WorldWideScience

Sample records for american freshwater routing

  1. Extinction rates in North American freshwater fishes, 1900-2010

    Science.gov (United States)

    Burkhead, Noel M.

    2012-01-01

    Widespread evidence shows that the modern rates of extinction in many plants and animals exceed background rates in the fossil record. In the present article, I investigate this issue with regard to North American freshwater fishes. From 1898 to 2006, 57 taxa became extinct, and three distinct populations were extirpated from the continent. Since 1989, the numbers of extinct North American fishes have increased by 25%. From the end of the nineteenth century to the present, modern extinctions varied by decade but significantly increased after 1950 (post-1950s mean = 7.5 extinct taxa per decade). In the twentieth century, freshwater fishes had the highest extinction rate worldwide among vertebrates. The modern extinction rate for North American freshwater fishes is conservatively estimated to be 877 times greater than the background extinction rate for freshwater fishes (one extinction every 3 million years). Reasonable estimates project that future increases in extinctions will range from 53 to 86 species by 2050.

  2. [Latin American malacology. Freshwater mollusks from Argentina].

    Science.gov (United States)

    Rumi, Alejandra; Gregoric, Diego E Gutiérrez; Núñez, Verónica; Darrigran, Gustavo A

    2008-03-01

    A report and an updated list with comments on the species of freshwater molluscs of Argentina which covers an area of 2 777 815 km2 is presented. Distributions of Gastropoda and Bivalvia families, endemic, exotic, invasive as well as entities of sanitary importance are also studied and recommendations on their conservation are provided. Molluscs related to the Del Plata Basin have been thoroughly studied in comparison to others areas of the country. This fauna exhibits relatively the biggest specific richness and keeps its affinity with the fauna of other regions of the basin in areas of Paraguay and Brasil. The 4 500 records of molluscs considered in this paper arise from the study of the collections of Museo Argentino de Ciencias Naturales "Bernardino Rivadavia", Buenos Aires; Museo de La Plata, La Plata and Fundación "Miguel Lillo", Tucumán. These institutions keep very important collections of molluscs in southern South America. Field information has recently been obtained and localities cited by other authors are also included in the data base. Until today, 166 species have been described, 101 belonging to 10 families of Gastropoda and 65 to 7 of Bivalvia. Families with highest specific richness are Lithoglyphidae (22) and Sphaeriidae (25), respectively. The number of endemic species (those present only in Argentina) by family is: Gastropoda: Ampullariidae (1), Cochliopidae (10), Lithoglyphidae (11), Thiariidae (3), Chilinidae (11), Lymnaeidae (2) and Physidae (2?); Bivalvia: Hyriidae (1?); Etheriidae (1?) and Sphaeriidae (10). Families with a distribution that comprise almost the whole country are: the Sphaeriidae and the gastropods Cochliopidae, Chilinidae and Lymnaeidae. Families Erodonidae and Solecurtidae (Bivalvia) were registered in mixohaline environments from Buenos Aires province. Gastropod families Thiaridae and Glacidorbiidae show a very restricted distribution. The rest of the families are present mainly in the center and north of the country

  3. Book review: Ecology of North American freshwater fishes

    Science.gov (United States)

    Bonar, Scott A.

    2014-01-01

    This book will be important in courses for upper undergraduates studying fish ecology or for graduate students. However, it will also be an excellent reference for the fishery manager who asks ‘Why does this fish do that?’. With the wealth of great information contained in Ross’ book, chances are an answer will be found. Review info: Ecology of North American freshwater fishes. Edited by Stephen T. Ross, 2013. ISBN: 978-0520249455, 408 pp.

  4. Operational Evaluatioin of Dynamic Weather Routes at American Airlines

    Science.gov (United States)

    McNally, David; Sheth, Kapil; Gong, Chester; Borchers, Paul; Osborne, Jeff; Keany, Desmond; Scott, Brennan; Smith, Steve; Sahlman, Scott; Lee, Chuhan; Cheng, Jinn-Hwei

    2013-01-01

    Dynamic Weather Routes (DWR) is a search engine that continuously and automatically analyzes inflight aircraft in en route airspace and proposes simple route amendments for more efficient routes around convective weather while considering sector congestion, traffic conflicts, and active Special Use Airspace. NASA and American Airlines (AA) are conducting an operational trial of DWR at the AA System Operations Center in Fort Worth, TX. The trial includes only AA flights in Fort Worth Center airspace. Over the period from July 31, 2012 through August 31, 2012, 45% of routes proposed by DWR and evaluated by AA users - air traffic control coordinators and flight dispatchers - were rated as acceptable as proposed or with some modifications. The wind-corrected potential flying time savings for these acceptable routes totals 470 flying min, and results suggest another 1,500 min of potential savings for flights not evaluated due to staffing limitations. A sector congestion analysis shows that in only two out of 83 DWR routes rated acceptable by AA staff were the flights predicted to fly through a congested sector inside of 30 min downstream of present position. This shows that users considered sector congestion data provided by DWR automation and in nearly all cases did not accept routes through over-capacity sectors. It is estimated that 12 AA flights were given reroute clearances as a direct result of DWR for a total savings of 67 flying min.

  5. Conservation status of imperiled north American freshwater and diadromous fishes

    Science.gov (United States)

    Jelks, H.L.; Walsh, S.J.; Burkhead, N.M.; Contreras-Balderas, Salvador; Diaz-Pardo, E.; Hendrickson, D.A.; Lyons, J.; Mandrak, N.E.; McCormick, F.; Nelson, Joseph S.; Platania, S.P.; Porter, B.A.; Renaud, C.B.; Schmitter-Soto, J. J.; Taylor, E.B.; Warren, M.L., Jr.

    2008-01-01

    This is the third compilation of imperiled (i.e., endangered, threatened, vulnerable) plus extinct freshwater and diadromous fishes of North America prepared by the American Fisheries Society's Endangered Species Committee. Since the last revision in 1989, imperilment of inland fishes has increased substantially. This list includes 700 extant taxa representing 133 genera and 36 families, a 92% increase over the 364 listed in 1989. The increase reflects the addition of distinct populations, previously non-imperiled fishes, and recently described or discovered taxa. Approximately 39% of described fish species of the continent are imperiled. There are 230 vulnerable, 190 threatened, and 280 endangered extant taxa, and 61 taxa presumed extinct or extirpated from nature. Of those that were imperiled in 1989, most (89%) are the same or worse in conservation status; only 6% have improved in status, and 5% were delisted for various reasons. Habitat degradation and nonindigenous species are the main threats to at-risk fishes, many of which are restricted to small ranges. Documenting the diversity and status of rare fishes is a critical step in identifying and implementing appropriate actions necessary for their protection and management.

  6. UNFAIR COMPETITION? AMERICAN AND JAPANESE AIRLINES TRANSPACIFIC ROUTE RIVALRIES, 1946—1971

    Directory of Open Access Journals (Sweden)

    Douglas Karsner

    2007-01-01

    Full Text Available This article examines the changing nature of competition between American and Japanese airlines for transpacific passenger and cargo routes during the formative early postwar era. It focuses on the period from 1946, when the US government first certified Northwest and Pan American airlines to fly to Japan, to 1971, as the age of mass air travel took off amidst major economic changes such as the Nixon Shocks. Utilizing both American and Japanese sources, the author argues that a complex mixture of economic and diplomatic factors shaped American and Japanese airlines’ transpacific route rivalries.

  7. The cold-water connection: Bergmann's rule in North American freshwater fishes.

    Science.gov (United States)

    Rypel, Andrew L

    2014-01-01

    Understanding general rules governing macroecological body size variations is one of the oldest pursuits in ecology. However, this science has been dominated by studies of terrestrial vertebrates, spurring debate over the validity of such rules in other taxonomic groups. Here, relationships between maximum body size and latitude, temperature, and elevation were evaluated for 29 North American freshwater fish species. Bergmann's rule (i.e., that body size correlates positively with latitude and negatively with temperature) was observed in 38% of species, converse Bergmann's rule (that body size correlates negatively with latitude and positively with temperature) was observed in 34% of species, and 28% of species showed no macroecological body size relationships. Most notably, every species that expressed Bergmann's rule was a cool- or cold-water species while every species that expressed converse Bergmann's rule was a warm-water species, highlighting how these patterns are likely connected to species thermal niches. This study contradicts previous research suggesting Bergmann's rule does not apply to freshwater fishes, and is congruent with an emerging paradigm of variable macroecological body size patterns in poikilotherms. PMID:24334744

  8. Freshwater on the route of hominids "out of Africa" during the last interglacial revealed by U-Th in northern Red Sea fossil reefs

    Science.gov (United States)

    Lazar, B.; Stein, M.; Agnon, A.; Shaked, Y.

    2012-04-01

    The migration of Anatomically Modern Hominids (AMH) "out of Africa" is a fundamental problem in the study of human culture concerning that the route passed through the presently hyperarid deserts surrounding the Red Sea. Here, we outline the evidence for significant presence of freshwater in a well developed phreatic coastal aquifer along the Red Sea shores during the last interglacial period. The fringing coral reefs were tectonically uplifted through the freshwater lens resulting in extensive recrystallization of reef framework from the primary aragonite into calcite. We developed a novel open-system U-Th dating methodology that enabled us estimating two ages for the calcitic reef terrace: 1. The original age of the reef terrace, deposited at ~190 ka BP; and 2. the time of freshwater recrystallization (from the primary aragonite into calcite) at ~140 ka BP. The age of freshwater recrystallization is consistent with other geological lines of evidence placing the time of AMH migration "out of Africa" at the onset of the last interglacial. It is likely therefore that during that time the hyperarid Red Sea area was wetter than today facilitating the migration of AMH to Europe and Asia.

  9. [Studies on Latin American freshwater macroinvertebrates: recent advances and future directions].

    Science.gov (United States)

    Ramírez, Alonso; Gutiérrez-Fonseca, Pablo E

    2014-04-01

    Latin America is an active scientific research area, in particular with respect to the study of freshwater macroinvertebrates. The present serves as an introduction to a special issue that highlights recent research projects on macroinvertebrates in Latin America. As part of this introduction, we conducted a literature analysis of the last 14 years of publications from the region that highlights the steady increase in publications on macroinvertebrates. Most studies from 2000-2013 were conducted in Brazil, Colombia, Argentina, and Costa Rica, and were focused on taxonomy and different issues related to biodiversity and distribution. There was a tendency for the use of local low-impact journals, but high impact publications were also found. This special issue contributes with 18 studies conducted in eight different countries. Two major topics are covered in the special issue, the ecology and natural history of aquatic macroinvertebrates and their use in the evaluation of anthropogenic impacts to aquatic ecosystems. Based on the literature review and contributions included in the issue, we discuss research needs for the region. Identified needs include: (1) to continue emphasizing taxonomic research, (2) assess mechanisms responsible for changes in biodiversity, (3) assess the role of macroinvertebrates in ecosystem processes and function, (4) improve biomonitoring efforts beyond unimetric indices, (5) the need for an ecosystem perspective, and (6) establishing long-term studies. This special issue is an initial effort to advance our knowledge on freshwater macroinvertebrates in Latin America.

  10. Two new species of freshwater flatworms (Platyhelminthes: Tricladida: Continenticola) from South American caves.

    Science.gov (United States)

    Souza, Stella; Morais, Ana Laura; Bichuette, Maria Elina; Leal-Zanchet, Ana

    2016-01-01

    The diversity of freshwater triclads in the Neotropical region is considered to be low, but extensive areas of South America remain almost unexplored. Herein we describe two cave-dwelling, new species of Girardia, one from a transition zone of the Cerrado and Caatinga phytophysiognomies and the other from the Cerrado phytophysiognomy. The species from the Cerrado-Caatinga transition is a troglobite, eyeless and whitish; the species from the Cerrado area is possibly a troglophile, since it shows heavily pigmented body and eyes. Each species is easily recognized by a unique combination of features in its external morphology and copulatory apparatus. The two new species of Girardia show a restricted distribution, even the troglophile, and occur in caves without legal protection. Therefore, they must be considered as vulnerable organisms in a conservation context. PMID:27394369

  11. North American Water Program (NAWP): A Vision to Address North America's Freshwater Sustainability Challenges

    Science.gov (United States)

    Belvedere, D. R.; Houser, P. R.; Schiffer, R. A.; Entin, J. K.

    2013-12-01

    Dramatically changing climates has had an indelible impact on North America's water crisis; the rapid melting of glaciers has profound implications for the sustainability of Canada's rivers. However, projective increases in water demand from increasing population, industrial energy, and agriculture needs may have four times more impact on the water supply-demand imbalance than climate change. Reliable prediction of hydrologic change and extremes is of critical importance for policy and decision makers to adapt to these future water challenges. However, the models that we use to understand and forecast water availability, flooding, and drought are simply not up to the task of addressing our most pressing societal issues and national security. We need a decisive and coordinative effort to systematically improve water cycle prediction skill, coupled with reliable methodologies to translate those predictions into actionable water supply and quality information to support sustainable water management - this is a primary motivation for the proposed North American Water Program (NAWP). To decisively address these challenges, we recommend that NAWP coalesce an interdisciplinary, international and interagency effort to make significant contributions to continental-to-decision-scale hydroclimate science and solutions. By entraining, integrating and coordinating the vast array of interdisciplinary observationable and prediction resources available, NAWP will significantly advance skill in predicting, assessing, and managing variability and changes in North American water resources, as an integral part of the global climate system. We adopt three challenges to organize NAWP efforts. The first deals with developing a scientific basis and tools for mitigating and adapting to changes in the water supply-demand balance. The second challenge is benchmarking; to use incomplete and uncertain observations to assess water storage and quality dynamics, and to characterize the

  12. Traffic effects on bird counts on North American Breeding Bird Survey routes

    Science.gov (United States)

    Griffith, Emily H.; Sauer, John R.; Royle, J. Andrew

    2010-01-01

    The North American Breeding Bird Survey (BBS) is an annual roadside survey used to estimate population change in >420 species of birds that breed in North America. Roadside sampling has been criticized, in part because traffic noise can interfere with bird counts. Since 1997, data have been collected on the numbers of vehicles that pass during counts at each stop. We assessed the effect of traffic by modeling total vehicles as a covariate of counts in hierarchical Poisson regression models used to estimate population change. We selected species for analysis that represent birds detected at low and high abundance and birds with songs of low and high frequencies. Increases in vehicle counts were associated with decreases in bird counts in most of the species examined. The size and direction of these effects remained relatively constant between two alternative models that we analyzed. Although this analysis indicated only a small effect of incorporating traffic effects when modeling roadside counts of birds, we suggest that continued evaluation of changes in traffic at BBS stops should be a component of future BBS analyses.

  13. Phylogeographic Analysis of Blastomyces dermatitidis and Blastomyces gilchristii Reveals an Association with North American Freshwater Drainage Basins

    Science.gov (United States)

    McTaggart, Lisa R.; Brown, Elizabeth M.; Richardson, Susan E.

    2016-01-01

    Blastomyces dermatitidis and Blastomyces gilchristii are dimorphic fungal pathogens that cause serious pulmonary and systemic infections in humans. Although their natural habitat is in the environment, little is known about their specific ecologic niche(s). Here, we analyzed 25 microsatellite loci from 169 strains collected from various regions throughout their known endemic range in North America, representing the largest and most geographically diverse collection of isolates studied to date. Genetic analysis of multilocus microsatellite data divided the strains into four populations of B. dermatitidis and four populations of B. gilchristii. B. dermatitidis isolates were recovered from areas throughout North America, while the B. gilchristii strains were restricted to Canada and some northern US states. Furthermore, the populations of both species were associated with major freshwater drainage basins. The four B. dermatitidis populations were partitioned among (1) the Nelson River drainage basin, (2) the St. Lawrence River and northeast Atlantic Ocean Seaboard drainage basins, (3) the Mississippi River System drainage basin, and (4) the Gulf of Mexico Seaboard and southeast Atlantic Ocean Seaboard drainage basins. A similar partitioning of the B. gilchristii populations was observed among the more northerly drainage basins only. These associations suggest that the ecologic niche where the sexual reproduction, growth, and dispersal of B. dermatitidis and B. gilchristii occur is intimately linked to freshwater systems. For most populations, sexual reproduction was rare enough to produce significant linkage disequilibrium among loci but frequent enough that mating-type idiomorphic ratios were not skewed from 1:1. Furthermore, the evolutionary divergence of B. dermatitidis and B. gilchristii was estimated at 1.9 MYA during the Pleistocene epoch. We suggest that repeated glaciations during the Pleistocene period and resulting biotic refugia may have provided the

  14. Phylogeographic Analysis of Blastomyces dermatitidis and Blastomyces gilchristii Reveals an Association with North American Freshwater Drainage Basins.

    Science.gov (United States)

    McTaggart, Lisa R; Brown, Elizabeth M; Richardson, Susan E

    2016-01-01

    Blastomyces dermatitidis and Blastomyces gilchristii are dimorphic fungal pathogens that cause serious pulmonary and systemic infections in humans. Although their natural habitat is in the environment, little is known about their specific ecologic niche(s). Here, we analyzed 25 microsatellite loci from 169 strains collected from various regions throughout their known endemic range in North America, representing the largest and most geographically diverse collection of isolates studied to date. Genetic analysis of multilocus microsatellite data divided the strains into four populations of B. dermatitidis and four populations of B. gilchristii. B. dermatitidis isolates were recovered from areas throughout North America, while the B. gilchristii strains were restricted to Canada and some northern US states. Furthermore, the populations of both species were associated with major freshwater drainage basins. The four B. dermatitidis populations were partitioned among (1) the Nelson River drainage basin, (2) the St. Lawrence River and northeast Atlantic Ocean Seaboard drainage basins, (3) the Mississippi River System drainage basin, and (4) the Gulf of Mexico Seaboard and southeast Atlantic Ocean Seaboard drainage basins. A similar partitioning of the B. gilchristii populations was observed among the more northerly drainage basins only. These associations suggest that the ecologic niche where the sexual reproduction, growth, and dispersal of B. dermatitidis and B. gilchristii occur is intimately linked to freshwater systems. For most populations, sexual reproduction was rare enough to produce significant linkage disequilibrium among loci but frequent enough that mating-type idiomorphic ratios were not skewed from 1:1. Furthermore, the evolutionary divergence of B. dermatitidis and B. gilchristii was estimated at 1.9 MYA during the Pleistocene epoch. We suggest that repeated glaciations during the Pleistocene period and resulting biotic refugia may have provided the

  15. Phylogeographic Analysis of Blastomyces dermatitidis and Blastomyces gilchristii Reveals an Association with North American Freshwater Drainage Basins.

    Directory of Open Access Journals (Sweden)

    Lisa R McTaggart

    Full Text Available Blastomyces dermatitidis and Blastomyces gilchristii are dimorphic fungal pathogens that cause serious pulmonary and systemic infections in humans. Although their natural habitat is in the environment, little is known about their specific ecologic niche(s. Here, we analyzed 25 microsatellite loci from 169 strains collected from various regions throughout their known endemic range in North America, representing the largest and most geographically diverse collection of isolates studied to date. Genetic analysis of multilocus microsatellite data divided the strains into four populations of B. dermatitidis and four populations of B. gilchristii. B. dermatitidis isolates were recovered from areas throughout North America, while the B. gilchristii strains were restricted to Canada and some northern US states. Furthermore, the populations of both species were associated with major freshwater drainage basins. The four B. dermatitidis populations were partitioned among (1 the Nelson River drainage basin, (2 the St. Lawrence River and northeast Atlantic Ocean Seaboard drainage basins, (3 the Mississippi River System drainage basin, and (4 the Gulf of Mexico Seaboard and southeast Atlantic Ocean Seaboard drainage basins. A similar partitioning of the B. gilchristii populations was observed among the more northerly drainage basins only. These associations suggest that the ecologic niche where the sexual reproduction, growth, and dispersal of B. dermatitidis and B. gilchristii occur is intimately linked to freshwater systems. For most populations, sexual reproduction was rare enough to produce significant linkage disequilibrium among loci but frequent enough that mating-type idiomorphic ratios were not skewed from 1:1. Furthermore, the evolutionary divergence of B. dermatitidis and B. gilchristii was estimated at 1.9 MYA during the Pleistocene epoch. We suggest that repeated glaciations during the Pleistocene period and resulting biotic refugia may have

  16. First DNA Barcode Reference Library for the Identification of South American Freshwater Fish from the Lower Paraná River.

    Science.gov (United States)

    Díaz, Juan; Villanova, Gabriela Vanina; Brancolini, Florencia; Del Pazo, Felipe; Posner, Victoria Maria; Grimberg, Alexis; Arranz, Silvia Eda

    2016-01-01

    Valid fish species identification is essential for biodiversity conservation and fisheries management. Here, we provide a sequence reference library based on mitochondrial cytochrome c oxidase subunit I for a valid identification of 79 freshwater fish species from the Lower Paraná River. Neighbour-joining analysis based on K2P genetic distances formed non-overlapping clusters for almost all species with a ≥99% bootstrap support each. Identification was successful for 97.8% of species as the minimum genetic distance to the nearest neighbour exceeded the maximum intraspecific distance in all these cases. A barcoding gap of 2.5% was apparent for the whole data set with the exception of four cases. Within-species distances ranged from 0.00% to 7.59%, while interspecific distances varied between 4.06% and 19.98%, without considering Odontesthes species with a minimum genetic distance of 0%. Sequence library validation was performed by applying BOLDs BIN analysis tool, Poisson Tree Processes model and Automatic Barcode Gap Discovery, along with a reliable taxonomic assignment by experts. Exhaustive revision of vouchers was performed when a conflicting assignment was detected after sequence analysis and BIN discordance evaluation. Thus, the sequence library presented here can be confidently used as a benchmark for identification of half of the fish species recorded for the Lower Paraná River. PMID:27442116

  17. First DNA Barcode Reference Library for the Identification of South American Freshwater Fish from the Lower Paraná River

    Science.gov (United States)

    Brancolini, Florencia; del Pazo, Felipe; Posner, Victoria Maria; Grimberg, Alexis; Arranz, Silvia Eda

    2016-01-01

    Valid fish species identification is essential for biodiversity conservation and fisheries management. Here, we provide a sequence reference library based on mitochondrial cytochrome c oxidase subunit I for a valid identification of 79 freshwater fish species from the Lower Paraná River. Neighbour-joining analysis based on K2P genetic distances formed non-overlapping clusters for almost all species with a ≥99% bootstrap support each. Identification was successful for 97.8% of species as the minimum genetic distance to the nearest neighbour exceeded the maximum intraspecific distance in all these cases. A barcoding gap of 2.5% was apparent for the whole data set with the exception of four cases. Within-species distances ranged from 0.00% to 7.59%, while interspecific distances varied between 4.06% and 19.98%, without considering Odontesthes species with a minimum genetic distance of 0%. Sequence library validation was performed by applying BOLDs BIN analysis tool, Poisson Tree Processes model and Automatic Barcode Gap Discovery, along with a reliable taxonomic assignment by experts. Exhaustive revision of vouchers was performed when a conflicting assignment was detected after sequence analysis and BIN discordance evaluation. Thus, the sequence library presented here can be confidently used as a benchmark for identification of half of the fish species recorded for the Lower Paraná River. PMID:27442116

  18. Field and laboratory guide to freshwater cyanobacteria harmful algal blooms for Native American and Alaska Native communities

    Science.gov (United States)

    Rosen, Barry H.; Ann St. Amand

    2015-01-01

    Cyanobacteria can produce toxins and form harmful algal blooms. The Native American and Alaska Native communities that are dependent on subsistence fishing have an increased risk of exposure to these cyanotoxins. It is important to recognize the presence of an algal bloom in a waterbody and to distinguish a potentially toxic harmful algal bloom from a non-toxic bloom. This guide provides field images that show cyanobacteria blooms, some of which can be toxin producers, as well as other non-toxic algae blooms and floating plants that might be confused with algae. After recognition of a potential toxin-producing cyanobacterial bloom in the field, the type(s) of cyanobacteria present needs to be identified. Species identification, which requires microscopic examination, may help distinguish a toxin-producer from a non-toxin producer. This guide also provides microscopic images of the common cyanobacteria that are known to produce toxins, as well as images of algae that form blooms but do not produce toxins.

  19. Freshwater Wetlands.

    Science.gov (United States)

    Naturescope, 1986

    1986-01-01

    Provides descriptions about freshwater wetlands, such as marshes, swamps, and bogs. Contains three learning activities which deal with unusual wetland plants, the animals and plants in a typical marsh, and the effects of a draught on a swamp. Included are reproducible handouts and worksheets for two of the activities. (TW)

  20. Gastric nematode diversity between estuarine and inland freshwater populations of the American alligator (Alligator mississippiensis, daudin 1802, and the prediction of intermediate hosts

    Directory of Open Access Journals (Sweden)

    Marisa Tellez

    2014-12-01

    Full Text Available We examined the variation of stomach nematode intensity and species richness of Alligator mississippiensis from coastal estuarine and inland freshwater habitats in Florida and Georgia, and integrated prey content data to predict possible intermediate hosts. Nematode parasitism within inland freshwater inhabiting populations was found to have a higher intensity and species richness than those inhabiting coastal estuarine systems. This pattern potentially correlates with the difference and diversity of prey available between inland freshwater and coastal estuarine habitats. Increased consumption of a diverse array of prey was also correlated with increased nematode intensity in larger alligators. Parasitic nematodes Dujardinascaris waltoni, Brevimulticaecum tenuicolle, Ortleppascaris antipini, Goezia sp., and Contracaecum sp. were present in alligators from both habitat types. Dujardinascaris waltoni, B. tenuicolle, and O. antipini had a significantly higher abundance among inland inhabiting alligators than hosts from estuarine populations. Our findings also suggest that host specific nematode parasites of alligators may have evolved to infect multiple intermediate hosts, particularly fishes, crabs, and turtles, perhaps in response to the opportunistic predatory behaviors of alligators.

  1. Freshwater Ecosystem Conservation: Towards a Comprehensive Water Resources Management Strategy

    OpenAIRE

    Enrique Bucher; Gonzalo Castro; Vinio Floris

    1997-01-01

    Conservation of freshwater biodiversity has been seriously neglected throughout the world, and entire ecosystems are threatened with extinction. Unfortunately, freshwater sustainability issues do not appear to be a primary consideration in the planning and implementation of water use projects, nor in the allocation of use permits. This paper discusses the value and function of Latin American freshwater ecosystems and gives a comprehensive approach to developing a sustainable water resources m...

  2. Imperiled Freshwater and Diadromous Fishes of North America

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — List of imperiled freshwater and diadromous fishes of North America as determined by the 2008 American Fisheries Society (AFS) Endangered Species Committee (ESC) on...

  3. Torch Route Twist

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    San Francisco changes Olympic flame route due to security fears The city of San Francisco,the only North American stop for the 2008 Beijing Olympic torch,surprised thousands of supporters,demon- strators and visitors on April 9,by com- pletely changing the planned torch route at the last minute without notification. As scheduled,the torch was expected to start from the McCovey Cove in the south- east of the city at 1:00 p.m.before heading along the waterfront northbound to famous tourist spot Fisherman’s Wharf and finally

  4. Transfers to freshwater biota

    International Nuclear Information System (INIS)

    It remains important to monitor the fate of radionuclides, particularly in environmental compartments that comprise human pathways. Therefore, an extensive literature survey has been conducted to compile available data on the transfer of radionuclides and their analogues to edible freshwater biota. Focus was placed on compilation of steady state transfer parameters for two freshwater pathways, including water-to-biota and sediment-to-biota. In general, although in many cases, extensive data were available for fishes and invertebrates, relatively fewer data were available for freshwater primary producers, amphibians and reptiles. To fill in these gaps, data were also compiled on the internal partitioning of elements in the body with respect to tissue masses, which could be used to estimate radionuclide concentrations between compartments in the body. (author)

  5. Routing Proposals for Multipath Interdomain Routing

    OpenAIRE

    Bilal, Sardar M.; Dilber, Muhammad Naveed; Khan, Atta ur Rehman

    2013-01-01

    Internet is composed of numbers of independent autonomous systems. BGP is used to disseminate reachability information and establishing path between autonomous systems. Each autonomous system is allowed to select a single route to a destination and then export the selected route to its neighbors. The selection of single best route imposes restrictions on the use of alternative paths during interdomain link failure and thus, incurred packet loss. Packet loss still occurs even when multiple pat...

  6. Visualizing Internet routing changes.

    Science.gov (United States)

    Lad, Mohit; Massey, Dan; Zhang, Lixia

    2006-01-01

    Today's Internet provides a global data delivery service to millions of end users and routing protocols play a critical role in this service. It is important to be able to identify and diagnose any problems occurring in Internet routing. However, the Internet's sheer size makes this task difficult. One cannot easily extract out the most important or relevant routing information from the large amounts of data collected from multiple routers. To tackle this problem, we have developed Link-Rank, a tool to visualize Internet routing changes at the global scale. Link-Rank weighs links in a topological graph by the number of routes carried over each link and visually captures changes in link weights in the form of a topological graph with adjustable size. Using Link-Rank, network operators can easily observe important routing changes from massive amounts of routing data, discover otherwise unnoticed routing problems, understand the impact of topological events, and infer root causes of observed routing changes.

  7. Routing in opportunistic networks

    CERN Document Server

    Dhurandher, Sanjay; Anpalagan, Alagan; Vasilakos, Athanasios

    2013-01-01

    This book provides a comprehensive guide to selected topics, both ongoing and emerging, in routing in OppNets. The book is edited by worldwide technical leaders, prolific researchers and outstanding academics, Dr. Isaac Woungang and co-editors, Dr. Sanjay Kumar Dhurandher, Prof. Alagan Anpalagan and Prof. Athanasios Vasilakos. Consisting of contributions from well known and high profile researchers and scientists in their respective specialties, the main topics that are covered in this book include mobility and routing, social-aware routing, context-based routing, energy-aware routing, incentive-aware routing, stochastic routing, modeling of intermittent connectivity, in both infrastructure and infrastructure-less OppNets. Key Features: Discusses existing and emerging techniques for routing in infrastructure and infrastructure-less OppNets. Provides a unified covering of otherwise disperse selected topics on routing in infrastructure and infrastructure-less OppNets.  Includes a set of PowerPoint slides and g...

  8. Arctic freshwater synthesis: Introduction

    Science.gov (United States)

    Prowse, T.; Bring, A.; Mârd, J.; Carmack, E.

    2015-11-01

    In response to a joint request from the World Climate Research Program's Climate and Cryosphere Project, the International Arctic Science Committee, and the Arctic Council's Arctic Monitoring and Assessment Program, an updated scientific assessment has been conducted of the Arctic Freshwater System (AFS), entitled the Arctic Freshwater Synthesis (AFSΣ). The major reason for joint request was an increasing concern that changes to the AFS have produced, and could produce even greater, changes to biogeophysical and socioeconomic systems of special importance to northern residents and also produce extra-Arctic climatic effects that will have global consequences. Hence, the key objective of the AFSΣ was to produce an updated, comprehensive, and integrated review of the structure and function of the entire AFS. The AFSΣ was organized around six key thematic areas: atmosphere, oceans, terrestrial hydrology, terrestrial ecology, resources and modeling, and the review of each coauthored by an international group of scientists and published as separate manuscripts in this special issue of Journal of Geophysical Research-Biogeosciences. This AFSΣ—Introduction reviews the motivations for, and foci of, previous studies of the AFS, discusses criteria used to define the domain of the AFS, and details key characteristics of the definition adopted for the AFSΣ.

  9. Routing on Metacyclic Graphs

    Institute of Scientific and Technical Information of China (English)

    Wenjun Xiao

    2002-01-01

    Wu, Lakshmivarahan and Dhall[5] recently described a deterministic, distributed routing scheme for some special classes of metacyclic graphs. However they have no proof of correctness that the scheme is a shortest path routing algorithm. In the note we give a suboptimal, deterministic routing algorithm.

  10. Reclaiming freshwater sustainability in the Cadillac Desert

    Science.gov (United States)

    Sabo, John L.; Sinha, Tushar; Bowling, Laura C.; Schoups, Gerrit H.W.; Wallender, Wesley W.; Campana, Michael E.; Cherkauer, Keith A.; Fuller, Pam L.; Graf, William L.; Hopmans, Jan W.; Kominoski, John S.; Taylor, Carissa; Trimble, Stanley W.; Webb, Robert H.; Wohl, Ellen E.

    2010-01-01

    Increasing human appropriation of freshwater resources presents a tangible limit to the sustainability of cities, agriculture, and ecosystems in the western United States. Marc Reisner tackles this theme in his 1986 classic Cadillac Desert: The American West and Its Disappearing Water. Reisner's analysis paints a portrait of region-wide hydrologic dysfunction in the western United States, suggesting that the storage capacity of reservoirs will be impaired by sediment infilling, croplands will be rendered infertile by salt, and water scarcity will pit growing desert cities against agribusiness in the face of dwindling water resources. Here we evaluate these claims using the best available data and scientific tools. Our analysis provides strong scientific support for many of Reisner's claims, except the notion that reservoir storage is imminently threatened by sediment. More broadly, we estimate that the equivalent of nearly 76% of streamflow in the Cadillac Desert region is currently appropriated by humans, and this figure could rise to nearly 86% under a doubling of the region's population. Thus, Reisner's incisive journalism led him to the same conclusions as those rendered by copious data, modern scientific tools, and the application of a more genuine scientific method. We close with a prospectus for reclaiming freshwater sustainability in the Cadillac Desert, including a suite of recommendations for reducing region-wide human appropriation of streamflow to a target level of 60%.

  11. Climate and local abundance in freshwater fishes.

    Science.gov (United States)

    Knouft, Jason H; Anthony, Melissa M

    2016-06-01

    Identifying factors regulating variation in numbers of individuals among populations across a species' distribution is a fundamental goal in ecology. A common prediction, often referred to as the abundant-centre hypothesis, suggests that abundance is highest near the centre of a species' range. However, because of the primary focus on the geographical position of a population, this framework provides little insight into the environmental factors regulating local abundance. While range-wide variation in population abundance associated with environmental conditions has been investigated in terrestrial species, the relationship between climate and local abundance in freshwater taxa across species' distributions is not well understood. We used GIS-based temperature and precipitation data to determine the relationships between climatic conditions and range-wide variation in local abundance for 19 species of North American freshwater fishes. Climate predicted a portion of the variation in local abundance among populations for 18 species. In addition, the relationship between climatic conditions and local abundance varied among species, which is expected as lineages partition the environment across geographical space. The influence of local habitat quality on species persistence is well documented; however, our results also indicate the importance of climate in regulating population sizes across a species geographical range, even in aquatic taxa. PMID:27429769

  12. State alternative route designations

    Energy Technology Data Exchange (ETDEWEB)

    1989-07-01

    Pursuant to the Hazardous Materials Transportation Act (HMTA), the Department of Transportation (DOT) has promulgated a comprehensive set of regulations regarding the highway transportation of high-level radioactive materials. These regulations, under HM-164 and HM-164A, establish interstate highways as the preferred routes for the transportation of radioactive materials within and through the states. The regulations also provide a methodology by which a state may select alternative routes. First,the state must establish a ``state routing agency,`` defined as an entity authorized to use the state legal process to impose routing requirements on carriers of radioactive material (49 CFR 171.8). Once identified, the state routing agency must select routes in accordance with Large Quantity Shipments of Radioactive Materials or an equivalent routing analysis. Adjoining states and localities should be consulted on the impact of proposed alternative routes as a prerequisite of final route selection. Lastly, the states must provide written notice of DOT of any alternative route designation before the routes are deemed effective.

  13. State alternative route designations

    Energy Technology Data Exchange (ETDEWEB)

    1989-07-01

    Pursuant to the Hazardous Materials Transportation Act (HMTA), the Department of Transportation (DOT) has promulgated a comprehensive set of regulations regarding the highway transportation of high-level radioactive materials. These regulations, under HM-164 and HM-164A, establish interstate highways as the preferred routes for the transportation of radioactive materials within and through the states. The regulations also provide a methodology by which a state may select alternative routes. First,the state must establish a state routing agency,'' defined as an entity authorized to use the state legal process to impose routing requirements on carriers of radioactive material (49 CFR 171.8). Once identified, the state routing agency must select routes in accordance with Large Quantity Shipments of Radioactive Materials or an equivalent routing analysis. Adjoining states and localities should be consulted on the impact of proposed alternative routes as a prerequisite of final route selection. Lastly, the states must provide written notice of DOT of any alternative route designation before the routes are deemed effective.

  14. Phylogenetic diversity of freshwater picocyanobacteria

    OpenAIRE

    Callieri, Cristiana; Coci, Manuela

    2012-01-01

    Picocyanobacteria are photosynthetic prokaryotes, coccoid or rod-shaped, with a cell diameter < 2 ?m. They are common in lakes and oceans, and abundant across a wide spectrum of trophic conditions (Callieri et al 2012). The dominant genus of freshwater picocyanobacteria is Synechococcus. Analysis of 16S rRNA gene of freshwater Synechococcus showed its polyphyletic origin, requiring better insights in the present classification of the genus and possibly a revision. We isolated more than 40 pic...

  15. Investigating the impact of Lake Agassiz drainage routes on the 8.2 ka cold event with climate modeling

    Directory of Open Access Journals (Sweden)

    Y.-X. Li

    2009-03-01

    Full Text Available The 8.2 ka event is the most prominent abrupt climate change in the Holocene and is widely believed to result from catastrophic drainage of proglacial lakes Agassiz and Ojibway (LAO that routed through the Hudson Bay and the Labrador Sea into the North Atlantic Ocean, and perturbed Atlantic meridional overturning circulation (MOC. One key assumption of this triggering mechanism is that the LAO freshwater drainage was spread over the Labrador Sea. Recent data, however, show no evidence of lowered δ18O values from the open Labrador Sea around 8.2 ka. Instead, negative δ18O anomalies are found close to the east coast of North America, extending as far south as Cape Hatteras, North Carolina, suggesting that the freshwater drainage was probably confined to a long stretch of continental shelf before fully mixing with North Atlantic Ocean water. Here we conduct a sensitivity study that examines the effects of this southerly drainage route on the 8.2 ka event with the ECBilt-CLIO-VECODE model. Hosing experiments of four different routing scenarios, where freshwater was introduced to the Labrador Sea in the northerly route (R1 and to three different locations (Grand Banks – R2, George Bank – R3, and Cape Hatteras – R4 on the southerly route, were performed with 0.45 m sea-level equivalent (SLE, 0.90 m SLE, and 1.35 m SLE of freshwater introduced over 5 years to investigate the routing effects on model responses. The modelling results show that a southerly drainage route is plausible but generally yields reduced climatic consequences in comparison to those of a northerly route. This finding implies that more freshwater would be required for a southerly route than for a northerly route to produce the same climate anomaly.

  16. Routing and scheduling problems

    DEFF Research Database (Denmark)

    Reinhardt, Line Blander

    of a connection between two locations. This could be an urban bus schedule where busses are routed and this routing creates a bus schedule which the passengers between locations use. In this thesis various routing and scheduling problems will be presented. The topics covered will be routing from an origin...... set cost making the cost of the individual vehicle routes inter-dependant. Depending on the problem type, the size of the problems and time available for solving, different solution methods can be applicable. In this thesis both heuristic methods and several exact methods are investigated depending...... on the problems needed to be solved. The solution methods applied to the problems cover dynamic programming for multi constrained shortest paths, Branch-and-cut for liner shipping, Simulated annealing for transporting assisted passengers in airports, branch-cut-and-price for vehicle routing with time windows...

  17. Traffic-Adaptive Routing

    OpenAIRE

    Kammenhuber, Nils

    2011-01-01

    Despite the bursty and highly volatile traffic, routing in the Internet today is optimised only on coarse time scales, as load-adaptive routing is known to induce performance deterioration by causing massive oscillations. We describe ReplEx, an universally applicable distributed algorithm for dynamic routing/traffic engineering, which is based on game theory. We show through extensive realistic simulations that ReplEx does not oscillate, and that it achieves performance gains comparable to tr...

  18. Contact Graph Routing

    Science.gov (United States)

    Burleigh, Scott C.

    2011-01-01

    Contact Graph Routing (CGR) is a dynamic routing system that computes routes through a time-varying topology of scheduled communication contacts in a network based on the DTN (Delay-Tolerant Networking) architecture. It is designed to enable dynamic selection of data transmission routes in a space network based on DTN. This dynamic responsiveness in route computation should be significantly more effective and less expensive than static routing, increasing total data return while at the same time reducing mission operations cost and risk. The basic strategy of CGR is to take advantage of the fact that, since flight mission communication operations are planned in detail, the communication routes between any pair of bundle agents in a population of nodes that have all been informed of one another's plans can be inferred from those plans rather than discovered via dialogue (which is impractical over long one-way-light-time space links). Messages that convey this planning information are used to construct contact graphs (time-varying models of network connectivity) from which CGR automatically computes efficient routes for bundles. Automatic route selection increases the flexibility and resilience of the space network, simplifying cross-support and reducing mission management costs. Note that there are no routing tables in Contact Graph Routing. The best route for a bundle destined for a given node may routinely be different from the best route for a different bundle destined for the same node, depending on bundle priority, bundle expiration time, and changes in the current lengths of transmission queues for neighboring nodes; routes must be computed individually for each bundle, from the Bundle Protocol agent's current network connectivity model for the bundle s destination node (the contact graph). Clearly this places a premium on optimizing the implementation of the route computation algorithm. The scalability of CGR to very large networks remains a research topic

  19. Investigating the impact of Lake Agassiz drainage routes on the 8.2 ka cold event with a climate model

    Directory of Open Access Journals (Sweden)

    Y.-X. Li

    2009-08-01

    Full Text Available The 8.2 ka event is the most prominent abrupt climate change in the Holocene and is often believed to result from catastrophic drainage of proglacial lakes Agassiz and Ojibway (LAO that routed through the Hudson Bay and the Labrador Sea into the North Atlantic Ocean, and perturbed Atlantic meridional overturning circulation (MOC. One key assumption of this triggering mechanism is that the LAO freshwater drainage was dispersed over the Labrador Sea. Recent data, however, show no evidence of lowered δ18O values, indicative of low salinity, from the open Labrador Sea around 8.2 ka. Instead, negative δ18O anomalies are found close to the east coast of North America, extending as far south as Cape Hatteras, North Carolina, suggesting that the freshwater drainage may have been confined to a long stretch of continental shelf before fully mixing with North Atlantic Ocean water. Here we conduct a sensitivity study that examines the effects of a southerly drainage route on the 8.2 ka event with the ECBilt-CLIO-VECODE model. Hosing experiments of four routing scenarios, where freshwater was introduced to the Labrador Sea in the northerly route and to three different locations along the southerly route, were performed to investigate the routing effects on model responses. The modeling results show that a southerly drainage route is possible but generally yields reduced climatic consequences in comparison to those of a northerly route. This finding implies that more freshwater would be required for a southerly route than for a northerly route to produce the same climate anomaly. The implicated large amount of LAO drainage for a southerly routing scenario is in line with a recent geophysical modelling study of gravitational effects on sea-level change associated with the 8.2 ka event, which suggests that the volume of drainage might be larger than previously estimated.

  20. Native Freshwater Fish and Mussel Species Richness

    Data.gov (United States)

    U.S. Environmental Protection Agency — These data represent predicted current distributions of all native freshwater fish and freshwater mussels in the Middle-Atlantic region. The data are available for...

  1. Improving Reactive Ad Hoc Routing Performance by Geographic Route Length

    Institute of Scientific and Technical Information of China (English)

    CAO Yuan-da; YU Yan-bing; LU Di

    2005-01-01

    In order to help reactive ad hoc routing protocols select better-performance routes, a novel metric named geographic route length (GRL) is proposed. The relationship between GRL metric and routing performance is analyzed in detail. Combined with hop metric, GRL is applied into the original ad hoc on-demand distance vector (AODV) to demonstrate its effectiveness. Simulation experiments have shown that GRL can effectively reduce packet delay and route discovery frequency, thus can improve reactive ad hoc routing performance.

  2. A New Route Maintenance in Dynamic Source Routing Protocol

    CERN Document Server

    Shukla, Ashish

    2010-01-01

    Mobile ad-hoc network (MANET) is infrastructureless, self-organizable, multi hop packet switched network. A number of routing protocols for MANETs have been proposed in recent years. Dynamic Source Routing (DSR) protocol is one of the most popular routing protocol for ad hoc networks. This paper presents a novel method to enhance route maintenance part of DSR protocol. Our proposed route maintenance significantly increases the efficiency of the protocol at the time of route failures.

  3. Arctic freshwater export: Status, mechanisms, and prospects

    NARCIS (Netherlands)

    Haine, T.W.N.; Curry, B.; Gerdes, R.; Hansen, E.; Karcher, M.; Lee, C.; Rudels, B.; Spreen, G.; de Steur, L.; Stewart, K.D.; Woodgate, R.

    2015-01-01

    Large freshwater anomalies clearly exist in the Arctic Ocean. For example, liquid freshwater has accumulated in the Beaufort Gyre in the decade of the 2000s compared to 1980–2000, with an extra ˜ 5000 km3 — about 25% — being stored. The sources of freshwater to the Arctic from precipitation and runo

  4. Understanding individual routing behaviour.

    Science.gov (United States)

    Lima, Antonio; Stanojevic, Rade; Papagiannaki, Dina; Rodriguez, Pablo; González, Marta C

    2016-03-01

    Knowing how individuals move between places is fundamental to advance our understanding of human mobility (González et al. 2008 Nature 453, 779-782. (doi:10.1038/nature06958)), improve our urban infrastructure (Prato 2009 J. Choice Model. 2, 65-100. (doi:10.1016/S1755-5345(13)70005-8)) and drive the development of transportation systems. Current route-choice models that are used in transportation planning are based on the widely accepted assumption that people follow the minimum cost path (Wardrop 1952 Proc. Inst. Civ. Eng. 1, 325-362. (doi:10.1680/ipeds.1952.11362)), despite little empirical support. Fine-grained location traces collected by smart devices give us today an unprecedented opportunity to learn how citizens organize their travel plans into a set of routes, and how similar behaviour patterns emerge among distinct individual choices. Here we study 92 419 anonymized GPS trajectories describing the movement of personal cars over an 18-month period. We group user trips by origin-destination and we find that most drivers use a small number of routes for their routine journeys, and tend to have a preferred route for frequent trips. In contrast to the cost minimization assumption, we also find that a significant fraction of drivers' routes are not optimal. We present a spatial probability distribution that bounds the route selection space within an ellipse, having the origin and the destination as focal points, characterized by high eccentricity independent of the scale. While individual routing choices are not captured by path optimization, their spatial bounds are similar, even for trips performed by distinct individuals and at various scales. These basic discoveries can inform realistic route-choice models that are not based on optimization, having an impact on several applications, such as infrastructure planning, routing recommendation systems and new mobility solutions. PMID:26962031

  5. Dahomey Breeding Bird Survey Route

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Document contains route directions and map for the naitonal Dahomey BBS route. Includes milage for where specific listening stations are located along the route...

  6. Sleep-Route: Routing through Sleeping Sensors

    OpenAIRE

    Sarkar, Chayan; Rao, Vijay S.; Prasad, R. Venkatesha

    2014-01-01

    In this article, we propose an energy-efficient data gathering scheme for wireless sensor network called Sleep-Route, which splits the sensor nodes into two sets - active and dormant (low-power sleep). Only the active set of sensor nodes participate in data collection. The sensing values of the dormant sensor nodes are predicted with the help of an active sensor node. Virtual Sensing Framework (VSF) provides the mechanism to predict the sensing values by exploiting the data correlation among ...

  7. Nearctic freshwater tardigrades: a review

    Directory of Open Access Journals (Sweden)

    Juliana G. HINTON

    2007-09-01

    Full Text Available The distribution and ecology of limno-terrestrial Tardigrada in the Nearctic realm remain poorly known. This is especially true of freshwater tardigrades (i.e., species found in permanently submerged habitats, which have received much less attention than terrestrial species. We reviewed the literature on Nearctic freshwater tardigrades. Of 204 Nearctic limno-terrestrial tardigrade species, 44 have been collected from sediments and aquatic vegetation of streams, rivers, ponds, lakes, groundwater and cryoconite holes. Of these, 17 are hydrophilous species found exclusively or primarily in aquatic environments. Most of the remainder are probably washed in accidentally from terrestrial substrates. Among the hydrophilous species, five are endemic to the Nearctic realm and three cosmopolitan. Hypsibius dujardini is the most widely-distributed hydrophilous species. There are no regional collections of Nearctic freshwater tardigrades comparable to those for terrestrial species. Aquatic tardigrades are benthic, and are found in sediments and on aquatic vegetation. Hypsibius dujardini and other widespread species are found in both substrates, and there is thus no evidence of substrate specificity. Numerically, tardigrades usually comprise a minor component of benthic invertebrate communities. Nothing is known of their trophic relationships or dispersal in these habitats. The density of Nearctic freshwater tardigrade species peaks in the spring and/or fall. Future research should increase the spatial and temporal scale of study, and employ adequate replication.

  8. A dynamic continental runoff routing model applied to the last Northern Hemisphere deglaciation

    Directory of Open Access Journals (Sweden)

    H. Goelzer

    2012-05-01

    Full Text Available We describe and evaluate a dynamical continental runoff routing model for the Northern Hemisphere that calculates the runoff pathways in response to topographic modifications due to changes in ice thickness and isostatic adjustment. The algorithm is based on the steepest gradient method and takes as simplifying assumption that depressions are filled at all times and water drains through the lowest outlet points. It also considers changes in water storage and lake drainage in post-processing mode that become important in the presence of large ice dammed proglacial lakes. Although applicable to other scenarios as well, the model was conceived to study the routing of freshwater fluxes during the last Northern Hemisphere deglaciation. For that specific application we simulated the Northern Hemisphere ice sheets with an existing 3-D thermomechanical ice sheet model, which calculates changes in topography due to changes in ice cover and isostatic adjustment, as well as the evolution of freshwater fluxes resulting from surface ablation, iceberg calving and basal melt. The continental runoff model takes this input, calculates the drainage pathways and routes the freshwater fluxes to the surface grid points of an existing ocean model. This results in a chronology of temporally and spatially varying freshwater fluxes from the Last Glacial Maximum to the present day. We analyse the dependence of the runoff routing to grid resolution and parameters of the isostatic adjustment module of the ice sheet model.

  9. A dynamic continental runoff routing model applied to the last Northern Hemisphere deglaciation

    Directory of Open Access Journals (Sweden)

    H. Goelzer

    2011-10-01

    Full Text Available We describe and evaluate a dynamical continental runoff routing model for the Northern Hemisphere that calculates the runoff pathways in response to topographic modifications due to changes in ice thickness and isostatic adjustment. The algorithm is based on the steepest gradient method and takes as simplifying assumption that depressions are filled at all times and water drains through the lowest outlet points. It also considers changes in water storage and lake drainage that become important in the presence of large ice dammed proglacial lakes. Although applicable to other scenarios as well, the model was conceived to study the routing of freshwater fluxes during the last Northern Hemisphere deglaciation. For that specific application we simulated the Northern Hemisphere ice sheets with an existing 3-D thermomechanical ice sheet model, which calculates changes in topography due to changes in ice cover and isostatic adjustment, as well as the evolution of freshwater fluxes resulting from surface ablation, iceberg calving and basal melt. The continental runoff model takes this input, calculates the drainage pathways and routes the freshwater fluxes to the surface grid points of an existing ocean model. This results in a chronology of temporally and spatially varying freshwater fluxes from the Last Glacial Maximum to the present day. We analyse the dependence of the runoff routing to grid resolution and parameters of the isostatic adjustment module of the ice sheet model.

  10. Class network routing

    Science.gov (United States)

    Bhanot, Gyan; Blumrich, Matthias A.; Chen, Dong; Coteus, Paul W.; Gara, Alan G.; Giampapa, Mark E.; Heidelberger, Philip; Steinmacher-Burow, Burkhard D.; Takken, Todd E.; Vranas, Pavlos M.

    2009-09-08

    Class network routing is implemented in a network such as a computer network comprising a plurality of parallel compute processors at nodes thereof. Class network routing allows a compute processor to broadcast a message to a range (one or more) of other compute processors in the computer network, such as processors in a column or a row. Normally this type of operation requires a separate message to be sent to each processor. With class network routing pursuant to the invention, a single message is sufficient, which generally reduces the total number of messages in the network as well as the latency to do a broadcast. Class network routing is also applied to dense matrix inversion algorithms on distributed memory parallel supercomputers with hardware class function (multicast) capability. This is achieved by exploiting the fact that the communication patterns of dense matrix inversion can be served by hardware class functions, which results in faster execution times.

  11. Routed planar networks

    Directory of Open Access Journals (Sweden)

    David J. Aldous

    2016-04-01

    Full Text Available Modeling a road network as a planar graph seems very natural. However, in studying continuum limits of such networks it is useful to take {\\em routes} rather than {\\em edges} as primitives. This article is intended to introduce the relevant (discrete setting notion of {\\em routed network} to graph theorists. We give a naive classification of all 71 topologically different such networks on 4 leaves, and pose a variety of challenging research questions.

  12. Routing Service Quality—Local Driver Behavior Versus Routing Services

    DEFF Research Database (Denmark)

    Ceikute, Vaida; Jensen, Christian S.

    2013-01-01

    of the quality of one kind of location-based service, namely routing services. Specifically, the paper presents a framework that enables the comparison of the routes provided by routing services with the actual driving behaviors of local drivers. Comparisons include route length, travel time, and also route...... experiments with real vehicle trajectory data and an existing online navigation service. It is found that the availability of information about previous trips enables better prediction of route travel time and makes it possible to provide the users with more popular routes than does a conventional navigation...

  13. Modeling Routing Overhead Generated by Wireless Proactive Routing Protocols

    CERN Document Server

    Javaid, Nadeem; Javaid, Akmal; Malik, Shahzad A

    2011-01-01

    In this paper, we present a detailed framework consisting of modeling of routing overhead generated by three widely used proactive routing protocols; Destination-Sequenced Distance Vector (DSDV), Fish-eye State Routing (FSR) and Optimized Link State Routing (OLSR). The questions like, how these protocols differ from each other on the basis of implementing different routing strategies, how neighbor estimation errors affect broadcast of route requests, how reduction of broadcast overhead achieves bandwidth, how to cope with the problem of mobility and density, etc, are attempted to respond. In all of the above mentioned situations, routing overhead and delay generated by the chosen protocols can exactly be calculated from our modeled equations. Finally, we analyze the performance of selected routing protocols using our proposed framework in NS-2 by considering different performance parameters; Route REQuest (RREQ) packet generation, End-to-End Delay (E2ED) and Normalized Routing Load (NRL) with respect to varyi...

  14. Modeling Routing Overhead Generated by Wireless Reactive Routing Protocols

    CERN Document Server

    Javaid, Nadeem; Javaid, Akmal; Malik, Shahzad A

    2011-01-01

    In this paper, we have modeled the routing over- head generated by three reactive routing protocols; Ad-hoc On-demand Distance Vector (AODV), Dynamic Source Routing (DSR) and DYnamic MANET On-deman (DYMO). Routing performed by reactive protocols consists of two phases; route discovery and route maintenance. Total cost paid by a protocol for efficient routing is sum of the cost paid in the form of energy consumed and time spent. These protocols majorly focus on the optimization performed by expanding ring search algorithm to control the flooding generated by the mechanism of blind flooding. So, we have modeled the energy consumed and time spent per packet both for route discovery and route maintenance. The proposed framework is evaluated in NS-2 to compare performance of the chosen routing protocols.

  15. Cable Bacteria in Freshwater Sediments

    DEFF Research Database (Denmark)

    Risgaard-Petersen, Nils; Kristiansen, Michael; Frederiksen, Rasmus;

    2015-01-01

    In marine sediments cathodic oxygen reduction at the sediment surface can be coupled to anodic sulfide oxidation in deeper anoxic layers through electrical currents mediated by filamentous, multicellular bacteria of the Desulfobulbaceae family, the so-called cable bacteria. Until now, cable...... bacteria have only been reported from marine environments. In this study, we demonstrate that cable bacteria also occur in freshwater sediments. In a first step, homogenized sediment collected from the freshwater stream Giber Å, Denmark, was incubated in the laboratory. After 2 weeks, pH signatures...... marine cable bacteria, with the genus Desulfobulbus as the closest cultured lineage. The results of the present study indicate that electric currents mediated by cable bacteria could be important for the biogeochemistry in many more environments than anticipated thus far and suggest a common evolutionary...

  16. Study on polychlorobiphenyl serum levels in French consumers of freshwater fish

    Energy Technology Data Exchange (ETDEWEB)

    Desvignes, Virginie, E-mail: virginie.desvignes@anses.fr [Risk Assessment Department, French Agency for Food, Environmental and Occupational Health and Safety (ANSES), 27–31, avenue du Général Leclerc, Maisons-Alfort, F-94701 (France); Volatier, Jean-Luc [Risk Assessment Department, French Agency for Food, Environmental and Occupational Health and Safety (ANSES), 27–31, avenue du Général Leclerc, Maisons-Alfort, F-94701 (France); Bels, Frédéric de [Division for Public Health and Care, French National Cancer Institute (INCa), 52, avenue André Morizet, Boulogne Billancourt Cedex, F-92513 (France); Zeghnoun, Abdelkrim [Department of Environmental Health, French Institute for Public Health Surveillance (InVS), 12, rue du Val d' Osne, Saint-Maurice, F-94415 (France); Favrot, Marie-Christine [Ministry of Health, 14, avenue Duquesne, Paris, F-75350 (France); Marchand, Philippe; Le Bizec, Bruno [LUNAM Université, Oniris, Laboratoire d' Etude des Résidus et Contaminants dans les Aliments (LABERCA), USC INRA 1329, Nantes, F-44307 (France); Rivière, Gilles; Leblanc, Jean-Charles; Merlo, Mathilde [Risk Assessment Department, French Agency for Food, Environmental and Occupational Health and Safety (ANSES), 27–31, avenue du Général Leclerc, Maisons-Alfort, F-94701 (France)

    2015-02-01

    Introduction: Polychlorobiphenyls (PCBs) are persistent pollutants that are widespread in the environment and in foodstuffs, particularly in freshwater fish, which frequently exceed the maximum levels set by European regulations. Objectives: First, we describe the consumption of freshwater fish and serum PCB levels in French anglers, a population expected to have the highest level of dietary PCB exposure. Second, we investigated whether there is a statistical relationship between serum PCB levels and the angler consumption of freshwater fish with high PCB bioaccumulation potential (PCB-BP{sup +} freshwater fish) in order to make recommendations with regard to safe consumption of freshwater fish. Methods: We conducted a survey of anglers from six sites with contrasting PCB contamination levels. The survey included a food consumption frequency questionnaire and blood samples were taken to assess serum PCB levels. We used a regression model to determine the main factors contributing to serum PCB levels. Results: Consumption of PCB-BP{sup +} freshwater fish was relatively infrequent. Serum PCB levels of the study population and of women of childbearing age were in the same range as those observed in the French population and in neighbouring European countries, but higher than in the North American population. The two factors with the highest positive association with serum PCB levels were age (R{sup 2} = 61%) and the consumption of PCB-BP{sup +} freshwater fish (R{sup 2} = 2%). Using the regression model, we calculated, for several scenarios depending on the age and gender of the population, the maximum annual frequencies for PCB-BP{sup +} freshwater fish consumption that do not exceed the critical body burden threshold. Conclusion: Following the results of this study, the French agency for food, environmental and occupational health and safety (ANSES) issued an opinion and recommended some specific maximum freshwater fish consumption frequencies to protect the French

  17. Study on polychlorobiphenyl serum levels in French consumers of freshwater fish

    International Nuclear Information System (INIS)

    Introduction: Polychlorobiphenyls (PCBs) are persistent pollutants that are widespread in the environment and in foodstuffs, particularly in freshwater fish, which frequently exceed the maximum levels set by European regulations. Objectives: First, we describe the consumption of freshwater fish and serum PCB levels in French anglers, a population expected to have the highest level of dietary PCB exposure. Second, we investigated whether there is a statistical relationship between serum PCB levels and the angler consumption of freshwater fish with high PCB bioaccumulation potential (PCB-BP+ freshwater fish) in order to make recommendations with regard to safe consumption of freshwater fish. Methods: We conducted a survey of anglers from six sites with contrasting PCB contamination levels. The survey included a food consumption frequency questionnaire and blood samples were taken to assess serum PCB levels. We used a regression model to determine the main factors contributing to serum PCB levels. Results: Consumption of PCB-BP+ freshwater fish was relatively infrequent. Serum PCB levels of the study population and of women of childbearing age were in the same range as those observed in the French population and in neighbouring European countries, but higher than in the North American population. The two factors with the highest positive association with serum PCB levels were age (R2 = 61%) and the consumption of PCB-BP+ freshwater fish (R2 = 2%). Using the regression model, we calculated, for several scenarios depending on the age and gender of the population, the maximum annual frequencies for PCB-BP+ freshwater fish consumption that do not exceed the critical body burden threshold. Conclusion: Following the results of this study, the French agency for food, environmental and occupational health and safety (ANSES) issued an opinion and recommended some specific maximum freshwater fish consumption frequencies to protect the French general population. - Highlights:

  18. Contribution of glacier runoff to freshwater discharge into the Gulf of Alaska

    Science.gov (United States)

    Neal, E.G.; Hood, E.; Smikrud, K.

    2010-01-01

    Watersheds along the Gulf of Alaska (GOA) are undergoing climate warming, glacier volume loss, and shifts in the timing and volume of freshwater delivered to the eastern North Pacific Ocean. We estimate recent mean annual freshwater discharge to the GOA at 870 km3 yr-1. Small distributed coastal drainages contribute 78% of the freshwater discharge with the remainder delivered by larger rivers penetrating coastal ranges. Discharge from glaciers and icefields accounts for 47% of total freshwater discharge, with 10% coming from glacier volume loss associated with rapid thinning and retreat of glaciers along the GOA. Our results indicate the region of the GOA from Prince William Sound to the east, where glacier runoff contributes 371 km3 yr -1, is vulnerable to future changes in freshwater discharge as a result of glacier thinning and recession. Changes in timing and magnitude of freshwater delivery to the GOA could impact coastal circulation as well as biogeochemical fluxes to near-shore marine ecosystems and the eastern North Pacific Ocean. Copyright ?? 2010 by the American Geophysical Union.

  19. Magnetic resonance imaging of live freshwater mussels (Unionidae)

    Science.gov (United States)

    Michael, Holliman F.; Davis, D.; Bogan, A.E.; Kwak, T.J.; Gregory, Cope W.; Levine, J.F.

    2008-01-01

    We examined the soft tissues of live freshwater mussels, Eastern elliptio Elliptio complanata, via magnetic resonance imaging (MRI), acquiring data with a widely available human whole-body MRI system. Anatomical features depicted in the profile images included the foot, stomach, intestine, anterior and posterior adductor muscles, and pericardial cavity. Noteworthy observations on soft tissue morphology included a concentration of lipids at the most posterior aspect of the foot, the presence of hemolymph-filled fissures in the posterior adductor muscle, the presence of a relatively large hemolymph-filled sinus adjacent to the posterior adductor muscle (at the ventral-anterior aspect), and segmentation of the intestine (a diagnostic description not reported previously in Unionidae). Relatively little is known about the basic biology and ecological physiology of freshwater mussels. Traditional approaches for studying anatomy and tissue processes, and for measuring sub-lethal physiological stress, are destructive or invasive. Our study, the first to evaluate freshwater mussel soft tissues by MRI, clarifies the body plan of unionid mussels and demonstrates the efficacy of this technology for in vivo evaluation of the structure, function, and integrity of mussel soft tissues. ?? 2008, The American Microscopical Society, Inc.

  20. Cross-cutting Perspective Freshwater

    OpenAIRE

    Furusho, C.; Vidaurre, R.; La Jeunesse, I.; M. H. Ramos

    2016-01-01

    One singularity of northwestern Europe (NWE) is that severe droughts are rare events in the region and water scarcity has hardly been experienced in its history. The DROP pilot sites are not exceptions to this context. Although the lack of a drought history in wet areas can explain why drought and water scarcity are not necessarily the focus of (if ever considered in) river basin management plans, it must be noted that freshwater availability for drinking water provision remains a priority st...

  1. Sulfur cycling in freshwater sediments

    Science.gov (United States)

    Klug, M. J.

    1985-01-01

    Organic sulfur containing compounds represent greater than 80% of the total sulfur in sediments of eutrophic freshwater lakes. Although sedimentary sulfur is predominantly in the form of organic compounds, more sulfur is transformed by sulfate reduction than by any other process. Rates of sulfate reduction in these sediments average 7 mmol/sq m/day. This rate is 19 times greater than the net rate of production of inorganic sulfur from organic compounds on an annual basis.

  2. Multihop Wireless Networks Opportunistic Routing

    CERN Document Server

    Zeng, Kai; Li, Ming

    2011-01-01

    This book provides an introduction to opportunistic routing an emerging technology designed to improve the packet forwarding reliability, network capacity and energy efficiency of multihop wireless networks This book presents a comprehensive background to the technological challenges lying behind opportunistic routing. The authors cover many fundamental research issues for this new concept, including the basic principles, performance limit and performance improvement of opportunistic routing compared to traditional routing, energy efficiency and distributed opportunistic routing protocol desig

  3. Collective network routing

    Science.gov (United States)

    Hoenicke, Dirk

    2014-12-02

    Disclosed are a unified method and apparatus to classify, route, and process injected data packets into a network so as to belong to a plurality of logical networks, each implementing a specific flow of data on top of a common physical network. The method allows to locally identify collectives of packets for local processing, such as the computation of the sum, difference, maximum, minimum, or other logical operations among the identified packet collective. Packets are injected together with a class-attribute and an opcode attribute. Network routers, employing the described method, use the packet attributes to look-up the class-specific route information from a local route table, which contains the local incoming and outgoing directions as part of the specifically implemented global data flow of the particular virtual network.

  4. Roots and routes

    DEFF Research Database (Denmark)

    Christensen, Ann-Dorte; Jensen, Sune Qvotrup

    2011-01-01

    arguing that there is a dynamic interplay between roots and routes in people's lives. The empirical point of departure is narratives about roots and routes by ethnic minorities settled in Aalborg East, an underprivileged neighbourhood in northern Denmark. One of the main findings is a gap between the...... somewhat paradoxical finding is that it appears to be more difficult for transnational migrants to maintain their roots in the country of origin when they go back than it was to establish new roots in the host country...

  5. The freshwater reservoir effect in radiocarbon dating

    DEFF Research Database (Denmark)

    Philippsen, Bente

    2013-01-01

    of magnitude and degree of variability of the freshwater reservoir effect over short and long timescales. Radiocarbon dating of recent water samples, aquatic plants, and animals, shows that age differences of up to 2000 14C years can occur within one river. The freshwater reservoir effect has also implications...... for radiocarbon dating of Mesolithic pottery from inland sites of the Ertebølle culture in Northern Germany. The surprisingly old ages of the earliest pottery most probably are caused by a freshwater reservoir effect. In a sediment core from the Limfjord, northern Denmark, the impact of the freshwater reservoir...... effect on radiocarbon dating in an estuarine environment is examined. Here, freshwater influence causes reservoir ages to vary between 250 and 700 14C years during the period 5400 BC - AD 700. The examples in this study show clearly that the freshwater reservoir effect can seriously corrupt radiocarbon...

  6. Pre-anthropocene mercury residues in North American freshwater fish.

    Science.gov (United States)

    Hope, Bruce K; Louch, Jeff

    2014-04-01

    Mercury (Hg) has been entering the environment from both natural and anthropogenic sources for millennia, and humans have been influencing its environmental transport and fate from well before the Industrial Revolution. Exposure to Hg (as neurotoxic monomethylmercury [MeHg]) occurs primarily through consumption of finfish, shellfish, and marine mammals, and regulatory limits for MeHg concentrations in fish tissue have steadily decreased as information on its health impacts has become available. These facts prompted us to consider 2 questions: 1) What might the MeHg levels in fish tissue have been in the pre-Anthropocene, before significant human impacts on the environment? and 2) How would these pre-Anthropocene levels have compared with current regulatory criteria for MeHg residues in fish tissue? We addressed the first question by estimating pre-Anthropocene concentrations of MeHg in the tissues of prey and predatory fish with an integrated Hg speciation, transport, fate, and food web model (SERAFM), using estimated Hg concentrations in soil, sediment, and atmospheric deposition before the onset of significant human activity (i.e., ≤2000 BCE). Model results show MeHg residues in fish varying depending on the characteristics of the modeled water body, which suggests that Hg in fish tissue is best considered at the scale of individual watersheds or water bodies. We addressed the second question by comparing these model estimates with current regulatory criteria and found that MeHg residues in predatory (but not prey) fish could have approached or exceeded these criteria in some water bodies during the pre-Anthropocene. This suggests that the possibility of naturally occurring levels of Hg in fish below which it is not possible to descend, regardless of where those levels stand with respect to current regulatory limits. Risk management decisions made under these circumstances have the potential to be ineffectual, frustrating, and costly for decision makers and stakeholders alike, suggesting the need for regulatory flexibility when addressing the issue of Hg in fish. PMID:24458807

  7. South American freshwater needlefishes (Belonidae) of the genus Pseudotylosurus

    NARCIS (Netherlands)

    Collete, B.B.

    1974-01-01

    Pseudotylosurus Fernández Yépez is considered a valid genus of Belonidae based on the following combination of characters: depressed caudal peduncle; long narrow side branches to lateral line; pleural ribs attached to fourth vertebra; nasal papilla spatulate; lower pharyngeal plate and upper pharyng

  8. Whirlpool routing for mobility

    KAUST Repository

    Lee, Jung Woo

    2010-01-01

    We present the Whirlpool Routing Protocol (WARP), which efficiently routes data to a node moving within a static mesh. The key insight in WARP\\'s design is that data traffic can use an existing routing gradient to efficiently probe the topology, repair the routing gradient, and communicate these repairs to nearby nodes. Using simulation, controlled testbeds, and real mobility experiments, we find that using the data plane for topology maintenance is highly effective due to the incremental nature of mobility updates. WARP leverages the fact that converging flows at a destination make the destination have the region of highest traffic. We provide a theoretical basis for WARP\\'s behavior, defining an "update area" in which the topology must adjust when a destination moves. As long as packets arrive at a destination before it moves outside of the update area, WARP can repair the topology using the data plane. Compared to existing protocols, such as DYMO and HYPER, WARP\\'s packet drop rate is up to 90% lower while sending up to 90% fewer packets.

  9. SET-Routes programme

    CERN Multimedia

    Marietta Schupp, EMBL Photolab

    2008-01-01

    Dr Sabine Hentze, specialist in human genetics, giving an Insight Lecture entitled "Human Genetics – Diagnostics, Indications and Ethical Issues" on 23 September 2008 at EMBL Heidelberg. Activities in a achool in Budapest during a visit of Angela Bekesi, Ambassadors for the SET-Routes programme.

  10. SET-Routes programme

    CERN Document Server

    CERN audiovisual service

    2009-01-01

    The SET-Routes programme, launched in 2007 with the goal of attracting girls and young women to careers in science, came to an end in April this year. The result of a collaboration between EMBL, EMBO and CERN, the programme established a network of "ambassadors", women scientists who went out to talk about their careers in science at schools and universities across Europe.

  11. An evaluation of freshwater mussel toxicity data in the derivation of water quality guidance and standards for copper

    Science.gov (United States)

    March, F.A.; Dwyer, F.J.; Augspurger, T.; Ingersoll, C.G.; Wang, N.; Mebane, C.A.

    2007-01-01

    The state of Oklahoma has designated several areas as freshwater mussel sanctuaries in an attempt to provide freshwater mussel species a degree of protection and to facilitate their reproduction. We evaluated the protection afforded freshwater mussels by the U.S. Environmental Protection Agency (U.S. EPA) hardness-based 1996 ambient copper water quality criteria, the 2007 U.S. EPA water quality criteria based on the biotic ligand model and the 2005 state of Oklahoma copper water quality standards. Both the criterion maximum concentration and criterion continuous concentration were evaluated. Published acute and chronic copper toxicity data that met American Society for Testing and Materials guidance for test acceptability were obtained for exposures conducted with glochidia or juvenile freshwater mussels. We tabulated toxicity data for glochidia and juveniles to calculate 20 species mean acute values for freshwater mussels. Generally, freshwater mussel species mean acute values were similar to those of the more sensitive species included in the U.S. EPA water quality derivation database. When added to the database of genus mean acute values used in deriving 1996 copper water quality criteria, 14 freshwater mussel genus mean acute values included 10 of the lowest 15 genus mean acute values, with three mussel species having the lowest values. Chronic exposure and sublethal effects freshwater mussel data available for four species and acute to chronic ratios were used to evaluate the criterion continuous concentration. On the basis of the freshwater mussel toxicity data used in this assessment, the hardness-based 1996 U.S. EPA water quality criteria, the 2005 Oklahoma water quality standards, and the 2007 U.S. EPA water quality criteria based on the biotic ligand model might need to be revised to afford protection to freshwater mussels. ?? 2007 SETAC.

  12. Freshwater Variability in the Arctic Ocean and Subpolar North Atlantic: a Comparison from the 1990s to Present

    Science.gov (United States)

    Horn, Myriel; Rabe, Benjamin; Schauer, Ursula

    2016-04-01

    A significant increase in liquid freshwater content has been observed in the Arctic Ocean over the last 20 years, whereas the Arctic sea ice volume shrank significantly. In contrast, the North Atlantic became more saline in recent years. Both regions are of great importance for the global ocean circulation and climate, and salinity changes may have a profound impact on the global climate. We found that for the period between 1992 and 2013, the liquid freshwater content of the subpolar North Atlantic, calculated from objectively mapped in-situ salinity measurements, and the total freshwater content of the Arctic Ocean, i.e. the liquid freshwater content and freshwater stored in sea ice, are significantly negative correlated (r=-0.77). Moreover, the amount of the anomalies are of the same size. Furthermore, the time series hint at multi-decadal oscillations. The highest negative correlation with the total freshwater content of the Arctic Ocean can be found in the Irminger and Labrador Seas, while we observed a positive correlation east of the Mid-Atlantic Ridge at the path of the North Atlantic Current, which is the source of Atlantic Water entering the Arctic Ocean through the Nordic Seas. We suggest a redistribution of freshwater as a response to frequent changes in atmospheric pressure patterns. Under certain conditions the freshwater is re-routed and kept in the Arctic Ocean, while it is released under other conditions. We conclude that decadal scale changes of the freshwater content in the North Atlantic, particularly those in the deep water formation sites like the Labrador Sea, are originating in the Arctic Ocean.

  13. Davis Pond Freshwater Prediversion Biomonitoring Study: Freshwater Fisheries and Eagles

    Science.gov (United States)

    Jenkins, Jill A.; Bourgeois, E. Beth; Jeske, Clint W.

    2008-01-01

    In January 2001, the construction of the Davis Pond freshwater diversion structure was completed by the U.S. Army Corps of Engineers. The diversion of freshwater from the Mississippi River is intended to mitigate saltwater intrusion from the Gulf of Mexico and to lessen the concomitant loss of wetland areas. In addition to the freshwater inflow, Barataria Bay basin would receive nutrients, increased flows of sediments, and water-borne and sediment-bound compounds. The purpose of this biomonitoring study was, therefore, to serve as a baseline for prediversion concentrations of selected contaminants in bald eagle (Haliaeetus leucocephalus) nestlings (hereafter referred to as eaglets), representative freshwater fish, and bivalves. Samples were collected from January through June 2001. Two similarly designed postdiversion studies, as described in the biological monitoring program, are planned. Active bald eagle nests targeted for sampling eaglet blood (n = 6) were generally located southwest and south of the diversion structure. The designated sites for aquatic animal sampling were at Lake Salvador, at Lake Cataouatche, at Bayou Couba, and along the Mississippi River. Aquatic animals representative of eagle prey were collected. Fish were from three different trophic levels and have varying feeding strategies and life histories. These included herbivorous striped mullet (Mugil cephalus), omnivorous blue catfish (Ictalurus furcatus), and carnivorous largemouth bass (Micropterus salmoides). Three individuals per species were collected at each of the four sampling sites. Freshwater Atlantic rangia clams (Rangia cuneata) were collected at the downstream marsh sites, and zebra mussels (Dreissena spp.) were collected on the Mississippi River. The U.S. Geological Survey (USGS) Biomonitoring of Environmental Status and Trends (BEST) protocols served as guides for fish sampling and health assessments. Fish are useful for monitoring aquatic ecosystems because they accumulate

  14. American Religion

    Institute of Scientific and Technical Information of China (English)

    田甜

    2008-01-01

    It is said that American religion,as a great part of American culture,plays an important role in American culture. It is hoped that some ideas can be obtained from this research paper,which focuses on analyzing the great impact is produced to American culture by American religion. Finally, this essay gives two useful standpoints to English learners:Understunding American religion will help understand the American history, culture and American people,and help you to communic.ate with them better. Understanding American religion will help you understand English better.

  15. Route Repetition and Route Retracing: Effects of Cognitive Aging

    Directory of Open Access Journals (Sweden)

    Jan Malte Wiener

    2012-05-01

    Full Text Available Retracing a recently traveled route is a frequent navigation task when learning novel routes or exploring unfamiliar environments. In the present study we utilized virtual environments technology to investigate age-related differences in repeating and retracing a learned route. In the training phase of the experiment participants were guided along a route consisting of multiple intersections each featuring one unique landmark. In the subsequent test phase, they were guided along short sections of the route and asked to indicate overall travel direction (repetition or retracing, the direction required to continue along the route, and the next landmark they would encounter. Results demonstrate age-related deficits in all three tasks. More specifically, in contrast to younger participants, the older participants had greater problems during route retracing than during route repetition. While route repetition can be solved with egocentric response or route strategies, successfully retracing a route requires allocentric processing. The age-related deficits in route retracing are discussed in the context of impaired allocentric processing and shifts from allocentric to egocentric navigation strategies as a consequence of age-related hippocampal degeneration.

  16. Freshwater autotrophic picoplankton: a review

    Directory of Open Access Journals (Sweden)

    John G. STOCKNER

    2002-02-01

    Full Text Available Autotrophic picoplankton (APP are distributed worldwide and are ubiquitous in all types of lakes of varying trophic state. APP are major players in carbon production in all aquatic ecosystems, including extreme environments such as cold ice-covered and/or warm tropical lakes and thermal springs. They often form the base of complex microbial food webs, becoming prey for a multitude of protozoan and micro-invertebrate grazers, that effectively channel APP carbon to higher trophic levels including fish. In this review we examine the existing literature on freshwater autotrophic picoplankton, setting recent findings and current ecological issues within an historic framework, and include a description of the occurrence and distribution of both single-cell and colonial APP (picocyanobacteria in different types of lakes. In this review we place considerable emphasis on methodology and ecology, including sampling, counting, preservation, molecular techniques, measurement of photosynthesis, and include extensive comment on their important role in microbial food webs. The model outlined by Stockner of an increase of APP abundance and biomass and a decrease of its relative importance with the increase of phosphorus concentration in lakes has been widely accepted, and only recently confirmed in marine and freshwater ecosystems. Nevertheless the relationship which drives the APP presence and importance in lakes of differing trophic status appears with considerable variation so we must conclude that the success of APP in oligotrophic lakes worldwide is not a certainty but highly probable.

  17. Issues of Routing in VANET

    OpenAIRE

    Raja, Umar Waqas; Mustafa, Bilal

    2010-01-01

    Vehicular Ad Hoc Network (VANET) is a sub class of mobile ad hoc networks. VANET provides wireless communication among vehicles and vehicle to road side equipments. The communication between vehicles is used for safety, comfort and for entertainment as well. The performance of communication depends on how better the routing takes place in the network. Routing of data depends on the routing protocols being used in network. In this study we investigated about different ad hoc routing protocols ...

  18. Tidal Freshwater Wetlands: Variation and Changes

    NARCIS (Netherlands)

    Barendregt, A.; Swarth, C.W.

    2013-01-01

    Tidal freshwater wetlands (TFW) are situated in the upper estuary in a zone bordered upstream by the nontidal river and downstream by the oligohaline region. Here, discharge of freshwater from the river and the daily tidal pulse from the sea combine to create conditions where TFW develop. TFW are of

  19. Effects of Pollution on Freshwater Fish.

    Science.gov (United States)

    Brungs, W. A.; And Others

    1978-01-01

    Presents a literature review of the effects of pollution on freshwater fish, covering publications of 1976-77. This review includes: (1) water quality; (2) pesticide pollutants; (3) chemical pollutants; (4) miscellaneous pollutants; and (5) physical factors of pollution on freshwater fish. A list of 338 references is also presented. (HM)

  20. Farming of Freshwater Rainbow Trout in Denmark

    DEFF Research Database (Denmark)

    Jokumsen, Alfred; Svendsen, Lars Moeslund

    Textbook on Farming of Freshwater Rainbow Trout in Denmark. Danish edition with the title: Opdræt af regnbueørred i Danmark......Textbook on Farming of Freshwater Rainbow Trout in Denmark. Danish edition with the title: Opdræt af regnbueørred i Danmark...

  1. Freshwater Ecology. LC Science Tracer Bullet.

    Science.gov (United States)

    Niskern, Diana, Comp.

    Freshwater ecosystems include lakes, ponds, streams, rivers, and certain types of wetlands. This literature and resources guide is not intended to be a comprehensive bibliography on freshwater ecology; the guide is designed--as the name of the series implies--to put the reader or student "on target." Other literature guides related to freshwater…

  2. Alternative iron making routes

    Energy Technology Data Exchange (ETDEWEB)

    Kaushik, P.; Sharma, T. [Indian School of Mines, Dhanbad (India)

    2002-07-01

    The versatile route of iron production 'blast furnace' technique is being replaced by widely accepted Corex technology, Midrex process using Fastmelt ironmaking, eco-friendly Romelt process, more innovative Ausmelt & Hismelt technology, TATA KORF Mini blast furnace improvement, 'quickest iron through Orbiting Plasma', Direct iron ore smelting process, Conred, AISI-Hyl, Inred processes, Direct iron ore reduction methods, their comparison and proposed modifications. 18 refs., 11 figs., 14 tabs.

  3. Electronic route information panels (DRIPs).

    NARCIS (Netherlands)

    2008-01-01

    Also in the Netherlands, the term Dynamic Route Information Panel (DRIP) is used for an electronic route information panel. A DRIP usually indicates whether there are queues on the various routes to a particular destination and how long they are. On certain locations DRIPS also give the estimated tr

  4. Effective local dynamic routing strategy for air route networks

    Institute of Scientific and Technical Information of China (English)

    Wu Wenjun; Zhao Lingxi

    2015-01-01

    With the rapid development of air transportation, network service ability has attracted a lot of attention in academe. Aiming to improve the throughput of the air route network (ARN), we propose an effective local dynamic routing strategy in this paper. Several factors, such as the rout-ing distance, the geographical distance and the real-time local traffic, are taken into consideration. When the ARN is in the normal free-flow state, the proposed strategy can recover the shortest path routing (SPR) strategy. When the ARN undergoes congestion, the proposed strategy changes the paths of flights based on the real-time local traffic information. The throughput of the Chinese air route network (CARN) is evaluated. Results confirm that the proposed strategy can significantly improve the throughput of CARN. Meanwhile, the increase in the average flying distance and time is tiny. Results also indicate the importance of the distance related factors in a routing strategy designed for the ARN.

  5. Robustness of airline route networks

    Science.gov (United States)

    Lordan, Oriol; Sallan, Jose M.; Escorihuela, Nuria; Gonzalez-Prieto, David

    2016-03-01

    Airlines shape their route network by defining their routes through supply and demand considerations, paying little attention to network performance indicators, such as network robustness. However, the collapse of an airline network can produce high financial costs for the airline and all its geographical area of influence. The aim of this study is to analyze the topology and robustness of the network route of airlines following Low Cost Carriers (LCCs) and Full Service Carriers (FSCs) business models. Results show that FSC hubs are more central than LCC bases in their route network. As a result, LCC route networks are more robust than FSC networks.

  6. Personal continuous route pattern mining

    Institute of Scientific and Technical Information of China (English)

    Qian YE; Ling CHEN; Gen-cai CHEN

    2009-01-01

    In the daily life, people often repeat regular routes in certain periods. In this paper, a mining system is developed to find the continuous route patterns of personal past trips. In order to count the diversity of personal moving status, the mining system employs the adaptive GPS data recording and five data filters to guarantee the clean trips data. The mining system uses a client/server architecture to protect personal privacy and to reduce the computational load. The server conducts the main mining procedure but with insufficient information to recover real personal routes. In order to improve the scalability of sequential pattern mining, a novel pattern mining algorithm, continuous route pattern mining (CRPM), is proposed. This algorithm can tolerate the different disturbances in real routes and extract the frequent patterns. Experimental results based on nine persons' trips show that CRPM can extract more than two times longer route patterns than the traditional route pattern mining algorithms.

  7. Pathogenic agents in freshwater resources

    Science.gov (United States)

    Geldreich, Edwin E.

    1996-02-01

    Numerous pathogenic agents have been found in freshwaters used as sources for water supplies, recreational bathing and irrigation. These agents include bacterial pathogens, enteric viruses, several protozoans and parasitic worms more common to tropical waters. Although infected humans are a major source of pathogens, farm animals (cattle, sheep, pigs), animal pets (dogs, cats) and wildlife serve as significant reservoirs and should not be ignored. The range of infected individuals within a given warm-blooded animal group (humans included) may range from 1 to 25%. Survival times for pathogens in the water environment may range from a few days to as much as a year (Ascaris, Taenia eggs), with infective dose levels varying from one viable cell for several primary pathogenic agents to many thousands of cells for a given opportunistic pathogen.As pathogen detection in water is complex and not readily incorporated into routine monitoring, a surrogate is necessary. In general, indicators of faecal contamination provide a positive correlation with intestinal pathogen occurrences only when appropriate sample volumes are examined by sensitive methodology.Pathways by which pathogens reach susceptible water users include ingestion of contaminated water, body contact with polluted recreational waters and consumption of salad crops irrigated by polluted freshwaters. Major contributors to the spread of various water-borne pathogens are sewage, polluted surface waters and stormwater runoff. All of these contributions are intensified during periods of major floods. Several water-borne case histories are cited as examples of breakdowns in public health protection related to water supply, recreational waters and the consumption of contaminated salad crops. In the long term, water resource management must focus on pollution prevention from point sources of waste discharges and the spread of pathogens in watershed stormwater runoff.

  8. Linear Network Fractional Routing

    Directory of Open Access Journals (Sweden)

    S.ASOKAN,

    2011-07-01

    Full Text Available A Network is a finite directed acyclic graph with source messages from a fixed alphabet and message demands at sink nodes. Linear Programming is an algorithm design method. It can be used whenthe solution to a problem can be viewed as the result of a sequence of decisions. The Linear Programming model for the network problem where in every variable has a value one or zero. The problem is todetermine a method of transmitting the messages through the network such that all sink demands are satisfied. We will prove fractional routing capacity for some solvable network using Linear Programmingmodel.

  9. Formulation of an Integrated Model for Freshwater Resources Policy Evaluation in Jordan

    Science.gov (United States)

    Gorelick, S.; Yoon, J.; Gawel, E.; Klauer, B.; Klassert, C. J. A.; Sigel, K.; Tilmant, A.; Lachaut, T.; Avisse, N.; Harou, J. J.; Padula, S.; Mustafa, D.

    2014-12-01

    Jordan is one of the four water poorest countries in the world. It is a highly vulnerable arid region whose freshwater system is at a tipping point due to the confluence of severely limited water supplies, rapid population growth, refugee influxes, climate change and variability, internal and transboundary competition for shared freshwater resources, and institutional impediments. Our team is engaged in an interdisciplinary effort aimed at developing a new approach to evaluate policies that enhance sustainability of freshwater resource systems. Our work adopts a multi-agent modeling framework that incorporates institutional complexity to evaluate policy instruments for improving water security in Jordan. We are developing this model using a modular approach, integrating biophysical modules that simulate natural and engineered phenomena (e.g., groundwater-surface water flow, reservoir storage, network routing, salt balance, and crop yield) with human modules that represent behavior at multiple scales of decision making. The human modules adopt a multi-agent simulation approach, defining agents as autonomous decision-makers at the government, administrative, organizational, and user levels. Our goal is to construct a suite of policy intervention scenarios that will form the basis for analysis of freshwater sustainability. This work has benefitted from a strong working relationship with leaders of the water sector in Jordan. Our approach and the merit of the policy interventions should have significant transfer value to other water-stressed regions.

  10. The freshwater reservoir effect in radiocarbon dating

    DEFF Research Database (Denmark)

    Philippsen, Bente

    case studies will show the degree of variability of the freshwater reservoir effect over short and long timescales. Radiocarbon dating of recent water samples, aquatic plants and animals, shows that age differences of up to 2000 years can occur within one river. In the Limfjord, freshwater influence...... caused reservoir ages to vary between 250 and 700 years during the period 5400 BC - AD 700. Finally, I will discuss the implications of the freshwater reservoir effect for radiocarbon dating of Mesolithic pottery from inland sites of the Ertebølle culture in Northern Germany....

  11. 40 CFR 35.1605-3 - Publicly owned freshwater lake.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Publicly owned freshwater lake. 35.1605... Owned Freshwater Lakes § 35.1605-3 Publicly owned freshwater lake. A freshwater lake that offers public access to the lake through publicly owned contiguous land so that any person has the same opportunity...

  12. Freshwater outburst from Lake Superior as a trigger for the cold event 9300 years ago.

    Science.gov (United States)

    Yu, Shi-Yong; Colman, Steven M; Lowell, Thomas V; Milne, Glenn A; Fisher, Timothy G; Breckenridge, Andy; Boyd, Matthew; Teller, James T

    2010-06-01

    Paleoclimate proxy records reveal a pervasive cooling event with a Northern Hemispheric extent approximately 9300 years ago. Coeval changes in the oceanic circulation of the North Atlantic imply freshwater forcing. However, the source, magnitude, and routing of meltwater have remained unknown. Located in central North America, Lake Superior is a key site for regulating the outflow of glacial meltwater to the oceans. Here, we show evidence for an approximately 45-meter rapid lake-level fall in this basin, centered on 9300 calibrated years before the present, due to the failure of a glacial drift dam on the southeast corner of the lake. We ascribe the widespread climate anomaly approximately 9300 years ago to this freshwater outburst delivered to the North Atlantic Ocean through the Lake Huron-North Bay-Ottawa River-St. Lawrence River valleys. PMID:20430972

  13. Exotic freshwater planarians currently known from Japan

    NARCIS (Netherlands)

    R. Sluys; M. Kawakatsu; K. Yamamoto

    2010-01-01

    Biogeographical and taxonomic information on the four non-indigenous freshwater planarians of Japan is reviewed, viz. Dugesia austroasiatica Kawakatsu, 1985, Girardia tigrina (Girard, 1850), G. dorotocephala (Woodworth, 1897), and Rhodax evelinae? Marcus, 1947. The occurrence of Girardia dorotocepha

  14. Adaptive diversity: hormones and metabolism in freshwaters.

    Science.gov (United States)

    Laudet, Vincent

    2010-12-01

    Genes underlying the evolution of morphological traits have recently been identified in a number of model species. In the stickleback, the metabolic adaptations to a freshwater habitat have now been linked to a well-known hormonal system. PMID:21145015

  15. Geographic Routing on Improved Coordinates

    OpenAIRE

    Brandes, Ulrik; Fleischer, Daniel

    2007-01-01

    We consider routing methods for networks when geographic positions of nodes are available. Instead of using the original geographic coordinates, however, we precompute virtual coordinates using barycentric layout. Combined with simple geometric routing rules, this greatly reduces the lengths of routes and outperforms algorithms working on the original coordinates. Along with experimental results we proof properties such as guaranteed message delivery and worst-case optimality. Our methods app...

  16. Alternative routes of insulin delivery

    Institute of Scientific and Technical Information of China (English)

    Ranjith K. Krishnankutty; Aju Mathew; Saikiran K. Sedimbi; Shrikumar Suryanarayan; Carani B. Sanjeevi

    2009-01-01

    Parenteral route of insulin administration has been the mode of treatment for all Type 1 diabetics and Type 2 diabetics with complications. Patient compliance has really been a major concern for this route of administration. Several alternative routes of administration are under consideration for effective glycemic control, including oral, inhaled, buccal, nasal, and patch routes. One of the approaches involving inhaled insulin has now reached the market. Several other candidates may reach the market in the near future, the promising one being oral insulin.

  17. A Primer of Multicast Routing

    CERN Document Server

    Rosenberg, Eric

    2012-01-01

    Whereas unicast routing determines a path from one source node to one destination node, multicast routing determines a path from one source to many destinations, or from many sources to many destinations. We survey multicast routing methods for when the set of destinations is static, and for when it is dynamic. While most of the methods we review are tree based, some non-tree methods are also discussed. We survey results on the shape of multicast trees, delay constrained multicast routing, aggregation of multicast traffic, inter-domain multicast, and multicast virtual private networks. We focu

  18. Freshwater Commercial Bycatch: an Understated Conservation Problem

    Energy Technology Data Exchange (ETDEWEB)

    Raby, Graham D.; Colotelo, Alison HA; Blouin-Demers, Gabriel; Cooke, Steven J.

    2011-04-01

    Commercial fisheries bycatch in marine systems has been regarded as a global conservation concern by environmental groups, scientists, government, and the public for decades. Fortunately, some headway has been made to mitigate the negative impacts of bycatch in marine environments. In a survey of the literature, we found that despite freshwater commercial fisheries yields comprising 11% of the global commercial catch, bycatch research focusing on freshwater commercial fisheries represented only {approx}3% of the total bycatch literature. This paucity of research is particularly alarming given that freshwater animals and habitats are some of the world's most imperiled. The limited inland bycatch literature that does exist includes examples of population declines attributed to commercial bycatch (e.g., freshwater dolphins in the Yangtze River in China) and illustrates that in some systems bycatch can be substantial (e.g., lake trout bycatch in the Laurentian Great Lakes). Encouraging results from the marine realm can serve as models for bycatch research in freshwater, and lead to measurable gains in conservation of freshwater ecosystems. We summarize existing work on inland bycatch in an effort to draw attention to this understated and understudied conservation problem.

  19. COMMUNITY DEVELOPMENT IN FRESHWATER MICROCOSMS

    Energy Technology Data Exchange (ETDEWEB)

    Rees, John T.

    1978-01-01

    Two cylindrical freshwater microcosms with a volume of 700 {ell} were maintained under controlled laboratory conditions for 190 days. The two microcosms were identical with regard to initial chemical composition and biological inocula, with the exceptions that in one microcosm (designated Tank 2) mosquitofish (Gambusia) and herbivorous catfish (Placostomas) were added. Three distinct communities developed in the tanks: (1) a phytoplankton-zooplankton assemblage and (2) two periphyton-zoobenthos communities associated with the sides and bottom of the tank, respectively. Community development and successional patterns were similar in both tanks. Major differences between the tanks involved timing of succession of the zooplankton and zoobenthos, attributable to predation by fish, principally Gambusia. A major drawback for these microcosms as use for experimental analogs such as lakes was a luxuriant periphyton growth which eventually overwhelmed the biomass of the system. The tanks displayed a degree of successional replicability, a large number of species, and a diversity of community development. Microcosms of this size could find use as experimental systems for higher level trophic manipulation and observation of life cycles not amenable to field studies.

  20. Route Elimination Heuristic for Vehicle Routing Problem with Time Windows

    Directory of Open Access Journals (Sweden)

    Sándor Csiszár

    2005-11-01

    Full Text Available The paper deals with the design of a route elimination (RE algorithm for thevehicle routing problem with time windows (VRPTW. The problem has two objectives, oneof them is the minimal number of routes the other is the minimal cost. To cope with theseobjectives effectively two-phase solutions are often suggested in the relevant literature. Inthe first phase the main focus is the route elimination, in the second one it is the costreduction. The algorithm described here is a part of a complete VRPWT study. The methodwas developed by studying the graph behaviour during the route elimination. For thispurpose a model -called “Magic Bricks” was developed. The computation results on theSolomon problem set show that the developed algorithm is competitive with the best ones.

  1. Qos Routing Scheme and Route Repair in WSN

    Directory of Open Access Journals (Sweden)

    M. Belghachi

    2013-01-01

    Full Text Available During the last decade, a new type of wireless network has evoked great interest among the scientific community; it is the wireless sensor networks (WSN. The WSN are used in various social activities, such as industrial processes, military surveillance applications, observation and monitoring of habitat, etc... This diversity of applications brings these networks to support different types of traffic and to provide services that must be both generic and adaptive for applications, the properties of the quality of service (QoS are different from one application to another. However, the need to minimize energy consumption has been the most important field of WSNs research. Few studies in the field are concerned with mechanisms for efficiently delivering QoS at the application level from network level metrics and connection such as delay or bandwidth, while minimizing the energy consumption of sensor nodes that are part of network. The idea is to ensure QoS through a routing process, which can detect paths that meet the QoS requirements based on ant colony optimization (ACOs, coupled with detected routes reservation process. However, it is necessary to integrate to this diagram the maintenance of route disrupted during communication. We propose a method that aims to improve the probability of success of a local route repair. This method based on the density of nodes in the vicinity of a route, as well as on the availability of this vicinity. Taking into account these parameters in the route selection phase (end of the routing process allows selecting among multiple routes, the one which is potentially the most easily repairable. In addition, we propose a method for early detection of the failure of a local route repair. This method can directly trigger a process of global re-routing that better fits to restore communication between the source and destination.

  2. Benefits Analysis of Multi-Center Dynamic Weather Routes

    Science.gov (United States)

    Sheth, Kapil; McNally, David; Morando, Alexander; Clymer, Alexis; Lock, Jennifer; Petersen, Julien

    2014-01-01

    Dynamic weather routes are flight plan corrections that can provide airborne flights more than user-specified minutes of flying-time savings, compared to their current flight plan. These routes are computed from the aircraft's current location to a flight plan fix downstream (within a predefined limit region), while avoiding forecasted convective weather regions. The Dynamic Weather Routes automation has been continuously running with live air traffic data for a field evaluation at the American Airlines Integrated Operations Center in Fort Worth, TX since July 31, 2012, where flights within the Fort Worth Air Route Traffic Control Center are evaluated for time savings. This paper extends the methodology to all Centers in United States and presents benefits analysis of Dynamic Weather Routes automation, if it was implemented in multiple airspace Centers individually and concurrently. The current computation of dynamic weather routes requires a limit rectangle so that a downstream capture fix can be selected, preventing very large route changes spanning several Centers. In this paper, first, a method of computing a limit polygon (as opposed to a rectangle used for Fort Worth Center) is described for each of the 20 Centers in the National Airspace System. The Future ATM Concepts Evaluation Tool, a nationwide simulation and analysis tool, is used for this purpose. After a comparison of results with the Center-based Dynamic Weather Routes automation in Fort Worth Center, results are presented for 11 Centers in the contiguous United States. These Centers are generally most impacted by convective weather. A breakdown of individual Center and airline savings is presented and the results indicate an overall average savings of about 10 minutes of flying time are obtained per flight.

  3. Perception bias in route choice

    NARCIS (Netherlands)

    Vreeswijk, J.D.; Thomas, T.; Berkum, van E.C.; Arem, van B.

    2014-01-01

    Travel time is probably one of the most studied attributes in route choice. Recently, perception of travel time received more attention as several studies have shown its importance in explaining route choice behavior. In particular, travel time estimates by travelers appear to be biased against non-

  4. Producing gestures facilitates route learning.

    Directory of Open Access Journals (Sweden)

    Wing Chee So

    Full Text Available The present study investigates whether producing gestures would facilitate route learning in a navigation task and whether its facilitation effect is comparable to that of hand movements that leave physical visible traces. In two experiments, we focused on gestures produced without accompanying speech, i.e., co-thought gestures (e.g., an index finger traces the spatial sequence of a route in the air. Adult participants were asked to study routes shown in four diagrams, one at a time. Participants reproduced the routes (verbally in Experiment 1 and non-verbally in Experiment 2 without rehearsal or after rehearsal by mentally simulating the route, by drawing it, or by gesturing (either in the air or on paper. Participants who moved their hands (either in the form of gestures or drawing recalled better than those who mentally simulated the routes and those who did not rehearse, suggesting that hand movements produced during rehearsal facilitate route learning. Interestingly, participants who gestured the routes in the air or on paper recalled better than those who drew them on paper in both experiments, suggesting that the facilitation effect of co-thought gesture holds for both verbal and nonverbal recall modalities. It is possibly because, co-thought gesture, as a kind of representational action, consolidates spatial sequence better than drawing and thus exerting more powerful influence on spatial representation.

  5. Producing gestures facilitates route learning.

    Science.gov (United States)

    So, Wing Chee; Ching, Terence Han-Wei; Lim, Phoebe Elizabeth; Cheng, Xiaoqin; Ip, Kit Yee

    2014-01-01

    The present study investigates whether producing gestures would facilitate route learning in a navigation task and whether its facilitation effect is comparable to that of hand movements that leave physical visible traces. In two experiments, we focused on gestures produced without accompanying speech, i.e., co-thought gestures (e.g., an index finger traces the spatial sequence of a route in the air). Adult participants were asked to study routes shown in four diagrams, one at a time. Participants reproduced the routes (verbally in Experiment 1 and non-verbally in Experiment 2) without rehearsal or after rehearsal by mentally simulating the route, by drawing it, or by gesturing (either in the air or on paper). Participants who moved their hands (either in the form of gestures or drawing) recalled better than those who mentally simulated the routes and those who did not rehearse, suggesting that hand movements produced during rehearsal facilitate route learning. Interestingly, participants who gestured the routes in the air or on paper recalled better than those who drew them on paper in both experiments, suggesting that the facilitation effect of co-thought gesture holds for both verbal and nonverbal recall modalities. It is possibly because, co-thought gesture, as a kind of representational action, consolidates spatial sequence better than drawing and thus exerting more powerful influence on spatial representation. PMID:25426624

  6. Security Consideration With Dynamic Routing

    Directory of Open Access Journals (Sweden)

    VISWESWARARAO BOLLA

    2012-03-01

    Full Text Available One of the major issues for data communication over wired and wireless networks is the security. the past work is on the designs of cryptography algorithms and system infrastructures. Dynamic routing algorithm called improved dynamic routing with security consideration, which is based on the concept of Zone Routing Protocol (ZRP that could randomize delivery paths for data transmission. The algorithm is easy to implement and compatible with popular routing protocols, such as the Routing Information Protocol (RIP in wired networks and Destination-Sequenced Distance Vector (DSDV protocol in wireless networks, without introducing extra control messages. This algorithm is mainly proposed to improve the and to overcome the limitations existing with the present cryptographic algorithms and protocols. Although some designs like IP security, Secure Socket Layer provide essential security, E-Mail security they unavoidably introduce substantial overheads in the Gateway/Host performance and effective network bandwidths.

  7. Stochastic Vehicle Routing with Recourse

    CERN Document Server

    Goertz, Inge Li; Saket, Rishi

    2012-01-01

    We study the classic Vehicle Routing Problem in the setting of stochastic optimization with recourse. StochVRP is a two-stage optimization problem, where demand is satisfied using two routes: fixed and recourse. The fixed route is computed using only a demand distribution. Then after observing the demand instantiations, a recourse route is computed -- but costs here become more expensive by a factor lambda. We present an O(log^2 n log(n lambda))-approximation algorithm for this stochastic routing problem, under arbitrary distributions. The main idea in this result is relating StochVRP to a special case of submodular orienteering, called knapsack rank-function orienteering. We also give a better approximation ratio for knapsack rank-function orienteering than what follows from prior work. Finally, we provide a Unique Games Conjecture based omega(1) hardness of approximation for StochVRP, even on star-like metrics on which our algorithm achieves a logarithmic approximation.

  8. Freshwater budget of the Canada Basin, Arctic Ocean, from salinity, δ18O, and nutrients

    Science.gov (United States)

    Yamamoto-Kawai, M.; McLaughlin, F. A.; Carmack, E. C.; Nishino, S.; Shimada, K.

    2008-01-01

    The contribution of freshwater components (e.g., meteoric, sea ice, and Pacific water) in the Canada Basin is quantified using salinity, δ18O, and nutrient data collected in 2003 and 2004. The penetration depth of sea ice meltwater is limited to the upper 30 m, and brine, rejected during sea ice formation, is observed from 30 to 250 m depth. The fraction of meteoric water is high in the upper 50 m and decreases with depth. Pacific water entering via Bering Strait is the main source of freshwater below 50 m depth. Bering Strait throughflow, which transports Pacific water with salinity 32.5 together with meteoric water supplied upstream of the Bering Strait, contributes up to 75% of freshwater input (>3200 km3 a-1) to the Canada Basin. The mean residence time of Pacific water in the Canada Basin is estimated to be 11 years. Precipitation and river runoff from both North American and Eurasian continents add >800 km3 a-1 and sea ice formation removes export of ice and liquid fresh water from the Canada Basin contributes ˜40% of the freshwater flux from the Arctic Ocean to the North Atlantic Ocean.

  9. Freshwater Availability and Constraints on Thermoelectric Power Generation in the Southeast U.S

    International Nuclear Information System (INIS)

    There is a myriad of uses to which our country's freshwater supply is currently committed. Together with increasing quantities of consumption, there are growing constraints on water availability. In our future there will be two elements of consumption at the forefront of concern: availability and efficiency. Availability of freshwater is the most important of these and is the subject of this report. To use water efficiently, we must first have it. Efficiency is key to ensuring availability for future needs. As population grows and economic and technology demands increase - especially for thermoelectric power - needs for freshwater will also increase. Thus, using our limited supplies of freshwater must be done as efficiently as possible. Thermoelectric generating industry is the largest user of our nation's water resources, including fresh, surface, ground, and saline water. Saline water use accounts for approximately 30% of thermoelectric use, while the remaining 70% is from freshwater sources. The U.S. Geological Survey (USGS) estimates that thermoelectric generation accounts for roughly 136,000 million gallons per day (MGD), or 39% of freshwater withdrawals. This ranks slightly behind agricultural irrigation as the top source of freshwater withdrawals in the U.S. in 2000. For Americans to preserve their standard of living and maintain a thriving economy it is essential that greater attention be paid to freshwater availability in efforts to meet energy demands - particularly for electric power. According to projections by the Energy Information Administration's (EIA) Annual Energy Outlook 2006 (AEO 2006) anticipated growth of thermoelectric generating capacity will be 22% between 2005 and 2030. In the 2007 Report, EIA estimates that capacity to grow from approximately 709 GW in 2005 to 862 GW in 20303. These large increases in generating capacity will result in increased water demands by thermoelectric power plants and greater competition over water between the

  10. Freshwater Availability and Constraints on Thermoelectric Power Generation in the Southeast U.S.

    Energy Technology Data Exchange (ETDEWEB)

    David Feldman; Amanda Slough; Gary Garrett

    2008-06-01

    There is a myriad of uses to which our country's freshwater supply is currently committed. Together with increasing quantities of consumption, there are growing constraints on water availability. In our future there will be two elements of consumption at the forefront of concern: availability and efficiency. Availability of freshwater is the most important of these and is the subject of this report. To use water efficiently, we must first have it. Efficiency is key to ensuring availability for future needs. As population grows and economic and technology demands increase - especially for thermoelectric power - needs for freshwater will also increase. Thus, using our limited supplies of freshwater must be done as efficiently as possible. Thermoelectric generating industry is the largest user of our nation's water resources, including fresh, surface, ground, and saline water. Saline water use accounts for approximately 30% of thermoelectric use, while the remaining 70% is from freshwater sources. The U.S. Geological Survey (USGS) estimates that thermoelectric generation accounts for roughly 136,000 million gallons per day (MGD), or 39% of freshwater withdrawals. This ranks slightly behind agricultural irrigation as the top source of freshwater withdrawals in the U.S. in 2000. For Americans to preserve their standard of living and maintain a thriving economy it is essential that greater attention be paid to freshwater availability in efforts to meet energy demands - particularly for electric power. According to projections by the Energy Information Administration's (EIA) Annual Energy Outlook 2006 (AEO 2006) anticipated growth of thermoelectric generating capacity will be 22% between 2005 and 2030. In the 2007 Report, EIA estimates that capacity to grow from approximately 709 GW in 2005 to 862 GW in 20303. These large increases in generating capacity will result in increased water demands by thermoelectric power plants and greater competition over water

  11. Road Routes for Waste Disposal - MDC_RecyclingRoute

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This CURBSIDE RECYCLING ROUTES BOUNDARIES LAYER IS A polygon feature class created for the Miami-Dade Department of Solid Waste Management (DSWM). It contains the...

  12. CROATIAN FRESHWATER FISHERIES IN 1996.

    Directory of Open Access Journals (Sweden)

    Mirko Turk

    1997-07-01

    Full Text Available Data on the production and fish catch according to species, on the surface of the fish ponds, on the means of fish catching and on the distribution of the production and the catch in 1996 is presented. The surface area used for production of fish has decreased by 1357 ha or 11.99%. The total fish amount has decreased by 1,921.00 tons or 29.76%. The feeding coefficient is 4 kg (33.33% bigger compared to the previous year. The amount of the fertilizer used has decreased by 18.79%. The fry carp growing ponds make up 5.99% of the total fish pond surfaces, the young carp ponds 21.13%, and the ponds with consumption fish 71.53%. The total fish amount in the carp ponds was 376 kg/ha, and in the trout ponds it was 146.6 tons/ha. The most produced fish species is the carp with 82.21 %, followed by the trout with 8.57%, the herbivorous fish with 4.78%, while all the other fish species make up 4.44% of the entire production. In the structure of herbivorous fish the grass carp is leading with 64,28%, followed by the big head carp with 26.02% and the silver carp with 9.70%. Compared to the previous year the production of the trout and tench has somewhat increased, while the production of all the other species of fish has decreased. Fish catch in open waters has increased by 19.23% in comparison to the previous year. In the production and catch of the total freshwater fish, carp made up 77.46%, the herbivorous fish made up 4.32%, trout 4.32%, sheat fish, pike perch and pike 2.99% and all other fish species 7.36%. As far as the distribution of production and catch is concerned, 46.91% were sold on the market, 39.19% were used for reproduction (stocking the fish farms, mortalities were 6.23%, and for personal use (sports fishing 7.67% was used. The number of fisheries workers has decreased by 17.75%, and the production per worker has also decreased by 26.62%, compared to the previous year. Average production per worker was 5.87 tons of fish.

  13. CROATIAN FRESHWATER FISHERIES IN 1997

    Directory of Open Access Journals (Sweden)

    Mirko Turk

    1998-10-01

    Full Text Available Data on the production and fish catch according to species, on the surface of the fish ponds, on the means of fish catching and on the distribution of the production and the catch in 1997 is presented. The surface area used for production of fish has decreased for 836 ha or 8.40%. The total fish amount was bigger for 477 tons, or 10,52%. The feeding coefficient is 2.6 kg decreased 35% for in comparison to the bigger compared to the previous year. The amount of the fertilizer used is bigger for 37.30%. The fry carp growing ponds make up 6.50% of the total fish pond surfaces, the young carp ponds 22.04/0, and the ponds with consumption fish 70.31%. The total amount in the carp ponds was 446 kg/ha, and in the trout ponds it was 160.8 tons/ha. The most produced fish species is the carp with 79.32%, followed by the trout with 11.50%, the herbivorous fish with 4.25%, while all the other fish species make up 4.93% of the entire production. In the structure of herbivorous fish the grass carp is leading with 69,23%, followed by the big head carp with 29.74% and the silver carp with 1.03%. Compared to the previous year the production of the carp, grass carp and tench is increased. Fish catch in open waters has decreased by 5.53% in comparison to the previous year. In the production and catch of the total freshwater fish, carp made up 75.34%, herbivorous fish made up 3.89%, trout 10.66%, sheat fish, pike perch and pike 2.70% and all other fish species 7.41%. As far as the distribution of production and catch of fish is concerned, 52,80% were sold on the market, 37.94% were used for reproduction (stocking the fish farms, mortality was 1.43%, and for personal use (sports fishing 7.83%. The number of fisheries workers has decreased for 8.17%, and the production per worker is bigger for 22.25%, compared to the previous year. Average production per worker was 7.17% tons of fish.

  14. Critical Route Network for Earthquake Response and Dynamic Route Analysis

    OpenAIRE

    Peeta, Srinivas; Kalafatas, Georgios

    2007-01-01

    Earthquakes can significantly disrupt societal functioning, cause ecological damage, and lead to loss of human lives and property, warranting a coordinated and efficient response to mitigate their negative impacts. Preparedness against earthquakes entails a pre-disaster planning aspect and a post disaster operational aspect. In the JTRP study “Emergency Earthquake Routes for the State of Indiana; Part I: Criteria for Selection of Primary Routes: Transportation Aspects”, a multicommodity maxim...

  15. Capacity Constrained Routing Algorithms for Evacuation Route Planning

    OpenAIRE

    Shekhar, Shashi; George, Betsy; Lu, Qingsong

    2010-01-01

    Efficient tools are needed to identify routes and schedules to evacuate affected populations to safety in face of natural disasters or terrorist attacks. Challenges arise due to violation of key assumptions (e.g. stationary ranking of alternative routes, Wardrop equilibrium) behind popular shortest path algorithms (e.g. Dijktra's, A*) and microscopic traffic simulators (e.g. DYNASMART). Time-expanded graphs (TEG) based mathematical programming paradigm does not scale up to large urban scenari...

  16. Ecosystem Services : In Nordic Freshwater Management

    DEFF Research Database (Denmark)

    Magnussen, Kristin; Hasler, Berit; Zandersen, Marianne

    Human wellbeing is dependent upon and benefit from ecosystem services which are delivered by well-functioning ecosystems. Ecosystem services can be mapped and assessed consistently within an ecosystem service framework. This project aims to explore the use and usefulness of the ecosystem service...... framework in freshwater management, particularly water management according to the Water Framework Directive (WFD). There are several examples of how ecosystem services have been used in WFD related studies in all the Nordic countries. Most of them involve listing, describing and categorizing freshwater...... ecosystem services, while there are few comprehensive Cost Benefit Analyses and analyses of disproportionate costs that apply this framework. More knowledge about ecosystem services and the value of ecosystem services for freshwater systems is needed....

  17. Protocol Independent Adaptive Route Update for VANET

    OpenAIRE

    Asim Rasheed; Sana Ajmal; Amir Qayyum

    2014-01-01

    High relative node velocity and high active node density have presented challenges to existing routing approaches within highly scaled ad hoc wireless networks, such as Vehicular Ad hoc Networks (VANET). Efficient routing requires finding optimum route with minimum delay, updating it on availability of a better one, and repairing it on link breakages. Current routing protocols are generally focused on finding and maintaining an efficient route, with very less emphasis on route update. Adaptiv...

  18. Effects of Pollution on Freshwater Organisms.

    Science.gov (United States)

    Choudri, B S; Baawain, Mahad

    2016-10-01

    This review includes works published in the general scientific literature during 2015 on the effects of anthropogenic pollutants on freshwater organisms. It begins with two broad sections: research reviews and broad field studies and surveys. This is followed by reviews of research categorized in sections to reflect the pollutant class. These sections include wastewater, stormwater and non-point source pollution, nutrients, sediment cap materials and suspended clays, botanical extracts, surfactants, metals, persistent organic pollutants, pharmaceuticals, endocrine disruptors, pesticides, petroleum hydrocarbons and polycyclic aromatic hydrocarbons (PAHs), ionic liquids, and nanomaterials. The final section includes works describing innovations in the field of freshwater pollution research. PMID:27620107

  19. Local Routing in Convex Subdivisions

    DEFF Research Database (Denmark)

    Bose, Prosenjit; Durocher, Stephane; Mondal, Debajyoti;

    2015-01-01

    In various wireless networking settings, node locations determine a network’s topology, allowing the network to be modelled by a geometric graph drawn in the plane. Without any additional information, local geometric routing algorithms can guarantee delivery to the target node only in restricted...... classes of geometric graphs, such as triangulations. In order to guarantee delivery on more general classes of geometric graphs (e.g., convex subdivisions or planar subdivisions), previous local geometric routing algorithms required Θ(logn) state bits to be stored and passed with the message. We present...... the first local geometric routing algorithm using only one state bit to guarantee delivery on convex subdivisions and the first local geometric memoryless routing algorithm that guarantees delivery on edge-augmented monotone subdivisions (including all convex subdivisions) when the algorithm has knowledge...

  20. Route Optimization in Network Mobility

    Directory of Open Access Journals (Sweden)

    Md. Hasan Tareque

    2013-01-01

    Full Text Available NEtwork MObility (NEMO controls mobility of a number of mobile nodes in a comprehensive way using one or more mobile routers. To choose a route optimization scheme, it is very important to have a quantitative comparison of the available route optimization schemes. The focus of this paper is to analyze the degree of Route Optimization (RO, deploy-ability and type of RO supported by each class in general. The comparison shows the differences among the schemes in terms of issues, such as additional header, signaling and memory requirement. We classify the schemes established on the basic method for route optimization, and equal the schemes based on protocol overhead, such as header overhead, amount of signaling, and memory requirements. Lastly the performance of the classes of different schemes has to be estimated under norms such as available bandwidth, topology of the mobile network and mobility type.

  1. Threatened and Endangered Freshwater Fish and Mussel Species Richness

    Data.gov (United States)

    U.S. Environmental Protection Agency — These data represent predicted current distributions of all US listed Threatened and Endangered freshwater fish and freshwater mussels in the Middle-Atlantic...

  2. Dynamic Routing with Security Considerations

    Directory of Open Access Journals (Sweden)

    G. Murali

    2011-11-01

    Full Text Available Now-a-days one of the major issues for data communication over wired and wireless networks is the security. the past work is on the designs of cryptography algorithms and system infrastructures. Apart from that we will propose a dynamic routing algorithm that could randomize delivery paths for data transmission. The algorithm is easy to implement and compatible with popular routing protocols, such as the Routing Information Protocol(RIP in wired networks and Destination-Sequenced Distance Vector(DSDV protocol in wireless networks, without introducing extra control messages. A clear study on the proposed algorithm is presented, and a series of simulation experiments are conducted to verify the results and to show the capability of the proposed algorithm. This algorithm is mainly proposed to improve the security and to overcome the limitations existing with the present cryptographic algorithms and protocols. Although some designs like IP security, Secure Socket Layer provide essential security, they unavoidably introduce substantial overheads in the Gateway/Host performance and effective network bandwidths. This routing protocol is compatible with the Routing Information Protocol which uses hop-count as its Routing metric. So there will be a limited number of hops and data transmissions are done by selecting hops randomly in a network. This improves security as well as controls traffic in the network. So, the procedure also includes using the multipath routing to select the paths to be followed. It uses the randomization process for selecting the number of hops to be selected for transforming the data. The routing table in this algorithm is based on the well-known Bellman-Ford algorithm. So, this overcomes the problems with security and traffic occurred with increase in the number of networks in these days

  3. New TPG bus route 28

    CERN Multimedia

    2003-01-01

    Geneva's Public Transport services (TPG) have recently inaugurated a new bus line 28, connecting the La Tour Hospital in Meyrin to the international organisations in Geneva, via the airport. All signs associated with this route will be yellow in colour. Timetables and route details can be found at http://www.tpg.ch. Relations with the Host States Service http://www.cern.ch/relations/ Tel. 72848

  4. CROATIAN FRESHWATER FISHERIES IN 1994

    Directory of Open Access Journals (Sweden)

    Mirko Turk

    1995-09-01

    Full Text Available Data on the production and catch of fish according to species, on the surface of the fish ponds, on the means of fish catching and on the distribution of the product and catch in 1994 is presented. The surface area used for production of fish has decreased by 274 ha or 2,51%. The total amount of fish has decreased by 1.263 tons or 14,78%. The highest production of fish was reached by the fish farm Donji Miholjac with 1.231 kg/ha. The feeding coefficient is 3,10 kg. Only on one fish farm was the feeding coefficient less than 2.0 kg (1,40 and on two large farms this coefficient was greater than 5,00 kg. The main fish food is still wheat followed by corn. The amount of fertilizer used was decreased by 14,40%. The fry carp growing ponds make up 0,92% of the surface area of the entire fish farm, the young carp ponds 21,77% and the culturing ponds for consumption fish 76,55%. The total amount of fish in the carp ponds was 660 kg/ha, and in the trout ponds it was 123.4 tons/ha. The carp is the highest produced fish with 80, 35%, then the herbivorous fish with 5,65 and all other fish make up 14% of the total production. In the structure of herbivorous fish the grass carp is leading with 54, 70%, followed by the big head carp with 25,54% and the silver carp with 19,76%. In comparison with the previous year the production of "all other fish- has significantly increased (287%, and sheat fish 18,90%, while the production of trench has decreased (71%. Fish catch in open waters has increased by 20,57% in comparison to the previous year. Carp made up 78,07% of the total production and catch of freshwater fish, the herbivorous fish made up 5,40%, trout 4,38%, the sheat fish, pike perch and pike 2,86% and all other fish species 9,28%. As far as the distribution of production and catch, 51,60% were sold on the market, 37,54% were used for reproduction (stocking the fish farms , mortalities were 6,35% and for personal use (sports fishing 4,50% was used. The number

  5. CROATIAN FRESHWATER FISHERIES IN 1995

    Directory of Open Access Journals (Sweden)

    Mirko Turk

    1996-06-01

    Full Text Available The data on the production and catch of fish according to sorts, pond ackerage, fishing means as well as the distribution of production and catch in 1995 have been stated in the paper. Ackerages used for the fish production have been increased by 1710 acres or 6.51%; total fish prinos* is less for 1,252 tons or 17.05%. The highest production of fish was reched by the fish farm Donji Miholjac with 859 kg/ha. A nutritive coefficient is 3.0 kg and it is less by 3.22% compared with the previous year. The nutritive coefficient is less than 2.0 kg in three fish-farms but it is greater than 4.0 kg in five large fish farms. Mostly corn but also wheat dominate in fish nutrition. The fertilizers consumption has been reduced by 14.53%. Of total pond ackerage, growing fish farms occupy 1.25%, new fish farms occupy 17.90% and consumptive fish farms occupy 79.64%. Total fish production in carp ponds is 507 kg/ha and 136.1 ton/ha in trout ponds. With 84.33%, carp is the mostly produced fish sorts, herbivore fish follow it with 3.89% and the production of all other fish makes 11.78% of the total. With 83.97%, grass carp takes the first place in the structure of herbivore fish. It is followed by the big head carp with 9.28% and silver carp with 6.75%. The trout production has been slightly increased by 6. 3%. Pike has appeared again and all other fish sorts has been reduced. Fish catch in open water has been increased by 7.06% compared with the previous year. When we sum up total production and catch of fresh-water fish, we can conclude that carp contributes with 81.08%; herbivore fish with 3.67%; trouts with 5.53%; sheat-fish, pike-perch and pike with 2.74% and all other fish sorts with 6.98%. As to the distribution of production and catch, there has been 49.02% sold on markets, 38.02% has been spent on farm reproduction (set back in ponds, the percentage of mortalities is 7.90%. Sport fishers have spent 5.06% of fish. The number of employees has been reduced

  6. Protocol independent adaptive route update for VANET.

    Science.gov (United States)

    Rasheed, Asim; Ajmal, Sana; Qayyum, Amir

    2014-01-01

    High relative node velocity and high active node density have presented challenges to existing routing approaches within highly scaled ad hoc wireless networks, such as Vehicular Ad hoc Networks (VANET). Efficient routing requires finding optimum route with minimum delay, updating it on availability of a better one, and repairing it on link breakages. Current routing protocols are generally focused on finding and maintaining an efficient route, with very less emphasis on route update. Adaptive route update usually becomes impractical for dense networks due to large routing overheads. This paper presents an adaptive route update approach which can provide solution for any baseline routing protocol. The proposed adaptation eliminates the classification of reactive and proactive by categorizing them as logical conditions to find and update the route. PMID:24723807

  7. Vehicle Routing With User Generated Trajectory Data

    DEFF Research Database (Denmark)

    Ceikute, Vaida; Jensen, Christian S.

    Rapidly increasing volumes of GPS data collected from vehicles provide new and increasingly comprehensive insight into the routes that drivers prefer. While routing services generally compute shortest or fastest routes, recent studies suggest that local drivers often prefer routes that are neither...... shortest nor fastest, indicating that drivers value route properties that are diverse and hard to quantify or even identify. We propose a routing service that uses an existing routing service while exploiting the availability of historical route usage data from local drivers. Given a source and destination......, the service recommends a corresponding route that is most preferred by local drivers. It uses a route preference function that takes into account the number of distinct drivers and the number of trips associated with a route, as well as temporal aspects of the trips. The paper provides empirical studies...

  8. Evaluation of pathogenic fungi occurrence in traumatogenic structures of freshwater fish

    Directory of Open Access Journals (Sweden)

    Fabio Caetano Oliveira Leme

    2011-04-01

    Full Text Available INTRODUCTION: Fungal infections in human skin, such as sporotrichosis, can occur after fish induced trauma. This work aimed to identify fungi in freshwater fish that are pathogenic to humans. METHODS: Extraction of dental arches from Serrassalmus maculatus (piranha and Hoplias malabaricus (wolf fish, stings from Pimelodus maculatus (mandis catfish, dorsal fin rays from Plagioscion spp. (corvina and Tilapia spp., for culture in Mycosel agar. Some cultures were submitted to DNA extraction for molecular identification by sequencing ITS-5.8S rDNA. RESULTS: Cultures identified most yeast as Candida spp., while sequencing also permitted the identification of Phoma spp. and Yarrowia lipolytica. CONCLUSIONS: While the search for S. schenckii was negative, the presence of fungus of the genera Phoma and Candida revealed the pathogenic potential of this infection route. The genus Phoma is involved in certain forms of phaeohyphomycosis, a subcutaneous mycosis caused by dematiaceous fungi, with reports of infections in human organs and systems. Traumatizing structures of some freshwater fish present pathogenic fungi and this may be an important infection route that must be considered in some regions of Brazil, since there are a large number of a fisherman in constant contact with traumatogenic fish.

  9. Mathematical Explorations: Freshwater Scarcity: A Proportional Representation

    Science.gov (United States)

    King, Alessandra

    2014-01-01

    Middle school students' mathematical understanding benefits from connecting mathematics to other content areas in the curriculum. This month's activity explores the issue of the scarcity of freshwater, a natural resource (activity sheets are included). This activity concentrates on the critical areas mentioned in the Common Core State…

  10. Effects of Pollution on Freshwater Invertebrates.

    Science.gov (United States)

    Buikema, A. L., Jr.; Herricks, E. E.

    1978-01-01

    Presents a literature review of the effects of pollution on freshwater invertebrates, covering publications of 1976-77. Some of the areas covered are: (1) toxicant effects on invertebrates; (2) microcosm and community effects, and (3) biological control of aquatic life. A list of 123 references is also presented. (HM)

  11. Sulfate reduction and methanogenesis at a freshwater

    DEFF Research Database (Denmark)

    Iversen, Vibeke Margrethe Nyvang; Andersen, Martin Søgaard; Jakobsen, Rasmus

    is enriched in dissolved sulfide, methane and bicarbonate. Under normal conditions the seawater-freshwater interface is found at a depth of 4 m at the coastline and reaches the bottom of the aquifer 40 m inland. However, occasional flooding of the area occurs, introducing sulfate to the aquifer. Groundwater...

  12. Freshwater flux to Sermilik Fjord, SE Greenland

    Directory of Open Access Journals (Sweden)

    S. H. Mernild

    2010-10-01

    Full Text Available Terrestrial inputs of freshwater flux to Sermilik Fjord, SE Greenland, were estimated, indicating ice discharge to be the dominant source of freshwater. A freshwater flux of 40.4 ± 4.9×109 m3 y−1 was found (1999–2008, with an 85% contribution originated from ice discharge (65% alone from Helheim Glacier, 11% from terrestrial surface runoff (from melt water and rain, 3% from precipitation at the fjord surface area, and 1% from subglacial geothermal and frictional melting due to basal ice motion. The results demonstrate the dominance of ice discharge as a primary mechanism for delivering freshwater to Sermilik Fjord. Time series of ice discharge for Helheim Glacier, Midgård Glacier, and Fenris Glacier were calculated from satellite-derived average surface velocity, glacier width, and estimated ice thickness, and fluctuations in terrestrial surface freshwater runoff were simulated based on observed meteorological data. These simulations were compared and bias corrected against independent glacier catchment runoff observations. Modeled runoff to Sermilik Fjord was variable, ranging from 2.9 ± 0.4×109 m3 y−1 in 1999 to 5.9 ± 0.9×109 m3 y−1 in 2005. The sub-catchment runoff of the Helheim Glacier region accounted for 25% of the total runoff to Sermilik Fjord. The runoff distribution from the different sub-catchments suggested a strong influence from the spatial variation in glacier coverage, indicating high runoff volumes, where glacier cover was present at low elevations.

  13. Dynamic routing using maximal road capacity

    NARCIS (Netherlands)

    Rothkrantz, L.J.M.

    2015-01-01

    Current routing devices route an individual car driver from start to destination in the shortest time. In this paper we propose a routing algorithm, routing the whole population of car drivers in the shortest time. The algorithm is an adapted dynamic version of the shortest path algorithm of Dijkstr

  14. Compressed Transmission of Route Descriptions

    CERN Document Server

    Batz, Gernot Veit; Luxen, Dennis; Sanders, Peter

    2010-01-01

    We present two methods to compress the description of a route in a road network, i.e., of a path in a directed graph. The first method represents a path by a sequence of via edges. The subpaths between the via edges have to be unique shortest paths. Instead of via edges also via nodes can be used, though this requires some simple preprocessing. The second method uses contraction hierarchies to replace subpaths of the original path by shortcuts. The two methods can be combined with each other. Also, we propose the application to mobile server based routing: We compute the route on a server which has access to the latest information about congestions for example. Then we transmit the computed route to the car using some mobile radio communication. There, we apply the compression to save costs and transmission time. If the compression works well, we can transmit routes even when the bandwidth is low. Although we have not evaluated our ideas with realistic data yet, they are quite promising.

  15. Constraining the Sahara freshwater discharge during sapropel S5 time by a stable isotope record from the Greater Sirte

    Science.gov (United States)

    Zirks, Eleen; Kucera, Michal; Bachem, Paul; Schulz, Hartmut

    2016-04-01

    The Nile River and the Black Sea were long considered as the only significant eastern Mediterranean freshwater sources and therefore inferred as the primary agents promoting surface stratification associated with sapropel formation. Sapropel S5, deposited during the last interglacial, marks a time of possible movement of Homo sapiens out of Africa. Satellite images revealed the existence of ancient rivers that once ran through the Sahara desert and drained into the Gulf of Sirte. Anomalous Nd isotope records from sapropel S5 deposits indicate that these rivers may have been active during MIS 5e, implying another freshwater source into the eastern Mediterranean Sea during that period. To constrain the extent of freshwater discharge into the Mediterranean from the Kufrah River during MIS 5e, a new δ18O record of five planktonic foraminifera species was generated from sediment core GeoTü SL 96, located proximal to the assumed outflow of the Kufrah River. The record from core GeoTü SL 96 compared with seven other records from the eastern Mediterranean Sea reveal a pattern of oxygen isotope anomalies which implies that the Kufrah River delivered detectable amount of freshwater during the second part of sapropel S5. These results reinforce the hypothesis that Sahara river systems were active during MIS 5e, which has ramifications for the understanding of sapropel events, reconstruction of coastal landscape, and the better understanding of migration routes of early humans.

  16. CROATIAN FRESHWATER FISHERY IN 2001 and 2002

    Directory of Open Access Journals (Sweden)

    Irena Jahutka

    2003-09-01

    Full Text Available For each segment of freshwater fisheries — freshwater aquaculture, commercial and sport and recreational fisheries — there is a legal obligation for data submission to the Ministry of agriculture and forestry, Directorate of fisheries. Within the segments of commercial and sport and recreational fisheries the data submission obligation refers to the period beginning with the year 2003, while in the segment of aquaculture that obligation includes also the year 2002. Data collected for freshwater aquaculture contain the information on production of freshwater fish, total production areas, food, fertilizers and subsidies for freshwater fish farming. Data collected for commercial and sport and recreational fisheries contain the information on catch quantities and number of commercial and sport and recreational fishermen. Freshwater fish production in the year 2001 was 5,549. 50 tons, while the total fresh water fish production in the year 2002 decreased for 1.00% compared to the previous year, amounting to 5,501.07 tons. Although total fresh water fish production constantly decreases comparing to previous years, trout production has increased and the maximum production was noted in the year 2002. Total area of the freshwater fish farms in the year 2001 increased compared to the year 2000 for 2.14% amounting to 11,880.41 ha. Actual production area slightly increased in comparison to the previous year as well and amounted to 9,214.11 ha. In the year 2002 total area of freshwater fish farms was 11,491.29 ha, and 72.13% of that figure was the actual production area, that is 8,288.27 ha. Production per unit area in the year 2001 was 485.31 kg/ha for warm–water species and 280.44 t/ha for cold–water species. In the year 2002 production per unit area for warm–water species was 462.95 kg/ha, and for cold–water species 315.26 t/ha. During the year 2001, in total, 10,575.82 t of food was spent and 1,891 tons of fertilizers and lime, while in the

  17. Pelagic larval duration predicts extinction risk in a freshwater fish clade.

    Science.gov (United States)

    Douglas, Morgan; Keck, Benjamin P; Ruble, Crystal; Petty, Melissa; Shute, J R; Rakes, Patrick; Hulsey, C Darrin

    2013-01-01

    Pelagic larval duration (PLD) can influence evolutionary processes ranging from dispersal to extinction in aquatic organisms. Using estimates of PLD obtained from species of North American darters (Percidae: Etheostomatinae), we demonstrate that this freshwater fish clade exhibits surprising variation in PLD. Comparative analyses provide some evidence that higher stream gradients favour the evolution of shorter PLD. Additionally, similar to patterns in the marine fossil record in which lower PLD is associated with greater extinction probability, we found a reduced PLD in darter lineages was evolutionarily associated with extinction risk. Understanding the causes and consequences of PLD length could lead to better management and conservation of organisms in our increasingly imperiled aquatic environments.

  18. Optimization of OSPF Routing in IP Networks

    Science.gov (United States)

    Bley, Andreas; Fortz, Bernard; Gourdin, Eric; Holmberg, Kaj; Klopfenstein, Olivier; Pióro, Michał; Tomaszewski, Artur; Ümit, Hakan

    The Internet is a huge world-wide packet switching network comprised of more than 13,000 distinct subnetworks, referred to as Autonomous Systems (ASs) autonomous system AS . They all rely on the Internet Protocol (IP) internet protocol IP for transport of packets across the network. And most of them use shortest path routing protocols shortest path routing!protocols , such as OSPF or IS-IS, to control the routing of IP packets routing!of IP packets within an AS. The idea of the routing is extremely simple — every packet is forwarded on IP links along the shortest route between its source and destination nodes of the AS. The AS network administrator can manage the routing of packets in the AS by supplying the so-called administrative weights of IP links, which specify the link lengths that are used by the routing protocols for their shortest path computations. The main advantage of the shortest path routing policy is its simplicity, allowing for little administrative overhead. From the network engineering perspective, however, shortest path routing can pose problems in achieving satisfactory traffic handling efficiency. As all routing paths depend on the same routing metric routing!metric , it is not possible to configure the routing paths for the communication demands between different pairs of nodes explicitly or individually; the routing can be controlled only indirectly and only as a whole by modifying the routing metric. Thus, one of the main tasks when planning such networks is to find administrative link weights that induce a globally efficient traffic routing traffic!routing configuration of an AS. It turns out that this task leads to very difficult mathematical optimization problems. In this chapter, we discuss and describe exact integer programming models and solution approaches as well as practically efficient smart heuristics for such shortest path routing problems shortest path routing!problems .

  19. ACO based routing for MANETs

    CERN Document Server

    Arif, Mohammad

    2012-01-01

    Mobile ad hoc network (MANET) is a collection of wireless mobile nodes. It dynamically forms a temporary network without using any pre existing network infrastructure or centralized administration i.e. with minimal prior planning. All nodes have routing capabilities and forward data packets to other nodes in multi-hop fashion. As the network is dynamic, the network topology continuously experiences alterations during deployment. The biggest challenge in MANETs is to find a path between communicating nodes. The considerations of the MANET environment and the nature of the mobile nodes create further complications which results in the need to develop special routing algorithms to meet these challenges. Swarm intelligence, a bio-inspired technique, which has proven to be very adaptable in other problem domains, has been applied to the MANET routing problem as it forms a good fit to the problem. In ant societies the activities of the individuals are not regulated by any explicit form of centralized control but ar...

  20. Mesozooplankton affinities in a recovering freshwater estuary

    Science.gov (United States)

    Chambord, Sophie; Maris, Tom; Colas, Fanny; Van Engeland, Tom; Sossou, Akoko-C.; Azémar, Frédéric; Le Coz, Maïwen; Cox, Tom; Buisson, Laetitia; Souissi, Sami; Meire, Patrick; Tackx, Michèle

    2016-08-01

    Water quality of the Scheldt estuary (Belgium/The Netherlands) has considerably improved in recent years, especially in the upstream, freshwater reaches. Within the zooplankton community, the copepod Eurytemora affinis, typically abundant in brackish water and quasi-absent from freshwater before 2007, has since substantially developed in the latter, where it now represents 90% of the crustacean mesozooplankton community. Simultaneously, cyclopoid copepod abundance has greatly decreased, while cladoceran abundance did not change. The study aim was: 1) to verify if the zooplankton community described for the period 2007-2009 by Mialet et al. (2011) has stabilized until present, and 2) to look for the environmental conditions favouring E. affinis development and causing changes in the upstream freshwater zooplankton community. The 2002-2012 temporal evolution of the zooplankton distribution at three stations in the upstream freshwater Scheldt estuary was analyzed. Water quality remained better after 2007 than before, and some factors revealed continuous improvement in annual mean concentrations (e.g. increase in O2, decrease in BOD5 and NH4sbnd N concentration). The increase in oxygen and the decrease in NH4sbnd N concentration, together with low discharge during summer were the main environmental factors explaining the development and timing of E. affinis in the upstream freshwater reach. In this reach, E. affinis maximal abundance is shifted to higher temperatures (summer) compared to its typical maximum spring abundance peak in the brackish zone of the Scheldt estuary and in most temperate estuaries. The changes in zooplankton community followed a temporal and spatial gradient induced by the spatio-temporal evolution of water quality improvement. The most downstream station (3) allowed E. affinis development (oxygen concentration > 4 mg L-1; NH4sbnd N concentration oxygen, etc.), there is no clear cause for their decline. Water quality improvement in the freshwater

  1. Routing Algorithm Exploits Spatial Relations

    Science.gov (United States)

    Okino, Clayton; Jennings, Esther

    2004-01-01

    A recently developed routing algorithm for broadcasting in an ad hoc wireless communication network takes account of, and exploits, the spatial relationships among the locations of nodes, in addition to transmission power levels and distances between the nodes. In contrast, most prior algorithms for discovering routes through ad hoc networks rely heavily on transmission power levels and utilize limited graph-topology techniques that do not involve consideration of the aforesaid spatial relationships. The present algorithm extracts the relevant spatial-relationship information by use of a construct denoted the relative-neighborhood graph (RNG).

  2. le programme SET-Routes

    CERN Document Server

    CERN Audiovisual Service

    2009-01-01

    Les routes de la science sont plus escarpées pour les femmes Le programme SET-Routes, qui visait à sensibiliser les jeunes filles à l’intérêt des carrières scientifiques, a pris fin en avril. Porté par l’EMBL, l’EMBO et le CERN, il a mis en place un réseau de femmes scientifiques, des ambassadrices qui se sont rendues dans les établissements scolaires européens pour parler de leur parcours scientifique.

  3. Stochastic vehicle routing with recourse

    DEFF Research Database (Denmark)

    Gørtz, Inge Li; Nagarajan, Viswanath; Saket, Rishi

    2012-01-01

    instantiations, a recourse route is computed - but costs here become more expensive by a factor λ. We present an O(log2n ·log(nλ))-approximation algorithm for this stochastic routing problem, under arbitrary distributions. The main idea in this result is relating StochVRP to a special case of submodular...... orienteering, called knapsack rank-function orienteering. We also give a better approximation ratio for knapsack rank-function orienteering than what follows from prior work. Finally, we provide a Unique Games Conjecture based ω(1) hardness of approximation for StochVRP, even on star-like metrics on which our...

  4. Freshwater fishes of Bontebok National Park

    Directory of Open Access Journals (Sweden)

    I.A. Russell

    2001-08-01

    Full Text Available Fish assemblages were sampled at six sites in the Breede River in the Bontebok National Park during 1999 and 2000. A total of 380 fish from 12 species was recorded. Indigenous fish collected included one freshwater species (Barbus andrewi, two catodromous species (Anguilla mossambica, Myxus capensis. and three estuarine species (Gilchris- tella aestuaria, Monodactylusfalciformis, Mugil cephalus. Four of the species recorded were aliens (Tinea tinea, Lepomis macrochirus, Micropterus salmoides, Micropterus dolomieu and two species translocated from other South African rivers (Tilapia sparrmanii, Clarias gariepinus. A further two indigenous species (Sandelia capensis, Pseudobarbus biirchelli could potentially occur within the park, though the high abundance of alien predators means that there is little chance for recolonisation from tributaries higher in the Breede River system. There is little opportunity to meaningfully conserve most indigenous freshwater fish in Bontebok National Park.

  5. Freshwater fishes of Tsitsikamma National Park

    Directory of Open Access Journals (Sweden)

    I.A. Russell

    2002-12-01

    Full Text Available This study aimed to determine the distribution and relative abundance of freshwater fishes in the Tsitsikamma National Park. Fish assemblages in six river systems were sampled in 2001, with a total of 323 fish from eight species recorded. Indigenous fish collected included four freshwater species (Pseudobarbus afer, Pseudobarbus tenuis, Sandelia capensis, Anguilla mossambica, three estuarine species (Monodactylus falciformis, Caffrogobius gilchristi, Myxus capensis, and one alien (Micropterus salmoides. One additional indigenous species (Galaxias zebratus and two aliens (Salmo trutta, Oncorhynchus mykiss could potentially occur within the park. The topography and locality of the park presents a unique opportunity to meaningfully conserve the endangered P. tenuis as well as other fish characteristic of the eastern reaches of the Cape Floristic Region. Management action is required to minimise opportunities for further establishment and spread of alien fish species and to conserve indigenous fish assemblages within the park.

  6. Freshwater aquatic plant biomass production in Florida

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, K.R.; Sutton, D.L.; Bowes, G.

    1983-01-01

    About 8% (1.2 million ha) of the total surface area of Florida is occupied by freshwater. Many of these water bodies are eutrophic. Nutrients present in these water bodies can be potentially used to culture aquatic plants as a possible feedstock for methane production. This paper summarizes the results of known research findings on biomass production potential of freshwater aquatic plants in Florida and identifies key research needs to improve the quality and quantity of biomass yields. Among floating aquatic plants, biomass yield potential was in the order of water-hyacinth > water lettuce > pennywort > salvinia > duckweed > azolla. Pennywort, duckweed, and azolla appear to perform well during the cooler months compared to other aquatic plants. Among emergent plants, biomass yield potential was in the order of southern wild rice > cattails > soft rush > bulrush. Cultural techniques, nutrient management, and environmental factors influencing the biomass yields were discussed. 68 references.

  7. Freshwater fish of the Wilderness National Park

    Directory of Open Access Journals (Sweden)

    I.A. Russell

    1999-01-01

    Full Text Available The study aimed to determine the distribution and relative abundance of freshwater fish in the Wilderness National Park. Fish assemblages in the Touw and Duiwe rivers were sampled in 1997 and 1998, with a total of 327 fish from nine species recorded. Indigenous species included two freshwater species (Pseudobarbus afer, Sandelia capensis, two catadromous species (Anguilla mossambicus, Myxus capensis, and two estuarine species (Monodactylusfalciformis, Caffrogobius multifasciatus. Three of the nine recorded species were alien (Micropterus dolomieu, Micropterus salmoides, Gambusia affinis, with the Micropterus spp., in particular, likely to have a substantial negative influence on indigenous species. A further one indigenous species, two translocated indigenous species, and five estuarine species could potentially be recorded in these rivers. River catchment management actions to restore perennial flow to the Duiwe River, to prevent the attenuation of floods, and to prevent further establishment and spread of alien and translocated biota are required to conserve indigenous fish assemblages.

  8. Freshwater reservoir effect variability in Northern Germany

    DEFF Research Database (Denmark)

    Philippsen, Bente; Heinemeier, Jan

    2012-01-01

    The freshwater reservoir effect is a potential problem when radiocarbon dating fishbones, shells, human bones or food crusts on pottery from sites next to rivers or lakes. The reservoir age in rivers containing considerable amounts of dissolved 14C-free carbonates can be up to several thousand...... variability that can also be expected for the past. Water DIC from different seasons, and from the same season in different years, has been dated because it is the carbon source in photosynthesis and thus at the basis of the rivers’ food webs. The radiocarbon ages of underwater plants and different parts...... years and may be highly variable. For accurate radiocarbon dating of freshwater-based samples, the order of magnitude of the reservoir effect as well as the degree of variability has to be known. The initial problem in this case was the accurate dating of food crusts on pottery from the Mesolithic sites...

  9. Superhydrophobic resistance to dynamic freshwater biofouling inception.

    Science.gov (United States)

    Krishnan, K Ghokulla; Malm, Peter; Loth, Eric

    2015-01-01

    Superhydrophobic nanotextured surfaces have gained increased usage in various applications due to their non-wetting and self-cleaning abilities. The aim of this study was to investigate nanotextured surfaces with respect to their resistance to the inception of freshwater biofouling at transitional flow conditions. Several coatings were tested including industry standard polyurethane (PUR), polytetrafluoroethylene (PTFE), capstone mixed polyurethane (PUR + CAP) and nanocomposite infused polyurethane (PUR + NC). Each surface was exposed to freshwater conditions in a lake at 4 m s(-1) for a duration of 45 min. The polyurethane exhibited the greatest fouling elements, in terms of both height and number of elements, with the superhydrophobic nanocomposite based polyurethane (PUR + NC) showing very little to no fouling. A correlation between the surface characteristics and the degree of fouling inception was observed.

  10. Assessing the freshwater distribution of yellow eel

    Directory of Open Access Journals (Sweden)

    Lasne É.

    2009-04-01

    Full Text Available In the global context of the decline in wild species, modeling the distribution of populations is a crucial aspect of ecological management. This can be a major challenge, especially for species, such as the European eel, that have complex life cycles, exhibit cryptic behavior, or migrate over long distances. A review of the literature suggests that eel size data could be used to assess and analyze freshwater distribution of eel. We argue that analyses based on small yellow eels (≤ 300 mm along the longitudinal course of rivers could provide a valuable tool for population monitoring. We propose a standardized catchment recruitment index and a colonization index based on the probability of occurrence (presence/absence data using logistic models for different size classes. The model developed here provides a convenient guide for assessing yellow eel stages in freshwater areas, and should have concrete applications for management of the species.

  11. Effects of nano-titanium dioxide on freshwater algal population dynamics.

    Directory of Open Access Journals (Sweden)

    Konrad J Kulacki

    Full Text Available To make predictions about the possible effects of nanomaterials across environments and taxa, toxicity testing must incorporate not only a variety of organisms and endpoints, but also an understanding of the mechanisms that underlie nanoparticle toxicity. Here, we report the results of a laboratory experiment in which we examined how titanium dioxide nanoparticles impact the population dynamics and production of biomass across a range of freshwater algae. We exposed 10 of the most common species of North American freshwater pelagic algae (phytoplankton to five increasing concentrations of n-TiO(2 (ranging from controls to 300 mg n-TiO(2 L(-1. We then examined the effects of n-TiO(2 on the population growth rates and biomass production of each algal species over a period of 25 days. On average, increasing concentrations of n-TiO(2 had no significant effects on algal growth rates (p = 0.376, even though there was considerable species-specific variation in responses. In contrast, exposure to n-TiO(2 tended to increase maximum biomass achieved by species in culture (p = 0.06. Results suggest that titanium dioxide nanoparticles could influence certain aspects of population growth of freshwater phytoplankton, though effects are unlikely at environmentally relevant concentrations.

  12. Salmonid & freshwater Fisheries statistics England & Wales 1996

    OpenAIRE

    1997-01-01

    This is the Salmonid & Freshwater Fisheries Statistics for England & Wales 1996 produced by the Environment Agency in 1997. The principal aim of the Environment Agency in respect of fisheries is to maintain improve and develop fish stocks, the basic fisheries resource, in order to optimise the social and economic benefits from their sustainable exploitation. This report is the second collation of salmon and migratory trout catch statistics for England and Wales produced by the Environment Ag...

  13. Freshwater savings from marine protein consumption

    International Nuclear Information System (INIS)

    Marine fisheries provide an essential source of protein for many people around the world. Unlike alternative terrestrial sources of protein, marine fish production requires little to no freshwater inputs. Consuming marine fish protein instead of terrestrial protein therefore represents freshwater savings (equivalent to an avoided water cost) and contributes to a low water footprint diet. These water savings are realized by the producers of alternative protein sources, rather than the consumers of marine protein. This study quantifies freshwater savings from marine fish consumption around the world by estimating the water footprint of replacing marine fish with terrestrial protein based on current consumption patterns. An estimated 7 600 km3 yr−1 of water is used for human food production. Replacing marine protein with terrestrial protein would require an additional 350 km3 yr−1 of water, meaning that marine protein provides current water savings of 4.6%. The importance of these freshwater savings is highly uneven around the globe, with savings ranging from as little as 0 to as much as 50%. The largest savings as a per cent of current water footprints occur in Asia, Oceania, and several coastal African nations. The greatest national water savings from marine fish protein occur in Southeast Asia and the United States. As the human population increases, future water savings from marine fish consumption will be increasingly important to food and water security and depend on sustainable harvest of capture fisheries and low water footprint growth of marine aquaculture. (paper)

  14. Freshwater peat on the continental shelf

    Science.gov (United States)

    Emery, K.O.; Wigley, R.L.; Bartlett, A.S.; Rubin, M.; Barghoorn, E.S.

    1967-01-01

    Freshwater peats from the continental shelf off northeastern United States contain the same general pollen sequence as peats from ponds that are above sea level and that are of comparable radiocarbon ages. These peats indicate that during glacial times of low sea level terrestrial vegetation covered the region that is now the continental shelf in an unbroken extension from the adjacent land areas to the north and west.

  15. Dynamic Weather Routes Architecture Overview

    Science.gov (United States)

    Eslami, Hassan; Eshow, Michelle

    2014-01-01

    Dynamic Weather Routes Architecture Overview, presents the high level software architecture of DWR, based on the CTAS software framework and the Direct-To automation tool. The document also covers external and internal data flows, required dataset, changes to the Direct-To software for DWR, collection of software statistics, and the code structure.

  16. Genetic algorithms for route discovery.

    Science.gov (United States)

    Gelenbe, Erol; Liu, Peixiang; Lainé, Jeremy

    2006-12-01

    Packet routing in networks requires knowledge about available paths, which can be either acquired dynamically while the traffic is being forwarded, or statically (in advance) based on prior information of a network's topology. This paper describes an experimental investigation of path discovery using genetic algorithms (GAs). We start with the quality-of-service (QoS)-driven routing protocol called "cognitive packet network" (CPN), which uses smart packets (SPs) to dynamically select routes in a distributed autonomic manner based on a user's QoS requirements. We extend it by introducing a GA at the source routers, which modifies and filters the paths discovered by the CPN. The GA can combine the paths that were previously discovered to create new untested but valid source-to-destination paths, which are then selected on the basis of their "fitness." We present an implementation of this approach, where the GA runs in background mode so as not to overload the ingress routers. Measurements conducted on a network test bed indicate that when the background-traffic load of the network is light to medium, the GA can result in improved QoS. When the background-traffic load is high, it appears that the use of the GA may be detrimental to the QoS experienced by users as compared to CPN routing because the GA uses less timely state information in its decision making. PMID:17186801

  17. Genetic algorithms for route discovery.

    Science.gov (United States)

    Gelenbe, Erol; Liu, Peixiang; Lainé, Jeremy

    2006-12-01

    Packet routing in networks requires knowledge about available paths, which can be either acquired dynamically while the traffic is being forwarded, or statically (in advance) based on prior information of a network's topology. This paper describes an experimental investigation of path discovery using genetic algorithms (GAs). We start with the quality-of-service (QoS)-driven routing protocol called "cognitive packet network" (CPN), which uses smart packets (SPs) to dynamically select routes in a distributed autonomic manner based on a user's QoS requirements. We extend it by introducing a GA at the source routers, which modifies and filters the paths discovered by the CPN. The GA can combine the paths that were previously discovered to create new untested but valid source-to-destination paths, which are then selected on the basis of their "fitness." We present an implementation of this approach, where the GA runs in background mode so as not to overload the ingress routers. Measurements conducted on a network test bed indicate that when the background-traffic load of the network is light to medium, the GA can result in improved QoS. When the background-traffic load is high, it appears that the use of the GA may be detrimental to the QoS experienced by users as compared to CPN routing because the GA uses less timely state information in its decision making.

  18. How to choose the route.

    Science.gov (United States)

    Grecu, Irina

    2013-01-01

    Choosing the route for nutrition support delivery is one of the main steps in the algorithm of providing successful nutrition to the critically ill, but it is certainly not an easy process. The rationale should be guided not only by principles like physiology and benefit versus harm, but also by individual patient factors like feasibility, contraindications, predicted versus actual tolerance, and (most important) the timing for starting food delivery. Although oral nutrition is the more physiological route for feeding, it is seldom possible or sufficient in critically ill patients. Enteral nutrition, in the form of tube feeding, remains the best option in the absence of absolute contraindications, but many other factors should be taken into account. These include the importance of starting early and trying to achieve target nutrients delivery early, especially in previously undernourished or in most severely ill patients, as well as the gastrointestinal intolerance present in the majority of critically ill patients. Parenteral nutrition is an alternative route for nutrition delivery when the enteral one is impossible or insufficient. The most common complication when choosing this route is overfeeding, which has been associated with increased complications rate. On the other hand, the most common complication of enteral nutrition is underfeeding, which has also been associated with worse outcome and even increased mortality. Combining enteral with supplemental parenteral nutrition is therefore a rational approach for providing early and adequate nutritional support in the most severely ill patients.

  19. The routed inventory pooling problem

    NARCIS (Netherlands)

    Bouma, Harmen Willem

    2013-01-01

    In supply chains vloeit een groot deel van de kosten voort uit voorraden en transport. Om deze reden wordt veel onderzoek gedaan naar technieken en concepten die de voorraad- en transportkosten helpen te verlagen. Twee populaire onderzoeksgebieden zijn Inventory Routing, waarbij het doel is optimale

  20. ACO Based Routing for MANETs

    Directory of Open Access Journals (Sweden)

    Mohammad Arif

    2012-05-01

    Full Text Available Mobile ad hoc network (MANET is a collection of wireless mobile nodes. It dynamically forms atemporary network without using any pre existing network infrastructure or centralized administrationi.e. with minimal prior planning. All nodes have routing capabilities and forward data packets to othernodes in multi-hop fashion. As the network is dynamic, the network topology continuously experiencesalterations during deployment. The biggest challenge in MANETs is to find a path betweencommunicating nodes. The considerations of the MANET environment and the nature of the mobile nodescreate further complications which results in the need to develop special routing algorithms to meet thesechallenges. Swarm intelligence, a bio-inspired technique, which has proven to be very adaptable in otherproblem domains, has been applied to the MANET routing problem as it forms a good fit to the problem.In ant societies the activities of the individuals are not regulated by any explicit form of centralizedcontrol but are the result of self-organizing dynamics driven by local interactions and communicationsamong a number of relatively simple individuals. This unique characteristic has made ant societies anattractive and inspiring model for building new algorithms and new multi-agent systems. In this paper,we have studied and reviewed Ant Colony based routing algorithms and its variants. Finally, aperformance evaluation of the original ARA and the EARA is carried out with respect to each other.

  1. Pesticides in Brazilian freshwaters: a critical review.

    Science.gov (United States)

    Albuquerque, A F; Ribeiro, J S; Kummrow, F; Nogueira, A J A; Montagner, C C; Umbuzeiro, G A

    2016-07-13

    The widespread use of pesticides in agriculture can lead to water contamination and cause adverse effects on non-target organisms. Brazil has been the world's top pesticide market consumer since 2008, with 381 approved pesticides for crop use. This study provides a comprehensive literature review on the occurrence of pesticide residues in Brazilian freshwaters. We searched for information in official agency records and peer-reviewed scientific literature. Risk quotients were calculated to assess the potential risk posed to aquatic life by the individual pesticides based on their levels of water contamination. Studies about the occurrence of pesticides in freshwaters in Brazil are scarce and concentrated in few sampling sites in 5 of the 27 states. Herbicides (21) accounted for the majority of the substances investigated, followed by fungicides (11), insecticides (10) and plant growth regulators (1). Insecticides are the class of major concern. Brazil would benefit from the implementation of a nationwide pesticide freshwater monitoring program to support preventive, remediation and enforcement actions.

  2. THE DEVELOPMENT OF FRESHWATER FISHING IN ELAZIĞ

    Directory of Open Access Journals (Sweden)

    Zeki BOYRAZ

    2015-04-01

    Full Text Available Increasing world population has more demand for healthy food day after day. Our research draws attention to increasing freshwater fishery in Elazığ that increased its importance depending on the fishery activities in inland water in recent years. Our reasearch area, Elazığ, is situated in the Upper Fırat part, in the southwest of Eastern Anatolia Region. The main factor that allows freshwater fishery develop in the research field is the existence of fresh water. The most important river within the city borders is Fırat and its tributaries. Hazar Lake has a 86 km2 surface area and it is 30 km far from the city center. Also the Keban Dam, 675 km2 and Karakaya Dam, 268 km2 make up the city borders. Other important dams like Kralkızı, 57 km2 and Özlüce 26 km2 are situated in near distances. In this study we will focus on the potential and development of the freshwater fishery in Elazığ.

  3. Extraction of Freshwater and Energy from Atmosphere

    CERN Document Server

    Bolonkin, Alexander

    2007-01-01

    Author offers and researches a new, cheap method for the extraction of freshwater from the Earth atmosphere. The suggected method is fundamentally dictinct from all existing methods that extract freshwater from air. All other industrial methods extract water from a saline water source (in most cases from seawater). This new method may be used at any point in the Earth except Polar Zones. It does not require long-distance freshwater transportation. If seawater is not utilized for increasing its productivity, this inexpensive new method is very environment-friendly. The author method has two working versions: (1) the first variant the warm (hot) atmospheric air is lifted by the inflatable tube in a high altitude and atmospheric steam is condenced into freswater: (2) in the second version, the warm air is pumped 20-30 meters under the sea-surface. In the first version, wind and solar heating of air are used for causing air flow. In version (2) wind and propeller are used for causing air movment. The first method...

  4. Pesticides in Brazilian freshwaters: a critical review.

    Science.gov (United States)

    Albuquerque, A F; Ribeiro, J S; Kummrow, F; Nogueira, A J A; Montagner, C C; Umbuzeiro, G A

    2016-07-13

    The widespread use of pesticides in agriculture can lead to water contamination and cause adverse effects on non-target organisms. Brazil has been the world's top pesticide market consumer since 2008, with 381 approved pesticides for crop use. This study provides a comprehensive literature review on the occurrence of pesticide residues in Brazilian freshwaters. We searched for information in official agency records and peer-reviewed scientific literature. Risk quotients were calculated to assess the potential risk posed to aquatic life by the individual pesticides based on their levels of water contamination. Studies about the occurrence of pesticides in freshwaters in Brazil are scarce and concentrated in few sampling sites in 5 of the 27 states. Herbicides (21) accounted for the majority of the substances investigated, followed by fungicides (11), insecticides (10) and plant growth regulators (1). Insecticides are the class of major concern. Brazil would benefit from the implementation of a nationwide pesticide freshwater monitoring program to support preventive, remediation and enforcement actions. PMID:27367607

  5. Optimum Route Selection for Vehicle Navigation

    Directory of Open Access Journals (Sweden)

    Dalip

    2016-02-01

    Full Text Available The objective of Optimum Route Selection for Vehicle Navigation System (ORSVNS article is to develop a system, which provides information about real time alternate routes to the drivers and also helps in selecting the optimal route among all the alternate routes from an origin to destination. Two types of query systems, special and general, are designed for drivers. Here, the criterion for route selection is introduced using primary and secondary road attributes. The presented methodology helps the drivers in better decision making to choose optimal route using fuzzy logic. For experimental results ORSVNS is tested over 220 km portion of Haryana state in India.

  6. Operations Research for Freight Train Routing and Scheduling

    DEFF Research Database (Denmark)

    Harrod, Steven; Gorman, Michael F.

    2011-01-01

    This article describes the service design activities that plan and implement the rail freight operating plan. Elements of strategic service design include the setting of train frequency, the routing of cars among trains, and the consolidation of cars, called blocking. At the operational level......, trains are dispatched either according to train paths configured in advance, called timetables, or according to priority rules. We describe the North American and European practice along with selected modeling and problem solving methodologies appropriate for each of the operating conditions described...

  7. American Dream in Early American Literatuer

    Institute of Scientific and Technical Information of China (English)

    屈彩娥; 李小玺

    2008-01-01

    American dream has often been closely rehted to American literature.Many say that the American literary history can be seen as the history of American dreams.In most periods in history,writers,whose dreams have been infused in a variety of characters create the American literature.While in Early American literature,American dream had been presented in a dif-ferent way.

  8. Route Scherrer and Route Einstein closed for construction work

    CERN Multimedia

    2015-01-01

    Please note that Route Scherrer will be inaccessible for two and a half months from the beginning of March and that part of Route Einstein will be closed for two weeks from the end of February.   Figure 1. The part of Route Scherrer between Building 510 and Building 53 (see Figure 1) will be closed from the beginning of March until mid-May for civil engineering works.   The superheated water pipes supplying the buildings in this area date back to 1959 and therefore present a significant risk of leakage. In order to ensure the reliable supply of superheated water, and, by extension, heating, to all premises near the Main Building (i.e. Buildings 500, 501, 503, 60, 62, 63 and 64), a new buried service duct will be installed between the basements of Buildings 53 and 61 to house a new superheated water pipe. Figure 2. The following car parks will, however, remain accessible for the duration of the works: the Cèdres car park, the car park for Buildings 4 and 5, and the ca...

  9. Highway route controlled quantity shipment routing reports - An overview

    International Nuclear Information System (INIS)

    US Department of Transportation (DOT) regulations require a postnotification report from the shipper for all shipments of radioactive materials categorized as a Highway Route Controlled Quantity. These postnotification reports, filed in compliance with 49 CFR 172.203(d), have been compiled by the DOT in a database known as the Radioactive Materials Routing Report (RAMRT) since 1982. The data were sorted by each of its elements to establish historical records and trends of Highway Route Controlled Quantity shipments from 1982 through 1987. Approximately 1520 records in the RAMRT database were compiled for this analysis. Approximately half of the shipments reported for the study period were from the US Department of Energy (DOE) and its contractors, with the others being commercial movements. Two DOE installations, EG and G Idaho and Oak Ridge, accounted for nearly half of the DOE activities. Similarly, almost half of the commercial movements were reported by two vendors, Nuclear Assurance Corporation and Transnuclear, Incorporated. Spent fuel from power and research reactors accounted for approximately half of all shipments

  10. Vegetative community control of freshwater availability: Phoenix Islands case study

    Science.gov (United States)

    Engels, M.; Heinse, R.

    2014-12-01

    On small low islands with limited freshwater resources, terrestrial plant communities play a large role in moderating freshwater availability. Freshwater demands of vegetative communities are variable depending on the composition of the community. Hence, changes to community structure from production crop introductions, non-native species invasions, and climate change, may have significant implications for freshwater availability. Understanding how vegetative community changes impact freshwater availability will allow for better management and forecasting of limited freshwater supplies. To better understand these dynamics, we investigated three small tropical atolls in the Phoenix Island Protected Area, Kiribati. Despite their close proximity, these islands receive varying amounts of rainfall, are host to different plant communities and two of the islands have abandoned coconut plantations. Using electromagnetic induction, ground penetrating radar, soil samples, climate and satellite data, we present preliminary estimates of vegetative water demand for different tropical plant communities.

  11. Multipath Routing Protocol for Effective Local Route Recovery in Mobile Ad hoc Network

    Directory of Open Access Journals (Sweden)

    S. K. Srivatsa

    2012-01-01

    Full Text Available Problem statement: In mobile ad hoc networks, frequent mobility during the transmission of data causes route failure which results in route rediscovery. In this, we propose multipath routing protocol for effective local route recovery in Mobile Ad hoc Networks (MANET. In this protocol, each source and destination pair establishes multiple paths in the single route discovery and they are cached in their route caches. Approach: The cached routes are sorted on the basis of their bandwidth availability. In case of route failure in the primary route, a recovery node which is an overhearing neighbor, detects it and establishes a local recovery path with maximum bandwidth from its route cache. Results: By simulation results, we show that the proposed approach improves network performance. Conclusion: The proposed route recovery management technique prevents the frequent collision and degradation in the network performance.

  12. A simple web-based tool to compare freshwater fish data collected using AFS standard methods

    Science.gov (United States)

    Bonar, Scott A.; Mercado-Silva, Norman; Rahr, Matt; Torrey, Yuta T.; Cate, Averill

    2016-01-01

    The American Fisheries Society (AFS) recently published Standard Methods for Sampling North American Freshwater Fishes. Enlisting the expertise of 284 scientists from 107 organizations throughout Canada, Mexico, and the United States, this text was developed to facilitate comparisons of fish data across regions or time. Here we describe a user-friendly web tool that automates among-sample comparisons in individual fish condition, population length-frequency distributions, and catch per unit effort (CPUE) data collected using AFS standard methods. Currently, the web tool (1) provides instantaneous summaries of almost 4,000 data sets of condition, length frequency, and CPUE of common freshwater fishes collected using standard gears in 43 states and provinces; (2) is easily appended with new standardized field data to update subsequent queries and summaries; (3) compares fish data from a particular water body with continent, ecoregion, and state data summaries; and (4) provides additional information about AFS standard fish sampling including benefits, ongoing validation studies, and opportunities to comment on specific methods. The web tool—programmed in a PHP-based Drupal framework—was supported by several AFS Sections, agencies, and universities and is freely available from the AFS website and fisheriesstandardsampling.org. With widespread use, the online tool could become an important resource for fisheries biologists.

  13. A computerized image database for freshwater algae recorded in Turkey

    OpenAIRE

    Şen, Bülent; SÖNMEZ, Feray; ÇETİN, Ahmet Kadri; ALP, Mehmet Tahir; ÖZER, Tülay BAYKAL

    2015-01-01

    A computer-based image database for freshwater algae recorded in Turkey has been established. A separate page was prepared for each algal taxon and each page includes images and taxonomic and ecological information related to the taxon. Algal images were obtained mainly from authors of algal studies previously carried out in various freshwater bodies in Turkey. Data were then standardized in accordance with that of the central database of Turkish herbaria and a database for Turkish freshwater...

  14. Implications of dam obstruction for global freshwater fish diversity

    OpenAIRE

    Reidy Liermann, Catherine; Nilsson, Christer; Robertson, James; Ng, Rebecca

    2012-01-01

    Dams are obstructing rivers worldwide, impairing habitat and migration opportunities for many freshwater fish species; however, global data linking dam and fish distributions have been limited. Here, we quantify dam obstruction at the biogeographic scale of freshwater ecoregion, which provides the spatial framework necessary to assess the risk of fish species loss due to dams and allows us to identify both ecoregions and genera at risk. Nearly 50% of the 397 assessed freshwater ecoregions are...

  15. Restricted-Range Fishes and the Conservation of Brazilian Freshwaters

    OpenAIRE

    Cristiano Nogueira; Paulo A. Buckup; Menezes, Naercio A.; Osvaldo T. Oyakawa; Thais P Kasecker; Ramos Neto, Mario B.; da Silva, José Maria C.

    2010-01-01

    BACKGROUND: Freshwaters are the most threatened ecosystems on earth. Although recent assessments provide data on global priority regions for freshwater conservation, local scale priorities remain unknown. Refining the scale of global biodiversity assessments (both at terrestrial and freshwater realms) and translating these into conservation priorities on the ground remains a major challenge to biodiversity science, and depends directly on species occurrence data of high taxonomic and geograph...

  16. Tropical versus high latitude freshwater influence on the Atlantic circulation

    OpenAIRE

    Goelzer, H.; J. Mignot; Levermann, A; Rahmstorf, S.

    2006-01-01

    We investigate the model sensitivity of the Atlantic meridional overturning circulation (AMOC) to anomalous freshwater flux in the tropical and northern Atlantic. Forcing in both locations leads to the same qualitative response: a positive freshwater anomaly induces a weakening of the AMOC and a negative freshwater anomaly strengthens the AMOC. Strong differences arise in the temporal characteristics and amplitude of the response. The advection of the tropical anomaly up to the deep water for...

  17. Comparison of on Demand Routing Protocols

    Directory of Open Access Journals (Sweden)

    Bharat Bhushan

    2013-02-01

    Full Text Available A routing protocol is used to facilitate communication in ad hoc network. The primary goal of such a routing protocol is to provide an efficient and reliable path between a pair of nodes. The routing protocols for ad hoc network can be categorized into three categories: table driven, on demand and hybrid routing. The table driven and hybrid routing strategies require periodic exchange of hello messages between nodes of the ad hoc network and thus have high processing and bandwidth requirements. On the other hand on demand routing strategy creates routes when required and hence is very much suitable for ad hoc network. This paper therefore examines the performance of three on demand routing protocols at application layer using QualNet-5.01 simulator.

  18. The Pyramidal Capacitated Vehicle Routing Problem

    DEFF Research Database (Denmark)

    Lysgaard, Jens

    This paper introduces the Pyramidal Capacitated Vehicle Routing Problem (PCVRP) as a restricted version of the Capacitated Vehicle Routing Problem (CVRP). In the PCVRP each route is required to be pyramidal in a sense generalized from the Pyramidal Traveling Salesman Problem (PTSP). A pyramidal...... of a pyramidal route is such that its traversal can be divided in two parts, where on the first part of the route, customers are visited in nondecreasing distance from the depot, and on the remaining part of the route, customers are visited in nonincreasing distance from the depot. Such a route shape is indeed...... found in many optimal solutions to CVRP instances. An optimal solution to the PCVRP may therefore be useful in itself as a heuristic solution to the CVRP. Further, an attempt can be made to find an even better CVRP solution by solving a TSP, possibly leading to a non-pyramidal route, for each...

  19. Algorithmic generation of railroad and highway routes

    Energy Technology Data Exchange (ETDEWEB)

    Low, J. T.; Bushnell, R. C.; Shannon, R.; Borsos, R.; Graham, J.; Sherry, R.

    1979-01-01

    A minimum-time algorithm can be used to generate realistic highway routes between specific origins and destinations. Minimizing distances on links will not produce realistic railroad routes if links bear any resemblance to physical trackage. There are also multiple routes between two points since each carrier has its own philosophy. This paper outlines a systematic method of preparing information such that a computer algorithm can generate realistic routes for single- or multiple-carrier movements.

  20. Visual perception aspects of excursion route composition

    OpenAIRE

    Antonets, Margaryta

    2013-01-01

    Research dedicated to the influence of visual perception on landscape excursion routes composition should be based on the characteristics of human perception of the environment. During forming of excursion route an important part is design of visual frames as the primary compositional elements of visual impressions. The general visual impression of the route is characterized by two parameters: the level of attractiveness of objects and the level of attractiveness of route.

  1. VANET Routing Protocols: Pros and Cons

    OpenAIRE

    Paul, Bijan; Ibrahim, Md.; Bikas, Md. Abu Naser

    2012-01-01

    VANET (Vehicular Ad-hoc Network) is a new technology which has taken enormous attention in the recent years. Due to rapid topology changing and frequent disconnection makes it difficult to design an efficient routing protocol for routing data among vehicles, called V2V or vehicle to vehicle communication and vehicle to road side infrastructure, called V2I. The existing routing protocols for VANET are not efficient to meet every traffic scenarios. Thus design of an efficient routing protocol h...

  2. Routing Data Authentication in Wireless Networks; TOPICAL

    International Nuclear Information System (INIS)

    In this paper, we discuss several specific threats directed at the routing data of an ad hoc network. We address security issues that arise from wrapping authentication mechanisms around ad hoc routing data. We show that this bolt-on approach to security may make certain attacks more difficult, but still leaves the network routing data vulnerable. We also show that under a certain adversarial model, most existing routing protocols cannot be secured with the aid of digital signatures

  3. Blind Alley Aware ACO Routing Algorithm

    Science.gov (United States)

    Yoshikawa, Masaya; Otani, Kazuo

    2010-10-01

    The routing problem is applied to various engineering fields. Many researchers study this problem. In this paper, we propose a new routing algorithm which is based on Ant Colony Optimization. The proposed algorithm introduces the tabu search mechanism to escape the blind alley. Thus, the proposed algorithm enables to find the shortest route, even if the map data contains the blind alley. Experiments using map data prove the effectiveness in comparison with Dijkstra algorithm which is the most popular conventional routing algorithm.

  4. A route towards immune protection

    OpenAIRE

    Groot Nibbelink, Milou

    2016-01-01

    This work describes a route towards an immune protective device for islet of Langerhans transplantation. We developed a protocol to use MIN6 β cells aggregates as pseudo-islets to overcome the donor shortage issue (chapter 3). In this thesis we explored two different immune protective strategies; a multibore hollow fiber and flat microwell membranes. In chapter 4 we investigated the possibility to use a commercial multibore hollow fiber. In this chapter we showed that we were capable to physi...

  5. American Culture Reflected in American English

    Institute of Scientific and Technical Information of China (English)

    李华芳

    2013-01-01

    Language is a vehicle for culture. It is also a key component of culture. It not only reflects culture but also influences culture. As a variety of British English, American English, especially American words and expressions can reflect American culture from many aspects. This paper studies some typical traits of American culture reflected in words and expressions of American Eng-lish.

  6. Verkeersveiligheidseffecten van Dynamische Route Informatie Panelen (DRIP's).

    NARCIS (Netherlands)

    2008-01-01

    The term Dynamic Route Information Panel (DRIP) is, also in the Netherlands, used for an electronic route information panel. A DRIP usually indicates if there are queues on the various routes to a particular destination, how long they are, and sometimes what the estimated journey time is. This is in

  7. On line routing per mobile phone

    DEFF Research Database (Denmark)

    Bieding, Thomas; Görtz, Simon; Klose, Andreas

    2009-01-01

    On-line routing is concerned with building vehicle routes in an ongoing fashion in such a way that customer requests arriving dynamically in time are efficiently and effectively served. An indispensable prerequisite for applying on-line routing methods is mobile communication technology. Addition...

  8. Cultural Routes and Intangible Heritage

    Directory of Open Access Journals (Sweden)

    Enza Zabbini

    2012-08-01

    Full Text Available The theoretical interpretation of thematic routes helps to predict the effects on the territories visited by cultured tourists who want to enrich their cultural and emotional baggage. After the analysis of some interpretations, this paper will examine how the practical implementation of an itinerary approved by the Council of Europe has evolved over the years. And it will also reflect on the practical results in the areas involved in that project. "The Hannibal Pathway ", the main overland walk on the "Phoenician Route - Cultural Route recognized by the Council of Europe" – represents a case of study that allows to reflect over the impact of cultural tourism based on immaterial heritage. In fact, in the areas where the battle of 21 June 217 BC took place, nothing tangible is left, except the landscape that has kept its conformation intact. In these areas, thanks to the foresight of the local governments in the last three decades, the landscape of the plain has been preserved. This makes possible today to propose an historical path precisely based on the landscape and on the new techniques for the valorization of the heritage. In the Tuoro plain it is possible to see the battlefields, thus retracing the various stages of the battle, supported by the Documentation Centre of the Capra Palace and virtual reconstructions of high technical quality.

  9. Tricontinental Routes of Solidarity: Stokely Carmichael in Cuba

    Directory of Open Access Journals (Sweden)

    Sarah Seidman

    2012-12-01

    Full Text Available Stokely Carmichael’s visit to Cuba for three weeks in the summer of 1967 illustrates a convergence in the transnational routes of the African American freedom struggle and the Cuban Revolution. African American activists saw Cuba as a model for resisting US power, eradicating racism, and enacting societal change, while the Cuban government considered African Americans allies against US imperialism and advocates of Cuba’s antiracist stance. Amidst racial violence in the United States and Cuba’s efforts to inspire revolution, Carmichael’s presence at the Organization of Latin American Solidarity conference in Havana—and in particular his interactions with Fidel Castro—caused ripples worldwide. A shared “tricontinental” vision that promoted unity in the Global South against imperialism, capitalism, and racism facilitated Carmichael’s solidarity with Castro. Yet divergent views on the role of race in fighting oppression limited their solidarity. Carmichael and Castro’s spectacular alliance demonstrated their personal affinity and ideological commonalities but did not result in an institutional alliance between the black liberation movement and the Cuban state. Instead Carmichael’s connection with the Cuban Revolution left an underexplored legacy. Examining Carmichael’s visit to Cuba illustrates the possibilities and pitfalls of transnational solidarity and furthers our understanding of postwar struggles for change.

  10. Freshwater flux to Sermilik Fjord, SE Greenland

    Directory of Open Access Journals (Sweden)

    S. H. Mernild

    2010-07-01

    Full Text Available Fluctuations in terrestrial surface freshwater flux to Sermilik Fjord, SE Greenland, were simulated and analyzed. SnowModel, a state-of-the-art snow-evolution, snow and ice melt, and runoff modeling system, was used to simulate the temporal and spatial terrestrial runoff distribution to the fjord based on observed meteorological data (1999–2008 from stations located on and around the Greenland Ice Sheet (GrIS. Simulated runoff was compared and verified against independent glacier catchment runoff observations (1999–2005. Modeled runoff to Sermilik Fjord was highly variable, ranging from 2.9×109 m3 y−1 in 1999 to 5.9×109 m3 y−1 in 2005. The uneven spatial runoff distribution produced an areally-averaged annual maximum runoff at the Helheim glacier terminus of more than 3.8 m w.eq. The sub-catchment runoff of the Helheim glacier region accounted for 25% of the total runoff to Sermilik Fjord. The runoff distribution from the different sub-catchments suggested a strong influence from the spatial variation in glacier coverage. To assess the Sermilik Fjord freshwater flux, simulated terrestrial runoff and net precipitation (precipitation minus evaporation and sublimation for the fjord area were combined with satellite-derived ice discharge and subglacial geothermal and frictional melting due to basal ice motion. A terrestrial freshwater flux of ~40.4×109 m3 y−1 was found for Sermilik Fjord, with an 11% contribution originated from surface runoff. For the Helheim glacier sub-catchment only 4% of the flux originated from terrestrial surface runoff.

  11. Bird orientation at high latitudes: flight routes between Siberia and North America across the Arctic Ocean

    Science.gov (United States)

    Alerstam; Gudmundsson

    1999-12-22

    Bird migration and orientation at high latitudes are of special interest because of the difficulties associated with different compass systems in polar areas and because of the considerable differences between flight routes conforming to loxodromes (rhumblines) or orthodromes (great circle routes). Regular and widespread east-north-east migration of birds from the northern tundra of Siberia towards North America across the Arctic Ocean (without landmark influences) were recorded by ship-based tracking radar studies in July and August. Field observations indicated that waders, including species such as Phalaropusfulicarius and Calidris melanotos, dominated, but also terns and skuas may have been involved. Analysis of flight directions in relation to the wind showed that these movements are not caused by wind drift. Assuming possible orientation principles based on celestial or geomagnetic cues, different flight trajectories across the Arctic Ocean were calculated: geographical loxodromes, sun compass routes, magnetic loxodromes and magnetoclinic routes. The probabilities of these four alternatives are evaluated on the basis of both the availability of required orientation cues and the predicted flight paths. This evaluation supports orientation along sun compass routes. Because of the longitudinal time displacement sun compass routes show gradually changing compass courses in close agreement with orthodromes. It is suggested that an important migration link between Siberia and North American stopover sites 1000-2500km apart across the Arctic Ocean has evolved based on sun compass orientation along orthodrome-like routes. PMID:10693821

  12. Monitoring endangered freshwater biodiversity using environmental DNA

    DEFF Research Database (Denmark)

    Thomsen, Philip Francis; Kielgast, Jos; Iversen, Lars L.;

    2012-01-01

    that depend on practical and taxonomic expertise, which is rapidly declining. Here, we show that a diversity of rare and threatened freshwater animals-representing amphibians, fish, mammals, insects and crustaceans-can be detected and quantified based on DNA obtained directly from small water samples of lakes...... of amphibians and fish can be detected by high-throughput sequencing of DNA extracted from pond water. Our findings underpin the ubiquitous nature of DNA traces in the environment and establish environmental DNA as a tool for monitoring rare and threatened species across a wide range of taxonomic groups....

  13. Freshwater reservoir effect variability in Northern Germany

    DEFF Research Database (Denmark)

    Philippsen, B.; Heinemeier, J.

    2013-01-01

    The freshwater reservoir effect is a potential problem when radiocarbon dating fish bones, shells, human bones, or food crusts on pottery from sites near rivers or lakes. The reservoir age in hardwater rivers can be up to several thousand years and may be highly variable. Accurate 14C dating of f...... that can also be expected for the past. This knowledge will be applied to the dating of food crusts on pottery from the Mesolithic sites Kayhude at the Alster River and Schlamersdorf at the Trave River, both in Schleswig-Holstein, northern Germany....

  14. Real-time routing control design for traffic networks with multi-route choices

    Institute of Scientific and Technical Information of China (English)

    罗莉华; 葛颖恩; 陈继红; 张方伟

    2016-01-01

    This work considers those road networks in which there are multi-route choices for bifurcation-destination (or origin-destination) pairs, and designs a real-time variable message sign (VMS)-based routing control strategy in the model predictive control (MPC) framework. The VMS route recommendation provided by the traffic management authority is directly considered as the control variable, and the routing control model is established, in which a multi-dimensional control vector is introduced to describe the influence of route recommendations on flow distribution. In the MPC framework, a system optimum routing strategy with the constraints regarding drivers’ acceptability with recommended routes is designed, which can not only meet the traffic management authority’s control requirement but also improve drivers’ satisfaction with the route guidance system. The simulation carried out shows that the proposed routing control can effectively mitigate traffic congestion, reduces followers’ time delay, and improves drivers’ satisfaction with routing control in road networks.

  15. The pyramidal capacitated vehicle routing problem

    DEFF Research Database (Denmark)

    Lysgaard, Jens

    2010-01-01

    This paper introduces the pyramidal capacitated vehicle routing problem (PCVRP) as a restricted version of the capacitated vehicle routing problem (CVRP). In the PCVRP each route is required to be pyramidal in a sense generalized from the pyramidal traveling salesman problem (PTSP). A pyramidal....... A main feature of the algorithm is that exact pricing over elementary routes are done in pseudo-polynomial time. Computational results suggest that PCVRP solutions are highly useful for obtaining near-optimal solutions to the CVRP. Furthermore, pricing of pyramidal routes may prove to be very useful...

  16. Risk-minimal routes for emergency cars

    OpenAIRE

    Woelki, Marko; Nippold, Ronald; Bonert, Michael; Ruppe, Sten

    2013-01-01

    The computation of an optimal route for given start and destination in a static transportation network is used in many applications of private route planning. In this work we focus on route planning for emergency cars, such as for example police, fire brigade and ambulance. In case of private route planning typical quantities to be minimized are travel time or route length. However, the idea of this paper is to minimize the risk of a travel time exceeding a certain limit. This is inspired by ...

  17. Classification of Dynamic Vehicle Routing Systems

    DEFF Research Database (Denmark)

    Larsen, Allan; Madsen, Oli B.G.; Solomon, Marius M.

    2007-01-01

    to classify dynamic vehicle routing systems. Methods for evaluation of the performance of algorithms that solve on-line routing problems are discussed and we list some of the most important issues to include in the system objective. Finally, we provide a three-echelon classification of dynamic vehicle routing......This chapter discusses important characteristics seen within dynamic vehicle routing problems. We discuss the differences between the traditional static vehicle routing problems and its dynamic counterparts. We give an in-depth introduction to the degree of dynamism measure which can be used...

  18. Routing for wireless multi-hop networks

    CERN Document Server

    Hamid, Sherin Abdel; Takahara, Glen

    2013-01-01

    The focus of this brief is to identify what unifies and what distinguishes the routing functions in four wireless multi-hop network paradigms. The brief introduces a generic routing model that can be used as a foundation of wireless multi-hop routing protocol analysis and design. It demonstrates that such model can be adopted by any wireless multi-hop routing protocol. Also presented is a glimpse of the ideal wireless multi-hop routing protocol along with several open issues.

  19. Submarine Pipeline Routing Risk Quantitative Analysis

    Institute of Scientific and Technical Information of China (English)

    徐慧; 于莉; 胡云昌; 王金英

    2004-01-01

    A new method for submarine pipeline routing risk quantitative analysis was provided, and the study was developed from qualitative analysis to quantitative analysis.The characteristics of the potential risk of the submarine pipeline system were considered, and grey-mode identification theory was used. The study process was composed of three parts: establishing the indexes system of routing risk quantitative analysis, establishing the model of grey-mode identification for routing risk quantitative analysis, and establishing the standard of mode identification result. It is shown that this model can directly and concisely reflect the hazard degree of the routing through computing example, and prepares the routing selection for the future.

  20. American Houses

    Institute of Scientific and Technical Information of China (English)

    张梦华

    2004-01-01

    American houses usually have private kitchens,a living room and sometimes separate areas for eating and watching television,A house usually has its own mailbox,a yard with plants or perhaps a lawn,and a place to store garbage out of sight.

  1. American Occupation

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Angry Americans across the country are protesting against inequality, greed and corruption The "Occupy Wall Street" protests have grown from an insignificant lower Manhattan gathering of around 1,500 people to tens of thousands of people across the United States, from Anchorage,

  2. Toxoplasma gondii Infection in Seagull Chicks Is Related to the Consumption of Freshwater Food Resources

    Science.gov (United States)

    Cabezón, Oscar; Cerdà-Cuéllar, Marta; Morera, Virginia; García-Bocanegra, Ignacio; González-Solís, Jacob; Napp, Sebastian; Ribas, Maria P.; Blanch-Lázaro, Berta; Fernández-Aguilar, Xavier; Antilles, Noelia; López-Soria, Sergio; Lorca-Oró, Cristina; Dubey, Jitender P.; Almería, Sonia

    2016-01-01

    Understanding the spread of Toxoplasma gondii (T. gondii) in wild birds, particularly in those with opportunistic feeding behavior, is of interest for elucidating the epidemiological involvement of these birds in the maintenance and dissemination of the parasite. Overall, from 2009 to 2011, we collected sera from 525 seagull chicks (Yellow-legged gull (Larus michahellis) and Audouin’s gull (L. audouinii)) from 6 breeding colonies in Spain and tested them using the modified agglutination test (MAT) for the presence of antibodies against T. gondii. Chick age was estimated from bill length. Main food source of seagull chicks was evaluated using stable isotope analyses from growing scapular feathers. Overall T. gondii seroprevalence was 21.0% (IC95% 17.5–24.4). A generalized linear mixed-effects model indicated that year (2009) and food source (freshwater) were risk factors associated to the individual risk of infection by T. gondii, while age (days) was close to significance. Freshwater food origin was related to the highest seroprevalence levels, followed by marine origin, supporting freshwater and sewages as important routes of dispersion of T. gondii. Year differences could indicate fluctuating rates of exposure of seagull chicks to T. gondii. Age ranged from 4 to 30 days and seropositivity tended to increase with age (P = 0.07), supporting that seropositivity is related to T. gondii infection rather than to maternal transfer of antibodies, which in gulls is known to sharply decrease with chick age. This study is the first to report T. gondii antibodies in Yellow-legged and Audouin’s gulls, thereby extending the range of intermediate hosts for this parasite and underscoring the complexity of its epidemiology. PMID:26974667

  3. Toxoplasma gondii Infection in Seagull Chicks Is Related to the Consumption of Freshwater Food Resources.

    Science.gov (United States)

    Cabezón, Oscar; Cerdà-Cuéllar, Marta; Morera, Virginia; García-Bocanegra, Ignacio; González-Solís, Jacob; Napp, Sebastian; Ribas, Maria P; Blanch-Lázaro, Berta; Fernández-Aguilar, Xavier; Antilles, Noelia; López-Soria, Sergio; Lorca-Oró, Cristina; Dubey, Jitender P; Almería, Sonia

    2016-01-01

    Understanding the spread of Toxoplasma gondii (T. gondii) in wild birds, particularly in those with opportunistic feeding behavior, is of interest for elucidating the epidemiological involvement of these birds in the maintenance and dissemination of the parasite. Overall, from 2009 to 2011, we collected sera from 525 seagull chicks (Yellow-legged gull (Larus michahellis) and Audouin's gull (L. audouinii)) from 6 breeding colonies in Spain and tested them using the modified agglutination test (MAT) for the presence of antibodies against T. gondii. Chick age was estimated from bill length. Main food source of seagull chicks was evaluated using stable isotope analyses from growing scapular feathers. Overall T. gondii seroprevalence was 21.0% (IC95% 17.5-24.4). A generalized linear mixed-effects model indicated that year (2009) and food source (freshwater) were risk factors associated to the individual risk of infection by T. gondii, while age (days) was close to significance. Freshwater food origin was related to the highest seroprevalence levels, followed by marine origin, supporting freshwater and sewages as important routes of dispersion of T. gondii. Year differences could indicate fluctuating rates of exposure of seagull chicks to T. gondii. Age ranged from 4 to 30 days and seropositivity tended to increase with age (P = 0.07), supporting that seropositivity is related to T. gondii infection rather than to maternal transfer of antibodies, which in gulls is known to sharply decrease with chick age. This study is the first to report T. gondii antibodies in Yellow-legged and Audouin's gulls, thereby extending the range of intermediate hosts for this parasite and underscoring the complexity of its epidemiology. PMID:26974667

  4. VANET Routing Protocols: Pros and Cons

    CERN Document Server

    Paul, Bijan; Bikas, Md Abu Naser

    2012-01-01

    VANET (Vehicular Ad-hoc Network) is a new technology which has taken enormous attention in the recent years. Due to rapid topology changing and frequent disconnection makes it difficult to design an efficient routing protocol for routing data among vehicles, called V2V or vehicle to vehicle communication and vehicle to road side infrastructure, called V2I. The existing routing protocols for VANET are not efficient to meet every traffic scenarios. Thus design of an efficient routing protocol has taken significant attention. So, it is very necessary to identify the pros and cons of routing protocols which can be used for further improvement or development of any new routing protocol. This paper presents the pros and cons of VANET routing protocols for inter vehicle communication.

  5. MILITARY MULTI-HOP ROUTING PROTOCOL

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Military tactical network is one of the most important applications of ad hoc network. Currently the existing routing protocols are put forward based on the simple and universal network model which has the ability of multi-hop routing but cannot work efficiently in the special military applications. The narrow bandwidth and limited energy of the wireless network make general routing protocols seem to be more redundant.In order to satisfy military needs properly, this letter makes a detailed analysis of physical nodes and traffic distribution in military network, uses cross-layer design concept for reference, combines traffic characteristic of application layer with routing protocol design. It categorized routing problem as crucial routes and non-crucial routes which adopted separate maintenance methods. It not only realizes basic transmission function but also works efficiently. It is quite fit for military application.

  6. A Genetic Algorithm on Inventory Routing Problem

    Directory of Open Access Journals (Sweden)

    Nevin Aydın

    2014-03-01

    Full Text Available Inventory routing problem can be defined as forming the routes to serve to the retailers from the manufacturer, deciding on the quantity of the shipment to the retailers and deciding on the timing of the replenishments. The difference of inventory routing problems from vehicle routing problems is the consideration of the inventory positions of retailers and supplier, and making the decision accordingly. Inventory routing problems are complex in nature and they can be solved either theoretically or using a heuristics method. Metaheuristics is an emerging class of heuristics that can be applied to combinatorial optimization problems. In this paper, we provide the relationship between vendor-managed inventory and inventory routing problem. The proposed genetic for solving vehicle routing problem is described in detail.

  7. Dynamic information routing in complex networks

    Science.gov (United States)

    Kirst, Christoph; Timme, Marc; Battaglia, Demian

    2016-04-01

    Flexible information routing fundamentally underlies the function of many biological and artificial networks. Yet, how such systems may specifically communicate and dynamically route information is not well understood. Here we identify a generic mechanism to route information on top of collective dynamical reference states in complex networks. Switching between collective dynamics induces flexible reorganization of information sharing and routing patterns, as quantified by delayed mutual information and transfer entropy measures between activities of a network's units. We demonstrate the power of this mechanism specifically for oscillatory dynamics and analyse how individual unit properties, the network topology and external inputs co-act to systematically organize information routing. For multi-scale, modular architectures, we resolve routing patterns at all levels. Interestingly, local interventions within one sub-network may remotely determine nonlocal network-wide communication. These results help understanding and designing information routing patterns across systems where collective dynamics co-occurs with a communication function.

  8. Dynamic information routing in complex networks

    Science.gov (United States)

    Kirst, Christoph; Timme, Marc; Battaglia, Demian

    2016-01-01

    Flexible information routing fundamentally underlies the function of many biological and artificial networks. Yet, how such systems may specifically communicate and dynamically route information is not well understood. Here we identify a generic mechanism to route information on top of collective dynamical reference states in complex networks. Switching between collective dynamics induces flexible reorganization of information sharing and routing patterns, as quantified by delayed mutual information and transfer entropy measures between activities of a network's units. We demonstrate the power of this mechanism specifically for oscillatory dynamics and analyse how individual unit properties, the network topology and external inputs co-act to systematically organize information routing. For multi-scale, modular architectures, we resolve routing patterns at all levels. Interestingly, local interventions within one sub-network may remotely determine nonlocal network-wide communication. These results help understanding and designing information routing patterns across systems where collective dynamics co-occurs with a communication function. PMID:27067257

  9. Cancer and African Americans

    Science.gov (United States)

    ... Population Profiles > Black/African American > Cancer Cancer and African Americans African Americans have the highest mortality rate ... 65MB] At a glance – Top Cancer Sites for African Americans (2008-2012) Cancer Incidence Rates per 100, ...

  10. American Sign Language

    Science.gov (United States)

    ... Health Info » Voice, Speech, and Language American Sign Language On this page: What is American Sign Language? ... signs "I love you." What is American Sign Language? American Sign Language (ASL) is a complete, complex ...

  11. Freshwater fluxes through the Western Fram Strait

    Science.gov (United States)

    Meredith, Michael; Heywood, Karen; Dennis, Paul; Goldson, Laura; White, Rowan; Fahrbach, Eberhard; Schauer, Ursula; Østerhus, Svein

    Two hydrographic and δ18O transects across Fram Strait (Aug-Sept 1997, 1998) are used to examine freshwater contributions to the East Greenland Current (EGC). The EGC featured up to ˜16% meteoric water in both years, but was made comparatively more saline through the formation of up to ˜11 m of sea ice. We derive meteoric water fluxes of ˜3680 km³yr-1 in Aug-Sept 1997, and ˜2000 km³yr-1 in Aug-Sept 1998. The 1997 and 1998 data show a long-term mean sea ice flux through Fram Strait around half the long-term mean meteoric water flux. A 1991 δ18O section [Bauch et al., 1995] yielded a very similar ratio. Our 1998 section reveals fresh, low-δ18O water on the East Greenland shelf whose comparatively large volume constitutes a potentially significant contribution to the total freshwater flux through Fram Strait. Such fluxes are important to the regional and global thermohaline circulation; we suggest that efforts towards monitoring both the EGC and East Greenland shelf waters are thus required.

  12. Heart Rate Sensor for Freshwater Mussels

    Science.gov (United States)

    Just, C. L.; Vial, D. P.; Kruger, A.; Niemeier, J. J.; Lee, H. W.; Schroer, H. W.

    2014-12-01

    Researchers have long been interested the cardiac activity of mollusks. First, it is important as a basic measure of the animal's metabolism. Further, activities such as feeding and burrowing affect heart rate, as do environmental factors such as water salinity, water temperature, exposure, and predation. We have developed a small, noninvasive sensor for measuring freshwater mussel heart rate. Its working principle is as follows. An infrared (IR) light-emitting diode is placed in contact with the mussel shell. Some of the IR penetrates through the shell, reflects off internal organs, and traverses back. A photodetector detects this IR, and electronics condition the signal. The heartbeat of the animal modulates the IR, allowing one to measure the heart rate. The technique is widely-used in finger heart-rate monitors in humans. The sensors do not have to be positioned above the heart and several locations on the mussel shell work well. The sensor is small (8 mm × 10 mm) and consumes less than 1 mA, and has a simple one-wire interface that allows for easy integration into data acquisition hardware. We present heart rate measurements for the common pocketbook (lampsilis cardium) freshwater mussel.

  13. Research on Routing Protocol of Mobile Ad Hoc Network

    OpenAIRE

    Tuo Ming Fu; Che Min

    2016-01-01

    Routing protocol is an important content of mobile Ad Hoc. The typical mobile Ad Hoc network routing protocols is introduced. The advantages and disadvantages of these routing protocols are analyzed. A hybrid routing protocol is put forward based on this.

  14. 40 CFR 35.1605-2 - Freshwater lake.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Freshwater lake. 35.1605-2 Section 35.1605-2 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE... Lakes § 35.1605-2 Freshwater lake. Any inland pond, reservoir, impoundment, or other similar body...

  15. Recent changes in the freshwater composition east of Greenland

    NARCIS (Netherlands)

    de Steur, L.; Pickart, R.S.; Torres, D.J.; Valdimarsson, H.

    2015-01-01

    Results from three hydrographic surveys across the East Greenland Current between 2011 and 2013 are presented with focus on the freshwater sources. End-member analysis using salinity, d18O, and nutrient data shows that while meteoric water dominated the freshwater content, a significant amount of Pa

  16. Water rules all processes in tidal freshwater wetlands

    NARCIS (Netherlands)

    Barendregt, A.

    2012-01-01

    Three essential factors cause the presence of tidal freshwater wetlands (TFW). First, it is a freshwater ecosystem located in the upper part of the estuary, where permanent input of river water creates fresh conditions constantly. Second, there is a tidal pulse that causes very dynamic conditions in

  17. Potential Routes for Thermochemical Biorefineries

    OpenAIRE

    García Haro, Pedro; Ollero de Castro, Pedro Antonio; Vidal-Barrero, José Fernando; Villanueva Perales, Ángel Luis

    2013-01-01

    This critical review focuses on potential routes for the multi-production of chemicals and fuels in the framework of thermochemical biorefineries. The up-to-date research and development in this field has been limited to BTL/G (biomass-to-liquids/gases) studies, where biomass-derived synthesis gas (syngas) is converted into a single product with/without the co-production of electricity and heat. Simultaneously, the interest on biorefineries is growing but mostly refers to the biochemical proc...

  18. Improving Operational Acceptability of Dynamic Weather Routes Through Analysis of Commonly Use Routings

    Science.gov (United States)

    Evans, Antony D.; Sridhar, Banavar; McNally, David

    2016-01-01

    The Dynamic Weather Routes (DWR) tool is a ground-based trajectory automation system that continuously and automatically analyzes active in-flight aircraft in en route airspace to find simple modifications to flight plan routes that can save significant flying time, while avoiding weather and considering traffic conflicts, airspace sector congestion, special use airspace, and FAA routing restrictions. Trials of the DWR system have shown that significant delay savings are possible. However, some DWR advised routes are also rejected by dispatchers or modified before being accepted. Similarly, of those sent by dispatchers to flight crews as proposed route change requests, many are not accepted by air traffic control, or are modified before implementation as Center route amendments. Such actions suggest that the operational acceptability of DWR advised route corrections could be improved, which may reduce workload and increase delay savings. This paper analyzes the historical usage of different flight routings, varying from simple waypoint pairs to lengthy strings of waypoints incorporating jet routes, in order to improve DWR route acceptability. An approach is developed that can be incorporated into DWR, advising routings with high historical usage and savings potential similar to that of the nominal DWR advisory. It is hypothesized that modifying a nominal DWR routing to one that is commonly used, and nearby, will result in more actual savings since common routings are generally familiar and operationally acceptable to air traffic control. The approach allows routing segments with high historical usage to be concatenated to form routes that meet all DWR constraints. The relevance of a route's historical usage to its acceptance by dispatchers and air traffic control is quantified by analyzing historical DWR data. Results indicate that while historical usage may be less of a concern to flight dispatchers accepting or rejecting DWR advised route corrections, it may be

  19. Morphological alteration, lysosomal membrane fragility and apoptosis of the cells of Indian freshwater sponge exposed to washing soda (sodium carbonate).

    Science.gov (United States)

    Mukherjee, Soumalya; Ray, Mitali; Dutta, Manab Kumar; Acharya, Avanti; Mukhopadhyay, Sandip Kumar; Ray, Sajal

    2015-12-01

    Washing soda is chemically known as sodium carbonate and is a component of laundry detergent. Domestic effluent, drain water and various anthropogenic activities have been identified as major routes of sodium carbonate contamination of the freshwater ecosystem. The freshwater sponge, Eunapius carteri, bears ecological and evolutionary significance and is considered as a bioresource in aquatic ecosystems. The present study involves estimation of morphological damage, lysosomal membrane integrity, activity of phosphatases and apoptosis in the cells of E. carteri under the environmentally realistic concentrations of washing soda. Exposure to washing soda resulted in severe morphological alterations and damages in cells of E. carteri. Fragility and destabilization of lysosomal membranes of E. carteri under the sublethal exposure was indicative to toxin induced physiological stress in sponge. Prolonged exposure to sodium carbonate resulted a reduction in the activity of acid and alkaline phosphatases in the cells of E. carteri. Experimental concentration of 8 mg/l of washing soda for 192 h yielded an increase in the physiological level of cellular apoptosis among the semigranulocytes and granulocytes of E. carteri, which was suggestive to possible shift in apoptosis mediated immunoprotection. The results were indicative of an undesirable shift in the immune status of sponge. Contamination of the freshwater aquifers by washing soda thus poses an alarming ecotoxicological threat to sponges.

  20. Species diversity and distribution of freshwater crabs (Decapoda: Pseudothelphusidae inhabiting the basin of the Rio Grande de Térraba, Pacific slope of Costa Rica

    Directory of Open Access Journals (Sweden)

    Luis Rólier Lara

    2013-09-01

    Full Text Available During the last decades, knowledge on biodiversity of freshwater decapods has increased considerably; however, information about ecology of these crustaceans is scarce. Currently, the freshwater decapod fauna of Costa Rica is comprised by representatives of three families (Caridea: Palaemonidae and Atyidae; Brachyura: Pseudothelphusidae. The present study aims to describe the species diversity and distribution of freshwater crabs inhabiting the basin of the Rio Grande de Térraba, Pacific slope of Costa Rica, where the Instituto Costarricense de Electricidad (ICE plans to implement one of the largest damming projects in the region. Samples were collected in 39 locations at an altitude ranging from 20 to 1,225 m. Sampling was carried out during several months in 2007, 2009 and 2010. We collected a total of 661 crabs, comprising eight species of Pseudothelphusidae of three genera, representing 53% of the 15 pseudothelphusid crab species currently recorded from Costa Rica. The most common species was Ptychophallus paraxanthusi followed by P. tristani. Freshwater crabs were more frequently encountered in the middle-low region of the basin (between 311 and 600 m and less frequently in the medium-high basin (between 601 and 1,225 m. Ptychophallus paraxanthusi showed the widest distribution and was collected in altitudes ranging from 20 to 700 m. The Rio Grande de Térraba region can be considered as a relatively small, but highly diverse system. Therefore, any alteration of the basin of Rio Grande de Térraba, and especially the possible construction of a hydroelectric power plant, needs to be carefully analyzed to mitigate the damaging effects of this project on the freshwater crabs. More ecological information about freshwater crabs from Costa Rica and the Central American region are needed to reach a first reasonable overview on the ecological role of these decapods in freshwater systems.

  1. Energy Efficient Routing Protocol for MANET

    Directory of Open Access Journals (Sweden)

    S.Gopinath

    2012-03-01

    Full Text Available In recent years, many energy-efficient routing protocols have been proposed. However, very little efforts have been taken in studying the energy consumption of individual node, overhead and route maintaining issues. While not considering the design of energy efficient routing protocol, it may perform very worst than the normal routing protocol. Here, we have proposed On Demand Based Energy Efficient Routing Protocol (ODBEERP. The main aim of proposed protocol is to discover the minimum power-limitation route. The power limitation of a route is decided by the node which has the minimum energy in that route. So compared with the minimum node energy in any other route, the minimum node energy in the minimum power-limitation route has more energy. We have also proposed a more accurate analysis to track the energy consumptions due to various factors, and improve the performance during path discovery and in mobility scenarios. The proposed protocol is evaluated with object oriented discrete event simulator environment. Simulation results shows that the ODBEERP achieves good throughput, less delay, high packet delivery ratio and good energy efficiency than the existing protocol PEER.

  2. Bicretieria Optimization in Routing Games

    CERN Document Server

    Busch, Costas

    2008-01-01

    Two important metrics for measuring the quality of routing paths are the maximum edge congestion $C$ and maximum path length $D$. Here, we study bicriteria in routing games where each player $i$ selfishly selects a path that simultaneously minimizes its maximum edge congestion $C_i$ and path length $D_i$. We study the stability and price of anarchy of two bicriteria games: - {\\em Max games}, where the social cost is $\\max(C,D)$ and the player cost is $\\max(C_i, D_i)$. We prove that max games are stable and convergent under best-response dynamics, and that the price of anarchy is bounded above by the maximum path length in the players' strategy sets. We also show that this bound is tight in worst-case scenarios. - {\\em Sum games}, where the social cost is $C+D$ and the player cost is $C_i+D_i$. For sum games, we first show the negative result that there are game instances that have no Nash-equilibria. Therefore, we examine an approximate game called the {\\em sum-bucket game} that is always convergent (and ther...

  3. Identifying Canadian freshwater fishes through DNA barcodes.

    Directory of Open Access Journals (Sweden)

    Nicolas Hubert

    Full Text Available BACKGROUND: DNA barcoding aims to provide an efficient method for species-level identifications using an array of species specific molecular tags derived from the 5' region of the mitochondrial cytochrome c oxidase I (COI gene. The efficiency of the method hinges on the degree of sequence divergence among species and species-level identifications are relatively straightforward when the average genetic distance among individuals within a species does not exceed the average genetic distance between sister species. Fishes constitute a highly diverse group of vertebrates that exhibit deep phenotypic changes during development. In this context, the identification of fish species is challenging and DNA barcoding provide new perspectives in ecology and systematics of fishes. Here we examined the degree to which DNA barcoding discriminate freshwater fish species from the well-known Canadian fauna, which currently encompasses nearly 200 species, some which are of high economic value like salmons and sturgeons. METHODOLOGY/PRINCIPAL FINDINGS: We bi-directionally sequenced the standard 652 bp "barcode" region of COI for 1360 individuals belonging to 190 of the 203 Canadian freshwater fish species (95%. Most species were represented by multiple individuals (7.6 on average, the majority of which were retained as voucher specimens. The average genetic distance was 27 fold higher between species than within species, as K2P distance estimates averaged 8.3% among congeners and only 0.3% among concpecifics. However, shared polymorphism between sister-species was detected in 15 species (8% of the cases. The distribution of K2P distance between individuals and species overlapped and identifications were only possible to species group using DNA barcodes in these cases. Conversely, deep hidden genetic divergence was revealed within two species, suggesting the presence of cryptic species. CONCLUSIONS/SIGNIFICANCE: The present study evidenced that freshwater fish

  4. Gastric cryptosporidiosis in freshwater angelfish (Pterophyllum scalare).

    Science.gov (United States)

    Murphy, Brian G; Bradway, Daniel; Walsh, Timothy; Sanders, George E; Snekvik, Kevin

    2009-09-01

    A freshwater angelfish (Pterophyllum scalare) hatchery experienced variable levels of emaciation, poor growth rates, swollen coelomic cavities, anorexia, listlessness, and increased mortality within their fish. Multiple chemotherapeutic trials had been attempted without success. In affected fish, large numbers of protozoa were identified both histologically and ultrastructurally associated with the gastric mucosa. The youngest cohort of parasitized fish was the most severely affected and demonstrated the greatest morbidity and mortality. The protozoa were morphologically most consistent with Cryptosporidium. All of the protozoan life stages were identified ultrastructurally and protozoal genomic DNA was isolated from parasitized tissue viscera and sequenced. Histological, ultrastructural, genetic, and phylogenetic analyses confirmed this protozoal organism to be a novel species of Cryptosporidium. PMID:19737774

  5. Eutrophication of freshwater and marine ecosystems

    Science.gov (United States)

    Smith, Val H.; Joye, Samantha B.; Howarth, Robert W.

    2006-01-01

    Initial understanding of the links between nutrients and aquatic productivity originated in Europe in the early 1900s, and our knowledge base has expanded greatly during the past 40 yr. This explosion of eutrophication-related research has made it unequivocally clear that a comprehensive strategy to prevent excessive amounts of nitrogen and phosphorus from entering our waterways is needed to protect our lakes, rivers, and coasts from water quality deterioration. However, despite these very significant advances, cultural eutrophication remains one of the foremost problems for protecting our valuable surface water resources. The papers in this special issue provide a valuable cross section and synthesis of our current understanding of both freshwater and marine eutrophication science. They also serve to identify gaps in our knowledge and will help to guide future research.

  6. Toxicities of selected substances to freshwater biota

    Energy Technology Data Exchange (ETDEWEB)

    Hohreiter, D.W.

    1980-05-01

    The amount of data available concerning the toxicity of various substances to freshwater biota is so large that it is difficult to use in a practical situation, such as environmental impact assessment. In this document, summary tables are presented showing acute and/or chronic toxicity of selected substances for various groups of aquatic biota. Each entry is referenced to its original source so that details concerning experimental conditions may be consulted. In addition, general information concerning factors modifying toxicity, synergisms, evidence of bioaccumulation, and water quality standards and criteria for the selected substances is given. The final table is a general toxicity table designed to provide an easily accessible and general indication of toxicity of selected substances in aquatic systems.

  7. Freshwater snail consumption and angiostrongyliasis in Malaya.

    Science.gov (United States)

    Liat, L B; Fong, Y L; Krishnansamy, M; Ramachandran, P; Mansor, S

    1978-06-01

    A survey of the freshwater snails, Pila scutata and Bellamyia ingallsiana, as food consumed by the local population was carried out in Peninsular Malaysia. Of these two species the first is preferred; the sizes favoured are between 25--40 mm. Pila snails were found to be consumed by the three communities, viz. Malay, Chinese and Indian, in different ways. The various methods of preparing the snails for consumption are described. P. scutata is an intermediate host of the rat-lung worm, Angiostrongylus malaysiensis. As this worm presumably is the causative agent of human eosinophilic meningoencephalitis, the eating habits of the three races in consuming the snail in relation to the epidemiology of the disease was also discussed. PMID:726037

  8. Freshwater algae of the Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, W.D.; Giles, K.R.

    1979-06-01

    Fifty-two species of freshwater algae were identified in samples collected from the eight known natural springs of the Nevada Test Site. Although several species were widespread, 29 species were site specific. Diatoms provided the greatest variety of species at each spring. Three-fifths of all algal species encountered were diatoms. Well-developed mats of filamentous green algae (Chlorophyta) were common in many of the water tanks associated with the springs and accounted for most of the algal biomass. Major nutrients were adequate, if not abundant, in most spring waters - growth being limited primarily by light and physical habitat. There was some evidence of cesium-137 bioconcentration by algae at several of the springs.

  9. Vehicle routing problem in investment fund allocation

    Science.gov (United States)

    Mamat, Nur Jumaadzan Zaleha; Jaaman, Saiful Hafizah; Ahmad, Rokiah Rozita; Mohd, Ismail

    2013-04-01

    Since its introduction by Dantzig and Ramser in 1959, vehicle routing problem keeps evolving in theories, applications and variability. The evolution in computing and technology are also important contributors to research in solving vehicle routing problem. The main sectors of interests among researchers and practitioners for vehicle routing problem are transportation, distribution and logistics. However, literature found that concept and benefits of vehicle routing problem are not taken advantages of by researchers in the field of investment. Other methods found used in investment include multi-objective programming, linear programming, goal programming and integer programming. Yet the application of vehicle routing problem is not fully explored. A proposal on a framework of the fund allocation optimization using vehicle routing problem is presented here. Preliminary results using FTSE Bursa Malaysia data testing the framework are also given.

  10. Predicting transportation routes for radioactive wastes

    International Nuclear Information System (INIS)

    Oak Ridge National Laboratory (ORNL) has been involved in transportation logistics of radioactive wastes as part of the overall waste transportation program. A Spent Fuel Logistics Model (SFLM), was developed to predict overall material balances representing the flow of spent fuel assemblies from reactors to away-from-reactor storage facilities and/or to federal repositories. The transportation requirements to make these shipments are also itemized. The next logical step in the overall transportation project was the development of a set of computer codes which would predict likely transportation routes for waste shipments. Two separate routing models are now operational at ORNL. Routes for truck transport can be estimated with the HIGHWAY program, and rail and barge routes can be predicted with the INTERLINE model. This paper discusses examples of the route estimates and applications of the routing models

  11. Dynamic information routing in complex networks

    CERN Document Server

    Kirst, Christoph; Battaglia, Demian

    2015-01-01

    Flexible information routing fundamentally underlies the function of many biological and artificial networks. Yet, how such systems may specifically communicate and dynamically route information is not well understood. Here we identify a generic mechanism to route information on top of collective dynamical reference states in complex networks. Switching between collective dynamics induces flexible reorganization of information sharing and routing patterns, as quantified by delayed mutual information and transfer entropy measures between activities of a network's units. We demonstrate the power of this generic mechanism specifically for oscillatory dynamics and analyze how individual unit properties, the network topology and external inputs coact to systematically organize information routing. For multi-scale, modular architectures, we resolve routing patterns at all levels. Interestingly, local interventions within one sub-network may remotely determine non-local network-wide communication. These results help...

  12. Zone routing in a torus network

    Science.gov (United States)

    Chen, Dong; Heidelberger, Philip; Kumar, Sameer

    2013-01-29

    A system for routing data in a network comprising a network logic device at a sending node for determining a path between the sending node and a receiving node, wherein the network logic device sets one or more selection bits and one or more hint bits within the data packet, a control register for storing one or more masks, wherein the network logic device uses the one or more selection bits to select a mask from the control register and the network logic device applies the selected mask to the hint bits to restrict routing of the data packet to one or more routing directions for the data packet within the network and selects one of the restricted routing directions from the one or more routing directions and sends the data packet along a link in the selected routing direction toward the receiving node.

  13. On the glacial and interglacial thermohaline circulation and the associated transports of heat and freshwater

    Science.gov (United States)

    Ballarotta, M.; Falahat, S.; Brodeau, L.; Döös, K.

    2014-11-01

    The thermohaline circulation (THC) and the oceanic heat and freshwater transports are essential for understanding the global climate system. Streamfunctions are widely used in oceanography to represent the THC and estimate the transport of heat and freshwater. In the present study, the regional and global changes of the THC, the transports of heat and freshwater and the timescale of the circulation between the Last Glacial Maximum (LGM, ≈ 21 kyr ago) and the present-day climate are explored using an Ocean General Circulation Model and streamfunctions projected in various coordinate systems. We found that the LGM tropical circulation is about 10% stronger than under modern conditions due to stronger wind stress. Consequently, the maximum tropical transport of heat is about 20% larger during the LGM. In the North Atlantic basin, the large sea-ice extent during the LGM constrains the Gulf Stream to propagate in a more zonal direction, reducing the transport of heat towards high latitudes by almost 50% and reorganising the freshwater transport. The strength of the Atlantic Meridional Overturning Circulation depends strongly on the coordinate system. It varies between 9 and 16 Sv during the LGM, and between 12 to 19 Sv for the present day. Similar to paleo-proxy reconstructions, a large intrusion of saline Antarctic Bottom Water takes place into the Northern Hemisphere basins and squeezes most of the Conveyor Belt circulation into a shallower part of the ocean. These different haline regimes between the glacial and interglacial period are illustrated by the streamfunctions in latitude-salinity coordinates and thermohaline coordinates. From these diagnostics, we found that the LGM Conveyor Belt circulation is driven by an enhanced salinity contrast between the Atlantic and the Pacific basin. The LGM abyssal circulation lifts and makes the Conveyor Belt cell deviate from the abyssal region, resulting in a ventilated upper layer above a deep stagnant layer, and an

  14. Modified Rumor Routing for Wireless Sensor Networks

    OpenAIRE

    Chiranjib Patra; Parama Bhaumik; Debina Chakroborty

    2010-01-01

    Due to the limited processing power, and finite power available to each sensor node, regular ad-hoc routing techniques cannot be directly applied to sensor networks domain. Thus, energy-efficient routing algorithms suitable to the inherent characteristics of these types of networks are needed. However highly efficient data centric model of routing will improve the longevity of the network. This paper describes a mechanism of improvisation through simulation of existing feature of Rumor routin...

  15. Routing in Wireless Networks with Position Trees

    OpenAIRE

    Chavez, Edgar; Mitton, Nathalie; Tejeda, Hector

    2007-01-01

    Sensor networks are wireless adhoc networks where all the nodes cooperate for routing messages in the absence of a fixed infrastructure. Non-flooding, guaranteed delivery routing protocols are preferred because sensor networks have limited battery life. Location aware routing protocols are good candidates for sensor network applications, nevertheless they need either an external location service like GPS or Galileo (which are bulky, energy consuming devices) or internal location services prov...

  16. Martel's routes in Mammoth cave, Kentucky, 1912.

    OpenAIRE

    Shaw Trevor R.

    2003-01-01

    Martel’s own copy of the Hovey 1912 guidebook to Mammoth Cave has his routes marked faintly in pencil on the printed cave plans. These plans are reproduced here, with his routes indicated on them. He generally followed the four standard tourist routes which now included Kaemper’s 1908 discoveries to Violet City, but instead of visiting the Maelstrom he went to Hovey’s Cathedral and Gerta’s Grotto.

  17. Routing Protocols in MANET: Comparative Study

    OpenAIRE

    Jayanti; Vikram Nandal

    2014-01-01

    A Mobile Ad Hoc Network (MANET) is composed of mobile nodes without any infrastructure like wireless access points or base stations. MANET describes wireless, mobile and multi-hop networks that operate without the benefit of any existing infrastructure except for the nodes themselves. The main goal of an ad hoc network routing protocol is to establish correct and efficient route between a pair of mobile nodes so that messages delivered within the active route timeout interval. Several protoco...

  18. Gender differences in virtual route learning

    OpenAIRE

    Larios, Hector

    2011-01-01

    Past studies have found evidence of gender differences in route-learning strategies, indicating that men rely on configurational strategies (e.g., cardinal directions) and women rely on topographic strategies (e.g., landmarks). Whether and how these gender differences in route-learning strategies extend to virtual environments is not fully known. In this dissertation, I investigated gender differences in learning virtual routes from two frames of reference- egocentric and allocentric. One hun...

  19. Advances in optimal routing through computer networks

    Science.gov (United States)

    Paz, I. M.

    1977-01-01

    The optimal routing problem is defined. Progress in solving the problem during the previous decade is reviewed, with special emphasis on technical developments made during the last few years. The relationships between the routing, the throughput, and the switching technology used are discussed and their future trends are reviewed. Economic aspects are also briefly considered. Modern technical approaches for handling the routing problems and, more generally, the flow control problems are reviewed.

  20. Flood Routing Technique for Data Networks

    OpenAIRE

    Cho, Jaihyung; Breen, James

    1998-01-01

    In this paper, a new routing algorithm based on a flooding method is introduced. Flooding techniques have been used previously, e.g. for broadcasting the routing table in the ARPAnet [1] and other special purpose networks [3][4][5]. However, sending data using flooding can often saturate the network [2] and it is usually regarded as an inefficient broadcast mechanism. Our approach is to flood a very short packet to explore an optimal route without relying on a pre-established routing table, a...

  1. Performance of Conferencing over MANET Routing Protocols

    Directory of Open Access Journals (Sweden)

    Md. Ibrahim Abdullah

    2012-06-01

    Full Text Available Wireless ad hoc network represents a system of wireless nodes that can freely and dynamically self-organize into arbitrary and temporary network topologies, allowing people and devices to seamlessly internet-work in areas without any preexisting communication infrastructure. The routing protocols of this network elapsed much time in route discovery and route maintenances. In this research work we have studied the performance of routing protocols DSR and AODV when the nodes involved in video conferencing. Simulation studies show that AODV is better than DSR in coverage area with acceptable delay and packet loss.

  2. Biocatalytic Route to Surface Active Lipid

    DEFF Research Database (Denmark)

    Cheong, Ling-Zhi; Xu, Xuebing

    Lipid can be structurally modified in order to attain improved functional properties. This work look into the possibilities of developing surface active lipids with improved functional properties through biocatalytic route. Biocatalytic route to surface active lipid are usually complex involving...... a biphasic system as the substrates used may differs in polarity. In some instances, chemical synthetic route are used. Attempts are made to study the biocatalytic route to surface active lipid including various factors affecting synthesis of such compounds. The surface active lipids produced may have...

  3. American Houses

    Institute of Scientific and Technical Information of China (English)

    严双红

    2008-01-01

    <正>American houses usually have private kitchens,a living room and sometimes separate areas for eating and watching television.A house usually has its own mailbox,a yard with plants or perhaps a lawn,and a place to store garbage.美国住房通常有私人厨房,一间起居室,有时吃饭和看电视的地方是分开的。一所房子通常有自己的邮箱,一个种有植物或者有草坪的院子,还有存放垃圾的地方。

  4. "THE FISCAL FACTS: Public and Private Debts and the Future of the American Economy"

    OpenAIRE

    James K. Galbraith

    2006-01-01

    Today's federal budget deficits are a preoccupation of many American citizens and more than a few political leaders. Is the American government going bankrupt? Does our fiscal condition warrant radical surgery, as some now prescribe? Or, are we in such deep trouble that there is no plausible route of escape?

  5. Bus Routes, Marta Bus Routes located in Transportation database, Published in unknown, City of Roswell, GA.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Bus Routes dataset as of unknown. It is described as 'Marta Bus Routes located in Transportation database'. Data by this publisher are often provided in State...

  6. US Hazardous Materials Routes, Geographic WGS84, BTS (2006) [hazardous_material_routes_BTS_2006

    Data.gov (United States)

    Louisiana Geographic Information Center — The Federal Motor Carrier Safety Administration (FMCSA) Hazardous Material Routes were developed using the 2004 First Edition TIGER/Line files. The routes are...

  7. Network Resilience through Multiple Routing Configurations

    Directory of Open Access Journals (Sweden)

    Naga Raju Pamidi

    2011-11-01

    Full Text Available We propose the use of multi-topology (MT routing for network resilience against link and node failures. We describe the multi-topologies by an n-dimensional vector of different link costs for all links in the network. It is the base for the calculation of n shortest path trees from any node to all other destinations, i.e. for n virtual routing topologies. We define the link costs in such a way that the routing topologies complement each other in the sense that at least one valid route remains in a single link or node failure scenario for each pair of nodes in at least one routing topology. In such a failure case, packets are rather deviated over the intact routing topology than discarded. The recovery speed of the presented mechanism is very fast and can be compared to fast rerouting mechanisms in MPLS, which reduce packet, drops to a minimum. In contrast to MPLS, MT routing is still a pure IP-based solution that retains the scalability and the robustness of IP routing. As the Internet takes an increasingly central role in our communications infrastructure, the slow convergence of routing protocols after a network failure becomes a growing problem. To assure fast recovery from link and node failures in IP networks, we present a new recovery scheme called Multiple Routing Configurations (MRC. Our proposed scheme guarantees recovery in all single failure scenarios, using a single mechanism to handle both link and node failures, and without knowing the root cause of the failure. MRC is strictly connectionless, and assumes only destination based hop-by-hop forwarding. MRC is based on keeping additional routing information in the routers, and allows packet forwarding to continue on an alternative output link immediately after the detection of a failure. It can be implemented with only minor changes to existing solutions.

  8. FRESHWATER FISHERY OF THE REPUBLIC OF CROATIA

    Directory of Open Access Journals (Sweden)

    Zlatko Homen

    1999-09-01

    Full Text Available As fishery, including freshwater, is very important for economy of the Republic of Croatia, the aim of this paper is to show its condition from 1995 to 1998. and also to draw a plan for fish production in 1999. The period from 1998-1999. is more stressed in order to have a total and detailed view into the present condition of the freshwater fishery and into the direction in wish that production is going. Data about carp ponds and also about trout ponds is presented. Twentynine fish-ponds are processed out of which 20 are carp ponds and 9 trout ponds. Data was delivered to the Ministry of Agriculture and Forestry Fisheries Directorate. An assessment of the condition is made for 3 fish-ponds as the desired data was not provided. As to the number of employees on fish-ponds, a slight decline could be percived in the period from 1995 to 1997. In 1998 a number of employees considerably increased for 10.07% in relation to 1997. qualification of the employees in 1998. show that the most of them are unqualified what is in accord with the requirements of a job on a fish-pond. Overall surface of the carp ponds in 1998 was 12,708 and the production surface was 9,782 ha. The most of the fish-ponds have up to 500 ha of total surface (45.45%, while 50% of the fish-ponds have production surface from 500-100 ha. The production in the trout ponds is made on 165,905 m 2 of the overall surface of the ponds, and only 40,538 m 2 are the production surface of the ponds. The production of fish in that period was in constant increase and that increasing trend in expected in 1999, and it will be an 28.30 % increase in relation to 1998. The increase is expected for all kids of fish except for big head carps, silver carps and tinch fishs. As a part of the production of tinch fishs an increase in production of consumption tinch fish is expected, but a decrease in production of one-year and two-year old fishs and two-year old fish. Out of all kinds of fish, the most produced

  9. What Is the Best Route? Route-Finding Strategies of Middle School Students Using GIS

    Science.gov (United States)

    Wigglesivorth, John C.

    2003-01-01

    This paper summarizes a research project conducted to investigate the strategies developed by middle school students to solve a route-finding problem using Arc View GIS software. Three different types of route-finding strategies were identified. Some students were visual route-finders and used a highly visual strategy; others were logical route…

  10. New and previously described species of Dactylogyridae (Monogenoidea) from the gills of Panamanian freshwater fishes (Teleostei).

    Science.gov (United States)

    Mendoza-Franco, Edgar F; Aguirre-Macedo, M Leopoldina; Vidal-Martínez, Victor M

    2007-08-01

    During an investigation of the diversity of metazoan parasites of 7 freshwater fish species from 3 localities in central Panama, the following gill dactylogyrid (Monogenoidea) species were found: Aphanoblastella chagresii n. sp. from Pimelodella chagresi (Heptapteridae); Aphanoblastella travassosi (Price, 1938) Kritsky, Mendoza-Franco, and Scholz, 2000 from Rhamdia quelen (Heptapteridae); Diaphorocleidus petrosusi n. sp. from Brycon petrosus (Characidae); Gussevia asota Kritsky, Thatcher, and Boeger, 1989, from Astronotus ocellatus (Cichlidae); Sciadicleithrum panamensis n. sp. from Aequidens coeruleopunctatus (Cichlidae); Urocleidoides flegomai n. sp. from Piabucina panamensis (Lebiasinidae); and Urocleidoides similuncus n. sp. from Poecilia gillii (Poeciliidae). Consideration of the comparative morphology and distribution of these parasites along with the evolutionary history of the host fishes suggests that diversification may be associated with geotectonic events that provided isolation of the Central American fauna with the uplift of the Panamanian Isthmus during early Pliocene (3 mya). PMID:17918354

  11. Performance Evaluation of Routing Protocols in MANET

    Directory of Open Access Journals (Sweden)

    Smitha Sunny

    2015-01-01

    Full Text Available Mobile Ad-Hoc Network (MANET is an autonomous system that is composed of the mobile nodes which communicates through wireless links without any preexisting infrastructure. MANET is a collection of mobile nodes which can self-organize freely and dynamically into arbitrary and temporary network topologies. Mobile nodes in ad-hoc networks function as a router and can dynamically establish routes among themselves by means of a routing protocol. Routing protocols in mobile ad-hoc network helps node to send and receive packets. Therefore, selection of an appropriate routing protocol is an integral part of establishing a MANET. A suitable and effective routing mechanism helps to extend the successful deployment of mobile ad-hoc networks. An attempt has been made to compare the performance between on-demand reactive routing protocols namely AODV, DSR and proactive routing protocol namely DSDV for Constant Bit Rate (CBR traffic by varying network scope i.e. number of participating nodes as well as by varying the speed. The parameters used for evaluation are Packet delivery ratio (PDR, Normalized routing overhead, Average end to end delay (Delay, Throughput and Average Energy consumption. The simulations are carried out using Network Simulator NS2:34.

  12. TBRF: Trust Based Routing Framework for WSNs

    Directory of Open Access Journals (Sweden)

    Kushal Gulaskar

    2014-03-01

    Full Text Available The multi-hop routing in wireless sensor networks (WSNs offers little protection against identity deception through replaying routing information. An adversary can exploit this defect to launch various harmful or even devastating attacks against the routing protocols, including sinkhole attacks, wormhole attacks and Sybil attacks. The situation is further aggravated by mobile and harsh network conditions. Traditional cryptographic techniques or efforts at developing trust-aware routing protocols do not effectively address this severe problem. To secure the WSNs against adversaries misdirecting the multi-hop routing, we have designed and implemented TBRF, a robust trust-aware routing framework for dynamic WSNs. Without tight time synchronization or known geographic information, TBRF provides trustworthy and energy-efficient route. Most importantly, TBRF proves effective against those harmful attacks developed out of identity deception; the resilience of TBRF is verified through extensive evaluation with both simulation and empirical experiments on large-scale WSNs under various scenarios including mobile and RF-shielding network conditions. Further, we have implemented a low-overhead TBRF module in TinyOS; as demonstrated, this implementation can be incorporated into existing routing protocols with the least effort. Based on TBRF, we also demonstrated a proof-of-concept mobile target detection application that functions well against an anti-detection mechanism

  13. Using Collective Intelligence to Route Internet Traffic

    OpenAIRE

    DAVID H. WOLPERT; Tumer, Kagan; Frank, Jeremy

    1999-01-01

    A COllective INtelligence (COIN) is a set of interacting reinforcement learning (RL) algorithms designed in an automated fashion so that their collective behavior optimizes a global utility function. We summarize the theory of COINs, then present experiments using that theory to design COINs to control internet traffic routing. These experiments indicate that COINs outperform all previously investigated RL-based, shortest path routing algorithms.

  14. ROUTE CHOICE MODELLING FOR BICYCLE TRIPS

    Directory of Open Access Journals (Sweden)

    Ehsan Beheshtitabar

    2014-06-01

    Full Text Available This paper intends to find out which parameters have the highest influence on bicyclists’ route-choice-behaviour and how they contribute. There are many attributes considered throughout different studies that are favoured by cyclists. The attributes are the basis for generating a function which predicts the route choice of cyclists. The paper aims at making a comparison between distance-based routes and attribute-based routes. The model for creating the bicycle route choice program is based on the network model of Norrköping, Sweden. The preferred attributes of the model each assign a weight in the cost function of the model for each link of the urban network. The algorithm of the lowest cost function route searches the shortest path in terms of assigned link costs over the whole network. For comparing the results of the cost function and the shortest route (between an origin-destination, the model has a shortest path finding algorithm between different Origin and Destination pairs implemented. It has been viewed that around 25% of all cumulative routes do not show any distance differences between the shortest path distance and attributes based solution. With the used weights of the Standard scenario, it can be seen that the trade-off between shortest distance and safety respectively comfort can be optimized, fulfilling both criteria (distance and safety/comfort.

  15. Vessel Route Choice Theory and Modeling

    NARCIS (Netherlands)

    Shu, Y.; Daamen, W.; Ligteringen, H.; Hoogendoorn, S.P.

    2015-01-01

    A new maritime traffic model describes vessel traffic in ports and inland waterways better. In this research, vessel behavior is categorized into a tactical level (route choice) and an operational level (dynamics of vessel behavior). This new maritime traffic model comprises two parts. The route cho

  16. Environmental factors along the Northern Sea Route

    International Nuclear Information System (INIS)

    The Northern Sea Route runs ca 5,600 nautical miles across the top of Russia from Murmansk to Vladivostok, and includes half of the Arctic basin. An environmental impact assessment is needed for this route because of the potential for commercial shipping to disturb the vulnerable Arctic environment along the route. For example, Russian development of oil and gas resources in the area served by the route is expected to rise dramatically in the near future. Drilling in the route area offshore has already begun, and potential blowouts or tanker spills are of concern. A pilot study on the environment along this route was conducted in 1990/91, focusing on a study of the literature and communications with Russian scientists working on Arctic ecology. Existing data seem to be insufficient and generally only cover the westernmost and easternmost parts of the route. A five-year research plan is proposed to provide an inventory of Arctic species in the route area and levels of contaminants present, to assess the environmental sensitivity of the area, and analyze impacts that increased shipping might have on the environment. Protection measures will also be suggested. 1 fig

  17. Routing in Optical and Stochastic Networks

    NARCIS (Netherlands)

    Yang, S.

    2015-01-01

    In most types of networks (e.g., optical or transportation networks), finding one or more best paths from a source to a destination, is one of the biggest concerns of network users and providers. This process is known as routing. The routing problems differ accordingly depending on different applica

  18. Optimizing departure times in vehicle routes

    NARCIS (Netherlands)

    Kok, A.L.; Hans, E.W.; Schutten, J.M.J.

    2008-01-01

    Most solution methods for the vehicle routing problem with time windows (VRPTW) develop routes from the earliest feasible departure time. However, in practice, temporal traffic congestions make that such solutions are not optimal with respect to minimizing the total duty time. Furthermore, VRPTW sol

  19. Using Collective Intelligence to Route Internet Traffic

    Science.gov (United States)

    Wolpert, David H.; Tumer, Kagan; Frank, Jeremy

    1998-01-01

    A Collective Intelligence (COIN) is a community of interacting reinforcement learning (RL) algorithms designed so that their collective behavior maximizes a global utility function. We introduce the theory of COINs, then present experiments using that theory to design COINs to control internet traffic routing. These experiments indicate that COINs outperform previous RL-based systems for such routing that have previously been investigated.

  20. Secure Geographic Routing Protocols: Issues and Approaches

    CERN Document Server

    sookhak, Mehdi; Haghparast, Mahboobeh; ISnin, Ismail Fauzi

    2011-01-01

    In the years, routing protocols in wireless sensor networks (WSN) have been substantially investigated by researches. Most state-of-the-art surveys have focused on reviewing of wireless sensor network .In this paper we review the existing secure geographic routing protocols for wireless sensor network (WSN) and also provide a qualitative comparison of them.

  1. Joint Route Planning under Varying Market Conditions

    NARCIS (Netherlands)

    Cruijssen, F.C.A.M.; Braysy, O.; Dullaert, W.; Fleuren, H.A.; Salomon, M.

    2006-01-01

    Purpose - To provide empirical evidence on the level of savings that can be attained by joint route planning and how these savings depend on specific market characteristics.Design/methodology/approach - Joint route planning is a measure that companies can take to decrease the costs of their distribu

  2. Secure Geographic Routing Protocols: Issues and Approaches

    Directory of Open Access Journals (Sweden)

    Mehdi sookhak

    2011-09-01

    Full Text Available In the years, routing protocols in wireless sensor networks (WSN have been substantially investigated by researches Most state-of-the-art surveys have focused on reviewing of wireless sensor network .In this paper we review the existing secure geographic routing protocols for wireless sensor network (WSN and also provide a qualitative comparison of them.

  3. A new numerical benchmark of a freshwater lens

    Science.gov (United States)

    Stoeckl, L.; Walther, M.; Graf, T.

    2016-04-01

    A numerical benchmark for 2-D variable-density flow and solute transport in a freshwater lens is presented. The benchmark is based on results of laboratory experiments conducted by Stoeckl and Houben (2012) using a sand tank on the meter scale. This benchmark describes the formation and degradation of a freshwater lens over time as it can be found under real-world islands. An error analysis gave the appropriate spatial and temporal discretization of 1 mm and 8.64 s, respectively. The calibrated parameter set was obtained using the parameter estimation tool PEST. Comparing density-coupled and density-uncoupled results showed that the freshwater-saltwater interface position is strongly dependent on density differences. A benchmark that adequately represents saltwater intrusion and that includes realistic features of coastal aquifers or freshwater lenses was lacking. This new benchmark was thus developed and is demonstrated to be suitable to test variable-density groundwater models applied to saltwater intrusion investigations.

  4. Bibliography on cycling of trace metals in freshwater ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    LaRiviere, M.G.; Scott, A.J.; Woodfield, W.G.; Cushing, C.E.

    1978-07-01

    This bibliography is a listing of pertinent literature directly addressing the cycling of trace metals in freshwater ecosystems. Data on cycling, including the influences of environmental mediators, are included. 151 references.

  5. Bibliography on cycling of trace metals in freshwater ecosystems

    International Nuclear Information System (INIS)

    This bibliography is a listing of pertinent literature directly addressing the cycling of trace metals in freshwater ecosystems. Data on cycling, including the influences of environmental mediators, are included. 151 references

  6. Freshwater mussels of the Noxubee National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is a summary of the freshwater mussels on Noxubee National Wildlife Refuge. The species listed and assoicated informaiton is based on existing literature. The...

  7. Caernarvon freshwater diversion: Contaminants monitoring study (interim report)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Caernarvon Freshwater Diversion Structure was completed in January 1991 by the U.S. Army Corps of Engineers. The purpose of the structure is to divert...

  8. Freshwater mussels of North Mississippi National Wildlife Refuge Complex

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A literature search of the distribution of freshwater mussels anticipated to be found on refuges assoicated with the North Mississippi Refuges Cjomplex and museum...

  9. Determination of the most suitable oil pipeline route using GIS least cost path analysis

    OpenAIRE

    Huseynli, Shahin

    2015-01-01

    The Keystone XL has a big role for transforming Canadian oil to the USA. The function of the pipeline is decreasing the dependency of the American oil industry on other countries and it will help to limit external debt. The proposed pipeline seeks the most suitable route which cannot damage agricultural and natural water recourses such as the Ogallala Aquifer. Using the Geographic Information System (GIS) techniques, the suggested path in this study got extremely high correct results that ...

  10. Land-Grant Colleges and American Engineers: Redefining Professional and Vocational Engineering Education in the American Midwest, 1862-1917

    Science.gov (United States)

    Nienkamp, Paul

    2010-01-01

    During the twentieth-century, American engineers harnessed the atom, sent men to the moon, and literally reshaped the world. They re-routed rivers to create giant hydroelectric dams, created a massive and interconnected highway system, and designed skyscrapers, jets, computers, and the internet. As a modern profession, engineering boasted strong…

  11. Caspian producers contemplate excess of export routes

    International Nuclear Information System (INIS)

    The fourth quarter of 2005 sees the commissioning of the latest oil export route from the Caspian: the Baku-Tbilisi-Ceyhan (BTC) pipeline from Azerbaijan to Turkey. BTC is one of a series of potential export routes from Central Asia and the Trans-Caucasus. The proposed capacity of all these routes, however, far exceeds the volume of oil likely to be available to fill it at any time in the foreseeable future. Turkey nevertheless continues to press for more export capacity in an attempt to reduce the number of tankers passing through the narrow waterways that connect the Black Sea with the Mediterranean. For their part, Caspian oil producers want their oil to be transported by the cheapest and most direct route, which appears to rule out pipelines designed to divert their exports away from the Black Sea-Mediterranean sea-route. (author)

  12. Individuality in bird migration: routes and timing.

    Science.gov (United States)

    Vardanis, Yannis; Klaassen, Raymond H G; Strandberg, Roine; Alerstam, Thomas

    2011-08-23

    The exploration of animal migration has entered a new era with individual-based tracking during multiple years. Here, we investigated repeated migratory journeys of a long-distance migrating bird, the marsh harrier Circus aeruginosus, in order to analyse the variation within and between individuals with respect to routes and timing. We found that there was a stronger individual repeatability in time than in space. Thus, the annual timing of migration varied much less between repeated journeys of the same individual than between different individuals, while there was considerable variation in the routes of the same individual on repeated journeys. The overall contrast in repeatability between time and space was unexpected and may be owing to strong endogenous control of timing, while short-term variation in environmental conditions (weather and habitat) might promote route flexibility. The individual variation in migration routes indicates that the birds navigate mainly by other means than detailed route recapitulation based on landmark recognition.

  13. Highway and interline transportation routing models

    International Nuclear Information System (INIS)

    The potential impacts associated with the transportation of hazardous materials are important issues to shippers, carriers, and the general public. Since transportation routes are a central characteristic in most of these issues, the prediction of likely routes is the first step toward the resolution of these issues. In addition, US Department of Transportation requirements (HM-164) mandate specific routes for shipments of highway controlled quantities of radioactive materials. In response to these needs, two routing models have been developed at Oak Ridge National Laboratory under the sponsorship of the U.S. Department of Energy (DOE). These models have been designated by DOE's Office of Environmental Restoration and Waste Management, Transportation Management Division (DOE/EM) as the official DOE routing models. Both models, HIGHWAY and INTERLINE, are described

  14. Routing architecture and security for airborne networks

    Science.gov (United States)

    Deng, Hongmei; Xie, Peng; Li, Jason; Xu, Roger; Levy, Renato

    2009-05-01

    Airborne networks are envisioned to provide interconnectivity for terrestial and space networks by interconnecting highly mobile airborne platforms. A number of military applications are expected to be used by the operator, and all these applications require proper routing security support to establish correct route between communicating platforms in a timely manner. As airborne networks somewhat different from traditional wired and wireless networks (e.g., Internet, LAN, WLAN, MANET, etc), security aspects valid in these networks are not fully applicable to airborne networks. Designing an efficient security scheme to protect airborne networks is confronted with new requirements. In this paper, we first identify a candidate routing architecture, which works as an underlying structure for our proposed security scheme. And then we investigate the vulnerabilities and attack models against routing protocols in airborne networks. Based on these studies, we propose an integrated security solution to address routing security issues in airborne networks.

  15. Individuality in bird migration: routes and timing.

    Science.gov (United States)

    Vardanis, Yannis; Klaassen, Raymond H G; Strandberg, Roine; Alerstam, Thomas

    2011-08-23

    The exploration of animal migration has entered a new era with individual-based tracking during multiple years. Here, we investigated repeated migratory journeys of a long-distance migrating bird, the marsh harrier Circus aeruginosus, in order to analyse the variation within and between individuals with respect to routes and timing. We found that there was a stronger individual repeatability in time than in space. Thus, the annual timing of migration varied much less between repeated journeys of the same individual than between different individuals, while there was considerable variation in the routes of the same individual on repeated journeys. The overall contrast in repeatability between time and space was unexpected and may be owing to strong endogenous control of timing, while short-term variation in environmental conditions (weather and habitat) might promote route flexibility. The individual variation in migration routes indicates that the birds navigate mainly by other means than detailed route recapitulation based on landmark recognition. PMID:21307045

  16. Freshwater aquaculture in the United States: Complying with environmental protection law and policy

    OpenAIRE

    Noble, M.

    1993-01-01

    The author deal with the relations between the freshwater fish culture and the many regulations of the environmental protection in USA. The author develops the federal and state administrative frameworks (federal government administration of aquaculture, the state government administration of aquaculture), the freshwater aquaculture and water rights, the freshwater aquaculture and wetlands regulation, the freshwater aquaculture and water quality regulation, the freshwater aquaculture and wild...

  17. The evolution of reproductive isolation in a simultaneous hermaphrodite, the freshwater snail Physa

    Directory of Open Access Journals (Sweden)

    Lydeard Charles

    2011-05-01

    Full Text Available Abstract Background The cosmopolitan freshwater snail Physa acuta has recently found widespread use as a model organism for the study of mating systems and reproductive allocation. Mitochondrial DNA phylogenies suggest that Physa carolinae, recently described from the American southeast, is a sister species of P. acuta. The divergence of the acuta/carolinae ancestor from the more widespread P. pomilia appears to be somewhat older, and the split between a hypothetical acuta/carolinae/pomilia ancestor and P. gyrina appears older still. Results Here we report the results of no-choice mating experiments yielding no evidence of hybridization between gyrina and any of four other populations (pomilia, carolinae, Philadelphia acuta, or Charleston acuta, nor between pomilia and carolinae. Crosses between pomilia and both acuta populations yielded sterile F1 progeny with reduced viability, while crosses between carolinae and both acuta populations yielded sterile F1 hybrids of normal viability. A set of mate-choice tests also revealed significant sexual isolation between gyrina and all four of our other Physa populations, between pomilia and carolinae, and between pomilia and Charleston acuta, but not between pomilia and the acuta population from Philadelphia, nor between carolinae and either acuta population. These observations are consistent with the origin of hybrid sterility prior to hybrid inviability, and a hypothesis that speciation between pomilia and acuta may have been reinforced by selection for prezygotic reproductive isolation in sympatry. Conclusions We propose a two-factor model for the evolution of postzygotic reproductive incompatibility in this set of five Physa populations consistent with the Dobzhansky-Muller model of speciation, and a second two-factor model for the evolution of sexual incompatibility. Under these models, species trees may be said to correspond with gene trees in American populations of the freshwater snail, Physa.

  18. SILENT WITNESS OF WATER POLLUTION: BIOINDICATOR FRESHWATER INVERTEBRATES

    OpenAIRE

    ARSLAN, Naime; Kara, Deniz; ODABAŞI, Deniz Anıl

    2015-01-01

    During the last years, not only industrial activities, but also anthropogenic activities have had negative consequences for the freshwater ecosystems. All aquatic organisms accumulate organic or inorganic elements in their bodies whether or not these elements are essential to metabolism. Community compositions of freshwater invertebrates such as gastropods, oligochaetes and chironomids, reflect the states and changes in aquatic ecosystems. Many factors regulate the occurrence and distribution...

  19. Nucleus Pearl Coating Process of Freshwater Mussel Anodonta woodiana (Unionidae)

    OpenAIRE

    WASMEN MANALU; DEDY DURYADI SOLIHIN; SATA YOSHIDA SRIE RAHAYU; RIDWAN AFFANDI

    2013-01-01

    The limiting factor which is a weakness of sea water pearl production are high costs, the risk of major business failures and a long coating time. From the issue of freshwater pearls appear to have prospects of alternative substitution for sea water pearl. This present study aimed to evaluate effect of loads (the number and diameter nucleus) on freshwater pearl coating process and the number and size of the appropriate nucleus diameter, to produce the optimum coating thickness of half-round p...

  20. Richness and endemism of the freshwater fishes of Mexico

    OpenAIRE

    T. Contreras-MacBeath; M. B. Rodríguez; Sorani, V.; Goldspink, C.; G. McGregor Reid

    2014-01-01

    A study of richness and endemism of the freshwater fishes of Mexico, was carried out in order to identify hotspots and inform conservation efforts. This was done by mapping and overlaying individual species distributions by means of geographical information systems based on museum data. The study was able to confirm several previously proposed centres of freshwater fish richness (Southeastern Mexico, the Mesa Central, the Bravo-Conchos river system and the Panuco and Tuxpan-Nautla rivers). Se...

  1. Restricted-range fishes and the conservation of Brazilian freshwaters.

    Directory of Open Access Journals (Sweden)

    Cristiano Nogueira

    Full Text Available BACKGROUND: Freshwaters are the most threatened ecosystems on earth. Although recent assessments provide data on global priority regions for freshwater conservation, local scale priorities remain unknown. Refining the scale of global biodiversity assessments (both at terrestrial and freshwater realms and translating these into conservation priorities on the ground remains a major challenge to biodiversity science, and depends directly on species occurrence data of high taxonomic and geographic resolution. Brazil harbors the richest freshwater ichthyofauna in the world, but knowledge on endemic areas and conservation in Brazilian rivers is still scarce. METHODOLOGY/PRINCIPAL FINDINGS: Using data on environmental threats and revised species distribution data we detect and delineate 540 small watershed areas harboring 819 restricted-range fishes in Brazil. Many of these areas are already highly threatened, as 159 (29% watersheds have lost more than 70% of their original vegetation cover, and only 141 (26% show significant overlap with formally protected areas or indigenous lands. We detected 220 (40% critical watersheds overlapping hydroelectric dams or showing both poor formal protection and widespread habitat loss; these sites harbor 344 endemic fish species that may face extinction if no conservation action is in place in the near future. CONCLUSIONS/SIGNIFICANCE: We provide the first analysis of site-scale conservation priorities in the richest freshwater ecosystems of the globe. Our results corroborate the hypothesis that freshwater biodiversity has been neglected in former conservation assessments. The study provides a simple and straightforward method for detecting freshwater priority areas based on endemism and threat, and represents a starting point for integrating freshwater and terrestrial conservation in representative and biogeographically consistent site-scale conservation strategies, that may be scaled-up following naturally linked

  2. UAV-based hyperspectral monitoring of small freshwater area

    Science.gov (United States)

    Pölönen, I.; Puupponen, H.-H.; Honkavaara, Eija; Lindfors, A.; Saari, H.; Markelin, L.; Hakala, T.; Nurminen, K.

    2014-10-01

    Recent development in compact, lightweight hyperspectral imagers have enabled UAV-based remote sensing with reasonable costs. We used small hyperspectral imager based on Fabry-Perot interferometer for monitoring small freshwater area in southern Finland. In this study we shortly describe the utilized technology and the field studies performed. We explain processing pipeline for gathered spectral data and introduce target detection-based algorithm for estimating levels of algae, aquatic chlorophyll and turbidity in freshwater. Certain challenges we faced are pointed out.

  3. New data on freshwater psammic Gastrotricha from Brazil

    OpenAIRE

    André Rinaldo Garraffoni; Thiago Araujo; Anete Lourenço; Maria Balsamo

    2010-01-01

    Current knowledge of freshwater gastrotrich fauna from Brazil is underestimated as only two studies are available. The present communication is a taxonomic account of the first-ever survey of freshwater Gastrotricha in Minas Gerais State. Samplings were carried out yielding six species of three Chaetonotidae genera: Aspidiophorus cf. pleustonicus, Ichthydium cf. chaetiferum, Chaetonotus acanthocephalus, C. heideri, C. cf. succinctus, Chaetonotus sp., and also an undescribed species belonging ...

  4. New data on freshwater psammic Gastrotricha from Brazil

    OpenAIRE

    André R. S. Garraffoni; Araujo, Thiago Q.; Lourenço, Anete P.; Balsamo, Maria

    2010-01-01

    Abstract Current knowledge of freshwater gastrotrich fauna from Brazil is underestimated as only two studies are available. The present communication is a taxonomic account of the first-ever survey of freshwater Gastrotricha in Minas Gerais State. Samplings were carried out yielding six species of three Chaetonotidae genera: Aspidiophorus cf. pleustonicus, Ichthydium cf. chaetiferum, Chaetonotus acanthocephalus, Chaetonotus heideri, Chaetonotus cf. succinctus, Chaetonotus sp., and also an und...

  5. Cyanobacterial biodiversity from different freshwater ponds of Thanjavur, Tamilnadu (India)

    OpenAIRE

    Muthukumar, Chinnasamy; Muralitharan, Gangatharan; Vijayakumar, Ramasamy; Panneerselvam, Annamalai; Thajuddin, Nooruddin

    2007-01-01

    Cyanobacterial biodiversity from different freshwater ponds of Thanjavur, Tamilnadu (India). Studies on the cyanobacterial biodiversity of 5 different freshwater ponds in and around Thanjavur, Tamilnadu during summer month (June, 2004) has been made and compared their variations among five different ponds. In addition, certain physico-chemical parameters of pond waters such as dissolved oxygen, net productivity, pH, carbonate, bicarbonate, nitrate, nitrite, total phosphorus, inorganic phospho...

  6. Water rules all processes in tidal freshwater wetlands

    OpenAIRE

    Barendregt, A.

    2012-01-01

    Three essential factors cause the presence of tidal freshwater wetlands (TFW). First, it is a freshwater ecosystem located in the upper part of the estuary, where permanent input of river water creates fresh conditions constantly. Second, there is a tidal pulse that causes very dynamic conditions in current, flooding, redistribution of sediments and morphology. Moreover, it is a wetland with permanently reduced condition in the soil. Third, because the river is the sink of the uplands, this e...

  7. Obesity and African Americans

    Science.gov (United States)

    ... Data > Minority Population Profiles > Black/African American > Obesity Obesity and African Americans African American women have the ... ss6304.pdf [PDF | 3.38MB] HEALTH IMPACT OF OBESITY More than 80 percent of people with type ...

  8. Border Collision Route to Quasiperiodicity: Numerical Investigation and Experimental Confirmation

    DEFF Research Database (Denmark)

    Zhusubaliyev, Zhanybai; Mosekilde, Erik; Maity, S.;

    2006-01-01

    Numerical studies of higher-dimensional piecewise-smooth systems have recently shown how a torus can arise from a periodic cycle through a special type of border-collision bifurcation. The present article investigates this new route to quasiperiodicity in the two-dimensional piecewise-linear normal...... periodicity, e.g., a period-5 focus. This article also contains a discussion of torus destruction via a homoclinic bifurcation in the piecewise-linear normal map. Using a dc–dc converter with two-level control as an example, we report the first experimental verification of the direct transition...... to quasiperiodicity through a border-collision bifurcation. ©2006 American Institute of Physics...

  9. Stormwater runoff drives viral community composition changes in inland freshwaters

    Directory of Open Access Journals (Sweden)

    Kurt E. Williamson

    2014-03-01

    Full Text Available Storm events impact freshwater microbial communities by transporting terrestrial viruses and other microbes to freshwater systems, and by potentially resuspending microbes from bottom sediments. The magnitude of these impacts on freshwater ecosystems is unknown and largely unexplored. Field studies carried out at two discrete sites in coastal Virginia (USA were used to characterize the viral load carried by runoff and to test the hypothesis that terrestrial viruses introduced through stormwater runoff change the composition of freshwater microbial communities. Field data gathered from an agricultural watershed indicated that primary runoff can contain viral densities approximating those of receiving waters. Furthermore, viruses attached to suspended colloids made up a large fraction of the total load, particularly in early stages of the storm. At a second field site (stormwater retention pond, RAPD-PCR profiling showed that the viral community of the pond changed dramatically over the course of two intense storms while relatively little change was observed over similar time scales in the absence of disturbance. Comparisons of planktonic and particle-associated viral communities revealed two completely distinct communities, suggesting that particle-associated viruses represent a potentially large and overlooked portion of aquatic viral abundance and diversity. Our findings show that stormwater runoff can quickly change the composition of freshwater microbial communities. Based on these findings, increased storms in the coastal mid-Atlantic region predicted by most climate change models will likely have important impacts on the structure and function of local freshwater microbial communities.

  10. Deep-ocean origin of the freshwater eels.

    Science.gov (United States)

    Inoue, Jun G; Miya, Masaki; Miller, Michael J; Sado, Tetsuya; Hanel, Reinhold; Hatooka, Kiyotaka; Aoyama, Jun; Minegishi, Yuki; Nishida, Mutsumi; Tsukamoto, Katsumi

    2010-06-23

    Of more than 800 species of eels of the order Anguilliformes, only freshwater eels (genus Anguilla with 16 species plus three subspecies) spend most of their lives in freshwater during their catadromous life cycle. Nevertheless, because their spawning areas are located offshore in the open ocean, they migrate back to their specific breeding places in the ocean, often located thousands of kilometres away. The evolutionary origin of such enigmatic behaviour, however, remains elusive because of the uncertain phylogenetic position of freshwater eels within the principally marine anguilliforms. Here, we show strong evidence for a deep oceanic origin of the freshwater eels, based on the phylogenetic analysis of whole mitochondrial genome sequences from 56 species representing all of the 19 anguilliform families. The freshwater eels occupy an apical position within the anguilliforms, forming a highly supported monophyletic group with various oceanic midwater eel species. Moreover, reconstruction of the growth habitats on the resulting tree unequivocally indicates an origination of the freshwater eels from the midwater of the deep ocean. This shows significant concordance with the recent collection of mature adults of the Japanese eel in the upper midwater of the Pacific, suggesting that they have retained their evolutionary origin as a behavioural trait in their spawning areas. PMID:20053660

  11. New routes for allergen immunotherapy.

    Science.gov (United States)

    Johansen, Pål; von Moos, Seraina; Mohanan, Deepa; Kündig, Thomas M; Senti, Gabriela

    2012-10-01

    IgE-mediated allergy is a highly prevalent disease in the industrialized world. Allergen-specific immunotherapy (SIT) should be the preferred treatment, as it has long lasting protective effects and can stop the progression of the disease. However, few allergic patients choose to undergo SIT, due to the long treatment time and potential allergic adverse events. Since the beneficial effects of SIT are mediated by antigen presenting cells inducing Th1, Treg and antibody responses, whereas the adverse events are caused by mast cells and basophils, the therapeutic window of SIT may be widened by targeting tissues rich in antigen presenting cells. Lymph nodes and the epidermis contain high density of dendritic cells and low numbers of mast cells and basophils. The epidermis has the added benefit of not being vascularised thereby reducing the chances of anaphylactic shock due to leakage of allergen. Hence, both these tissues represent highly promising routes for SIT and are the focus of discussion in this review. PMID:23095873

  12. Drug targeting through pilosebaceous route.

    Science.gov (United States)

    Chourasia, Rashmi; Jain, Sanjay K

    2009-10-01

    Local skin targeting is of interest for the pharmaceutical and the cosmetic industry. A topically applied substance has basically three possibilities to penetrate into the skin: transcellular, intercellular, and follicular. The transfollicular path has been largely ignored because hair follicles constitute only 0.1% of the total skin. The hair follicle is a skin appendage with a complex structure containing many cell types that produce highly specialised proteins. The hair follicle is in a continuous cycle: anagen is the hair growth phase, catagen the involution phase and telogen is the resting phase. Nonetheless, the hair follicle has great potential for skin treatment, owing to its deep extension into the dermis and thus provides much deeper penetration and absorption of compounds beneath the skin than seen with the transdermal route. In the case of skin diseases and of cosmetic products, delivery to sweat glands or to the pilosebaceous unit is essential for the effectiveness of the drug. Increased accumulation in the pilosebaceous unit could treat alopecia, acne and skin cancer more efficiently and improve the effect of cosmetic substances and nutrients. Therefore, we review herein various drug delivery systems, including liposomes, niosomes, microspheres, nanoparticles, nanoemulsions, lipid nanocarriers, gene therapy and discuss the results of recent researches. We also review the drugs which have been investigated for pilosebaceous delivery.

  13. Drug targeting through pilosebaceous route.

    Science.gov (United States)

    Chourasia, Rashmi; Jain, Sanjay K

    2009-10-01

    Local skin targeting is of interest for the pharmaceutical and the cosmetic industry. A topically applied substance has basically three possibilities to penetrate into the skin: transcellular, intercellular, and follicular. The transfollicular path has been largely ignored because hair follicles constitute only 0.1% of the total skin. The hair follicle is a skin appendage with a complex structure containing many cell types that produce highly specialised proteins. The hair follicle is in a continuous cycle: anagen is the hair growth phase, catagen the involution phase and telogen is the resting phase. Nonetheless, the hair follicle has great potential for skin treatment, owing to its deep extension into the dermis and thus provides much deeper penetration and absorption of compounds beneath the skin than seen with the transdermal route. In the case of skin diseases and of cosmetic products, delivery to sweat glands or to the pilosebaceous unit is essential for the effectiveness of the drug. Increased accumulation in the pilosebaceous unit could treat alopecia, acne and skin cancer more efficiently and improve the effect of cosmetic substances and nutrients. Therefore, we review herein various drug delivery systems, including liposomes, niosomes, microspheres, nanoparticles, nanoemulsions, lipid nanocarriers, gene therapy and discuss the results of recent researches. We also review the drugs which have been investigated for pilosebaceous delivery. PMID:19663765

  14. Bioaccumulation factors for radionuclides in freshwater biota

    International Nuclear Information System (INIS)

    This report analyzes over 200 carefully selected papers to provide concise data sets and methodology for estimation of bioaccumulation factors for tritium and isotopes of strontium, cesium, iodine, manganese, and cobalt in major biotic components of freshwater environments. Bioaccumulation factors of different tissues are distinguished where significant differences occur. Since conditions in the laboratory are often unnatural in terms of chemical and ecological relationships, this review was restricted as far as possible to bioaccumulation factors determined for natural systems. Because bioaccumulation factors were not available for some shorter-lived radionuclides, a methodology for converting bioaccumulation factors of stable isotopes to those of shorter-lived radionuclides was derived and utilized. The bioaccumulation factor for a radionuclide in a given organism or tissue may exhibit wide variations among bodies of water that are related to differences in ambient concentrations of stable-element and carrier-element analogues. To account for these variations, simple models are presented that relate bioaccumulation factors to stable-element and carrier-element concentrations in water. The effects of physicochemical form and other factors in causing deviations from these models are discussed. Bioaccumulation factor data are examined in the context of these models, and bioaccumulation factor relations for the selected radionuclides are presented

  15. Cyanobacteria and cyanotoxins in freshwaters of Uruguay

    Directory of Open Access Journals (Sweden)

    Sylvia Bonilla

    2015-12-01

    Full Text Available Cyanobacterial blooms are a worldwide environmental problem. This phenomenon is typically associated with eutrophication (nutrient enrichment and changes in hydrology. In this study we analysed the distribution of planktonic cyanobacteria in Uruguay and their toxins (microcystin, saxitoxin and cylindrospermopsin, working with an interagency team (OSE, DINAMA, IM, University of the Republic and IIBCE. An historical data base (n = 3061 for 64 ecosystems, years 1980-2014 was generated. Differences between lotic and lentic ecosystems were found in terms of chlorophyll a and nutrient concentrations, usually indicating eutrophication. Two geo-referenced maps for the country were generated with cyanobacteria biomass indicators and the most relevant toxin (microcystin, according to risk levels suggested by the World Health Organization for recreational waters. The areas of greatest risk of exposure were the reservoirs of large rivers (Uruguay and Río Negro and Río de la Plata beaches. In the second part of the study, up to 20 mg L-1of microcystin was quantified in bloom (scum samples, as well as the presence of genes that suggest more microcystin varieties, potentially with greater toxicity. This study provides basic information about the distribution of cyanobacteria in Uruguayan freshwaters that will be useful for national monitoring programs and scientific research.

  16. Organic environmental poisons in Norwegian freshwater fish

    International Nuclear Information System (INIS)

    According to this article, the level of organic poisons in Norwegian freshwater fish is, on the whole, is too small to threaten human health. It has been found, however, that liver from some species such as burbot, from some lakes, should not be eaten. These lakes are found to contain higher levels of PCB (polychlorinated biphenyls) and DDT (dichlorodiphenyltrichloroethane). Previously, pregnant or breast-feeding women anywhere in Norway have been advised not to eat pike, large perch or large trout because of too much mercury. Other people should not eat these species more often than once per month. In general, the level of organic environmental poisons is higher in the southern part of the country than in the northern part. The sediments of the lakes in large parts of South Norway are contaminated with lead, mercury and cadmium as compared with the conditions before the industrial revolution. However, the level of metals in the lake sediments are relatively low, and these substances are unlikely to appear in the food chain, by and large. The anthropogenic emission of lead was insignificant before the industrial revolution. The exception of lead from German mining industry in the 1700s

  17. Investigation of strength properties of freshwater ice

    Directory of Open Access Journals (Sweden)

    Bragov A.

    2015-01-01

    Full Text Available A study of the strength and deformation properties of freshwater ice under compression, tension and shear in a wide range of strain rates (10−4 − 3 ⋅ 103 s−1 and temperatures of − 5∘ C, − 20∘ C, − 40∘ C and − 60∘ C was performed. Static stress-strain curves of ice under compression were obtained on which the identified strength properties of ice as well as compressive modulus. To determine the mechanical properties of ice at high-speed loading the Kolsky method was used with various embodiments of split Hopkinson bar. The deformation curves were obtained at various loading conditions. Thereon breaking points were defined as well as their dependence on the strain rate and temperature. Also static and dynamic strength properties of ice at splitting and circular shear were defined. Increase in the dynamic strength properties upon the static ones for all loading conditions was marked.

  18. Feeding level and frequency for freshwater angelfish

    Directory of Open Access Journals (Sweden)

    Felipe de Azevedo Silva Ribeiro

    2012-06-01

    Full Text Available The objective of this study was to determine the optimal feeding level and feeding frequency for the culture of freshwater angelfish (Pterophyllum scalare. A randomized block design in a factorial scheme (3 × 2 with three feeding levels (30, 60 and 90 g/kg of body weight (BW/day and two feeding frequencies (1x and 2x/day was set up in duplicate, representing 24 experimental units. Data were analyzed using two-way ANOVA and the Tukey test for comparison between means. After 84 days, results indicated that both factors influenced fish performance. No interaction between these factors was, however, observed. Increased feeding level and feeding frequency resulted in increased feed intake. The feed conversion ratio was negatively affected by feeding level, but not affected by feeding frequency. Final weights were higher when fish were fed twice daily, at levels of 60 or 90 g/kg BW/day. Specific growth rate was higher when fish received 60 or 90 g/kg BW/day, regardless of the feeding frequency. Survival was not affected by any treatment, with mean survival rates higher than 90%. It is recommended that juveniles be fed at a level of 60 g/kg BW/day with a minimum of two meals per day, to attain optimal survival, growth and feed efficiency.

  19. Flavobacterium procerum sp. nov., isolated from freshwater.

    Science.gov (United States)

    Feng, Qingqing; Han, Lu; Yuan, Xin; Tan, Xu; Gao, Yuan; Lv, Jie

    2015-08-01

    A Gram-reaction-negative, strictly aerobic, yellow-pigmented, rod-shaped bacterium, designated strain T3T, was isolated from freshwater of Chishui River flowing through Maotai town, Guizhou, south-west China. Analysis of the16S rRNA gene sequence indicated that strain T3T was a member of the genus Flavobacterium and closely related to Flavobacterium resistens DSM 19382T (96.8 %). The novel strain was able to grow at 10-34 °C (optimum 28 °C), pH 6.0-11.0 (optimum pH 8.0-9.0) and with 0-2.0 % (w/v) NaCl (optimum 0 %). The major polar lipids were phosphatidylethanolamine, two unknown glycolipids, five unknown aminolipids and four unidentified lipids, and the major respiratory quinone was MK-6. The predominant fatty acids were C16  :  1ω7c and/or C16  :  1ω6c and iso-C15  :  0. The DNA G+C content of the strain was 36 mol  %. Based on these data, strain T3T represents a novel species of the genus Flavobacterium, for which the name Flavobacterium procerum sp. nov. is proposed. The type strain is T3T ( = CGMCC 1.12926T = JCM 30113T). PMID:25969476

  20. The International Editorship of Freshwater Systems

    Directory of Open Access Journals (Sweden)

    Karl E. Havens

    2001-01-01

    Full Text Available It is my pleasure to announce that two distinguished internationalscientists have joined the editorship of the FreshwaterSystems domain of TheScientificWorldJOURNAL — Professor BrijGopal of Jawaharlal Nehru University (India and Dr. Manual Gra柠of the Universityof Coimbra (Portugal. Professor Gopal is the Secretary General of the NationalInstitute of Ecology, Editor of the InternationalJournal of Ecology & Environmental Science,and Chairman of the SIL (International Association of Theoretical and AppliedLimnology Committee on Limnology in Developing Countries. His research interestsinclude the ecology, biogeochemistry and biodiversity of wetland ecosystems,the management of wetlands as an integral part of the watershed, and wetlandwater policy–related issues. Dr. Gra柠is a stream ecologist whose researchinterests include the two general areas of organic matter decomposition andbiological monitoring. His specific areas of research focus include quantificationof organic matter and other chemical changes in decomposing leaves, the ecologyof aquatic hyphomycetes, and the ecology of animals feeding on detritus. Hisresearch dealing with biological monitoring is carried out in close cooperationwith the paper and mining industries, facilitating the practical applicationof his work.

  1. Dynamic Route Shortening and Route Repairing Mechanism for Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    T. R. Rangaswamy

    2012-01-01

    Full Text Available Problem statement: Ad hoc Networks are wireless networks without any fixed infrastructure. The network topology changes frequently and unpredictably due to the random movement of the nodes. The ad hoc on Demand Distant Vector Routing (AODV protocol works in a dynamic fashion, by establishing a route on demand and continues that route until it breaks. Due to the changing network topology of ad hoc networks, if other routes with less hop count become available, the network topology is not able to adapt until the route break occurs. Hence in the route shortening scheme is some redundant nodes in the active route is replaced with a node that is not on the active route. When there is any link failure between any two nodes, the alternative route with optimum route to be constructed and not sending RRER message to the source node to initiate the route discovery process again. Approach: This study proposes a new routing protocol called, Dynamic Route Shortening and Repairing mechanism (DRSR. The route shortening is incorporated with route repairing mechanism, to improve the performance of the AODV. The route shortening scheme works by replacing some redundant nodes in the active route, with a node that is not on the active route. If there is a link failure between the two nodes, the route repairing mechanism repairs the route, by using the nodes that are close enough to the route to overhear the message. Whenever the links go down, the DRSR replaces the failed links with the optimum route that is adjacent to the main route and not sending and RRER message to the source node to initiate the route discovery process again. The alternative route construction process could be initiated at any time, not just when a route has failed. The dynamically constructed alternative route’s information is passed on to the upstream nodes, which then determine by themselves when to direct their packets to the Normal 0 false false false EN-US X

  2. Consumption of freshwater fish by recreational and native freshwater anglers in the upper St-Maurice (Quebec, Canada) and estimation of the intake of methylmercury in humans

    International Nuclear Information System (INIS)

    Hydro-Quebec is planning to build two hydroelectric reservoirs in the upper Saint-Maurice River, which would flood about 80% of the surrounding area. The methylmercury (MeHg) content in freshwater fish will therefore tend to increase during the first few years. This development will have a direct impact on the amount of MeHg that the actual users of this river section are exposed to. The objective of this study is to assess the consumption of local fish of these target groups using a Monte-Carlo approach. This study is part of a larger research project aimed at assessing human exposure and the health risks related to MeHg contamination in local fish. The fish consumption rate for recreational freshwater anglers was calculated using the duration of the average annual fishing trip, the average number of catches per species, the average fish weight per species exceeding a specific length of fish usually caught, and the edible portion of fish consumed. This rate was calculated for the native communities based on the total number of meals per year per species, the average fish weight per species, and the edible portion. Based on these calculations, average intake for sport fishermen is estimated at 6.9 g/day (sd = 6.4). This value is 5 to 25 times lower on average than for other North American native communities. However, it must be pointed out that the food habits of the native population were very similar to those of non-native populations; less than 30% of the food comes from traditional sources

  3. Black and Korean: Racialized Development and the Korean American Subject in Korean/American Fiction

    Directory of Open Access Journals (Sweden)

    Jeehyun Lim

    2013-09-01

    Full Text Available This article examines the representation of the encounters and exchanges between Asian and black Americans in Sŏk-kyŏng Kang’s “Days and Dreams,” Heinz Insu Fenkl’s Memories of My Ghost Brother, and Chang-rae Lee’s A Gesture Life. While one popular mode of looking at Asian and black Americans relationally in the postwar era is to compare the success of Asian American assimilation to the failure of black Americans, Lim argues that such a mode of comparison cannot account for the ways in which Asian American racialization takes places within the global currents of militarism and migration. Against the popular view that attributes Asian American success to cultural difference, Lim relies on political scientist Claire Kim’s understanding of culture as something that is constructed in the process of racialization to explore how the above texts imagine the terms of comparative racialization between black and Asian Americans. The black-Korean encounters in these texts demand a heuristic of comparative racialization that goes beyond the discussion of the black-white binary as a national construct and seeks the reification and modification of this racial frame as it travels along the routes of US military and economic incursions in the Pacific. Lim suggests that the literary imagining of black-Korean encounters across the Pacific illustrates race and racialization as effects of a regime of economic development that is supported by military aggression.

  4. The African American Image in American Cinema.

    Science.gov (United States)

    Bourne, St. Clair

    1990-01-01

    Political conditions have influenced the screen images of U.S. cinema, and the images of African Americans have reflected prevailing social stereotypes. The history of African-American representation in films is traced, and it is noted that the tendency to portray African Americans stereotypically has not changed. (SLD)

  5. Historiography, American Theatre, and the First Americans.

    Science.gov (United States)

    Jenkins, Linda Walsh

    American theatre history should include a study of Native American performances, since these performances are rich with "American" symbolic materials such as imagery, symbols, and heraldic visions of animals and landscapes. Indian cultures understood the importance of performance for both the visionary and the community at large. Even the pow-wow…

  6. Integrated Routing Protocol for Opportunistic Networks

    Directory of Open Access Journals (Sweden)

    Anshul Verma

    2011-03-01

    Full Text Available In opportunistic networks the existence of a simultaneous path is not assumed to transmit a message between a sender and a receiver. Information about the context in which the users communicate is a key piece of knowledge to design efficient routing protocols in opportunistic networks. But this kind of information is not always available. When users are very isolated, context information cannot be distributed, and cannot be used for taking efficient routing decisions. In such cases, context oblivious based schemes are only way to enable communication between users. As soon as users become more social, context data spreads in the network, and context based routing becomes an efficient solution. In this paper we design an integrated routing protocol that is able to use context data as soon as it becomes available and falls back to dissemination-based routing when context information is not available. Then, we provide a comparison between Epidemic and PROPHET, these are representative of context oblivious and context aware routing protocols. Our results show that integrated routing protocol is able to provide better result in term of message delivery probability and message delay in both cases when context information about users is available or not.

  7. Tenancy and African American Marriage in the Postbellum South.

    Science.gov (United States)

    Bloome, Deirdre; Muller, Christopher

    2015-10-01

    The pervasiveness of tenancy in the postbellum South had countervailing effects on marriage between African Americans. Tenancy placed severe constraints on African American women's ability to find independent agricultural work. Freedwomen confronted not only planters' reluctance to contract directly with women but also whites' refusal to sell land to African Americans. Marriage consequently became one of African American women's few viable routes into the agricultural labor market. We find that the more counties relied on tenant farming, the more common was marriage among their youngest and oldest African American residents. However, many freedwomen resented their subordinate status within tenant marriages. Thus, we find that tenancy contributed to union dissolution as well as union formation among freedpeople. Microdata tracing individuals' marital transitions are consistent with these county-level results. PMID:26223562

  8. Agent routing algorithm in wireless sensor networks

    Science.gov (United States)

    Zhang, Yuqing; Yang, Shuqun

    2013-03-01

    Wireless sensor networks are a new technology of information acquisition and processing, so they are widely used in all kinds of fields. In the paper we introduce Agent technology into the wireless sensor network, conduct a in-depth research on the four routing schemes, and propose a new improved routing scheme, which considers the energy consumption of both nodes and path. Furthermore, The scheme we proposed has efficient routing function, can balance the energy consumption of nodes and extends the lifetime of the network in a more efficient way.

  9. Effective Privacy-Preserving Online Route Planning

    DEFF Research Database (Denmark)

    Ruiz Vicente, Carmen; Assent, Ira; Jensen, Christian Søndergaard

    2011-01-01

    An online Route Planning Service (RPS) computes a route from one location to another. Current RPSs such as Google Maps require the use of precise locations. However, some users may not want to disclose their source and destination locations due to privacy concerns. An approach that supplies fake...... locations to an existing service incurs a substantial loss of quality of service, and the service may well return a result that may be not helpful to the user. We propose a solution that is able to return accurate route planning results when source and destination regions are used in order to achieve...

  10. Dynamic telecast Routing with Security Intensification

    Directory of Open Access Journals (Sweden)

    BeerthiSahadev

    2011-09-01

    Full Text Available Security has become one of the majorissues for data communication over wired and wireless networks. Different from the past work on the designs of network security algorithms and system infrastructures, we will propose a dynamic broadcast routing algorithm that could randomize delivery paths for data transmission. The algorithm is easy to implement and compatible with popular routing protocols, such as the Routing Information Protocol in wired networks and Destination-Sequenced Distance Vector protocol in wireless networks , without introducing extra control messages. The simulation results have been verified from the proposed algorithm and it shows the capability of the proposed algorithm.

  11. Analysis of Enhanced Associativity Based Routing Protocol

    Directory of Open Access Journals (Sweden)

    Said A. Shaar

    2006-01-01

    Full Text Available This study introduces an analysis to the performance of the Enhanced Associativity Based Routing protocol (EABR based on two factors; Operation complexity (OC and Communication Complexity (CC. OC can be defined as the number of steps required in performing a protocol operation, while CC can be defined as the number of messages exchanged in performing a protocol operation[1]. The values represent the worst-case analysis. The EABR has been analyzed based on CC and OC and the results have been compared with another routing technique called ABR. The results have shown that EABR can perform better than ABR in many circumstances during the route reconstruction.

  12. Stability Analysis of Path-vector Routing

    CERN Document Server

    Dimitri, Papadimitriou

    2012-01-01

    Most studies on path-vector routing stability have been conducted empirically by means of ad-hoc analysis of BGP data traces. None of them consider prior specification of an analytic method including the use of stability measurement metrics for the systematic analysis of BGP traces and associated meta-processing for determining the local state of the routing system. In this paper, we define a set of metrics that characterize the local stability properties of path-vector routing such as BGP (Border Gateway Protocol). By means of these stability metrics, we propose a method to analyze the effects of BGP policy- and protocol-induced instability on local routers.

  13. Partially dynamic vehicle routing - models and algorithms

    DEFF Research Database (Denmark)

    Larsen, Allan; Madsen, Oli B.G.; Solomon, M.

    2002-01-01

    In this paper we propose a framework for dynamic routing systems based on their degree of dynamism. Next, we consider its impact on solution methodology and quality. Specifically, we introduce the Partially Dynamic Travelling Repairman Problem and describe several dynamic policies to minimize...... routing costs. The results of our computational study indicate that increasing the dynamic level results in a linear increase in route length for all policies studied. Furthermore, a Nearest Neighbour policy performed, on the average, uniformly better than the other dispatching rules studied. Among these...

  14. Performance Analysis of Route Discovery by Cross Layer Routing Protocol- RDCLRP

    Directory of Open Access Journals (Sweden)

    Mehajabeen Fatima

    2013-06-01

    Full Text Available Wired and wireless network is based on the TCP / IP architecture but it is not sufficient to cope with the dynamics of the MANET. Cross layer design can be an alternative architecture for MANET. Frequent route break is one of the major problems of mobile adhoc network (MANET. Path breaks due to less available battery power and mobility of nodes. Most of the battery power is consumed in flooding of control packets. A key challenge in the design of efficient routing protocol is to reduce link breakage and flooding of control packets. Route breakage can be reduced if the possibility of route breakage is predicted and a handoff is done without drop of data packets. If route breakage is reduced, the more battery power will be available with nodes. In turn it reduces the possibility of route breakage and the possibility of flooding. This is a cumulative effect. So a novel preemptive route repair algorithm is proposed named as RDCLRP- Route discovery by cross layer routing protocol to reduce frequency of control packet flooding and route breakage. Three variants of RDCLRP and their results are illustrated. In this paper, the impact of the number of nodes on performance of RDCLRP are investigated and analyzed. The results show 55.6% reduction in link breakage, 14.7% improvement in residual battery power and an average of 6.7% increase in throughput compared to basic AODV.

  15. A SURVEY ON THE ALGORITHMIC APPROACH USED IN ROUTING FOR PLACEMENT AND ROUTING FLOW

    Directory of Open Access Journals (Sweden)

    KOMAL

    2014-06-01

    Full Text Available Routing is one of the long-drawn-out processes after placement in VLSI design. The routing provides the path for nets on chip to interconnect the pins on the pads or blocks at the chip boundary. This paper provides a systematic insight of interconnect of nets in ‘Placement and Routing Flow’ based on various methods (global routing and detailed routing. Further, the work reported so far has been compared with a multiple techniques for multiple factors such as reduction in wire-length, short execution time, fast and accurate congestion, improvement in complexity, signal integrity and crosstalk. Here the methodologies adopts are the Routing congestion estimator algorithm, Ant Colony Optimization. Firefly Algorithm, Monotonic Staircase Routing and so on. It is also observed that Pattern Based Routing is much faster than the Maze Routing, and the improved parameters are there is no over-congestion and 100% routablity with Monotonic Staircase Channels. zero overflow by Simulated-Evolution(Sim-E, and Complexity improved by a Fuzzified Approach Towards Global Routing.

  16. Mechanical challenges to freshwater residency in sharks and rays.

    Science.gov (United States)

    Gleiss, Adrian C; Potvin, Jean; Keleher, James J; Whitty, Jeff M; Morgan, David L; Goldbogen, Jeremy A

    2015-04-01

    Major transitions between marine and freshwater habitats are relatively infrequent, primarily as a result of major physiological and ecological challenges. Few species of cartilaginous fish have evolved to occupy freshwater habitats. Current thought suggests that the metabolic physiology of sharks has remained a barrier to the diversification of this taxon in freshwater ecosystems. Here, we demonstrate that the physical properties of water provide an additional constraint for this species-rich group to occupy freshwater systems. Using hydromechanical modeling, we show that occurrence in fresh water results in a two- to three-fold increase in negative buoyancy for sharks and rays. This carries the energetic cost of lift production and results in increased buoyancy-dependent mechanical power requirements for swimming and increased optimal swim speeds. The primary source of buoyancy, the lipid-rich liver, offers only limited compensation for increased negative buoyancy as a result of decreasing water density; maintaining the same submerged weight would involve increasing the liver volume by very large amounts: 3- to 4-fold in scenarios where liver density is also reduced to currently observed minimal levels and 8-fold without any changes in liver density. The first data on body density from two species of elasmobranch occurring in freshwater (the bull shark Carcharhinus leucas, Müller and Henle 1839, and the largetooth sawfish Pristis pristis, Linnaeus 1758) support this hypothesis, showing similar liver sizes as marine forms but lower liver densities, but the greatest negative buoyancies of any elasmobranch studied to date. Our data suggest that the mechanical challenges associated with buoyancy control may have hampered the invasion of freshwater habitats in elasmobranchs, highlighting an additional key factor that may govern the predisposition of marine organisms to successfully establish in freshwater habitats. PMID:25573824

  17. Anthropogenic litter in urban freshwater ecosystems: distribution and microbial interactions.

    Directory of Open Access Journals (Sweden)

    Timothy Hoellein

    Full Text Available Accumulation of anthropogenic litter (i.e. garbage; AL and its ecosystem effects in marine environments are well documented. Rivers receive AL from terrestrial habitats and represent a major source of AL to marine environments, but AL is rarely studied within freshwater ecosystems. Our objectives were to 1 quantify AL density in urban freshwaters, 2 compare AL abundance among freshwater, terrestrial, and marine ecosystems, and 3 characterize the activity and composition of AL biofilms in freshwater habitats. We quantified AL from the Chicago River and Chicago's Lake Michigan shoreline, and found that AL abundance in Chicago freshwater ecosystems was comparable to previously reported data for marine and terrestrial ecosystems, although AL density and composition differed among habitats. To assess microbial interactions with AL, we incubated AL and natural substrates in 3 freshwater ecosystems, quantified biofilm metabolism as gross primary production (GPP and community respiration (CR, and characterized biofilm bacterial community composition via high-throughput sequencing of 16S rRNA genes. The main driver of biofilm community composition was incubation location (e.g., river vs pond, but there were some significant differences in biofilm composition and metabolism among substrates. For example, biofilms on organic substrates (cardboard and leaves had lower GPP than hard substrates (glass, plastic, aluminum and tiles. In addition, bacterial communities on organic substrates were distinct in composition from those on hard substrates, with higher relative abundances of bacteria associated with cellulose decomposition. Finally, we used our results to develop a conceptual diagram designed to unite the study of AL in terrestrial and freshwater environments with the well-established field of marine debris research. We suggest this broad perspective will be useful for future studies which synthesize AL sources, ecosystem effects, and fate across

  18. Anthropogenic litter in urban freshwater ecosystems: distribution and microbial interactions.

    Science.gov (United States)

    Hoellein, Timothy; Rojas, Miguel; Pink, Adam; Gasior, Joseph; Kelly, John

    2014-01-01

    Accumulation of anthropogenic litter (i.e. garbage; AL) and its ecosystem effects in marine environments are well documented. Rivers receive AL from terrestrial habitats and represent a major source of AL to marine environments, but AL is rarely studied within freshwater ecosystems. Our objectives were to 1) quantify AL density in urban freshwaters, 2) compare AL abundance among freshwater, terrestrial, and marine ecosystems, and 3) characterize the activity and composition of AL biofilms in freshwater habitats. We quantified AL from the Chicago River and Chicago's Lake Michigan shoreline, and found that AL abundance in Chicago freshwater ecosystems was comparable to previously reported data for marine and terrestrial ecosystems, although AL density and composition differed among habitats. To assess microbial interactions with AL, we incubated AL and natural substrates in 3 freshwater ecosystems, quantified biofilm metabolism as gross primary production (GPP) and community respiration (CR), and characterized biofilm bacterial community composition via high-throughput sequencing of 16S rRNA genes. The main driver of biofilm community composition was incubation location (e.g., river vs pond), but there were some significant differences in biofilm composition and metabolism among substrates. For example, biofilms on organic substrates (cardboard and leaves) had lower GPP than hard substrates (glass, plastic, aluminum and tiles). In addition, bacterial communities on organic substrates were distinct in composition from those on hard substrates, with higher relative abundances of bacteria associated with cellulose decomposition. Finally, we used our results to develop a conceptual diagram designed to unite the study of AL in terrestrial and freshwater environments with the well-established field of marine debris research. We suggest this broad perspective will be useful for future studies which synthesize AL sources, ecosystem effects, and fate across multiple ecosystem

  19. Large-scale degradation of Amazonian freshwater ecosystems.

    Science.gov (United States)

    Castello, Leandro; Macedo, Marcia N

    2016-03-01

    Hydrological connectivity regulates the structure and function of Amazonian freshwater ecosystems and the provisioning of services that sustain local populations. This connectivity is increasingly being disrupted by the construction of dams, mining, land-cover changes, and global climate change. This review analyzes these drivers of degradation, evaluates their impacts on hydrological connectivity, and identifies policy deficiencies that hinder freshwater ecosystem protection. There are 154 large hydroelectric dams in operation today, and 21 dams under construction. The current trajectory of dam construction will leave only three free-flowing tributaries in the next few decades if all 277 planned dams are completed. Land-cover changes driven by mining, dam and road construction, agriculture and cattle ranching have already affected ~20% of the Basin and up to ~50% of riparian forests in some regions. Global climate change will likely exacerbate these impacts by creating warmer and dryer conditions, with less predictable rainfall and more extreme events (e.g., droughts and floods). The resulting hydrological alterations are rapidly degrading freshwater ecosystems, both independently and via complex feedbacks and synergistic interactions. The ecosystem impacts include biodiversity loss, warmer stream temperatures, stronger and more frequent floodplain fires, and changes to biogeochemical cycles, transport of organic and inorganic materials, and freshwater community structure and function. The impacts also include reductions in water quality, fish yields, and availability of water for navigation, power generation, and human use. This degradation of Amazonian freshwater ecosystems cannot be curbed presently because existing policies are inconsistent across the Basin, ignore cumulative effects, and overlook the hydrological connectivity of freshwater ecosystems. Maintaining the integrity of these freshwater ecosystems requires a basinwide research and policy framework

  20. Large-scale degradation of Amazonian freshwater ecosystems.

    Science.gov (United States)

    Castello, Leandro; Macedo, Marcia N

    2016-03-01

    Hydrological connectivity regulates the structure and function of Amazonian freshwater ecosystems and the provisioning of services that sustain local populations. This connectivity is increasingly being disrupted by the construction of dams, mining, land-cover changes, and global climate change. This review analyzes these drivers of degradation, evaluates their impacts on hydrological connectivity, and identifies policy deficiencies that hinder freshwater ecosystem protection. There are 154 large hydroelectric dams in operation today, and 21 dams under construction. The current trajectory of dam construction will leave only three free-flowing tributaries in the next few decades if all 277 planned dams are completed. Land-cover changes driven by mining, dam and road construction, agriculture and cattle ranching have already affected ~20% of the Basin and up to ~50% of riparian forests in some regions. Global climate change will likely exacerbate these impacts by creating warmer and dryer conditions, with less predictable rainfall and more extreme events (e.g., droughts and floods). The resulting hydrological alterations are rapidly degrading freshwater ecosystems, both independently and via complex feedbacks and synergistic interactions. The ecosystem impacts include biodiversity loss, warmer stream temperatures, stronger and more frequent floodplain fires, and changes to biogeochemical cycles, transport of organic and inorganic materials, and freshwater community structure and function. The impacts also include reductions in water quality, fish yields, and availability of water for navigation, power generation, and human use. This degradation of Amazonian freshwater ecosystems cannot be curbed presently because existing policies are inconsistent across the Basin, ignore cumulative effects, and overlook the hydrological connectivity of freshwater ecosystems. Maintaining the integrity of these freshwater ecosystems requires a basinwide research and policy framework

  1. Behavior of technetium in freshwater environments

    International Nuclear Information System (INIS)

    In a previous study, /sup 95m/Tc, as a pertechnetate, was released to a small, experimental, freshwater pond, and the concentrations were determined in biotic and abiotic components of the pond ecosystem. A simple mathematical model was developed to predict the concentration of /sup 95m/Tc in fish and snails. Results from this study indicated that uptake through the food chain was an important source of technetium to the higher trophic levels (i.e., fish). In the current study, an experimental pond was spiked with /sup 95m/Tc in the pertechnetate form, and the concentrations of /sup 95m/Tc were measured in the lower trophic levels. Emphasis was placed on measuring the concentration of /sup 95m/Tc in zooplankton, benthic invertebrates, and the aquatic macrophyte Elodea canadensis. Fish were excluded from the pond to allow the development of a large zooplankton population. The concentration of /sup 95m/Tc in water decreased from 0.75 Bq/mL 1 h after the pond was spiked, to 0.21 Bq/mL at 20 d. Throughout the experiment, at least 98% of the /sup 95m/Tc in the water was in the dissolved fraction (0.4 μm). Zooplankton accumulated /sup 95m/Tc rapidly, having concentration factors (Bq/g sample wet wt. divided by Bq/g water) ranging from 3 at 4 h to 36 at 20 d. Concentration factors ranged from 3 to 8 for benthic insects and from 1 to 62 for the aquatic macrophyte

  2. A multicast routing algorithm with multiple trees

    Institute of Scientific and Technical Information of China (English)

    Cui Xunxue; Gao Wei; Fang Hongyu

    2005-01-01

    Quality of service (QoS) multicast routing has continued to be a very important research topic in the Internet.A method of multicast routing is proposed to simultaneously optimize several parameters based on multiobjective genetic algorithm, after the related work is reviewed. The contribution lies on that the selection process of such routing is treated with multiobjective optimization. Different quality criterions in IP network are taken into account for multicast communications. A set of routing trees is generated to approximate the Pareto front of multicast problem. Multiple trees can be selected from the final set of nondominated solutions, and applied to obtain a good overall link cost and balance traffic distribution according to some simulation results.

  3. Rich Vehicle Routing Problems and Applications

    DEFF Research Database (Denmark)

    Wen, Min

    of these problems was motivated by our cooperation with industrial companies, particularly Transvision A/S and its client distributors, and Danish Crown. The models and methods proposed in the thesis are general and can be applied to practical routing problems arising in many other distribution companies as well...... the company’s solution in terms of all the objectives, including the travel time, customer waiting and daily workload balances, under the given constraints considered in the work. Finally, we address an integrated vehicle routing and driver scheduling problem, in which a large number of practical constraints......The Vehicle Routing Problem (VRP) is one of the most important and challenging optimization problems in the field of Operations Research. It was introduced by Dantzig and Ramser (1959) and defined as the problem of designing the optimal set of routes for a fleet of vehicles in order to serve...

  4. A new routing assignment model for Internet

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper builds a new traffic assignment model for Internet. The routing policy based on this model can realize load splitting in a network automatically, which overcomes the shortcoming of OSPF and satisfies the load balancing requirement of IETF.

  5. Multicriteria Evolutionary Weather Routing Algorithm in Practice

    Directory of Open Access Journals (Sweden)

    Joanna Szlapczynska

    2013-03-01

    Full Text Available The Multicriteria Evolutionary Weather Routing Algorithm (MEWRA has already been introduced by the author on earlier TransNav 2009 and 2011 conferences with a focus on theoretical application to a hybrid-propulsion or motor-driven ship. This paper addresses the topic of possible practical weather routing applications of MEWRA. In the paper some practical advantages of utilizing Pareto front as a result of multicriteria optimization in case of route finding are described. The paper describes the notion of Pareto-optimality of routes along with a simplified, easy to follow, example. It also discusses a choice of the most suitable ranking method for MEWRA (a comparison between Fuzzy TOPSIS and Zero Unitarization Method is presented. In addition to that the paper briefly outlines a commercial application of MEWRA.

  6. Quantum chemistry-assisted synthesis route development

    International Nuclear Information System (INIS)

    We have been investigating “quantum chemistry-assisted synthesis route development” using in silico screenings and applied the method to several targets. Another example was conducted to develop synthesis routes for a urea derivative, namely 1-(4-(trifluoromethyl)-2-oxo-2H-chromen-7-yl)urea. While five synthesis routes were examined, only three routes passed the second in silico screening. Among them, the reaction of 7-amino-4-(trifluoromethyl)-2H-chromen-2-one and O-methyl carbamate with BF3 as an additive was ranked as the first choice for synthetic work. We were able to experimentally obtain the target compound even though its yield was as low as 21 %. The theoretical result was thus consistent with that observed. The summary of transition state data base (TSDB) is also provided. TSDB is the key to reducing time of in silico screenings

  7. Integrating routing decisions in public transportation problems

    CERN Document Server

    Schmidt, Marie E

    2014-01-01

    This book treats three planning problems arising in public railway transportation planning: line planning, timetabling, and delay management, with the objective to minimize passengers’ travel time. While many optimization approaches simplify these problems by assuming that passengers’ route choice is independent of the solution, this book focuses on models which take into account that passengers will adapt their travel route to the implemented planning solution. That is, a planning solution and passengers’ routes are determined and evaluated simultaneously. This work is technically deep, with insightful findings regarding complexity and algorithmic approaches to public transportation problems with integrated passenger routing. It is intended for researchers in the fields of mathematics, computer science, or operations research, working in the field of public transportation from an optimization standpoint. It is also ideal for students who want to gain intuition and experience in doing complexity proofs ...

  8. Quantum chemistry-assisted synthesis route development

    Energy Technology Data Exchange (ETDEWEB)

    Hori, Kenji; Sumimoto, Michinori [Graduate School of Science and Engineering, Yamaguchi University, Tokiwadai, Ube, Yamaguchi 755-8611 (Japan); Murafuji, Toshihiro [Graduate School of Medicine, Yamaguchi University, Yamaguchi, Yamaguchi 753-8512 (Japan)

    2015-12-31

    We have been investigating “quantum chemistry-assisted synthesis route development” using in silico screenings and applied the method to several targets. Another example was conducted to develop synthesis routes for a urea derivative, namely 1-(4-(trifluoromethyl)-2-oxo-2H-chromen-7-yl)urea. While five synthesis routes were examined, only three routes passed the second in silico screening. Among them, the reaction of 7-amino-4-(trifluoromethyl)-2H-chromen-2-one and O-methyl carbamate with BF{sub 3} as an additive was ranked as the first choice for synthetic work. We were able to experimentally obtain the target compound even though its yield was as low as 21 %. The theoretical result was thus consistent with that observed. The summary of transition state data base (TSDB) is also provided. TSDB is the key to reducing time of in silico screenings.

  9. Advances in technology for integrated route analysis

    Energy Technology Data Exchange (ETDEWEB)

    Carey, N.T.; George, P.J.; Khamhawi, K. [SAGE Engineering Ltd., Bath (United Kingdom)

    1998-12-31

    Pipeline and cable routes are becoming ever complex with routes being chosen in increasingly remote and technically demanding areas. Clients now demand greater information and analysis from the surveys and interpretations. By utilising a range of leading edge equipment, greater information can be obtained, visualised and analysed than ever before. Three case studies are presented, indicating how such technology has been employed to provide the client with a greater understanding of complex engineering projects, and what additional technology could have been utilised to further enhance the project. Examples of data, systems and project management used on two major pipe routes and one major cable route are presented. Swath Bathymetry (ISIS), 3D visualisation (Fledermaus), cone penetrometer testing (SAGE Miniature CPT), GIS databases (INfoXProfessional), and the use of pipeline stress analysis, upheaval buckling and rock dump optimisation software (SAFE Profile) are all examined. (author)

  10. Recommended Cross-Desert Driving Route

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    Beijing - Duolun - Dalai Nur- Hexigten Banner -Saihanba - Weichang - Luanping - Miyun - Beijing. Along this 1,600-kilometer route is a 150-kin section(between Duolun and Darhan) of desert with no surfaced road - a paradise for desert drivers.

  11. Language and Spatial Cognition in Route Navigation

    Institute of Scientific and Technical Information of China (English)

    宋娟

    2013-01-01

    The purpose of this study is to investigate the contrast between using street names or landmarks to process spatial in⁃structions. The study confirms the special cognitive status of landmarks in the mental representation of routes.

  12. Dams and Obstructions along Iowa's Canoe Routes

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — This dataset represents obstruction to canoe and boat users of the canoe routes of Iowa. This may represent actual dams, rock dams (natural or man made), large...

  13. Latent variables and route choice behavior

    DEFF Research Database (Denmark)

    Prato, Carlo Giacomo; Bekhor, Shlomo; Pronello, Cristina

    2012-01-01

    by proposing and estimating a hybrid model that integrates latent variable and route choice models. Data contain information about latent variable indicators and chosen routes of travelers driving regularly from home to work in an urban network. Choice sets include alternative routes generated with a branch...... and bound algorithm. A hybrid model consists of measurement equations, which relate latent variables to measurement indicators and utilities to choice indicators, and structural equations, which link travelers’ observable characteristics to latent variables and explanatory variables to utilities. Estimation...... results illustrate that considering latent variables (i.e., memory, habit, familiarity, spatial ability, time saving skills) alongside traditional variables (e.g., travel time, distance, congestion level) enriches the comprehension of route choice behavior....

  14. A Multistage Method for Multiobjective Route Selection

    Science.gov (United States)

    Wen, Feng; Gen, Mitsuo

    The multiobjective route selection problem (m-RSP) is a key research topic in the car navigation system (CNS) for ITS (Intelligent Transportation System). In this paper, we propose an interactive multistage weight-based Dijkstra genetic algorithm (mwD-GA) to solve it. The purpose of the proposed approach is to create enough Pareto-optimal routes with good distribution for the car driver depending on his/her preference. At the same time, the routes can be recalculated according to the driver's preferences by the multistage framework proposed. In the solution approach proposed, the accurate route searching ability of the Dijkstra algorithm and the exploration ability of the Genetic algorithm (GA) are effectively combined together for solving the m-RSP problems. Solutions provided by the proposed approach are compared with the current research to show the effectiveness and practicability of the solution approach proposed.

  15. Performance Evaluation of MANET Routing Protocols

    Directory of Open Access Journals (Sweden)

    Hrituparna Paul

    2012-07-01

    Full Text Available The task of finding and sustaining routes in Mobile Ad-hoc Networks (MANETS is an important factor in determining the efficiency of any MANET protocol. MANET characteristically is an autonomous system of mobile nodes connected by wireless links without any centralised infrastructure. Absence of fixed infrastructures and host mobility thus network may experience rapid and unpredictable topology changes. Hence, routing is required in order to perform communication among the entire network. There are several routing protocols namely proactive, reactive and hybrid etc. In this paper we will discuss the active research work on these routing protocols and its performance evaluation. To this end, we adopt a simulation approach, which is more suitable to this kind of analysis

  16. Finding routes in anonymous sensor networks

    OpenAIRE

    Dutra, Renato C.; Barbosa, Valmir C

    2005-01-01

    We consider networks of anonymous sensors and address the problem of constructing routes for the delivery of information from a group of sensors in response to a query by a sink. In order to circumvent the restrictions imposed by anonymity, we rely on using the power level perceived by the sensors in the query from the sink. We introduce a simple distributed algorithm to achieve the building of routes to the sink and evaluate its performance by means of simulations.

  17. Stochastic vehicle routing: from theory to practice

    OpenAIRE

    Weyland, Dennis; Gambardella, Luca Maria; Montemanni, Roberto

    2013-01-01

    In this thesis we discuss practical and theoretical aspects of various stochastic vehicle routing problems. These are combinatorial optimization problems related to the field of transportation and logistics in which input data is (partially) represented in a stochastic way. More in detail, we focus on two-stage stochastic vehicle routing problems and in particular on so-called a priori optimization problems. The results are divided into a theoretical part and a practical part. In fact, the ...

  18. Efficient Networks Communication Routing Using Swarm Intelligence

    OpenAIRE

    Koushal Kumar

    2012-01-01

    As demonstrated by natural biological swarm’s collective intelligence has an abundance of desirable properties for problem-solving like in network routing. The focus of this paper is in the applications of swarm based intelligence in information routing for communication networks. As we know networks are growing and adopting new platforms as new technologies comes. Also according to new demands and requirements networks topologies and its complexity is increasing with time. Thus it is becomin...

  19. Southern Bohemian route of industrial heritage

    OpenAIRE

    Vladimír Dvořák; Blažena Gehinová; Dagmar Škodová Parmová; Eva Jaderná; Eduard Šitler

    2009-01-01

    This paper deals with the industrial heritage and its usage in the frame of tourism service supply. There were three so called Anchor Points selected based on the ERIH methodology in the southern Bohemia. And there were also other regional and important places and points named for the future tourist route. The Southern Bohemian Route of Industrial Heritage was invented around the Anchor Point of Schwarzenberg Channel because of its importance in European heritage and its location next to the ...

  20. Security Conformance for the Dynamically Routed Data

    OpenAIRE

    Suma Patra; Dr.V.Janaki; Priyanka suram; Nalubala Ranjeeth Kumar

    2011-01-01

    Secure transmission of data plays a crucial role in the networks. To improve the security many methodologies have been proposed till now, like cryptographic designs, intrusion detection, dynamic routing etc. In this paper we consider that the data transmission is done by using the concept of dynamic routing. Sometimes the sender may be neglecting the security due to the lack of personal interest, but the receiver has to take the utmost care. In such cases the receiver after forcing the sender...

  1. Light olefins - challenges from new production routes?

    Energy Technology Data Exchange (ETDEWEB)

    Zimmermann, H. [Linde Engineering, Pullach (Germany)

    2007-07-01

    Light Olefins are the building blocks for many modern plastic products and are produced in large quantities. Driven by high crude oil prices, production is shifted to regions with low cost raw materials. Alternatives to the traditional production from Naphta, AGO and other crude products are becoming attractive. This paper evaluates several methods Ethylene and Pro-pylene production economically and also the regional advantageous routes. The analysis includes Steamcracking, dehydrogenation, dehydration of Ethanol, Methanol based routes and olefin conversion by Metathesis. (orig.)

  2. A CONTRIBUTION TO SECURE THE ROUTING PROTOCOL

    OpenAIRE

    Mohammed ERRITALI; Oussama Mohamed Reda; Bouabid El Ouahidi

    2011-01-01

    This work presents a contribution to secure the routing protocol GPSR (Greedy Perimeter StatelessRouting) for vehicular ad hoc networks, we examine the possible attacks against GPSR and securitysolutions proposed by different research teams working on ad hoc network security. Then, we propose asolution to secure GPSR packet by adding a digital signature based on symmetric cryptographygenerated using the AES algorithm and the MD5 hash function more suited to a mobile environment

  3. A CONTRIBUTION TO SECURE THE ROUTING PROTOCOL

    Directory of Open Access Journals (Sweden)

    Mohammed ERRITALI

    2011-10-01

    Full Text Available This work presents a contribution to secure the routing protocol GPSR (Greedy Perimeter StatelessRouting for vehicular ad hoc networks, we examine the possible attacks against GPSR and securitysolutions proposed by different research teams working on ad hoc network security. Then, we propose asolution to secure GPSR packet by adding a digital signature based on symmetric cryptographygenerated using the AES algorithm and the MD5 hash function more suited to a mobile environment

  4. Ising model for packet routing control

    International Nuclear Information System (INIS)

    For packet routing control in computer networks, we propose an Ising model which is defined in order to express competition among a queue length and a distance from a node with a packet to its destination node. By introducing a dynamics for a mean-field value of an Ising spin, we show by computer simulations that effective control of packet routing through priority links is possible

  5. Energy Efficient Routing in Nomadic Networks

    DEFF Research Database (Denmark)

    Kristensen, Mads Darø; Bouvin, Niels Olof

    2007-01-01

    We present an evaluation of a novel energy-efficient routing protocol for mobile ad-hoc networks. We combine two techniques for optimizing energy levels with a well-known routing protocol. We examine the behavior of this combination in a nomadic network setting, where some nodes are stationary...... and have a steady power supply. Protocol optimizations for the nomadic scenario are presented and validated through simulations...

  6. Integrated Routing Protocol for Opportunistic Networks

    OpenAIRE

    Anshul Verma; Dr. Anurag Srivastava

    2012-01-01

    In opportunistic networks the existence of a simultaneous path is not assumed to transmit a message between a sender and a receiver. Information about the context in which the users communicate is a key piece of knowledge to design efficient routing protocols in opportunistic networks. But this kind of information is not always available. When users are very isolated, context information cannot be distributed, and cannot be used for taking efficient routing decisions. In such cases, context o...

  7. Arctic Ocean freshwater as a trigger for abrupt climate change

    Science.gov (United States)

    Bradley, Raymond; Condron, Alan; Coletti, Anthony

    2016-04-01

    The cause of the Younger Dryas cooling remains unresolved despite decades of debate. Current arguments focus on either freshwater from Glacial Lake Agassiz drainage through the St Lawrence or the MacKenzie river systems. High resolution ocean modeling suggests that freshwater delivered to the North Atlantic from the Arctic Ocean through Fram Strait would have had more of an impact on Atlantic Meridional Overturning Circulation (AMOC) than freshwater from the St Lawrence. This has been interpreted as an argument for a MacKenzie River /Lake Agassiz freshwater source. However, it is important to note that although the modeling identifies Fram Strait as the optimum location for delivery of freshwater to disrupt the AMOC, this does not mean the freshwater source came from Lake Agassiz. Another potential source of freshwater is the Arctic Ocean ice cover itself. During the LGM, ice cover was extremely thick - many tens of meters in the Canada Basin (at least), resulting in a hiatus in sediment deposition there. Extreme ice thickness was related to a stagnant circulation, very low temperatures and continuous accumulation of snow on top of a base of sea-ice. This resulted in a large accumulation of freshwater in the Arctic Basin. As sea-level rose and a more modern circulation regime became established in the Arctic, this freshwater was released from the Arctic Ocean through Fram Strait, leading to extensive sea-ice formation in the North Atlantic (Greenland Sea) and a major reduction in the AMOC. Here we present new model results and a review of the paleoceanographic evidence to support this hypothesis. The bottom line is that the Arctic Ocean was likely a major player in causing abrupt climate change in the past, via its influence on the AMOC. Although we focus here on the Younger Dryas, the Arctic Ocean has been repeatedly isolated from the world ocean during glacial periods of the past. When these periods of isolation ended, it is probable that there were significant

  8. Freshwater biodiversity: importance, threats, status and conservation challenges.

    Science.gov (United States)

    Dudgeon, David; Arthington, Angela H; Gessner, Mark O; Kawabata, Zen-Ichiro; Knowler, Duncan J; Lévêque, Christian; Naiman, Robert J; Prieur-Richard, Anne-Hélène; Soto, Doris; Stiassny, Melanie L J; Sullivan, Caroline A

    2006-05-01

    Freshwater biodiversity is the over-riding conservation priority during the International Decade for Action - 'Water for Life' - 2005 to 2015. Fresh water makes up only 0.01% of the World's water and approximately 0.8% of the Earth's surface, yet this tiny fraction of global water supports at least 100000 species out of approximately 1.8 million - almost 6% of all described species. Inland waters and freshwater biodiversity constitute a valuable natural resource, in economic, cultural, aesthetic, scientific and educational terms. Their conservation and management are critical to the interests of all humans, nations and governments. Yet this precious heritage is in crisis. Fresh waters are experiencing declines in biodiversity far greater than those in the most affected terrestrial ecosystems, and if trends in human demands for water remain unaltered and species losses continue at current rates, the opportunity to conserve much of the remaining biodiversity in fresh water will vanish before the 'Water for Life' decade ends in 2015. Why is this so, and what is being done about it? This article explores the special features of freshwater habitats and the biodiversity they support that makes them especially vulnerable to human activities. We document threats to global freshwater biodiversity under five headings: overexploitation; water pollution; flow modification; destruction or degradation of habitat; and invasion by exotic species. Their combined and interacting influences have resulted in population declines and range reduction of freshwater biodiversity worldwide. Conservation of biodiversity is complicated by the landscape position of rivers and wetlands as 'receivers' of land-use effluents, and the problems posed by endemism and thus non-substitutability. In addition, in many parts of the world, fresh water is subject to severe competition among multiple human stakeholders. Protection of freshwater biodiversity is perhaps the ultimate conservation challenge

  9. Freshwater biodiversity: importance, threats, status and conservation challenges.

    Science.gov (United States)

    Dudgeon, David; Arthington, Angela H; Gessner, Mark O; Kawabata, Zen-Ichiro; Knowler, Duncan J; Lévêque, Christian; Naiman, Robert J; Prieur-Richard, Anne-Hélène; Soto, Doris; Stiassny, Melanie L J; Sullivan, Caroline A

    2006-05-01

    Freshwater biodiversity is the over-riding conservation priority during the International Decade for Action - 'Water for Life' - 2005 to 2015. Fresh water makes up only 0.01% of the World's water and approximately 0.8% of the Earth's surface, yet this tiny fraction of global water supports at least 100000 species out of approximately 1.8 million - almost 6% of all described species. Inland waters and freshwater biodiversity constitute a valuable natural resource, in economic, cultural, aesthetic, scientific and educational terms. Their conservation and management are critical to the interests of all humans, nations and governments. Yet this precious heritage is in crisis. Fresh waters are experiencing declines in biodiversity far greater than those in the most affected terrestrial ecosystems, and if trends in human demands for water remain unaltered and species losses continue at current rates, the opportunity to conserve much of the remaining biodiversity in fresh water will vanish before the 'Water for Life' decade ends in 2015. Why is this so, and what is being done about it? This article explores the special features of freshwater habitats and the biodiversity they support that makes them especially vulnerable to human activities. We document threats to global freshwater biodiversity under five headings: overexploitation; water pollution; flow modification; destruction or degradation of habitat; and invasion by exotic species. Their combined and interacting influences have resulted in population declines and range reduction of freshwater biodiversity worldwide. Conservation of biodiversity is complicated by the landscape position of rivers and wetlands as 'receivers' of land-use effluents, and the problems posed by endemism and thus non-substitutability. In addition, in many parts of the world, fresh water is subject to severe competition among multiple human stakeholders. Protection of freshwater biodiversity is perhaps the ultimate conservation challenge

  10. Improved Multispanning Tree Routing Using Efficient and Reliable Routing Algorithm for Irregular Networks

    Directory of Open Access Journals (Sweden)

    L. Keerthana

    2012-06-01

    Full Text Available A Strategy of Multispanning Tree Zone Ordered Label Based routing is improved with Efficient and Reliable (EAR routing for irregular networks is presented and analyzed in this work. Most existing deadlock free routing methods for irregular topologies impose several limitations on node and channel labeling in an irregular network is based on a pre-defined spanning tree.It is not possible to form a deadlock free zone of three or four channel labels for two spanning tree. So this existing Multispanning Tree Zone Ordered Label Based routing is modified with Efficient and Reliable (EAR routing. EAR is based on four parameters length of the path,distance traversed,transmission of link and energy levels to dynamically determine and maintain the best routes.. The simulation results have shown highest packet delivery ratio, minimum latency, and energy consumption.

  11. Malacofauna of Holocene freshwater calcareous deposits of Lithuania

    Science.gov (United States)

    Sanko, Aleksander; Vainorius, Julius; Melešytė, Monika

    2010-12-01

    The malacofauna of freshwater calcareous deposits of Lithuania was studied. Sections of the Mūšos Tyrelis and Pabaliai peatbogs near the town of Šiauliai, as well as Dubičiai section (three sites) in SE Lithuania and Dūkštos in Central Lithuania were investigated. Freshwater calcareous deposits are attributed to three groups of facies - lacustrine, valley-hollow-peatbog and terrestrial. Each group of facies consists of sub-facies (freshwater lime, "gazha" (limno-calcite), peat-tufa, calcareous tufa, "mada") varying the formation conditions, composition and other characteristics. The mollusc fauna in the lacustrine facies group (Mūšos Tyrelis and Pabaliai sections) is represented by lacustrine species containing euryecological freshwater molluscs. Terrestrial and rheophilous species are rare or absent in the lacustrine group. Deposits of valley-hollow-peatbog facies contain shells of euryecological freshwater and lacustrine molluscs together with rheophyl shells, sometimes with abundant terrestrial shells, as was observed in the Dubičiai-4 section. A characteristic feature of the terrestrial facies group deposits is the occurrence of solely terrestrial mollusc shells (Dūkštos section).

  12. Taking High Conservation Value from Forests to Freshwaters

    Science.gov (United States)

    Abell, Robin; Morgan, Siân K.; Morgan, Alexis J.

    2015-07-01

    The high conservation value (HCV) concept, originally developed by the Forest Stewardship Council, has been widely incorporated outside the forestry sector into companies' supply chain assessments and responsible purchasing policies, financial institutions' investment policies, and numerous voluntary commodity standards. Many, if not most, of these newer applications relate to production practices that are likely to affect freshwater systems directly or indirectly, yet there is little guidance as to whether or how HCV can be applied to water bodies. We focus this paper on commodity standards and begin by exploring how prominent standards currently address both HCVs and freshwaters. We then highlight freshwater features of high conservation importance and examine how well those features are captured by the existing HCV framework. We propose a new set of freshwater `elements' for each of the six values and suggest an approach for identifying HCV Areas that takes out-of-fence line impacts into account, thereby spatially extending the scope of existing methods to define HCVs. We argue that virtually any non-marine HCV assessment, regardless of the production sector, should be expanded to include freshwater values, and we suggest how to put those recommendations into practice.

  13. Bistability of mangrove forests and competition with freshwater plants

    Science.gov (United States)

    Jiang, Jiang; Fuller, Douglas O; Teh, Su Yean; Zhai, Lu; Koh, Hock Lye; DeAngelis, Donald L.; Sternberg, L.D.S.L.

    2015-01-01

    Halophytic communities such as mangrove forests and buttonwood hammocks tend to border freshwater plant communities as sharp ecotones. Most studies attribute this purely to underlying physical templates, such as groundwater salinity gradients caused by tidal flux and topography. However, a few recent studies hypothesize that self-reinforcing feedback between vegetation and vadose zone salinity are also involved and create a bistable situation in which either halophytic dominated habitat or freshwater plant communities may dominate as alternative stable states. Here, we revisit the bistability hypothesis and demonstrate the mechanisms that result in bistability. We demonstrate with remote sensing imagery the sharp boundaries between freshwater hardwood hammock communities in southern Florida and halophytic communities such as buttonwood hammocks and mangroves. We further document from the literature how transpiration of mangroves and freshwater plants respond differently to vadose zone salinity, thus altering the salinity through feedback. Using mathematical models, we show how the self-reinforcing feedback, together with physical template, controls the ecotones between halophytic and freshwater communities. Regions of bistability along environmental gradients of salinity have the potential for large-scale vegetation shifts following pulse disturbances such as hurricane tidal surges in Florida, or tsunamis in other regions. The size of the region of bistability can be large for low-lying coastal habitat due to the saline water table, which extends inland due to salinity intrusion. We suggest coupling ecological and hydrologic processes as a framework for future studies.

  14. Information Priority Based Multicast Routing in MANETs

    Directory of Open Access Journals (Sweden)

    Rajashekhar

    2011-07-01

    Full Text Available The routing efficiency in Mobile Ad Hoc Networks (MANETs suffers from frequent batterydrains, mobility and large variation of received signal strength. Thus, nodes and links in MANETsbecome more vulnerable and unstable. Multicast routing in MANETs for group communication requiresestablishment of reliable links between neighbouring nodes called as reliability pair beginning from thesource and extending such reliability pairs enroute to the destination. If there are multiple paths fromsource to every multicast destination, the reliability of source information may be enhanced by sendinghigher priority information on higher priority path.In this paper, we propose a scheme of Information Priority based Multicast Routing in MANETsusing multiple paths (IPMRM. IPMRM operates in following phases. (1 Reliability pair factorcomputation based on node power level, received differential signal strength between the nodes andmobility. (2 Pruning neighbor nodes that have reliability pair factor lesser than a threshold. (3 Findingmulticast mesh routes with multiple paths to a destination using request and reply packets. (4 Priorityassignment to multiple paths based on minimum value of reliability pair factor of a path and informationtransfer from source to multicast destination. (4 Route maintenance against link failures. The simulationresults for packet delivery ratio and control overhead demonstrate better performance of IPMRM overOn Demand Multicast Routing Protocol (ODMRP and Enhanced ODMRP (EODMRP.

  15. Multirate Anypath Routing in Wireless Mesh Networks

    CERN Document Server

    Laufer, Rafael

    2008-01-01

    In this paper, we present a new routing paradigm that generalizes opportunistic routing in wireless mesh networks. In multirate anypath routing, each node uses both a set of next hops and a selected transmission rate to reach a destination. Using this rate, a packet is broadcast to the nodes in the set and one of them forwards the packet on to the destination. To date, there is no theory capable of jointly optimizing both the set of next hops and the transmission rate used by each node. We bridge this gap by introducing a polynomial-time algorithm to this problem and provide the proof of its optimality. The proposed algorithm runs in the same running time as regular shortest-path algorithms and is therefore suitable for deployment in link-state routing protocols. We conducted experiments in a 802.11b testbed network, and our results show that multirate anypath routing performs on average 80% and up to 6.4 times better than anypath routing with a fixed rate of 11 Mbps. If the rate is fixed at 1 Mbps instead, p...

  16. Survivable Lightpath Routing in WDM Optical Networks

    Institute of Scientific and Technical Information of China (English)

    LIUFengqing; ZENGQingji; ZHUXu; YANGXudong; XIAOShilin

    2004-01-01

    In IP over WDM networks, when a failure(such as a fiber cut) occurs, the service restoration can be implemented by dynamic routing in IP layer. But it needs that the logical topology remains connected after any physical link failure. Otherwise, IP layer cannot find an alternate path to restore the service. The problem of routing logical links (lightpaths) on a physical network topology in a way that the logical topology remains connected in the event of single physical link failure is called survivabl erouting. In this paper~ we address the survivable routing problem by proposing a new ILP algorithm that works well with sparse-connected logical topologies. The necessary and sufficient conditions for survivable routing are simplified, which greatly reduces the number of survivable constraints. Based-on the simplified conditions, a new ILP formulation with K-shortest paths as alternate paths for a logical link is presented, which mainly reduces the number of ILP variables. Finally, numerical results are given and discussed to show that most survivable routing solutions can be found with our algorithms, and the time needed to find such a survivable routing solution is much smaller than other similar methods.

  17. The Route Analysis Based On Flight Plan

    Science.gov (United States)

    Feriyanto, Nur; Saleh, Chairul; Fauzi, Achmad; Rachman Dzakiyullah, Nur; Riza Iwaputra, Kahfi

    2016-02-01

    Economic development effects use of air transportation since the business process in every aspect was increased. Many people these days was prefer using airplane because it can save time and money. This situation also effects flight routes, many airlines offer new routes to deal with competition. Managing flight routes is one of the problems that must be faced in order to find the efficient and effective routes. This paper investigates the best routes based on flight performance by determining the amount of block fuel for the Jakarta-Denpasar flight route. Moreover, in this work compares a two kinds of aircraft and tracks by calculating flight distance, flight time and block fuel. The result shows Jakarta-Denpasar in the Track II has effective and efficient block fuel that can be performed by Airbus 320-200 aircraft. This study can contribute to practice in making an effective decision, especially helping executive management of company due to selecting appropriate aircraft and the track in the flight plan based on the block fuel consumption for business operation.

  18. Manet Load Balancing Parallel Routing Protocol

    Directory of Open Access Journals (Sweden)

    Hesham Arafat Ali

    2012-07-01

    Full Text Available In recent years, multi-path routing protocols have attained more attention in mobile ad hoc networks as compared to other routing schemes due to their abilities and efficiency in improving bandwidth of communication, increasing delivery reliability, responding to congestion and heavy traffic. Several protocols have been developed to address multi path routing, but it always has a problem that the discovered paths may be not 100% disjoint and sending data is done in only one path until it's broken; the discovery of multiple paths also generates more overhead on the network. Load Balancing Parallel Routing Protocol [LBPRP] tried to solve previous multi path problems, distributing traffic among multiple paths sending data in parallel form as it uses all paths in the same time. We employed a simple test scenario to be sure of proposed model efficiency and to validate the proposed Load Balancing Parallel Routing Protocol. [LBPRP] will achieve load balancing in sending data, decreasing the end-to-end delay and increasing the packet delivery ratio and throughput, thus the performance of multi-path routing protocols can be improved consequently.

  19. ACO Agent Based Routing in AOMDV Environment

    Directory of Open Access Journals (Sweden)

    Kaur Amanpreet

    2016-01-01

    Full Text Available Mobile Ad-hoc Network (MANET is a group of moving nodes which can communicate with each other without the help of any central stationary node. All the nodes in the MANET act as router for forwarding data packets. The nodes in the network also move randomly and there exists no fixed infrastructure. So, path breaks are the frequent problem in MANET. The routing protocol faces a lot of problem due these path breaks. Therefore, the routing protocol which is multipath in nature is more reliable than a unipath routing protocol. Ant colony optimization is a relatively new technique which is suitable for the optimization problems. AOMDV is a multipath routing protocol. Thus, if there happens to be path break, the packets can start following the new path which has already been selected. In this paper, we are trying to add ant’s agents into AOMDV behavior. In this way, the new protocol will be benefited by the dual properties i.e. of ant’s nature and multipath nature of AOMDV. The modified concept is simulated and the outcomes are compared with AOMDV, AODV and DSR routing protocols for few performance parameters. Results obtained are encouraging; the new algorithm performs better than traditional unipath and multipath routing protocols.

  20. The Great Migration and African-American Genomic Diversity.

    Directory of Open Access Journals (Sweden)

    Soheil Baharian

    2016-05-01

    Full Text Available We present a comprehensive assessment of genomic diversity in the African-American population by studying three genotyped cohorts comprising 3,726 African-Americans from across the United States that provide a representative description of the population across all US states and socioeconomic status. An estimated 82.1% of ancestors to African-Americans lived in Africa prior to the advent of transatlantic travel, 16.7% in Europe, and 1.2% in the Americas, with increased African ancestry in the southern United States compared to the North and West. Combining demographic models of ancestry and those of relatedness suggests that admixture occurred predominantly in the South prior to the Civil War and that ancestry-biased migration is responsible for regional differences in ancestry. We find that recent migrations also caused a strong increase in genetic relatedness among geographically distant African-Americans. Long-range relatedness among African-Americans and between African-Americans and European-Americans thus track north- and west-bound migration routes followed during the Great Migration of the twentieth century. By contrast, short-range relatedness patterns suggest comparable mobility of ∼15-16km per generation for African-Americans and European-Americans, as estimated using a novel analytical model of isolation-by-distance.

  1. Pseudo-Cycle-Based Multicast Routing in Wormhole-Routed Networks

    Institute of Scientific and Technical Information of China (English)

    SONG JianPing (宋建平); HOU ZiFeng (侯紫峰); XU Ming (许铭)

    2003-01-01

    This paper addresses the problem of fault-tolerant multicast routing in wormholerouted multicomputers. A new pseudo-cycle-based routing method is presented for constructing deadlock-free multicast routing algorithms. With at most two virtual channels this technique can be applied to any connected networks with arbitrary topologies. Simulation results show that this technique results in negligible performance degradation even in the presence of a large number of faulty nodes.

  2. Are GIS-modelled routes a useful proxy for the actual routes followed by commuters?

    OpenAIRE

    Dalton, Alice M; Jones, Andrew P.; Panter, Jenna; Ogilvie, David

    2014-01-01

    Active commuting offers the potential to increase physical activity among adults by being built into daily routines. Characteristics of the route to work may influence propensity to walk or cycle. Geographic information system (GIS) software is often used to explore this by modelling routes between home and work. However, if the validity of modelled routes depends on the mode of travel used, studies of environmental determinants of travel may be biased. We aimed to understand how well mod...

  3. Asian American-Pacific American Relations: The Asian American Perspective.

    Science.gov (United States)

    Chan, Sucheng

    This paper examines the migration and settlement history of Asians into the United States and the interaction of the major Asian immigrants with each other and with American society. An important thesis is that, because the differences between Asian Americans and Pacific Islanders are much greater than the similarities between them, they should no…

  4. Assessing and managing freshwater ecosystems vulnerable to global change

    Science.gov (United States)

    Angeler, David G.; Allen, Craig R.; Birge, Hannah E.; Drakare, Stina; McKie, Brendan G.; Johnson, Richard K.

    2014-01-01

    Freshwater ecosystems are important for global biodiversity and provide essential ecosystem services. There is consensus in the scientific literature that freshwater ecosystems are vulnerable to the impacts of environmental change, which may trigger irreversible regime shifts upon which biodiversity and ecosystem services may be lost. There are profound uncertainties regarding the management and assessment of the vulnerability of freshwater ecosystems to environmental change. Quantitative approaches are needed to reduce this uncertainty. We describe available statistical and modeling approaches along with case studies that demonstrate how resilience theory can be applied to aid decision-making in natural resources management. We highlight especially how long-term monitoring efforts combined with ecological theory can provide a novel nexus between ecological impact assessment and management, and the quantification of systemic vulnerability and thus the resilience of ecosystems to environmental change.

  5. Challenges of Freshwater Fisheries in Nepal: A Short Overview

    Directory of Open Access Journals (Sweden)

    Nawaraj Gautam

    2015-12-01

    Full Text Available Abundant freshwater resources originated from Himalayas and high geographical variations in Nepal are two factors which might be positive benefits to improve the aquaculture in land locked country. Low labor cost is also another plus point to get better management in fisheries sector. Freshwater fisheries in Nepal are mostly dominated by catch up fisheries of indigenous fish species available in rivers, lakes and paddy fields but exotic and sophisticated species been also introduced in small scales. Beside these, poly cultural pond fish farming is most viable. Carp fishes are the major species and uncontrolled unmanaged capture fisheries dominants over systematic aquaculture. Poor technological implementations, poor budgetary plan, not proper management strategies, lack of quality fish feed and fingerlins, lower market availability are some of the major challenges of Nepalese freshwater fisheries. Long-term sustainable plan, scientific and technological study on indigenous fish species, proper hygiene management and better disease control might improve the current aquaculture status of Nepal.

  6. New data on freshwater psammic Gastrotricha from Brazil

    Directory of Open Access Journals (Sweden)

    André Rinaldo Garraffoni

    2010-10-01

    Full Text Available Current knowledge of freshwater gastrotrich fauna from Brazil is underestimated as only two studies are available. The present communication is a taxonomic account of the first-ever survey of freshwater Gastrotricha in Minas Gerais State. Samplings were carried out yielding six species of three Chaetonotidae genera: Aspidiophorus cf. pleustonicus, Ichthydium cf. chaetiferum, Chaetonotus acanthocephalus, C. heideri, C. cf. succinctus, Chaetonotus sp., and also an undescribed species belonging to the genus Redudasys (incertae sedis: this is the first finding of specimens of Redudasys outside of original type locality. These preliminary observations suggest that the knowledge of the biodiversity of Gastrotricha in the Minas Gerais State, as well as in the whole Brazil, will certainly increase as further investigations are undertaken, and that freshwater Macrodasyida may be more common than previously thought.

  7. Evaluating Alternative Strategies for Investments in Freshwater Conservation

    Science.gov (United States)

    Cheruvelil, K. S.; Kramer, D. B.; Zhang, T.; Ligmann-Zielinska, A.; Soranno, P.; Bremigan, M. T.

    2012-12-01

    Efforts towards systematic conservation planning for freshwaters have progressed far less than similar efforts in the terrestrial and marine environments. Although there are differences in the coupled human and natural systems that distinguish freshwater, terrestrial, and marine environments, many of the tools that have been used in terrestrial and marine systems can also be used for conservation planning for freshwater resources. In this paper, we used one such tool, return on investment (ROI), to identify optimal conservation portfolios. Our overarching research question is: how do different strategies for evaluating ROI benefits influence the resulting portfolio and the outcome of interest - in our case, water quality? Specifically, we examined investments to convert farmed agricultural land to fallow land to improve water quality in 55 inland lakes in southwestern Michigan. We simulated investments and compared the ROIs for the following strategies: 1) economic; 2) ecological; 3) environmental policy and 4) agricultural policy. We also tested the well-established assumption that riparian lands, those abutting and within 30 m of freshwater shorelines, have the greatest potential to influence water quality. We found that 1) investments in freshwater resources through the conservation of riparian land are more effective than the conservation of randomly selected parcels of similar land area in the catchment; 2) the costs and benefits of riparian land conservation vary considerably among lakes; 3) the choice of investment strategies results in very different conservation portfolios; 4) the resulting conservation portfolios have very different distributional and policy implications. These analyses and results provide a foundation on which to improve systematic conservation planning for freshwaters.

  8. 2H and 18O Freshwater Isoscapes of Scotland

    Science.gov (United States)

    Meier-Augenstein, Wolfram; Hoogewerff, Jurian; Kemp, Helen; Frew, Danny

    2013-04-01

    Scotland's freshwater lochs and reservoirs provide a vital resource for sustaining biodiversity, agriculture, food production as well as for human consumption. Regular monitoring of freshwaters by the Scottish Environment Protection Agency (SEPA) fulfils legislative requirements with regards to water quality but new scientific methods involving stable isotope analysis present an opportunity combining these mandatory monitoring schemes with fundamental research to inform and deliver on current and nascent government policies [1] through gaining a greater understanding of Scottish waters and their importance in the context of climate change, environmental sustainability and food security. For example, 2H and 18O isoscapes of Scottish freshwater could be used to underpin research and its applications in: • Climate change - Using longitudinal changes in the characteristic isotope composition of freshwater lochs and reservoirs as proxy, isoscapes will provide a means to assess if and how changes in temperature and weather patterns might impact on precipitation patterns and amount. • Scottish branding - Location specific stable isotope signatures of Scottish freshwater have the potential to be used as a tool for provenancing and thus protecting premium Scottish produce such as Scottish beef, Scottish soft fruit and Scottish Whisky. During 2011 and 2012, with the support of SEPA more than 110 samples from freshwater lochs and reservoirs were collected from 127 different locations across Scotland including the Highlands and Islands. Here we present the results of this sampling and analysis exercise isotope analyses in form of 2H and 18O isoscapes with an unprecedented grid resolution of 26.5 × 26.5 km (or 16.4 × 16.4 miles). [1] Adaptation Framework - Adapting Our Ways: Managing Scotland's Climate Risk (2009): Scotland's Biodiversity: It's in Your Hands - A strategy for the conservation and enhancement of biodiversity in Scotland (2005); Recipe For Success - Scotland

  9. Patterns of Freshwater Species Richness, Endemism, and Vulnerability in California.

    Directory of Open Access Journals (Sweden)

    Jeanette K Howard

    Full Text Available The ranges and abundances of species that depend on freshwater habitats are declining worldwide. Efforts to counteract those trends are often hampered by a lack of information about species distribution and conservation status and are often strongly biased toward a few well-studied groups. We identified the 3,906 vascular plants, macroinvertebrates, and vertebrates native to California, USA, that depend on fresh water for at least one stage of their life history. We evaluated the conservation status for these taxa using existing government and non-governmental organization assessments (e.g., endangered species act, NatureServe, created a spatial database of locality observations or distribution information from ~400 data sources, and mapped patterns of richness, endemism, and vulnerability. Although nearly half of all taxa with conservation status (n = 1,939 are vulnerable to extinction, only 114 (6% of those vulnerable taxa have a legal mandate for protection in the form of formal inclusion on a state or federal endangered species list. Endemic taxa are at greater risk than non-endemics, with 90% of the 927 endemic taxa vulnerable to extinction. Records with spatial data were available for a total of 2,276 species (61%. The patterns of species richness differ depending on the taxonomic group analyzed, but are similar across taxonomic level. No particular taxonomic group represents an umbrella for all species, but hotspots of high richness for listed species cover 40% of the hotspots for all other species and 58% of the hotspots for vulnerable freshwater species. By mapping freshwater species hotspots we show locations that represent the top priority for conservation action in the state. This study identifies opportunities to fill gaps in the evaluation of conservation status for freshwater taxa in California, to address the lack of occurrence information for nearly 40% of freshwater taxa and nearly 40% of watersheds in the state, and to

  10. A new polystomatid (Monogenea, Polystomatidae) from the mouth of the North American freshwater turtle Pseudemys nelsoni.

    Science.gov (United States)

    Du Preez, Louis H; Van Rooyen, Michelle

    2015-01-01

    Based on material collected from Pseudemys nelsoni (Reptilia: Chelonia: Emydidae) during a parasite survey of the herpetofauna around Gainesville, Florida, USA, Polystomoides nelsoni sp. n. is described as a new polystome species. This parasite was found in the oral and pharyngeal region of the host. In a sample of nine Pseudemys nelsoni, three specimens were found to release polystome eggs. One turtle was euthanized and dissected and found to be infected in the oral region with 19 specimens belonging to an as-yet-unknown Polystomoides. This is only the fifth Polystomoides recorded from the Nearctic realm. This species is distinguished from known species by a combination of characteristics including marginal hooklet morphology, body length and haptor dimensions. PMID:26798243

  11. RECOVERY OF FRESHWATER STORED IN SALINE AQUIFERS IN PENINSULAR FLORIDA.

    Science.gov (United States)

    Merritt, Michael L.

    1986-01-01

    Subsurface freshwater storage has been operationally tested at seven sites in central and south Florida. Injection was into a high chloride water aquifer at six sites, and into a high sulfate water aquifer at the seventh. Recovery efficiency has ranged from 0 to 75 percent in high chloride water aquifers, and has exceeded 100 percent in the high sulfate water aquifer. Computer modeling techniques were used to examine the geohydrologic, design, and management factors governing the recovery efficiency of subsurface freshwater storage. The modeling approach permitted many combinations of geohydrologic and operational conditions to be studied at relatively low cost.

  12. Alternative routes to olefins. Chances and challenges

    Energy Technology Data Exchange (ETDEWEB)

    Meiswinkel, A.; Delhomme, C.; Ponceau, M. [Linde AG, Pullach (Germany)

    2013-11-01

    In the future, conventional raw materials which are used for the production of olefins will get shorter and more expensive and alternative raw materials and production routes will gain importance. Natural gas, coal, shale oil or bio-mass are potential sources for the production of olefins, especially ethylene and propylene, as major base chemicals. Several potential production routes were already developed in the past, but cost, energy and environmental considerations might make these unattractive or unfeasible in comparison to traditional processes (e.g. steam cracking). Other processes such as methanol to olefins processes were successfully developed and first commercial units are running. In addition, combination of traditional processes (e.g. coal/biomass gasification, Fischer-Tropsch and steam cracking) might enable new pathways. Besides, dehydration of ethanol is opening direct routes from biomass to 'green' ethylene. However, for these 'bio-routes', feedstock availability and potential land use conflict with food production (sugar cane, wheat,..) still need to be evaluated. finally, new oxidative routes, including processes such as oxidative coupling of methane or oxidative dehydrogenation, are still at an early development stage but present potential for future industrial applications. (orig.) (Published in summary form only)

  13. Fuzzy Optimized Metric for Adaptive Network Routing

    Directory of Open Access Journals (Sweden)

    Ahmad Khader Haboush

    2012-04-01

    Full Text Available Network routing algorithms used today calculate least cost (shortest paths between nodes. The cost of a path is the sum of the cost of all links on that path. The use of a single metric for adaptive routing is insufficient to reflect the actual state of the link. In general, there is a limitation on the accuracy of the link state information obtained by the routing protocol. Hence it becomes useful if two or more metrics can be associated to produce a single metric that can describe the state of the link more accurately. In this paper, a fuzzy inference rule base is implemented to generate the fuzzy cost of each candidate path to be used in routing the incoming calls. This fuzzy cost is based on the crisp values of the different metrics; a fuzzy membership function is defined. The parameters of these membership functions reflect dynamically the requirement of the incoming traffic service as well as the current state of the links in the path. And this paper investigates how three metrics, the mean link bandwidth, queue utilization and the mean link delay, can be related using a simple fuzzy logic algorithm to produce a optimized cost of the link for a certain interval that is more „precise‟ than either of the single metric, to solve routing problem .

  14. Routing algorithms in networks-on-chip

    CERN Document Server

    Daneshtalab, Masoud

    2014-01-01

    This book provides a single-source reference to routing algorithms for Networks-on-Chip (NoCs), as well as in-depth discussions of advanced solutions applied to current and next generation, many core NoC-based Systems-on-Chip (SoCs). After a basic introduction to the NoC design paradigm and architectures, routing algorithms for NoC architectures are presented and discussed at all abstraction levels, from the algorithmic level to actual implementation.  Coverage emphasizes the role played by the routing algorithm and is organized around key problems affecting current and next generation, many-core SoCs. A selection of routing algorithms is included, specifically designed to address key issues faced by designers in the ultra-deep sub-micron (UDSM) era, including performance improvement, power, energy, and thermal issues, fault tolerance and reliability.   ·         Provides a comprehensive overview of routing algorithms for Networks-on-Chip and NoC-based, manycore systems; ·         Describe...

  15. Low Carbon Footprint Routes for Bird Watching

    Directory of Open Access Journals (Sweden)

    Wei-Ta Fang

    2015-03-01

    Full Text Available Bird watching is one of many recreational activities popular in ecotourism. Its popularity, therefore, prompts the need for studies on energy conservation. One such environmentally friendly approach toward minimizing bird watching’s ecological impact is ensuring a reduced carbon footprint by using an economic travel itinerary comprising a series of connected routes between tourist attractions that minimizes transit time. This study used a travel-route planning approach using geographic information systems to detect the shortest path, thereby solving the problems associated with time-consuming transport. Based on the results of road network analyses, optimal travel-route planning can be determined. These methods include simulated annealing (SA and genetic algorithms (GA. We applied two algorithms in our simulation research to detect which one is an appropriate algorithm for running carbon-routing algorithms at the regional scale. SA, which is superior to GA, is considered an excellent approach to search for the optimal path to reduce carbon dioxide and high gasoline fees, thereby controlling travel time by using the shortest travel routes.

  16. An Indirect Route for Ethanol Production

    Energy Technology Data Exchange (ETDEWEB)

    Eggeman, T.; Verser, D.; Weber, E.

    2005-04-29

    The ZeaChem indirect method is a radically new approach to producing fuel ethanol from renewable resources. Sugar and syngas processing platforms are combined in a novel way that allows all fractions of biomass feedstocks (e.g. carbohydrates, lignins, etc.) to contribute their energy directly into the ethanol product via fermentation and hydrogen based chemical process technologies. The goals of this project were: (1) Collect engineering data necessary for scale-up of the indirect route for ethanol production, and (2) Produce process and economic models to guide the development effort. Both goals were successfully accomplished. The projected economics of the Base Case developed in this work are comparable to today's corn based ethanol technology. Sensitivity analysis shows that significant improvements in economics for the indirect route would result if a biomass feedstock rather that starch hydrolyzate were used as the carbohydrate source. The energy ratio, defined as the ratio of green energy produced divided by the amount of fossil energy consumed, is projected to be 3.11 to 12.32 for the indirect route depending upon the details of implementation. Conventional technology has an energy ratio of 1.34, thus the indirect route will have a significant environmental advantage over today's technology. Energy savings of 7.48 trillion Btu/yr will result when 100 MMgal/yr (neat) of ethanol capacity via the indirect route is placed on-line by the year 2010.

  17. Eccentricity in Zone Routing Protocol for MANET

    Directory of Open Access Journals (Sweden)

    Mrs Komal Nair

    2012-06-01

    Full Text Available A Mobile Ad-Hoc Network (MANET is a decentralized network of autonomous mobile nodes, able to communicate with each other over wireless links. Due to the mobility of the nodes, the topology ofthe network changes spontaneously, therefore use of conventional routing tables maintained at fixed points (routers is not suggested. Such a network may operate in a standalone fashion. There are variousrouting protocols available for MANETs. The most popular ones are DSR, DSDV and ZRP .The zone routing protocol (ZRP is a hybrid routing protocol that proactively maintains routes within a localregion of the network. ZRP can be configured for a particular network through adjustment of a single parameter, the routing zone radius. In this paper, we address the issue of configuring the ZRP to providethe best performance for a particular network at any time with the concept of eccentricity. The results illustrate the important characteristics of different protocols based on their performance and thus suggest some improvements in the respective protocol. The tools used for the simulation are NS2 which is the main simulator, NAM (Network Animator and Tracegraph which is used for preparing the graphs from the trace files.

  18. Incidence of the leech Actinobdella pediculata on freshwater drum in Lake Erie

    Science.gov (United States)

    Bur, Michael T.

    1994-01-01

    Actinobdella pediculata (Glossiphoniidae), a freshwater leech, was found attached to freshwater drum (Aplodinotus grunniens) from western Lake Erie during 1991 through 1993. The animal was first observed during routine examinations of freshwater drum collected in May 1991. The leeches were usually attached to the inside, lower portion of the opercula near the isthmus. Incidence of attachment increased with freshwater drum age and length. No noticeable adverse effects on the fish from attachment by the leech were noted.

  19. Understanding the regulation of estivation in a freshwater snail through iTRAQ-based comparative proteomics

    KAUST Repository

    Sun, Jin

    2013-11-01

    The apple snail Pomacea canaliculata is a freshwater gastropod with a remarkable ability to withstand seasonal or unpredictable dry conditions by entering estivation. Studies of P. canaliculata using conventional biochemical and the individual gene approaches have revealed the expressional changes of several enzymes and antioxidative genes in response to estivation and arousal. In this study, we applied iTRAQ-coupled two-dimensional LC-MS/MS to identify and quantify the global protein expression during the estivation and arousal of P. canaliculata. A total of 1040 proteins were identified, among which 701 proteins were quantified and compared across four treatments (i.e., control, active snails; short-term estivation, 3 days of exposure to air; prolonged estivation, 30 days of exposure to air; and arousal, 6 h after resubmergence in water) revealing 53 differentially expressed proteins. A comparison of protein expression profiles across treatments indicated that the proteome of this species was very insensitive to initial estivation, with only 9 proteins differentially expressed as compared with the control. Among the 9 proteins, the up-regulations of two immune related proteins indicated the initial immune response to the detection of stress cues. Prolonged estivation resulted in many more differentially expressed proteins (47 compared with short-term estivation treatment), among which 16 were down-regulated and 31 were up-regulated. These differentially expressed proteins have provided the first global picture of a shift in energy usage from glucose to lipid, prevention of protein degradation and elevation of oxidative defense, and production of purine for uric acid production to remove toxic ammonia during prolonged estivation in a freshwater snail. From prolonged estivation to arousal, only 6 proteins changed their expression level, indicating that access to water and food alone is not a necessary condition to reactivate whole-sale protein expression. A

  20. Juvenile salmonid use of freshwater emergent wetlands in the floodplain and its implications for conservation management

    Science.gov (United States)

    Henning, J.A.; Gresswell, R.E.; Fleming, I.A.

    2006-01-01

    A recent trend of enhancing freshwater emergent wetlands for waterfowl and other wildlife has raised concern about the effects of such measures on juvenile salmonids. We undertook this study to quantify the degree and extent of juvenile Pacific salmon Oncorhynchus spp. utilization of enhanced and unenhanced emergent wetlands within the floodplain of the lower Chehalis River, Washington, and to determine the fate of the salmon using them. Enhanced emergent wetlands contained water control structures that provided an outlet for fish emigration and a longer hydroperiod for rearing than unenhanced wetlands. Age-0 and age-1 coho salmon O. kisutch were the most common salmonid at all sites, enhanced wetlands having significantly higher age-1 abundance than unenhanced wetlands that were a similar distance from the main-stem river. Yearling coho salmon benefited from rearing in two enhanced wetland habitats, where their specific growth rate and minimum estimates of survival (1.43%/d by weight and 30%; 1.37%/d and 57%) were comparable to those in other side-channel rearing studies. Dissolved oxygen concentrations decreased in emergent wetlands throughout the season and approached the limits lethal to juvenile salmon by May or June each year. Emigration patterns suggested that age-0 and age-1 coho salmon emigrated as habitat conditions declined. This observation was further supported by the results of an experimental release of coho salmon. Survival of fish utilizing emergent wetlands was dependent on movement to the river before water quality decreased or stranding occurred from wetland desiccation. Thus, our results suggest that enhancing freshwater wetlands via water control structures can benefit juvenile salmonids, at least in the short term, by providing conditions for greater growth, survival, and emigration. ?? Copyright by the American Fisheries Society 2006.

  1. ACRR: Ad Hoc On-Demand Distance Vector Routing with Controlled Route Requests

    CERN Document Server

    Kataria, Jayesh; Sanyal, Sugata

    2010-01-01

    Reactive routing protocols like Ad Hoc On-Demand Distance Vector Routing (AODV) and Dynamic Source Routing (DSR)in Ad-Hoc Wireless Networks which are used in Mobile and Ad Hoc Networks (MANETs) work by flooding the network with control packets. There is generally a limit on the number of these packets that can be generated or forwarded. But a malicious node can disregard this limit and flood the network with fake control packets. These packets hog the limited bandwidth and processing power of genuine nodes in the network while being forwarded. Due to this, genuine route requests suffer and many routes either do not get a chance to materialize or they end up being longer than otherwise. In this paper we propose a non cryptographic solution to the above problem and prove its efficiency by means of simulation.

  2. Research on secure routing algorithm in wireless sensor network

    Science.gov (United States)

    Zhang, Bo

    2013-03-01

    Through the research on the existing wireless sensor network (WSN) and its security technologies, this paper presents a design of the WSN-based secure routing algorithm. This design uses the existing routing algorithm as chief source, adding the security guidance strategy, introducing the location key information, to enhance the security performance of WSN routing. The improved routing algorithm makes the WSN routing achieve better anti-attack in the case of little overhead increase, therefore has high practical value.

  3. MAP: Medial axis based geometric routing in sensor networks

    OpenAIRE

    Bruck, Jehoshua; Gao, Jie; Jiang, Anxiao

    2007-01-01

    One of the challenging tasks in the deployment of dense wireless networks (like sensor networks) is in devising a routing scheme for node to node communication. Important consideration includes scalability, routing complexity, quality of communication paths and the load sharing of the routes. In this paper, we show that a compact and expressive abstraction of network connectivity by the medial axis enables efficient and localized routing. We propose MAP, a Medial Axis based naming and routing...

  4. Routing Security in Mobile Ad-hoc Networks

    OpenAIRE

    Karlsson, Jonny; Dooley, Laurence S.; Pulkkis, Goran

    2012-01-01

    The role of infrastructure-less mobile ad hoc networks (MANETs) in ubiquitous networks is outlined. In a MANET there are no dedicated routers and all network nodes must contribute to routing. Classification of routing protocols for MANET is based on how routing information is acquired and maintained by mobile nodes and/or on roles of network nodes in a routing. According to the first classification base, MANET routing protocols are proactive, reactive, or hybrid combinations of proactive and ...

  5. Invasion of Nostocales (cyanobacteria) to Subtropical and Temperate Freshwater Lakes - Physiological, Regional, and Global Driving Forces.

    Science.gov (United States)

    Sukenik, Assaf; Hadas, Ora; Kaplan, Aaron; Quesada, Antonio

    2012-01-01

    Similar to the increased number of studies on invasive plants and animals in terrestrial and aquatic ecosystems, many reports were recently published on the invasion of Nostocales (cyanobacteria) to freshwater environments worldwide. Invasion and proliferation of Nostocales in new habitats have the potential to significantly alter the structure of the native community and to modify ecosystem functioning. But most importantly, they influence the water quality due to a variety of toxic compounds that some species produce. Therefore a special attention was given to the invasion and persistence of toxic cyanobacteria in many aquatic ecosystems. Here we summarize the currently published records on the invasion of two Nostocales genera, Cylindrospermopsis and Aphanizomenon, to lakes and water reservoirs in subtropical and temperate zones. These invading species possess traits thought to be common to many invasive organisms: high growth rate, high resource utilization efficiency and overall superior competitive abilities over native species when local conditions vary. Assuming that dispersion routes of cyanobacteria have not been changed much in recent decades, their recent establishment and proliferation in new habitats indicate changes in the environment under which they can exploit their physiological advantage over the native phytoplankton population. In many cases, global warming was identified as the major driving force for the invasion of Nostocales. Due to this uncontrollable trend, invasive Nostocales species are expected to maintain their presence in new habitats and further expand to new environments. In other cases, regional changes in nutrient loads and in biotic conditions were attributed to the invasion events.

  6. Host diversity and latitude drive trematode diversity patterns in the European freshwater fauna

    NARCIS (Netherlands)

    Thieltges, D.W.; Hof, C.; Dehling, D.M.; Brändle, M.; Brändl, R.; Poulin, R.

    2011-01-01

    Aim We investigated the relationship between host and parasite diversity as well as latitudinal gradients in parasite diversity on a continental scale in European freshwater trematodes.
    Location European freshwaters.
    Methods We extracted distributional data for 564 freshwater trematodes across

  7. Lysogenic infection in sub-tropical freshwater cyanobacteria cultures and natural blooms

    NARCIS (Netherlands)

    L.M. Steenhauer; P.C. Pollard; C.P.D. Brussaard; C. Säwström

    2014-01-01

    Lysogeny has been reported for a few freshwater cyanobacteria cultures, but it is unknown how prevalent it is in freshwater cyanobacteria in situ. Here we tested for lysogeny in (a) cultures of eight Australian species of subtropical freshwater cyanobacteria; (b) seven strains of one species: Cylind

  8. Genetic algorithms for the vehicle routing problem

    Science.gov (United States)

    Volna, Eva

    2016-06-01

    The Vehicle Routing Problem (VRP) is one of the most challenging combinatorial optimization tasks. This problem consists in designing the optimal set of routes for fleet of vehicles in order to serve a given set of customers. Evolutionary algorithms are general iterative algorithms for combinatorial optimization. These algorithms have been found to be very effective and robust in solving numerous problems from a wide range of application domains. This problem is known to be NP-hard; hence many heuristic procedures for its solution have been suggested. For such problems it is often desirable to obtain approximate solutions, so they can be found fast enough and are sufficiently accurate for the purpose. In this paper we have performed an experimental study that indicates the suitable use of genetic algorithms for the vehicle routing problem.

  9. Generalized routing protocols for multihop relay networks

    KAUST Repository

    Khan, Fahd Ahmed

    2011-07-01

    Performance of multihop cooperative networks depends on the routing protocols employed. In this paper we propose the last-n-hop selection protocol, the dual path protocol, the forward-backward last-n-hop selection protocol and the forward-backward dual path protocol for the routing of data through multihop relay networks. The average symbol error probability performance of the schemes is analysed by simulations. It is shown that close to optimal performance can be achieved by using the last-n-hop selection protocol and its forward-backward variant. Furthermore we also compute the complexity of the protocols in terms of number of channel state information required and the number of comparisons required for routing the signal through the network. © 2011 IEEE.

  10. Crosstalk-Aware Routing Resource Assignment

    Institute of Scientific and Technical Information of China (English)

    Hai-Long Yao; Yi-Ci Cai; Qiang Zhou; Xian-Long Hong

    2005-01-01

    Crosstalk noise is one of the emerging issues in deep sub-micrometer technology which causes many undesired effects on the circuit performance. In this paper, a Crosstalk-Aware Routing Resource Assignment (CARRA) algorithm is proposed, which integrates the routing layers and tracks to address the crosstalk noise issue during the track/layer assignment stage. The CARRA problem is formulated as a weighted bipartite matching problem and solved using the linear assignment algorithm. The crosstalk risks between nets are represented by an undirected graph and the maximum number of the concurrent crosstalk risking nets is computed as the max clique of the graph. Then the nets in each max clique are assigned to disadjacent tracks. Thus the crosstalk noise can be avoided based on the clique concept. The algorithm is tested on IBM benchmarks and the experimental results show that it can improve the final routing layout a lot with little loss of the completion rate.

  11. Pheromone Static Routing Strategy for Complex Networks

    Science.gov (United States)

    Hu, Mao-Bin; Henry, Y. K. Lau; Ling, Xiang; Jiang, Rui

    2012-12-01

    We adopt the concept of using pheromones to generate a set of static paths that can reach the performance of global dynamic routing strategy [Phys. Rev. E 81 (2010) 016113]. The path generation method consists of two stages. In the first stage, a pheromone is dropped to the nodes by packets forwarded according to the global dynamic routing strategy. In the second stage, pheromone static paths are generated according to the pheromone density. The output paths can greatly improve traffic systems' overall capacity on different network structures, including scale-free networks, small-world networks and random graphs. Because the paths are static, the system needs much less computational resources than the global dynamic routing strategy.

  12. Predication-Based Intelligence Routing on Telecommunications

    Institute of Scientific and Technical Information of China (English)

    DONGJun; HEJifeng; PANYunhe

    2004-01-01

    The routingtelecommunication networksbeing one of key issues of management influences the switch rate and load balance directly, and becomes more and more important as the telecommunication traffic increases at full speed. It was said that raising one percent of switch rate of current Chinese telecommunication networks would result in revenue about one billion Yuan RMB. On the basis of demerit-analysis of routing scheme being used, a new intelligent routing strategy based on multi-agent systems and recurrent neural network predication is presented, including routing strategy, Calls generating and agent~ recurrent neural network computation, simulation software design, results and discussion. The results show that the new one is better by virtue of its upstanding distribution and intelligence characters, and provides excellent solution to increase network switch rate and balance network load. Meanwhile, its applications will go beyond the scope of telecommunication networks. But whether the strategy will be perfect depends on the cooperation among operator, manufacturer and researchers.

  13. Next Generation Network Routing and Control Plane

    DEFF Research Database (Denmark)

    Fu, Rong

    proved, the dominating Border Gateway Protocol (BGP) cannot address all the issues that in inter-domain QoS routing. Thus a new protocol or network architecture has to be developed to be able to carry the inter-domain traffic with the QoS and TE consideration. Moreover, the current network control also...... of Service classes. Under the NGN context, there are plenty of proposals intending to accommodate the issues listed above. Path Computation Elements (PCE) proposed by IETF designs suitable network architecture that aiming at compute the QoS based paths for traffic transportation through intra- and inter...... (RACF) provides the platform that enables cooperation and ubiquitous integration between networks. In this paper, we investigate in the network architecture, protocols and algorithms for inter-domain QoS routing and traffic engineering. The PCE based inter-domain routing architecture is enhanced...

  14. Evolution Strategies in the Multipoint Connections Routing

    Directory of Open Access Journals (Sweden)

    L. Krulikovska

    2010-09-01

    Full Text Available Routing of multipoint connections plays an important role in final cost and quality of a found connection. New algorithms with better results are still searched. In this paper, a possibility of using the evolution strategies (ES for routing is presented. Quality of found connection is evaluated from the view of final cost and time spent on a searching procedure. First, parametrical analysis of results of the ES are discussed and compared with the Prim’s algorithm, which was chosen as a representative of the deterministic routing algorithms. Second, ways for improving the ES are suggested and implemented. The obtained results are reviewed. The main improvements are specified and discussed in conclusion.

  15. Trust Based Routing in Ad Hoc Network

    Science.gov (United States)

    Talati, Mikita V.; Valiveti, Sharada; Kotecha, K.

    Ad Hoc network often termed as an infrastructure-less, self- organized or spontaneous network.The execution and survival of an ad-hoc network is solely dependent upon the cooperative and trusting nature of its nodes. However, this naive dependency on intermediate nodes makes the ad-hoc network vulnerable to passive and active attacks by malicious nodes and cause inflict severe damage. A number of protocols have been developed to secure ad-hoc networks using cryptographic schemes, but all rely on the presence of trust authority. Due to mobility of nodes and limitation of resources in wireless network one interesting research area in MANET is routing. This paper offers various trust models and trust based routing protocols to improve the trustworthiness of the neighborhood.Thus it helps in selecting the most secure and trustworthy route from the available ones for the data transfer.

  16. Prevention of Routing Attacks In Manet

    Directory of Open Access Journals (Sweden)

    N.Rajesh

    2013-01-01

    Full Text Available Mobile Ad hoc Networks (MANET are easily prone to attacks due to its network infrastructure. In previous routing attacks the malicious node is isolated using naive fuzzy response decisions. In this paper a new technology of broadcasting the awareness information about attacker node to all the existing nodes in the network is discussed. The awareness approach is based on an extended Dempster-Shafer mathematical theory(D-S Theory. Dempster-Shafer mathematical theory is used to collect the evidence notion of importance factors. The adaptiveness of the mechanism allows to systematically cope with the identified MANET routing attacks. The intrusion response action in MANET was addressed by isolating uncooperative nodes based on the node reputation derived from their behaviors. Here the effectiveness of the approach with the consideration of the packet delivery ratio and routing cost were demonstrated using java swing concepts

  17. Towards Building an Intelligent Call Routing System

    Directory of Open Access Journals (Sweden)

    Thien Khai Tran

    2016-01-01

    Full Text Available This paper presents EduICR - an Intelligent Call Routing system. This system can route calls to the most appropriate agent using routing rules built by the text classifier. EduICR includes the following main components: telephone communication network; Vietnamese speech recognition; Text classifier/ Natural language processor and Vietnamese speech synthesis. To our best knowledge, this is one of the first systems in Vietnam to implement the integration mechanism of text processing and speech processing. This allows voice applications to be more intelligent, able to communicate with humans in natural language with high accuracy and reasonable speed. Having been built and tested in real environment, our system proves its accuracy attaining more than 95%.

  18. American Society of Echocardiography

    Science.gov (United States)

    American Society of Echocardiography Join Ase Member Portal Log In Membership Member Portal Log In Join ASE Renew Benefits Rates FASE – Fellow of the American Society of Echocardiography Member Referral Program FAQs Initiatives Advocacy ...

  19. African Americans and Glaucoma

    Science.gov (United States)

    ... Involved News About Us Donate In This Section African Americans and Glaucoma email Send this article to ... glaucoma is the leading cause of blindness in African Americans. Half of those with glaucoma don't ...

  20. American Vitiligo Research Foundation

    Science.gov (United States)

    ... life can acquire vitiligo Welcome to The American Vitiligo Foundation "Embracing Diversity" bracelets are available to help ... animal testing. Please Visit Our Donations Page American Vitiligo Research Foundation "We Walk By Faith, Not By ...

  1. Obesity and Hispanic Americans

    Science.gov (United States)

    ... and Data > Minority Population Profiles > Hispanic/Latino > Obesity Obesity and Hispanic Americans Among Mexican American women, 77 ... ss6304.pdf [PDF | 3.38MB] HEALTH IMPACT OF OBESITY More than 80 percent of people with type ...

  2. Obesity and Asian Americans

    Science.gov (United States)

    ... and Data > Minority Population Profiles > Asian American > Obesity Obesity and Asian Americans Non-Hispanic whites are 60% ... youthonline . [Accessed 05/25/2016] HEALTH IMPACT OF OBESITY More than 80 percent of people with type ...

  3. Arctic Ocean freshwater: How robust are model simulations?

    NARCIS (Netherlands)

    Jahn, A.; Aksenov, Y.; de Cuevas, B.A.; de Steur, L.; Häkkinen, S.; Hansen, E.; Herbaut, C.; Houssais, M.N.; Karcher, M.; Kauker, F.; Lique, C.; Nguyen, A.; Pemberton, P.; Worthen, D.; Zhang, J.

    2012-01-01

    The Arctic freshwater (FW) has been the focus of many modeling studies, due to the potential impact of Arctic FW on the deep water formation in the North Atlantic. A comparison of the hindcasts from ten ocean-sea ice models shows that the simulation of the Arctic FW budget is quite different in the

  4. Three more Mangrove trees growing locally in nature in freshwater

    NARCIS (Netherlands)

    Steenis, van C.G.G.J.

    1984-01-01

    In Christmas Island (Indian Ocean) the mangrove trees Bruguiera gymnorrhiza (L.) Sav., B. sexangula (Lour.) Poir. (Rhizophoraceae) and Heritiera littoralis Ait. (Sterculiaceae) are found inland near freshwater springs at some 20-30 m altitude, far from the beach. It is concluded that the inland stan

  5. Limnology of freshwater lakes of Schirmacher Oasis, East Antarctica

    Digital Repository Service at National Institute of Oceanography (India)

    Ingole, B.S.; Parulekar, A.H.

    Ten freshwater lakes in the Schirmacher Oasis, Antarctica, with water temperature varying from 1.0 to 7.9 degrees; dissolved oxygen from 10.4 to 13.8 mg l/1 and pH from 7.6 to 8.8, were studied biologically during January-February of 1985 and 1987...

  6. Characterization of CO2 leakage into the freshwater body

    DEFF Research Database (Denmark)

    Singh, Ashok; Delfs, Jens Olaf; Shao, H.;

    2013-01-01

    urrent research into CO2 capture and storage is dominated by improving the CO2 storage capacity. In this context, risk related to CO2 leakage is an important issue which may cause environmental problems, particularly when freshwater resources nearby are intruded by the CO2 plume. In this work...

  7. The effects of fisheries management practices on freshwater ecosystems

    OpenAIRE

    COWX I. G.; GERDEAUX D.

    2004-01-01

    Metadata only record The contributions presented at the European Inland Fisheries Advisory Commission Symposium on The Effects of Fisheries Management Practises on Freshwater Ecosystems in 2002 are reviewed. The principal mechanisms of inland fisheries management concentrate on four categories: fish stock enhancement (stocking and introductions); rehabilitation and habitat manipulation for fisheries purposes, including biomanipulation; fisheries regulations; and conservation and protection...

  8. Ecological risks of pesticides in freshwater ecosystems; Part 2: insecticides

    NARCIS (Netherlands)

    Brock, T.C.M.; Wijngaarden, van R.P.A.; Geest, van G.J.

    2000-01-01

    A literature review of freshwater model ecosystem studies with insecticides was performed to assess the NOEC ecosystem for individual compounds, to compare these threshold levels with water quality standards, and to evaluate the ecological consequences of exceeding these standards. Studies were judg

  9. The relation between international trade and freshwater scarcity

    NARCIS (Netherlands)

    Hoekstra, Arjen Y.

    2010-01-01

    It is becoming increasingly important to put freshwater issues in a global context. Local water depletion and pollution are often closely tied to the structure of the global economy. With increasing trade between nations and continents, water is more frequently used to produce exported goods. Intern

  10. Vectors of invasions in freshwater invertebrates and fishes

    Science.gov (United States)

    Fuller, Pam L.; Canning-Clode, João

    2015-01-01

    Without human assistance, the terrestrial environment and oceans represent barriers to the dispersal of freshwater aquatic organisms. The ability to overcome such barriers depends on the existence of anthropogenic vectors that can transport live organisms to new areas, and the species’ biology to survive the transportation and transplantation into the new environment (Johnson et al., 2006).

  11. Differential responses of freshwater wetland soils to sulphate pollution

    NARCIS (Netherlands)

    Lamers, L.P.M.; Dolle, ten G.E.; Berg, van den S.T.G.; Delft, van S.P.J.; Roelofs, J.G.M.

    2001-01-01

    Sulphate (SO42-) reduction rates are generally low in freshwater wetlands and are regulated by the scarce availability of the ion. Increased concentrations of this electron acceptor due to sulphur (S) pollution of groundwater and surface water may, however, lead to high sulphate reduction rates now

  12. Establishing a database of radionuclide transfer parameters for freshwater wildlife

    International Nuclear Information System (INIS)

    Environmental assessments to evaluate potentials risks to humans and wildlife often involve modelling to predict contaminant exposure through key pathways. Such models require input of parameter values, including concentration ratios, to estimate contaminant concentrations in biota based on measurements or estimates of concentrations in environmental media, such as water. Due to the diversity of species and the range in physicochemical conditions in natural ecosystems, concentration ratios can vary by orders of magnitude, even within similar species. Therefore, to improve model input parameter values for application in aquatic systems, freshwater concentration ratios were collated or calculated from national grey literature, Russian language publications, and refereed papers. Collated data were then input into an international database that is being established by the International Atomic Energy Agency. The freshwater database enables entry of information for all radionuclides listed in ICRP (1983), in addition to the corresponding stable elements, and comprises a total of more than 16,500 concentration ratio (CRwo-water) values. Although data were available for all broad wildlife groups (with the exception of birds), data were sparse for many organism types. For example, zooplankton, crustaceans, insects and insect larvae, amphibians, and mammals, for which there were CRwo-water values for less than eight elements. Coverage was most comprehensive for fish, vascular plants, and molluscs. To our knowledge, the freshwater database that has now been established represents the most comprehensive set of CRwo-water values for freshwater species currently available for use in radiological environmental assessments

  13. Representing Greenland ice sheet freshwater fluxes in climate models

    NARCIS (Netherlands)

    Lenaerts, Jan T M; Le Bars, Dewi; Van Kampenhout, Leo; Vizcaino, Miren; Enderlin, Ellyn M.; Van Den Broeke, Michiel R.

    2015-01-01

    Here we present a long-term (1850-2200) best estimate of Greenland ice sheet (GrIS) freshwater runoff that improves spatial detail of runoff locations and temporal resolution. Ice discharge is taken from observations since 2000 and assumed constant in time. Surface meltwater runoff is retrieved from

  14. A physically based model of global freshwater surface temperature

    NARCIS (Netherlands)

    Beek, van L.P.H.; Eikelboom, T.; Vliet, van M.T.H.; Bierkens, M.F.P.

    2012-01-01

    Temperature determines a range of physical properties of water and exerts a strong control on surface water biogeochemistry. Thus, in freshwater ecosystems the thermal regime directly affects the geographical distribution of aquatic species through their growth and metabolism and indirectly through

  15. New Records for the Freshwater Algae of Turkey

    OpenAIRE

    BAYKAL, Tülay; AKBULUT, Aydın; İlkay AÇIKGÖZ

    2009-01-01

    Algae samples were collected from important dam lakes and running waters of the Lower Euphrates Basin. Eighteen new records of Turkish freshwater algae were identified. Among these new records, 5 belong to Cyanophyta, 10 to Chlorophyta, 1 to Xanthophyta, and 2 to Bacillariophyta.

  16. High Diversity of Magnetotactic Deltaproteobacteria in a Freshwater Niche

    OpenAIRE

    Wang, Yinzhao; Lin, Wei; Li, Jinhua; Pan, Yongxin

    2013-01-01

    Knowledge of the diversity of magnetotactic bacteria in natural environments is crucial for understanding their contribution to various biological and geological processes. Here we report a high diversity of magnetotactic bacteria in a freshwater site. Ten out of 18 operational taxonomic units (OTUs) were affiliated with the Deltaproteobacteria. Some rod-shaped bacteria simultaneously synthesized greigite and magnetite magnetosomes.

  17. High diversity of magnetotactic deltaproteobacteria in a freshwater niche.

    Science.gov (United States)

    Wang, Yinzhao; Lin, Wei; Li, Jinhua; Pan, Yongxin

    2013-04-01

    Knowledge of the diversity of magnetotactic bacteria in natural environments is crucial for understanding their contribution to various biological and geological processes. Here we report a high diversity of magnetotactic bacteria in a freshwater site. Ten out of 18 operational taxonomic units (OTUs) were affiliated with the Deltaproteobacteria. Some rod-shaped bacteria simultaneously synthesized greigite and magnetite magnetosomes. PMID:23377941

  18. Establishing a database of radionuclide transfer parameters for freshwater wildlife.

    Science.gov (United States)

    Yankovich, T; Beresford, N A; Fesenko, S; Fesenko, J; Phaneuf, M; Dagher, E; Outola, I; Andersson, P; Thiessen, K; Ryan, J; Wood, M D; Bollhöfer, A; Barnett, C L; Copplestone, D

    2013-12-01

    Environmental assessments to evaluate potentials risks to humans and wildlife often involve modelling to predict contaminant exposure through key pathways. Such models require input of parameter values, including concentration ratios, to estimate contaminant concentrations in biota based on measurements or estimates of concentrations in environmental media, such as water. Due to the diversity of species and the range in physicochemical conditions in natural ecosystems, concentration ratios can vary by orders of magnitude, even within similar species. Therefore, to improve model input parameter values for application in aquatic systems, freshwater concentration ratios were collated or calculated from national grey literature, Russian language publications, and refereed papers. Collated data were then input into an international database that is being established by the International Atomic Energy Agency. The freshwater database enables entry of information for all radionuclides listed in ICRP (1983), in addition to the corresponding stable elements, and comprises a total of more than 16,500 concentration ratio (CRwo-water) values. Although data were available for all broad wildlife groups (with the exception of birds), data were sparse for many organism types. For example, zooplankton, crustaceans, insects and insect larvae, amphibians, and mammals, for which there were CRwo-water values for less than eight elements. Coverage was most comprehensive for fish, vascular plants, and molluscs. To our knowledge, the freshwater database that has now been established represents the most comprehensive set of CRwo-water values for freshwater species currently available for use in radiological environmental assessments. PMID:23103210

  19. Human impact on freshwater ecosystem services: a global perspective.

    Science.gov (United States)

    Dodds, Walter K; Perkin, Joshuah S; Gerken, Joseph E

    2013-08-20

    Human environmental change influences freshwaters as well as the regulating, provisioning, and cultural services that ecosystems provide worldwide. Here, we assess the global human impact on the potential value of six freshwater ecosystem services (ES) and estimate the proportion of each used globally (the mean value across all countries is in parentheses): biodiversity (0.37), disturbance regulation (0.24), commodities (0.39), greenhouse gases (0.09), water availability (0.10), and water quality (0.33). We also created a composite index of the impact. Using different valuation schemes, we found that humans have used potential global freshwater ES scaled by a relative value of roughly 4-20%, with a median of 16%. All countries use a considerable amount of the potential ES value, invalidating the idea that wealthier countries have less impact on their ES once they have developed. The data suggest that humans have diminished the potential ES provided by freshwaters across the globe and that factors associated with high population growth rates are related to the overall degradation. PMID:23885808

  20. Culture and Personality Among European American and Asian American Men

    OpenAIRE

    Eap, Sopagna; DeGarmo, David S.; Kawakami, Ayaka; Hara, Shelley N.; Hall, Gordon C.N.; Teten, Andra L.

    2008-01-01

    Personality differences between Asian American (N = 320) and European American men (N = 242) and also among Asian American ethnic groups (Korean, Chinese, Japanese, Filipino, and mixed Asian) are examined on the Big Five personality dimension. Personality structures for Asian Americans and European Americans closely replicate established norms. However, congruence is greater for European American and highly acculturated Asian American men than for low acculturated Asian American men. Similar ...

  1. Rapid climatic signal propagation from source to sink in a southern California sediment-routing system

    Science.gov (United States)

    Covault, J.A.; Romans, B.W.; Fildani, A.; McGann, M.; Graham, S.A.

    2010-01-01

    Terrestrial source areas are linked to deep-sea basins by sediment-routing systems, which only recently have been studied with a holistic approach focused on terrestrial and submarine components and their interactions. Here we compare an extensive piston-core and radiocarbon-age data set from offshore southern California to contemporaneous Holocene climate proxies in order to test the hypothesis that climatic signals are rapidly propagated from source to sink in a spatially restricted sediment-routing system that includes the Santa Ana River drainage basin and the Newport deep-sea depositional system. Sediment cores demonstrate that variability in rates of Holocene deep-sea turbidite deposition is related to complex ocean-atmosphere interactions, including enhanced magnitude and frequency of the North American monsoon and El Ni??o-Southern Oscillation cycles, which increased precipitation and fluvial discharge in southern California. This relationship is evident because, unlike many sediment-routing systems, the Newport submarine canyon-and-channel system was consistently linked tothe Santa Ana River,which maintained sediment delivery even during Holocene marine transgression and highstand. Results of this study demonstrate the efficiency of sediment transport and delivery through a spatially restricted, consistently linked routing system and the potential utility of deep-sea turbidite depositional trends as paleoclimate proxies in such settings. ?? 2010 by The University of Chicago.

  2. Sea ice decline and 21st century trans-Arctic shipping routes

    Science.gov (United States)

    Melia, N.; Haines, K.; Hawkins, E.

    2016-09-01

    The observed decline in Arctic sea ice is projected to continue, opening shorter trade routes across the Arctic Ocean, with potentially global economic implications. Here we quantify, using Coupled Model Intercomparison Project Phase 5 global climate model simulations calibrated to remove spatial biases, how projected sea ice loss might increase opportunities for Arctic transit shipping. By midcentury for standard open water vessels, the frequency of navigable periods doubles, with routes across the central Arctic becoming available. A sea ice-ship speed relationship is used to show that European routes to Asia typically become 10 days faster via the Arctic than alternatives by midcentury, and 13 days faster by late century, while North American routes become 4 days faster. Future greenhouse gas emissions have a larger impact by late century; the shipping season reaching 4-8 months in Representative Concentration Pathway (RCP)8.5 double that of RCP2.6, both with substantial interannual variability. Moderately, ice-strengthened vessels likely enable Arctic transits for 10-12 months by late century.

  3. Detours in Scope-Based Route Planning

    CERN Document Server

    Hliněný, Petr

    2012-01-01

    We study a dynamic scenario of the static route planning problem in road networks. Particularly, we put accent on the most practical dynamic case - increased edge weights (up to infinity). We show how to enhance the scope-based route planning approach presented at ESA'11 to intuitively by-pass closures by detours. Three variants of a detour "admissibility" are presented - from a simple one with straightforward implementation through its enhanced version to a full and very complex variant variant which always returns an optimal detour.

  4. Ambient noise near the sea-route

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Ambient noise data measured in an experiment conducted in shallow water near a sea-route were analyzed. It was observed that, at low frequency, the horizontal correlation has an obvious difference from that predicted by the classical ambient noise model. The theoretical analyses show that this phenomenon is caused by wind noise together with the discrete shipping noise nearby. An ambient noise model was proposed to include the effects caused by both the noise sources. Data measured at different times verify that the proposed model can be used to forecast the ambient noise field in shallow water near the sea-route.

  5. Ambient noise near the sea-route

    Institute of Scientific and Technical Information of China (English)

    HE Li; LI ZhengLin; PENG ZhaoHui

    2009-01-01

    Ambient noise data measured in an experiment conducted in shallow water near a sea-route were analyzed. It was observed that, at low frequency, the horizontal correlation has an obvious difference from that predicted by the classical ambient noise model. The theoretical analyses show that this phenomenon is caused by wind noise together with the discrete shipping noise nearby. An ambient noise model was proposed to include the effects caused by both the noise sources. Data measured at different times verify that the proposed model can be used to forecast the ambient noise field in shal-low water near the sea-route.

  6. Mathematical Aspects of Network Routing Optimization

    CERN Document Server

    Oliveira, Carlos AS

    2011-01-01

    Before the appearance of broadband links and wireless systems, networks have been used to connect people in new ways. Now, the modern world is connected through large-scale, computational networked systems such as the Internet. Because of the ever-advancing technology of networking, efficient algorithms have become increasingly necessary to solve some of the problems developing in this area. "Mathematical Aspects of Network Routing Optimization" focuses on computational issues arising from the process of optimizing network routes, such as quality of the resulting links and their reli

  7. An Improved Wireless Sensor Network Routing Algorithm

    Institute of Scientific and Technical Information of China (English)

    Shengmei Luo; Xue Li; Yiai Jin; Zhixin Sun

    2015-01-01

    High performance with low power consumption is an essential factor in wireless sensor networks (WSN). In order to address the issue on the lifetime and the consumption of nodes in WSNs, an improved ad hoc on⁃demand distance vector rout⁃ing (IAODV) algorithm is proposed based on AODV and LAR protocols. This algorithm is a modified on⁃demand routing al⁃gorithm that limits data forwarding in the searching domain, and then chooses the route on basis of hop count and power consumption. The simulation results show that the algorithm can effectively reduce power consumption as well as prolong the network lifetime.

  8. Optimized QoS Routing Algorithm

    Institute of Scientific and Technical Information of China (English)

    石明洪; 王思兵; 白英彩

    2004-01-01

    QoS routing is one of the key technologies for providing guaranteed service in IP networks. The paper focuses on the optimization problem for bandwidth constrained QoS routing, and proposes an optimal algorithm based on the global optimization of path bandwidth and hop counts. The main goal of the algorithm is to minimize the consumption of network resource, and at the same time to minimize the network congestion caused by irrational path selection. The simulation results show that our algorithm has lower call blocking rate and higher throughput than traditional algorithms.

  9. Latent factors and route choice behaviour

    DEFF Research Database (Denmark)

    Prato, Carlo Giacomo

    A behaviourally realistic description of the route choice process should consider variables that are both observable, such as travel time and cost, and unobservable, such as attitudes, perceptions, spatial abilities and network knowledge. This manuscript focuses on automotive route choice behaviour...... and Link Nested Logit. Estimates were produced from model specifications that considered level-of-service, label and facility dummy variables. Moreover, a modelling framework was designed to represent drivers’ choices as affected by the latent constructs extracted with factor analysis. Previous experience...

  10. Biodynamics of copper oxide nanoparticles and copper ions in an oligochaete: Part I: relative importance of water and sediment as exposure routes

    Science.gov (United States)

    Ramskov, Tina; Thit, Amalie; Croteau, Marie-Noele; Selck, Henriette

    2015-01-01

    Copper oxide (CuO) nanoparticles (NPs) are widely used, and likely released into the aquatic environment. Both aqueous (i.e., dissolved Cu) and particulate Cu can be taken up by organisms. However, how exposure routes influence the bioavailability and subsequent toxicity of Cu remains largely unknown. Here, we assess the importance of exposure routes (water and sediment) and Cu forms (aqueous and nanoparticulate) on Cu bioavailability and toxicity to the freshwater oligochaete, Lumbriculus variegatus, a head-down deposit-feeder. We characterize the bioaccumulation dynamics of Cu in L. variegatus across a range of exposure concentrations, covering both realistic and worst-case levels of Cu contamination in the environment. Both aqueous Cu (Cu-Aq; administered as Cu(NO3)2) and nanoparticulate Cu (CuO NPs), whether dispersed in artificial moderately hard freshwater or mixed into sediment, were weakly accumulated by L. variegatus. Once incorporated into tissues, Cu elimination was negligible, i.e., elimination rate constants were in general not different from zero for either exposure route or either Cu form. Toxicity was only observed after waterborne exposure to Cu-Aq at very high concentration (305 µgL-1), where all worms died. There was no relationship between exposure route, Cu form or Cu exposure concentration on either worm survival or growth. Slow feeding rates and low Cu assimilation efficiency (approximately 30%) characterized the uptake of Cu from the sediment for both Cu forms. In nature, L. variegatus is potentially exposed to Cu via both water and sediment. However, sediment progressively becomes the predominant exposure route for Cu in L. variegatus as Cu partitioning to sediment increases.

  11. Heart Disease and African Americans

    Science.gov (United States)

    ... Minority Population Profiles > Black/African American > Heart Disease Heart Disease and African Americans Although African American adults are ... were 30 percent more likely to die from heart disease than non-Hispanic whites. African American women are ...

  12. African American Suicide

    Science.gov (United States)

    African American Suicide Fact Sheet Based on 2012 Data (2014) Overview • In 2012, 2,357 African Americans completed suicide in the U.S. Of these, ... 46 per 100,000. • The suicide rate for African Americans ages 10-19 was 2.98 per ...

  13. American Indian Recipes.

    Science.gov (United States)

    Gurnoe, Katherine J.; Skjervold, Christian, Ed.

    Presenting some 60 to 70 Native American recipes, this document includes a brief introduction and a suggested reading list (15 citations related to American Indian foods). The introduction identifies five regional Native American cuisines as follows: in the Southwest, peppers and beans were made into chili, soups, guacamole, and barbecue sauces by…

  14. Selecting reliable and robust freshwater macroalgae for biomass applications.

    Directory of Open Access Journals (Sweden)

    Rebecca J Lawton

    Full Text Available Intensive cultivation of freshwater macroalgae is likely to increase with the development of an algal biofuels industry and algal bioremediation. However, target freshwater macroalgae species suitable for large-scale intensive cultivation have not yet been identified. Therefore, as a first step to identifying target species, we compared the productivity, growth and biochemical composition of three species representative of key freshwater macroalgae genera across a range of cultivation conditions. We then selected a primary target species and assessed its competitive ability against other species over a range of stocking densities. Oedogonium had the highest productivity (8.0 g ash free dry weight m⁻² day⁻¹, lowest ash content (3-8%, lowest water content (fresh weigh: dry weight ratio of 3.4, highest carbon content (45% and highest bioenergy potential (higher heating value 20 MJ/kg compared to Cladophora and Spirogyra. The higher productivity of Oedogonium relative to Cladophora and Spirogyra was consistent when algae were cultured with and without the addition of CO₂ across three aeration treatments. Therefore, Oedogonium was selected as our primary target species. The competitive ability of Oedogonium was assessed by growing it in bi-cultures and polycultures with Cladophora and Spirogyra over a range of stocking densities. Cultures were initially stocked with equal proportions of each species, but after three weeks of growth the proportion of Oedogonium had increased to at least 96% (±7 S.E. in Oedogonium-Spirogyra bi-cultures, 86% (±16 S.E. in Oedogonium-Cladophora bi-cultures and 82% (±18 S.E. in polycultures. The high productivity, bioenergy potential and competitive dominance of Oedogonium make this species an ideal freshwater macroalgal target for large-scale production and a valuable biomass source for bioenergy applications. These results demonstrate that freshwater macroalgae are thus far an under-utilised feedstock with

  15. Traffic Management Coordinator Evaluation of the Dynamic Weather Routes Concept and System

    Science.gov (United States)

    Gong, Chester

    2014-01-01

    Dynamic Weather Routes (DWR) is a weather-avoidance system for airline dispatchers and FAA traffic managers that continually searches for and advises the user of more efficient routes around convective weather. NASA and American Airlines (AA) have been conducting an operational trial of DWR since July 17, 2012. The objective of this evaluation is to assess DWR from a traffic management coordinator (TMC) perspective, using recently retired TMCs and actual DWR reroutes advisories that were rated acceptable by AA during the operational trial. Results from the evaluation showed that the primary reasons for a TMC to modify or reject airline reroute requests were related to airspace configuration. Approximately 80 percent of the reroutes evaluated required some coordination before implementation. Analysis showed TMCs approved 62 percent of the requested DWR reroutes, resulting in 57 percent of the total requested DWR time savings.

  16. Ant Colony Based Approach for Solving FPGA routing

    Directory of Open Access Journals (Sweden)

    Vinay Chopra

    2011-07-01

    Full Text Available This paper is based on an ant colony optimization algorithm (ASDR for solving FPGA routing for a route based routing constraint model in FPGA design architecture. In this approach FPGA routing task is transformed into a Boolean Satisfiabilty (SAT equation with the property that any assignment of input variables that satisfies the equation specifies a valid route. The Satisfiability equation is then modeled as Constraint Satisfaction problem, which helps in reducing procedural programming. Satisfying assignment for particular route will result in a valid routing and absence of a satisfying assignment implies that the layout is unroutable. In second step ant colony optimization algorithm is applied on the Boolean equation for solving routing alternatives utilizing approach of hard combinatorial optimization problems. The experimental results suggest that the developed ant colony optimization algorithm based router has taken extremely short CPU time as compared to classical Satisfiabilty based detailed router (SDR and finds all possible routes even for large FPGA circuits.

  17. Gulf-Wide Information System, Environmental Sensitivity Index Freshwater Fish Database, Geographic NAD83, LDWF (2001) [esi_freshwater_fish_LDWF_2001

    Data.gov (United States)

    Louisiana Geographic Information Center — This data set contains sensitive biological resource data for freshwater (inland) fish species in coastal Louisiana. Vector polygons represent water-bodies and...

  18. On Reducing the Impact of Interdomain Route Changes

    Science.gov (United States)

    Levanti, Kyriaki; Lee, Sihyung; Kim, Hyong S.

    Interdomain route changes are frequent and they can have negative impact on a network's operation: during route convergence, packets get delayed and dropped; after route convergence, changes in the egress point for reaching a destination can alter the network's intradomain traffic patterns and trigger new traffic-engineering. In this paper, we look into reducing the impact of interdomain route changes on the network's operation. First, we investigate a route decision process which avoids the selection of routes that cause egress point changes. However, this decision process does not consider the potential benefit of selecting a more preferred route even if it causes an egress point change. Then, we propose a system which only avoids route changes causing recurring intradomain traffic shifts by processing the route changes history and by selectively modifying route attributes which affect the route decision process. We evaluate both approaches using data from a major European ISP. The modified route decision process avoids 89% of the observed intradomain traffic shifts caused by interdomain route changes, whereas route attribute modifications reduce the number of traffic shifts on average by 25%, and as much as 50%.

  19. Mingling Multipath Routing With Quality Of Service

    Directory of Open Access Journals (Sweden)

    Dr. Shuchita Upadhyaya

    2011-09-01

    Full Text Available The QoS issue in the Internet have become essential for the successful transmission of multimedia applications . The basic problem of QoS routing is to find a path satisfying multiple constraints. It is concerned with identifying the path that will consider multiple parameters like bandwidth, delay, cost, hopcount etc. instead of one .To provide user- or application-level Quality of Service (QoS guarantee Multipath routing strategy can be used for the transmission of QoS sensitive traffic over the network. Multipath routing means using multiple paths instead of using single path to forward the traffic.If multiple paths are being used for the transmission of the traffic then the traffic will be redirected to the back up path if active path fails. In this way robustness can be achieved. On the other hand load balancing for communication network to avoid network congestion optimize network throughput also requires multi paths to distribute flows . Robustness load balancing are aspects of QoS routing . So multipath can be proved very valuable for Quality of service. This paper investigates the approaches of mingling Multipath Quality of service. The approaches considered are based on Dijkstra algorithm, Bellman ford algorithm, Resource reservation MPLS.

  20. Automated Flight Routing Using Stochastic Dynamic Programming

    Science.gov (United States)

    Ng, Hok K.; Morando, Alex; Grabbe, Shon

    2010-01-01

    Airspace capacity reduction due to convective weather impedes air traffic flows and causes traffic congestion. This study presents an algorithm that reroutes flights in the presence of winds, enroute convective weather, and congested airspace based on stochastic dynamic programming. A stochastic disturbance model incorporates into the reroute design process the capacity uncertainty. A trajectory-based airspace demand model is employed for calculating current and future airspace demand. The optimal routes minimize the total expected traveling time, weather incursion, and induced congestion costs. They are compared to weather-avoidance routes calculated using deterministic dynamic programming. The stochastic reroutes have smaller deviation probability than the deterministic counterpart when both reroutes have similar total flight distance. The stochastic rerouting algorithm takes into account all convective weather fields with all severity levels while the deterministic algorithm only accounts for convective weather systems exceeding a specified level of severity. When the stochastic reroutes are compared to the actual flight routes, they have similar total flight time, and both have about 1% of travel time crossing congested enroute sectors on average. The actual flight routes induce slightly less traffic congestion than the stochastic reroutes but intercept more severe convective weather.

  1. Efficient Networks Communication Routing Using Swarm Intelligence

    Directory of Open Access Journals (Sweden)

    Koushal Kumar

    2012-11-01

    Full Text Available As demonstrated by natural biological swarm’s collective intelligence has an abundance of desirable properties for problem-solving like in network routing. The focus of this paper is in the applications of swarm based intelligence in information routing for communication networks. As we know networks are growing and adopting new platforms as new technologies comes. Also according to new demands and requirements networks topologies and its complexity is increasing with time. Thus it is becoming very difficult to maintain the quality of services and reliability of the networks using current Networks routing algorithms. Thus Swarm intelligence (SI is the collective behavior of decentralized self-organized systems, natural or artificial. The concept is employed in work on artificial intelligence. A new class of algorithms, inspired by swarm intelligence is currently being developed that can potentially solve numerous problems of modern communications networks. These algorithms rely on the interaction of a multitude of simultaneously interacting agents. In this paper we give disadvantages of previously used network routing algorithms and how we can apply swarm intelligence to overcome these problems.

  2. Energy-Efficient Routing in GMPLS Network

    DEFF Research Database (Denmark)

    Wang, Jiayuan; Fagertun, Anna Manolova; Ruepp, Sarah Renée;

    2011-01-01

    In this paper, a GMPLS controlled core network model that takes energy efficiency into account is built using OPNET MODELER. By extending the standard GMPLS routing protocol -- OSPF-TE, we are able to spread desired energy related information over the local area, and subsequently use RSVP...

  3. Graphical route information on variable message signs

    NARCIS (Netherlands)

    Alkim, T.P.; Mede, P.H.J. van der; Janssen, W.H.

    2002-01-01

    Reports on experiments in the Netherlands on the use of graphical route information panels (GRIP) as part of variable message systems (VMS) providing information to drivers. GRIP appear to be as safe as regular VMS. Digestion of the information presented is initially quicker for regular VMS, but mot

  4. Optical Multicast Routing Under Light Splitter Constraints

    CERN Document Server

    Jawhar, Shadi; 10.1109/ITNG.2010.168

    2010-01-01

    During the past few years, we have observed the emergence of new applications that use multicast transmission. For a multicast routing algorithm to be applicable in optical networks, it must route data only to group members, optimize and maintain loop-free routes, and concentrate the routes on a subset of network links. For an all-optical switch to play the role of a branching router, it must be equipped with a light splitter. Light splitters are expensive equipments and therefore it will be very expensive to implement splitters on all optical switches. Optical light splitters are only implemented on some optical switches. That limited availability of light splitters raises a new problem when we want to implement multicast protocols in optical network (because usual multicast protocols make the assumption that all nodes have branching capabilities). Another issue is the knowledge of the locations of light splitters in the optical network. Nodes in the network should be able to identify the locations of light ...

  5. Routing Algorithms for Wireless Sensor Networks

    OpenAIRE

    Raicu, Ioan

    2004-01-01

    Our contribution in this paper is e3D, a diffusion based routing protocol that prolongs the system lifetime, evenly distributes the power dissipation throughout the network, and incurs minimal overhead for synchronizing communication. We compare e3D with other algorithms in terms of system lifetime, power dissipation distribution, cost of synchronization, and simplicity of the algorithm.

  6. Wales energy route map consultation : SDC response

    OpenAIRE

    Sustainable Development Commission Wales

    2005-01-01

    Sustainable Development Commission submission to the Welsh Assembly Government’s consultation on 'Energy Wales : route map to a clean, low-carbon and more competitive energy future for Wales'. Topics covered include Raising awareness, energy efficiency, renewable energy, coal/carbon capture storage, energy infrastructure and reducing carbon dioxide emissions. Publisher PDF

  7. Locating Depots for Capacitated Vehicle Routing

    CERN Document Server

    Goertz, Inge Li

    2011-01-01

    We study a location-routing problem in the context of capacitated vehicle routing. The input is a set of demand locations in a metric space and a fleet of k vehicles each of capacity Q. The objective is to locate k depots, one for each vehicle, and compute routes for the vehicles so that all demands are satisfied and the total cost is minimized. Our main result is a constant-factor approximation algorithm for this problem. To achieve this result, we reduce to the k-median-forest problem, which generalizes both k-median and minimum spanning tree, and which might be of independent interest. We give a (3+c)-approximation algorithm for k-median-forest, which leads to a (12+c)-approximation algorithm for the above location-routing problem, for any constant c>0. The algorithm for k-median-forest is just t-swap local search, and we prove that it has locality gap 3+2/t; this generalizes the corresponding result known for k-median. Finally we consider the "non-uniform" k-median-forest problem which has different cost ...

  8. Real Time Route for Dynamic Road Congestions

    Directory of Open Access Journals (Sweden)

    A. M. Riad

    2012-05-01

    Full Text Available Minimizing service delivery and travel time during rush hours downtown is strategic target for several organizations, especially the emergency organizations. This paper presents an On-line and Real-time Dynamic Route System (ORDRS which benefits from the advantages and integration between information system and communications technology. It utilizes Global Positioning System (GPS, Geographical Information Systems (GIS, and Global System for Mobile communications (GSM; for producing the real time routes for vehicles. GPS-Tracker is the main input device for ORDRS. It is fixated in a vehicle, sends vehicle's movement data (Geo-info to the control center wirelessly through either Short Message Service (SMS or General Packet Radio Service (GPRS. Geo-info includes time, date, longitude, latitude, speed, and etc., these data is classified over time during weekdays into interval time slices, each slice is 30 minutes. Speeds are treated by GIS tools to determine historical and real time speeds for each street segment in the road network which is being used for calculating time impedance (cost matrix for each street segment dynamically. ORDRS uses a cost matrix of the current time slice for determining the best route to each vehicle in duty attached. Several algorithms was used to calculate the shortest route, a comparison between Dijekstra and Yen algorithms was studied.

  9. Traffic disruption route Einstein near building 170

    CERN Multimedia

    A Lopez - TS/CE

    2005-01-01

    The TS/CE Group informs you that, for the duration of the work at Building 170, there may be some disruption to traffic on route Einstein in the vicinity of Building 170. The work is due to take place from the 14th to 18th February. For more information, please contact 165029. A. Lopez TS/CE

  10. A Geographical Heuristic Routing Protocol for VANETs

    Directory of Open Access Journals (Sweden)

    Luis Urquiza-Aguiar

    2016-09-01

    Full Text Available Vehicular ad hoc networks (VANETs leverage the communication system of Intelligent Transportation Systems (ITS. Recently, Delay-Tolerant Network (DTN routing protocols have increased their popularity among the research community for being used in non-safety VANET applications and services like traffic reporting. Vehicular DTN protocols use geographical and local information to make forwarding decisions. However, current proposals only consider the selection of the best candidate based on a local-search. In this paper, we propose a generic Geographical Heuristic Routing (GHR protocol that can be applied to any DTN geographical routing protocol that makes forwarding decisions hop by hop. GHR includes in its operation adaptations simulated annealing and Tabu-search meta-heuristics, which have largely been used to improve local-search results in discrete optimization. We include a complete performance evaluation of GHR in a multi-hop VANET simulation scenario for a reporting service. Our study analyzes all of the meaningful configurations of GHR and offers a statistical analysis of our findings by means of MANOVA tests. Our results indicate that the use of a Tabu list contributes to improving the packet delivery ratio by around 5% to 10%. Moreover, if Tabu is used, then the simulated annealing routing strategy gets a better performance than the selection of the best node used with carry and forwarding (default operation.

  11. Phone Routing using the Dynamic Memory Model

    DEFF Research Database (Denmark)

    Bendtsen, Claus Nicolaj; Krink, Thiemo

    2002-01-01

    In earlier studies a genetic algorithm (GA) extended with the dynamic memory model has shown remarkable performance on real-world-like problems. In this paper we experiment with routing in communication networks and show that the dynamic memory GA performs remarkable well compared to ant colony...

  12. From Africa via Europe to South America: migrational route of a species-rich genus of Neotropical lowland rain forest trees (Guatteria, Annonaceae)

    NARCIS (Netherlands)

    Erkens, R.H.J.; Maas, J.W.; Couvreur, T.L.P.

    2009-01-01

    Aim Several recent studies have suggested that a substantial portion of today's plant diversity in the Neotropics has resulted from the dispersal of taxa into that region rather than by vicariance. In general, three routes have been documented for the dispersal of taxa onto the South American contin

  13. Comparison of the Respiratory Metabolism of Juvenile Litopenaeus vannamei Cultured in Seawater and Freshwater

    Institute of Scientific and Technical Information of China (English)

    DING Sen; WANG Fang; DONG Shuanglin; LI Ying

    2014-01-01

    Litopenaeus vannamei, a euryhaline species, can be cultured at a wide range of salinities. The emergence of freshwater pond-culture of L. vannamei is an important prelude to the continued development of shrimp culture in China. In this study, we com-pared the respiratory metabolism of juvenile L. vannamei cultured in freshwater and saltwater by measuring their oxygen consump-tion rate (OCR), ammonium-type nitrogen excretion rate (AER) and pyruvate kinase (PK) and lactate dehydrogenase (LDH) activi-ties at different molting stages in order to physiecologically characterize juvenile L. vannamei under freshwater conditions. The re-sults showed that OCR was significantly higher in saltwater than in freshwater at all stages of molting cycle. However, variation of OCR among molting stages in saltwater was similar with that in freshwater, and the highest OCR was observed at post-molting stage. At all stages of molting cycle, AER was significantly higher in freshwater than in saltwater, and the highest was observed at post-molting stage. The activity of PK was significantly higher in saltwater than in freshwater. Conversely, the activity of LDH was higher in freshwater than in saltwater in general. Significant variation of PK and LDH activities in molting cycle was observed in saltwater and freshwater. The results indicated that aerobic metabolism of juvenile L. vannamei was more active in saltwater than in freshwater;while its protein metabolism was more active in freshwater than in saltwater.

  14. Comparison of the respiratory metabolism of juvenile Litopenaeus vannamei cultured in seawater and freshwater

    Science.gov (United States)

    Ding, Sen; Wang, Fang; Dong, Shuanglin; Li, Ying

    2013-11-01

    Litopenaeus vannamei, a euryhaline species, can be cultured at a wide range of salinities. The emergence of freshwater pond-culture of L. vannamei is an important prelude to the continued development of shrimp culture in China. In this study, we compared the respiratory metabolism of juvenile L. vannamei cultured in freshwater and saltwater by measuring their oxygen consumption rate (OCR), ammonium-type nitrogen excretion rate (AER) and pyruvate kinase (PK) and lactate dehydrogenase (LDH) activities at different molting stages in order to physiecologically characterize juvenile L. vannamei under freshwater conditions. The results showed that OCR was significantly higher in saltwater than in freshwater at all stages of molting cycle. However, variation of OCR among molting stages in saltwater was similar with that in freshwater, and the highest OCR was observed at post-molting stage. At all stages of molting cycle, AER was significantly higher in freshwater than in saltwater, and the highest was observed at post-molting stage. The activity of PK was significantly higher in saltwater than in freshwater. Conversely, the activity of LDH was higher in freshwater than in saltwater in general. Significant variation of PK and LDH activities in molting cycle was observed in saltwater and freshwater. The results indicated that aerobic metabolism of juvenile L. vannamei was more active in saltwater than in freshwater; while its protein metabolism was more active in freshwater than in saltwater.

  15. Five new species of Urocleidoides (Monogenoidea) (Mizelle and Price 1964) Kritsky, Thatcher, and Boeger, 1986, parasitizing the gills of Panamanian freshwater fishes.

    Science.gov (United States)

    Mendoza-Franco, Edgar F; Reina, Ruth G

    2008-08-01

    During an investigation of gill monogenoidean parasites from freshwater fishes in central Panama, 5 new species of Urocleidoides (sensu stricto) were found: Urocleidoides cultellus n. sp., Urocleidoides visiofortatus n. sp., and Urocleidoides advenai n. sp. from the gymnotiform Brachyhypopomus occidentalis (Hypopomidae); Urocleidoides neotropicalis n. sp. and Urocleidoides piriatiu n. sp. from the characiforms Saccodon dariensis (Parodontidae) and Ctenolucius beani (Ctenoluciidae), respectively. Our findings represent the first known species of Urocleidoides from these fishes in Central America and demonstrate that they are morphologically linked to their South American congeners. PMID:18837577

  16. Optimal Route Selection Method Based on Vague Sets

    Institute of Scientific and Technical Information of China (English)

    GUO Rui; DU Li min; WANG Chun

    2015-01-01

    Optimal route selection is an important function of vehicle trac flow guidance system. Its core is to determine the index weight for measuring the route merits and to determine the evaluation method for selecting route. In this paper, subjective weighting method which relies on driver preference is used to determine the weight and the paper proposes the multi-criteria weighted decision method based on vague sets for selecting the optimal route. Examples show that, the usage of vague sets to describe route index value can provide more decision-making information for route selection.

  17. Escape probability based routing for ad hoc networks

    Institute of Scientific and Technical Information of China (English)

    Zhang Xuanping; Qin Zheng; Li Xin

    2006-01-01

    Routes in an ad hoc network may fail frequently because of node mobility. Stability therefore can be an important element in the design of routing protocols. The node escape probability is introduced to estimate the lifetime and stability of link between neighboring nodes and the escape probability based routing (EPBR) scheme to discover stable routes is proposed. Simulation results show that the EPBR can discover stable routes to reduce the number of route rediscovery, and is applicable for the situation that has highly dynamic network topology with broad area of communication.

  18. Optimal dosage and route of administration of methotrexate in rheumatoid arthritis: a systematic review of the literature

    OpenAIRE

    Visser, K.; van der Heijde, D

    2008-01-01

    Objectives: To review systematically the available literature on the optimal dosage and route of administration of methotrexate in patients with rheumatoid arthritis (RA), as an evidence base for generating clinical practice recommendations. Methods: A systematic literature search was carried out in MEDLINE, EMBASE, Cochrane Library and American College of Rheumatology/European League Against Rheumatism meeting abstracts, searching for randomised controlled trials evaluating various dosages o...

  19. FishTraits: a database of ecological and life-history traits of freshwater fishes of the United States

    Science.gov (United States)

    Angermeier, Paul L.; Frimpong, Emmanuel A.

    2011-01-01

    The need for integrated and widely accessible sources of species traits data to facilitate studies of ecology, conservation, and management has motivated development of traits databases for various taxa. In spite of the increasing number of traits-based analyses of freshwater fishes in the United States, no consolidated database of traits of this group exists publicly, and much useful information on these species is documented only in obscure sources. The largely inaccessible and unconsolidated traits information makes large-scale analysis involving many fishes and/or traits particularly challenging. We have compiled a database of > 100 traits for 809 (731 native and 78 nonnative) fish species found in freshwaters of the conterminous United States, including 37 native families and 145 native genera. The database, named Fish Traits, contains information on four major categories of traits: (1) trophic ecology; (2) body size, reproductive ecology, and life history; (3) habitat preferences; and (4) salinity and temperature tolerances. Information on geographic distribution and conservation status was also compiled. The database enhances many opportunities for conducting research on fish species traits and constitutes the first step toward establishing a central repository for a continually expanding set of traits of North American fishes.

  20. XX/XO, a rare sex chromosome system in Potamotrygon freshwater stingray from the Amazon Basin, Brazil.

    Science.gov (United States)

    de Souza Valentim, Francisco Carlos; Porto, Jorge Ivan Rebelo; Bertollo, Luiz Antonio Carlos; Gross, Maria Claudia; Feldberg, Eliana

    2013-09-01

    Potamotrygonidae is a representative family of South American freshwater elasmobranchs. Cytogenetic studies were performed in a Potamotrygon species from the middle Negro River, Amazonas, Brazil, here named as Potamotrygon sp. C. Mitotic and meiotic chromosomes were analyzed using conventional staining techniques, C-banding, and detection of the nucleolus organizing regions (NOR) with Silver nitrate (Ag-NOR). The diploid number was distinct between sexes, with males having 2n = 67 chromosomes, karyotype formula 19m + 8sm + 10st + 30a, and fundamental number (FN) = 104, and females having 2n = 68 chromosomes, karyotype formula 20m + 8sm + 10st + 30a, and FN = 106. A large chromosome, corresponding to pair number two in the female karyotype, was missing in the male complement. Male meiotic cells had 33 bivalents plus a large univalent chromosome in metaphase I, and n = 33 and n = 34 chromosomes in metaphase II. These characteristics are consistent with a sex chromosome system of the XX/XO type. Several Ag-NOR sites were identified in both male and female karyotypes. Positive C-banding was located only in the centromeric regions of the chromosomes. This sex chromosome system, which rarely occurs in fish, is now being described for the first time among the freshwater rays of the Amazon basin.

  1. PNW River Reach Files -- 1:100k LLID Routed Streams (routes)

    Data.gov (United States)

    Pacific States Marine Fisheries Commission — This feature class includes the ROUTE features from the 2001 version of the PNW River Reach files Arc/INFO coverage. Separate, companion feature classes are also...

  2. Route guidance strategies revisited: Comparison and evaluation in an asymmetric two-route traffic system

    CERN Document Server

    He, Zhengbing; Guan, Wei

    2013-01-01

    To alleviate traffic congestion, a variety of route guidance strategies has been proposed for intelligent transportation systems. A number of the strategies are proposed and investigated on a symmetric two-route traffic system over the past decade. To evaluate the strategies in a more general scenario, this paper conducts eight prevalent strategies on a asymmetric two-route traffic network with different slowdown behaviors on alternative routes. The results show that only mean velocity feedback strategy is able to equalize travel time, i.e., approximate user optimality; while the others fail due to incapability of establishing relations between the feedback parameters and travel time. The paper helps better understand these strategies, and suggests mean velocity feedback strategy if the authority intends to achieve user optimality.

  3. RSRP: A Robust Secure Routing Protocol in MANET

    Directory of Open Access Journals (Sweden)

    Sinha Ditipriya

    2014-05-01

    Full Text Available In this paper, we propose a novel algorithm RSRP to build a robust secure routing protocol in mobile ad-hoc networks (MANETs. This algorithm is based on some basic schemes such as RSA_CRT for encryption and decryption of messages; CRT for safety key generation, Shamir’s secret sharing principle for generation of secure routes. Those routes which are free from any malicious node and which belong to the set of disjoint routes between a source-destination pair are considered as probable routes. Shamir’s secret sharing principle is applied on those probable routes to obtain secure routes. Finally, most trustworthy and stable route is selected among those secure routes. Selection of the final route depends on some criteria of the nodes present in a route e.g.: battery power, mobility and trust value. In addition, complexity of key generation is reduced to a large extent by using RSA-CRT instead of RSA. In turn, the routing becomes less expensive and most secure and robust one. Performance of this routing protocol is then compared with non-secure routing protocols (AODV and DSR, secure routing scheme using secret sharing, security routing protocol using ZRP and SEAD depending on basic characteristics of these protocols. All such comparisons show that RSRP shows better performance in terms of computational cost, end-to-end delay and packet dropping in presence of malicious nodes in the MANET, keeping the overhead in terms of control packets same as other secure routing protocols.

  4. The potential of freshwater macroalgae as a biofuels feedstock and the influence of nutrient availability on freshwater macroalgal biomass production

    Science.gov (United States)

    Yun, Jin-Ho

    Extensive efforts have been made to evaluate the potential of microalgae as a biofuel feedstock during the past 4-5 decades. However, filamentous freshwater macroalgae have numerous characteristics that favor their potential use as an alternative algal feedstock for biofuels production. Freshwater macroalgae exhibit high rates of areal productivity, and their tendency to form dense floating mats on the water surface imply significant reductions in harvesting and dewater costs compared to microalgae. In Chapter 1, I reviewed the published literature on the elemental composition and energy content of five genera of freshwater macroalgae. This review suggested that freshwater macroalgae compare favorably with traditional bio-based energy sources, including terrestrial residues, wood, and coal. In addition, I performed a semi-continuous culture experiment using the common Chlorophyte genus Oedogonium to investigate whether nutrient availability can influence its higher heating value (HHV), productivity, and proximate analysis. The experimental study suggested that the most nutrient-limited growth conditions resulted in a significant increase in the HHV of the Oedogonium biomass (14.4 MJ/kg to 16.1 MJ/kg). Although there was no significant difference in productivity between the treatments, the average dry weight productivity of Oedogonium (3.37 g/m2/day) was found to be much higher than is achievable with common terrestrial plant crops. Although filamentous freshwater macroalgae, therefore, have significant potential as a renewable source of bioenergy, the ultimate success of freshwater macroalgae as a biofuel feedstock will depend upon the ability to produce biomass at the commercial-scale in a cost-effective and sustainable manner. Aquatic ecology can play an important role to achieve the scale-up of algal crop production by informing the supply rates of nutrients to the cultivation systems, and by helping to create adaptive production systems that are resilient to

  5. Route Recapitulation and Route Loyalty in Homing Pigeons: Pilotage From 25 km?

    Science.gov (United States)

    Biro, Dora; Meade, Jessica; Guilford, Tim

    2006-01-01

    We utilised precision Global Positioning System (GPS) tracking to examine the homing paths of pigeons (Columba livia) released 20 times consecutively 25 km from the loft. By the end of the training phase, birds had developed highly stereotyped yet individually distinct routes home, with detailed recapitulation evident at each stage of the journey. Following training, birds also participated in a series of releases from novel sites at perpendicular distances of up to 3 km from their established routes. Results showed that subjects were attracted back to their established routes and recapitulated them from the point of contact. Naïve conspecifics (yoked controls) released from the same off-route sites confirmed that the experienced birds' route choices were not influenced by constraints exerted by terrain features, but that increased experience with the general area conferred a homing advantage in the form of more efficient flight tracks, even from these novel sites. Patterns in the paths taken by experienced birds to rejoin their established routes are discussed with reference to navigational mechanisms employed by homing pigeons in their familiar area.

  6. Materials Processing Routes to Trap-Free Halide Perovskites

    KAUST Repository

    Buin, Andrei

    2014-11-12

    © 2014 American Chemical Society. Photovoltaic devices based on lead iodide perovskite films have seen rapid advancements, recently achieving an impressive 17.9% certified solar power conversion efficiency. Reports have consistently emphasized that the specific choice of growth conditions and chemical precursors is central to achieving superior performance from these materials; yet the roles and mechanisms underlying the selection of materials processing route is poorly understood. Here we show that films grown under iodine-rich conditions are prone to a high density of deep electronic traps (recombination centers), while the use of a chloride precursor avoids the formation of key defects (Pb atom substituted by I) responsible for short diffusion lengths and poor photovoltaic performance. Furthermore, the lowest-energy surfaces of perovskite crystals are found to be entirely trap-free, preserving both electron and hole delocalization to a remarkable degree, helping to account for explaining the success of polycrystalline perovskite films. We construct perovskite films from I-poor conditions using a lead acetate precursor, and our measurement of a long (600 ± 40 nm) diffusion length confirms this new picture of the importance of growth conditions.

  7. Chain-Chain Based Routing Protocol

    Directory of Open Access Journals (Sweden)

    Samia A Ali

    2011-05-01

    Full Text Available Wireless sensor network (WSN is an emerging technology for monitoring physical world. WSNs consist of large numbers of sensor nodes operated by battery mostly in harsh environment. Thus energy conservation is a primary issue for organization of these sensor nodes. Another crucial issue is the data delivery time by sensor nodes to the sink node, especially in Military, medical fields, and security monitoring systems where minimum delay is desirable. Number of protocols has been proposed in the literature for routing. One of such protocols is the cluster based routing protocol LEACH (low energy adaptive clustering hierarchy. LEACH protocol organizes WSN into a set of clusters and a periodic voting for cluster head is performed in order to be evenly distributed among all the sensors of the WSN. This periodical cluster head voting in LEACH, however, consumes an amount of non-negligible energy and other resources. For energy conservation, PEGASIS (power efficient gathering in sensor information systems a near optimal chain-based protocol has been proposed, however, it is faced with the challenge of long delay for the transmitted data. Another routing protocol called CCM (Chain-Cluster based Mixed routing, which is mainly a hybrid of LEACH and PEGASIS is proposed, the consumed energy increases as network size increases. In this paper, we propose an efficient routing protocol called CCBRP (Chain-Chain based routing protocol, it achieves both minimum energy consumption and minimum delay. The CCBRP protocol mainly divides a WSN into a number of chains (Greedy algorithm is used to form each chain as in PEGSIS protocol and runs in two phases. In the first phase, sensor nodes in each chain transmit data to their chain leader nodes in parallel. In the second phase, all chain leader nodes form a chain (also, using Greedy algorithm and choose randomly a leader node then all chain leader nodes send their data to this chosen leader node. This chosen leader node

  8. Congestion control and routing over satellite networks

    Science.gov (United States)

    Cao, Jinhua

    Satellite networks and transmissions find their application in fields of computer communications, telephone communications, television broadcasting, transportation, space situational awareness systems and so on. This thesis mainly focuses on two networking issues affecting satellite networking: network congestion control and network routing optimization. Congestion, which leads to long queueing delays, packet losses or both, is a networking problem that has drawn the attention of many researchers. The goal of congestion control mechanisms is to ensure high bandwidth utilization while avoiding network congestion by regulating the rate at which traffic sources inject packets into a network. In this thesis, we propose a stable congestion controller using data-driven, safe switching control theory to improve the dynamic performance of satellite Transmission Control Protocol/Active Queue Management (TCP/AQM) networks. First, the stable region of the Proportional-Integral (PI) parameters for a nominal model is explored. Then, a PI controller, whose parameters are adaptively tuned by switching among members of a given candidate set, using observed plant data, is presented and compared with some classical AQM policy examples, such as Random Early Detection (RED) and fixed PI control. A new cost detectable switching law with an interval cost function switching algorithm, which improves the performance and also saves the computational cost, is developed and compared with a law commonly used in the switching control literature. Finite-gain stability of the system is proved. A fuzzy logic PI controller is incorporated as a special candidate to achieve good performance at all nominal points with the available set of candidate controllers. Simulations are presented to validate the theory. An effocient routing algorithm plays a key role in optimizing network resources. In this thesis, we briefly analyze Low Earth Orbit (LEO) satellite networks, review the Cross Entropy (CE

  9. Route Monopolie and Optimal Nonlinear Pricing

    Science.gov (United States)

    Tournut, Jacques

    2003-01-01

    To cope with air traffic growth and congested airports, two solutions are apparent on the supply side: 1) use larger aircraft in the hub and spoke system; or 2) develop new routes through secondary airports. An enlarged route system through secondary airports may increase the proportion of route monopolies in the air transport market.The monopoly optimal non linear pricing policy is well known in the case of one dimension (one instrument, one characteristic) but not in the case of several dimensions. This paper explores the robustness of the one dimensional screening model with respect to increasing the number of instruments and the number of characteristics. The objective of this paper is then to link and fill the gap in both literatures. One of the merits of the screening model has been to show that a great varieD" of economic questions (non linear pricing, product line choice, auction design, income taxation, regulation...) could be handled within the same framework.VCe study a case of non linear pricing (2 instruments (2 routes on which the airline pro_ddes customers with services), 2 characteristics (demand of services on these routes) and two values per characteristic (low and high demand of services on these routes)) and we show that none of the conclusions of the one dimensional analysis remain valid. In particular, upward incentive compatibility constraint may be binding at the optimum. As a consequence, they may be distortion at the top of the distribution. In addition to this, we show that the optimal solution often requires a kind of form of bundling, we explain explicitly distortions and show that it is sometimes optimal for the monopolist to only produce one good (instead of two) or to exclude some buyers from the market. Actually, this means that the monopolist cannot fully apply his monopoly power and is better off selling both goods independently.We then define all the possible solutions in the case of a quadratic cost function for a uniform

  10. Characterization of freshwater mosses as indicators of radioactive contamination

    International Nuclear Information System (INIS)

    The necessity of indicators of freshwater contamination has developed the interest for aquatic mosses. From a fundamental point of view, studying the influence of some biotic and abiotic factors has permitted to better know the mechanisms of radionuclides accumulation by these bryophytes. From a radioecological point of view, simulating real cases of water contamination has allowed to give results a very interesting representativeness. The use of mosses as bio-indicators was applied for two in situ experiments, the results of which have been interpreted from those obtained in laboratory. Finally, an approach by a mathematical model has showed that it is possible to have, in a middle term, an evaluation tool of freshwater contamination, based on the radionuclides concentrations measured in aquatic mosses. (author). refs., 57 figs., 24 tabs

  11. Histopathology of Marine and Freshwater Fish Lymphocytosis Disease Virus (LCDV)

    International Nuclear Information System (INIS)

    Lymphocytosis disease (LCD) in fishes is caused by the agent called lymphocytosis disease virus (LCDV). LCDV is a chronic and benign virus. The disease affects 96 species of marine and fresh water fishes ranged among 34 families in the world. Affected fish with LCD has a typical external symptom with clusters consisted of enormously hypertrophied dermal cells on the skin and fins. The hypertrophied cells, generally named lymphocytosis cells, have a thick hyaline capsule, an enlarged nucleus and prominent basophilic cytoplasmic inclusions. Among the four species of fishes, olive flounder Paralichthys olivaceus, and rockfish Sebastes schlegeli were marine cultured fish, and gourami Trichogaster leeri and painted glass fish Channa baculis were freshwater ornamental fish. Although LCD causes low mortality, the disfigurement of infected fish can make them unsellable. Thus LCD has resulted in an important economic loss in the aquaculture industry. This study of histopathology may be adequate for a presumptive diagnosis of lymphocytosis diseases both in marine and freshwater fish species. (author)

  12. Ammonium transformation in a nitrogen-rich tidal freshwater marsh

    DEFF Research Database (Denmark)

    Gribsholt, B.; Andersson, M.; Boschker, H.T.S.;

    2006-01-01

    The fate and transport of watershed-derived ammonium in a tidal freshwater marsh fringing the nutrient rich Scheldt River, Belgium, was quantified in a whole ecosystem 15N labeling experiment. In late summer (September) we added 15N-NH4+ to the flood water entering a 3477 m2 tidal freshwater marsh...... area, and traced the ammonium processing and retention in four subsequent tide cycles. In this paper we present the results for the water-phase components of the marsh system and compare them to a similar experiment conducted in spring/early summer (May). Changes in concentration and isotopic......, but the absolute ammonium transformation rate was 3 times higher in May. While the marsh surface area was crucial for nitrification in May this was less pronounced in September. Denitrification, on the other hand, appeared more important in September compared to May....

  13. Removal of triazine herbicides from freshwater systems using photosynthetic microorganisms

    International Nuclear Information System (INIS)

    The uptake of the triazine herbicides, atrazine and terbutryn, was determined for two freshwater photosynthetic microorganisms, the green microalga Chlorella vulgaris and the cyanobacterium Synechococcus elongatus. An extremely rapid uptake of both pesticides was recorded, although uptake rate was lower for the cyanobacterium, mainly for atrazine. Other parameters related to the herbicide bioconcentration capacity of these microorganisms were also studied. Growth rate, biomass, and cell viability in cultures containing herbicide were clearly affected by herbicide uptake. Herbicide toxicity and microalgae sensitivity were used to determine the effectiveness of the bioconcentration process and the stability of herbicide removal. C. vulgaris showed higher bioconcentration capability for these two triazine herbicides than S. elongatus, especially with regard to terbutryn. This study supports the usefulness of such microorganisms, as a bioremediation technique in freshwater systems polluted with triazine herbicides

  14. Stateless and Delivery Guaranteed Geometric Routing on Virtual Coordinate System

    CERN Document Server

    Liu, Ke

    2008-01-01

    Stateless geographic routing provides relatively good performance at a fixed overhead, which is typically much lower than conventional routing protocols such as AODV. However, the performance of geographic routing is impacted by physical voids, and localization errors. Accordingly, virtual coordinate systems (VCS) were proposed as an alternative approach that is resilient to localization errors and that naturally routes around physical voids. However, VCS also faces virtual anomalies, causing their performance to trail geographic routing. In existing VCS routing protocols, there is a lack of an effective stateless and delivery guaranteed complementary routing algorithm that can be used to traverse voids. Most proposed solutions use variants of flooding or blind searching when a void is encountered. In this paper, we propose a spanning-path virtual coordinate system which can be used as a complete routing algorithm or as the complementary algorithm to greedy forwarding that is invoked when voids are encountere...

  15. Adaptive routing in wireless communication networks using swarm intelligence

    Science.gov (United States)

    Arabshahi, P.; Gray, A.; Kassabalidis, I.; Das, A.; Narayanan, S.; Sharkawi, M. El; Marks, R. J.

    2001-01-01

    In this paper we focus on the network routing problem, and survey swarm intelligent approaches for its efficient solution, after a brief overview of power-aware routing schemes, which are important in the network examples outlined above.

  16. Feeding ecology of the freshwater crab Trichodactylus borellianus (Decapoda: Trichodactylidae in the floodplain of the Paraná River, southern South America

    Directory of Open Access Journals (Sweden)

    Verónica Williner

    2013-09-01

    Full Text Available Freshwater crabs are not commonly considered to be an important group in trophic webs, and this might be due to a lack of knowledge about their trophic roles in aquatic ecosystems. Trichodactylus borellianus is one of the most common and widely distributed freshwater crabs in the floodplains of the southern South American rivers. The main objective of the present study was to examine the trophic role of T. borellianus, in the floodplain of the Paraná River, and its relationships with the freshwater littoral community. The trophic spectrum of this species was characterized for both sexes and individuals of different sizes (adults and juveniles, throughout daily and seasonal cycles. Samples were collected from the aquatic vegetation of three shallow lakes. The diet composition and the feeding activity of T. borellianus were evaluated through the examination of the stomach contents and their degree of emptiness. This crab species consumed several plant and animal items, including amoebas, rotifers, oligochaetes, copepods, cladocerans, and insect larvae. Moreover, this species consumes filamentous and unicellular algae, diatoms, fungi, and macrophytic remains. The predatory habits varied with the season and time of day, and variations in the feeding activity of the juveniles and adults were detected and documented. The diversity of food items eaten by this crab suggests that its trophic role in the community as an omnivore and opportunistic predator provides a connection among several trophic levels from both aquatic and terrestrial communities.

  17. UV radiation and freshwater zooplankton: damage, protection and recovery

    OpenAIRE

    Rautio, Milla; Tartarotti, Barbara

    2010-01-01

    While many laboratory and field studies show that zooplankton are negatively affected when exposed to high intensities of ultraviolet radiation (UVR), most studies also indicate that zooplankton are well adapted to cope with large variations in their UVR exposure in the pelagic zone of lakes. The response mechanisms of zooplankton are diverse and efficient and may explain the success and richness of freshwater zooplankton in optically variable waters. While no single behavioural or physiologi...

  18. CAGE BREEDING OF WARM WATER FRESHWATER FISH SPECIES

    Directory of Open Access Journals (Sweden)

    Roman Safner

    2008-10-01

    Full Text Available In the 1970s, Croatia became actively involved in the contemporary trend of breeding fish in floating cages. In addition to various species of marine fishes, breeding was attempted with trout, carp, catfish, cisco and salmon. Of the above freshwater fish species, specific standards were established only for the cage breeding of rainbow trout. Cage breeding of the remaining species remained at the level of occasional attempts, with more of an experimental than a commercial character. The regular attempts to master this technique for cage breeding of warm water freshwater fish species were aimed at achieving the known benefits of such breeding, such as simplicity of implementing technological measures, easier establishment of the breeding system, simpler manipulation, the possibility of denser colonies per unit volume with a high level of production, easier adaptations to market conditions and fewer initial structural investments. Despite the many advantages, the main reasons for the lack of greater implementation of the cage breeding technology for warm water species of freshwater fish include problems in obtaining the appropriate category and quantity of healthy fry, the specificity and applicability of physical and chemical properties of the recipients and human error. In evaluating the advantages and disadvantages, the final decision on the justification of cage breeding for individual warm water freshwater species must be based on both biological and economic factors. Based on the knowledge of cage breeding acquired to date, the rule for virtually all intensive breeding systems is that it is only recommended for those species with high market demand and a high market price. The technology that demands nutrition with highly concentrated feed and other production expenditures is costly, and is therefore not profitable with less expensive fish species. Furthermore, production must be market oriented, i.e. the appropriate market research measures

  19. Development of a diet for rearing juvenile freshwater mussels

    OpenAIRE

    Gatenby, Catherine M.

    1994-01-01

    Over 100 species of freshwater mussels (Unionidae) are endangered or threatened in the United States, and another dozen species support a declining commercial harvest of shells for the cultured pearl industry in Asia. Because of these Significant declines in abundance, a study was undertaken to develop a diet for rearing juvenile mussels, with the goal of long-term propagation of rare species. Three trials were conducted to test various tri-algal and commercial diets and to ...

  20. Prevalence of Foodborne Pathogens in Freshwater Fish in Latvia.

    Science.gov (United States)

    Terentjeva, Margarita; Eizenberga, Inga; Valciņa, Olga; Novoslavskij, Aleksandr; Strazdiņa, Vita; Bērziņš, Aivars

    2015-11-01

    The aim of this study was to detect the prevalence of Salmonella spp., Listeria monocytogenes, and Yersinia enterocolitica in freshwater fish in Latvia. In total, 235 samples, including freshly caught fish from fives lakes (n = 129) and fish from retail markets (n = 106), were collected from April 2014 to December 2014 in Latvia. Samples were tested according to International Organization for Standardization methods. No Salmonella spp. were found in fresh fish from lakes or in commercially available fish. In contrast, the overall prevalence of L. monocytogenes and Y. enterocolitica in freshwater fish was 13% (30 of 235) and 14% (34 of 235), respectively, and no significant difference between the prevalence of L. monocytogenes and Y. enterocolitica was observed (P > 0.05). All Y. enterocolitica isolates belonged to the nonpathogenic 1A biotype. Molecular serotyping of L. monocytogenes revealed that the most distributed serogroup was 1/2a-3a (65%), followed by 1/2c-3c (25%), 1/2b-3b (5%), and 4b, 4d, 4e (5%). The prevalence of L. monocytogenes and Y. enterocolitica in freshwater lake fish was 2% (2 of 129) and 3% (4 of 129), respectively. In contrast, the prevalence of L. monocytogenes and Y. enterocolitica in fish at retail markets was 26% (28 of 106) and 28% (30 of 106), respectively. In retail samples, 9 of 58 positive fish contained both L. monocytogenes and Y. enterocolitica. In general, differences in the prevalences of L. monocytogenes and Y. enterocolitica in retail samples were significantly higher than those in freshly caught fish (P < 0.05). The results of this study indicate that freshwater fish could be an important source of Y. enterocolitica and L. monocytogenes for consumers in Latvia.

  1. A REVIEW OF PHYTOPLANKTON ECOLOGY IN FRESHWATER LAKES OF INDIA

    OpenAIRE

    Giripunje, Manisha D; Fulke, Abhay B; Khairnar, Krishna; P. U. MESHRAM; Waman N. PAUNIKAR

    2013-01-01

    This is a comprehensive review of phytoplankton ecology in freshwater lakes of India. A review study was undertaken for the better understanding of the phytoplankton distribution. In broad terms, authors discussed the relations of phytoplankton with factors like lake temperature, sunlight exposure period, sunlight penetration, water pH, wind, transparency, seasonal variations, water characteristics, nutrient enrichment and prey-predator relation in the lakes of India. From the results, author...

  2. The effects of the herbicide atrazine on freshwater snails.

    Science.gov (United States)

    Gustafson, Kyle D; Belden, Jason B; Bolek, Matthew G

    2015-07-01

    Atrazine has been shown to affect freshwater snails from the subcellular to community level. However, most studies have used different snail species, methods, endpoints, and atrazine exposure concentrations, resulting in some conflicting results and limiting our understanding. The goal of this study was to address these concerns by (1) investigating the acute and chronic effects of atrazine on four species of freshwater snails (Biomphalaria glabrata, Helisoma trivolvis, Physa acuta, and Stagnicola elodes) using the same methods, endpoints, and concentrations, and (2) summarizing the current literature pertaining to the effects of atrazine on freshwater snails. We conducted a 48 h acute toxicity test with an atrazine concentration higher than what typically occurs in aquatic environments (1000 µg/L). Additionally, we exposed snails to environmentally relevant atrazine concentrations (0, 0.3, 3, and 30 µg/L) for 28 days and assessed snail survival, growth, and reproduction. We also summarized all known literature pertaining to atrazine effects on freshwater snails. The literature summary suggests snails are often affected by environmentally relevant atrazine concentrations at the subcellular and cellular levels. These effects are typically not transitive to effects on survival, growth, or reproduction at the same concentrations. Our acute exposures corroborate the general trend of no direct effect on snail populations as atrazine did not directly affect the survival of any of the four snail species. Similarly, environmentally relevant concentrations did not significantly affect the survival, growth, or reproduction of any snail species. These results indicate that, in the absence of other possible stressors, the direct effects of environmentally relevant atrazine concentrations may not be realized at the snail population level.

  3. Occurrence of microcystin-producing cyanobacteria in Ugandan freshwater habitats

    Science.gov (United States)

    Okello, William; Portmann, Cyril; Erhard, Marcel; Gademann, Karl; Kurmayer, Rainer

    2011-01-01

    Microcystins (MCs) are cyclic heptapeptides that are the most abundant toxins produced by cyanobacteria in freshwater. The phytoplankton of many freshwater lakes in Eastern Africa is dominated by cyanobacteria. Less is known, however, on the occurrence of MC producers and the production of MCs. Twelve Ugandan freshwater habitats ranging from mesotrophic to hypertrophic conditions were sampled in May and June of 2004 and April of 2008 and were analyzed for their physico-chemical parameters, phytoplankton composition, and MC concentrations. Among the group of the potential MC-producing cyanobacteria, Anabaena (0 - 107 cells ml−1) and Microcystis (103 - 107 cells ml−1) occurred most frequently and dominated in eutrophic systems. A significant linear relationship (n = 31, r2 = 0.38, p < 0.001) between the Microcystis cell numbers and MC concentration (1.3-93 fg of MC cell−1) was observed. Beside [MeAsp3, Mdha7]-MC-RR two new microcystins, [Asp3]-MC-RY and [MeAsp3]-MC-RY were isolated and their constitution assigned by LC-MS2. In order to identify the MC-producing organism in the water samples (i), the conserved aminotransferase domain part of the mcyE gene that is indicative of MC production was amplified by general primers and cloned and sequenced, and (ii), genus-specific primers were used to amplify the mcyE gene of the genera Microcystis, Anabaena, and Planktothrix. Only mcyE genotypes that are indicative of Microcystis sp. were obtained via the environmental cloning approach (337 bp, 96.1%-96.7% similarity to the Microcystis aeruginosa strain PCC7806). Accordingly, only the mcyE primers, which are specific for Microcystis, revealed PCR products. We concluded that Microcystis is the major MC-producer in Ugandan freshwater. PMID:19609871

  4. Phenotypic plasticity and differentiation in an invasive freshwater microalga

    OpenAIRE

    Sassenhagen, Ingrid; Wilken, Susanne; Godhe, Anna; Rengefors, Karin

    2015-01-01

    Recent studies show that both marine and limnic microalgal species often consist of several genetically distinct populations. This is also valid for the nuisance freshwater algae Gonyostomum semen, which originates from acidic, brown water swamp lakes, but can nowadays also be found in clearer lakes with close to neutral pH. We hypothesized that the observed genetic differentiation among G. semen lake populations, reported in earlier studies, is connected to adaptation to local environmental ...

  5. Combined ecological risks of nitrogen and phosphorus in European freshwaters

    OpenAIRE

    Azevedo, L.B.; van Zelm, R.; Leuven, R. S. E. W; Hendriks, A. J; Huijbregts, M.A.J.

    2015-01-01

    Eutrophication is a key water quality issue triggered by increasing nitrogen (N) and phosphorus (P) levels and potentially posing risks to freshwater biota. We predicted the probability that an invertebrate species within a community assemblage becomes absent due to nutrient stress as the ecological risk (ER) for European lakes and streams subjected to N and P pollution from 1985 to 2011. The ER was calculated as a function of species-specific tolerances to NO3 - and total P concentrations a...

  6. An introduction to the freshwater animal diversity assessment (FADA) project

    OpenAIRE

    Balian, E. V.; Segers, H.; Lévêque, Christian; Martens, K.

    2008-01-01

    The Freshwater Animal Diversity Assessment (FADA) project aims at compiling an overview of genus- and species-level diversity of animals in the continental, aquatic ecosystems of the world. It is a collective effort of 163 experts, and presents 59 articles treating the diversity and endemism of different animal taxa, ranging from microscopic worms to mammals, at global and regional scales. Given their structural importance, an article on macrophytes is also added. Here, we give an overview of...

  7. EUSTRONGYLIDOSIS’ OCCURENCE IN FRESHWATER FISH FROM THE DANUBIAN DELTA AREA

    OpenAIRE

    LAURA URDES; MARIUS HANGAN; CRISTIANA DIACONESCU; DANIELA IANIłCHI; VLAD SERAFIM

    2013-01-01

    The groups of nemathodes who infect fish has been studyied since it has been noticed that these parasites infect a large variety of organisms, being widespread all over the world, in both freshwater and marine species. The aim of this study was to investigate the infections with Eustrongylides sp. in perch, pike, pikeperch, sheat fish, and sun perch, fished into the natural Romanian's lakes, around the Danubian Delta. Our study started on October 2005 and ended on March 2008. The fish have be...

  8. Gastrotricha: A Marine Sister for a Freshwater Puzzle

    OpenAIRE

    M Antonio Todaro; Matteo Dal Zotto; Ulf Jondelius; Rick Hochberg; Hummon, William D.; Tobias Kånneby; Carlos E. F. Rocha

    2012-01-01

    BACKGROUND: Within an evolutionary framework of Gastrotricha Marinellina flagellata and Redudasys fornerise bear special interest, as they are the only Macrodasyida that inhabit freshwater ecosystems. Notwithstanding, these rare animals are poorly known; found only once (Austria and Brazil), they are currently systematised as incertae sedis. Here we report on the rediscovery of Redudasys fornerise, provide an account on morphological novelties and present a hypothesis on its phylogenetic rela...

  9. Freshwater, Saltwater, and Deepwater: Efficient Market Hypothesis versus Behavioral Finance.

    OpenAIRE

    Wójcik, Dariusz; Kreston, Nicholas; McGill, Sarah

    2012-01-01

    The efficient market hypothesis (EMH) and behavioral finance (BF) form the blame-hope axis of the ongoing soul-searching exercise in economics, which frequently refers to the 'Chicago School' and the ideological division between 'freshwater' and 'saltwater' universities. Citation analysis for 1965-2010 shows that these simple geographical anecdotes do not apply, as saltwater economists heavily cited the seminal EMH papers from the beginning, and vice versa. BF lags behind EMH in terms of the ...

  10. A Study on Competitiveness of Sea Transport by Comparing International Transport Routes between Korea and EU

    Directory of Open Access Journals (Sweden)

    Dae-seop Moon

    2015-03-01

    Route 1 was found the most competitive, and Route 5, the most widely used sea way was ranked the lowest. In addition, the new transport routes, Route 1 and 6 are shown to be more competitive than the currently available routes, Route 2, 3 and 4. However, these routes need national level supports (rail construction for Route 1 and subsidy plan for Route 6 for the commercial use in the future.

  11. Auction-based schemes for multipath routing in selfish networks

    OpenAIRE

    Zhou, H; Leung, KC; Li, VOK

    2013-01-01

    We study multipath routing with traffic assignment in selfish networks. Based on the Vickrey-Clarke-Groves (VCG) auction, an optimal and strategy-proof scheme, known as optimal auction-based multipath routing (OAMR), is developed. However, OAMR is computationally expensive and cannot run in real time when the network size is large. Therefore, we propose sequential auction-based multipath routing (SAMR). SAMR handles routing requests sequentially using some greedy strategies. In particular, wi...

  12. The Efficiency of Constraint Based Routing in MPLS Networks

    Directory of Open Access Journals (Sweden)

    Martin Medvecky

    2011-01-01

    Full Text Available The paper presents the simulation results and evaluates the efficiency of constraint base routing algorithms used in MPLS network from the point of their usability in Next Generation Networks. The efficiency of constraint based routing is evaluated according following criteria: optimal path selection, routing priority of traffic flows selected for constraint routing and bandwidth allocation by MAM or RDM bandwidth constraints models.

  13. Educational routes in tourism of Novohradské hory mountains

    OpenAIRE

    CVACHOVÁ, Klára

    2011-01-01

    The chief aim of this bachelor work is to asses current situation to usage of educational routes in tourism of Novohradské hory mountains. The first aim is to construct dokumentation of educational routes in choice area. On educational routes was executed the personal research.The second aim is to asses the relation of current visitors to educational routes in certain area. We came by nformation about relation of visitors through the questionaire.The last aim introduces identification of them...

  14. Energy efficient cluster-based routing in wireless sensor networks

    OpenAIRE

    Zeghilet, Houda; Badache, Nadjib; Maimour, Moufida

    2009-01-01

    Because of the lack of a global naming scheme, routing protocols in sensor networks usually use flooding to select paths and deliver data. This process although simple and effective, is very costly in terms of energy consumption, an important design issue in sensor networks routing protocols. Cluster-based routing is one solution to save energy. In this paper, we propose a combination of an improved clustering algorithm and directed diffusion, a well-known data-centric routing paradigm in sen...

  15. Multipath Routing with Erasure Coding for Wireless Sensor Networks

    OpenAIRE

    Wu, Jian; Dulman, Stefan; Havinga, Paul; Nieberg, Tim

    2004-01-01

    Multipath routing algorithm in wireless sensor networks (WSN) increase the reliability of the system at the cost of significantly increased traffic. This paper introduces a splitted multipath routing scheme to improve the reliability of data routing in WSN by keeping the traffic at a low level. Our proposed on-demand multipah routing algorithm offers the data source several paths to any destination. It is used in combination with a data splitting method based on Erasure Coding. The algorithms...

  16. An Efficient Bypassing Void Routing Algorithm for Wireless Sensor Network

    OpenAIRE

    2015-01-01

    Since the sensor node’s distribution in a wireless sensor network (WSN) is irregular, geographic routing protocols using the greedy algorithm can cause local minima problem. This problem may fail due to routing voids and lead to failure of data transmission. Based on the virtual coordinate mapping, this paper proposes an efficient bypassing void routing protocol to solve the control packet overhead and transmission delay in routing void of WSN, which is called EBVRPVCM. The basic idea is to t...

  17. Reactive and proactive routing in labelled optical burst switching networks

    OpenAIRE

    Klinkowski, Miroslaw; Careglio, Davide; Solé Pareta, Josep

    2009-01-01

    Optical burst switching architectures without buffering capabilities are sensitive to burst congestion. The existence of a few highly congested links may seriously aggravate the network throughput. Proper network routing may help in congestion reduction. The authors focus on adaptive routing strategies to be applied in labelled OBS networks, that is, with explicit routing paths. In particular, two isolated alternative routing algorithms that aim at network performance improvement because o...

  18. DNA display I. Sequence-encoded routing of DNA populations.

    OpenAIRE

    Halpin, David R; Pehr B Harbury

    2004-01-01

    Recently reported technologies for DNA-directed organic synthesis and for DNA computing rely on routing DNA populations through complex networks. The reduction of these ideas to practice has been limited by a lack of practical experimental tools. Here we describe a modular design for DNA routing genes, and routing machinery made from oligonucleotides and commercially available chromatography resins. The routing machinery partitions nanomole quantities of DNA into physically distinct subpools ...

  19. An Approach In Optimization Of Ad-Hoc Routing Algorithms

    Directory of Open Access Journals (Sweden)

    Sarvesh Kumar Sharma

    2012-06-01

    Full Text Available In this paper different optimization of Ad-hoc routing algorithm is surveyed and a new method using training based optimization algorithm for reducing the complexity of routing algorithms is suggested. A binary matrix is assigned to each node in the network and gets updated after each data transfer using the protocols. The use of optimization algorithm in routing algorithm can reduce the complexity of routing to the least amount possible.

  20. Traffic modifications on Routes Rutherford, Democrite and Fermi

    CERN Multimedia

    2015-01-01

    The GS Department would like to inform you that until the end of December, the construction of Building 245 will result in the following traffic modifications: Traffic on Route Rutherford will be partially restricted in front of the construction site, Traffic on Route Democrite will be one-way towards Route Rutherford. Also, please note that due to construction work in front of Building 377, Route Fermi will be closed from Wednesday, 10 June until Friday, 7 August. Thank you for your understanding.