland, western and northwestern New South Wales (NSW and western Victoria, to the alpine regions of NSW and Victoria. After emerging from their pupae in early spring, adult Bogong moths embark on a long nocturnal journey towards the Australian Alps, a journey that can take many days or even weeks and cover over 1000 km. Once in the Alps (from the end of September, Bogong moths seek out the shelter of selected and isolated high ridge-top caves and rock crevices (typically at elevations above 1800 m. In hundreds of thousands, moths line the interior walls of these cool alpine caves where they “hibernate” over the summer months (referred to as “estivation”. Towards the end of the summer (February and March, the same individuals that arrived months earlier leave the caves and begin their long return trip to their breeding grounds. Once there, moths mate, lay eggs and die. The moths that hatch in the following spring then repeat the migratory cycle afresh. Despite having had no previous experience of the migratory route, these moths find their way to the Alps and locate their estivation caves that are dotted along the high alpine ridges of southeastern Australia. How naïve moths manage this remarkable migratory feat still remains a mystery, although there are many potential sensory cues along the migratory route that moths might rely on during their journey, including visual, olfactory, mechanical and magnetic cues. Here we review our current knowledge of the Bogong moth, including its natural history, its ecology, its cultural importance to the Australian Aborigines and what we understand about the sensory basis of its long-distance nocturnal migration. From this analysis it becomes

  1. The Australian Bogong moth Agrotis infusa: A long-distance nocturnal navigator

    Directory of Open Access Journals (Sweden)

    Eric eWarrant

    2016-04-01

    Full Text Available The nocturnal Bogong moth (Agrotis infusa is an iconic and well-known Australian insect that is also a remarkable nocturnal navigator. Like the Monarch butterflies of North America, Bogong moths make a yearly migration over enormous distances, from southern Queensland, western and northwestern New South Wales (NSW and western Victoria, to the alpine regions of NSW and Victoria. After emerging from their pupae in early spring, adult Bogong moths embark on a long nocturnal journey towards the Australian Alps, a journey that can take many days or even weeks and cover over 1000 km. Once in the Alps (from the end of September, Bogong moths seek out the shelter of selected and isolated high ridge-top caves and rock crevices (typically at elevations above 1800 m. In hundreds of thousands, moths line the interior walls of these cool alpine caves where they hibernate over the summer months (referred to as aestivation. Towards the end of the summer (February and March, the same individuals that arrived months earlier leave the caves and begin their long return trip to their breeding grounds. Once there, moths mate, lay eggs and die. The moths that hatch in the following spring then repeat the migratory cycle afresh. Despite having had no previous experience of the migratory route, these moths find their way to the Alps and locate their aestivation caves that are dotted along the high alpine ridges of southeastern Australia. How naïve moths manage this remarkable migratory feat still remains a mystery, although there are many potential sensory cues along the migratory route that moths might rely on during their journey, including visual, olfactory, mechanical and magnetic cues. Here we review our current knowledge of the Bogong moth, including its natural history, its ecology, its cultural importance to the Australian Aborigines and what we understand about the sensory basis of its long-distance nocturnal migration. From this analysis it becomes clear

  2. Pollen tube germination in maize does not require transcriptomic changes

    Science.gov (United States)

    One objective for our group is to better understand the molecular and genetic basis of pollen and pollen tube function, given its critical role in seed production and its importance as a means of gene flow between plant populations. We compared gene expression levels in seedlings...

  3. Fluorescent dye particles as pollen analogues for measuring pollen dispersal in an insect-pollinated forest herb.

    Science.gov (United States)

    Van Rossum, Fabienne; Stiers, Iris; Van Geert, Anja; Triest, Ludwig; Hardy, Olivier J

    2011-03-01

    In flowering plants, pollen dispersal is often the major contributing component to gene flow, hence a key parameter in conservation genetics and population biology. A cost-effective method to assess pollen dispersal consists of monitoring the dispersal of fluorescent dyes used as pollen analogues. However, few comparisons between dye dispersal and realized pollen dispersal have been performed to validate the method. We investigated pollen dispersal in two small populations of the insect-pollinated herb Primula elatior from urban forest fragments using direct (paternity analyses based on microsatellite DNA markers) and indirect (fluorescent dyes) methods. We compared these methods using two approaches, testing for the difference between the distance distributions of observed dispersal events and estimating parameters of a dispersal model, and related these results to dye dispersal patterns in three large populations. Dye and realized (based on paternity inference) pollen dispersal showed exponential decay distributions, with 74.2-94.8% of the depositions occurring at pollen dispersal distributions. The best-fitting parameters characterizing the dye dispersal model were consistent with those obtained for realized pollen dispersal. Hence, the fluorescent dye method may be considered as reliable to infer realized pollen dispersal for forest herbs such as P. elatior. However, our simulations reveal that large sample sizes are needed to detect moderate differences between dye and realized pollen dispersal patterns because the estimation of dispersal parameters suffers low precision.

  4. Engineering and performance standards parameters for long distance road transport in the United States: the special case of horses

    Directory of Open Access Journals (Sweden)

    Carolyn L. Stull

    2008-03-01

    Full Text Available The transportation conditions of slaughter horses for human consumption have become a public and regulatory issue in the United States in the last two decades. Federal regulations were developed partially using the results of funded research projects that examined the types of vehicles, characteristics of slaughter horse candidates, types of injuries during transport, duration of transit, stocking densities and other behavioural and physiological indices during long-distance road transport. Additionally, the physiological responses of horses travelling long distances in vans while cross-tied by their halters in individual stalls were also studied. Both engineering- and performance-based standards were developed from the scientific studies and implemented in the federal regulations to ensure the humane movement of equines to slaughter facilities via commercial road transportation.

  5. Valuation of travel time for international long-distance travel - results from the Fehmarn Belt stated choice experiment

    DEFF Research Database (Denmark)

    Mabit, Stefan Lindhard; Rich, Jeppe; Burge, Peter

    2013-01-01

    significant interactions among travel cost and time, and journey characteristics, such as distance and duration. This had direct impact on the VTTS, which was shown to decrease with distance and duration. Thirdly, we found that air travel implies a higher average VTTS, which is to be expected but rarely......The geographical scope of travel varies from short distances in urban areas to long distances across cities and countries. While urban travel has been widely analysed in the literature, travel over longer distances and particularly across countries, has received much less attention. While this may...... be justified due to the number of travellers it cannot be justified when looking at the mileage consumption and its resulting environmental impacts. In this paper, we investigate international long-distance travel preferences related to travel between Scandinavia and Central Europe with particular focus...

  6. Measurement of the phase difference between short- and long-distance amplitudes in the [Formula: see text] decay.

    Science.gov (United States)

    Aaij, R; Adeva, B; Adinolfi, M; Ajaltouni, Z; Akar, S; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves, A A; Amato, S; Amerio, S; Amhis, Y; An, L; Anderlini, L; Andreassi, G; Andreotti, M; Andrews, J E; Appleby, R B; Archilli, F; d'Argent, P; Arnau Romeu, J; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Baalouch, M; Babuschkin, I; Bachmann, S; Back, J J; Badalov, A; Baesso, C; Baker, S; Balagura, V; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Baszczyk, M; Batozskaya, V; Batsukh, B; Battista, V; Bay, A; Beaucourt, L; Beddow, J; Bedeschi, F; Bediaga, I; Bel, L J; Bellee, V; Belloli, N; Belous, K; Belyaev, I; Ben-Haim, E; Bencivenni, G; Benson, S; Berezhnoy, A; Bernet, R; Bertolin, A; Betancourt, C; Betti, F; Bettler, M-O; van Beuzekom, M; Bezshyiko, Ia; Bifani, S; Billoir, P; Bird, T; Birnkraut, A; Bitadze, A; Bizzeti, A; Blake, T; Blanc, F; Blouw, J; Blusk, S; Bocci, V; Boettcher, T; Bondar, A; Bondar, N; Bonivento, W; Bordyuzhin, I; Borgheresi, A; Borghi, S; Borisyak, M; Borsato, M; Bossu, F; Boubdir, M; Bowcock, T J V; Bowen, E; Bozzi, C; Braun, S; Britsch, M; Britton, T; Brodzicka, J; Buchanan, E; Burr, C; Bursche, A; Buytaert, J; Cadeddu, S; Calabrese, R; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Campora Perez, D H; Capriotti, L; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carniti, P; Carson, L; Carvalho Akiba, K; Casse, G; Cassina, L; Castillo Garcia, L; Cattaneo, M; Cavallero, G; Cenci, R; Chamont, D; Charles, M; Charpentier, Ph; Chatzikonstantinidis, G; Chefdeville, M; Chen, S; Cheung, S-F; Chobanova, V; Chrzaszcz, M; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coco, V; Cogan, J; Cogneras, E; Cogoni, V; Cojocariu, L; Collazuol, G; Collins, P; Comerma-Montells, A; Contu, A; Cook, A; Coombs, G; Coquereau, S; Corti, G; Corvo, M; Costa Sobral, C M; Couturier, B; Cowan, G A; Craik, D C; Crocombe, A; Cruz Torres, M; Cunliffe, S; Currie, R; D'Ambrosio, C; Da Cunha Marinho, F; Dall'Occo, E; Dalseno, J; David, P N Y; Davis, A; De Bruyn, K; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Serio, M; De Simone, P; Dean, C-T; Decamp, D; Deckenhoff, M; Del Buono, L; Demmer, M; Dendek, A; Derkach, D; Deschamps, O; Dettori, F; Dey, B; Di Canto, A; Dijkstra, H; Dordei, F; Dorigo, M; Dosil Suárez, A; Dovbnya, A; Dreimanis, K; Dufour, L; Dujany, G; Dungs, K; Durante, P; Dzhelyadin, R; Dziurda, A; Dzyuba, A; Déléage, N; Easo, S; Ebert, M; Egede, U; Egorychev, V; Eidelman, S; Eisenhardt, S; Eitschberger, U; Ekelhof, R; Eklund, L; Ely, S; Esen, S; Evans, H M; Evans, T; Falabella, A; Farley, N; Farry, S; Fay, R; Fazzini, D; Ferguson, D; Fernandez Prieto, A; Ferrari, F; Ferreira Rodrigues, F; Ferro-Luzzi, M; Filippov, S; Fini, R A; Fiore, M; Fiorini, M; Firlej, M; Fitzpatrick, C; Fiutowski, T; Fleuret, F; Fohl, K; Fontana, M; Fontanelli, F; Forshaw, D C; Forty, R; Franco Lima, V; Frank, M; Frei, C; Fu, J; Funk, W; Furfaro, E; Färber, C; Gallas Torreira, A; Galli, D; Gallorini, S; Gambetta, S; Gandelman, M; Gandini, P; Gao, Y; Garcia Martin, L M; García Pardiñas, J; Garra Tico, J; Garrido, L; Garsed, P J; Gascon, D; Gaspar, C; Gavardi, L; Gazzoni, G; Gerick, D; Gersabeck, E; Gersabeck, M; Gershon, T; Ghez, Ph; Gianì, S; Gibson, V; Girard, O G; Giubega, L; Gizdov, K; Gligorov, V V; Golubkov, D; Golutvin, A; Gomes, A; Gorelov, I V; Gotti, C; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graverini, E; Graziani, G; Grecu, A; Griffith, P; Grillo, L; Gruberg Cazon, B R; Grünberg, O; Gushchin, E; Guz, Yu; Gys, T; Göbel, C; Hadavizadeh, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Haines, S C; Hall, S; Hamilton, B; Han, X; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; Hatch, M; He, J; Head, T; Heister, A; Hennessy, K; Henrard, P; Henry, L; van Herwijnen, E; Heß, M; Hicheur, A; Hill, D; Hombach, C; Hopchev, H; Hulsbergen, W; Humair, T; Hushchyn, M; Hutchcroft, D; Idzik, M; Ilten, P; Jacobsson, R; Jaeger, A; Jalocha, J; Jans, E; Jawahery, A; Jiang, F; John, M; Johnson, D; Jones, C R; Joram, C; Jost, B; Jurik, N; Kandybei, S; Karacson, M; Kariuki, J M; Karodia, S; Kecke, M; Kelsey, M; Kenzie, M; Ketel, T; Khairullin, E; Khanji, B; Khurewathanakul, C; Kirn, T; Klaver, S; Klimaszewski, K; Koliiev, S; Kolpin, M; Komarov, I; Koopman, R F; Koppenburg, P; Kosmyntseva, A; Kozachuk, A; Kozeiha, M; Kravchuk, L; Kreplin, K; Kreps, M; Krokovny, P; Kruse, F; Krzemien, W; Kucewicz, W; Kucharczyk, M; Kudryavtsev, V; Kuonen, A K; Kurek, K; Kvaratskheliya, T; Lacarrere, D; Lafferty, G; Lai, A; Lanfranchi, G; Langenbruch, C; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Leflat, A; Lefrançois, J; Lefèvre, R; Lemaitre, F; Lemos Cid, E; Leroy, O; Lesiak, T; Leverington, B; Li, T; Li, Y; Likhomanenko, T; Lindner, R; Linn, C; Lionetto, F; Liu, X; Loh, D; Longstaff, I; Lopes, J H; Lucchesi, D; Lucio Martinez, M; Luo, H; Lupato, A; Luppi, E; Lupton, O; Lusiani, A; Lyu, X; Machefert, F; Maciuc, F; Maev, O; Maguire, K; Malde, S; Malinin, A; Maltsev, T; Manca, G; Mancinelli, G; Manning, P; Maratas, J; Marchand, J F; Marconi, U; Marin Benito, C; Marinangeli, M; Marino, P; Marks, J; Martellotti, G; Martin, M; Martinelli, M; Martinez Santos, D; Martinez Vidal, F; Martins Tostes, D; Massacrier, L M; Massafferri, A; Matev, R; Mathad, A; Mathe, Z; Matteuzzi, C; Mauri, A; Maurice, E; Maurin, B; Mazurov, A; McCann, M; McNab, A; McNulty, R; Meadows, B; Meier, F; Meissner, M; Melnychuk, D; Merk, M; Merli, A; Michielin, E; Milanes, D A; Minard, M-N; Mitzel, D S; Mogini, A; Molina Rodriguez, J; Monroy, I A; Monteil, S; Morandin, M; Morawski, P; Mordà, A; Morello, M J; Morgunova, O; Moron, J; Morris, A B; Mountain, R; Muheim, F; Mulder, M; Mussini, M; Müller, D; Müller, J; Müller, K; Müller, V; Naik, P; Nakada, T; Nandakumar, R; Nandi, A; Nasteva, I; Needham, M; Neri, N; Neubert, S; Neufeld, N; Neuner, M; Nguyen, T D; Nguyen-Mau, C; Nieswand, S; Niet, R; Nikitin, N; Nikodem, T; Nogay, A; Novoselov, A; O'Hanlon, D P; Oblakowska-Mucha, A; Obraztsov, V; Ogilvy, S; Oldeman, R; Onderwater, C J G; Otalora Goicochea, J M; Otto, A; Owen, P; Oyanguren, A; Pais, P R; Palano, A; Palombo, F; Palutan, M; Papanestis, A; Pappagallo, M; Pappalardo, L L; Parker, W; Parkes, C; Passaleva, G; Pastore, A; Patel, G D; Patel, M; Patrignani, C; Pearce, A; Pellegrino, A; Penso, G; Pepe Altarelli, M; Perazzini, S; Perret, P; Pescatore, L; Petridis, K; Petrolini, A; Petrov, A; Petruzzo, M; Picatoste Olloqui, E; Pietrzyk, B; Pikies, M; Pinci, D; Pistone, A; Piucci, A; Placinta, V; Playfer, S; Plo Casasus, M; Poikela, T; Polci, F; Poluektov, A; Polyakov, I; Polycarpo, E; Pomery, G J; Popov, A; Popov, D; Popovici, B; Poslavskii, S; Potterat, C; Price, E; Price, J D; Prisciandaro, J; Pritchard, A; Prouve, C; Pugatch, V; Puig Navarro, A; Punzi, G; Qian, W; Quagliani, R; Rachwal, B; Rademacker, J H; Rama, M; Ramos Pernas, M; Rangel, M S; Raniuk, I; Ratnikov, F; Raven, G; Redi, F; Reichert, S; Dos Reis, A C; Remon Alepuz, C; Renaudin, V; Ricciardi, S; Richards, S; Rihl, M; Rinnert, K; Rives Molina, V; Robbe, P; Rodrigues, A B; Rodrigues, E; Rodriguez Lopez, J A; Rodriguez Perez, P; Rogozhnikov, A; Roiser, S; Rollings, A; Romanovskiy, V; Romero Vidal, A; Ronayne, J W; Rotondo, M; Rudolph, M S; Ruf, T; Ruiz Valls, P; Saborido Silva, J J; Sadykhov, E; Sagidova, N; Saitta, B; Salustino Guimaraes, V; Sanchez Mayordomo, C; Sanmartin Sedes, B; Santacesaria, R; Santamarina Rios, C; Santimaria, M; Santovetti, E; Sarti, A; Satriano, C; Satta, A; Saunders, D M; Savrina, D; Schael, S; Schellenberg, M; Schiller, M; Schindler, H; Schlupp, M; Schmelling, M; Schmelzer, T; Schmidt, B; Schneider, O; Schopper, A; Schubert, K; Schubiger, M; Schune, M-H; Schwemmer, R; Sciascia, B; Sciubba, A; Semennikov, A; Sergi, A; Serra, N; Serrano, J; Sestini, L; Seyfert, P; Shapkin, M; Shapoval, I; Shcheglov, Y; Shears, T; Shekhtman, L; Shevchenko, V; Siddi, B G; Silva Coutinho, R; Silva de Oliveira, L; Simi, G; Simone, S; Sirendi, M; Skidmore, N; Skwarnicki, T; Smith, E; Smith, I T; Smith, J; Smith, M; Snoek, H; Soares Lavra, L; Sokoloff, M D; Soler, F J P; Souza De Paula, B; Spaan, B; Spradlin, P; Sridharan, S; Stagni, F; Stahl, M; Stahl, S; Stefko, P; Stefkova, S; Steinkamp, O; Stemmle, S; Stenyakin, O; Stevens, H; Stevenson, S; Stoica, S; Stone, S; Storaci, B; Stracka, S; Straticiuc, M; Straumann, U; Sun, L; Sutcliffe, W; Swientek, K; Syropoulos, V; Szczekowski, M; Szumlak, T; T'Jampens, S; Tayduganov, A; Tekampe, T; Tellarini, G; Teubert, F; Thomas, E; van Tilburg, J; Tilley, M J; Tisserand, V; Tobin, M; Tolk, S; Tomassetti, L; Tonelli, D; Topp-Joergensen, S; Toriello, F; Tournefier, E; Tourneur, S; Trabelsi, K; Traill, M; Tran, M T; Tresch, M; Trisovic, A; Tsaregorodtsev, A; Tsopelas, P; Tully, A; Tuning, N; Ukleja, A; Ustyuzhanin, A; Uwer, U; Vacca, C; Vagnoni, V; Valassi, A; Valat, S; Valenti, G; Vazquez Gomez, R; Vazquez Regueiro, P; Vecchi, S; van Veghel, M; Velthuis, J J; Veltri, M; Veneziano, G; Venkateswaran, A; Vernet, M; Vesterinen, M; Viana Barbosa, J V; Viaud, B; Vieira, D; Vieites Diaz, M; Viemann, H; Vilasis-Cardona, X; Vitti, M; Volkov, V; Vollhardt, A; Voneki, B; Vorobyev, A; Vorobyev, V; Voß, C; de Vries, J A; Vázquez Sierra, C; Waldi, R; Wallace, C; Wallace, R; Walsh, J; Wang, J; Ward, D R; Wark, H M; Watson, N K; Websdale, D; Weiden, A; Whitehead, M; Wicht, J; Wilkinson, G; Wilkinson, M; Williams, M; Williams, M P; Williams, M; Williams, T; Wilson, F F; Wimberley, J; Wishahi, J; Wislicki, W; Witek, M; Wormser, G; Wotton, S A; Wraight, K; Wyllie, K; Xie, Y; Xing, Z; Xu, Z; Yang, Z; Yao, Y; Yin, H; Yu, J; Yuan, X; Yushchenko, O; Zarebski, K A; Zavertyaev, M; Zhang, L; Zhang, Y; Zhang, Y; Zhelezov, A; Zheng, Y; Zhu, X; Zhukov, V; Zucchelli, S

    2017-01-01

    A measurement of the phase difference between the short- and long-distance contributions to the [Formula: see text] decay is performed by analysing the dimuon mass distribution. The analysis is based on pp collision data corresponding to an integrated luminosity of 3[Formula: see text] collected by the LHCb experiment in 2011 and 2012. The long-distance contribution to the [Formula: see text] decay is modelled as a sum of relativistic Breit-Wigner amplitudes representing different vector meson resonances decaying to muon pairs, each with their own magnitude and phase. The measured phases of the [Formula: see text] and [Formula: see text] resonances are such that the interference with the short-distance component in dimuon mass regions far from their pole masses is small. In addition, constraints are placed on the Wilson coefficients, [Formula: see text] and [Formula: see text], and the branching fraction of the short-distance component is measured.

  7. Flagellin peptide flg22 gains access to long-distance trafficking in Arabidopsis via its receptor, FLS2

    Energy Technology Data Exchange (ETDEWEB)

    Jelenska, Joanna [University of Chicago; Greenberg, Jean T. [University of Chicago; Mirzadeh, Saed [ORNL; Davern, Sandra M. [ORNL; Standaert, Robert F. [ORNL

    2017-03-01

    Diverse pathogen-derived molecules, such as bacterial flagellin and its conserved peptide flg22, are recognized in plants via plasma membrane receptors and induce both local and systemic immune responses. The fate of such ligands was unknown: whether and by what mechanism(s) they enter plant cells and whether they are transported to distal tissues. We used biologically active fluorophore and radiolabeled peptides to establish that flg22 moves to distal organs with the closest vascular connections. Remarkably, entry into the plant cell via endocytosis together with the FLS2 receptor is needed for delivery to vascular tissue and long-distance transport of flg22. This contrasts with known routes of long distance transport of other non-cell-permeant molecules in plants, which require membrane-localized transporters for entry to vascular tissue. Thus, a plasma membrane receptor acts as a transporter to enable access of its ligand to distal trafficking routes.

  8. Foreword—welfare aspects of the long distance transportation of animals

    Directory of Open Access Journals (Sweden)

    Gardner Murray

    2008-03-01

    Full Text Available The long distance transport of animals within countries, between countries, across regions and across continents is increasing significantly and is also changing in nature. Statistics from the International Trade Centre of the United Nations Conference on Trade and Development and the World Trade Organization show that the value of world trade in live animals soared from US$8.7 billion in 2000 to US$12.1 billion in 2005. This enormous figure would be even greater if zoo animals, wildlife and illicit traffic were included.The history of animal transportation goes back thousands of years. It remains a legitimate practice to this day provided proper measures are taken to protect animal well-being and health. What has made circumstances different in the 21st century is the nature of transport (land, sea and air, the volume of traffic and a public awareness of welfare issues with demands that animals be treated humanely and in accordance with best contemporary practices. This increased volume of transport creates an unprecedented risk for disseminating infectious diseases, including those that may affect people.Key public concerns about animal welfare relate to factors such as a lack of infrastructure and investment in training, research and standards development, as well as indifference and neglect. The live animal transportation industries are threatened when these deficiencies are not corrected.Fortunately, a number of countries foresaw these problems and introduced a series of activities to support good animal welfare practices. Many recognised the clear connection between animal welfare, health and husbandry practice, and established policy settings to include these activities under a veterinary public and animal health umbrella. Recognising its critical importance, the World Organisation for Animal Health (Office International des Epizooties: OIE in its IVth Strategic plan (points a to b, identified animal welfare as a key issue and launched a

  9. Landscapes of Movement: Exploring a Contemporary Approah to Long-Distance Non-Motorized Backcountry Recreation Trail Planning

    OpenAIRE

    Binder, Christopher Monroe

    2015-01-01

    The discipline of long-distance non-motorized backcountry recreation trail planning and design has traditionally been defined by ad hoc, volunteer-based approaches. Despite the notable physical, affective, and cognitive benefits to individuals and populations derived from utilizing such trails, little progress has been made in framing a rigorous and contemporary method for their planning and design. Without such a framework, attempts in the field may fail to engage the advantages associated w...

  10. Age- and season-specific variation in local and long-distance movement behavior of golden eagles

    Science.gov (United States)

    Poessel, Sharon; Bloom, Peter H.; Braham, Melissa; Katzner, Todd Eli

    2016-01-01

    Animal movements can determine the population dynamics of wildlife. We used telemetry data to provide insight into the causes and consequences of local and long-distance movements of multiple age classes of conservation-reliant golden eagles (Aquila chrysaetos) in the foothills and mountains near Tehachapi, California. We estimated size and habitat-related correlates of 324 monthly 95 % home ranges and 317 monthly 50 % core areas for 25 birds moving locally over 2.5 years. We also calculated daily, hourly, and total distances traveled for the five of these birds that engaged in long-distance movements. Mean (±SD) monthly home-range size was 253.6 ± 429.4 km2 and core-area size was 26.4 ± 49.7 km2. Consistent with expectations, space used by pre-adults increased with age and was season-dependent but, unexpectedly, was not sex-dependent. For all ages and sexes, home ranges and core areas were dominated by both forest & woodland and shrubland & grassland habitat types. When moving long distances, eagles traveled up to 1588.4 km (1-way) in a season at highly variable speeds (63.7 ± 69.0 km/day and 5.2 ± 10.4 km/h) that were dependent on time of day. Patterns of long-distance movements by eagles were determined by age, yet these movements had characteristics of more than one previously described movement category (migration, dispersal, etc.). Our results provide a context for differentiating among types of movement behaviors and their population-level consequences and, thus, have implications for management and conservation of golden eagle populations.

  11. Characteristics of Loads of Cattle Stopping for Feed, Water and Rest during Long-Distance Transport in Canada

    OpenAIRE

    2014-01-01

    Simple Summary This study was designed to benchmark the characteristics of loads of cattle stopping for feed, water and rest during long distance transport in Canada. Another objective of this study was to determine how well these loads were following current Canadian regulations for the length of time animals can spend in transit, and how long they must be rested for. The majority of loads stopping for feed water and rest were transporting cattle to feedlots rather than processing plants. Al...

  12. Helicity conservation in inclusive nonleptonic decay B to VX Test of long-distance final state interaction

    CERN Document Server

    Suzuki, M

    2002-01-01

    The polarization measurement in the inclusive B decay provides us with a simple test of how much the long-distance final-state interaction takes place as the energy of the observed meson varies in the final state. We give the expectation of the perturbative QCD for the energy dependence of the helicity fractions in a semiquantitative form. Experiment will tell us for which decay processes the perturbative calculation should be applicable.

  13. The Major Roles Of Long Distance Bus Transport In Developing Countries With Emphasis On Addis Ababa, Ethiopia

    Directory of Open Access Journals (Sweden)

    Kassa Fekadu

    2015-03-01

    Full Text Available This article presents the major roles of long distance bus transport that radiates from Addis Ababa to the hinterland. The purpose is to assess and identify the major roles of Long Distance Bus Transport in Addis Ababa. The methodology is focused on both primary and secondary sources. The primary informants, who were principally distinguished from the passengers, operators, and key government officials from the transport office, include the head of bus terminal and Association, and selected experts. In terms of analysis, the qualitative approach was used by applying a thick description of the issue. The findings revealed that the availability of towns comes mainly because of the routes which give access and distribution of road passenger transport. The LDB (Long Distance Bus along the line has played a great role in the making of metropolitan linkage. The presence of these routes contributes more to the rise of urbanization and it has also played a role in the creation of towns and rural areas found around certain radius at the two sides of highways. Thus, it has a high probability for the expansion of urban sprawl and formation of conurbation in the future. The prescription for this study is to work with stakeholders to reduce the congestion of passengers in the terminals and the association also should serve the society 24/7 or 18/7.

  14. Ecological systems as computer networks: Long distance sea dispersal as a communication medium between island plant populations.

    Science.gov (United States)

    Sanaa, Adnen; Ben Abid, Samir; Boulila, Abdennacer; Messaoud, Chokri; Boussaid, Mohamed; Ben Fadhel, Najeh

    2016-06-01

    Ecological systems are known to exchange genetic material through animal species migration and seed dispersal for plants. Isolated plant populations have developed long distance dispersal as a means of propagation which rely on meteorological such as anemochory and hydrochory for coast, island and river bank dwelling species. Long distance dispersal by water, in particular, in the case of water current bound islands, calls for the analogy with computer networks, where each island and nearby mainland site plays the role of a network node, the water currents play the role of a transmission channel, and water borne seeds as data packets. In this paper we explore this analogy to model long distance dispersal of seeds among island and mainland populations, when traversed with water currents, in order to model and predict their future genetic diversity. The case of Pancratium maritimum L. populations in Tunisia is used as a proof of concept, where their genetic diversity is extrapolated. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  15. Genetic evidence for high propagule pressure and long-distance dispersal in monk parakeet (Myiopsitta monachus) invasive populations.

    Science.gov (United States)

    Gonçalves da Silva, Anders; Eberhard, Jessica R; Wright, Timothy F; Avery, Michael L; Russello, Michael A

    2010-08-01

    The monk parakeet (Myiopsitta monachus) is a successful invasive species that does not exhibit life history traits typically associated with colonizing species (e.g., high reproductive rate or long-distance dispersal capacity). To investigate this apparent paradox, we examined individual and population genetic patterns of microsatellite loci at one native and two invasive sites. More specifically, we aimed at evaluating the role of propagule pressure, sexual monogamy and long-distance dispersal in monk parakeet invasion success. Our results indicate little loss of genetic variation at invasive sites relative to the native site. We also found strong evidence for sexual monogamy from patterns of relatedness within sites, and no definite cases of extra-pair paternity in either the native site sample or the examined invasive site. Taken together, these patterns directly and indirectly suggest that high propagule pressure has contributed to monk parakeet invasion success. In addition, we found evidence for frequent long-distance dispersal at an invasive site (approximately 100 km) that sharply contrasted with previous estimates of smaller dispersal distance made in the native range (approximately 2 km), suggesting long-range dispersal also contributes to the species' spread within the United States. Overall, these results add to a growing body of literature pointing to the important role of propagule pressure in determining, and thus predicting, invasion success, especially for species whose life history traits are not typically associated with invasiveness.

  16. The importance of long-distance seed dispersal for the demography and distribution of a canopy tree species.

    Science.gov (United States)

    Caughlin, T Trevor; Ferguson, Jake M; Lichstein, Jeremy W; Bunyavejchewin, Sarayudh; Levey, Douglas J

    2014-04-01

    Long-distance seed dispersal (LDD) is considered a crucial determinant of tree distributions, but its effects depend on demographic processes that enable seeds to establish into adults and that remain poorly understood at large spatial scales. We estimated rates of seed arrival, germination, and survival and growth for a canopy tree species (Miliusa horsfieldii), in a landscape ranging from evergreen forest, where the species' abundance is high, to deciduous forest, where it is extremely low. We then used an individual-based model (IBM) to predict sapling establishment and to compare the relative importance of seed arrival and establishment in explaining the observed distribution of seedlings. Individuals in deciduous forest, far from the source population, experienced multiple benefits (e.g., increased germination rate and seedling survival and growth) from being in a habitat where conspecifics were almost absent. The net effect of these spatial differences in demographic processes was significantly higher estimated sapling establishment probabilities for seeds dispersed long distances into deciduous forest. Despite the high rate of establishment in this habitat, Miliusa is rare in the deciduous forest because the arrival of seeds at long distances from the source population is extremely low. Across the entire landscape, the spatial pattern of seed arrival is much more important than the spatial pattern of establishment for explaining observed seedling distributions. By using dynamic models to link demographic data to spatial patterns, we show that LDD plays a pivotal role in the distribution of this tree in its native habitat.

  17. Old nuclear symmetries and large N(c) as long distance symmetries in the two nucleon system

    CERN Document Server

    Arriola, E Ruiz

    2009-01-01

    Wigner and Serber symmetries for the two-nucleon system provide unique examples of long distance symmetries in Nuclear Physics, i.e. symmetries of the meson exchange forces broken only at arbitrarily small distances. We analyze the large Nc picture as a key ingredient to understand these, so far accidental, symmetries from a more fundamental viewpoint. A set of sum rules for NN phase-shifts, NN potentials and coarse grained V_lowk NN potentials can be derived showing Wigner SU(4) and Serber symmetries not to be fully compatible everywhere. The symmetry breaking pattern found from the partial wave analysis data, high quality potentials in coordinate space at long distances and their V_lowk relatives is analyzed on the light of large N(c) contracted SU(4) symmetry. Our results suggest using large Nc potentials as long distance ones for the two-nucleon system where the meson exchange potential picture is justified and known to be consistent with large Nc counting rules. We also show that potentials based on chir...

  18. Estimating the abundance of airborne pollen and fungal spores at variable elevations using an aircraft: how high can they fly?

    Science.gov (United States)

    Damialis, Athanasios; Kaimakamis, Evangelos; Konoglou, Maria; Akritidis, Ioannis; Traidl-Hoffmann, Claudia; Gioulekas, Dimitrios

    2017-03-01

    Airborne pollen and fungal spores are monitored mainly in highly populated, urban environments, for allergy prevention purposes. However, their sources can frequently be located outside cities’ fringes with more vegetation. So as to shed light to this paradox, we investigated the diversity and abundance of airborne pollen and fungal spores at various environmental regimes. We monitored pollen and spores using an aircraft and a car, at elevations from sea level to 2,000 m above ground, in the region of Thesssaloniki, Greece. We found a total of 24 pollen types and more than 15 spore types. Pollen and spores were detected throughout the elevational transect. Lower elevations exhibited higher pollen concentrations in only half of plant taxa and higher fungal spore concentrations in only Ustilago. Pinaceae and Quercus pollen were the most abundant recorded by airplane (>54% of the total). Poaceae pollen were the most abundant via car measurements (>77% of the total). Cladosporium and Alternaria spores were the most abundant in all cases (aircraft: >69% and >17%, car: >45% and >27%, respectively). We conclude that pollen and fungal spores can be diverse and abundant even outside the main source area, evidently because of long-distance transport incidents.

  19. Roman and early-medieval long-distance transport routes in north-western Europe : Modelling frequent-travel zones using a dendroarchaeological approach

    NARCIS (Netherlands)

    van Lanen, Rowin J.; Jansma, Esther; van Doesburg, Jan; Groenewoudt, Bert J.

    2016-01-01

    To what extent long-distance transport in north-western Europe changed after the Roman period is generally unknown. Few historical sources are available and existing archaeological records are unclear and sometimes conflicting. Traditionally, research on the long-distance exchange of goods mostly ha

  20. Roman and early-medieval long-distance transport routes in north-western Europe : Modelling frequent-travel zones using a dendroarchaeological approach

    NARCIS (Netherlands)

    van Lanen, Rowin J.; Jansma, Esther; van Doesburg, Jan; Groenewoudt, Bert J.

    2016-01-01

    To what extent long-distance transport in north-western Europe changed after the Roman period is generally unknown. Few historical sources are available and existing archaeological records are unclear and sometimes conflicting. Traditionally, research on the long-distance exchange of goods mostly

  1. Assessment of the Olea pollen and its major allergen Ole e 1 concentrations in the bioearosol of two biogeographical areas

    Science.gov (United States)

    Moreno-Grau, S.; Aira, M. J.; Elvira-Rendueles, B.; Fernández-González, M.; Fernández-González, D.; García-Sánchez, A.; Martínez-García, M. J.; Moreno, J. M.; Negral, L.; Vara, A.; Rodríguez-Rajo, F. J.

    2016-11-01

    The Olea pollen is currently an important allergy source. In some regions of Southern Spain, olive pollen is the main cause of allergic sensitization exceeding 40% of the sensitized individuals. Due to the scarce presence of olive trees in Northern Spain, limited to some cultivated fields in the South of the Galicia region where they also grow wild, only 8% of the sensitized individuals showed positive results for Olea pollen. The aim of the paper was to assess the behaviour pattern of the Olea pollen and its aeroallergens in the atmosphere, as this information could help us to improve the understanding and prevention of clinical symptoms. Airborne Olea pollen and Ole e 1 allergens were quantified in Cartagena (South-eastern Spain) and Ourense (North-western Spain). A volumetric pollen trap and a Burkard Cyclone sampler were used for pollen and allergen quantification. The Olea flowering took place in April or May in both biometeorological sampling areas. The higher concentrations were registered in the Southern area of Spain, for both pollen and Ole e 1, with values 8 times higher for pollen concentrations and 40 times higher for allergens. An alternate bearing pattern could be observed, characterized by years with high pollen values and low allergen concentrations and vice versa. Moreover, during some flowering seasons the allergen concentrations did not correspond to the atmospheric pollen values. Variations in weather conditions or Long Distance Transport (LDT) processes could explain the discordance. The back trajectory analysis shows that the most important contributions of pollen and allergens in the atmosphere are coincident with air masses passing through potential source areas. The exposure to olive pollen may not be synonym of antigen exposure.

  2. Intrapersonal Achievement Goals and Underlying Reasons among Long Distance Runners: Their Relation with Race Experience, Self-Talk, and Running Time

    Directory of Open Access Journals (Sweden)

    Jochen Delrue

    2016-07-01

    Full Text Available In a sample of long distance runners, we examined the role of type of intrapersonal achievement goals (i.e., approach versus avoidance and type of underlying reasons (i.e., autonomous and controlled, assessed prior to the race, as predictors of both pre-race (e.g., race appraisals and post-race (e.g., flow experience outcomes. Of 221 (62.4% males runners, 111 reported pursuing an intrapersonal-approach goal (i.e., doing better than before as their dominant or preferred achievement goal for the race, while 86 prioritized intrapersonal-avoidance goals (i.e., avoiding to perform worse than before. Regression and path analyses showed that the type of achievement goals predicted none of the outcomes except for running time, with approach goals predicting better performance when compared to avoidance goals. Path analyses revealed that autonomous reasons underlying intrapersonal goal pursuit related positively to pre-race challenge appraisals, performance and, via need satisfaction, to flow experience. Interestingly, controlled reasons positively related to pre-race threat appraisals and positively predicted both positive and negative self-talk, with both yielding opposing relations with flow. These findings complement past research on the intersection between the Achievement Goal Approach and Self-Determination Theory and highlight the value of studying the reasons underlying intrapersonal achievement goals.

  3. Contrasts between the phylogeographic patterns of chloroplast and nuclear DNA highlight a role for pollen-mediated gene flow in preventing population divergence in an East Asian temperate tree.

    Science.gov (United States)

    Bai, Wei-Ning; Wang, Wen-Ting; Zhang, Da-Yong

    2014-12-01

    Plant phylogeographic studies in East Asia have provided support for the biogeographic hypothesis that the complex landforms and climate of this region have provided substantial opportunities for allopatric speciation. However, most of these studies have been based on maternally inherited chloroplast DNA (cpDNA) markers and were therefore unable to reveal the role of pollen-mediated gene flow in preventing population divergence. Here, we investigate the phylogeography of the Chinese walnut Juglans cathayensis, a temperate deciduous tree widely distributed across disjunct montane sites in subtropical China. We genotyped 19 populations using seven cpDNA fragments and ten nuclear microsatellite loci and modeled the ecological niche of J. cathayensis. CpDNA analysis identified a total of nine haplotypes, and each of the 19 sampled populations was fixed for a single haplotype, displaying a prominent phylogeographic structure. The results of ecological niche modeling indicated that J. cathayensis populations survived the last glaciation in situ, although they were probably more fragmented than today. In contrast, we detected a much weaker, but nonetheless clear, genetic structure based on nuclear microsatellite data. Our study demonstrates how extensive pollen flow can erase the genetic imprint of long-term refugial isolation in maternal lineages, effectively preventing population differentiation in temperate, particularly wind-pollinated, forest trees in subtropical China.

  4. Calcium in pollen-pistil interaction in `Petunia hybrida Hor`. Pt. 1. Localization of Ca{sup 2+} ions in mature pollen grain using pyroantimonate and autoradiographic methods

    Energy Technology Data Exchange (ETDEWEB)

    Bednarska, E.; Butowt, R. [Uniwersytet Mikolaja Kopernika, Torun (Poland)

    1994-12-31

    The localization of Ca{sup 2+} in the mature pollen grain and the flow of these ions the somatic tissues of the anther to the pollen grains has been studied using pyroantimonate and autoradiographic methods. In the pollen grain, Ca{sup 2+} ions have been localized in the sporoderm in the cytoplasmic vesicles of probably dictyosomal origin. Calcium ions were transported into the sporoderm together with the compounds of degenerating tapetum. The material of degenerating tapetum forms pollen coat surrounding the mature pollen grains. (author). 18 refs, 9 figs.

  5. Influence of boundary-layer dynamics on pollen dispersion and viability

    Science.gov (United States)

    Arritt, Raymond W.; Viner, Brian J.; Westgate, Mark E.

    2013-04-01

    Adoption of genetically modified (GM) crops has raised concerns that GM traits can accidentally cross into conventional crops or wild relatives through the transport of wind-borne pollen. In order to evaluate this risk it is necessary to account both for dispersion of the pollen grains and environmental influences on pollen viability. The Lagrangian approach is suited to this problem because it allows tracking the environmental temperature and moisture that pollen grains experience as they travel. Taking advantage of this capability we have combined a high-resolution version of the WRF meteorological model with a Lagrangian particle dispersion model to predict maize pollen dispersion and viability. WRF is used to obtain fields of wind, turbulence kinetic energy, temperature, and humidity which are then used as input to the Lagrangian dispersion model. The dispersion model in turn predicts transport of a statistical sample of a pollen cloud from source plants to receptors. We also use the three-dimensional temperature and moisture fields from WRF to diagnose changes in moisture content of the pollen grains and consequent loss of viability. Results show that turbulent motions in the convective boundary layer counteract the large terminal velocity of maize pollen grains and lift them to heights of several hundred meters, so that they can be transported long distances before settling to the ground. We also found that pollen lifted into the upper part of the boundary layer remains more viable than has been inferred using surface observations of temperature and humidity. This is attributed to the thermal and moisture structure that typifies the daytime atmospheric boundary layer, producing an environment of low vapor pressure deficit in the upper boundary layer which helps maintain pollen viability.

  6. Phylogenetic evidence of long distance dispersal and transmission of piscine reovirus (PRV between farmed and wild Atlantic salmon.

    Directory of Open Access Journals (Sweden)

    Åse Helen Garseth

    Full Text Available The extent and effect of disease interaction and pathogen exchange between wild and farmed fish populations is an ongoing debate and an area of research that is difficult to explore. The objective of this study was to investigate pathogen transmission between farmed and wild Atlantic salmon (Salmo salar L. populations in Norway by means of molecular epidemiology. Piscine reovirus (PRV was selected as the model organism as it is widely distributed in both farmed and wild Atlantic salmon in Norway, and because infection not necessarily will lead to mortality through development of disease. A matrix comprised of PRV protein coding sequences S1, S2 and S4 from wild, hatchery-reared and farmed Atlantic salmon in addition to one sea-trout (Salmo trutta L. was examined. Phylogenetic analyses based on maximum likelihood and Bayesian inference indicate long distance transport of PRV and exchange of virus between populations. The results are discussed in the context of Atlantic salmon ecology and the structure of the Norwegian salmon industry. We conclude that the lack of a geographical pattern in the phylogenetic trees is caused by extensive exchange of PRV. In addition, the detailed topography of the trees indicates long distance transportation of PRV. Through its size, structure and infection status, the Atlantic salmon farming industry has the capacity to play a central role in both long distance transportation and transmission of pathogens. Despite extensive migration, wild salmon probably play a minor role as they are fewer in numbers, appear at lower densities and are less likely to be infected. An open question is the relationship between the PRV sequences found in marine fish and those originating from salmon.

  7. Landscape epidemiology and control of pathogens with cryptic and long-distance dispersal: sudden oak death in northern Californian forests.

    Directory of Open Access Journals (Sweden)

    João A N Filipe

    2012-01-01

    Full Text Available Exotic pathogens and pests threaten ecosystem service, biodiversity, and crop security globally. If an invasive agent can disperse asymptomatically over long distances, multiple spatial and temporal scales interplay, making identification of effective strategies to regulate, monitor, and control disease extremely difficult. The management of outbreaks is also challenged by limited data on the actual area infested and the dynamics of spatial spread, due to financial, technological, or social constraints. We examine principles of landscape epidemiology important in designing policy to prevent or slow invasion by such organisms, and use Phytophthora ramorum, the cause of sudden oak death, to illustrate how shortfalls in their understanding can render management applications inappropriate. This pathogen has invaded forests in coastal California, USA, and an isolated but fast-growing epidemic focus in northern California (Humboldt County has the potential for extensive spread. The risk of spread is enhanced by the pathogen's generalist nature and survival. Additionally, the extent of cryptic infection is unknown due to limited surveying resources and access to private land. Here, we use an epidemiological model for transmission in heterogeneous landscapes and Bayesian Markov-chain-Monte-Carlo inference to estimate dispersal and life-cycle parameters of P. ramorum and forecast the distribution of infection and speed of the epidemic front in Humboldt County. We assess the viability of management options for containing the pathogen's northern spread and local impacts. Implementing a stand-alone host-free "barrier" had limited efficacy due to long-distance dispersal, but combining curative with preventive treatments ahead of the front reduced local damage and contained spread. While the large size of this focus makes effective control expensive, early synchronous treatment in newly-identified disease foci should be more cost-effective. We show how the

  8. 天然气长输管道计量系统设计%Design of Metering System in Long-Distance Natural Gas Transportation Pipeline

    Institute of Scientific and Technical Information of China (English)

    刘朋

    2016-01-01

    计量系统是天然气长输管道中的重要组成部分,介绍了长输管道计量系统中常用流量计特点,给出了计量系统仪表选型及设计的一般过程,详细说明了精度考虑、口径考虑、流速计算及回路配置等问题的设计原则及计算方法。给出了以气体超声流量计、在线气体色谱分析仪、流量计算机等构建的体积流量和能量流量的计量系统的典型配置。%Flow measurement system is an important component in long-distance natural gas transportation pipe; flowmeters usually used in gas metering are introduced and compared in this paper. Meter selection and general design procedure are also given out including accuracy consideration,diameter consideration,velocity calculation,loop configration,etc.A typical metering system based on ultrasonic meter,online chromatographic analyzer,flow computer is constructed.

  9. Long-distance pulse propagation on high-frequency dissipative nonlinear transmission lines/resonant tunneling diode line cascaded maps

    Energy Technology Data Exchange (ETDEWEB)

    Klofai, Yerima [Department of Physics, Higher Teacher Training College, University of Maroua, PO Box 46 Maroua (Cameroon); Essimbi, B Z [Department of Physics, Faculty of Science, University of Yaounde 1, PO Box 812 Yaounde (Cameroon); Jaeger, D, E-mail: bessimb@yahoo.fr [ZHO, Optoelectronik, Universitaet Duisburg-Essen, D-47048 Duisburg (Germany)

    2011-10-15

    Pulse propagation on high-frequency dissipative nonlinear transmission lines (NLTLs)/resonant tunneling diode line cascaded maps is investigated for long-distance propagation of short pulses. Applying perturbative analysis, we show that the dynamics of each line is reduced to an expanded Korteweg-de Vries-Burgers equation. Moreover, it is found by computer experiments that the soliton developed in NLTLs experiences an exponential amplitude decay on the one hand and an exponential amplitude growth on the other. As a result, the behavior of a pulse in special electrical networks made of concatenated pieces of lines is closely similar to the transmission of information in optical/electrical communication systems.

  10. Long distance movements and disjunct spatial use of harbor seals (Phoca vitulina in the inland waters of the Pacific Northwest.

    Directory of Open Access Journals (Sweden)

    Sarah H Peterson

    Full Text Available BACKGROUND: Worldwide, adult harbor seals (Phoca vitulina typically limit their movements and activity to 100 km from their capture site at least once, two of which traveled round trip to and from the Pacific coast, a total distance >400 km. Disjunct spatial use patterns observed provide new insight into general harbor seal behavior. CONCLUSIONS/SIGNIFICANCE: Long-distance movements and disjunct spatial use of adult harbor seals have not been reported for the study region and are rare worldwide in such a large proportion of tagged individuals. Thus, the ecological influence of individual seals may reach farther than previously assumed.

  11. Rodent middens reveal episodic, long-distance plant colonizations across the hyperarid Atacama Desert over the last 34,000 years

    Science.gov (United States)

    Diaz, Francisca P.; Latorre, Claudio; Maldonado, Antonio; Quade, Jay; Betancourt, Julio L.

    2012-01-01

    Aim To document the impact of late Quaternary pluvial events on plant movements between the coast and the Andes across the Atacama Desert, northern Chile. Location Sites are located along the lower and upper fringes of absolute desert (1100–2800 m a.s.l.), between the western slope of the Andes and the Coastal Ranges of northern Chile (24–26° S). Methods We collected and individually radiocarbon dated 21 rodent middens. Plant macrofossils (fruits, seeds, flowers and leaves) were identified and pollen content analysed. Midden assemblages afford brief snapshots of local plant communities that existed within the rodents' limited foraging range during the several years to decades that it took the midden to accumulate. These assemblages were then compared with modern floras to determine the presence of extralocal species and species provenance. Results Five middens span the last glacial period (34–21 ka) and three middens are from the last glacial–interglacial transition (19–11 ka). The remaining 13 middens span the last 7000 years. Coastal hyperarid sites exhibit low taxonomic richness in middens at 19.3, 1.1, 1.0, 0.9, 0.5 ka and a modern sample. Middens are also dominated by the same plants that occur today. In contrast, middens dated to 28.1, 21.3, 17.3, 3.7 and 0.5 ka contain more species, including Andean extralocals. Precordillera middens (c. 2700 m) show a prominent increase in plant macrofossil richness, along with the appearance of Andean extralocals and sedges at 34.5 and 18.9 ka. Six younger middens dated to 6.1–0.1 ka are similar to the modern local vegetation. Main conclusions Increased species richness and Andean extralocal plants occurred along the current lower fringes of absolute desert during the last glacial–interglacial transition and late Holocene. The absence of soil carbonates indicates the persistence of absolute desert throughout the Quaternary. Colonization by Andean plants could have been accomplished through long-distance seed

  12. Decreased sensitivity to long-distance dependencies in children with a history of specific language impairment: electrophysiological evidence.

    Science.gov (United States)

    Purdy, J D; Leonard, Laurence B; Weber-Fox, Christine; Kaganovich, Natalya

    2014-06-01

    One possible source of tense and agreement limitations in children with specific language impairment (SLI) is a weakness in appreciating structural dependencies that occur in many sentences in the input. This possibility was tested in the present study. Children with a history of SLI (H-SLI; n = 12; M = 9;7 [years;months]) and typically developing same-age peers (TD; n = 12; M = 9;7) listened to and made grammaticality judgments about grammatical and ungrammatical sentences involving either a local agreement error (e.g., "Every night they talks on the phone") or a long-distance finiteness error (e.g., "He makes the quiet boy talks a little louder"). Electrophysiological (ERP) and behavioral (accuracy) measures were obtained. Local agreement errors elicited the expected anterior negativity and P600 components in both groups of children. However, relative to the TD group, the P600 effect for the long-distance finiteness errors was delayed, reduced in amplitude, and shorter in duration for the H-SLI group. The children's grammaticality judgments were consistent with the ERP findings. Children with H-SLI seem to be relatively insensitive to the finiteness constraints that matrix verbs place on subject-verb clauses that appear later in the sentence.

  13. Phylogenetics of the Chamaesyce clade (Euphorbia, Euphorbiaceae): reticulate evolution and long-distance dispersal in a prominent C4 lineage.

    Science.gov (United States)

    Yang, Ya; Berry, Paul E

    2011-09-01

    The Chamaesyce clade of Euphorbia is the largest lineage of C(4) plants among the eudicots, with 350 species including both narrow endemics and cosmopolitan weeds. We sampled this group worldwide to address questions about subclade relationships, the origin of C(4) photosynthesis, the evolution of weeds, and the role of hybridization and long-distance dispersal in the diversification of the group. • Two nuclear (ITS and exon 9 of EMB2765) and three chloroplast markers (matK, rpl16, and trnL-F) were sequenced for 138 ingroup and six outgroup species. Exon 9 of EMB2765 was cloned in accessions with >1% superimposed peaks. • The Chamaesyce clade is monophyletic and consists of three major subclades [1(2,3)]: (1) the Acuta clade, containing three North American species with C(3) photosynthesis and C(3)-C(4) intermediates; (2) the Peplis clade, mostly North American and entirely C(4); and (3) the Hypericifolia clade, all C(4), with both New World and Old World groups. Incongruence between chloroplast and ITS phylogenies and divergent cloned copies of EMB2765 exon 9 suggest extensive hybridization, especially in the Hawaiian Islands radiation. • The Chamaesyce clade originated in warm, arid areas of North America, where it evolved C(4) photosynthesis. From there, it diversified globally with extensive reticulate evolution and frequent long-distance dispersals. Although many species are weedy, there are numerous local adaptations to specific substrates and regional or island radiations, which have contributed to the great diversity of this group.

  14. Time-Varying Hydraulic Gradient Model of Paste-Like Tailings in Long-Distance Pipeline Transportation

    Directory of Open Access Journals (Sweden)

    Li Yang

    2017-01-01

    Full Text Available Paste-like tailings slurry (PTLS is always simplified as a Bingham plastic fluid, leading to excessive computational errors in the calculation of the hydraulic gradient. In the case of paste-like tailings in long-distance pipeline transportation, to explore a high-precision and reliable hydraulic gradient formula, the rheological behavior of paste-like tailings slurry was analyzed, a time-varying hydraulic gradient model was constructed, and a series of laboratory shear tests were conducted. The results indicate that the PTLS shows noticeable shear-thinning characteristics in constant shear tests; the calculated hydraulic gradient declined by about 56%, from 4.44 MPa·km−1 to 1.95 MPa·km−1 within 253 s, and remained constant for the next four hours during the pipeline transportation. Comparing with the balance hydraulic gradient obtained in a semi-industrial loop test, the computational errors of those calculated by using the time-varying hydraulic gradient model, Jinchuan formula, and Shanxi formula are 15%, 78%, and 130%, respectively. Therefore, our model is a feasible and high-precision solution for the calculation of the hydraulic gradient of paste-like tailings in long-distance pipeline transportation.

  15. Frauengerechte Weiterbildung in Fernlehrgängen Just Further Education for Women in Long-Distance Learning Courses

    Directory of Open Access Journals (Sweden)

    Cornelia Carstens

    2004-07-01

    Full Text Available Gisela Pravda untersucht in ihrer 2002 an der Humboldt Universität Berlin vorgelegten Dissertation berufsbildende Fernlehrgänge in Deutschland aus feministischer Perspektive. Sie richtet ihren Blick auf die dort verwendeten Unterrichtsmaterialien und analysiert Sprache und Inhalt daraufhin, inwieweit traditionelle Geschlechterrollen reproduziert und Frauen damit als Lernende behindert oder ausgeschlossen werden. Ihr Befund ist deprimierend: Auch an der Wende vom 20. zum 21. Jahrhundert orientieren sich Sprache und Inhalt im Fernlernen an traditionellen androzentrischen Mustern, werden jahrzehntelange Frauenbewegung und -forschung ignoriert. Pravda bleibt bei der Analyse nicht stehen, sondern entwickelt konkrete Checklisten, mit deren Hilfe Lernmaterialien gendergerecht umgestaltet werden können.In her dissertation presented at the Humboldt University Berlin in 2002, Gisela Pravda examines occupational long-distance learning courses in Germany from a feminist perspective. She considers the applied learning materials and analyzes to what extent the language and content reproduce traditional gender roles and, with this, the extent to which women are hindered or excluded as learners. Her results are depressing: Also at the turn of the 20th to 21st century, the language and content of long-distance learning are oriented toward traditional androcentric patterns, and the women’s movement and women’s studies of the last decades are ignored. Pravda not only offers analyses, but also develops concrete check lists that can be used to restructure learning material to adequately include gender.

  16. Extreme long-distance dispersal of the lowland tropical rainforest tree Ceiba pentandra L. (Malvaceae) in Africa and the Neotropics.

    Science.gov (United States)

    Dick, Christopher W; Bermingham, Eldredge; Lemes, Maristerra R; Gribel, Rogerio

    2007-07-01

    Many tropical tree species occupy continental expanses of rainforest and flank dispersal barriers such as oceans and mountains. The role of long-distance dispersal in establishing the range of such species is poorly understood. In this study, we test vicariance hypotheses for range disjunctions in the rainforest tree Ceiba pentandra, which is naturally widespread across equatorial Africa and the Neotropics. Approximate molecular clocks were applied to nuclear ribosomal [ITS (internal transcribed spacer)] and chloroplast (psbB-psbF) spacer DNA sampled from 12 Neotropical and five West African populations. The ITS (N=5) and psbB-psbF (N=2) haplotypes exhibited few nucleotide differences, and ITS and psbB-psbF haplotypes were shared by populations on both continents. The low levels of nucleotide divergence falsify vicariance explanations for transatlantic and cross-Andean range disjunctions. The study shows how extreme long-distance dispersal, via wind or marine currents, creates taxonomic similarities in the plant communities of Africa and the Neotropics.

  17. Long-distance multi-channel bidirectional chaos communication based on synchronized VCSELs subject to chaotic signal injection

    Science.gov (United States)

    Xie, Yi-Yuan; Li, Jia-Chao; He, Chao; Zhang, Zhen-Dong; Song, Ting-Ting; Xu, Chang-Jun; Wang, Gui-Jin

    2016-10-01

    A novel long-distance multi-channel bidirectional chaos communication system over multiple paths based on two synchronized 1550 nm vertical-cavity surface-emitting lasers (VCSELs) is proposed and studied theoretically. These two responding VCSELs (R-VCSELs) can output similar chaotic signals served as chaotic carrier in two linear polarization (LP) modes with identical signal injection from a driving VCSEL (D-VCSEL), which is subject to optical feedback and optical injection, simultaneously. Through the numerical simulations, high quality chaos synchronization between the two R-VCSELs can be obtained. Besides, the effects of varied qualities of chaos synchronization on communication performances in 20 km single mode fiber (SMF) channels are investigated by regulating different internal parameters mismatch after adopting chaos masking (CMS) technique. With the decrease of the maximum cross correlation coefficient (Max-C) between the two R-VCSELs, the bit error rate (BER) of decoded message increase. Meanwhile, the BER can still be less than 10-9 when the Max-C degrades to 0.982. Based on high quality synchronization, when the dispersion compensating fiber (DCF) links are introduced, 4n messages of 10 Gbit/s can transmit in 180 km SMF channels over n coupling paths, bidirectionally and simultaneously. Thorough tests are carried out with detailed analysis, demonstrating long-distance, multi-channel, bidirectional chaos communication based on VCSELs with chaotic signal injection.

  18. Acoustic Repertoire of the Philippine Tarsier (Tarsius syrichta fraterculus and Individual Variation of Long-Distance Calls

    Directory of Open Access Journals (Sweden)

    Milada Řeháková-Petrů

    2012-01-01

    Full Text Available We present the spectrographic description of the vocal repertoire of the Philippine tarsier (Tarsius syrichta fraterculus, a solitary living nocturnal primate for which a very limited information about acoustic communication exists to date. The majority of vocalizations were performed around sunset and, less frequently, at sunrise. We identified eight call types. Five calls recorded during communication between adults included three long-distance calls—loud call, smack-whistle, and whistle—then a soft locust-like chirp and a bird-like trill. Two other calls—cheep and twitter—were recorded during mother-infant communication. One distress call was emitted by adults during handling. All calls were performed in the 9752 Hz to more than 22 kHz frequency range. This study provides the first evidence of individual variation in the long-distance calls performed by tarsiers. Moreover, our study provides a basis for future comparison within as well as between tarsier species taxonomy. Bioacoustic methods can be used in monitoring of these cryptic species and determining their distribution range. Thus, bioacoustic studies can help to improve conservation strategies of different population/species.

  19. Elevated Serum Hepcidin Levels during an Intensified Training Period in Well-Trained Female Long-Distance Runners

    Directory of Open Access Journals (Sweden)

    Aya Ishibashi

    2017-03-01

    Full Text Available Iron is essential for providing oxygen to working muscles during exercise, and iron deficiency leads to decreased exercise capacity during endurance events. However, the mechanism of iron deficiency among endurance athletes remains unclear. In this study, we compared iron status between two periods involving different training regimens. Sixteen female long-distance runners participated. Over a seven-month period, fasting blood samples were collected during their regular training period (LOW; middle of February and during an intensified training period (INT; late of August to determine blood hematological, iron, and inflammatory parameters. Three-day food diaries were also assessed. Body weight and lean body mass did not differ significantly between LOW and INT, while body fat and body fat percentage were significantly lower in INT (p < 0.05. Blood hemoglobin, serum ferritin, total protein, and iron levels, total iron-binding capacity, and transferrin saturation did not differ significantly between the two periods. Serum hepcidin levels were significantly higher during INT than LOW (p < 0.05. Carbohydrate and iron intakes from the daily diet were significantly higher during INT than LOW (p < 0.05. In conclusion, an elevated hepcidin level was observed during an intensified training period in long-distance runners, despite an apparently adequate daily intake of iron.

  20. Insights into antimicrobial resistance among long distance migratory East Canadian High Arctic light-bellied Brent geese (Branta bernicla hrota).

    Science.gov (United States)

    Agnew, Austin; Wang, Juan; Fanning, Séamus; Bearhop, Stuart; McMahon, Barry J

    2015-01-01

    Antimicrobial resistance (AMR) is the most significant threat to global public health and ascertaining the role wild birds play in the epidemiology of resistance is critically important. This study investigated the prevalence of AMR Gram-negative bacteria among long-distance migratory East Canadian High Arctic (ECHA) light-bellied Brent geese found wintering on the east coast of Ireland. In this study a number of bacterial species were isolated from cloacal swabs taken from ECHA light-bellied Brent geese. Nucleotide sequence analysis identified five species of Gram-negative bacteria; the dominant isolated species were Pantoea spp. (n = 5) followed by Buttiauxella agrestis (n = 2). Antimicrobial susceptibility disk diffusion results identified four of the Pantoea spp. strains, and one of the Buttiauxella agrestis strains resistant to amoxicillin-clavulanic acid. To our knowledge this is the first record of AMR bacteria isolated from long distance migratory ECHA light-bellied Brent geese. This indicates that this species may act as reservoirs and potential disseminators of resistance genes into remote natural ecosystems across their migratory range. This population of geese frequently forage (and defecate) on public amenity areas during the winter months presenting a potential human health risk.

  1. Elevated Serum Hepcidin Levels during an Intensified Training Period in Well-Trained Female Long-Distance Runners

    Science.gov (United States)

    Ishibashi, Aya; Maeda, Naho; Sumi, Daichi; Goto, Kazushige

    2017-01-01

    Iron is essential for providing oxygen to working muscles during exercise, and iron deficiency leads to decreased exercise capacity during endurance events. However, the mechanism of iron deficiency among endurance athletes remains unclear. In this study, we compared iron status between two periods involving different training regimens. Sixteen female long-distance runners participated. Over a seven-month period, fasting blood samples were collected during their regular training period (LOW; middle of February) and during an intensified training period (INT; late of August) to determine blood hematological, iron, and inflammatory parameters. Three-day food diaries were also assessed. Body weight and lean body mass did not differ significantly between LOW and INT, while body fat and body fat percentage were significantly lower in INT (p < 0.05). Blood hemoglobin, serum ferritin, total protein, and iron levels, total iron-binding capacity, and transferrin saturation did not differ significantly between the two periods. Serum hepcidin levels were significantly higher during INT than LOW (p < 0.05). Carbohydrate and iron intakes from the daily diet were significantly higher during INT than LOW (p < 0.05). In conclusion, an elevated hepcidin level was observed during an intensified training period in long-distance runners, despite an apparently adequate daily intake of iron. PMID:28335426

  2. Patterns of spread in biological invasions dominated by long-distance jump dispersal: Insights from Argentine ants

    Science.gov (United States)

    Suarez, Andrew V.; Holway, David A.; Case, Ted J.

    2001-01-01

    Invading organisms may spread through local movements (giving rise to a diffusion-like process) and by long-distance jumps, which are often human-mediated. The local spread of invading organisms has been fit with varying success to models that couple local population growth with diffusive spread, but to date no quantitative estimates exist for the relative importance of local dispersal relative to human-mediated long-distance jumps. Using a combination of literature review, museum records, and personal surveys, we reconstruct the invasion history of the Argentine ant (Linepithema humile), a widespread invasive species, at three spatial scales. Although the inherent dispersal abilities of Argentine ants are limited, in the last century, human-mediated dispersal has resulted in the establishment of this species on six continents and on many oceanic islands. Human-mediated jump dispersal has also been the primary mode of spread at a continental scale within the United States. The spread of the Argentine ant involves two discrete modes. Maximum distances spread by colonies undergoing budding reproduction averaged 150 m/year, whereas annual jump-dispersal distances averaged three orders of magnitude higher. Invasions that involve multiple dispersal processes, such as those documented here, are undoubtedly common. Detailed data on invasion dynamics are necessary to improve the predictive power of future modeling efforts. PMID:11158600

  3. First exploratory calculation of the long-distance contributions to the rare kaon decays $K\\to\\pi\\ell^+\\ell^-$

    CERN Document Server

    Christ, Norman H; Juttner, Andreas; Lawson, Andrew; Portelli, Antonin; Sachrajda, Christopher T

    2016-01-01

    The rare decays of a kaon into a pion and a charged lepton/antilepton pair proceed via a flavour changing neutral current and therefore may only be induced beyond tree level in the Standard Model. This natural suppression makes these decays sensitive to the effects of potential New Physics. The CP conserving $K\\to\\pi \\ell^+\\ell^-$ decay channels however are dominated by a single photon exchange; this involves a sizeable long-distance hadronic contribution which represents the current major source of theoretical uncertainty. Here we outline our methodology for the computation of the long-distance contributions to these rare decay amplitudes using lattice QCD and present the numerical results of the first exploratory studies of these decays in which all but the disconnected diagrams are evaluated. The domain wall fermion ensembles of the RBC and UKQCD collaborations are used, with a pion mass of $M_{\\pi}\\sim 430\\,\\mathrm{MeV}$ and a kaon mass of $M_{K}\\sim 625\\,\\mathrm{MeV}$. In particular we determine the form...

  4. Trace-metal concentrations in African dust: effects of long-distance transport and implications for human health

    Science.gov (United States)

    Garrison, Virginia; Lamothe, Paul; Morman, Suzette; Plumlee, Geoffrey S.; Gilkes, Robert; Prakongkep, Nattaporn

    2010-01-01

    The Sahara and Sahel lose billions of tons of eroded mineral soils annually to the Americas and Caribbean, Europe and Asia via atmospheric transport. African dust was collected from a dust source region (Mali, West Africa) and from downwind sites in the Caribbean [Trinidad-Tobago (TT) and U.S. Virgin Islands (VI)] and analysed for 32 trace-elements. Elemental composition of African dust samples was similar to that of average upper continental crust (UCC), with some enrichment or depletion of specific trace-elements. Pb enrichment was observed only in dust and dry deposition samples from the source region and was most likely from local use of leaded gasoline. Dust particles transported long-distances (VI and TT) exhibited increased enrichment of Mo and minor depletion of other elements relative to source region samples. This suggests that processes occurring during long-distance transport of dust produce enrichment/depletion of specific elements. Bioaccessibility of trace-metals in samples was tested in simulated human fluids (gastric and lung) and was found to be greater in downwind than source region samples, for some metals (e.g., As). The large surface to volume ratio of the dust particles (<2.5 µm) at downwind sites may be a factor.

  5. Incidence of chronic knee lesions in long-distance runners based on training level: Findings at MRI

    Energy Technology Data Exchange (ETDEWEB)

    Schueller-Weidekamm, Claudia [Department of Radiology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria)]. E-mail: claudia.schueller-weidekamm@meduniwien.ac.at; Schueller, Gerd [Department of Radiology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Uffmann, Martin [Department of Radiology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Bader, Till [Department of Radiology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria)

    2006-05-15

    Purpose: The purpose of this study was to evaluate the incidence of chronic knee changes in long-distance runners based on the training status, including distance, running frequency, training pace, and running experience. Methods: MRI of the knee was performed in 26 non-professional runners 5 days after their last training unit. Lesions of the menisci and cartilage (5-point scale), bone marrow and ligaments (3-point scale), and joint effusion were evaluated. A total score comprising all knee lesions in each runner was evaluated. The incidence of the knee changes was correlated with the training level, gender, and age of the runners. Results: Grade 1 lesions of the menisci were found in six runners with a high training level, and in only four runners with a low training level. Grade 1 cartilage lesions were found in three high-trained runners and in one low-trained runner, and grade 2 lesions were found in one high-trained runner and in two low-trained runners, respectively. Grade 1 anterior cruciate ligament lesions were seen in three runners with a high- and in two runners with a low-training level. Runners with a higher training level showed a statistically significant higher score for all chronic knee lesions than those with a lower training level (p < 0.05). Conclusions: MRI findings indicate that a higher training level in long-distance runners is a risk factor for chronic knee lesions.

  6. Cytoskeleton in Pollen and Pollen Tubes of Ginkgo biloba L.

    Institute of Scientific and Technical Information of China (English)

    Jun-Mei LIU; Hong ZHANG; Yan LI

    2005-01-01

    The distribution of F-actin and microtubules was investigated in pollen and pollen tubes of Ginkgo biloba L. using a confocal laser scanning microscope after fluorescence and immunofluorescence labeling. A dense F-actin network was found in hydrated Ginkgo pollen. When Ginkgo pollen was germinating,F-actin mesh was found under the plasma membrane from which the pollen tube would emerge. After pollen germination, F-actin bundles were distributed axially in long pollen tubes of G. biloba. Thick F-actin bundles and network were found in the tip of the Ginkgo pollen tube, which is opposite to the results reported for the pollen tubes of some angiosperms and conifers. In addition, a few circular F-actin bundles were found in Ginkgo pollen tubes. Using immunofluorescence labeling, a dense microtubule network was found in hydrated Ginkgo pollen under confocal microscope. In the Ginkgo pollen tube, the microtubules were distributed along the longitudinal axis and extended to the tip. These results suggest that the cytoskeleton may have an essential role in the germination of Ginkgo pollen and tube growth.

  7. Long distance linkage disequilibrium and limited hybridization suggest cryptic speciation in atlantic cod.

    Directory of Open Access Journals (Sweden)

    Ian R Bradbury

    Full Text Available Hybrid zones provide unprecedented opportunity for the study of the evolution of reproductive isolation, and the extent of hybridization across individuals and genomes can illuminate the degree of isolation. We examine patterns of interchromosomal linkage disequilibrium (ILD and the presence of hybridization in Atlantic cod, Gadus morhua, in previously identified hybrid zones in the North Atlantic. Here, previously identified clinal loci were mapped to the cod genome with most (∼70% occurring in or associated with (<5 kb coding regions representing a diverse array of possible functions and pathways. Despite the observation that clinal loci were distributed across three linkage groups, elevated ILD was observed among all groups of clinal loci and strongest in comparisons involving a region of low recombination along linkage group 7. Evidence of ILD supports a hypothesis of divergence hitchhiking transitioning to genome hitchhiking consistent with reproductive isolation. This hypothesis is supported by Bayesian characterization of hybrid classes present and we find evidence of common F1 hybrids in several regions consistent with frequent interbreeding, yet little evidence of F2 or backcrossed individuals. This work suggests that significant barriers to hybridization and introgression exist among these co-occurring groups of cod either through strong selection against hybrid individuals, or genetic incompatibility and intrinsic barriers to hybridization. In either case, the presence of strong clinal trends, and little gene flow despite extensive hybridization supports a hypothesis of reproductive isolation and cryptic speciation in Atlantic cod. Further work is required to test the degree and nature of reproductive isolation in this species.

  8. Long-Distance Travellers: Phylogeography of a Generalist Parasite, Pholeter gastrophilus, from Cetaceans

    Science.gov (United States)

    Lehnert, Kristina; Raga, Juan Antonio; Siebert, Ursula

    2017-01-01

    We studied the phylogeography and historical demography of the most generalist digenean from cetaceans, Pholeter gastrophilus, exploring the effects of isolation by distance, ecological barriers and hosts’ dispersal ability on the population structure of this parasite. The ITS2 rDNA, and the mitochondrial COI and ND1 from 68 individual parasites were analysed. Worms were collected from seven oceanic and coastal cetacean species from the south western Atlantic (SWA), central eastern Atlantic, north eastern Atlantic (NEA), and Mediterranean Sea. Pholeter gastrophilus was considered a single lineage because reciprocal monophyly was not detected in the ML cladogram of all individuals, and sequence variability was cetaceans, with a putative secondary role, if any, of intermediate hosts. Unique haplotypes were detected in SWA and NEA, and an AMOVA revealed significant population structure associated to the genetic variation in these regions. The Equator possibly acts as a significant geographical barrier for cetacean movements, possibly limiting gene flow between northern and southern populations of P. gastrophilus. A partial Mantel tests revealed that the significant isolation of NEA populations resulted from geographic clustering. Apparently, the limited mobility of cetaceans used by P. gastrophilus as definitive hosts in this region, coupled with oceanographic barriers and a patchy distribution of potential intermediate hosts could contribute to significant ecological isolation of P. gastrophilus in NEA. Rather unexpectedly, no genetic differentiation was found in the Mediterranean samples of this parasite. Historical demographic analyses suggested a recent population expansion of P. gastrophilus in the Atlantic Ocean, perhaps linked to initial association and subsequent spreading in cetaceans. PMID:28085945

  9. Migrating songbirds on stopover prepare for, and recover from, oxidative challenges posed by long-distance flight.

    Science.gov (United States)

    Skrip, Megan M; Bauchinger, Ulf; Goymann, Wolfgang; Fusani, Leonida; Cardinale, Massimiliano; Alan, Rebecca R; McWilliams, Scott R

    2015-08-01

    Managing oxidative stress is an important physiological function for all aerobic organisms, particularly during periods of prolonged high metabolic activity, such as long-distance migration across ecological barriers. However, no previous study has investigated the oxidative status of birds at different stages of migration and whether that oxidative status depends on the condition of the birds. In this study, we compared (1) energy stores and circulating oxidative status measures in (a) two species of Neotropical migrants with differing migration strategies that were sampled at an autumn stopover site before an ecological barrier; and (b) a species of trans-Saharan migrant sampled at a spring stopover site after crossing an ecological barrier; and (2) circulating oxidative measures and indicators of fat metabolism in a trans-Saharan migrant after stopovers of varying duration (0-8 nights), based on recapture records. We found fat stores to be positively correlated with circulating antioxidant capacity in Blackpoll Warblers and Red-eyed Vireos preparing for fall migration on Block Island, USA, but uncorrelated in Garden Warblers on the island of Ponza, Italy, after a spring crossing of the Sahara Desert and Mediterranean Sea. In all circumstances, fat stores were positively correlated with circulating lipid oxidation levels. Among Garden Warblers on the island of Ponza, fat anabolism increased with stopover duration while oxidative damage levels decreased. Our study provides evidence that birds build antioxidant capacity as they build fat stores at stopover sites before long flights, but does not support the idea that antioxidant stores remain elevated in birds with high fuel levels after an ecological barrier. Our results further suggest that lipid oxidation may be an inescapable hazard of using fats as the primary fuel for flight. Yet, we also show that birds on stopover are capable of recovering from the oxidative damage they have accrued during migration, as

  10. Migrating songbirds on stopover prepare for, and recover from, oxidative challenges posed by long-distance flight

    Science.gov (United States)

    Skrip, Megan M; Bauchinger, Ulf; Goymann, Wolfgang; Fusani, Leonida; Cardinale, Massimiliano; Alan, Rebecca R; McWilliams, Scott R

    2015-01-01

    Managing oxidative stress is an important physiological function for all aerobic organisms, particularly during periods of prolonged high metabolic activity, such as long-distance migration across ecological barriers. However, no previous study has investigated the oxidative status of birds at different stages of migration and whether that oxidative status depends on the condition of the birds. In this study, we compared (1) energy stores and circulating oxidative status measures in (a) two species of Neotropical migrants with differing migration strategies that were sampled at an autumn stopover site before an ecological barrier; and (b) a species of trans-Saharan migrant sampled at a spring stopover site after crossing an ecological barrier; and (2) circulating oxidative measures and indicators of fat metabolism in a trans-Saharan migrant after stopovers of varying duration (0–8 nights), based on recapture records. We found fat stores to be positively correlated with circulating antioxidant capacity in Blackpoll Warblers and Red-eyed Vireos preparing for fall migration on Block Island, USA, but uncorrelated in Garden Warblers on the island of Ponza, Italy, after a spring crossing of the Sahara Desert and Mediterranean Sea. In all circumstances, fat stores were positively correlated with circulating lipid oxidation levels. Among Garden Warblers on the island of Ponza, fat anabolism increased with stopover duration while oxidative damage levels decreased. Our study provides evidence that birds build antioxidant capacity as they build fat stores at stopover sites before long flights, but does not support the idea that antioxidant stores remain elevated in birds with high fuel levels after an ecological barrier. Our results further suggest that lipid oxidation may be an inescapable hazard of using fats as the primary fuel for flight. Yet, we also show that birds on stopover are capable of recovering from the oxidative damage they have accrued during migration, as

  11. Inter-and intraspecific variation in fern mating systems after long-distance colonization: the importance of selfing

    Directory of Open Access Journals (Sweden)

    de Groot G Arjen

    2012-01-01

    Full Text Available Abstract Background Previous studies on the reproductive biology of ferns showed that mating strategies vary among species, and that polyploid species often show higher capacity for self-fertilization than diploid species. However, the amount of intraspecific variation in mating strategy and selfing capacity has only been assessed for a few species. Yet, such variation may have important consequences during colonization, as the establishment of any selfing genotypes may be favoured after long-distance dispersal (an idea known as Baker's law. Results We examined intra-and interspecific variation in potential for self-fertilization among four rare fern species, of which two were diploids and two were tetraploids: Asplenium scolopendrium (2n, Asplenium trichomanes subsp. quadrivalens (4n, Polystichum setiferum (2n and Polystichum aculeatum (4n. Sporophyte production was tested at different levels of inbreeding, by culturing gametophytes in isolation, as well as in paired cultures with a genetically different gametophyte. We tested gametophytes derived from various genetically different sporophytes from populations in a recently planted forest colonized through long-distance dispersal (Kuinderbos, the Netherlands, as well as from older, less disjunct populations. Sporophyte production in isolation was high for Kuinderbos genotypes of all four species. Selfing capacity did not differ significantly between diploids and polyploids, nor between species in general. Rather selfing capacity differed between genotypes within species. Intraspecific variation in mating system was found in all four species. In two species one genotype from the Kuinderbos showed enhanced sporophyte production in paired cultures. For the other species, including a renowned out crosser, selfing capacity was consistently high. Conclusions Our results for four different species suggest that intraspecific variation in mating system may be common, at least among temperate calcicole

  12. Pollen Viability and Pollen Tube Attrition in Cranberry (Vaccinium macrocarpon)

    Science.gov (United States)

    The content of mature seed in a cranberry fruit increases with stigmatic pollen load. On average, however, only two seeds result for every tetrad of pollen deposited. What then is the fate of the two remaining pollen grains fused in each tetrad? Germination in vitro revealed that most of the grains ...

  13. Extremely low material loss and dispersion flattened TOPAS based circular porous fiber for long distance terahertz wave transmission

    Science.gov (United States)

    Islam, Md. Saiful; Sultana, Jakeya; Rana, Sohel; Islam, Mohammad Rakibul; Faisal, Mohammad; Kaijage, Shubi F.; Abbott, Derek

    2017-03-01

    In this paper, we present a porous-core circular photonic crystal fiber (PC-CPCF) with ultra-low material loss for efficient terahertz wave transmission. The full vector finite element method with an ideally matched layer boundary condition is used to characterize the wave guiding properties of the proposed fiber. At an operating frequency of 1 THz, simulated results exhibit an extremely low effective material loss of 0.043 cm-1, higher core power fraction of 47% and ultra-flattened dispersion variation of 0.09 ps/THz/cm. The effects of important design properties such as single mode operation, confinement loss and effective area of the fiber are investigated in the terahertz regime. Moreover, the proposed fiber can be fabricated using the capillary stacking or sol-gel technique and be useful for long distance transmission of terahertz waves.

  14. Effects of low-dose G-CSF formulation on hematology in healthy horses after long-distance transportation.

    Science.gov (United States)

    Endo, Yoshiro; Hobo, Seiji; Korosue, Kenji; Ootsuka, Kenji; Kitauchi, Akira; Kikkawa, Risa; Hidaka, Yuichi; Hagio, Mitsuyoshi; Tsuzuki, Nao

    2015-04-01

    The present study evaluated the effects of single-dose filgrastim on hematology in 16 healthy horses after long-distance transportation. Horses were assigned to receive filgrastim (0.23 µg/kg, SC, once; G-CSF group; n=8) or saline (0.9% NaCl) solution (0.3 ml, SC, once; control group; n=8) ≤ 1 hr before transportation. Horses were transported 2,530 km using commercial vans over the course of approximately 44 hr. Clinical examinations and hematologic analyses were performed on all horses before and after transportation. Because the post-transportation white blood cell counts and bacillary neutrophil to segmented neutrophil ratio were significantly higher in the G-CSF group, filgrastim may have promoted the mobilization of neutrophils from marrow. Filgrastim deserves a further study for efficacy in preventing horse shipping fever.

  15. Structure and agency in long-distance truck drivers' lived experiences of condom use for HIV prevention.

    Science.gov (United States)

    Sastry, Shaunak

    2016-01-01

    Condom promotion has emerged as a mainstay of targeted HIV prevention interventions in India, with its emphasis on individual behaviour change and personal responsibility. However, such approaches often do not account for marginalised populations' structural vulnerability to HIV, arising from social, economic and political factors in the lived environment. In this paper, I use a critical health communication framework to analyse how structure and agency interact in influencing condom use among long-distance truck drivers in India. Drawing on an abductive discourse analysis of condom-use discourses among truckers and peer educators in two Indian cities, findings reveal that while truckers understand the biomedical logic of condoms as barriers, they also express anxiety about condom breakage and experience structural barriers to condom use. The paper concludes by calling for greater attention to structural vulnerabilities in future HIV prevention efforts with truck drivers.

  16. Long-distance remote comparison of ultrastable optical frequencies with 10(-15) instability in fractions of a second.

    Science.gov (United States)

    Pape, A; Terra, O; Friebe, J; Riedmann, M; Wübbena, T; Rasel, E M; Predehl, K; Legero, T; Lipphardt, B; Schnatz, H; Grosche, G

    2010-09-27

    We demonstrate a fully optical, long-distance remote comparison of independent ultrastable optical frequencies reaching a short term stability that is superior to any reported remote comparison of optical frequencies. We use two ultrastable lasers, which are separated by a geographical distance of more than 50 km, and compare them via a 73 km long phase-stabilized fiber in a commercial telecommunication network. The remote characterization spans more than one optical octave and reaches a fractional frequency instability between the independent ultrastable laser systems of 3 x 10 (-15) in 0.1 s. The achieved performance at 100 ms represents an improvement by one order of magnitude to any previously reported remote comparison of optical frequencies and enables future remote dissemination of the stability of 100 mHz linewidth lasers within seconds.

  17. The use of social networking sites for relationship maintenance in long-distance and geographically close romantic relationships.

    Science.gov (United States)

    Billedo, Cherrie Joy; Kerkhof, Peter; Finkenauer, Catrin

    2015-03-01

    Social networking sites (SNS) play an increasingly important role in maintaining geographically close romantic relationships (GCRR). However, knowledge about SNS use in long-distance romantic relationships (LDRR) is still lacking. The present study examined the relative importance of SNS in maintaining LDRR compared to GCRR, particularly with regard to the use of SNS to express involvement (via relational maintenance behaviors) and to gauge a partner's involvement (via partner surveillance and jealousy) in the relationship. An online survey was conducted among predominantly young adult Facebook users who were in a romantic relationship (N=272). Results showed that participants who were in a LDRR reported higher levels of relational maintenance behaviors through SNS than participants who were in a GCRR. Also, as compared to participants who were in a GCRR, participants who were in a LDRR used SNS more for partner surveillance and experienced higher levels of SNS jealousy.

  18. Long-distance inter-hydrogen bond coupling effects in the polarized IR spectra of succinic acid crystals

    Science.gov (United States)

    Flakus, Henryk T.; Hachuła, Barbara; Hołaj-Krzak, Jakub T.

    2015-05-01

    The spectral properties of four different crystalline succinic acid (HOOC-(CH2)2-COOH) (SAC) isotopomer systems, h6, d2, d4 and d6, were examined by means of the IR spectroscopy in polarized light aided by numerical simulations of the νO-H and νO-D band contour shapes on utilizing the "strong-coupling" model. The abnormal IR spectral properties of SAC crystals in relation to the corresponding properties of glutaric, pimelic and adipic acid crystals were ascribed to the hyperconjugation electronic effects in the acid associated molecules. A vibronic coupling mechanism involving the proton stretching vibrations in the (COOH)2 cycles and the electronic motions in the molecular skeletons, the isotopic "H/D self-organization" mechanisms and a long-distance vibrational exciton coupling between the adjacent (COOH)2 cycles in the molecular chains are mainly responsible for the generation of the temperature effects in the crystalline IR spectra.

  19. 2012 ARPA-E Energy Innovation Summit: Profiling Foro Energy: High Power Lasers - Long Distances (Performer Video)

    Energy Technology Data Exchange (ETDEWEB)

    None Available

    2012-02-28

    The third annual ARPA-E Energy Innovation Summit was held in Washington D.C. in February, 2012. The event brought together key players from across the energy ecosystem - researchers, entrepreneurs, investors, corporate executives, and government officials - to share ideas for developing and deploying the next generation of energy technologies. A few videos were selected for showing during the Summit to attendees. These 'performer videos' highlight innovative research that is ongoing and related to the main topics of the Summit's sessions. Featured in this video from Foro Energy are Joel Moxley, Founder and CEO, Mark Zediker, Founder and CTO, and Paul Deutch, President and COO. Steven Chu, Secretary of Energy, also appears briefly in this video to praise the accomplishment of a high powered laser that can transmit that power long distances for faster and more powerful drilling of geothermal, oil, and gas wells.

  20. Acute changes in muscle activation and leg extension performance after different running exercises in elite long distance runners.

    Science.gov (United States)

    Vuorimaa, Timo; Virlander, Rami; Kurkilahti, Pasi; Vasankari, Tommi; Häkkinen, Keijo

    2006-02-01

    This study investigated acute changes in muscle activation and muscular power performance after three different running exercises in elite long-distance runners. Twenty-two nationally and internationally ranked long-distance runners performed first an incremental treadmill running test until exhaustion (MR) and then 40 min continuous (TR) and intermittent (2 min run/2 min rest) (IR) running exercises at an intensity of 80 and 100% of the velocity associated with VO(2max), respectively. Muscle activation and muscular power performance tests (counter-movement jumps, CMJ, and a set of ten maximal half squats from the static starting position with an extra load of 35% of the subjects, one repetition maximum) were performed before and immediately after the runs. The average mechanical power (P) of the half squats was calculated and the root mean square electromyogram (EMGrms) from the vastus lateralis, vastus medialis, gastrocnemius and biceps femoris muscles was recorded simultaneously during the half squat performances. The results showed an acute exercise-induced increase in P (ANOVA time effect, P = 0.000) together with a reduction in EMGrms of the knee extensor muscles (ANOVA time effect, P = 0.000). However, mechanical P expressed as a relative change within the set decreased after MR. In TR the improvement in P correlated positively with the maximal running performance of the runners (P muscles, and may lead to a different coordination strategy in leg extension exercises performed into the vertical direction. After continuous type of running the power improvement correlates positively with maximal endurance running capacity, whereas after intermittent type of running it correlates negatively.

  1. Pain sensitivity, mood and plasma endocrine levels in man following long-distance running: effects of naloxone.

    Science.gov (United States)

    Janal, M N; Colt, E W; Clark, W C; Glusman, M

    1984-05-01

    The effects of intense exercise on pain perception, mood, and plasma endocrine levels in man were studied under naloxone and saline conditions. Twelve long-distance runners (mean weekly mileage = 41.5) were evaluated on thermal, ischemic, and cold pressor pain tests and on mood visual analogue scales (VAS). Blood was drawn for determination of plasma levels of beta-endorphin-like immunoreactivity (BEir), growth hormone (GH), adrenocorticotrophic hormone (ACTH), and prolactin (PRL). These procedures were undertaken before and after a 6.3 mile run at 85% of maximal aerobic capacity. Subjects participated on two occasions in a double-blind procedure counterbalanced for drug order: on one day they received 2 i.v. injections of naloxone (0.8 mg in 2 ml vehicle each) at 20 min intervals following the run; on the other day, 2 equal volume injections of normal saline (2 ml). Sensory decision theory analysis of the responses to thermal stimulation showed that discriminability, P(A), was significantly reduced post-run under the saline condition, a hypoalgesic effect; response bias, B, was unaffected. Ischemic pain reports were significantly reduced post-run on the saline day, also a hypoalgesic effect. Naloxone reversed the post-run ischemic but not thermal hypoalgesic effects. Joy, euphoria, cooperation, and conscientiousness VAS ratings were elevated post-run; naloxone attenuated the elevation of joy and euphoria ratings only. Plasma levels of BEir, ACTH, GH, and PRL were significantly increased post-run. The results show that long-distance running produces hypoalgesia and mood elevation in man. The effects of naloxone implicate endogenous opioid neural systems as mechanisms of some but not all of the run-induced alterations in mood and pain perception.

  2. Health care coverage among long-distance truckers in India: an evaluation based on the Tanahashi model

    Directory of Open Access Journals (Sweden)

    Sharma V

    2015-03-01

    Full Text Available Varun Sharma,1 Niranjan Saggurti,2 Shalini Bharat11School of Health Systems Studies, Tata Institute of Social Sciences, Mumbai, India; 2HIV AIDS Program, Population Council, New Delhi, IndiaAbstract: Long-distance truckers (LDTDs are vulnerable to human immunodeficiency virus infection and other sexually transmitted infections due to the nature of their work, working environment, and frequent mobility. This paper examines and comments on the health care coverage provisioned under “Kavach” Project. Data from the Integrated Behavioural and Biological Survey, National Highway gathered from 2,066 LDTDs in Round 1 and 2,085 LDTDs in Round 2, who traveled in four extreme road corridors travelled by LDTDs in India, were used for analysis. Analysis reveals that service capacity in terms of socially marketed condoms per thousand LDTDs has increased from Round 1 to Round 2 (4,430 to 6,876, respectively. Accessibility coverage in terms of knowledge about the Khushi clinic has significantly decreased between Rounds 1 and 2 (60.9% to 54.6%; P<0.001. Acceptability coverage has increased between the two rounds (13.8% to 50.6%; P<0.001. Contact coverage has also increased between the rounds (12.7% to 22.3%; P<0.001. Effectiveness coverage for preventive and curative care has also increased significantly. This paper comments on the gaps in accessibility and acceptability of health care coverage and emphasizes the need for further studies to assess the contextual factors that influence the effectiveness and efficiency of interventions designed to address access barriers and to identify what combination of interventions may generate the best possible outcome.Keywords: HIV, long-distance truck drivers, mobility, national highways, Tanahashi framework, India

  3. Heading towards the Safer Highways: an assessment of the Avahan prevention programme among long distance truck drivers in India

    Directory of Open Access Journals (Sweden)

    Pandey Arvind

    2011-12-01

    Full Text Available Abstract Background Using data from two rounds of a cross-sectional, national-level survey of long-distance truck drivers, this paper examines the extent and trend of sexual risk behavior, prevalence of STI/HIV, and the linkage between exposure to HIV prevention programs and safe sex behavior. Methods Following the time location cluster sampling approach, major transshipment locations covering the bulk of India’s transport volume along four routes, North-East (NE, North-South (NS, North-West (NW and South-East (SE were surveyed. First round of the survey was conducted in 2007 (sample size 2066 whereas the second round was undertaken in 2009-2010 (sample size 2085. Long distance truck drivers were interviewed about their sexual behaviors, condom use practices, exposure to different HIV prevention interventions, and tested for HIV, reactive syphilis serology, Neiserria gonorrhoeae and Chlamydia trachomatis. The key variable of this evaluation study - exposure to HIV prevention interventions was divided into three categories - no exposure, less intensive exposure and intensive exposure. Data were analyzed using multiple logistic regression methods to understand the relationship between risk behavior and exposure to intervention and between program exposure and condom use. Results The proportion of truckers exposed to HIV prevention interventions has increased over time with much significant increase in the intensive exposure across all the four routes (NE: from 14.9% to 28%, P Conclusions These evaluation study results highlight the ability of intensive program to reach truckers who have sex outside marriage with HIV prevention interventions and promote safe sex behaviors among them. Truckers who practice safe sex behaviors with an exposure to intensive program are less likely to suffer from STIs and HIV, which has implications for HIV prevention program with truckers’ population in India and elsewhere. The simultaneous targeted interventions

  4. Heading towards the Safer Highways: an assessment of the Avahan prevention programme among long distance truck drivers in India.

    Science.gov (United States)

    Pandey, Arvind; Mishra, Ram Manohar; Sahu, Damodar; Benara, Sudhir Kumar; Sengupta, Uttpal; Paranjape, Ramesh S; Gautam, Abhishek; Lenka, Satya Ranjan; Adhikary, Rajatshurva

    2011-12-29

    Using data from two rounds of a cross-sectional, national-level survey of long-distance truck drivers, this paper examines the extent and trend of sexual risk behavior, prevalence of STI/HIV, and the linkage between exposure to HIV prevention programs and safe sex behavior. Following the time location cluster sampling approach, major transshipment locations covering the bulk of India's transport volume along four routes, North-East (NE), North-South (NS), North-West (NW) and South-East (SE) were surveyed. First round of the survey was conducted in 2007 (sample size 2066) whereas the second round was undertaken in 2009-2010 (sample size 2085). Long distance truck drivers were interviewed about their sexual behaviors, condom use practices, exposure to different HIV prevention interventions, and tested for HIV, reactive syphilis serology, Neiserria gonorrhoeae and Chlamydia trachomatis. The key variable of this evaluation study - exposure to HIV prevention interventions was divided into three categories - no exposure, less intensive exposure and intensive exposure. Data were analyzed using multiple logistic regression methods to understand the relationship between risk behavior and exposure to intervention and between program exposure and condom use. The proportion of truckers exposed to HIV prevention interventions has increased over time with much significant increase in the intensive exposure across all the four routes (NE: from 14.9% to 28%, P study results highlight the ability of intensive program to reach truckers who have sex outside marriage with HIV prevention interventions and promote safe sex behaviors among them. Truckers who practice safe sex behaviors with an exposure to intensive program are less likely to suffer from STIs and HIV, which has implications for HIV prevention program with truckers' population in India and elsewhere. The simultaneous targeted interventions among female sex workers appeared to have contributed to safe sexual practices among

  5. Effects of carbohydrate ingestion on acute leukocyte, cortisol, and interleukin-6 response in high-intensity long-distance running.

    Science.gov (United States)

    Ihalainen, Johanna K; Vuorimaa, Timo; Puurtinen, Risto; Hämäläinen, Ismo; Mero, Antti A

    2014-10-01

    The purpose of this study was to investigate the effect of ingestion of fluids with different carbohydrate concentrations (0, 1.5, and 7%) on the acute immune stress responses after high-intensity long-distance running. Continuous 18- to 20-km run was performed at 75% of maximal oxygen uptake with carbohydrate supplementation (CHO7%, 7% carbohydrate solution) and low-carbohydrate supplementation (lowCHO1.5%, 1.5% carbohydrate solution) in a randomized, double-blind, placebo (PLA) controlled design. Seven recreational runners (4 men and 3 women) completed all 3 trials. Blood was collected at baseline (PRE) and immediately after the run (POST). The running task induced significant (p ≤ 0.05) increases in leukocyte (white blood cells), neutrophil, and interleukin-6 (IL-6) counts in every trial. There was a significant (p ≤ 0.05) increase in cortisol with PLA and lowCHO1.5% but not with CHO7%. Increase in total leukocyte and neutrophil concentration was significantly lower with CHO7% compared with PLA (p ≤ 0.05). Postexercise IL-6 levels were significantly elevated when compared with baseline in all conditions (p ≤ 0.05). Interleukin-6 (IL-6) concentrations did not differ significantly between trials. LowCHO1.5% sport drink did not significantly differ from PLA in measured variables, which indicated that the amount and rate of carbohydrate ingestion (15 g, 10 g·h) in low-carbohydrate sport drink was not enough to significantly protect from the stress induced by high-intensity long-distance running, whereas the ingestion of CHO7% (45 g·h) blunted the significant cortisol response and significantly decreased the leukocyte response.

  6. Cancer incidence in participants in a long-distance ski race (Vasaloppet, Sweden) compared to the background population.

    Science.gov (United States)

    Hållmarker, Ulf; James, Stefan; Michaëlsson, Karl; Ärnlöv, Johan; Sandin, Fredrik; Holmberg, Lars

    2015-03-01

    We studied the association between taking part in a long distance ski race and cancer incidence to address the hypothesis that a lifestyle involving a high degree of physical activity (PA) lowers cancer incidence with a pattern that is different by cancer site. Cancer incidence was estimated in a large cohort of skiers (n=185,412) participating in the Vasaloppet long distance ski race in Sweden 1989-2010 and non-participants in the ski race, randomly selected from the Swedish general population (n=184,617). Data include race finishing times as a measurement of physical fitness. Hazard ratios (HRs) and net probability of cancer over twenty years of follow-up were estimated for all invasive cancer, and separately for prostate, breast, colo-rectal and lung cancer, and groups of cancers with presumed relation to lifestyle. Participating in Vasaloppet was associated with a relative risk reduction for all invasive cancer of 6% (95% confidence interval 2-9%) and a relative risk reduction of 32% (95% confidence interval 28-37%) of cancer sites where there is epidemiological evidence that smoking, bodyweight, regular PA and consumption of fruit and vegetables are aetiological factors. For skin cancer the risk was increased, as for prostate cancer. Skiers with shorter finishing times had lower incidence of cancer. This study indicates that it is unrealistic to reduce overall population cancer incidence drastically with life style. However, cancers that are epidemiologically associated with life style factors were significantly reduced by what presumably is a blend of non-smoking, normal body weight, sound dietary habits and PA. Our data thus provide additional support for present days' recommendations about life style prevention. Higher health awareness is associated with attendance to screening, which may explain our results for prostate cancer. University fund, independent funds from an insurance company and a private foundation. Copyright © 2014 Elsevier Ltd. All rights

  7. Application of fiber Bragg grating sensing technology in long-distance detection of temperature in weapon depots

    Science.gov (United States)

    Xu, Jianguo; Zhang, ZhiLi; Zhao, Bing; Fu, Zhulin

    2010-10-01

    Incessantly long-term real-time detection of temperature is demanded in weapon depots, where the weapon equipment is stored in, to realize the self-regulation of temperature. Long-Distance intellectualized control can be actualized by setting sensor-net which is composed by several temperature sensors to simultaneously detect multi-point and multi- parameter. The temperature sensors based on Fiber Bragg Grating Technology are more suitable for long-term detection for their preponderance in high sensitivity, small volume, anti-jamming and so on. The temperature sensing system, which is composed by several Fiber Bragg Grating sensors in one light-cable, can accomplish Quasi-Distributed measurement and is suitable for multi-point and multi- parameter detection. Basal principle of Fiber Bragg Grating sensing technology is expounded in the article, with a sensing system applied to the long-distance detection of temperature in the depots is designed based on F-P Scanning Method. Besides, DSP and FPGA are adopted pre-treat the transformed data from AD such as filter and determine threshold. The main modules of this demodulation system such as 1550nm exact photoelectric detection module and trigonal wave voltage scan module are designed in this paper to realize demodulation. Proved by the analysis of the testing data, the Fiber Bragg Grating temperature sensing system, whose testing precision achieved the design purpose, has advantages of real-time measure and long-term stability. The system, which provides guarantee to realize the auto-control of temperature, can be generalized and will provide favorable foundation for the broad using of Fiber Bragg Grating sensing technology in the army.

  8. Germination and storage of pollen

    NARCIS (Netherlands)

    Visser, T.

    1955-01-01

    Germination of pear pollen markedly improved when boric acid was added to the medium. The pollen was more sensitive to boron in water than in 10 % sugar solution. Supplying weak solutions of boron to pear branches before flowering resulted in a good germination of the pollen in sugar solution withou

  9. Hybridizing pines with diluted pollen

    Science.gov (United States)

    Robert Z. Callaham

    1967-01-01

    Diluted pollens would have many uses by the tree breeder. Dilutions would be particularly advantageous in making many controlled pollinations with a limited amount of pollen. They also would be useful in artificial mass pollinations of orchards or single trees. Diluted pollens might help overcome troublesome genetic barriers to crossing. Feasibility o,f using diluted...

  10. Pollen morphology of the Stemonaceae

    NARCIS (Netherlands)

    Ham, van der R.W.J.M.

    1991-01-01

    A pollen-morphological survey of all four genera of the Stemonaceae at the light and electron microscope level is presented. Stemonaceae is a eurypalynous family. Stichoneuron pollen, up to now described as monosulcate, appears to be inaperturate. Pentastemona pollen is most deviating in Stemonaceae

  11. An Electrostatic-Barrier-Forming Window that Captures Airborne Pollen Grains to Prevent Pollinosis

    Science.gov (United States)

    Takikawa, Yoshihiro; Matsuda, Yoshinori; Nonomura, Teruo; Kakutani, Koji; Kusakari, Shin-Ichi; Toyoda, Hideyoshi

    2017-01-01

    An electrostatic-barrier-forming window (EBW) was devised to capture airborne pollen, which can cause allergic pollinosis. The EBW consisted of three layers of insulated conductor wires (ICWs) and two voltage generators that supplied negative charges to the two outer ICW layers and a positive charge to the middle ICW layer. The ICWs generated an attractive force that captured pollen of the Japanese cedar, Cryptomeria japonica, from air blown through the EBW. The attractive force was directly proportional to the applied voltage. At ≥3.5 kV, the EBW exerted sufficient force to capture all pollen carried at an air flow of 3 m/s, and pollen-free air passed through the EBW. The findings demonstrated that the electrostatic barrier that formed inside the EBW was very effective at capturing airborne pollen; thus, it could allow a home to remain pollen-free and healthy despite continuous pollen exposure.

  12. Examination of climatological wind patterns and simulated pollen dispersion in a complex island environment.

    Science.gov (United States)

    Viner, Brian J; Arritt, Raymond W; Westgate, Mark E

    2017-03-29

    Complex terrain creates small-scale circulations which affect pollen dispersion but may be missed by meteorological observing networks and coarse-grid meteorological models. On volcanic islands, these circulations result from differing rates of surface heating between land and sea as well as rugged terrain. We simulated the transport of bentgrass, ryegrass, and maize pollen from 30 sources within the agricultural regions of the Hawaiian island Kaua'i during climatological conditions spanning season conditions and the La Niña, El Niño, and neutral phases of the El Niño-Southern Oscillation. Both pollen size and source location had major effects on predicted dispersion over and near the island. Three patterns of pollen dispersion were identified in response to prevailing wind conditions: southwest winds transported pollen inland, funneling pollen grains through valleys; east winds transported pollen over the ocean, with dispersive tails for the smallest pollen grains following the mean wind and extending as far as the island of Ni'ihau 35 km away; and northeast winds moved pollen inland counter to the prevailing flow due to a sea breeze circulation that formed over the source region. These results are the first to predict the interactions between complex island terrain and local climatology on grass pollen dispersion. They demonstrate how numerical modeling can provide guidance for field trials by illustrating the common flow regimes present in complex terrain, allowing field trials to focus on areas where successful sampling is more likely to occur.

  13. Comparative Proteomic Analysis of Arabidopsis Mature Pollen and Germinated Pollen

    Institute of Scientific and Technical Information of China (English)

    Junjie Zou; Lianfen Song; Wenzheng Zhang; Yi Wang; Songlin Ruan; Wei-Hua Wu

    2009-01-01

    Proteomic analysis was applied to generating the map of Arabidopsis mature pollen proteins and analyzing the differentially expressed proteins that are potentially involved in the regulation of Arabidopsis pollen germination. By applying 2-D electrophoresis and silver staining, we resolved 499 and 494 protein spots from protein samples extracted from pollen grains and pollen tubes, respectively. Using the matrix-assisted laser desorption ionization time-of-flight mass spectrometry method, we identified 189 distinct proteins from 213 protein spots expressed in mature pollen or pollen tubes, and 75 new identified proteins that had not been reported before in research into the Arabidopsis pollen proteome. Comparative analysis revealed that 40 protein spots exhibit reproducible significant changes between mature pollen and pollen tubes. And 21 proteins from 17 downregulated and six upregulated protein spots were identified. Functional category analysis indicated that these differentially expressed proteins mainly involved in signaling, cellular structure, transport, defense/stress responses, transcription, metabolism, and energy production. The patterns of changes at protein level suggested the important roles for energy metabolism-related proteins in pollen tube growth, accompanied by the activation of the stress response pathway and modifications to the cell wall.

  14. Testing an attachment method for solar-powered tracking devices on a long-distance migrating shorebird

    Science.gov (United States)

    Chan, Ying-Chi; Brugge, Martin; Tibbitts, T. Lee; Dekinga, Anne; Porter, Ron; Klaassen, Raymond H. G.; Piersma, Theunis

    2016-01-01

    Small solar-powered satellite transmitters and GPS data loggers enable continuous, multi-year, and global tracking of birds. What is lacking, however, are reliable methods to attach these tracking devices to small migratory birds so that (1) flight performance is not impacted and (2) tags are retained during periods of substantial mass change associated with long-distance migration. We developed a full-body harness to attach tags to Red Knots (Calidris canutus), a medium-sized shorebird (average mass 124 g) that undertakes long-distance migrations. First, we deployed dummy tags on captive birds and monitored them over a complete migratory fattening cycle (February–July 2013) during which time they gained and lost 31–110 g and underwent a pre-alternate moult of body feathers. Using each individual’s previous year fattening and moult data in captivity as controls, we compared individual mass and moult differences between years between the tagged and reference groups, and concluded that the attachment did not impact mass and moult cycles. However, some birds shed feathers under the tags and under the polyester harness line commonly used in avian harnesses. Feather shedding was alleviated by switching to smoothed-bottom tags and monofilament harness lines. To field-trial this design, we deployed 5-g satellite transmitters on ten Red Knots released on 3 October 2013 in the Dutch Wadden Sea. Bird movements and tag performance appeared normal. However, nine tags stopped transmitting 11–170 days post-release which was earlier than expected. We attribute this to bird mortality rather than failure of the attachments or transmitters and suggest that the extra weight and drag caused by the tag and its feather-blocking shield increased the chance of depredation by the locally common Peregrine Falcons (Falco peregrinus). Our results demonstrate that species- and place-specific contexts can strongly determine tagging success. While captive trials are an important first

  15. HIV infection in long-distance truck drivers in a low income setting in the Niger Delta of Nigeria.

    Science.gov (United States)

    Azuonwu, Obioma; Erhabor, Osaro; Frank-Peterside, Nnenna

    2011-08-01

    The aim of this study was to determine the seroprevalence, and correlates of HIV infection among long-distance truck drivers in Port Harcourt, Nigeria. A total of one hundred (100) long-distance truck drivers aged between 21 and 60 years and mean age of 42.36 ± 5.23 years were screened for the presence of HIV antibodies. The results showed that, out of the total number screened 10 (10%) were positive for HIV while 90 (90%) were negative. The prevalence of HIV was significantly higher in the 31-40 years age group 6/26 (23%) compared to 1/13 (7.6%) in the 21-30 years age group and 2/37 (7.4%) in the 51-60 years age group (P = 0.04).The lowest prevalence of HIV occurred in the 41-50 years age group 1/24 (4.2%). HIV 1 was the predominant viral subtype among the subjects 9 (90%) while 1 (10%) had HIV-2. None of the HIV-positive subjects had dual HIV 1 and 2 infections. The mean CD4 lymphocyte count for subjects positive for HIV was 380 ± 68.0 (range 312-448 cells/μl) while CD4 count for HIV negative subjects was 780 ± 76 cells/μl (range 704-856 cells/μl. A significant negative correlation was observed between HIV positivity and CD4 count r = -0.010 (P = 0.01). It is recommended that intensive preventive measures be instituted coupled with the implementation of a vigorous enlightenment campaign targeting behavioral change from high risk culture among truckers. Efforts are urgently needed to provide access to sexual health education, treatment services and HIV testing facilities to reduce their vulnerability to HIV infection.

  16. The use anesthetic agents to promote welfare in anemonefish aquaculture: Case study to handling and long-distance transport

    Directory of Open Access Journals (Sweden)

    João Chambel

    2014-06-01

    The aim of this study was to evaluate the efficacy of three anaesthetic agents (80 to 110 mg/L of MS-222, 10 to 30 mg/L of clove oil and 100 to 350 mg/L of 2-phenoxyethanol in anaesthesia and the success of use different clove oil concentrations (1, 3 and 10 mg/L on water quality and survival of an ornamental anemonefish, Amphiprion percula, during long-distance transport in closed system for 48 hours. The lowest effective concentrations based on the efficacy criteria of complete anaesthetic induction within 180s, recovery within 300s and survival when exposed 30 min to anaesthetic was 15 mg/l for clove oil, 200 µl/L for 2-phenoxyethanol and 85 mg/L for MS-222. Above the concentrations of 30 mg/L, 300 µl/L and 100 mg/L of clove oil, 2-phenoxyethanol and MS-222 respectively, fish did not recovery when exposed to anaesthetic during 30min. During long-distance transport, clove oil slowed the increase on the ammonia concentration and the decrease on oxygen level, but did not affect the pH and only at concentration of 10 mg/L increase de mortality at 36 and 48 hours after packed. All concentrations showed a significance increase on water quality, reducing total ammonia from 9.31 ± 0.58 mg/L (control group to 5.43 ± 0.56 mg/L (1mg/L, 4.97 ± 0.59 mg/L (3mg/L and 3.88 ± 0.14 mg/L (10mg/L. This study showed that all anaesthetic agents under study can be used in anaesthesia of percula clownfish with optimal doses varied according to the anaesthetic, 15 to 25 mg/L of clove oil, 200 to 250 of 2-phenoxyethanol and 85 to 90 mg/L of MS-222, but clove oil was the anaesthetic agent more effectiveness and with major margin of safety for percula clownfish, and this anaesthesic (clove oil can be used in ornamental fish transportation, reducing the deterioration in water quality and ensuring a better transport environment and reduced stress for the fish. However must be careful related the dose in use, because an excess anesthesic may reduce dissolved oxygen and cause high

  17. Noncontact ultrasonic transportation of small objects over long distances in air using a bending vibrator and a reflector.

    Science.gov (United States)

    Koyama, Daisuke; Nakamura, Kentaro

    2010-05-01

    Ultrasonic manipulation of small particles, including liquid droplets, over long distances is discussed. It is well known that particles can be trapped at the nodal points of an acoustic standing wave if the particles are much smaller than the wavelength of the standing wave. We used an experimental setup consisting of a 3-mm-thick, 605-mm-long duralumin bending vibrating plate and a reflector. A bolt-clamped Langevin transducer with horn was attached to each end of the vibrating plate to generate flexural vibrations along the plate. A plane reflector with the same dimensions as the vibrating plate was installed parallel to the plate at a distance of approximately 17 mm to generate an ultrasonic standing wave between them and to trap the small particles at the nodal lines. The acoustic field and acoustic radiation force between the vibrator and reflector were calculated by finite element analysis to predict the positions of the trapped particles. The sound pressure distribution was measured experimentally using a scanning laser Doppler vibrometer. By controlling the driving phase difference between the two transducers, a flexural traveling wave can be generated along the vibrating plate, and the vertical nodal lines of the standing wave and the trapped particles can be moved. The flexural wave was excited along the vibrator at 22.5 kHz. A lattice standing wave with a wavelength of 35 mm in the length direction could be excited between the vibrator and the reflector, and polystyrene spheres with diameters of several millimeters could be trapped at the nodal lines of the standing wave. The experimental and calculated results showed good agreement for the relationship between the driving phase difference and the positions of the trapped particles. Noncontact transportation of the trapped particles over long distances could be achieved by changing the driving phase difference. The position of the trapped particles could be controlled to an accuracy of 0.046 mm/deg. An

  18. Stomatal movement in response to long distance- communicated signals initiated by heat shock in partial roots of Commelina communis L.

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The systematic or long-distance signal transmission plays crucial roles in animal lives. Compared with animals, however, much less is known about the roles of long-distance signal communication in plant lives. Using the model plant Commelina communis L., we have probed the root to shoot communication mediated by heat-shock signals. The results showed that a heat shock of 5 min at 40℃ in partial roots, i.e. half or even 1/4 root system, could lead to a significant decrease in stomatal conductance. The regulation capability depends on both heat shock temperature and the amount of root system, i.e. with higher temperature and more roots stressed, the leaf conductance would decrease more significantly. Interestingly, the stomatal regulation by heat shock signal is in a manner of oscillation: when stomata conductance decreased to the lowest level within about 30 min, it would increase rapidly and sometimes even exceed the initial level, and after several cycles the stomata conductance would be finally stabilized at a lower level. Feeding xylem sap collected from heat-shocked plants could lead to a decrease in stomata conductance, suggesting that the heat shock-initiated signal is basically a positive signal. Further studies showed that heat shock was not able to affect ABA content in xylem sap, and also, not able to lead to a decrease in leaf water status, which suggested that the stomatal regulation was neither mediated by ABA nor by a hydraulic signal. Heat shock could lead to an increase in xylem sap H2O2 content, and moreover, the removal of H2O2 by catalase could partially recover the stomatal inhibition by xylem sap collected from heat-shocked plants, suggesting that H2O2 might be able to act as one of the root signals to control the stomatal movement. Due to the fact that heat-shock and drought are usually two concomitant stresses, the stomatal regulation by heat-shock signal should be of significance for plant response to stresses. The observation for the

  19. An approach for estimating the radiological significance of a hypothetical major nuclear accident over long distance transboundary scales

    Energy Technology Data Exchange (ETDEWEB)

    Mitrakos, D., E-mail: dimitris.mitrakos@eeae.gr; Potiriadis, C.; Housiadas, C.

    2016-04-15

    Highlights: • Actions may be warranted after a major nuclear accident even at long distances. • Distance may not be the decisive parameter for longer term radiological impact. • Remote impact may vary orders of magnitude depending on the meteorological conditions. • The potential impact can be assessed using computationally inexpensive calculations. - Abstract: After the Fukushima accident important initiatives were taken in European level to enhance the nuclear safety level of the existing and planned nuclear reactors, such as the so-called nuclear “stress-tests” and the amendment of the Nuclear Safety Directive. A recent work of HERCA and WENRA focused on the need for a more consistent and harmonized response in a transboundary context in case of a hypothetical major nuclear accident in Europe. Such an accident, although very improbable, cannot be totally excluded and so, should be considered in emergency preparedness arrangements among the various European countries. In case of a hypothetical severe Fukushima-like accident in Europe, the role of the neighboring countries may be important, since the authorities should be able to provide information and advice to the government and the public, but also can contribute to the overall assessment of the situation be their own means. In this work we assess the radiological significance of a hypothetical major nuclear accident for distances longer than 300 km that are not typically covered by the internationally accepted emergency planning zones. The approach is simple and computationally inexpensive, since it is based on the calculation of only a few release scenarios at dates selected within a whole year on the basis of bounding the deposition levels at long distances in relation to the occurrence of precipitation. From the calculated results it is evident that distance is not the only decisive parameter in estimating the potential radiological significance of a severe nuclear accident. The hypothetical

  20. Battlefield Tourism at Gallipoli: The Revival of Collective Memory, the Construction of National Identity and the Making of a Long-distance Tourism Network

    Directory of Open Access Journals (Sweden)

    Elif Yeneroglu Kutbay

    2016-11-01

    Full Text Available The Battle of the Dardanelles (Çanakkale, also known as the Gallipoli Campaign, played a crucial role in the construction and endorsement of national identity, irrespective of the immediate consequences such as the prolongation of the war or the resignation of Winston Churchill upon failure. The Battle of the Dardanelles is commemorated every year in Turkey, Australia and New Zealand, as a day of remembrance. The battlefields at Dardanelles were reinstated as the Gallipoli Peninsula Historical National Park in 1973. The park covers numerous cemeteries of soldiers from both sides, memorials, museums and the battlefields in an area of 33,000 hectares. The park provides a vivid setting and depiction of the war experience, and stands out as the most important battlefield site in Turkey.The aim of this paper is to analyze battlefield tourism in Çanakkale in terms of its components and its impact on domestic and international tourism in Turkey. Battlefield tourism in Çanakkale encompasses not only the battlefield itself, but also the Çanakkale Victory Day in Turkey, March 18th, and the Anzac Day in Australia, April 25th. While domestic tourism contributes to the revival of collective memory and to the building of national identity, international tourism provides representations of national heritage as a source of political legitimacy. Unique to this case, battlefield tourism plays a significant role in the construction of a long-distance tourism network between Australia, and Turkey. The annual flow of descendants of ANZAC (Australian and New Zealand Army Corps soldiers is an important source of tourism activity in the area.

  1. The Heavy Vehicle Study: a case-control study investigating risk factors for crash in long distance heavy vehicle drivers in Australia

    Directory of Open Access Journals (Sweden)

    Grunstein Ron R

    2010-03-01

    Full Text Available Abstract Background Heavy vehicle transportation continues to grow internationally; yet crash rates are high, and the risk of injury and death extends to all road users. The work environment for the heavy vehicle driver poses many challenges; conditions such as scheduling and payment are proposed risk factors for crash, yet the precise measure of these needs quantifying. Other risk factors such as sleep disorders including obstructive sleep apnoea have been shown to increase crash risk in motor vehicle drivers however the risk of heavy vehicle crash from this and related health conditions needs detailed investigation. Methods and Design The proposed case control study will recruit 1034 long distance heavy vehicle drivers: 517 who have crashed and 517 who have not. All participants will be interviewed at length, regarding their driving and crash history, typical workloads, scheduling and payment, trip history over several days, sleep patterns, health, and substance use. All participants will have administered a nasal flow monitor for the detection of obstructive sleep apnoea. Discussion Significant attention has been paid to the enforcement of legislation aiming to deter problems such as excess loading, speeding and substance use; however, there is inconclusive evidence as to the direction and strength of associations of many other postulated risk factors for heavy vehicle crashes. The influence of factors such as remuneration and scheduling on crash risk is unclear; so too the association between sleep apnoea and the risk of heavy vehicle driver crash. Contributory factors such as sleep quality and quantity, body mass and health status will be investigated. Quantifying the measure of effect of these factors on the heavy vehicle driver will inform policy development that aims toward safer driving practices and reduction in heavy vehicle crash; protecting the lives of many on the road network.

  2. Characteristics of Loads of Cattle Stopping for Feed, Water and Rest during Long-Distance Transport in Canada

    Directory of Open Access Journals (Sweden)

    Hannah E. Flint

    2014-03-01

    Full Text Available This study is the first comprehensive examination of long-haul cattle being transported across Canada and off-loaded for feed, water and rest. A total of 129 truckloads were observed at one of two commercial rest stations near Thunder Bay, Ontario. Data collected included information regarding the truck driver, the trailer, the trip, the animals and animal handling. The majority of the loads stopping were feeder calves (60.94% while 21.09% were weaned calves, and the remaining 14.84% were market weight cattle. The truck loads surveyed were in transit for, on average, 28.2 ± 5.0 hours before stopping and cattle were rested for an average of 11.2 ± 2.8 hours. These data suggest that loads stopping at the rest station were adhering to the regulations stated in the Health of Animals Act, which outline a maximum of 48 hours in transit before a mandatory stop of at least 5 hours for feed, water and rest. There was a large amount of variability around how well recommendations, such as stocking density were followed. Further research is required to assess how well cattle are coping with long-distance transport under current regulations and industry practices.

  3. Advanced autumn migration of sparrowhawk has increased the predation risk of long-distance migrants in Finland.

    Directory of Open Access Journals (Sweden)

    Aleksi Lehikoinen

    Full Text Available Predation affects life history traits of nearly all organisms and the population consequences of predator avoidance are often larger than predation itself. Climate change has been shown to cause phenological changes. These changes are not necessarily similar between species and may cause mismatches between prey and predator. Eurasian sparrowhawk Accipiter nisus, the main predator of passerines, has advanced its autumn phenology by about ten days in 30 years due to climate change. However, we do not know if sparrowhawk migrate earlier in response to earlier migration by its prey or if earlier sparrowhawk migration results in changes to predation risk on its prey. By using the median departure date of 41 passerine species I was able to show that early migrating passerines tend to advance, and late migrating species delay their departure, but none of the species have advanced their departure times as much as the sparrowhawk. This has lead to a situation of increased predation risk on early migrating long-distance migrants (LDM and decreased the overlap of migration season with later departing short-distance migrants (SDM. Findings highlight the growing list of problems of declining LDM populations caused by climate change. On the other hand it seems that the autumn migration may become safer for SDM whose populations are growing. Results demonstrate that passerines show very conservative response in autumn phenology to climate change, and thus phenological mismatches caused by global warming are not necessarily increasing towards the higher trophic levels.

  4. Long-distance autumn migration across the Sahara by painted lady butterflies: exploiting resource pulses in the tropical savannah.

    Science.gov (United States)

    Stefanescu, Constantí; Soto, David X; Talavera, Gerard; Vila, Roger; Hobson, Keith A

    2016-10-01

    The painted lady, Vanessa cardui, is a migratory butterfly that performs an annual multi-generational migration between Europe and North Africa. Its seasonal appearance south of the Sahara in autumn is well known and has led to the suggestion that it results from extremely long migratory flights by European butterflies to seasonally exploit the Sahel and the tropical savannah. However, this possibility has remained unproven. Here, we analyse the isotopic composition of butterflies from seven European and seven African countries to provide new support for this hypothesis. Each individual was assigned a geographical natal origin, based on its wing stable hydrogen isotope (δ(2)Hw) value and a predicted δ(2)Hw basemap for Europe and northern Africa. Natal assignments of autumn migrants collected south of the Sahara confirmed long-distance movements (of 4000 km or more) starting in Europe. Samples from Maghreb revealed a mixed origin of migrants, with most individuals with a European origin, but others having originated in the Sahel. Therefore, autumn movements are not only directed to northwestern Africa, but also include southward and northward flights across the Sahara. Through this remarkable behaviour, the productive but highly seasonal region south of the Sahara is incorporated into the migratory circuit of V. cardui.

  5. Local melatonin application induces cold tolerance in distant organs of Citrullus lanatus L. via long distance transport.

    Science.gov (United States)

    Li, Hao; Chang, Jingjing; Zheng, Junxian; Dong, Yuchuan; Liu, Qiyan; Yang, Xiaozhen; Wei, Chunhua; Zhang, Yong; Ma, Jianxiang; Zhang, Xian

    2017-01-19

    Melatonin is a ubiquitous chemical substance that regulates plant growth and responses to stress. Several recent studies show that exogenous melatonin confers cold tolerance to plants; however, the underlying mechanisms remain largely unknown. Here, we report that melatonin application at optimal dose, either on the leaves or the roots, not only induced cold stress tolerance in the site of application, but also systemically induced cold tolerance in untreated distant parts. Foliar or rhizospheric treatment with melatonin increased the melatonin levels in untreated roots or leaves, respectively, under both normal and cold stress conditions, whereas rhizospheric melatonin treatment increased the melatonin exudation rates from the xylem. An increased accumulation of melatonin accompanied with an induction in antioxidant enzyme activity in distant untreated tissues alleviated cold-induced oxidative stress. In addition, RNA-seq analysis revealed that an abundance of cold defense-related genes involved in signal sensing and transduction, transcriptional regulation, protection and detoxification, and hormone signaling might mediate melatonin-induced cold tolerance. Taken together, our results suggest that melatonin can induce cold tolerance via long distance signaling, and such induction is associated with an enhanced antioxidant capacity and optimized defense gene expression. Such a mechanism can be greatly exploited to benefit the agricultural production.

  6. Long-distance transport of ventilated patients: advantages and limitations of air medical repatriation on commercial airlines.

    Science.gov (United States)

    Veldman, Alex; Diefenbach, Michael; Fischer, Doris; Benton, Alida; Bloch, Richard

    2004-01-01

    To illustrate the advantages and limitations of transporting ventilated intensive care unit patients over intercontinental distances on commercial airlines, this case series reports 8 ventilated patients repatriated by an air medical transport company. Eight ventilated patients, 3 suffering from internal and 5 from neurologic diseases. Distances ranged from 1700 to 10280 nautical miles with transport times from 04:10 hours to 21:55 hours. For 3 patients, a dedicated patient transport compartment (PTC) in the aircraft cabin was used. All patients were ventilator-dependent for a minimum of 11 days before transport (48 days median, 113 days maximum). One patient went into cardiac arrest during the flight and died. None of the other patients experienced any emergency or invasive procedures, other than peripheral venous access necessary during the flight. In all patients, ventilation was adjusted with respect to the blood gas analysis at least once during the transport. No technical failures or drop-outs occurred during the flights. None of the flights had to be diverted for technical or medical reasons. Long distance international transport of ventilated intensive care unit patients is an extremely cost intensive and logistically challenging task. In a certain subgroup of relatively stable ventilated patients, transport on commercial airlines offers advantages in terms of cost effectiveness and reduced transport time and acceleration/deceleration trauma as a result of multiple fuel stops.

  7. Long-distance propagation of pseudo-partially coherent Gaussian Schell-model beams in atmospheric turbulence

    Institute of Scientific and Technical Information of China (English)

    Qian Xian-Mei; Zhu Wen-Yue; Rao Rui-Zhong

    2012-01-01

    Propagation properties of spatially pseudo-partially coherent Gaussian Schell-model beams through the atmospheric turbulence over a long-distance uplink path are studied by numerical simulation.A linear coordination transformation is introduced to overcome the window effect and the loss-of-resolution problem.The beam spreading,beam wandering,and intensity scintillation as functions of turbulence strength,source correlation length,and change frequency of random phase that models the partial coherence of the source are analyzed. It is found that the beam spreading and the intensity scintillation of the partially coherent beam are less affected by the turbulence than those of the coherent one,but it suffers from a more severe diffractive effect,and the change frequency of random phase has no evident influence on it.The beam wandering is insensitive to the variation of source correlation length,and decreases firstly then goes to a fixed value as the change frequency increases.

  8. Confinement understanding the relation between the Wilson loop and dual theories of long distance Yang Mills theory

    CERN Document Server

    Baker, M; Brambilla, Nora; Prosperi, G M; Zachariasen, F

    1995-01-01

    In this paper we express the velocity dependent, spin dependent heavy quark potential V_{q\\bar q} in QCD in terms of a Wilson Loop W(\\Gamma) determined by pure Yang Mills theory. We use an effective dual theory of long-distance Yang Mills theory to calculate W(\\Gamma) for large loops; i.e. for loops of size R > R_{FT}. (R_{FT} is the flux tube radius, fixed by the value of the Higgs (monopole) mass of the dual theory, which is a concrete realization of the Mandelstam 't Hooft dual superconductor mechanism of confinement). We replace W(\\Gamma) by W_{eff}(\\Gamma), given by a functional integral over the dual variables, which for R > R_{FT} can be evaluated by a semiclassical expansion, since the dual theory is weakly coupled at these distances. The classical approximation gives the leading contribution to W_{eff}(\\Gamma) and yields a velocity dependent heavy quark potential which for large R becomes linear in R, and which for small R approaches lowest order perturbative QCD. This latter fact means that these re...

  9. Material Independent Long Distance Pulling, Trapping, and Rotation of Fully Immersed Multiple Objects with a Single Optical Set-up

    CERN Document Server

    Rahman, Md Masudur; Mahdy, Mahdy Rahman Chowdhury; Haque, Md Ehsanul; Islam, Rakibul; Chowdhury, S Tanvir-ur-Rahman; Nieto-Vesperinas, Manuel; Matin, Md Abdul

    2015-01-01

    Optical pulling with tractor beams is so far highly dependent on (i) the property of embedding background or the particle itself , (ii) the number of the particles and/or (iii) the manual ramping of beam phase. A necessary theoretical solution of these problems is proposed here. This article demonstrates a novel active tractor beam for multiple fully immersed objects with its additional abilities of yielding a controlled rotation and a desired 3D trapping. Continuous and stable long distance levitation, controlled rotation and 3D trapping are demonstrated with a single optical set-up by using two coaxial, or even non-coaxial, superimposed non-diffracting higher order Bessel beams of reverse helical nature and different frequencies. The superimposed beam has periodic intensity variations both along and around the beam-axis because of the difference in longitudinal wave-vectors and beam orders, respectively. The difference in frequencies of two laser beams makes the intensity pattern move along and around the b...

  10. Long Distance Truck Drivers and the Structural Context of Health: A Culture-Centered Investigation of Indian Truckers' Health Narratives.

    Science.gov (United States)

    Sastry, Shaunak

    2016-01-01

    Long-distance truck drivers (truckers) in India have been identified as a "high-risk" group for the HIV/AIDS epidemic, and are consequently the targets of prevention and education-based interventions. While such interventions have addressed risk at the level of individual behavior, little attention has been paid to the structural barriers to health for truckers. Research among truckers in India has ignored the economic, social, and cultural context of health. In this article, I employ the culture-centered approach (CCA) to health communication in documenting truckers' narratives of health, which are innately connected to social and institutional structures around their lives. The data included 36 narrative interviews that I conducted as part of my fieldwork with Indian truckers, in addition to field notes and a reflexive journal. Through a reflexive analysis of these narratives, I present three themes: (a) the everyday violence of trucking, (b) health as sacrifice, and (c) migration and HIV/AIDS. I discuss how communication interventions can attend to the relationship between trucker health and the structural barriers they encounter.

  11. Regulation of TCR delta and alpha repertoires by local and long-distance control of variable gene segment chromatin structure.

    Science.gov (United States)

    Hawwari, Abbas; Krangel, Michael S

    2005-08-15

    Murine Tcrd and Tcra gene segments reside in a single genetic locus and undergo recombination in CD4- CD8- (double negative [DN]) and CD4+ CD8+ (double positive [DP]) thymocytes, respectively. TcraTcrd locus variable gene segments are subject to complex regulation. Only a small subset of approximately 100 variable gene segments contributes substantially to the adult TCRdelta repertoire. Moreover, although most contribute to the TCRalpha repertoire, variable gene segments that are Jalpha proximal are preferentially used during primary Tcra recombination. We investigate the role of local chromatin accessibility in determining the developmental pattern of TcraTcrd locus variable gene segment recombination. We find variable gene segments to be heterogeneous with respect to acetylation of histones H3 and H4. Those that dominate the adult TCRdelta repertoire are hyperacetylated in DN thymocytes, independent of their position in the locus. Moreover, proximal variable gene segments show dramatic increases in histone acetylation and germline transcription in DP thymocytes, a result of super long-distance regulation by the Tcra enhancer. Our results imply that differences in chromatin accessibility contribute to biases in TcraTcrd locus variable gene segment recombination in DN and DP thymocytes and extend the distance over which the Tcra enhancer can regulate chromatin structure to a remarkable 525 kb.

  12. Long-distance axonal regeneration in the filum terminale of adult rats is regulated by ependymal cells.

    Science.gov (United States)

    Kwiecien, Jacek M; Avram, Ronen

    2008-03-01

    Studies of regeneration of transected adult central nervous system (CNS) axons are difficult due to lack of appropriate in vivo models. In adult rats, we described filum terminale (FT), a caudal slender extension of the sacral spinal cord and an integral part of the central nervous system (CNS), to use it as a model of spinal cord injury. FT is more than 3 cm long, encompasses a central canal lined with ependymal cells surrounded by a narrow band of axons interspersed with oligodendrocytes and astrocytes but not neurons. Two weeks after the crush of FT, histological, ultrastructural, and axonal tracing studies revealed long distance descending axonal regeneration uniquely in close proximity of the ependymal cells of the central canal. Ependymal cells extended basal processes to form channels encompassing axons apparently regenerating at a rate of more than 2 mm a day. Remarkable increase of axonal sprouting was observed in the sacral spinal cord of Long Evans Shaker (LES) rats with crushed FT. FT offers an excellent model to study mechanisms of axonal regeneration regulated by ependymal cells in the adult CNS.

  13. Simultaneous Vehicle and Crew Routing and Scheduling for Partial- and Full-Load Long-Distance Road Transport

    Directory of Open Access Journals (Sweden)

    Michael Drexl

    2013-11-01

    Full Text Available This paper studies a simultaneous vehicle and crew routing and scheduling problem arising in long-distance road transport in Europe: Pickup-and-delivery requests have to be fulfilled over a multi-period planning horizon by a heterogeneous fleet of trucks and drivers. Typically, in the vehicle routing literature, a fixed assignment of a driver to a truck is assumed. In our approach, we abandon this assumption and allow truck/driver changes at geographically dispersed relay stations. This offers greater planning flexibility and allows a better utilization of trucks, but also creates intricate interdependencies between trucks and drivers and requires the synchronization of their routes. A solution heuristic based on a two-stage decomposition of the problem is developed, taking into account European Union social legislation for drivers, and computational experiments using real-world data provided by a major German forwarder are presented and analyzed. The obtained results suggest that for the vehicle and driver cost structure prevalent in Western Europe and for transport requests that are not systematically acquired to complement one another, no cost savings are possible through simultaneous vehicle and crew routing and scheduling, although no formal proof of this fact is possible.

  14. A Proposed Scalable Design and Simulation of Wireless Sensor Network-Based Long-Distance Water Pipeline Leakage Monitoring System

    Directory of Open Access Journals (Sweden)

    Abdulaziz S. Almazyad

    2014-02-01

    Full Text Available Anomalies such as leakage and bursts in water pipelines have severe consequences for the environment and the economy. To ensure the reliability of water pipelines, they must be monitored effectively. Wireless Sensor Networks (WSNs have emerged as an effective technology for monitoring critical infrastructure such as water, oil and gas pipelines. In this paper, we present a scalable design and simulation of a water pipeline leakage monitoring system using Radio Frequency IDentification (RFID and WSN technology. The proposed design targets long-distance aboveground water pipelines that have special considerations for maintenance, energy consumption and cost. The design is based on deploying a group of mobile wireless sensor nodes inside the pipeline and allowing them to work cooperatively according to a prescheduled order. Under this mechanism, only one node is active at a time, while the other nodes are sleeping. The node whose turn is next wakes up according to one of three wakeup techniques: location-based, time-based and interrupt-driven. In this paper, mathematical models are derived for each technique to estimate the corresponding energy consumption and memory size requirements. The proposed equations are analyzed and the results are validated using simulation.

  15. 2 Cases of Bullosis Diabeticorum following Long-Distance Journeys by Road: A Report of 2 Cases

    Directory of Open Access Journals (Sweden)

    Fatima Bello

    2012-01-01

    Full Text Available Background. Bullosis diabeticorum is a distinct, spontaneous, noninflammatory, and blistering condition of acral skin that is unique to diabetics. It is rare. Exact aetiopathogenesis is not known, but many attributed peripheral neuropathy as a potent risk factor, others hypothesized the role of trauma, UV light, and nephropathy. Aim. To present cases of bullosis diabeticorum following long-distance journeys by road. Methods. History and physical examinations were done on 2 diabetics who presented with bilateral feet bullae following a long journey. Biopsy of a circumferential area of the bullae including adjoining apparently normal skin was done. Results. Features of peripheral neuropathy were noted. One developed digital gangrene without features of peripheral vascular disease. Culture of aspirate from a bullae yielded Staphylococcus aureus. Tissue biopsy showed hyperkeratotic focally acanthotic pigmented epidermis with subcorneal separation of the granular layer of the epidermis by aggregates of viable and nonviable polymorphs and lymphocytes. There is mild acantholysis of the epidermis, and a fibrocollagenous dermis which is moderately infiltrated by lymphocytes. Conclusion. Long journeys by road is a strong factor in the aetiopathogenesis of bullosis diabeticorum on a background of peripheral neuropathy. Diabetics especially those with peripheral neuropathy should be cautious while traveling long journeys by road.

  16. Concomitant increase in blood plasma levels of immunoreactive hemorphin-7 and beta-endorphin following long distance running.

    Science.gov (United States)

    Glämsta, E L; Mørkrid, L; Lantz, I; Nyberg, F

    1993-11-19

    Hemorphins are endogenous opioids derived by enzymatic degradation of hemoglobin, a protein released in blood plasma during long distance running. We examined levels of beta-endorphin and the heptapeptide hemorphin-7, in heparinized venous blood plasma from 15 sedentary controls (8 males, 7 females) and from 15 age- and sex-matched marathon runners at baseline and after running 42 km or 21 km. Baseline levels of beta-endorphin (range 0.2-4.3 fmol/ml) were neither dependent upon weight, body mass index weight/height, running status nor sex. Baseline levels of hemorphin-7 (range 0.2-6.9 pmol/ml) were lower in women (P < 0.04) and covariated positively with body weight (P = 0.06), explaining lower levels in runners by their lower body weight. Covariation with body mass index was positive, but not significant (P = 0.10), however, here the dependence upon sex appeared stronger (P = 0.014). Running induced significant and correlated increases in hemorphin-7 and beta-endorphin (r = 0.74; P < 0.002), possibly indicating a functional relationship between these two peptides.

  17. 2 Cases of Bullosis Diabeticorum following Long-Distance Journeys by Road: A Report of 2 Cases.

    Science.gov (United States)

    Bello, Fatima; Samaila, O Modupe; Lawal, Yakubu; Nkoro, U Kufre

    2012-01-01

    Background. Bullosis diabeticorum is a distinct, spontaneous, noninflammatory, and blistering condition of acral skin that is unique to diabetics. It is rare. Exact aetiopathogenesis is not known, but many attributed peripheral neuropathy as a potent risk factor, others hypothesized the role of trauma, UV light, and nephropathy. Aim. To present cases of bullosis diabeticorum following long-distance journeys by road. Methods. History and physical examinations were done on 2 diabetics who presented with bilateral feet bullae following a long journey. Biopsy of a circumferential area of the bullae including adjoining apparently normal skin was done. Results. Features of peripheral neuropathy were noted. One developed digital gangrene without features of peripheral vascular disease. Culture of aspirate from a bullae yielded Staphylococcus aureus. Tissue biopsy showed hyperkeratotic focally acanthotic pigmented epidermis with subcorneal separation of the granular layer of the epidermis by aggregates of viable and nonviable polymorphs and lymphocytes. There is mild acantholysis of the epidermis, and a fibrocollagenous dermis which is moderately infiltrated by lymphocytes. Conclusion. Long journeys by road is a strong factor in the aetiopathogenesis of bullosis diabeticorum on a background of peripheral neuropathy. Diabetics especially those with peripheral neuropathy should be cautious while traveling long journeys by road.

  18. Characteristics of Loads of Cattle Stopping for Feed, Water and Rest during Long-Distance Transport in Canada.

    Science.gov (United States)

    Flint, Hannah E; Schwartzkopf-Genswein, Karen S; Bateman, Ken G; Haley, Derek B

    2014-03-05

    This study is the first comprehensive examination of long-haul cattle being transported across Canada and off-loaded for feed, water and rest. A total of 129 truckloads were observed at one of two commercial rest stations near Thunder Bay, Ontario. Data collected included information regarding the truck driver, the trailer, the trip, the animals and animal handling. The majority of the loads stopping were feeder calves (60.94%) while 21.09% were weaned calves, and the remaining 14.84% were market weight cattle. The truck loads surveyed were in transit for, on average, 28.2 ± 5.0 hours before stopping and cattle were rested for an average of 11.2 ± 2.8 hours. These data suggest that loads stopping at the rest station were adhering to the regulations stated in the Health of Animals Act, which outline a maximum of 48 hours in transit before a mandatory stop of at least 5 hours for feed, water and rest. There was a large amount of variability around how well recommendations, such as stocking density were followed. Further research is required to assess how well cattle are coping with long-distance transport under current regulations and industry practices.

  19. The Energy-Efficient Operation Problem of a Freight Train Considering Long-Distance Steep Downhill Sections

    Directory of Open Access Journals (Sweden)

    Xuan Lin

    2017-06-01

    Full Text Available With the energy consumption rising in rail transport, the railway sector is showing increasing interest in the energy-efficient operation of freight trains. Freight trains require more complicated driving strategies than ordinary passenger trains do due to their heavy loads, especially in the long-distance steep downhill (LDSD sections that are very common in freight rail lines in China. This paper studies the energy-efficient operation of a freight train considering LDSD sections. An optimal control model including regenerative and pneumatic braking is developed for the freight train. Then, when a train leaves/enters the LDSD section, we verify the uniqueness of control transitions and discuss the speed profile linkage between LDSD and its adjacent sections, which indicates that the periodic braking should be applied on LDSD sections for optimality. Additionally, given the same running time for the entire journey, our analysis shows that electrical braking-full braking strategy is more energy-efficient than coasting-full braking strategy on LDSD sections. Finally, a numerical algorithm for the optimal driving solution is proposed. The simulation results demonstrate that the driving strategies generated by the proposed algorithm performs better than those from fuzzy predictive control and field operation regarding energy saving.

  20. A proposed scalable design and simulation of wireless sensor network-based long-distance water pipeline leakage monitoring system.

    Science.gov (United States)

    Almazyad, Abdulaziz S; Seddiq, Yasser M; Alotaibi, Ahmed M; Al-Nasheri, Ahmed Y; BenSaleh, Mohammed S; Obeid, Abdulfattah M; Qasim, Syed Manzoor

    2014-02-20

    Anomalies such as leakage and bursts in water pipelines have severe consequences for the environment and the economy. To ensure the reliability of water pipelines, they must be monitored effectively. Wireless Sensor Networks (WSNs) have emerged as an effective technology for monitoring critical infrastructure such as water, oil and gas pipelines. In this paper, we present a scalable design and simulation of a water pipeline leakage monitoring system using Radio Frequency IDentification (RFID) and WSN technology. The proposed design targets long-distance aboveground water pipelines that have special considerations for maintenance, energy consumption and cost. The design is based on deploying a group of mobile wireless sensor nodes inside the pipeline and allowing them to work cooperatively according to a prescheduled order. Under this mechanism, only one node is active at a time, while the other nodes are sleeping. The node whose turn is next wakes up according to one of three wakeup techniques: location-based, time-based and interrupt-driven. In this paper, mathematical models are derived for each technique to estimate the corresponding energy consumption and memory size requirements. The proposed equations are analyzed and the results are validated using simulation.