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Sample records for fish ladder design

  1. New Concepts in Fish Ladder Design, Volume III of IV, Assessment of Fishway Development and Design, 1982-1983 Final Report.

    Powers, Patrick D.; Orsborn, John F.

    1985-08-01

    This volume covers the broad, though relatively short, historical basis for this project. The historical developments of certain design features, criteria and research activities are traced. Current design practices are summarized based on the results of an international survey and interviews with agency personnel and consultants. The fluid mechanics and hydraulics of fishway systems are discussed. Fishways (or fishpasses) can be classified in two ways: (1) on the basis of the method of water control (chutes, steps (ladders), or slots); and (2) on the basis of the degree and type of water control. This degree of control ranges from a natural waterfall to a totally artificial environment at a hatchery. Systematic procedures for analyzing fishways based on their configuration, species, and hydraulics are presented. Discussions of fish capabilities, energy expenditure, attraction flow, stress and other factors are included.

  2. Selectivity of fish ladders: a bottleneck in Neotropical fish movement

    Carlos Sérgio Agostinho

    2007-01-01

    Full Text Available Although dozens of fish ladders have been constructed at dams of Brazilian reservoirs, there are few studies evaluating their efficiency as a tool for the conservation of Neotropical ichthyofauna, especially for migratory species. Therefore, the present study evaluated the selectivity of the species that entered and ascended the fish ladder located next to Lajeado Dam (Luis Eduardo Magalhães Hydroelectric Power Plant on the Tocantins River. Samples were taken monthly from November, 2002 through October, 2003, in the resting pools of the ladder, using cast nets, and in the downstream stretch, using gillnets. The selectivity of the ladder in attracting fish was evaluated by comparing the occurrence, relative abundance, dominance and the congruence of abundance ranks of migratory and non-migratory species in the ladder and in the stretch of river immediately downstream. Species richness and fish abundance in the resting pools were used to evaluate selectivity along the ladder. The effects on selectivity by temporal variations in water level downriver and maximum flow velocity in the fish ladder were also analyzed. Out of the 130 species recorded downriver, 62.3% were caught in the ladder, and migratory species were clearly favored. However, more than 2/3 of the catch belonged to only three species (Rhaphiodon vulpinus, Psectrogaster amazonica and Oxydoras niger. Although the majority of the species that entered the ladder were able to reach its top, there was a sharp reduction in abundance of individuals towards the top. Temporal variations in the water level below the dam influenced richness and abundance of fish concentrated downstream and in the ladder, with lower values during periods of low water. In the ladder, a maximum flow velocity of 2.3 m/s, although also selective, proved to be more appropriate for fish ascension than a velocity of 2.8 m/s. It was concluded that the entry and ascension of the fish in the ladder were not congruent with

  3. New Concepts in Fish Ladder Design, Part I of IV, Summary Report, 1982-1984 Final Project Report.

    Orsborn, John F.

    1985-08-01

    The report looks at the most active periods of fishway research since 1938 as background for a project to apply fundamental fluid and bio-mechanics to fishway design, and develop more cost effective fish passage facilities with primary application to small scale hydropower facilities. Also discussed are new concepts in fishway design, an assessment of fishway development and design, and an analysis of barriers to upstream migration. (ACR)

  4. Designer Fish.

    Hall, William R., Jr.

    1990-01-01

    Described is an activity in which students are asked to design a fish that would survive in a natural system. A project to computerize the activity is discussed. The development of this artificial intelligence software is detailed. (CW)

  5. Fish-ladders - future and new projects for prepared small HPP

    During a long term preparation of the small HPP, the demonstration of our highest environmental tolerance is to propose the most suitable technical installation, so called the fish ladder in order to overcome barrier of intake structure in accordance with the needs and requires. (author)

  6. Changes in selection and evolutionary responses in migratory brown trout following the construction of a fish ladder

    Haugen, Thrond Oddvar; Aass, Per; Stenseth, Nils Christian; Vøllestad, Leif Asbjørn

    2008-01-01

    Brown trout (Salmo trutta) are extensively harvested and its habitat highly influenced by human encroachments. Using a 40-year time series of mark–recapture data we estimate vital rates for a piscivorous trout population. This population spawns upstream of a waterfall, which historically acted as a migration barrier for smaller trout. In 1966, the waterfall was dammed and a fish ladder constructed. All fish ascending the fish ladder were individually tagged and measured for a variety of trait...

  7. New Concepts in Fish Ladder Design, Volume II of IV, Results of Laboratory and Field Research on New Concepts in Weir and Pool Fishways, 1982-1984 Final Project Report.

    Aaserude, Robert G.; Orsborn, John F.

    1985-08-01

    A comprehensive review of fishway design practice led to new design concepts that had previously been untested. This concept was based on the observation that fish can be stimulated to leap when presented with certain hydraulic conditions. A laboratory test program was conducted to develop this concept into a new fishway configuration. Field testing revealed that components of the new design improved fish passage. Verification of the initial premise that fish can be stimulated to leap needs further study.

  8. Selection of an experimental fish ladder located at the dam of the Itaipu Binacional, Paraná River, Brazil

    Domingo Rodriguez Fernandez

    2004-08-01

    Full Text Available The specific selection of a weir and orifice type experimental fish ladder in the dam of the Itaipu Reservoir (Paraná River was evaluated by samplings in the river downstream and at two points along the ladder (at heights of 10 m and 27 m during 28 months. Among the 65 species recorded in the river (immediate downstream of the dam, 27 were captured on the ladder. The species that showed highest density on the ladder, the majority migratory, were moderately, or only slightly, abundant downstream. Among the most abundant species downstream, only one, non-migratory, was recorded in the ladder. The structure presented a negative selection in relation to large migratory pimelodids that might be overcome by enlarging the scale of its design. The sampling demonstrated a moderate selection of species along the ladder and its hydraulic model proved satisfactory regarding the attraction and efficient ascent of the fishes.A seleção específica de uma escada de peixes do tipo seqüência de tanques, com passagem de fundo (tipo weir and orifice, na barragem da hidrelétrica de Itaipu (rio Paraná, foi avaliada através de amostragens no rio a jusante (amostragem trimestral em 1997 e em dois pontos ao longo da escada (10 e 27m de altura; nov/94 a jan/97 e nov/94 a fev/97, respectivamente. Das 65 espécies registradas no rio imediatamente a jusante da barragem, 27 foram capturadas na escada. As espécies com maior densidade na escada, em sua maioria migradoras, tiveram abundância moderada ou baixa a jusante. Entre as mais abundantes a jusante, apenas uma, não migradora, foi registrada na escada. A escada apresentou seleção negativa aos grandes pimelodídeos migradores que pode ser superada com a ampliação na escala do projeto. As amostragens evidenciaram baixa seletividade específica ao longo da escada, sendo seu modelo hidráulico satisfatório na atração e eficiente na ascensão de peixes.

  9. Utilization of the fish ladder at the Engenheiro Sergio Motta Dam, Brazil, by long distance migrating potamodromous species

    Sérgio Makrakis

    2007-01-01

    Full Text Available Utilization of the fish ladder installed at the Engenheiro Sergio Motta Dam (also known as Porto Primavera on the Paraná River, Southern Brazil, by long-distance migrating potamodromous species (sampling Protocol I, and ascending and descending movements (Protocol II were evaluated. Three pools along the fish ladder (designated as lower, middle, and upper were sampled monthly between December, 2004 and March, 2005 to determine the abundance of species in the ladder. The ascending and descending movements of the species in the ladder were also analyzed in the same period. In the samples for both protocols, 37 species representing 17 families and 5 orders (Characiformes, Siluriformes, Perciformes, Gymnotiformes, and Myliobatiformes were recorded. Characiformes were represented by 21 species. Long- distance migratory species (11 species predominated in the ladder (60% of the total number of individuals, with high abundance of Rhinelepis aspera (5645 individuals. For protocol I, mean abundance varied greatly among the months and pools, with lowest values in December and March for all pools, and highest in January for the lower pool due to high capture of R. aspera. Fish abundance declined from the lower to the upper pool, especially for R. aspera and Rhaphiodon vulpinus. For Protocol II, 17 species were recorded ascending the ladder, where Astyanax altiparanae and Leporinus friderici were the most abundant species (684 and 111 individuals, respectively. However, 18 species showed descending movements, with high captures of Metynnis maculatus and A. altiparanae (339 and 319 individuals, respectively. Twelve species (52% moved in both directions, and among the seven migratory species sampled, four were recorded ascending and descending, and three species only ascending the ladder. The fish ladder appears to selectively favor species with high swimming capabilities. A discussion is presented on the requirements for future research on attraction to the

  10. Indirect effects of impoundment on migrating fish: temperature gradients in fish ladders slow dam passage by adult Chinook salmon and steelhead.

    Christopher C Caudill

    Full Text Available Thermal layering in reservoirs upstream from hydroelectric dams can create temperature gradients in fishways used by upstream migrating adults. In the Snake River, Washington, federally-protected adult salmonids (Oncorhynchus spp. often encounter relatively cool water in dam tailraces and lower ladder sections and warmer water in the upstream portions of ladders. Using radiotelemetry, we examined relationships between fish passage behavior and the temperature difference between the top and bottom of ladders (∆T at four dams over four years. Some spring Chinook salmon (O. tshawytscha experienced ∆T ≥ 0.5 °C. Many summer and fall Chinook salmon and summer steelhead (O. mykiss experienced ∆T ≥ 1.0 °C, and some individuals encountered ΔT > 4.0°C. As ΔT increased, migrants were consistently more likely to move down fish ladders and exit into dam tailraces, resulting in upstream passage delays that ranged from hours to days. Fish body temperatures equilibrated to ladder temperatures and often exceeded 20°C, indicating potential negative physiological and fitness effects. Collectively, the results suggest that gradients in fishway water temperatures present a migration obstacle to many anadromous migrants. Unfavorable temperature gradients may be common at reservoir-fed fish passage facilities, especially those with seasonal thermal layering or stratification. Understanding and managing thermal heterogeneity at such sites may be important for ensuring efficient upstream passage and minimizing stress for migratory, temperature-sensitive species.

  11. Changes in selection and evolutionary responses in migratory brown trout following the construction of a fish ladder.

    Haugen, Thrond Oddvar; Aass, Per; Stenseth, Nils Christian; Vøllestad, Leif Asbjørn

    2008-05-01

    Brown trout (Salmo trutta) are extensively harvested and its habitat highly influenced by human encroachments. Using a 40-year time series of mark-recapture data we estimate vital rates for a piscivorous trout population. This population spawns upstream of a waterfall, which historically acted as a migration barrier for smaller trout. In 1966, the waterfall was dammed and a fish ladder constructed. All fish ascending the fish ladder were individually tagged and measured for a variety of traits. The fish ladder overall favoured access to upstream spawning areas for middle-sized trout, resulting in stabilizing selection acting on size at spawning. Over time, natural and fishing mortality have varied, with fishing mortality generally decreasing and natural mortality increasing. The average and, particularly, variance in size-at-first-spawning, and growth rates during the first years of lake residence have all decreased over the 1966-2003 period. These changes are all consistent with a shift from directional to stabilizing selection on age and size at spawning. Estimated rates of phenotypic change are relatively high, in particular for size at first spawning, adding further support for the growing notion that human interference may lead to rapid life-history trait evolution. PMID:25567634

  12. Evaluation of fish passage through the Igarapé Dam fish ladder (rio Paraopeba, Brazil, using marking and recapture

    Carlos Bernardo Mascarenhas Alves

    2007-01-01

    Full Text Available Rio Paraopeba, a tributary of rio São Francisco, has a six-meter high dam, built in 1978 to divert water to the Igarapé Thermal Power Plant. In 1994, a fish ladder was built at this dam. The results of a marking and recapture program carried out along rio Paraopeba between 1997 and 2001 are described, using information from fish community studies conducted at ten sampling stations between 1994 and 1997. These investigations showed the presence of at least 91 species in the river. During four rainy seasons between 1997 and 2000, fish were caught downstream of the dam, marked with external plastic tags, and immediately released at the same site. The objective was to evaluate fish passage through the ladder, based on recapture information from artisanal and sport fishermen. A total of 3,642 specimens were marked, adding up to a biomass of approximately 1.33 tons. Twenty-six species were used, representing 28.5% of the total recorded richness (91 species. Maximum recorded tag retention time was 10 months. Total recapture rate was 4.37% in four years, reaching 5.75% in the last period (2000-2001. Of all recaptured specimens, 14.0% were caught upstream of the dam, evidencing passage through the ladder. The specimens recaptured upstream of the dam belonged to three species: piau-verdadeiro (Leporinus obtusidens, mandi-amarelo (Pimelodus maculatus and curimatá-pioa (Prochilodus costatus. These species showed linear home ranges of 15.4, 81.5 and 232.0 km, respectively. Most recaptures occurred immediately downstream of the dam, one of the most intensely fished stretches of rio Paraopeba.Desde 1978, o rio Paraopeba, um afluente do rio São Francisco, tem uma barragem de 6 metros de altura para desvio de água para a Usina Térmica de Igarapé. Em 1994, uma escada para peixes foi construída nessa barragem. Os resultados de um programa de marcação e recaptura realizado entre 1997 e 2001 são descritos, utilizando dados prévios de estudos das

  13. Diel variation in the ascent of fishes up an experimental fish ladder at Itaipu Reservoir: fish size, reproductive stage and taxonomic group influences

    Domingo Rodriguez Fernandez

    2007-01-01

    Full Text Available In this study, we evaluated the fish ascent in the experimental ladder at Itaipu Reservoir (Paraná State, Brazil, in relation to diel variation, fish size, reproductive stages and species composition. The study was carried out from October, 1995 to February, 1996 and from November, 1996 to January, 1997 at two points on the ladder (boxes at heights of 10 and 27 m. Twenty-two species were recorded, and Prochilodus lineatus, Pimelodus maculatus, Leporinus obtusidens, Schizodon borellii and Leporinus friderici accounted for 86.6 % of the total catch. Fish length did not differ between diel periods and boxes. On the other hand, fish abundance of the main species was significantly influenced by box position, reproductive stage and diel period. The higher box showed lower abundance, suggesting some selectivity in ascension. The ability to ascend the ladder did not show any relationship with reproductive migration, since non-reproductive adults comprised most of the catch. An interesting finding is that the major taxonomic groups showed specific diel preferences in ascending the ladder: Characiformes ascended the ladder predominantly during daylight, whereas Siluriformes migrated at night. These results emphasize how complex ladders are as management tools, and stress the need to acquire information on several aspects as a condition to achieve conservation goals.Nesse estudo, a transposição de peixes na escada experimental do reservatório de Itaipu (Paraná, Brasil foi avaliada em relação à variação diária, tamanho dos peixes, estágios reprodutivos e a composição das espécies. O estudo foi conduzido de Outubro de 1995 a Fevereiro de 1996, e de Novembro de 1996 a Janeiro de 1997, em dois trechos da escada (caixas a 10 e 27 m de altura. Vinte e duas espécies foram registradas, e Prochilodus lineatus, Pimelodus maculatus, Leporinus obtusidens, Schizodon borellii e Leporinus friderici compuseram 86,6% das capturas. O tamanho dos peixes n

  14. Comparing on site human and video counts at Igarapava fish ladder, south eastern Brazil

    Mark D. Bowen

    2006-06-01

    Full Text Available On site human observations and video images were collected and compared at the window of the Igarapava Dam fish ladder (IDFL, rio Grande , Southeastern Brazil, between March 1st and June 30th, 2004. We conducted four experiments with two humans (Observer 1 and Observer 2 observing fish passage in the IDFL window while a Sony 3CCD video camera (Observer 3 recorded fish passage at the same time. Experiments, each one hour in length, were distributed throughout the diel cycle using full spectrum lights. We identified fish species, the number of individuals for each species, and the real time that they passed. Counts from each human observer were compared to the video counts. The fish species most commonly observed in the window were - curimba (Prochilodus lineatus, mandi-amarelo (Pimelodus maculatus, piau-três-pintas (Leporinus friderici and ferreirinha (Leporinus octofasciatus. The number of species and individuals were indistinguishable for the three observers. But, the number of species and individuals were significantly different among experiments. Thus, the three observers register the same number of species and count the same number of individuals even when these two response variables differ significantly among experiments. Based on these results, we concluded that the video count was an accurate method to assess fish passage at the IDFL.Observações in loco e vídeo filmagens foram coletadas na janela da escada de peixes da UHE Igarapava (EPUG, rio Grande, sudeste do Brasil, entre 1º de março e 30 junho de 2004. Realizaram-se quatro experimentos com dois observadores humanos (Observador 1 e Observador 2 que observaram a passagem de peixes na janela da EPUG enquanto uma vídeo câmera Sony 3CCD (Observador 3 registrou simultaneamente a passagem de peixes. Os dois observadores humanos registraram in situ a passagem de peixes no visor da escada enquanto a câmera os filmava ao mesmo tempo. Os experimentos, cada um com uma hora de dura

  15. Assessments to determine the effect of current and alternate ladder operations on brood stock collection and behavior of hatchery fall Chinook Salmon at Spring Creek National Fish Hatchery during 2003-2005

    US Fish and Wildlife Service, Department of the Interior — Spring Creek National Fish Hatchery traditionally operates an adult ladder, without closure, from the start of the tule fall Chinook salmon run in late August until...

  16. Fish passage post-construction issues: analysis of distribution, attraction and passage efficiency metrics at the Baguari Dam fish ladder to approach the problem

    Luiz Gustavo Martins da Silva; Lorena Bettinelli Nogueira; Bruno Pereira Maia; Lucas Borges de Resende

    2012-01-01

    Fish passages are considered the oldest management tool used to minimize the impact of blocking fish migratory routes by hydroelectric power plants. However, fish passages are being installed without specific criteria in Brazil, with severe consequences to the conservation of the local fish fauna. Therefore, basic data gathered for fish passages already constructed could contribute to define operational rules, in addition to offer subsidies to decision-making and design of future facilities. ...

  17. Voegelin's Ladder

    Nathan Harter

    2006-06-01

    Full Text Available Leadership has non-logical aspects. One of these is spirituality. Voegelin’s Ladder provides a context for studying spirituality as a part of leadership. What it reveals is that spirituality arises at the intersection of the human with the divine. Spirituality expresses itself as purpose and aspiration, which a leader embodies.

  18. The latrine ownership ladder

    Obeng, Peter Appiah; Keraita, Bernard; Oduro-Kwarteng, Sampson;

    2015-01-01

    Purpose – The purpose of this paper is to present the latrine ownership ladder as a conceptual policy framework to enhance sanitation uptake in low-income peri-urban areas. Design/methodology/approach – The paper draws from literature and a case study in a Ghanaian peri-urban community to highlig...

  19. Construction and test of the first Belle II SVD ladder implementing the origami chip-on-sensor design

    Irmler, C.; Adamczyk, K.; Aihara, H.; Angelini, C.; Aziz, T.; Babu, V.; Bacher, S.; Bahinipati, S.; Barberio, E.; Baroncelli, Ti.; Baroncelli, To.; Basith, A. K.; Batignani, G.; Bauer, A.; Behera, P. K.; Bergauer, T.; Bettarini, S.; Bhuyan, B.; Bilka, T.; Bosi, F.; Bosisio, L.; Bozek, A.; Buchsteiner, F.; Casarosa, G.; Ceccanti, M.; Červenkov, D.; Chendvankar, S. R.; Dash, N.; Divekar, S. T.; Doležal, Z.; Dutta, D.; Forti, F.; Friedl, M.; Frühwirth, R.; Hara, K.; Higuchi, T.; Horiguchi, T.; Ishikawa, A.; Jeon, H. B.; Joo, C.; Kandra, J.; Kang, K. H.; Kato, E.; Kawasaki, T.; Kodyš, P.; Kohriki, T.; Koike, S.; Kolwalkar, M. M.; Kvasnička, P.; Lanceri, L.; Lettenbicher, J.; Maki, M.; Mammini, P.; Mayekar, S. N.; Mohanty, G. B.; Mohanty, S.; Morii, T.; Nakamura, K. R.; Natkaniec, Z.; Negishi, K.; Nisar, N. K.; Onuki, Y.; Ostrowicz, W.; Paladino, A.; Paoloni, E.; Park, H.; Pilo, F.; Profeti, A.; Rao, K. K.; Rashevskaia, I.; Rizzo, G.; Rozanska, M.; Sandilya, S.; Sasaki, J.; Sato, N.; Schultschik, S.; Schwanda, C.; Seino, Y.; Shimizu, N.; Stypula, J.; Suzuki, J.; Tanaka, S.; Tanida, K.; Taylor, G. N.; Thalmeier, R.; Thomas, R.; Tsuboyama, T.; Uozumi, S.; Urquijo, P.; Vitale, L.; Volpi, M.; Watanuki, S.; Watson, I. J.; Webb, J.; Wiechczynski, J.; Williams, S.; Würkner, B.; Yamamoto, H.; Yin, H.; Yoshinobu, T.

    2016-01-01

    The Belle II Silicon Vertex Detector comprises four layers of double-sided silicon strip detectors (DSSDs), consisting of ladders with two to five sensors each. All sensors are individually read out by APV25 chips with the Origami chip-on-sensor concept for the central DSSDs of the ladders. The chips sit on flexible circuits that are glued on the top of the sensors. This concept allows a low material budget and an efficient cooling of the chips by a single pipe per ladder. We present the construction of the first SVD ladders and results from precision measurements and electrical tests.

  20. Construction and test of the first Belle II SVD ladder implementing the origami chip-on-sensor design

    The Belle II Silicon Vertex Detector comprises four layers of double-sided silicon strip detectors (DSSDs), consisting of ladders with two to five sensors each. All sensors are individually read out by APV25 chips with the Origami chip-on-sensor concept for the central DSSDs of the ladders. The chips sit on flexible circuits that are glued on the top of the sensors. This concept allows a low material budget and an efficient cooling of the chips by a single pipe per ladder. We present the construction of the first SVD ladders and results from precision measurements and electrical tests

  1. Hood River and Pelton Ladder monitoring and evaluation project and Hood River fish habitat project : annual progress report 1999-2000.; ANNUAL

    The Hood River subbasin is home to four species of anadromous salmonids: chinook salmon (Oncorhynchus tshawytscha), coho salmon (Oncorhynchus kisutch), steelhead (Oncorhynchus mykiss), and sea run cutthroat trout (Salmo clarki). Indigenous spring chinook salmon were extirpated during the late 1960's. The naturally spawning spring chinook salmon currently present in the subbasin are progeny of Deschutes stock. Historically, the Hood River subbasin hatchery steelhead program utilized out-of-basin stocks for many years. Indigenous stocks of summer and winter steelhead were listed in March 1998 by National Marine Fisheries Service (NMFS) under the Endangered Species Act (ESA) as a ''Threatened'' Species along with similar genetically similar steelhead in the Lower Columbia Basin. This annual report summarizes work for two consecutive contract periods: the fiscal year (FY) 1999 contract period was 1 October, 1998 through 30 September, 1999 and 1 October, 1999 through 30 September, 2000 for FY 2000. Work implemented during FY 1999 and FY 2000 included (1) acclimation of hatchery spring chinook salmon and hatchery summer and winter steelhead smolts, (2) spring chinook salmon spawning ground surveys on the West Fork Hood River (3) genetic analysis of steelhead and cutthroat[contractual service with the ODFW], (4) Hood River water temperature studies, (5) Oak Springs Hatchery (OSH) and Round Butte Hatchery (RBH) coded-wire tagging and clipping evaluation, (6) preparation of the Hood River Watershed Assessment (Coccoli et al., December 1999) and the Fish Habitat Protection, Restoration, and Monitoring Plan (Coccoli et al., February 2000), (7) project implementation of early action habitat protection and restoration projects, (8) Pelton Ladder evaluation studies, (9) management oversight and guidance to BPA and ODFW engineering on HRPP facilities, and (10) preparation of an annual report summarizing project objectives for FY 1999 and FY 2000

  2. Hood River and Pelton Ladder Monitoring and Evaluation Project and Hood River Fish Habitat Project : Annual Progress Report 1999-2000.

    Lambert, Michael B.; McCanna, Joseph P.; Jennings, Mick

    2001-02-01

    The Hood River subbasin is home to four species of anadromous salmonids: chinook salmon (Oncorhynchus tshawytscha), coho salmon (Oncorhynchus kisutch), steelhead (Oncorhynchus mykiss), and sea run cutthroat trout (Salmo clarki). Indigenous spring chinook salmon were extirpated during the late 1960's. The naturally spawning spring chinook salmon currently present in the subbasin are progeny of Deschutes stock. Historically, the Hood River subbasin hatchery steelhead program utilized out-of-basin stocks for many years. Indigenous stocks of summer and winter steelhead were listed in March 1998 by National Marine Fisheries Service (NMFS) under the Endangered Species Act (ESA) as a ''Threatened'' Species along with similar genetically similar steelhead in the Lower Columbia Basin. This annual report summarizes work for two consecutive contract periods: the fiscal year (FY) 1999 contract period was 1 October, 1998 through 30 September, 1999 and 1 October, 1999 through 30 September, 2000 for FY 2000. Work implemented during FY 1999 and FY 2000 included (1) acclimation of hatchery spring chinook salmon and hatchery summer and winter steelhead smolts, (2) spring chinook salmon spawning ground surveys on the West Fork Hood River (3) genetic analysis of steelhead and cutthroat [contractual service with the ODFW], (4) Hood River water temperature studies, (5) Oak Springs Hatchery (OSH) and Round Butte Hatchery (RBH) coded-wire tagging and clipping evaluation, (6) preparation of the Hood River Watershed Assessment (Coccoli et al., December 1999) and the Fish Habitat Protection, Restoration, and Monitoring Plan (Coccoli et al., February 2000), (7) project implementation of early action habitat protection and restoration projects, (8) Pelton Ladder evaluation studies, (9) management oversight and guidance to BPA and ODFW engineering on HRPP facilities, and (10) preparation of an annual report summarizing project objectives for FY 1999 and FY 2000.

  3. Understanding the Behaviour of Infinite Ladder Circuits

    Ucak, C.; Yegin, K.

    2008-01-01

    Infinite ladder circuits are often encountered in undergraduate electrical engineering and physics curricula when dealing with series and parallel combination of impedances, as a part of filter design or wave propagation on transmission lines. The input impedance of such infinite ladder circuits is derived by assuming that the input impedance does…

  4. 29 CFR 1910.26 - Portable metal ladders.

    2010-07-01

    ... Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR OCCUPATIONAL SAFETY AND HEALTH STANDARDS Walking-Working Surfaces § 1910.26 Portable metal ladders. (a... are designed as a one-man working ladder based on a 200-pound load. (iii) The ladder base section...

  5. A career ladder for radiological technologists.

    Gillan, G D; Pearce, J; Rutherford, M; Walters, L

    1984-03-01

    A career ladder is a mechanism for employee progression within a chosen field. This paper describes the design and implementation of such a system in a large community radiology department. The career ladder system included integrated job descriptions, salary scales and evaluation procedures for radiology technologists. The implementation of this new system had a positive effect on employee morale manifested in decreased turnover, less absenteeism and increased job satisfaction. PMID:10265983

  6. Understanding the behaviour of infinite ladder circuits

    Infinite ladder circuits are often encountered in undergraduate electrical engineering and physics curricula when dealing with series and parallel combination of impedances, as a part of filter design or wave propagation on transmission lines. The input impedance of such infinite ladder circuits is derived by assuming that the input impedance does not change when a new block of impedance is added. However, the impedance derived from this assumption may lead to incorrect conclusions if it is not treated carefully. Sometimes, in the literature, the input impedance behaviour of infinite ladder circuits is referred to as a paradox, leaving students and educators in doubt. This study intends to clarify this confusion and help to better comprehend the behaviour of the input impedance of infinite ladder circuits

  7. Mechanical design and implementation of a new biomimetic robot fish

    Wang Long; Cao Zhiqiang; Tan Min; Wang Shuo

    2007-01-01

    A mechanical design method of robot fish is introduced in this paper.Based on this method an antonomous 3-Dimension(3D)locomotion robot fish with two pectoral fins and a caudal fin is developed.The pectoral fin mechanism has 3 degrees of freedom(3-DOFs),which enables the robot fish to realize yawing and pitching motions by controlling two pectoral fins.And the caudal fin mechanism is designed based on fish body wave curve fitting.The forward velocity can be adjusted by changing the caudal mechanism's oscillating frequency.Finally a physical implementation of the robot fish and experimental results are given.

  8. Theory of Double Ladder Lumped Circuits With Degenerate Band Edge

    Sloan, Jeff; Capolino, Filippo

    2016-01-01

    Conventional periodic LC ladder circuits exhibit a regular band edge between a pass and a stop band. Here for the first time we develop the theory of simple yet unconventional double ladder circuits exhibiting a special degeneracy condition referred to as degenerate band edge (DBE). This special DBE condition is associated with four independent eigenstates of the double ladder that coalesce into a single one when the operative frequency coincides with the DBE one. In particular, we show that double ladder resonators may exhibit giant loaded quality factor near the DBE and stable resonance frequency against load variations. These two properties in the proposed circuit are superior to the analogous properties in single ladder circuits. Our proposed analysis leads to analytic expressions for all circuit quantities thus providing insight into the very complex behavior near points of degeneracy in periodic circuits; and provides a design procedure for the use of such double ladder in practical applications. Intere...

  9. The Design and Implementation of a Biomimetic Robot Fish

    Chao Zhou

    2008-11-01

    Full Text Available In this paper, a novel design of a biomimetic robot fish is presented. Based on the propulsion and maneuvering mechanisms of real fishes, a tail mechanical structure with cams and connecting rods for fitting carangiform fish body wave is designed, which provides the main propulsion. Two pectoral fins are mounted, and each pectoral fin can flap separately and rotate freely. Coordinating the movements of the tail and pectoral fins, the robot fish can simulate the movements of fishes in water. In order to obtain the necessary environmental information, several kinds of sensors (video, infrared, temperature, pressure and PH value sensors were mounted. Finally, the realization of the robot fish is presented.

  10. Baryons and ladders

    By formal manipulation of the QCD functional integral we arrive at a relativistic low energy effective theory of non-local color singlet mesons and baryons, which at tree level sums up ladders of effective glue exchange between constituent quarks. (orig.)

  11. Design of a re-entrant double-staggered ladder circuit for V-band coupled-cavity traveling-wave tubes

    Liu Yang; Xu Jin; Lai Jian-Qiang; Xu Xiong; Shen Fei; Wei Yan-Yu; Huang Min-Zhi; Tang Tao; Gong Yu-Bin

    2012-01-01

    The re-entrant double-staggered ladder slow-wave structure is employed in a high-power V-band coupled-cavity traveling-wave tube.This structure has a wide bandwidth,a moderate interaction impedance,and excellent thermal dissipation properties,as well as easy fabrication.A well-matched waveguide coupler is proposed for the structure.Combining the design of attenuators,a full-scale three-dimensional circuit model for the V-band coupled-cavity travelingwave tube is constructed.The electromagnetic characteristics and the beam-wave interaction of this structure are investigated.The beam current is set to be 100 mA,and the cathode voltage is tuned from 16.8 kV to 15.8 kV.The calculation results show that this tube can produce a saturated average output power over 100 W with an instantaneous bandwidth greater than 1.25 GHz in the frequency ranging from 58 GHz to 62 GHz.The corresponding gain and electronic efficiency can reach over 32 dB and 6.5%,respectively.

  12. Optimal design and motion control of biomimetic robotic fish

    YU JunZhi; WANG Long; ZHAO Wei; TAN Min

    2008-01-01

    This paper is concerned with the design, optimization, and motion control of a radio-controlled, multi-link, free-swimming biomimetic robotic fish based on an opti-mized kinematic and dynamic model of fish swimming. The performance of the robotic fish is determined by both the fish's morphological characteristics and ki-nematic parameters. By applying ichthyologic theories of propulsion, a design framework that takes into consideration both mechatronic constraints in physical realization and feasibility of control methods is presented, under which a multiple linked robotic fish that integrates both the carangiform and anguilliform swimming modes can be easily developed. Taking account of both theoretic hydrodynamic issues and practical problems in engineering realization, the optimal link-length-ratios are numerically calculated by an improved constrained cyclic variable method, which are successfully applied to a series of real robotic fishes. The rhythmic movements of swimming are driven by a central pattern generator (CPG) based on nonlinear oscillations, and up-and-down motion by regulating the rotating angle of pectoral fins. The experimental results verify that the presented scheme and method are effective in design and implementation.

  13. Biologically Inspired Behaviour Design for Autonomous Robotic Fish

    Jin-Dong Liu; Huosheng Hu

    2006-01-01

    Behaviour-based approach plays a key role for mobile robots to operate safely in unknown or dynamically changing environments. We have developed a hybrid control architecture for our autonomous robotic fish that consists of three layers: cognitive, behaviour and swim pattern. In this paper, we describe some main design issues of the behaviour layer, which is the centre of the layered control architecture of our robotic fish. Fuzzy logic control (FLC) is adopted here to design individual behaviours. Simulation and real experiments are presented to show the feasibility and the performance of the designed behaviour layer.

  14. Bioinspiration from fish for smart material design and function

    Lauder, G. V.; Madden, P. G. A.; Tangorra, J. L.; Anderson, E.; Baker, T. V.

    2011-09-01

    Fish are a potentially rich source of inspiration for the design of smart materials. Fish exemplify the use of flexible materials to generate forces during locomotion, and a hallmark of fish functional design is the use of body and fin deformation to power propulsion and maneuvering. As a result of nearly 500 million years of evolutionary experimentation, fish design has a number of interesting features of note to materials engineers. In this paper we first provide a brief general overview of some key features of the mechanical design of fish, and then focus on two key properties of fish: the bilaminar mechanical design of bony fish fin rays that allows active muscular control of curvature, and the role of body flexibility in propulsion. After describing the anatomy of bony fish fin rays, we provide new data on their mechanical properties. Three-point bending tests and measurement of force inputs to and outputs from the fin rays show that these fin rays are effective displacement transducers. Fin rays in different regions of the fin differ considerably in their material properties, and in the curvature produced by displacement of one of the two fin ray halves. The mean modulus for the proximal (basal) region of the fin rays was 1.34 GPa, but this varied from 0.24 to 3.7 GPa for different fin rays. The distal fin region was less stiff, and moduli for the different fin rays measured varied from 0.11 to 0.67 GPa. These data are similar to those for human tendons (modulus around 0.5 GPa). Analysis of propulsion using flexible foils controlled using a robotic flapping device allows investigation of the effect of altering flexural stiffness on swimming speed. Flexible foils with the leading edge moved in a heave show a distinct peak in propulsive performance, while the addition of pitch input produces a broad plateau where the swimming speed is relatively unaffected by the flexural stiffness. Our understanding of the material design of fish and the control of tissue

  15. Bioinspiration from fish for smart material design and function

    Fish are a potentially rich source of inspiration for the design of smart materials. Fish exemplify the use of flexible materials to generate forces during locomotion, and a hallmark of fish functional design is the use of body and fin deformation to power propulsion and maneuvering. As a result of nearly 500 million years of evolutionary experimentation, fish design has a number of interesting features of note to materials engineers. In this paper we first provide a brief general overview of some key features of the mechanical design of fish, and then focus on two key properties of fish: the bilaminar mechanical design of bony fish fin rays that allows active muscular control of curvature, and the role of body flexibility in propulsion. After describing the anatomy of bony fish fin rays, we provide new data on their mechanical properties. Three-point bending tests and measurement of force inputs to and outputs from the fin rays show that these fin rays are effective displacement transducers. Fin rays in different regions of the fin differ considerably in their material properties, and in the curvature produced by displacement of one of the two fin ray halves. The mean modulus for the proximal (basal) region of the fin rays was 1.34 GPa, but this varied from 0.24 to 3.7 GPa for different fin rays. The distal fin region was less stiff, and moduli for the different fin rays measured varied from 0.11 to 0.67 GPa. These data are similar to those for human tendons (modulus around 0.5 GPa). Analysis of propulsion using flexible foils controlled using a robotic flapping device allows investigation of the effect of altering flexural stiffness on swimming speed. Flexible foils with the leading edge moved in a heave show a distinct peak in propulsive performance, while the addition of pitch input produces a broad plateau where the swimming speed is relatively unaffected by the flexural stiffness. Our understanding of the material design of fish and the control of tissue

  16. Boat design deriving from ethnographic study: a transdisciplinary approach to Malaysian fishing boat design.

    Ask, Thomas Eric

    2011-01-01

    The goal of the project is to further the positivist discourse of design by ascertaining whether ethnographic analysis contributes to the design process. To this end, the project provides 1) a culturally appropriate conceptual fishing boat design and 2) an industrial design case study. This project identifies mechanistic and non-mechanistic design elements and presents the results of thematic analysis. This project develops a 40 GRT (gross register ton), Malaysian Class B fishing boat ...

  17. Six-Degree-of-Freedom Sensor Fish Design and Instrumentation

    Marshall C. Richmond

    2007-11-01

    Full Text Available Fish passing through dams may be injured or killed despite advances in turbinedesign, project operations and other fish bypass systems. The six-degree-of-freedom (6DOFSensor Fish device is an autonomous sensor package that characterizes the physical conditionsand physical stresses to which fish are exposed when they pass through complex hydraulicenvironments. It has been used to identify the locations and operations where conditions aresevere enough to injure or kill fish. During the design process, a set of governing equationsof motion for the Sensor Fish was derived and simulated to understand the design implica-tions of instrument selection and placement within the body of the device. The Sensor Fishpackage includes three rotation sensors, three acceleration sensors, a pressure sensor, and atemperature sensor with a sampling frequency of 2,000 Hz. Its housing is constructed of clearpolycarbonate plastic. It is 24.5 mm in diameter and 90 mm in length and weighs about 43 g,similar to the size and density of a yearling salmon smolt. The accuracy of the pressure sensorwas determined to be within 0.2 psi. In laboratory acceptance tests, the relative errors of boththe linear acceleration and angular velocity measurements were determined to be less than5%. An exposure is defined as a significant event when the acceleration reaches predefinedthresholds. Based on the different characteristic of acceleration and rotation velocities, theexposure event is categorized as either a collision between the Sensor Fish and a solid struc-ture or shear caused by turbulence. Since its development in 2005, the 6DOF Sensor Fish hasbeen deployed successfully at many major dams in the United States.

  18. Improved intake design for downstream migrating fish at hydropower plants

    This paper reports on hydroelectric power projects on the Columbia River which provided low-cost electricity to the Pacific Northwest. However, they are detrimental to anadromous fisheries resources. Anadromous fish are migratory. They begin their life in shallow mountain streams. After several months, they migrate to the ocean, where the fish grow to maturity before their return migration. Remarkably, most anadromous fish return to spawn in their natal streams. At dams, the upstream migration of grown salmon and steelhead is accomplished through fishways. The downstream migration of juveniles remains a serious problem. Juvenile fish follow the water flow during their sea-ward migration. When passing through a turbine, fish can be severely injured due to the sudden pressure drop, high velocity shear zones, and rotating turbine blades. Stunned fish that survive the gauntlet of the turbine are easy prey for sea gulls and squawfish in the tailrace of the powerhouse. Fish mortality per turbine passage is estimated at 15 percent. With nine hydropower projected on the main steam of the Columbia River, their combined mortality is very serious. The historical Columbia River anadromous run of about 12 million fish has declined to 2.5 million in recent years. Modern high-output hydraulic turbines are designed to be placed at a lower elevation to minimize cavitation damage to turbine blades. The modern design trend of deep intake submergence has caused parallel and unsteady vortex flow patterns in the forebay, resulting in a decrease in the guiding efficiency of the screens, such as at Bonneville Second Powerhouse and at Rocky Reach Project

  19. Design and Implementation of Paired Pectoral Fins Locomotion of Labriform Fish Applied to a Fish Robot

    Patar Ebenezer Sitorus; Yul Yunazwin Nazaruddin; Edi Leksono; Agus Budiyono

    2009-01-01

    In present, there are increasing interests in the research on mechanical and control system of underwater vehicles. These ongoing research efforts are motivated by more pervasive applications of such vehicles including seabed oil and gas explorations, scientific deep ocean surveys, military purposes, ecological and water environmental studies, and also entertainments.However, the performance of underwater vehicles with screw type propellers is not prospective in terms of its efficiency and maneuverability. The main weaknesses of this kind of propellers are the production of vortices and sudden generation of thrust forces which make the control of the position and motion difficult.On the other hand, fishes and other aquatic animals are efficient swimmers, posses high maneuverability, are able to follow trajectories, can efficiently stabilize themselves in currents and surges, create less wakes than currently used underwater vehicle,and also have a noiseless propulsion. The fish's locomotion mechanism is mainly controlled by its caudal fin and paired pectoral fins. They are classified into Body and/or Caudal Fin (BCF) and Median and/or paired Pectoral Fins (MPF). The study of highly efficient swimming mechanisms of fish can inspire a better underwater vehicles thruster design and its mechanism.There are few studies on underwater vehicles or fish robots using paired pectoral fins as thruster. The work presented in this paper represents a contribution in this area covering study, design and implementation of locomotion mechanisms of paired pectoral fins in a fish robot. The performance and viability of the biomimetic method for underwater vehicles are highlighted through in-water experiment of a robotic fish.

  20. Novel Design Solutions for Fishing Reel Mechanisms

    LOVASZ Erwin-Christian; MODLER Karl-Heinz; NEUMANN Rudolf; GRUESCU Corina Mihaela; PERJU Dan; CIUPE Valentin; MANIU Inocentiu

    2015-01-01

    Currently, there are various reels on the market regarding the type of mechanism, which achieves the winding and unwinding of the line. The designers have the purpose of obtaining a linear transmission function, by means of a simple and small-sized mechanism. However, the present solutions are not satisfactory because of large deviations from linearity of the transmission function and complexity of mechanical schema. A novel solution for the reel spool mechanism is proposed. Its kinematic schema and synthesis method are described. The kinematic schema of the chosen mechanism is based on a noncircular gear in series with a scotch-yoke mechanism. The yoke is driven by a stud fixed on the driving noncircular gear. The drawbacks of other models regarding the effects occurring at the ends of the spool are eliminated through achieving an appropriate transmission function of the spool. The linear function approximation with curved end-arches appropriately computed to ensure mathematical continuity is very good. The experimental results on the mechanism model validate the theoretical approach. The developed mechanism solution is recorded under a reel spool mechanism patent.

  1. Novel design solutions for fishing reel mechanisms

    Lovasz, Erwin-Christian; Modler, Karl-Heinz; Neumann, Rudolf; Gruescu, Corina Mihaela; Perju, Dan; Ciupe, Valentin; Maniu, Inocentiu

    2015-07-01

    Currently, there are various reels on the market regarding the type of mechanism, which achieves the winding and unwinding of the line. The designers have the purpose of obtaining a linear transmission function, by means of a simple and small-sized mechanism. However, the present solutions are not satisfactory because of large deviations from linearity of the transmission function and complexity of mechanical schema. A novel solution for the reel spool mechanism is proposed. Its kinematic schema and synthesis method are described. The kinematic schema of the chosen mechanism is based on a noncircular gear in series with a scotch-yoke mechanism. The yoke is driven by a stud fixed on the driving noncircular gear. The drawbacks of other models regarding the effects occurring at the ends of the spool are eliminated through achieving an appropriate transmission function of the spool. The linear function approximation with curved end-arches appropriately computed to ensure mathematical continuity is very good. The experimental results on the mechanism model validate the theoretical approach. The developed mechanism solution is recorded under a reel spool mechanism patent.

  2. Design and construction of Eicher penstock fish screens

    A penstock screen design, patented by George Eicher, was developed to accomodate site conditions at the Puntledge Dam. The screen removes juvenile and anadromous fish from the power flow and returns them to the river downstream of the dam. Hydraulic modelling at 1:10.96 scale was carried out to determine the optimum location and design of the screen, and a screen location 3 diameters downstream of the intakes was chosen. A standard Johnson stainless steel wedgewire screen with a uniform porosity of 58% was chosen. The screens are cleaned by rotating them about a horizontal trunnion at their midpoint. Total cost of the project was $4,750,000. Turbine mortality, which was greater than 60% of annual migration, was eliminated. Mortality through the screen and bypass facility is less than 1%. Details are presented of the design of the screens, fish bypass pipes and evaluation facility. 2 refs., 1 fig

  3. Constructing a DNA ladder Range for Lambda Phage by multiplex PCR

    Joseph, S; Gopalakrishnan, R; Sellappa, S

    2010-01-01

    Background and Objectives: DNA ladder contains DNA fragments of different length but with known size, used to determine the size of unknown DNA molecules. Different DNA ladders are available for expected DNA length. Conserved sequences were selected for design of primers to generate DNA fragments of known specific size."nMaterials and Methods: In this study, we describe a method by which DNA ladder was prepared based on multiplex PCR technique. Different lengths of DNA fragments were amplifie...

  4. Bending continuous structures with SMAs: a novel robotic fish design

    In this paper, we describe our research on bio-inspired locomotion systems using deformable structures and smart materials, concretely shape memory alloys (SMAs). These types of materials allow us to explore the possibility of building motor-less and gear-less robots. A swimming underwater fish-like robot has been developed whose movements are generated using SMAs. These actuators are suitable for bending the continuous backbone of the fish, which in turn causes a change in the curvature of the body. This type of structural arrangement is inspired by fish red muscles, which are mainly recruited during steady swimming for the bending of a flexible but nearly incompressible structure such as the fishbone. This paper reviews the design process of these bio-inspired structures, from the motivations and physiological inspiration to the mechatronics design, control and simulations, leading to actual experimental trials and results. The focus of this work is to present the mechanisms by which standard swimming patterns can be reproduced with the proposed design. Moreover, the performance of the SMA-based actuators' control in terms of actuation speed and position accuracy is also addressed.

  5. PLC梯形图转化为多操作数逻辑指令的设计与实现%Design and Realization of Transformation from PLC Ladder Diagram to Multiple Operands Logic Instruction

    邱盛成; 蔡启仲; 李克俭; 潘绍明

    2016-01-01

    Each operand in PLC logic instructions contain only an opcode.A new type of PLC logical instruction structure is designed, where its operation code can take multiple operands and its operands additional"auxiliary sign bit".It avoids in the process of execution logic instructions for multiple operands to decode several times.Researched on the data structure of this new instruction statement and the data structure of the ladder diagram,and using these two data structures to achieve the transformation algorithm of the ladder diagram into the new instruction list.Ladder diagram used in cascade order recursive scanning methods constructing binary tree structure,and postorder the tree traversal for an intermediate result instruction list,After the analysis of the logical relationship of intermediate result instruction list and combined process of operation for the same type of logical relations,the final instruction table is obtained.Through the series-parallel struc-ture of ladder diagram transformation test,the new instruction statements transformation result is correct.%针对每一个操作数有一个操作码的PLC逻辑指令,设计了一个操作码可带多个操作数,操作数附加“辅助符号位”的新型PLC逻辑指令,避免在执行逻辑指令过程中有多少个操作数需要译码多少次的状况;研究这种新指令语句的数据结构和梯形图的数据结构,应用这两种数据结构研究梯形图转化成新指令表的转化算法;对梯形图采用按梯级顺序递归扫描方法构造二叉树结构,然后对二叉树进行后序遍历得到一个中间结果指令表,对中间结果指令表经过逻辑关系的分析与同类型逻辑关系操作数的合并处理得到最终的指令表;通过对串并联结构梯形图的转换测试,其新指令语句的转化结果正确。

  6. A Review and Modern Approach to LC Ladder Synthesis

    Alexander J. Casson

    2011-01-01

    Full Text Available Ultra low power circuits require robust and reliable operation despite the unavoidable use of low currents and the weak inversion transistor operation region. For analogue domain filtering doubly terminated LC ladder based filter topologies are thus highly desirable as they have very low sensitivities to component values: non-exact component values have a minimal effect on the realised transfer function. However, not all transfer functions are suitable for implementation via a LC ladder prototype, and even when the transfer function is suitable the synthesis procedure is not trivial. The modern circuit designer can thus benefit from an updated treatment of this synthesis procedure. This paper presents a methodology for the design of doubly terminated LC ladder structures making use of the symbolic maths engines in programs such as MATLAB and MAPLE. The methodology is explained through the detailed synthesis of an example 7th order bandpass filter transfer function for use in electroencephalogram (EEG analysis.

  7. Assessments to determine the effect of current and alternate ladder operations on brood stock collection and behavior of hatchery fall Chinook Salmon at Little White Salmon National Fish Hatchery during 2004-05

    US Fish and Wildlife Service, Department of the Interior — Production of upriver bright fall Chinook salmon at Little White Salmon National Fish Hatchery was introduced as part of the John Day Dam mitigation program in the...

  8. Developing and implementing a career ladder program.

    Wall, Michelle

    2007-01-01

    A career ladder program is a formal management tool used not only by managers looking to recognize and retain employees, but also by employees seeking growth opportunities. A career ladder program involves careful development, frequent and effective communication during implementation, and activities focused on measuring program effectiveness. Career ladders are a way to increase productivity and staff versatility; improve morale, clinical quality, and staff satisfaction; reduce turnover; promote professional growth and job enrichment; and improve patient care. PMID:17696072

  9. Fish-inspired robots: design, sensing, actuation, and autonomy--a review of research.

    Raj, Aditi; Thakur, Atul

    2016-06-01

    Underwater robot designs inspired by the behavior, physiology, and anatomy of fishes can provide enhanced maneuverability, stealth, and energy efficiency. Over the last two decades, robotics researchers have developed and reported a large variety of fish-inspired robot designs. The purpose of this review is to report different types of fish-inspired robot designs based upon their intended locomotion patterns. We present a detailed comparison of various design features like sensing, actuation, autonomy, waterproofing, and morphological structure of fish-inspired robots reported in the past decade. We believe that by studying the existing robots, future designers will be able to create new designs by adopting features from the successful robots. The review also summarizes the open research issues that need to be taken up for the further advancement of the field and also for the deployment of fish-inspired robots in practice. PMID:27073001

  10. Perspective on rainbow-ladder truncation

    Eichmann, G; Cloet, I C; Krassnigg, A; Roberts, C D

    2008-01-01

    Prima facie the systematic implementation of corrections to the rainbow-ladder truncation of QCD's Dyson-Schwinger equations will uniformly reduce in magnitude those calculated mass-dimensioned results for pseudoscalar and vector meson properties that are not tightly constrained by symmetries. The aim and interpretation of studies employing rainbow-ladder truncation are reconsidered in this light.

  11. Perspective on rainbow-ladder truncation

    Prima facie the systematic implementation of corrections to the rainbow-ladder truncation of QCD's Dyson-Schwinger equations will uniformly reduce in magnitude those calculated mass-dimensioned results for pseudoscalar and vector meson properties that are not tightly constrained by symmetries. The aim and interpretation of studies employing rainbow-ladder truncation are reconsidered in this light

  12. Design complexity in termite-fishing tools of chimpanzees (Pan troglodytes)

    Sanz, Crickette; Call, Josep; Morgan, David

    2009-01-01

    Adopting the approach taken with New Caledonian crows (Corvus moneduloides), we present evidence of design complexity in one of the termite-fishing tools of chimpanzees (Pan troglodytes) in the Goualougo Triangle, Republic of Congo. Prior to termite fishing, chimpanzees applied a set of deliberate, distinguishable actions to modify herb stems to fashion a brush-tipped probe, which is different from the form of fishing tools used by chimpanzees in East and West Africa. This means that ‘brush-t...

  13. Six-degree-of-freedom Sensor Fish design - Governing equations and motion modeling

    Zeng, D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Richmond, M. C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Simmons, C. S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Carlson, T. J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2004-07-01

    The Sensor Fish device is being used at Northwest hydropower projects to better understand the conditions fish experience during passage through hydro turbines and other dam bypass alternatives. Since its initial development in 1997, the Sensor Fish has undergone numerous design changes to improve its function and extend the range of its use. The most recent Sensor Fish design, the three degree of freedom (3DOF) device, has been used successfully to characterize the environment fish experience when passing through turbines, in spill, or in engineered fish bypass facilities at dams. Pacific Northwest National Laboratory (PNNL) is in the process of redesigning the current 3DOF Sensor Fish device package to improve its field performance. Rate gyros will be added to the new six degree of freedom (6DOF) device so that it will be possible to observe the six linear and angular accelerations of the Sensor Fish as it passes the dam. Before the 6DOF Sensor Fish device can be developed and deployed, governing equations of motion must be developed in order to understand the design implications of instrument selection and placement within the body of the device. The report describes a fairly general formulation for the coordinate systems, equations of motion, force and moment relationships necessary to simulate the 6DOF movement of an underwater body.

  14. A marsupial robotic fish team: Design, motion and cooperation

    2010-01-01

    A bio-inspired marsupial robotic fish system composed of heterogeneous robotic fish is proposed in this paper. A miniature robotic fish, as the daughter robotic fish, can adapt to some narrow space, while the mother robotic fish, with a cabin to transport the daughter, possesses a powerful movement ability to improve the mobility and endurance of the team. The structures for mimicking bio-motion and the method for fishlike-motion are presented. A typical task of daughter-mother following is given to show the cooperation of the team. A motion model of free swimming is built based on the Lagrangian function, and the coupled dynamic and kinematic functions are calculated based on the relation between the generalized force and fluid force. Then, a neural network is trained through the data generated from this model to get a predictive yaw controller, which can control the orientation by a different offset of each link. The daughter robotic fish adopts a dynamic light source tracking approach to follow the mother, and a heterogeneous communication-based finite state machine is presented for task modeling. Experiments are carried out to verify the system.

  15. Stakeholder participation in research design and decisions: scientists, fishers, and mercury in saltwater fish.

    Burger, Joanna; Gochfeld, Michael; Fote, Tom

    2013-03-01

    Individuals who fish and eat self-caught fish make decisions about where to fish, the type to eat, and the quantity to eat. Federal and state agencies often issue consumption advisories for some fish with high mercury (Hg) concentrations, but seldom provide either the actual metal levels to the general public, or identify the fish that have low contaminant levels. Community participatory research is of growing importance in defining, studying, and resolving complex exposure and risk issues, and this paper is at the intersection of traditional stakeholder approaches and community-based participatory research. The objective of this paper is to describe the process whereby stakeholders (fishers), were involved in directing and refining research questions to address their particular informational needs about mercury levels in fish, potential risks, and methods to maintain health, by balancing the risks and benefits of fish consumption. A range of stakeholders, mainly individual fishers, fishing organizations, and other scientists, were involved at nearly every stage. Community participants influenced many aspects of the design and implementation of the research, in the determination of which fish species to sample, in the collection of the samples, and in the final analyses and synthesis, as well as the communication of results and implications of the research through their fishing club publications, talks and gatherings. By involving the most interested and affected communities, the data and conclusions are relevant to their needs because the fish examined were those they ate and wanted information about, and directly address concerns about the risk from consuming self-caught fish. Although mercury levels in fish presumed to be high in mercury are known, little information was available to the fishermen on mercury levels in fish that were low and thus provided little risk to their families. While community participatory research is more time-consuming and expensive

  16. Cutting and dismantling of the South West ladder of the Atucha I nuclear power plant

    The metallic ladder built in stainless steel was used originally to check the welding of the reactor pressure vessel. It was located between the thermal insulation and reactor pressure vessel. Because of a failure in the mechanism, which let the ladder runs around the vessel, it had to be removed. A special tool remotely operated was designed to make different cuts in the bottom of the structure in a very high radioactive location

  17. Fishing

    姜群山

    2002-01-01

    @@ Last Saturday my cousin (表兄) came to my home. We were very happy to see each other. We decided that the next day we went to fish. We got up very early that day. When we left home,the moon could still be seen in the sky.

  18. Phase separation in t-J ladders

    Rommer, Stefan; White, Steven R.; Scalapino, D. J.

    1999-01-01

    The phase separation boundary of isotropic t-J ladders is analyzed using density matrix renormalization group techniques. The complete boundary to phase separation as a function of J/t and doping is determined for a chain and for ladders with two, three and four legs. Six-chain ladders have been analyzed at low hole doping. We use a direct approach in which the phase separation boundary is determined by measuring the hole density in the part of the system which contains both electrons and hol...

  19. Six-Degree-of-Freedom Sensor Fish Design: Governing Equations and Motion Modeling

    Deng, Zhiqun; Richmond, Marshall C.; Simmons, Carver S.; Carlson, Thomas J.

    2004-08-19

    The Sensor Fish device is being used at Northwest hydropower projects to better understand the conditions fish experience during passage through hydroturbines and other dam bypass alternatives. Since its initial development in 1997, the Sensor Fish has undergone numerous design changes to improve its function and extend the range of its use. The most recent Sensor Fish design, the three degree of freedom (3DOF) device, has been used successfully to characterize the environment fish experience when passing through turbines, in spill, or in engineered fish bypass facilities at dams. Pacific Northwest National Laboratory (PNNL) is in the process of redesigning the current 3DOF Sensor Fish device package to improve its field performance. Rate gyros will be added to the new six degree of freedom (6DOF) device so that it will be possible to observe the six linear and angular accelerations of the Sensor Fish as it passes the dam. Before the 6DOF Sensor Fish device can be developed and deployed, governing equations of motion must be developed in order to understand the design implications of instrument selection and placement within the body of the device. In this report, we describe a fairly general formulation for the coordinate systems, equations of motion, force and moment relationships necessary to simulate the 6DOF movement of an underwater body. Some simplifications are made by considering the Sensor Fish device to be a rigid, axisymmetric body. The equations of motion are written in the body-fixed frame of reference. Transformations between the body-fixed and interial reference frames are performed using a formulation based on quaternions. Force and moment relationships specific to the Sensor Fish body are currently not available. However, examples of the trajectory simulations using the 6DOF equations are presented using existing low and high-Reynolds number force and moment correlations. Animation files for the test cases are provided in an attached CD. The next

  20. Ladder operators for the associated Laguerre functions

    Fakhri, H.; Chenaghlou, A.

    2004-07-01

    Introducing the associated Laguerre functions in terms of two non-negative integers, we obtain simultaneously and separately realization of the laddering equations with respect to each of the integers by means of two pairs of ladder operators. Besides, two different types of shape-invariance symmetries are realized. This approach leads to a derivation of shape-invariance equations of third type which are realized by two simultaneous raising and lowering operators of two parameters.

  1. Ladder operators for the associated Laguerre functions

    Fakhri, H [Institute for Studies in Theoretical Physics and Mathematics (IPM), PO Box 19395-5531, Tehran (Iran, Islamic Republic of); Chenaghlou, A [Institute for Studies in Theoretical Physics and Mathematics (IPM), PO Box 19395-5531, Tehran (Iran, Islamic Republic of)

    2004-07-30

    Introducing the associated Laguerre functions in terms of two non-negative integers, we obtain simultaneously and separately realization of the laddering equations with respect to each of the integers by means of two pairs of ladder operators. Besides, two different types of shape-invariance symmetries are realized. This approach leads to a derivation of shape-invariance equations of third type which are realized by two simultaneous raising and lowering operators of two parameters.

  2. Ladder operators for the associated Laguerre functions

    Introducing the associated Laguerre functions in terms of two non-negative integers, we obtain simultaneously and separately realization of the laddering equations with respect to each of the integers by means of two pairs of ladder operators. Besides, two different types of shape-invariance symmetries are realized. This approach leads to a derivation of shape-invariance equations of third type which are realized by two simultaneous raising and lowering operators of two parameters

  3. Design complexity in termite-fishing tools of chimpanzees (Pan troglodytes).

    Sanz, Crickette; Call, Josep; Morgan, David

    2009-06-23

    Adopting the approach taken with New Caledonian crows (Corvus moneduloides), we present evidence of design complexity in one of the termite-fishing tools of chimpanzees (Pan troglodytes) in the Goualougo Triangle, Republic of Congo. Prior to termite fishing, chimpanzees applied a set of deliberate, distinguishable actions to modify herb stems to fashion a brush-tipped probe, which is different from the form of fishing tools used by chimpanzees in East and West Africa. This means that 'brush-tipped fishing probes', unlike 'brush sticks', are not a by-product of use but a deliberate design feature absent in other chimpanzee populations. The specialized modifications to prepare the tool for termite fishing, measures taken to repair non-functional brushes and appropriate orientation of the modified end suggest that these wild chimpanzees are attentive to tool modifications. We also conducted experimental trials that showed that a brush-tipped probe is more effective in gathering insects than an unmodified fishing probe. Based on these findings, we suggest that chimpanzees in the Congo Basin have developed an improved fishing probe design. PMID:19324641

  4. Model identification and controller design of a fish-like robot

    Ariyanto, Irfan; Kang, Taesam; Chan, Wai Leung; Lee, Youngjae

    2007-04-01

    Robotic fish is an interesting and prospective subject to develop. The simplest fish swimming mode to be mimicked for fish robots is the ostraciiform mode which only requires caudal fin flapping. An almost submerged ostraciiform fish robot was constructed to study its swimming characteristics. The swimming direction can be controlled by changing the mean angle of caudal fin oscillation. Experiments were conducted to study the behavior of the fish robot and in particular, the transfer function between swimming path angular rate and mean angle of the caudal fin oscillation were identified. Error to signal ratio quantity was used to determine how well the model fits with the experimental data. This identification model was used to design a 2-degree-of-freedom PID controller that meets some specific requirements to improve the steering performance.

  5. Hood River and Pelton Ladder Evaluation Studies : Annual Report 1994.

    Olsen, Erik A.; French, Rod A.; Ritchey, Alan D.

    1995-09-01

    In 1992, the Northwest Power Planning Council approved the Hood River and Pelton ladder master plans within the framework of the Columbia River Basin Fish and Wildlife Program. The master plans define an approach for implementing a hatchery supplementation program in the Hood River subbasin. The hatchery program as defined in the master plans is called the Hood River Hatchery Production Program (HRPP). The HRPP will be phased in over several years and will be jointly implemented by the Oregon Department of Fish and Wildlife (ODFW) and the Confederated Tribes of the Warm Springs (CTWS) Reservation. In December 1991, a monitoring and evaluation program was implemented in the Hood River subbasin to collect life history and production information on stocks of anadromous salmonids returning to the Hood River subbasin. The program was implemented to provide the baseline information needed to: (1) evaluate various management options for implementing the HRPP and (2) determine any post-project impacts the HRPP has on indigenous populations of resident fish. Information collected during the 1992-94 fiscal years will also be used to prepare an environmental impact statement (EIS) evaluating the program`s impact on the human environment. To begin construction on project facilities, it was proposed that the HRPP be implemented in two phases. Phase I would include work that would fall under a {open_quotes}categorical exclusion{close_quotes} from NEPA, and Phase II would include work requiring an EIS prior to implementation. This report summarizes the life history and escapement data collected in the Hood River subbasin and the status work of implemented under Phase I of the HR Life history and escapement data will be used to: (1) test the assumptions on which harvest and escapement goals for the Hood River and Pelton ladder master plans are based and (2) develop biologically based management recommendations for implementing the HRPP.

  6. Fish schooling as a basis for wind farm design

    Whittlesey, Robert; Dabiri, John

    2009-11-01

    It is known that horizontal axis wind turbines (HAWT) suffer from reduced aerodynamic efficiency when in close proximity to neighboring turbines. In contrast, recent work has shown that closely spaced vertical axis wind turbines (VAWT) may benefit from enhanced performance, reducing the associated land use for VAWT wind farm installations. A potential flow model of VAWT interactions is developed to determine configurations that optimize the power output of the array. A geometric arrangement based on fish schooling has been shown to significantly increase the array performance as measured by an Array Power Coefficient, which compares the average performance of turbines in the array to an isolated turbine. The results suggest that significant gains may be obtained through careful arrangement of VAWTs, showing up to a two order of magnitude decrease in land use (equivalently, a two order of magnitude increase in power density) compared to HAWTs.

  7. Doped spin ladders under magnetic field

    This thesis deals with the physics of doped two-leg ladders which are a quasi one-dimensional and unconventional superconductor. We particularly focus on the properties under magnetic field. Models for strongly correlated electrons on ladders are studied using exact diagonalization and density-matrix renormalization group (DMRG). Results are also enlightened by using the bosonization technique. Taking into account a ring exchange it highlights the relation between the pairing of holes and the spin gap. Its influence on the dynamics of the magnetic fluctuations is also tackled. Afterwards, these excitations are probed by the magnetic field by coupling it to the spin degree of freedom of the electrons through Zeeman effect. We show the existence of doping-dependent magnetization plateaus and also the presence of an inhomogeneous superconducting phase (FFLO phase) associated with an exceeding of the Pauli limit. When a flux passes through the ladder, the magnetic field couples to the charge degree of freedom of the electrons via orbital effect. The diamagnetic response of the doped ladder probes the commensurate phases of the t-J model at low J/t. Algebraic transverse current fluctuations are also found once the field is turned on. Lastly, we report numerical evidences of a molecular superfluid phase in the 3/2-spin attractive Hubbard model: at a density low enough, bound states of four fermions, called quartets, acquire dominant superfluid fluctuations. The observed competition between the superfluid and density fluctuations is connected to the physics of doped ladders. (author)

  8. Locomotion Generation and Motion Library Design for an Anguilliform Robotic Fish

    Xuelei Niu; Jianxin Xu; Qinyuan Ren; Qingguo Wang

    2013-01-01

    In this paper,modeling,locomotion generation,motion library design and path planning for a real prototype of an Anguilliform robotic fish are presented.The robotic fish consists of four links and three joints,and the driving forces are the torques applied to the joints.Considering kinematic constraints and hydrodynamic forces,Lagrangian formulation is used to obtain the dynamic model of the fish.Using this model,three major locomotion patterns of Anguilliform fish,including forward locomotion,backward locomotion and turning locomotion are investigated.It is found that the fish exhibits different locomotion pattems by giving different reference joint angles,such as adding reversed phase difference,or adding deflections to the original reference angles.The results are validated by both simulations and experiments.Furthermore,the relations among the speed of the fish,angular frequency,undulation amplitude,phase difference,as well as the relationship between the turning radius and deflection angle are investigated.These relations provide an elaborated motion library that can be used for motion planning of the robotic fish.

  9. Design and Implementation of SoftPLC Ladder Diagram Programming Tool Based on MiniGUI%基于MiniGUI的梯形图编程工具的设计与实现

    姚家庆; 陶耀东; 郑一麟

    2013-01-01

    针对数控系统可编程逻辑控制器(PLC),使用MiniGUI实现一个梯形图编程工具.首先指出MiniGUI占用资源低、移植性好等优点.随后提出图元的数据结构、手动绘制图元的方法,在此基础之上给出梯形图的数据结构以及如何刷新梯形图.此外,编程系统使用“正向深度扫描算法”来实现梯图向IL程序的转换并且在转换之前还对梯图进行一些语法正确性的检查.最后给出一个梯形图转换的实例,验证了编辑工具的实用性.%In view of the Programmable Logic Controller ( PLC ) in numerical controller system, MiniGUI is used to realize a ladder diagram programming tool. Firstly, some advantages such as low occupancy of system resources, good portability are pointed out. Then the data structure and the method of drawing graphical objects are devised. On the the basis of graphical object, the data structure and the method of refreshing ladder diagram are proposed. In addition, an algorithm named " straight and deep traversal algorithm" is used to convert ladder diagram into IL program and syntactic correctness check is also needed befor the conversion. Finally, this paper gives a ladder diagram conversion instance which validates the utility of this tool.

  10. Evolutionary multiobjective design of a flexible caudal fin for robotic fish.

    Clark, Anthony J; Tan, Xiaobo; McKinley, Philip K

    2015-12-01

    Robotic fish accomplish swimming by deforming their bodies or other fin-like appendages. As an emerging class of embedded computing system, robotic fish are anticipated to play an important role in environmental monitoring, inspection of underwater structures, tracking of hazardous wastes and oil spills, and the study of live fish behaviors. While integration of flexible materials (into the fins and/or body) holds the promise of improved swimming performance (in terms of both speed and maneuverability) for these robots, such components also introduce significant design challenges due to the complex material mechanics and hydrodynamic interactions. The problem is further exacerbated by the need for the robots to meet multiple objectives (e.g., both speed and energy efficiency). In this paper, we propose an evolutionary multiobjective optimization approach to the design and control of a robotic fish with a flexible caudal fin. Specifically, we use the NSGA-II algorithm to investigate morphological and control parameter values that optimize swimming speed and power usage. Several evolved fin designs are validated experimentally with a small robotic fish, where fins of different stiffness values and sizes are printed with a multi-material 3D printer. Experimental results confirm the effectiveness of the proposed design approach in balancing the two competing objectives. PMID:26601975

  11. Mechanical design, fabrication, and test of biomimetic fish robot using LIPCA as artificial muscle

    Wiguna, T.; Syaifuddin, M.; Park, Hoon C.; Heo, S.

    2006-03-01

    This paper presents a mechanical design, fabrication and test of biomimetic fish robot using the Lightweight Piezocomposite Curved Actuator (LIPCA). We have designed a mechanism for converting actuation of the LIPCA into caudal fin movement. This linkage mechanism consists of rack-pinion system and four-bar linkage. We also have tested four types of caudal fin in order to examine effect of different shape of caudal fin on thrust generation by tail beat. Subsequently, based on the caudal fin test, four caudal fins which resemble fish caudal fin shapes of ostraciiform, subcarangiform, carangiform and thunniform, respectively, are attached to the posterior part of the robotic fish. The swimming test using 300 V pp input with 1 Hz to 1.5 Hz frequency was conducted to investigate effect of changing tail beat frequency and shape of caudal fin on the swimming speed of the robotic fish. The maximum swimming speed was reached when the device was operated at its natural swimming frequency. At the natural swimming frequency 1 Hz, maximum swimming speeds of 1.632 cm/s, 1.776 cm/s, 1.612 cm/s and 1.51 cm/s were reached for ostraciiform-, subcarangiform-, carangiform- and thunniform-like caudal fins, respectively. Strouhal numbers, which are a measure of thrust efficiency, were calculated in order to examine thrust performance of the present biomimetic fish robot. We also approximated the net forward force of the robotic fish using momentum conservation principle.

  12. Pair correlations in doped Hubbard ladders

    Dolfi, Michele; Bauer, Bela; Keller, Sebastian; Troyer, Matthias

    2015-11-01

    Hubbard ladders are an important stepping stone to the physics of the two-dimensional Hubbard model. While many of their properties are accessible to numerical and analytical techniques, the question of whether weakly hole-doped Hubbard ladders are dominated by superconducting or charge-density-wave correlations has so far eluded a definitive answer. In particular, previous numerical simulations of Hubbard ladders have seen a much faster decay of superconducting correlations than expected based on analytical arguments. We revisit this question using a state-of-the-art implementation of the density matrix renormalization group algorithm that allows us to simulate larger system sizes with higher accuracy than before. Performing careful extrapolations of the results, we obtain improved estimates for the Luttinger liquid parameter and the correlation functions at long distances. Our results confirm that, as suggested by analytical considerations, superconducting correlations become dominant in the limit of very small doping.

  13. Constructing a DNA ladder Range for Lambda Phage by multiplex PCR

    S Joseph

    2010-12-01

    Full Text Available Background and Objectives: DNA ladder contains DNA fragments of different length but with known size, used to determine the size of unknown DNA molecules. Different DNA ladders are available for expected DNA length. Conserved sequences were selected for design of primers to generate DNA fragments of known specific size."nMaterials and Methods: In this study, we describe a method by which DNA ladder was prepared based on multiplex PCR technique. Different lengths of DNA fragments were amplified using the primers designed according to the 1216-2136 sequence extent of lambda phage DNA. Target DNA fragments were amplified using multiplex PCR and extracted."nResults: The results showed an amplified lambda phage DNA at particular target sites by using 1 forward and 6 different reverse primers (for 100, 200, 400, 600, 800, 1000bp for the successful amplification."nConclusion: This method would be more cost effective than commercial DNA molecular weight markers.

  14. Three-dimensional array diffraction-limited foci from Greek ladders to generalized Fibonacci sequences.

    Zhang, Junyong

    2015-11-16

    Greek ladder is a technique for approximating Cn by rational numbers where n is a positive integer and C is a positive real number. For the classical Greek ladder, the value isC. Based on the continued fraction theory and algebraic equation, the classical Greek ladder in a special case can be reduced to the generalized Fibonacci sequence. By means of proper switching and binary, ternary or quaternary phase modulation, here we have successfully designed the various kinds of nano-photonic devices to produce three-dimensional array foci whose focusing properties satisfy the above mathematical characteristics. With this technology, the diffraction-limited array foci are freely designed or distributed under the requirement at the desired multiple focal planes. PMID:26698510

  15. Methodology: simplified preparation of a DNA ladder using PCR.

    Wang, T-Y; Wang, L; Wang, F

    2011-01-01

    Serving as a DNA molecular weight standard, the DNA ladder has been widely used in molecular biology applications. We developed a simple method for the preparation of a DNA marker, which involves designing primers to amplify 100- to 1000-bp DNA fragments using lambda DNA as a template for polymerase chain reaction, followed by extraction with phenol/chloroform, precipitation with ethanol and mixing. Fragments of 100- to 1000-bp DNA were successfully amplified; the sequences showed 100% identity with lambda DNA. This prepared DNA marker displayed clear bands, indicating that it can be used for molecular studies. PMID:21863555

  16. 46 CFR 72.05-20 - Stairways, ladders, and elevators.

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Stairways, ladders, and elevators. 72.05-20 Section 72... CONSTRUCTION AND ARRANGEMENT Structural Fire Protection § 72.05-20 Stairways, ladders, and elevators. (a)(1..., ladders, and elevators within main machinery spaces or cargo holds are not covered by the...

  17. 46 CFR 116.438 - Stairtowers, stairways, ladders, and elevators.

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Stairtowers, stairways, ladders, and elevators. 116.438... AND ARRANGEMENT Fire Protection § 116.438 Stairtowers, stairways, ladders, and elevators. (a) A vessel... the requirements for stairways, ladders, and elevators in § 72.05-20 of this chapter. (b)...

  18. Salmon jumping: behavior, kinematics and optimal conditions, with possible implications for fish passageway design

    Lauritzen, D V; Jordan, L K; Gordon, M S [Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA 90095-1606 (United States); Hertel, F S, E-mail: dlauritz@ccsf.ed, E-mail: fritz.hertel@csun.ed, E-mail: msgordon@ucla.ed, E-mail: ljordan@ucla.ed [Department of Biology, California State University-Northridge, Northridge, CA 91330 (United States)

    2010-09-15

    Behavioral and kinematic properties and capacities of wild migratory salmonid fishes swimming upstream and jumping up waterfalls generally have played only minor roles in the design and construction of passageways intended to help these fishes get past dams and other human-made obstacles blocking their movements. This paper reports the results of an experimental study of relevant behavioral and kinematic properties of adult kokanee salmon (Oncorhynchus nerka) jumping up waterfalls as they migrate upstream. We used a portable, adjustable apparatus to study in the field fish responding to artificial waterfalls under a range of flow conditions. We observed fish under conditions of varying water flow rates, pool depths, fall heights and fall angles. We analyzed digital video recordings of their behaviors. Kokanee salmon spontaneously jump up waterfalls within a relatively narrow range of conditions, including low flow speeds, near vertical angles and pool depth to fall height ratios near 1.0. Preferred values for each parameter are, to some extent, dependent on other parameters. In contrast to previous misconceptions, jumping behavior is initiated by running S-start accelerations from beneath the boils formed in the plunge pools below waterfalls, as opposed to C-start standing jumps from the surface. S-starts are immediately followed by burst swimming to the point of takeoff at the surface. These results can contribute to an improved basis for developing designs of fish passageways that may ultimately make them more effective and efficient.

  19. Salmon jumping: behavior, kinematics and optimal conditions, with possible implications for fish passageway design

    Behavioral and kinematic properties and capacities of wild migratory salmonid fishes swimming upstream and jumping up waterfalls generally have played only minor roles in the design and construction of passageways intended to help these fishes get past dams and other human-made obstacles blocking their movements. This paper reports the results of an experimental study of relevant behavioral and kinematic properties of adult kokanee salmon (Oncorhynchus nerka) jumping up waterfalls as they migrate upstream. We used a portable, adjustable apparatus to study in the field fish responding to artificial waterfalls under a range of flow conditions. We observed fish under conditions of varying water flow rates, pool depths, fall heights and fall angles. We analyzed digital video recordings of their behaviors. Kokanee salmon spontaneously jump up waterfalls within a relatively narrow range of conditions, including low flow speeds, near vertical angles and pool depth to fall height ratios near 1.0. Preferred values for each parameter are, to some extent, dependent on other parameters. In contrast to previous misconceptions, jumping behavior is initiated by running S-start accelerations from beneath the boils formed in the plunge pools below waterfalls, as opposed to C-start standing jumps from the surface. S-starts are immediately followed by burst swimming to the point of takeoff at the surface. These results can contribute to an improved basis for developing designs of fish passageways that may ultimately make them more effective and efficient.

  20. Design, Implementation and Control of a Fish Robot with Undulating Fins

    Mohsen Siahmansouri

    2011-11-01

    Full Text Available Biomimetic robots can potentially perform better than conventional robots in underwater vehicle designing. This paper describes the design of the propulsion system and depth control of a robotic fish. In this study, inspired by knife fish, we have designed and implemented an undulating fin to produce propulsive force. This undulating fin is a segmental anal fin that produces sinusoidal wave to propel the robot. The relationship between the individual fin segment and phase angles with the overall fin trajectory has also been discussed. This propulsive force can be adjusted and directed for fish robot manoeuvre by a mechanical system with two servomotors. These servomotors regulate the direction and depth of swimming. A wireless remote control system is designed to adjust the servomotors which enables us to control revolution, speed and phase differences of neighbor servomotors of fins. Finally, Field trials are conducted in an outdoor pool to demonstrate the relationship between robotic fish speed and fin parameters like phase difference, the number of phase and undulatory amplitude.

  1. Design and Management Criteria for Fish, Amphibian, and Reptile Communities Within Created Agricultural Wetlands

    Design and management criteria for created agricultural wetlands in the midwestern United States typically focus on maximizing the ability to process agricultural runoff. Ecological benefits for fish, amphibian, and reptiles are often secondary considerations. One example of this water quality focu...

  2. 29 CFR 1910.27 - Fixed ladders.

    2010-07-01

    ...) Hatch cover. Counterweighted hatch covers shall open a minimum of 60 degrees from the horizontal. The... angle of 60 degrees from the horizontal as indicated in figure D-5. The relationship of a fixed ladder.... Smooth-walled wells shall be a minimum of 27 inches from the centerline of rungs to the well wall on...

  3. 29 CFR 1917.119 - Portable ladders.

    2010-07-01

    ... Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... portable ladders obtained before October 3, 1983, shall be capable of supporting a 200-pound (890 N) load... center; (2) Are capable of supporting a 250-pound (1,112 N) load without deformation; and (3) Have...

  4. 29 CFR 1926.1053 - Ladders.

    2010-07-01

    ... location where they can be displaced by workplace activities or traffic, such as in passageways, doorways... identifies them as defective, or be tagged with “Do Not Use” or similar language, and shall be withdrawn from... ladder is either: (i) Immediately tagged with “Do Not Use” or similar language, (ii) Marked in a...

  5. Design and testing of fish drier system utilizing geothermal energy resource in Ie Suum, Aceh Besar

    Mubarak, Amir Zaki; Maulana, M. Ilham; Syuhada, Ahmad

    2016-03-01

    In an effort to increase the value of fish produced by the community in Krueng Raya Sub-district, it has been designed and tested a fish drier system utilizing geothermal energy resource in IeSuum Village, Krueng Raya Sub-district, Aceh Besar District. The geothermal energy is in the form of hot water with the temperature range is between 86 and 86.4 °C. Based on the design consideration, it is used a terraced rack type drier system. The drier system consists of a heat exchanger, drying chamber, and a blower to blow the air. Hot water from the geothermal source is passed into the heat exchanger to increase the air temperature outside it. The air is then blown into the drying chamber. Based on the design analysis is obtained that to dry 200 kg of fish in 24 hour, it is required a drying chamber with 1m long, 1 m width and 0.4 m high, the temperature of hot water entering the exchanger is 80 °C and the temperature of the air entering the drying chamber is maintained at 60°C. The average time required to dry fish till 10% of water level is 18-20 jam. The research is then continued by developing and testing the drying system with three layer rack to put in the fish. From the experimental result is obtained that the average water temperature flows out of the chamber is in the range of 76-78 °C and the temperature in the chamber is in the range of 57-62 °C. In addition, the weight of the fish, which initially is 20 kg, becomes12 kg in average after 18 hours drying process.

  6. LADDER SUPERSTRUCTURE-DIRECTED SYNTHESIS OF A WELL-DEFINED m-PHENELENEDIIMINO-BRIDGED LADDER POLYMETHYLSILOXANE

    Yin-sheng Lv; Zhong-jie Ren; You-zhi Wan; Ping Xie; Rong-ben Zhang

    2009-01-01

    A well-defined m-phenylenediimino-bridged ladder polymethylsiloxane (LP) was first synthesized through a well-defined ladder superstructure (LS) acting as synthetic template, which was self-assembled by concerted interaction of hydrogen bonding and aromatic π-π stacking of the monomer (M), N,N'-bis(phenyldichlorosilyl)-m-phenylenediamine. Some key characterization data of LP and, in particular, the extremely vulnerable LS with very unstable Si--Cl and Si-N groups were given. The molecular weights (Mn) of LS and LP are 5010 and 10480, corresponding to about 15 and 46 monomer units, respectively. To monitor the real in situ status of LS in solution the XRD measurements of special freeze-drying samples were performed, demonstrating two characteristic peaks of ladder structure. Most importantly, both LP and LS display exceedingly sharp resonance absorption peaks with a half peak width (△1/2) as small as < 0.3 of MeSi(NH)O2/2 moieties in 29Si-NMR spectra. It is well-known that the higher the regularity of the ladder polysiloxane, the narrower the resonance peak of the siloxane moiety on the ladder backbone, and the smaller the half peak width △1/2. Therefore, the very small values of △1/2 for both LS and LP confirm that both LS and LP possess well-defined ladder structures.

  7. Analysis of Environmental Issues Related to Small-Scale Hydroelectric Development II: Design Consideration for Passing Fish Upstream Around Dams

    Hildebrandt, S. G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bell, M. C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Anderson, J. J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Richey, E. P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Parkhurst, Z. E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    1980-08-01

    The purpose of this report is to provide general information for use by potential developers of small scale hydroelectric projects that will include facilities to pass migrating fish upstream around dams. The document is not intended to be a textbook on design of fish passage facilities, but rather to be a general guide to some factors that are important when designing such facilities.

  8. Development of Single- and Double-sided Ladders for the ILD Vertex Detectors

    Baudot, Jerome; Chon-Sen, Nathalie; Dulinski, Wojciech; Hegner, Franziska; Gelin-Galibel, Marie; Gauld, Rhorry; Goffe, Mathieu; Goldstein, Joel; Gregor, Ingrid; Hu-Guo, Christine; Koetz, Ulrich; Nomerotski, Andrei; Winter, Marc

    2012-01-01

    We discuss two projects exploring the integration of thin CMOS pixel sensors in order to prototype ladders matching the geometry needed for the ILD vertex detector. The PLUME project has designed and fabricated full-size and fully functional double- sided layers which currently reach 0.6 % X0 and aim for 0.3 % X0 in mid-2012. Another approach, SERNWIETE, consists in wrapping the sensors in a polyimide-based micro-cable to obtain a supportless single-sided ladder with a material budget around 0.15 % X0. First promising samples have been produced and the full-size prototype is expected in spring 2012.

  9. Simulation of TunneLadder Traveling-Wave Tube Input/Output Coupler Characteristics Using MAFIA

    Kory, Carol L.; Qureshi, A. Haq

    1996-01-01

    RF input/output coupler characteristics for the TunneLadder traveling-wave tube have been calculated using the three-dimensional computer code, MAFIA and compared to experimental data with good agreement. Theory behind coupling of the TunneLadder interaction circuit to input and output waveguides is presented and VSWR data is calculated for variations on principal coupler dimensions to provide insight into manufacturing tolerances necessary for acceptable performance. Accuracy of results using MAFIA demonstrates how experimental hardware testing of three-dimensional coupler designs can be reduced.

  10. Contribution of experimental fluid mechanics to the design of vertical slot fish passes

    Wang R.W.

    2010-02-01

    Full Text Available This paper presents the main results of an experimental study of mean and turbulent characteristics of flow in a scale model of a vertical slot fish pass with varying width and slope (from 5% to 15%. Experimental hydraulic modelling was combined with the study of fish behaviour in the model. The discharge coefficient, which significantly affects the design of such facilities, varied from 0.67 to 0.89 and was strongly influenced by the slope. Two distinct flow patterns were observed, depending on the slope and the fish pass width. The point of transition between the two states was determined. Low velocity areas are likely resting zones for fish and particular attention was paid to evaluating these areas. Slope was found to affect both the volume of the low velocity zone, and the value of turbulent kinetic energy in these areas. The statistical characteristics of turbulent kinetic energy in the pools were linked primarily to the maximum velocity in the jet. An analysis of the behaviour of juvenile brown trout (Salmo trutta in the scale model clearly showed that the fish avoided the areas of high velocities in the jet, except at the slot itself where they took advantage of the jet’s non-stationary character. Low-velocity areas were not frequented uniformly by fish, which stayed most frequently in the zone located just downstream from the slot and behind the small side baffle. It is suggested that future studies might investigate lower pool-length to slot-width ratios, which might make it possible to increase the slope significantly and should also examine ways of improving hydraulic conditions for fish by carefully distributing obstacles in pools.

  11. 一种阶梯型双层微带贴片天线的优化设计%Optimization design of a ladder-type double-layer microstrip patch antenna

    朱赟恩; 杨明武

    2012-01-01

    文章提出一种阶梯型双层微带贴片天线,该天线有2层贴片,第1层贴片类似阶梯状,第2层贴片呈T型;采用时域有限差分法(FDTD)工具建模仿真,优化后的天线在-12 dB的相对带宽达到了27%(2.26~2.96 GHz),完全覆盖2.4 GHz频段,其较宽的带宽满足高清数字电视传输和互联网应用的要求.%A novel ladder-type double-layer microstrip patch antenna is proposed. This antenna consists of two patches-one is ladder-typed and the other is T-shaped. The modeling and simulation is conducted by finite-difference time-domain(FDTD) method, and the results show that the relative bandwidth of the optimized antenna reaches 27% as the value of S11 is lower than -12 dB in 2. 26-2. 96 GHz frequency range, completely covering the 2. 4 GHz frequency range. And with the broad band, the requirements of high definition multimedia interface(HDMI) and Internet are met.

  12. New ladder operators for the monopole harmonics

    Fakhri, H.; Dehghani, A.; Jafari, A.

    2007-02-01

    Using the ladder operators shifting the index m of the associated Jacobi functions, for a given n, the monopole harmonics and their corresponding angular momentum operators are, respectively, extracted as the irreducible representation space and generators of su(2) Lie algebra. The indices n and m play the role of principal and azimuthal quantum numbers. By introducing the ladder operators shifting the index n of the same associated Jacobi functions, we also get a new type of the raising and lowering relations which are realized by the operators shifting only the index n of the monopole harmonics. Moreover, other symmetries, including the transformation of the irreducible representation spaces into each other, are derived based on the operators that shift the indices n and m of the monopole harmonics simultaneously and agreeably as well as simultaneously and inversely. Our results are reduced to spherical harmonics by eliminating magnetic charge of the monopole.

  13. New ladder operators for the monopole harmonics

    Using the ladder operators shifting the index m of the associated Jacobi functions, for a given n, the monopole harmonics and their corresponding angular momentum operators are, respectively, extracted as the irreducible representation space and generators of su(2) Lie algebra. The indices n and m play the role of principal and azimuthal quantum numbers. By introducing the ladder operators shifting the index n of the same associated Jacobi functions, we also get a new type of the raising and lowering relations which are realized by the operators shifting only the index n of the monopole harmonics. Moreover, other symmetries, including the transformation of the irreducible representation spaces into each other, are derived based on the operators that shift the indices n and m of the monopole harmonics simultaneously and agreeably as well as simultaneously and inversely. Our results are reduced to spherical harmonics by eliminating magnetic charge of the monopole

  14. D0 Silicon Upgrade: Ladder Assembly Sequences

    This is an abridged version of the assembly sequence described by the DO assembly subgroup of Cooper, Hrycyk, Kowalski, Rapidis, and Ratzmann. This primarily is used to indicate major steps during the sequence and to list fixturing requirements. Assembly - (1) Place support rails in (1) 3 Chip Ladder Construction fixture. The two rails get held under vacuum. (2) Apply adhesive to the region where contact will be made with the beryllium substrates. (3) Place underside beryllium pieces (active and dummy ends) into the (1) 3 Chip Ladder Construction fixture. These pieces get placed in the fixture against the appropriate pins to mimic final positioning in the bulkhead. Apply vacuum to the beryllium pieces. Allow to cure? (4) Align silicon in (1) 3 Chip Ladder Construction fixture. Reference features on the fixture will be parameterized. Holes in the fixture near the silicon center line will be targeted to set the silicon axis relative to the beryllium slot edge. Z positioning of the detectors will be achieved by shimming between the detectors and butting up the end of the silicon against the fixture. (5) Remove silicon detectors and apply adhesive to the rails and upper surfaces of the beryllium. (6) Replace silicon and check final position of the detectors. (7) Release vacuum on the rails so they cure in a stress-free state. Allow adhesive to cure. (8) Apply adhesive and align HDI to the silicon using (2) 3 Chip HDI Gluing fixture. The HDI will have tabs which are held by the fixture for location relative to the detectors. Allow adhesive to cure. (9) Move ladder to (3) 3 Chip Wirebonding Fixture. Transfer fixture to the wirebonder and bond chip-silicon and silicon-silicon.

  15. Laddering in Initial Public Offering Allocations

    Fjesme, Sturla Lyngnes

    2011-01-01

    Tying Initial Public Offering (IPO) allocations of common stock to after-listing purchases in the IPO shares, a process referred to as IPO laddering, has resulted in large-scale investigations of the major investment banks by the SEC and the National Association of Securities Dealers (NASD). This process is claimed to drive after-listing share prices above their fundamental values, and is illegal un- der the laws against market manipulation and fraud. As a result, investment ...

  16. Impurity Effect on Spin Ladder System

    Motome, Yukitoshi; Katoh, Nobuyuki; Furukawa, Nobuo; Imada, Masatoshi

    1996-01-01

    Effects of nonmagnetic impurity doping in a spin ladder system with a spin gap are investigated by the exact diagonalization as well as by the variational Monte Carlo calculations. Substantial changes in macroscopic properties such as enhancements in spin correlations and magnetic susceptibilities are observed in the low impurity concentration region, which are caused by the increase of low-energy states. These results suggest that small but finite amount of nonmagnetic impurity doping releva...

  17. A ladder Ising spin configuration. Heat capacity

    We consider a ladder Ising spin model, characterized by two couplings (interchain and intrachain couplings), to study its thermal behaviour and particularly the variation of the specific heat versus the temperature, the ratio of interaction constants and the magnetic field. It is interesting that when the competition between interchain and intrachain interactions is strong the specific heat exhibits a double peak and when the competition is not so strong the specific heat has a single peak. The spin -1/2 ladder or the system of two coupled spin chains may be realized in nature by vanadyl pyrophosphate ((VO)2P2O7) or similar materials. All these intermediate systems are today important to gain further insight into the physics of one-dimensional spin chains and the two- dimensional high - Tc spin systems, both of which have shown interesting and unusual magnetic and superconducting properties. It is plausible that experimental and theoretical studies of ladders may lead to other interesting physical phenomena. (author). 22 refs, 4 figs

  18. Braess like Paradox on Ladder Network

    Toyota, Norihito

    2015-01-01

    Braess \\cite{1} has been studied about a traffic flow on a diamond type network and found that introducing new edges to the networks always does not achieve the efficiency. Some researchers studied the Braess' paradox in similar type networks by introducing various types of cost functions. But whether such paradox occurs or not is not scarcely studied in complex networks except for Dorogovtsev-Mendes network\\cite{2}. In this article, we study the paradox on Ladder type networks, as the first step to the research about Braess' paradox on Watts and Strogatz type small world network\\cite{Watt1}\\cite{Watt2}. %We theoretically and numerically studied Braess' paradox on Ladder networks. For the purpose, we construct $4 \\times 3$ models as extensions of the original Braess' models. We analyze theoretically and numerically studied the models on Ladder networks. Last we give a phase diagram for (a) model, where the cost functions of bypasses are constant =0 or flow, base on two parameters $r$ and $p$ by numerical simu...

  19. Hood River and Pelton Ladder Evaluation Studies, Annual Report 2000-2001.

    Olsen, Erik

    2009-09-01

    The Bonneville Power Administration (BPA) funded the development of two master plans which outline the rationale, and general approach, for implementing a defined group of projects that are an integral part of a comprehensive watershed goal to 'Protect, enhance and restore wild and natural populations of anadromous and resident fish within the Hood River Subbasin'. The Hood River Production Master Plan and the Pelton Ladder Master Plan were completed in 1991 and subsequently approved by the Northwest Power Planning Council in 1992. Action items identified in the two master plans, as well as in a later document entitled 'Hood River/Pelton Ladder Master Agreement' (ODFW and CTWSRO Undated), are designed to achieve two biological fish objectives: (1) to increase production of wild summer and winter steelhead (Oncorhynchus mykiss) to levels commensurate with the subbasins current carrying capacity and (2) re-establishing a self-sustaining population of spring chinook salmon (Oncorhynchus tshawytscha). Numerical fish objectives for subbasin escapement, spawner escapement, and subbasin harvest are defined for each of these species in Coccoli (2000). Several projects are presently funded by the BPA to achieve the Hood River subbasin's numerical fish objectives for summer and winter steelhead and spring chinook salmon. They include BPA project numbers 1998-021-00 (Hood River Fish Habitat), 1998-053-03 (Hood River Production Program - CTWSRO: M&E), 1998-053-07 (Parkdale Fish Facility), 1998-053-08 (Powerdale/Oak Springs O&M), and 1998-053-12 (Hood River Steelhead Genetics Study). Collectively, they are implemented under the umbrella of what has come to be defined as the Hood River Production Program (HRPP). The HRPP is jointly implemented by the Oregon Department of Fish and Wildlife (ODFW) and The Confederated Tribes of the Warm Springs Reservation of Oregon (CTWSRO). Strategies for achieving the HRPP's biological fish objectives for the Hood

  20. SYNTHESIS AND CHARACTERIZATION OF AN ORDERED LADDER POLYESTER

    Ping-ping Zhang; Tao-yi Zhang; Chuan-feng Zhu; Yu-xia Diao; You-zhi Wan; Ping Xie; Rong-ben Zhang

    2006-01-01

    An ordered ladder polyester (LPE) was first synthesized through the ladder superstructure (LS) constructed by concerted interactions of hydroxyl- and aramide-based H-bonding and p-terphenyl (TP)-based π-stacking by dehydrochlorination condensation using phosgene (COCl2) as coupling agent. LPE was characterized by GPC, FTIR, NMR,XRD, DSC and AFM. Among them, a distinct image of regularly linear alignment corresponding to the ladder main chain of LPE was first revealed by high-resolution AFM.

  1. Artisanal fishing net float loss and a proposal for a float design solution

    Paulo de Tarso Chaves

    2016-03-01

    Full Text Available Abstract Plastic floats from fishing nets are commonly found washed up on beaches in southern Brazil. They are usually broken and show signs of having been repaired. Characteristics of floats and interviews with fishermen suggest two main causes of float loss. First, collisions between active gear, bottom trawl nets for shrimp, and passive gear, drift nets for fish, destroy nets and release fragments of them, including floats. Second, the difficulty with which floats are inserted on the float rope of the nets when they are used near the surface. Floats are inserted to replace damaged or lost floats, or they may be removed if it is desired that the nets be used in deeper waters. Floats may thus be poorly fixed to the cables and lost. Here a new float design that offers greater safety in use and for the replacement of floats is described and tested.

  2. Healthcare organization-education partnerships and career ladder programs for health care workers.

    Dill, Janette S; Chuang, Emmeline; Morgan, Jennifer C

    2014-12-01

    Increasing concerns about quality of care and workforce shortages have motivated health care organizations and educational institutions to partner to create career ladders for frontline health care workers. Career ladders reward workers for gains in skills and knowledge and may reduce the costs associated with turnover, improve patient care, and/or address projected shortages of certain nursing and allied health professions. This study examines partnerships between health care and educational organizations in the United States during the design and implementation of career ladder training programs for low-skill workers in health care settings, referred to as frontline health care workers. Mixed methods data from 291 frontline health care workers and 347 key informants (e.g., administrators, instructors, managers) collected between 2007 and 2010 were analyzed using both regression and fuzzy-set qualitative comparative analysis (QCA). Results suggest that different combinations of partner characteristics, including having an education leader, employer leader, frontline management support, partnership history, community need, and educational policies, were necessary for high worker career self-efficacy and program satisfaction. Whether a worker received a wage increase, however, was primarily dependent on leadership within the health care organization, including having an employer leader and employer implementation policies. Findings suggest that strong partnerships between health care and educational organizations can contribute to the successful implementation of career ladder programs, but workers' ability to earn monetary rewards for program participation depends on the strength of leadership support within the health care organization. PMID:25441318

  3. Larval dispersal and movement patterns of coral reef fishes, and implications for marine reserve network design.

    Green, Alison L; Maypa, Aileen P; Almany, Glenn R; Rhodes, Kevin L; Weeks, Rebecca; Abesamis, Rene A; Gleason, Mary G; Mumby, Peter J; White, Alan T

    2015-11-01

    Well-designed and effectively managed networks of marine reserves can be effective tools for both fisheries management and biodiversity conservation. Connectivity, the demographic linking of local populations through the dispersal of individuals as larvae, juveniles or adults, is a key ecological factor to consider in marine reserve design, since it has important implications for the persistence of metapopulations and their recovery from disturbance. For marine reserves to protect biodiversity and enhance populations of species in fished areas, they must be able to sustain focal species (particularly fishery species) within their boundaries, and be spaced such that they can function as mutually replenishing networks whilst providing recruitment subsidies to fished areas. Thus the configuration (size, spacing and location) of individual reserves within a network should be informed by larval dispersal and movement patterns of the species for which protection is required. In the past, empirical data regarding larval dispersal and movement patterns of adults and juveniles of many tropical marine species have been unavailable or inaccessible to practitioners responsible for marine reserve design. Recent empirical studies using new technologies have also provided fresh insights into movement patterns of many species and redefined our understanding of connectivity among populations through larval dispersal. Our review of movement patterns of 34 families (210 species) of coral reef fishes demonstrates that movement patterns (home ranges, ontogenetic shifts and spawning migrations) vary among and within species, and are influenced by a range of factors (e.g. size, sex, behaviour, density, habitat characteristics, season, tide and time of day). Some species move sharks and tuna). Larval dispersal distances tend to be habitats that are critical to the life history of focal species (e.g. home ranges, nursery grounds, migration corridors and spawning aggregations), and be

  4. Spanish unemployment persistence and the ladder effect

    Collard, Fabrice; Fonseca, Raquel; Munoz, Rafael

    2002-01-01

    This paper aims to examine unemployment persistence in Spain by the soûcalled ''ladder'' effect. This arises when highly-skilled workers who do not find a job matching their skills accept jobs which previously were occupied by less qualified staff. We develop a dynamic general equilibrium model, in which two types of workers ù characterised by their level of formal education ù coexist on the labour market. Highly educated workers are then assumed to compete with lowûskilled workers, generatin...

  5. Design and control of an embedded vision guided robotic fish with multiple control surfaces.

    Yu, Junzhi; Wang, Kai; Tan, Min; Zhang, Jianwei

    2014-01-01

    This paper focuses on the development and control issues of a self-propelled robotic fish with multiple artificial control surfaces and an embedded vision system. By virtue of the hybrid propulsion capability in the body plus the caudal fin and the complementary maneuverability in accessory fins, a synthesized propulsion scheme including a caudal fin, a pair of pectoral fins, and a pelvic fin is proposed. To achieve flexible yet stable motions in aquatic environments, a central pattern generator- (CPG-) based control method is employed. Meanwhile, a monocular underwater vision serves as sensory feedback that modifies the control parameters. The integration of the CPG-based motion control and the visual processing in an embedded microcontroller allows the robotic fish to navigate online. Aquatic tests demonstrate the efficacy of the proposed mechatronic design and swimming control methods. Particularly, a pelvic fin actuated sideward swimming gait was first implemented. It is also found that the speeds and maneuverability of the robotic fish with coordinated control surfaces were largely superior to that of the swimming robot propelled by a single control surface. PMID:24688413

  6. Design and Control of an Embedded Vision Guided Robotic Fish with Multiple Control Surfaces

    Junzhi Yu

    2014-01-01

    Full Text Available This paper focuses on the development and control issues of a self-propelled robotic fish with multiple artificial control surfaces and an embedded vision system. By virtue of the hybrid propulsion capability in the body plus the caudal fin and the complementary maneuverability in accessory fins, a synthesized propulsion scheme including a caudal fin, a pair of pectoral fins, and a pelvic fin is proposed. To achieve flexible yet stable motions in aquatic environments, a central pattern generator- (CPG- based control method is employed. Meanwhile, a monocular underwater vision serves as sensory feedback that modifies the control parameters. The integration of the CPG-based motion control and the visual processing in an embedded microcontroller allows the robotic fish to navigate online. Aquatic tests demonstrate the efficacy of the proposed mechatronic design and swimming control methods. Particularly, a pelvic fin actuated sideward swimming gait was first implemented. It is also found that the speeds and maneuverability of the robotic fish with coordinated control surfaces were largely superior to that of the swimming robot propelled by a single control surface.

  7. 29 CFR 1926.851 - Stairs, passageways, and ladders.

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Stairs, passageways, and ladders. 1926.851 Section 1926.851..., DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Demolition § 1926.851 Stairs.... (b) All stairs, passageways, ladders and incidental equipment thereto, which are covered by...

  8. Design optimization of a vaneless ``fish-friendly'' swirl injector for small water turbines

    Airody, Ajith; Peterson, Sean D.

    2015-11-01

    Small-scale hydro-electric plants are attractive options for powering remote sites, as they draw energy from local bodies of water. However, the environmental impact on the aquatic life drawn into the water turbine is a concern. To mitigate adverse consequences on the local fauna, small-scale water turbine design efforts have focused on developing ``fish-friendly'' facilities. The components of these turbines tend to have wider passages between the blades when compared to traditional turbines, and the rotors are designed to spin at much lower angular velocities, thus allowing fish to pass through safely. Galt Green Energy has proposed a vaneless casing that provides the swirl component to the flow approaching the rotor, eliminating the need for inlet guide vanes. We numerically model the flow through the casing using ANSYS CFX to assess the evolution of the axial and circumferential velocity symmetry and uniformity in various cross-sections within and downstream of the injector. The velocity distributions, as well as the pressure loss through the injector, are functions of the pitch angle and number of revolutions of the casing. Optimization of the casing design is discussed via an objective function consisting of the velocity and pressure performance measures.

  9. Designing a mathematical model of management techniques (TQM, BPR in Zahedan , weave fishing net industries

    Dr.Baqer Kord, Dr. Habibollah Salarzehi, Hamed Aramesh, Somayeh Mousavi

    2010-10-01

    Full Text Available Currently reengineering and Total Quality Management (TQM techniques known improvement in organizations. in this research initially a Mathematical model was designed to find out the main factors in relative reengineering and TQM. Based on finding factors of Model, a 40 element questionary formed and the questionnaire distributed among the staff of fishing net factory in a random order, finding by using of SPSS, the data analyzed and concluding Remark shows the installation and acceptance of TQM by using reengineering is possible to the factory.

  10. The use of morphometric analysis to predict the swimming efficiency of two Neotropical long-distance migratory species in fish passage

    Lucileine de Assumpção; Maristela Cavicchioli Makrakis; Sergio Makrakis; Ricardo Luiz Wagner; Patrícia Sarai da Silva; Ariane Furtado de Lima; Elaine Antoniassi Luiz Kashiwaqui

    2012-01-01

    This study investigated the external body morphology (based on morphometric data) and the swimming efficiency in fish passages (based on the ascent time in a fish ladder) of two Neotropical long-distance migratory species. The fish were collected in the fish ladder of the Porto Primavera Hydroelectric Power Plant (known as Engenheiro Sergio Motta), upper Paraná River, Brazil. The species differ in several morphometric ratios related to swimming performance. Prochilodus lineatus exhibited a hi...

  11. SUSY's Ladder: reframing sequestering at Large Volume

    Reece, Matthew; Xue, Wei

    2016-04-01

    Theories with approximate no-scale structure, such as the Large Volume Scenario, have a distinctive hierarchy of multiple mass scales in between TeV gaugino masses and the Planck scale, which we call SUSY's Ladder. This is a particular realization of Split Supersymmetry in which the same small parameter suppresses gaugino masses relative to scalar soft masses, scalar soft masses relative to the gravitino mass, and the UV cutoff or string scale relative to the Planck scale. This scenario has many phenomenologically interesting properties, and can avoid dangers including the gravitino problem, flavor problems, and the moduli-induced LSP problem that plague other supersymmetric theories. We study SUSY's Ladder using a superspace formalism that makes the mysterious cancelations in previous computations manifest. This opens the possibility of a consistent effective field theory understanding of the phenomenology of these scenarios, based on power-counting in the small ratio of string to Planck scales. We also show that four-dimensional theories with approximate no-scale structure enforced by a single volume modulus arise only from two special higher-dimensional theories: five-dimensional supergravity and ten-dimensional type IIB supergravity. This gives a phenomenological argument in favor of ten dimensional ultraviolet physics which is different from standard arguments based on the consistency of superstring theory.

  12. Climbing the Ladder: Experience with Developing a Large Group Genetic Counselor Career Ladder at Children's National Health System.

    Kofman, Laura; Seprish, Mary Beth; Summar, Marshall

    2016-08-01

    Children's National Health System (CNHS) is a not-for-profit pediatric hospital that employs around twenty genetic counselors in a range of specialties, including clinical pediatric, neurology, fetal medicine, research, and laboratory. CNHS lacked a structured system of advancement for their genetic counselors; therefore, a formal career ladder was proposed by the genetic counselors based on years of experience, responsibility, and job performance. This career ladder utilized monetary, academic, and seniority incentives to encourage advancement and continue employment at CNHS. The creation and ultimate approval of the career ladder required direct input from genetic counselors, Department Chairs, and Human Resource personnel. The establishment of a genetic counselor career ladder at CNHS will hopefully benefit the profession of genetic counselors as a whole and allow other facilities to create and maintain their own career ladder to meet the needs of the growing, competitive, field of genetic counseling. PMID:27215631

  13. Magnetizing and heating quantum spin ladders

    Andrey Zheludev

    2008-11-01

    Quasi-one-dimensional quantum spin liquids, such as weakly coupled even-legged S=1/2 spin ladders or spin tubes, have a singlet non-magnetic ground state and gap in the excitation spectrum. Their low-temperature properties can be described in terms of triplet massive quasiparticles. These magnons possess some unique features due to the peculiar topology of one dimension. For example, two-particle interactions totally destroy single-particle states for certain energy and momentum transfers, resulting in the so-called termination of the magnon spectrum. At high field a Bose–Einstein condensation of these magnons produces a `quantum spin solid' phase, where `conventional` antiferromagnetic order coexists with excitations that are totally outside conventional spin wave theory. At finite temperatures strong repulsion between quasiparticles leads to a universal renormalization of their masses and lifetimes. These diverse phenomena are best probed by neutron scattering experiments that directly measure the spin correlation functions and excitation spectra.

  14. Macrocomposite mechanical design, modeling, and behavior of physical models of bioinspired fish armor

    Browning, Ashley; Ortiz, Christine; Boyce, Mary C.

    2012-02-01

    The macrocomposite design of flexible biological exoskeletons, consisting of overlapping mineralized armor units embedded in a compliant tissue, is a key determinant of their mechanical function (e.g penetration resistance and biomechanical flexibility). Here, we investigate the role of macrocomposite structure, composition, geometric orientation, and spatial distribution in a flexible model natural armor system present in the majority of teleost fish species. Physical multi-material composite models are fabricated using a combination of 3-D printing and molding methods. Mechanical experiments using digital image correlation enable measurement of both the macroscopic response and underlying deformation mechanisms during various loading scenarios. Finite element-based mechanical models yield detailed insights into the roles and the tradeoffs of the composite structure providing constraint, shear, and bending mechanisms to impart protection and flexibility.

  15. Design of Heat Pipe Type Adsorption Ice Maker for Fishing Boats

    王丽伟; 王如竹; 夏再忠; 吴静怡

    2005-01-01

    A heat pipe type adsorption ice maker with two adsorbers for fishing boats is designed by using ammonia as refrigerant and compound of activated carbon-GaG12 as adsorbent. This type of heat pipe adsorber can solve the problem of incompatibility between ammonia, copper, seawater and steel. The working process of the ice maker with 8.7kg adsorbent per bed is simulated. The results show that the optimal semi-cycle time is about 9min at the evaporating temperature of -15℃, where the corresponding cooling power, specific cooling power per kilogram adsorbent SCP and coefficient of refrigerant performance COP are respectively 3.6 kW, 217 W·kg-1 and 0.404.

  16. Notebook Positioning by Perceptual Map and Laddering Method

    Mehdi Zaribaf; Nora Shameli

    2012-01-01

    The purpose of this applied paper is to determine positioning of laptops by perceptual map and laddering method. Data collection method was survey using questionnaire. First by using the views of computer experts of selected brands, including Sony, Acer, Asus, Dell and Msi, 5 among 20 attributes, which were considered more important, were selected through application of factor analysis technique. Then, after classification of these features by laddering technique, they were analyzed by using ...

  17. Quantum phase competition in antiferromagnetic spin-1 ladders

    Motivated by recent chemical explorations into organic-radical-based higher-spin ladder systems, we study the ground-state properties of a wide class of antiferromagnetic spin-1 ladders. Numerical analysis featuring the level-spectroscopy technique reveals the rich phase diagram, correcting a preceding nonlinear-sigma-model prediction. A variational analysis well interprets the phase competition with particular emphasis on the re-entrant phase boundary on the way from single to coupled chains. (author)

  18. A review and modern approach to LC ladder synthesis

    Casson, Alexander J.; Esther Rodriguez-Villegas

    2011-01-01

    Ultra low power circuits require robust and reliable operation despite the unavoidable use of low currents and the weak inversion transistor operation region. For analogue domain filtering doubly terminated LC ladder based filter topologies are thus highly desirable as they have very low sensitivities to component values: non-exact component values have a minimal effect on the realised transfer function. However, not all transfer functions are suitable for implementation via a LC ladder proto...

  19. E3: Education, Experience, Employment The Economic Ladder to Success

    Anne L Seifert

    2011-10-01

    Science, Technology, Engineering, and Math (STEM) literate citizenry is critical for Idaho's economy to effectively compete and grow in today's global marketplace and enhance Idaho workforce capabilities. Idaho's blueprint presents a collaboration design developed by a group of Idaho stakeholders including state level (STEM) educators, state and federal government, other agencies, and industry across the state. The purpose the Idaho Learn and Earn Blueprint Design is to describe a comprehensive plan for improving STEM education in Idaho through a collaborative partnerships and a series of grant supported projects underpinning this strategic design process building pathways to overcome hurdles in today's economy, and moving communities and families up their economic ladder. The Idaho Learn and Earn Blueprint Design focuses on three industry sectors; energy, advanced manufacturing, and health care. All are important in Idaho and have room for job growth potential among both displaced workers and graduates. Representatives from each sector are members of the design team and assist in developing grants and implementing the actions outlined in the design as the program goes forward. Idaho's current programs are generally institution specific. Each of the state's two-year colleges, along with regional groups and employers, are already working towards improving STEM education across the state. A key aspect of this design is to bring these groups together to focus on four unique goals: (1) Providing industry driven curriculum directly tied to skill based career needs; (2) Enhancing collaboration among stakeholders; (3) Providing access to learn and earn programs; and (4) Improving public and student awareness and interest in targeted industry sector career and educational opportunities.

  20. Optimization of the marinating conditions of cassava fish (Pseudotolithus sp.) fillet for Lanhouin production through application of Doehlert experimental design.

    Kindossi, Janvier Mêlégnonfan; Anihouvi, Victor Bienvenu; Vieira-Dalodé, Générose; Akissoé, Noël Houédougbé; Hounhouigan, Djidjoho Joseph

    2016-03-01

    Lanhouin is a traditional fermented salted fish made from the spontaneous and uncontrolled fermentation of whole salted cassava fish (Pseudotolithus senegalensis) mainly produced in the coastal regions of West Africa. The combined effects of NaCl, citric acid concentration, and marination time on the physicochemical and microbiological characteristics of the fish fillet used for Lanhouin production were studied using a Doehlert experimental design with the objective of preserving its quality and safety. The marination time has significant effects on total viable and lactic acid bacteria counts, and NaCl content of the marinated fish fillet while the pH was significantly affected by citric acid concentration and marination duration with high regression coefficient R (2) of 0.83. The experiment showed that the best conditions for marination process of fish fillet were salt ratio 10 g/100 g, acid citric concentration 2.5 g/100 g, and marination time 6 h. These optimum marinating conditions obtained present the best quality of marinated flesh fish leading to the safety of the final fermented product. This pretreatment is necessary in Lanhouin production processes to ensure its safety quality. PMID:27004115

  1. Evaluation of swimming capability and potential velocity barrier problems for fish. Part A: Swimming performance of selected warm and cold water fish species relative to fish passage and fishway design

    The objective of this study was to provide information about the swimming capability of several widely distributed, economically or recreationally important fish species, for use in mitigating potential velocity barrier problems associated with hydroelectric power facilities. Swimming capability of anadromous and landlocked Atlantic salmon, brook trout, brown trout, lake sturgeon, and walleye, collected from various locations throughout Canada, were investigated to develop criteria for sustained, prolonged, burst swimming performance characteristics of the study species, fish physiology, life history and migration distance on swimming performance. Swimming performance characteristics in the wild, especially the use of physiological telemetry, as well as development of new methodology for the measurement of burst speed was also central to the study. Models were derived to describe swimming capabilities for each study species/life stage in relation to fish length, water velocity, water temperature, and other significant environmental factors. The data will form the basis of guideline development and decision making to improve design and evaluation of fish passage facilities. A series of annotated bibliographies resulting from the study are described in Appendix B. 74 refs., 8 tabs., figs., 2 appendices

  2. Dynamics of blood flow in a microfluidic ladder network

    Maddala, Jeevan; Zilberman-Rudenko, Jevgenia; McCarty, Owen

    The dynamics of a complex mixture of cells and proteins, such as blood, in perturbed shear flow remains ill-defined. Microfluidics is a promising technology for improving the understanding of blood flow under complex conditions of shear; as found in stent implants and in tortuous blood vessels. We model the fluid dynamics of blood flow in a microfluidic ladder network with dimensions mimicking venules. Interaction of blood cells was modeled using multiagent framework, where cells of different diameters were treated as spheres. This model served as the basis for predicting transition regions, collision pathways, re-circulation zones and residence times of cells dependent on their diameters and device architecture. Based on these insights from the model, we were able to predict the clot formation configurations at various locations in the device. These predictions were supported by the experiments using whole blood. To facilitate platelet aggregation, the devices were coated with fibrillar collagen and tissue factor. Blood was perfused through the microfluidic device for 9 min at a physiologically relevant venous shear rate of 600 s-1. Using fluorescent microscopy, we observed flow transitions near the channel intersections and at the areas of blood flow obstruction, which promoted larger thrombus formation. This study of integrating model predictions with experimental design, aids in defining the dynamics of blood flow in microvasculature and in development of novel biomedical devices.

  3. Percent Stomach Emptiness in Fish Collections: Sources of Variation and Study Design Implications

    We summarized fish stomach content data from 369,000 fish from 402 species in 1,096 collections made between 1925 and 2009 and report on the percentage of individuals with empty stomachs (PES). The mean PES among all species, locations, habitats, dates, and collection methods was...

  4. Hood River production program monitoring and evaluation. Report A: Hood River and Pelton Ladder evaluation studies. Annual report for 1996

    In 1992, the Northwest Power Planning Council approved the Hood River and Pelton Ladder master plans within the framework of the Columbia River Basin Fish and Wildlife Program. The master plans define an approach for implementing a hatchery supplementation program in the Hood River subbasin. The hatchery program, as defined in the master plans, is called the Hood River Production Program (HRPP). The HRPP will be implemented at a reduced hatchery production level until (1) the construction of all proposed hatchery facilities has been completed and (2) numbers of returning wild jack and adult fish are sufficient to meet broodstock collection goals. It is anticipated that construction on the hatchery production facilities will be completed by the spring of 1998. The HRPP is jointly implemented by the Oregon Department of Fish and Wildlife (ODFW) and the Confederated Tribes of the Warm Springs (CTWS) Reservation

  5. PT-symmetric ladders with a scattering core

    We consider a PT-symmetric chain (ladder-shaped) system governed by the discrete nonlinear Schrödinger equation where the cubic nonlinearity is carried solely by two central “rungs” of the ladder. Two branches of scattering solutions for incident plane waves are found. We systematically construct these solutions, analyze their stability, and discuss non-reciprocity of the transmission associated with them. To relate the results to finite-size wavepacket dynamics, we also perform direct simulations of the evolution of the wavepackets, which confirm that the transmission is indeed asymmetric in this nonlinear system with the mutually balanced gain and loss. - Highlights: • We model a PT-symmetric ladder system with cubic nonlinearity on two central rungs. • We examine non-reciprocity and stability of incident plane waves. • Simulations of wavepackets confirm our results

  6. Ladder polymers for use as high temperature stable resins or coatings

    Meador, Mary Ann (Inventor)

    1990-01-01

    An object of the invention is to synthesize a new class of ladder and partial ladder polymers. In accordance with the invention, the new class of ladder and partial ladder polymers are synthesized by polymerizing a bis-dienophile with a bis-diene. Another object of the invention is to provide a fabricated, electrically conducting, void free composite comprising the new class of the ladder and partial ladder polymers described above. The novelty of the invention relates to a new class of ladder and partial ladder polymers and a process for synthesizing these polymers. These polymers are soluble in common organic solvents and are characterized with a unique dehydration property at temperatures of 300 to 400 C to provide thermo-oxidatively stable pentiptycene units along the polymeric backbone. These polymers are further characterized with high softening points and good thermo-oxidative stability properties. Thus these polymers have potential as processable, matrix resins for high temperature composite applications.

  7. Analysis of environmental issues related to small scale hydroelectric development. II. Design considerations for passing fish upstream around dams. Environmental Sciences Division Publication No. 1567

    Hildebrand, S.G. (ed.)

    1980-08-01

    The possible requirement of facilities to move migrating fish upstream around dams may be a factor in determining the feasibility of retrofitting small dams for hydroelectric generation. Basic design considerations are reported that should be evaluated on a site-specific basis if upstream fish passage facilities are being considered for a small scale hydroelectric project (defined as an existing dam that can be retrofitted to generate 25 MW or less). Information on general life history and geographic distribution of fish species that may require passage is presented. Biological factors important in the design of upstream passage facilities are discussed: gas bubble disease, fish swimming speed, oxygen consumption by fish, and diel and photo behavior. Three general types of facilities (fishways, fish locks, and fish lifts) appropriate for upstream fish passage at small scale hydroelectric projects are described, and size dimensions are presented. General design criteria for these facilities (including fish swimming ability and behavior) and general location of facilities at a site are discussed. Basic cost considerations for each type of passage facility, including unit cost, operation and maintenance costs, and costs for supplying attraction water, are indicated.

  8. Stomach emptiness in fishes: Sources of variation and study design implications

    Vinson, M.R.; Angradi, T.R.

    2011-01-01

    This study summarizes fish stomach content data from 369,000 fish from 402 species in 1,096 collections and reports on the percentage of individuals with empty stomachs. The mean percentage of individuals with empty stomachs among all species, locations, habitats, seasons, regions, and collection methods was 26.4%. Mean percentage of individuals with empty stomachs varied significantly among fish collection gear types, taxonomic orders, trophic groups, feeding behaviors, and habitats, and with species length at maturity. Most of the variation in percentage of individuals with empty stomachs was explained by species length at maturity, fish collection gear type, and two autecological factors: trophic group (piscivore percentage of individuals with empty stomachs > non-piscivore percentage of individuals with empty stomachs) and feeding habitat (water column feeder percentage of individuals with empty stomachs > benthic feeder percentage of individuals with empty stomachs). After accounting for variation with fish length, the percentage of individuals with empty stomachs did not vary with the stomach removal collection method (dissection vs. gastric lavage), feeding time (diurnal or nocturnal), or time of collection (day or night). The percentage of individuals with empty stomachs was similar between fresh and saltwater fish, but differed within finer habitat classifications and appeared to follow a general prey availability or productivity gradient: percentage of individuals with empty stomachs of open ocean collections > estuary collections, lentic > lotic, and pelagic > littoral. Gear type (active or passive) was the most influential factor affecting the occurrence of empty stomachs that can be readily controlled by researchers.

  9. Notebook Positioning by Perceptual Map and Laddering Method

    Mehdi Zaribaf

    2012-01-01

    Full Text Available The purpose of this applied paper is to determine positioning of laptops by perceptual map and laddering method. Data collection method was survey using questionnaire. First by using the views of computer experts of selected brands, including Sony, Acer, Asus, Dell and Msi, 5 among 20 attributes, which were considered more important, were selected through application of factor analysis technique. Then, after classification of these features by laddering technique, they were analyzed by using another questionnaire to determine the position of each brand in the perceptual map. We try to show factors and laptop brands position with regard two factors of price and quality in the resulted perceptual map.

  10. Magnetic properties and quantum entanglement on decorated zigzag ladder

    Magnetic properties and quantum entanglement of Heisenberg model with two-, three- and four- site exchange interactions on zigzag ladder are studied. Magnetic properties and concurrence (measure of quantum entanglement) are analyzed by means of variational mean-field-like treatment based on the Gibbs-Bogoliubov inequality. The magnetization plateau and second-order phase transition were obtained. A comparison of the entanglement and magnetic behavior for zigzag ladder is made. We have found that in the antiferromagnetic region the behavior of the concurrence coincides with the magnetization one

  11. DUNDRUM Restriction-Intrusion of Liberty Ladders (DRILL) Audit Toolkit

    Kennedy, Harry G

    2011-09-01

    This series of rating \\'ladders\\' is intended to allow a quantitative and qualitative analysis of the use of restrictive and intrusive interventions as part of the therapeutic management of violence and aggression in psychiatric hospital settings. This is an evolving handbook. The ladders are currently organised to facilitate a behavioural analysis. Context, antecedents, behaviour, interventions, consequences are conceptualised as a series of events organised in temporal sequence so that causes, interactions and effects can be considered. The complexity of analysis possible is limited by the statistical power of the numbers of cases and events available. \\r\

  12. Transient Two-Dimensional Infrared Spectroscopy in a Vibrational Ladder.

    Kemlin, Vincent; Bonvalet, Adeline; Daniault, Louis; Joffre, Manuel

    2016-09-01

    We report on transient 2D Fourier transform infrared spectroscopy (2DIR) after vibrational ladder climbing induced in the CO-moiety longitudinal stretch of carboxyhemoglobin. The population distribution, spreading up to seven vibrational levels, results in a nonequilibrium 2DIR spectrum evidencing a large number of peaks that can be easily attributed to individual transitions thanks to the anharmonicity of the vibrational potential. We discuss the physical origin of the observed peaks as well as the qualitative behavior of the subsequent dynamics governed by population relaxation in the vibrational ladder. PMID:27508408

  13. Walla Walla River Fish Passage Operations Project : Annual Progress Report October 2007 - September 2008.

    Bronson, James P.; Duke, Bill; Loffink, Ken

    2008-12-30

    In the late 1990s, the Confederated Tribes of the Umatilla Indian Reservation, Oregon Department of Fish and Wildlife, and Washington Department of Fish and Wildlife, along with many other agencies, began implementing fisheries restoration activities in the Walla Walla Basin. An integral part of these efforts is to alleviate the inadequate fish migration conditions in the basin. Migration concerns are being addressed by removing diversion structures, constructing fish passage facilities, implementing minimum instream flow requirements, and providing trap and haul efforts when needed. The objective of the Walla Walla River Fish Passage Operations Project is to increase the survival of migrating adult and juvenile salmonids in the Walla Walla River basin. The project is responsible for coordinating operation and maintenance of ladders, screen sites, bypasses, trap facilities, and transportation equipment. In addition, the project provides technical input on passage and trapping facility design, operation, and criteria. Operation of the various passage facilities and passage criteria guidelines are outlined in an annual operations plan that the project develops. Beginning in March of 2007, two work elements from the Walla Walla Fish Passage Operations Project were transferred to other projects. The work element Enumeration of Adult Migration at Nursery Bridge Dam is now conducted under the Walla Walla Basin Natural Production Monitoring and Evaluation Project and the work element Provide Transportation Assistance is conducted under the Umatilla Satellite Facilities Operation and Maintenance Project. Details of these activities can be found in those project's respective annual reports.

  14. Triptycene-based ladder monomers and polymers, methods of making each, and methods of use

    Pinnau, Ingo

    2015-02-05

    Embodiments of the present disclosure provide for a triptycene-based A-B monomer, a method of making a triptycene-based A-B monomer, a triptycene-based ladder polymer, a method of making a triptycene-based ladder polymers, a method of using triptycene-based ladder polymers, a structure incorporating triptycene-based ladder polymers, a method of gas separation, and the like.

  15. Visualization, analysis, and design of COMBO-FISH probes in the grid-based GLOBE 3D genome platform.

    Kepper, Nick; Schmitt, Eberhard; Lesnussa, Michael; Weiland, Yanina; Eussen, Hubert B; Grosveld, Frank G; Hausmann, Michael; Knoch, Tobias A

    2010-01-01

    The genome architecture in cell nuclei plays an important role in modern microscopy for the monitoring of medical diagnosis and therapy since changes of function and dynamics of genes are interlinked with changing geometrical parameters. The planning of corresponding diagnostic experiments and their imaging is a complex and often interactive IT intensive challenge and thus makes high-performance grids a necessity. To detect genetic changes we recently developed a new form of fluorescence in situ hybridization (FISH) - COMBinatorial Oligonucleotide FISH (COMBO-FISH) - which labels small nucleotide sequences clustering at a desired genomic location. To achieve a unique hybridization spot other side clusters have to be excluded. Therefore, we have designed an interactive pipeline using the grid-based GLOBE 3D Genome Viewer and Platform to design and display different labelling variants of candidate probe sets. Thus, we have created a grid-based virtual "paper" tool for easy interactive calculation, analysis, management, and representation for COMBO-FISH probe design with many an advantage: Since all the calculations and analysis run in a grid, one can instantly and with great visual ease locate duplications of gene subsequences to guide the elimination of side clustering sequences during the probe design process, as well as get at least an impression of the 3D architectural embedding of the respective chromosome region, which is of major importance to estimate the hybridization probe dynamics. Beyond, even several people at different locations could work on the same process in a team wise manner. Consequently, we present how a complex interactive process can profit from grid infrastructure technology using our unique GLOBE 3D Genome Platform gateway towards a real interactive curative diagnosis planning and therapy monitoring. PMID:20543436

  16. Corrosion Control Specialist Career Ladder AFSC 53530, 53550, 53570, and 53690. Occupational Survey Report.

    Air Force Occupational Measurement Center, Lackland AFB, TX.

    The report describes the results of a detailed occupational survey of the corrosion control career ladder. Responses to a 457-task, time rating inventory from 1,015 personnel (representing 64 percent of the career field) were analyzed to produce seven specific findings and the career ladder structure. The career ladder includes a variety of jobs…

  17. The matrix Lie algebra on a one-step ladder is zero product determined

    Brice, Daniel

    2015-01-01

    The class of matrix algebras on a ladder $\\mathcal{L}$ generalizes the class of block upper triangular matrix algebras. It was previously shown that the matrix algebra on a ladder $\\mathcal{L}$ is zero product determined under matrix multiplication. In this article, we show that the matrix algebra on a one-step ladder is zero product determined under the Lie bracket.

  18. Design and demonstration of a fish robot actuated by a SMA-driven actuation system

    Le, Chan H.; Nguyen, Quang S.; Park, Hoon C.

    2010-04-01

    This paper presents a concept of a fish robot actuated by an SMA-based actuator. The bending-type actuator system is composed of a 0.1mm diameter SMA wire and a 0.5mm thick glass/epoxy strip. The SMA wire is installed to the bent composite strip. The actuator can produce about 200gf of blocking force and 3.5mm displacement at the center of the glass/epoxy strip. The bending motion of the actuator is converted into the tail-beat motion of a fish robot through a linkage system. The fish robot is evaluated by measuring the tail-beat angle, swimming speed and thrust produced by the fish robot. The tail-beat angle is about 20° and the maximum swimming speed is about 1.6cm/s. The measured thrust is about 0.4gf when the fish robot is operated at 0.9Hz.

  19. Design of object surveillance system based on enhanced fish-eye lens

    Jianhui Wu; Kuntao Yang; Qiaolian Xiang; Nanyang Zhang

    2009-01-01

    A new method is proposed for the object surveillance system based on the enhanced fish-eye lens and the high speed digital signal processor (DSP). The improved fish-eye lens images an ellipse picture on the charge-coupled device (CCD) surface, which increases both the utilization rate of the 4:3 rectangular CCD and the imaging resolution, and remains the view angle of 183°. The algorithm of auto-adapted renewal background subtraction (ARBS) is also explored to extract the object from the monitoring image. The experimental result shows that the ARBS algorithm has high anti-jamming ability and high resolution, leading to excellent object detecting ability from the enhanced elliptical fish-eye image under varies en-vironments. This system has potential applications in different security monitoring fields due to its wide monitoring space, simple structure, working stability, and reliability.

  20. Towards flavored bound states beyond rainbows and ladders

    El-Bennich, B; Paracha, M A; de Melo, J P B C

    2013-01-01

    We give a snapshot of recent progress in solving the Dyson-Schwinger equation with a beyond rainbow-ladder ansatz for the dressed quark-gluon vertex which includes ghost contributions. We discuss the motivations for this approach with regard to heavy-flavored bound states and form factors and briefly describe future steps to be taken.

  1. Breathers in Josephson junction ladders: Resonances and electromagnetic wave spectroscopy

    Miroshnichenko, A. E.; Flach, S.; Fistul, M.;

    2001-01-01

    We present a theoretical study of the resonant interaction between dynamical localized states (discrete breathers) and linear electromagnetic excitations (EE's) in Josephson junction ladders. By making use of direct numerical simulations we find that such an interaction manifests itself by resonant...

  2. Towards flavored bound states beyond rainbows and ladders

    El-Bennich, B.; Rojas, E.; Melo, J. P. B. C. de [Laboratório de Física Teórica e Computacional, Universidade Cruzeiro do Sul, São Paulo 01506-000 SP (Brazil); Paracha, M. A. [Laboratorio de Fisica Teorica e Computacional, Universidade Cruzeiro do Sul, Sao Paulo 01506-000 SP, Brazil and Centre for Advanced Mathematics and Physics, National University of Science and Technology, Islamabad (Pakistan)

    2014-11-11

    We give a snapshot of recent progress in solving the Dyson-Schwinger equation with a beyond rainbow-ladder ansatz for the dressed quark-gluon vertex which includes ghost contributions. We discuss the motivations for this approach with regard to heavy-flavored bound states and form factors and briefly describe future steps to be taken.

  3. 29 CFR 1910.25 - Portable wood ladders.

    2010-07-01

    ... library ladders are not specifically covered by this section. (b) Materials—(1) Requirements applicable to... types: Type I—Industrial stepladder, 3 to 20 feet for heavy duty, such as utilities, contractors, and industrial use. Type II—Commercial stepladder, 3 to 12 feet for medium duty, such as painters, offices,...

  4. Superconductivity and magnetic properties of spin-ladder compounds

    A review is given of the structural, magnetic and transport studies on two-leg spin-ladder (M2Cu2O3)m(CuO2)n systems (where M are divalent or/and trivalent cations). The crystals belonging to these systems consist of two interpenetrated subsystems. The first subsystem [M2Cu2O3] is composed of (Cu2O3) two-leg ladder planes and M ions coordinated to them. The second subsystem consists of CuO2 1D-chains. In these materials, the superconductivity was discovered for m/n = 1/1, 5/7, 7/10. The intrinsic and extrinsic superconducting properties of spin-ladder systems are presented and discussed in detail. The important role played by the hole transfer from CuO2 planes to the spin-ladder planes is stressed. It is shown that the superconductivity in this new family of high-temperature superconductors should be described as an extreme type II limit. (orig.)

  5. Predictors of Outcomes in a Performance Ladder Program.

    Dicks, Robert H.; McHenry, James D.

    1985-01-01

    Investigated variables from initial inmate evaluations at a state penitentiary as predictors of inmate success in behavioral ladder program. Results indicated that academic test variables were best predictors of overall success level, attitudes, and work habits. Personality variables and one interview observation variable were also found to be…

  6. The fish fauna in the fish passage at the Ourinhos Dam, Paranapanema River

    Marlene Sofia Arcifa

    2012-10-01

    Full Text Available The composition and abundance of the fish assemblage were evaluated in the fish ladder of Ourinhos Dam, the newest dam (closed in 2005 in the cascade of dams constructed on the Paranapanema River. Samplings were carried out three times on a diel cycle, in three sampling periods, two in the warm season and one in the cold season of 2008 - 2009. The ladder was closed and emptied and the entire fish assemblage was sampled and identified. Most individuals were released alive downstream of the dam. The assemblage found in the ladder was compared with the fish fauna sampled in the reservoir and in downstream sites, in the same period. Twenty seven species and a total of 4682 individuals were caught in the ladder. Pimelodus maculatus was the only migratory species, which was caught in low number in the ladder (0.04% of the total captured, where small sedentary species predominated. The most abundant species were the non-migratory Apareiodon affinis, Bryconamericus stramineus, Astyanax fasciatus and Parodon nasus. Individuals observed in the ladder's window were moving up- and down the passage. The fish ladder is a microhabitat inhabited by an abundant association of benthic organisms that is probably used as a food resource for the fish assemblage in the ladder. The similarity between the fish fauna in the ladder and that of the Ourinhos Reservoir was low (26%. The species richness of migrants in the stretch between the uspstream reservoir (Chavantes and the downstream one (Salto Grande, before the Ourinhos dam closure (23 species was reduced to 16 and 12 species in Salto Grande and Ourinhos reservoirs, respectively, after the dam closure, and to a single species in the ladder.A composição e abundância da ictiofauna da escada de peixes da barragem de Ourinhos, a mais nova hidrelétrica (fechada em 2005 na sequência de barragens construídas no rio Paranapanema, foram avaliadas três vezes em um ciclo diário, em três períodos de coleta, dois no

  7. PLUME collaboration: Ultra-light ladders for linear collider vertex detector

    The PLUME (Pixelated Ladder with Ultra-Low Material Embedding) Collaboration is developing ultra-light ladders for the vertex detector for a future linear collider. The double-sided ladder will integrate the sensors, readout infrastructure and mechanical supports with the aim of total material budget of 0.3% of radiation length. The requirement of as light as possible construction is driven by physics, in particular by measurements requiring determination of the quark charge sign. The first prototype ladders were prepared and tested in the beam. The alignment issues for the ladders will be tested within the AIDA (Advanced European Infrastructures for Detectors at Accelerators) EU FP7 project.

  8. Lock and Dam No. 9 : Arkansas River, Arkansas : Supplement No. 2 to Design Memorandum No. 1, General Fish and Wildlife Facilities at Holla Bend National Wildlife Refuge

    US Fish and Wildlife Service, Department of the Interior — This supplement is prepared in compliance with instructions included in 2d endorsement ENGCW-EZ dated 9 June 1965 to the transmittal letter for Design Memorandum...

  9. Essential Fish Habitat (EFH) Areas Protected From Fishing

    National Oceanic and Atmospheric Administration, Department of Commerce — Designated Essential Fish Habitat (EFH) areas where fishing or the use of fishing gears has been restricted or modified in order to minimize the adverse effects of...

  10. Changing How Schools and the Profession Are Organized: Building a Foundation for a National System of Teacher Career Ladders at the National Center on Education and the Economy

    Yang Keo, Seng-Dao

    2016-01-01

    This capstone examines the National Center on Education and the Economy’s (NCEE) efforts in its initial planning stage to lead the design of and build support for a proposed national system of teacher career ladders. In this career ladder system, teachers can voluntarily seek advanced certification leading up to the role of Master Teacher, and states can volunteer to use the system and determine how to use it. I describe my role in strengthening NCEE’s relationship with the National Board for...

  11. Means – End Chain Theory and Laddering Technique: Applications in Consumer Behavior Research

    Ayca Kangal

    2013-04-01

    Full Text Available Means – end chain (MEC theory and laddering technique uncovers the decision making process of consumers related to marketing offerings such as goods, services and experiences in a cognitive approach from a consumer perspective view which are popularly used approaches in marketing context. The purpose of the study is to discusss and present the laddering techique to Turkish literature, which is a frequently used qualitative research method in consumer behavior, both with related theoretical structure and practice. With this purpose, the overview of the literature within the frame of means – end chain theory, practices in consumer behavior, laddering technique, data collection, data analyze and interperation steps, limits of the laddering technique and alternatives of soft laddering (hard laddering is discussed. Laddering technique among with alternative data collection tools are anticipated Turkish researchers’ interest.

  12. Dissipation, voltage profile and Levy dragon in a special ladder network

    A ladder network constructed by an elementary two-terminal network consisting of a parallel resistor-inductor block in series with a parallel resistor-capacitor block sometimes is said to have a non-dispersive dissipative response. This special ladder network is created iteratively by replacing the elementary two-terminal network in place of the resistors. In this paper, it will be demonstrated that, in fact, non-dispersive dissipative response conclusion of this special ladder network is not accurate for steady-state condition. Furthermore, the voltage profile of this special ladder network exhibits a fractal form called the Levy C curve or Levy dragon in a certain condition. Therefore, this special ladder network may be called the Levy ladder network. This ladder network might be interesting for physics and electrical engineering students and they may encounter when dealing with this network series and parallel combinations of impedances.

  13. Meet the surrogate fish

    This article gives details of the US Department of Energy's innovative research into the development of a sensor system that will work as a surrogate fish to provide information to aid the design of fish-friendly turbines for hydroelectric power plants. The selection of the dams for the testing of sensor fish, the release and recovery of the sensor fish, the recording of the physical forces exerted on fish as they pass through the turbines, and use of the information gathered to build more sensor fish are discussed. Fish investigations conducted at the Pacific Northwest National Laboratory are briefly described. (UK)

  14. Geometric Summary of the 9 Chip Ladder for the D0 Silicon Tracker

    Two hybrids types are required to accomodate the flipping of ladders within each bulkhead layer, in order to account for the pigtail routing. Left and right versions are shown below, following the definitions laid out by Mike Matulik. These drawings are not to proper scale in the sketches below. The dimensionally correct versions of the 9 chip hybrids are stored in DCS under drawing number 3823.112-MD-317803 for the lefthanded version, and 3823.112-MD-317804 for the right handed version. Handedness of the hybrids are designated as shown in the figures and table below. There are long and short versions of both the left and the right, for four total 9 chip hdi designs. The pigtail lengths of the long and short are shown in a table in the hybrid drawings which reside in DCS. The chamfer in the hybrid corners (N side) is placed in order to enable the hybrid to be glued to the beryllium substrate, whereas the rectangular cuttout on the same side is to allow direct gluing of a temperature sensor to the substrate metal. The oblong shape on the N side of both hybrids is a 'stay-clear' region (defined in the final drawings) where pressure will be applied to the hybrid during the second stage of ladder construction.

  15. Method- and species-specific detection probabilities of fish occupancy in Arctic lakes: Implications for design and management

    Haynes, Trevor B.; Rosenberger, Amanda E.; Lindberg, Mark S.; Whitman, Matthew; Schmutz, Joel A.

    2013-01-01

    Studies examining species occurrence often fail to account for false absences in field sampling. We investigate detection probabilities of five gear types for six fish species in a sample of lakes on the North Slope, Alaska. We used an occupancy modeling approach to provide estimates of detection probabilities for each method. Variation in gear- and species-specific detection probability was considerable. For example, detection probabilities for the fyke net ranged from 0.82 (SE = 0.05) for least cisco (Coregonus sardinella) to 0.04 (SE = 0.01) for slimy sculpin (Cottus cognatus). Detection probabilities were also affected by site-specific variables such as depth of the lake, year, day of sampling, and lake connection to a stream. With the exception of the dip net and shore minnow traps, each gear type provided the highest detection probability of at least one species. Results suggest that a multimethod approach may be most effective when attempting to sample the entire fish community of Arctic lakes. Detection probability estimates will be useful for designing optimal fish sampling and monitoring protocols in Arctic lakes.

  16. NEW DESIGN FOR AIRLIFT PUMP USED IN FISH CULTURE TANKS WITH THE ENDANGERED RIO GRANDE SILVERY MINNOW (Hybognathus amarus)

    Hutson, Alison M.; Lawrence Valenzuela; Douglas Tave; Louie Toya

    2012-01-01

    This article describes an airlift pump used to produce a circular flow in a fish culture tank that does not attach to the tank. The design produces an airlift pump that does not swing back and forth or float upwards while in use. It is easy to build, inexpensive, and can be quickly installed and removed so that it does not interfere with sampling or harvest. The airlift pump was evaluated during a 30-d survival trial with the endangered Rio Grande silvery minnow (Hybognathus amarus) in 2.44-m...

  17. Phase diagram of a bosonic ladder with two coupled chains

    We study a bosonic ladder with two coupled chains using the finite-size density-matrix renormalization group method. We show that in a commensurate bosonic ladder the critical on-site interaction (UC) for the superfluid to Mott insulator transition gets larger as the interchain hopping (tperpendicular) increases. We analyze this quantum phase transition and obtain the phase diagram in the tperpendicular-U plane. We also consider the asymmetric case where the on-site interactions are different in the two chains and have shown that the system as a whole will not be in the Mott insulator phase unless both the chains have on-site interactions greater than the critical value

  18. Kinetic Simulations of Ladder Climbing and Autoresonance of Plasma Waves

    Kaminski, Erez; Barth, Ido; Fisch, Nat; Dodin, Ilya

    2015-11-01

    Quantum like Ladder Climbing and Autoresonance of classical Langmuir waves in bounded plasmas are numerically studied within a kinetic model and compared with earlier fluid model simulations. Both dynamical solutions are excited and controlled via chirped modulations of the background density that preserve the plasma wave quanta. Landau damping determines the system's maximal stable level, imposing a kinetic limit on the maximal level of the Ladder Climbing or Autoresonance dynamics. Vlasov simulations are employed to test the kinetic stability of both dynamics and to find the kinetic limit for different system's parameters. This work was Supported by NNSA grant DE274-FG52-08NA28553, DOE contract DE-AC02-09CH11466, and DTRA grant HDTRA1-11-1-0037.

  19. Falling off the Ladder - Earnings Losses from Job Loss

    Gregor Jarosch

    2014-01-01

    Job loss translates into large and persistent earnings reductions. Using a large administrative dataset from Germany, I document that this reflects both a reduced employment rate and reduced wages, with the recovery in wages being particularly slow. To account for these facts, I build a search model of the labor market in which workers climb an earnings ladder along multiple dimensions. They search for increasingly productive and secure jobs, accumulate general human capital, and extract rent...

  20. Laplace-Runge-Lenz vector, ladder operators and supersymmetry

    We show that the Laplace-Runge-Lenz vector (LRLV) generates the Infeld-Hull radial factorization and the pair of isospectral Hamiltonians for the non-relativistic Kepler-Coulomb quantum problem. To do this we only use the LRLV and arguments of general soundness. Finally, the well known restrictions on the orbital angular momentum and the principal quantum numbers are rederived from the corresponding ladder operators. (author)

  1. Chain ladder method: Bayesian bootstrap versus classical bootstrap

    Peters, Gareth W.; Mario V. W\\"uthrich; Shevchenko, Pavel V.

    2010-01-01

    The intention of this paper is to estimate a Bayesian distribution-free chain ladder (DFCL) model using approximate Bayesian computation (ABC) methodology. We demonstrate how to estimate quantities of interest in claims reserving and compare the estimates to those obtained from classical and credibility approaches. In this context, a novel numerical procedure utilising Markov chain Monte Carlo (MCMC), ABC and a Bayesian bootstrap procedure was developed in a truly distribution-free setting. T...

  2. Two-point resistance of the Möbius ladder

    Exact formulas for the two-point resistance and the Kirchhoff index of the Möbius ladder are given based on the recently developed analytical approach by Chair (2012 Ann. Phys. 327 2899). The expression for the two-point resistance is written in terms of the two-point resistance of N/2-cycle graph and the Bejaia and the Pisa numbers recently introduced by the first author. (paper)

  3. Transport coefficients and ladder summation in hot gauge theories

    Basagoiti, Manuel A. Valle

    2002-01-01

    We show how to compute transport coefficients in gauge theories by considering the expansion of the Kubo formulas in terms of ladder diagrams in the imaginary time formalism. All summations over Matsubara frequencies are performed and the analytical continuation to get the retarded correlators is done. As an illustration of the procedure, we present a derivation of the transport equation for the shear viscosity in the scalar theory. Assuming the Hard Thermal Loop approximation for the screeni...

  4. Hole-doping effects on a frustrated spin ladder

    Kawaguchi, Akira; Koga, Akihisa; Okunishi, Kouichi; Kawakami, Norio

    2002-01-01

    Hole-doping effects are investigated on the {\\it t-J} ladder model with the linked-tetrahedra structure. We discuss how a metal-insulator transition occurs upon hole doping with particular emphasis on the effects of geometrical frustration. By computing the electron density and the spin correlation function by the density matrix renormalization group, we show that strong frustration triggers a first-order transition to a metallic phase, when holes are doped into the plaquette-singlet phase. B...

  5. Design and application of a fish-shaped lateral line probe for flow measurement.

    Tuhtan, J A; Fuentes-Pérez, J F; Strokina, N; Toming, G; Musall, M; Noack, M; Kämäräinen, J K; Kruusmaa, M

    2016-04-01

    We introduce the lateral line probe (LLP) as a measurement device for natural flows. Hydraulic surveys in rivers and hydraulic structures are currently based on time-averaged velocity measurements using propellers or acoustic Doppler devices. The long-term goal is thus to develop a sensor system, which includes spatial gradients of the flow field along a fish-shaped sensor body. Interpreting the biological relevance of a collection of point velocity measurements is complicated by the fact that fish and other aquatic vertebrates experience the flow field through highly dynamic fluid-body interactions. To collect body-centric flow data, a bioinspired fish-shaped probe is equipped with a lateral line pressure sensing array, which can be applied both in the laboratory and in the field. Our objective is to introduce a new type of measurement device for body-centric data and compare its output to estimates of conventional point-based technologies. We first provide the calibration workflow for laboratory investigations. We then provide a review of two velocity estimation workflows, independent of calibration. Such workflows are required as existing field investigations consist of measurements in environments where calibration is not feasible. The mean difference for uncalibrated LLP velocity estimates from 0 to 50 cm/s under in a closed flow tunnel and open channel flume was within 4 cm/s when compared to conventional measurement techniques. Finally, spatial flow maps in a scale vertical slot fishway are compared for the LLP, direct measurements, and 3D numerical models where it was found that the LLP provided a slight overestimation of the current velocity in the jet and underestimated the velocity in the recirculation zone. PMID:27131710

  6. Design and application of a fish-shaped lateral line probe for flow measurement

    Tuhtan, J. A.; Fuentes-Pérez, J. F.; Strokina, N.; Toming, G.; Musall, M.; Noack, M.; Kämäräinen, J. K.; Kruusmaa, M.

    2016-04-01

    We introduce the lateral line probe (LLP) as a measurement device for natural flows. Hydraulic surveys in rivers and hydraulic structures are currently based on time-averaged velocity measurements using propellers or acoustic Doppler devices. The long-term goal is thus to develop a sensor system, which includes spatial gradients of the flow field along a fish-shaped sensor body. Interpreting the biological relevance of a collection of point velocity measurements is complicated by the fact that fish and other aquatic vertebrates experience the flow field through highly dynamic fluid-body interactions. To collect body-centric flow data, a bioinspired fish-shaped probe is equipped with a lateral line pressure sensing array, which can be applied both in the laboratory and in the field. Our objective is to introduce a new type of measurement device for body-centric data and compare its output to estimates of conventional point-based technologies. We first provide the calibration workflow for laboratory investigations. We then provide a review of two velocity estimation workflows, independent of calibration. Such workflows are required as existing field investigations consist of measurements in environments where calibration is not feasible. The mean difference for uncalibrated LLP velocity estimates from 0 to 50 cm/s under in a closed flow tunnel and open channel flume was within 4 cm/s when compared to conventional measurement techniques. Finally, spatial flow maps in a scale vertical slot fishway are compared for the LLP, direct measurements, and 3D numerical models where it was found that the LLP provided a slight overestimation of the current velocity in the jet and underestimated the velocity in the recirculation zone.

  7. Phase diagrams of spinor bosons in two-leg ladders

    Silva Valencia, Jereson; Franco, Roberto; Figueira, Marcos Sergio

    In the last, years different experimental groups have reported the realization of atomic ladders in the presence of a homogeneous flux [Nat. Phys. 10, 588 (2014)]. These experiments have motivated theoretical calculations on 2-leg ladders with spinless bosons under magnetic fields [PRB 91, 140406(R) (2015)]. In this paper, we consider spinor boson atoms with spin S =1, such as Rb and Na. Gases of these atoms can be described by the spinor Bose-Hubbard Hamiltonian which has three terms: the kinetic energy, local density-density interaction and local spin-dependent term. Using DMRG, we study S =1 bosons on 2-leg ladders, taking into account bothantiferromagnetic and ferromagneticspin interaction. When both legs are ferromagnetic or antiferromagnetic, we obtained Mott insulator and superfluid phases, similar to the one-dimensional case, but the insulator areas decrease due to the additional kinetic term. The even-odd asymmetry is still observed in the antiferromagnetic case. However, when the local spin interaction has a different sign on each leg, charge density waves for densities 3/2 and 5/2 appear. The Mott insulator phase for density 1 (2) correspond to the antiferromagnetic-leg (ferromagnetic-leg). COLCIENCIAS (Grant No. FP44842-057-2015).

  8. The search for competing charge orders in frustrated ladder systems

    A recent study revealed the dynamics of the charge sector of a one-dimensional quarter- filled electronic system with extended Hubbard interactions to be that of an effective pseudospin transverse-field Ising model (TFIM) in the strong coupling limit. With the twin motivations of studying the co-existing charge and spin order found in strongly correlated chain systems and the effects of inter-chain couplings, we investigate the phase diagram of coupled effective (TFIM) systems. A bosonisation and RG analysis for a two-leg TFIM ladder yields a rich phase diagram showing Wigner/Peierls charge order and Neel/dimer spin order. In a broad parameter regime, the orbital antiferromagnetic phase is found to be stable. An intermediate gapless phase of finite width is found to lie in between two charge-ordered gapped phases. Kosterlitz-Thouless transitions are found to lead from the gapless phase to either of the charge-ordered phases. Low energy effective Hamiltonian analyses of a strongly coupled 2-chain ladder system confirm a phase diagram with in-chain CO, rung-dimer, and orbital antiferromagnetic ordered phases with varying interchain couplings as well as superconductivity upon hole-doping. Our work is potentially relevant for a unified description of a class of strongly correlated, quarter-filled chain and ladder systems. (autor)

  9. NEW DESIGN FOR AIRLIFT PUMP USED IN FISH CULTURE TANKS WITH THE ENDANGERED RIO GRANDE SILVERY MINNOW (Hybognathus amarus

    Alison M. Hutson

    2012-10-01

    Full Text Available This article describes an airlift pump used to produce a circular flow in a fish culture tank that does not attach to the tank. The design produces an airlift pump that does not swing back and forth or float upwards while in use. It is easy to build, inexpensive, and can be quickly installed and removed so that it does not interfere with sampling or harvest. The airlift pump was evaluated during a 30-d survival trial with the endangered Rio Grande silvery minnow (Hybognathus amarus in 2.44-m-diameter circular tanks (3,666 l. Because the fish is endangered, all new culture units must be evaluated in a survival trial. To be able to use a new 15-tank system, survival had to be evaluated in a random representation of three tanks. U.S. Fish and Wildlife Service, which regulates all activities with this endangered species, decided that permitted take (maximum permitted mortality was 60% for the survival trial; consequently, survival >40% in each tank would be considered successful. Two airlift pumps were placed in each tank. The two airlift pumps moved a mean±SD of 33.697±5.563 l/min; this produced total tank turnovers through the airlift pumps of 110.65±16.93 min. Water velocities were measured at nine locations in the tanks. Water velocities were 0.0-0.04 m/sec. Dissolved oxygen concentration never went below 6.30 mg/l. The airlift pumps operated flawlessly and required no maintenance. They produced water velocities preferred by the fish and helped keep dissolved oxygen concentration above the permitted minimum (5 mg/l. The airlift pumps will be used in future fish culture activities in these and other tanks. Survival in the three tanks was 78%, 94% and 96%; overall survival was 89.3%. Because take (10.7% was under the permitted level (60%, the trial was successful.

  10. New Design of Crypto-Based Pseudo random number generator (CBPRNG using BLOW FISH cipher

    T.Chalama Reddy

    2013-06-01

    Full Text Available Random Number Generators (RNGs are an important building block for algorithms and protocols in cryptography. Random number generation is used in a wide variety of cryptographic operations, such as key generation and challenge/response protocols. A random number generator outputs a sequence of 0s and 1s such that at any position, the next bit cannot be expected on the previous bits. However, true random number produces non- deterministic output since if the same random generator is run twice, identical results are not received. Thus we go for pseudo random number generator that is deterministic device because if this random number generator is run twice or more, it gives same results. Our paper presents new crypto based pseudorandom number generator. It uses BLOW FISH ciphers and the Cipher-Block chaining (CBC mode that uses three stages of the block chaining. The plain text for each stage comes from the output of the first BLOW FISH, which uses the 64-Bit date and time as the plain text. CBPRNG creates three 64-bit random numbers, the first and the second are concatenated to create a 128-random number and the third is used as next initial vector (IV for CBPRNG. Our Crypto-Based Pseudo-random Number Generator produces a sequence of bits that has arandom looking distribution. This new generator helps to develop huge range cryptographic applications to increase the system security. A number of applications such as financial security applications and Pretty Good Privacy (PGP use this technique.

  11. Electronic transport through a ladder nano structure in the presence of network defects

    The present research studied the electronic transport of an ideal infinite ladder nano structure in the presence/absence of network defects by using Green's function method at the tight-binding approximation. The network defects can be simulated by considering a finite ladder which is connected via two contacts to two similar infinite ladders. The results showed that the hopping energy of rungs determines the overlapping region of the ladder conductance channels. By increasing hopping energy of rungs, the allowed energy region of the ladder increases, while the overlapping region shrinks and eventually vanishes. Creation of branched bonds in the center ladder leads, through the system, to a harder electron tunneling. Moreover, the closer electron energy to the system gap edges leads to a better tunneling.

  12. Design and characterization of self-assembled fish sarcoplasmic protein-alginate nanocomplexes

    Boutrup Stephansen, Karen; Mattebjerg, Maria Ahlm; Wattjes, Jasper;

    2015-01-01

    Macrostructures based on natural polymers are subject to large attention, as the application range is wide within the food and pharmaceutical industries. In this study we present nanocomplexes (NCXs) made from electrostatic self-assembly between negatively charged alginate and positively charged...... caused a decreased viability in HeLa and U2OS cell lines. The simple processing procedure and the high stability of the NCXs, makes them excellent candidates for use in the food and pharmaceutical industry. (C) 2015 Elsevier B.V. All rights reserved....... fish sarcoplasmic proteins (FSP), prepared by bulk mixing. A concentration screening revealed that there was a range of alginate and FSP concentrations where stable NCXs with similar properties were formed, rather than two exact concentrations. The size of the NCXs was 293 +/- 3 nm, and the zeta...

  13. Design and application of two oligonucleotide probes for the identification of Geodermatophilaceae strains using fluorescence in situ hybridization (FISH).

    Urzì, Clara; La Cono, Violetta; Stackebrandt, Erko

    2004-07-01

    Bacteria of the family of Geodermatophilaceae are actively involved in the decay processes [Urzì, C. and Realini, M. (1998) Int Biodeterior Biodegrad 42: 45-54; Urzì, C., Salamone, P., Schumann, P., and Stackebrandt, E. (2000) Int J Syst Evol Microbiol 50: 529-536] of stone monuments. Characterization of isolates includes phenotypic, chemotaxonomic and genetic analysis often requiring long-term procedures. The use of specific probes for members of Geodermatophilaceae family could be useful for the easy detection of those strains colonizing rock surfaces and involved in the biodeterioration. Two 16S rRNA-targeted oligonucleotide probes were designed for the specific detection of members of the family Geodermatophilaceae using fluorescence in situ hybridization (FISH); one probe specific for members of the two genera Geodermatophilus/Blastococcus and the second for members of the genus Modestobacter. PMID:15186346

  14. Design and performance of radio telemetry systems for assessing juvenile fish passage at three hydroelectric dams: Chapter 6.5

    Beeman, John W.; Hockersmith, Eric; Stevenson, John R.

    2012-01-01

    Telemetry provides a powerful and flexible tool for studying fish and other aquatic animals, and its use has become increasingly commonplace. However, telemetry is gear intensive and typically requires more specialized knowledge and training than many other field techniques. As with other scientific methods, collecting good data is dependent on an understanding of the underlying principles behind the approach, knowing how to use the equipment and techniques properly, and recognizing what to do with the data collected. This book provides a road map for using telemetry to study aquatic animals, and provides the basic information needed to plan, implement, and conduct a telemetry study under field conditions. Topics include acoustic or radio telemetry study design, tag implantation techniques, radio and acoustic telemetry principles and case studies, and data management and analysis.

  15. Fish schooling as a basis for vertical axis wind turbine farm design.

    Whittlesey, Robert W; Liska, Sebastian; Dabiri, John O

    2010-09-01

    Most wind farms consist of horizontal axis wind turbines (HAWTs) due to the high power coefficient (mechanical power output divided by the power of the free-stream air through the turbine cross-sectional area) of an isolated turbine. However when in close proximity to neighboring turbines, HAWTs suffer from a reduced power coefficient. In contrast, previous research on vertical axis wind turbines (VAWTs) suggests that closely spaced VAWTs may experience only small decreases (or even increases) in an individual turbine's power coefficient when placed in close proximity to neighbors, thus yielding much higher power outputs for a given area of land. A potential flow model of inter-VAWT interactions is developed to investigate the effect of changes in VAWT spatial arrangement on the array performance coefficient, which compares the expected average power coefficient of turbines in an array to a spatially isolated turbine. A geometric arrangement based on the configuration of shed vortices in the wake of schooling fish is shown to significantly increase the array performance coefficient based upon an array of 16 x 16 wind turbines. The results suggest increases in power output of over one order of magnitude for a given area of land as compared to HAWTs. PMID:20729568

  16. Fish schooling as a basis for vertical axis wind turbine farm design

    Most wind farms consist of horizontal axis wind turbines (HAWTs) due to the high power coefficient (mechanical power output divided by the power of the free-stream air through the turbine cross-sectional area) of an isolated turbine. However when in close proximity to neighboring turbines, HAWTs suffer from a reduced power coefficient. In contrast, previous research on vertical axis wind turbines (VAWTs) suggests that closely spaced VAWTs may experience only small decreases (or even increases) in an individual turbine's power coefficient when placed in close proximity to neighbors, thus yielding much higher power outputs for a given area of land. A potential flow model of inter-VAWT interactions is developed to investigate the effect of changes in VAWT spatial arrangement on the array performance coefficient, which compares the expected average power coefficient of turbines in an array to a spatially isolated turbine. A geometric arrangement based on the configuration of shed vortices in the wake of schooling fish is shown to significantly increase the array performance coefficient based upon an array of 16 x 16 wind turbines. The results suggest increases in power output of over one order of magnitude for a given area of land as compared to HAWTs.

  17. Fish schooling as a basis for vertical axis wind turbine farm design

    Whittlesey, Robert W; Liska, Sebastian; Dabiri, John O, E-mail: robertw@caltech.ed, E-mail: jodabiri@caltech.ed [Graduate Aeronautical Laboratories, California Institute of Technology, 1200 E California Blvd, MC 205-45, Pasadena, CA 91125 (United States)

    2010-09-15

    Most wind farms consist of horizontal axis wind turbines (HAWTs) due to the high power coefficient (mechanical power output divided by the power of the free-stream air through the turbine cross-sectional area) of an isolated turbine. However when in close proximity to neighboring turbines, HAWTs suffer from a reduced power coefficient. In contrast, previous research on vertical axis wind turbines (VAWTs) suggests that closely spaced VAWTs may experience only small decreases (or even increases) in an individual turbine's power coefficient when placed in close proximity to neighbors, thus yielding much higher power outputs for a given area of land. A potential flow model of inter-VAWT interactions is developed to investigate the effect of changes in VAWT spatial arrangement on the array performance coefficient, which compares the expected average power coefficient of turbines in an array to a spatially isolated turbine. A geometric arrangement based on the configuration of shed vortices in the wake of schooling fish is shown to significantly increase the array performance coefficient based upon an array of 16 x 16 wind turbines. The results suggest increases in power output of over one order of magnitude for a given area of land as compared to HAWTs.

  18. Ladder operators and recursion relations for the associated Bessel polynomials

    Introducing the associated Bessel polynomials in terms of two non-negative integers, and under an integrability condition we simultaneously factorize their corresponding differential equation into a product of the ladder operators by four different ways as shape invariance symmetry equations. This procedure gives four different pairs of recursion relations on the associated Bessel polynomials. In spite of description of Bessel and Laguerre polynomials in terms of each other, we show that the associated Bessel differential equation is factorized in four different ways whereas for Laguerre one we have three different ways

  19. Ladder operators and recursion relations for the associated Bessel polynomials

    Fakhri, H.; Chenaghlou, A.

    2006-10-01

    Introducing the associated Bessel polynomials in terms of two non-negative integers, and under an integrability condition we simultaneously factorize their corresponding differential equation into a product of the ladder operators by four different ways as shape invariance symmetry equations. This procedure gives four different pairs of recursion relations on the associated Bessel polynomials. In spite of description of Bessel and Laguerre polynomials in terms of each other, we show that the associated Bessel differential equation is factorized in four different ways whereas for Laguerre one we have three different ways.

  20. Ladder operators and recursion relations for the associated Bessel polynomials

    Fakhri, H. [Institute for Studies in Theoretical Physics and Mathematics (IPM), PO Box 19395-5531, Tehran (Iran, Islamic Republic of) and Department of Theoretical Physics and Astrophysics, Physics Faculty, Tabriz University, PO Box 51666-16471, Tabriz (Iran, Islamic Republic of)]. E-mail: hfakhri@ipm.ir; Chenaghlou, A. [Institute for Studies in Theoretical Physics and Mathematics (IPM), PO Box 19395-5531, Tehran (Iran, Islamic Republic of) and Physics Department, Faculty of Science, Sahand University of Technology, PO Box 51335-1996, Tabriz (Iran, Islamic Republic of)]. E-mail: a.chenaghlou@sut.ac.ir

    2006-10-30

    Introducing the associated Bessel polynomials in terms of two non-negative integers, and under an integrability condition we simultaneously factorize their corresponding differential equation into a product of the ladder operators by four different ways as shape invariance symmetry equations. This procedure gives four different pairs of recursion relations on the associated Bessel polynomials. In spite of description of Bessel and Laguerre polynomials in terms of each other, we show that the associated Bessel differential equation is factorized in four different ways whereas for Laguerre one we have three different ways.

  1. Optimal molecular alignment and orientation through rotational ladder climbing

    Salomon, J; Turinici, G; Salomon, Julien; Dion, Claude M.; Turinici, Gabriel

    2005-01-01

    We study the control by electromagnetic fields of molecular alignment and orientation, in a linear, rigid rotor model. With the help of a monotonically convergent algorithm, we find that the optimal field is in the microwave part of the spectrum and acts by resonantly exciting the rotation of the molecule progressively from the ground state, i.e., by rotational ladder climbing. This mechanism is present not only when maximizing orientation or alignment, but also when using prescribed target states that simultaneously optimize the efficiency of orientation/alignment and its duration.

  2. Yang-Lee Circle Theorem for an Antiferromagnetic Heisenberg Ladder

    王先智

    2001-01-01

    The Yang-Lee zeros of an antiferromagnetic Heisenberg ladder model are determined. It is found that if J4≤0 Yang-Lee zeros are located on the unit circle and on the negative real axis in the complex activity plane. In particular, if J4≤0 and 2J2≥J4, Yang-Lee zeros are located on the unit circle and the Yang-Lee circle theorem is valid. If J4 > 0, Yang-Lee zeros are located on some complicated curves.

  3. Beyond rainbow-ladder in bound state equations

    In this work we devise a new method to study quark-anti-quark interactions beyond simple ladder-exchange that yield massless pions in the chiral limit. The method is based on the requirement to have a representation of the quark-gluon vertex that is explicitly given in terms of quark dressings functions. We outline a general procedure to generate the Bethe-Salpeter kernel for a given vertex representation. Our method allows not only the identification of the mesons' masses but also the extraction of their Bethe-Salpeter wave functions exposing their internal structure. We exemplify our method with vertex models that are of phenomenological interest. (orig.)

  4. The World Health Organisation analgesic ladder: its place in modern Irish medical practice.

    Balding, L

    2013-04-01

    Pain is the single most common reason why patients seek medical care. Worldwide, there are 10 million new cases of cancer each year, with 6 million deaths annually. The World Health Organisation (WHO) first published Cancer Pain Relief in 1986, designed to be a simple, intuitive and accessible guide to the management of cancer pain that would be applicable and useful whatever the language, culture, economy, country and clinical setting. In Ireland today, we have ready access to many different opioids, and the WHO guidelines may seem inadequate and outdated. This article describes the evolution and use of the WHO guidelines, as viewed from the global perspective of its 193 member nations. The WHO ladder still remains valid today in Ireland, even as we await the imminent publication of new evidence-based national cancer pain guidelines this year. PMID:23691849

  5. Fish Allergy

    ... Story" 5 Things to Know About Zika & Pregnancy Fish Allergy KidsHealth > For Parents > Fish Allergy Print A ... From Home en español Alergia al pescado About Fish Allergy A fish allergy is not exactly the ...

  6. Carrer Ladder Reform: A Multi-Level Analysis of Initial Efforts.

    Malen, Betty; Hart, Ann Weaver

    1987-01-01

    Interpretation, assimilation, and adjustment to the Utah Career Ladder Program and the extent to which these responses reflect fundamental changes in the structure of teacher work were assessed. Promotional positions and differentiated salaries--distinctive features of a career ladder--were being compromised at all levels of the system. (SLD)

  7. New polysilsesquioxane materials of ladder-like structure

    Handke, M.; Handke, B.; Kowalewska, A.; Jastrzębski, W.

    2009-04-01

    Alkoxy derivatives of linear oligomethylsiloxanes were applied as substrates for preparation of novel type, ladder-like polymeric silsesquioxane-siloxane materials. A systematic study of the effect of diverging the structure of a polysiloxane chain (distribution of alkoxysilyl groups along the polymer chain) on the properties of silsesquioxane materials obtained by condensation of ethoxy groups, has been undertaken. A series of polysiloxane materials cross-linked with -SiOSi- bonds, forming ladder-like linkages between main siloxane chains was prepared. There were used siloxanes of a regular structure with formula [M(D 2D OR) 10D 2M] and [M(D 2D OR2) 10D 2M] ] as well as siloxane oligomers of random distribution of MeSi-OR (D OR) units along the main siloxane chain [MD (1-x)D ORxM ( x = 0.3, 0.5, 1.0)]. Alkoxy-functionalized oligosiloxane precursors were cross-linked under hydrolytic condensation conditions catalyzed by HCl/NH 4OH system or nucleophilic catalysts (TBAF and TBAH). The relationship between the structure of siloxane chain (the amount of Si-OR units and their distribution along the polymer backbone) and the properties of obtained preceramic materials was studied with FTIR (as a main method) and NMR, XRD, DTA. The surface area and pores distributions of the studied samples were measured using nitrogen adsorption methods (BET).

  8. PNA-COMBO-FISH: From combinatorial probe design in silico to vitality compatible, specific labelling of gene targets in cell nuclei.

    Müller, Patrick; Rößler, Jens; Schwarz-Finsterle, Jutta; Schmitt, Eberhard; Hausmann, Michael

    2016-07-01

    Recently, advantages concerning targeting specificity of PCR constructed oligonucleotide FISH probes in contrast to established FISH probes, e.g. BAC clones, have been demonstrated. These techniques, however, are still using labelling protocols with DNA denaturing steps applying harsh heat treatment with or without further denaturing chemical agents. COMBO-FISH (COMBinatorial Oligonucleotide FISH) allows the design of specific oligonucleotide probe combinations in silico. Thus, being independent from primer libraries or PCR laboratory conditions, the probe sequences extracted by computer sequence data base search can also be synthesized as single stranded PNA-probes (Peptide Nucleic Acid probes). Gene targets can be specifically labelled with at least about 20 PNA-probes obtaining visibly background free specimens. By using appropriately designed triplex forming oligonucleotides, the denaturing procedures can completely be omitted. These results reveal a significant step towards oligonucleotide-FISH maintaining the 3d-nanostructure and even the viability of the cell target. The method is demonstrated with the detection of Her2/neu and GRB7 genes, which are indicators in breast cancer diagnosis and therapy. PMID:27237093

  9. 49 CFR 214.519 - Floors, decks, stairs, and ladders of on-track roadway maintenance machines.

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Floors, decks, stairs, and ladders of on-track... SAFETY On-Track Roadway Maintenance Machines and Hi-Rail Vehicles § 214.519 Floors, decks, stairs, and ladders of on-track roadway maintenance machines. Floors, decks, stairs, and ladders of on-track...

  10. Design and Analysis of an Underwater White LED Fish-Attracting Lamp and Its Light Propagation

    Sheng Chih Shen

    2013-03-01

    Full Text Available Light emitting diodes (LED are a new source for replacing traditional light sources including under water illumination. As traditional underwater light sources operate under a radiative transfer model, the luminous intensity is dispersed evenly at each emission angle, with the scattering factors included in the attenuation coefficient. By contrast, LED light sources are characterized by being highly directional, causing underwater luminous energy to vary with different emission angles. Thus, the traditional theory of underwater optical transfer becomes inapplicable when an underwater LED lighting module is designed. Therefore, to construct an underwater transfer model for LED light sources, this study employed the average cosine of the underwater light field, the method for light scattering probability, the LED luminous intensity distribution curve (LIDC and axial luminous intensity. Afterwards, an underwater LED fish‐attracting lamp was designed. Experimental results showed that, compared with the simulation values, the luminous intensity of the underwater LED lighting module at all emission angles had a percentage error of less than 10%.

  11. 基于舵机控制的仿生鱼设计%Bionics fish-based design of steering gear control

    卢亚平; 宋天麟

    2011-01-01

    In this paper,the characteristics of fish swimming and biomimetic robotic fish significance of research for the purpose。Based on the working principle of steering gear,this paper puts forward autonomous obstacle-avoiding of biomimetic fish design scheme.A%为实现仿生机器鱼的设计,分析鱼类游动的特点,基于舵机的工作原理,提出了自主避障的仿生鱼设计方案。根据鱼类推进理论,对仿生鱼进行了机械结构设计、软件设计。

  12. Characterising reef fish populations and habitats within and outside the US Virgin Islands Coral Reef National Monument: A lesson in marine protected area design

    Monaco, Mark E.; Friedlander, A.M.; Caldow, Chris; Christensen, J.D.; Rogers, C.; Beets, J.; Miller, J.; Boulon, Rafe

    2007-01-01

    Marine protected areas are an important tool for management of marine ecosystems. Despite their utility, ecological design criteria are often not considered or feasible to implement when establishing protected areas. In 2001, the Virgin Islands Coral Reef National Monument (VICRNM) in St John, US Virgin Islands was established by Executive Order. The VICRNM prohibits almost all extractive uses. Surveys of habitat and fishes inside and outside of the VICRNM were conducted in 2002-2004. Areas outside the VICRNM had significantly more hard corals, greater habitat complexity, and greater richness, abundance and biomass of reef fishes than areas within the VICRNM. The administrative process used to delineate the boundaries of the VICRNM did not include a robust ecological characterisation of the area. Because of reduced habitat complexity within the VICRNM, the enhancement of the marine ecosystem may not be fully realised or increases in economically important reef fishes may take longer to detect. ?? 2007 The Authors. Journal compilation ?? 2007 Blackwell Publishing Ltd.

  13. Helical quantum Hall edge modes in bilayer graphene: a realization of quantum spin-ladders

    Mazo, Victoria; Shimshoni, Efrat; Huang, Chia-Wei; Carr, Sam T.; Fertig, H. A.

    2015-10-01

    The rich phase diagram of quantum spin-ladder systems has attracted much attention in the theoretical literature. The progress in experimental realizations of this fascinating physics however has been much slower. While materials with a ladder-like structure exist, one always has coupling between the ladders to muddy the waters. In addition, such materials exhibit limited (if any) tunability in terms of the magnetic exchange parameters, and experimental probing of the different phases is a great challenge. In this work, we show that a realization of spin-ladder physics can occur in an engineered nanostructure made out of bilayer graphene in the ν =0 quantum Hall state. Specifically, we describe a split-double-gated setup in which a domain wall (DW) is explicitly induced in the middle of the sample, and show that an effective spin-ladder forms along this DW. The interaction strengths of the ladder are tunable by adjusting magnetic and electric fields as well as the spacing between the gates. Furthermore, we demonstrate that the effective spin ladder has a helical nature, meaning that the spin-correlations may be probed rather simply with charge transport experiments. We describe the phase diagram of this system, and show that certain transport measurements are very sensitive to the phase.

  14. Ward Identity Constraints on Ladder Kernels in Transport Coefficient Calculations

    Using diagrammatic methods, we show how the Ward identity can be used to constrain the ladder kernel in transport coefficients calculations. More specifically, we use the Ward identity to determine the necessary diagrams that must be resummed (using the usual integral equation). Our main result is an equation relating the kernel of the integral equation with functional derivatives of the full (imaginary) self-energy; it is similar to what is obtained with 2PI effective action methods. However, since we use the Ward identity as our starting point, gauge invariance is preserved. Using power counting arguments, we also show which self-energies must be included in the resummation at leading order, including 2 to 2 scatterings and 1 to 2 collinear scatterings with the Landau-Pomeranchuk-Migdal (LPM) effect. In this study we restrict our discussion to electrical conductivity and shear viscosity in QED, but our method can in principles be generalized to other transport coefficients and other theories

  15. Transport coefficients and ladder summation in hot gauge theories

    Valle-Basagoiti, M A

    2002-01-01

    We show how to compute transport coefficients in gauge theories by considering the expansion of the Kubo formulas in terms of ladder diagrams in the imaginary time formalism. All summations over Matsubara frequencies are performed and the analytical continuation to get the retarded correlators is done. As an illustration of the procedure, we present a derivation of the transport equation for the shear viscosity in the scalar theory. Assuming the Hard Thermal Loop approximation for the screening of distant collisions of the hard particles in the plasma, we derive a couple of integral equations for the effective vertices which, to logarithmic accuracy, are shown to be identical to the linearized Boltzmann equations previously found by Arnold, Moore and Yaffe.

  16. A General Study on Equivalent Resistance of Three-Terminal Ladder Network

    Wu Guoxiang; Tan Zhizhong; Song Guohua; Song Changqing

    2005-01-01

    In view of the application importance of resistance network in modern science and technology, the author presented the basic structure of a three-terminal ladder shaped resistance network and studied the equivalent resistance of the network. By means of virtual current method, the network was analyzed and a model of two elements three orders differential equation was constructed. Based on different marginal conditions, two general adaptive rules for the inlet resistance of the three-terminal ladder shaped network, as well as two ultimate rules for the equivalent resistance of three-terminal infinite ladder shaped network were given.

  17. Magnetism in the pseudo-two-leg ladder compound CaCu2O3

    Contrary to SrCu2O3, the pseudo-ladder two-leg compound CaCu2O3 does not show a significant spin-gap behavior as expected for typical two-leg ladder systems. Magnetization measurements on single crystals show CaCu2O3 to be a three-dimensional (3D) antiferromagnet (T N=27 K), showing relatively strong magnetic anisotropy and metamagnetic transitions. The 3D behavior is due to exchange between the ladders as deduced from electronic structure calculations within the local density approximation

  18. Means – End Chain Theory and Laddering Technique: Applications in Consumer Behavior Research

    Ayca Kangal

    2013-01-01

    Means – end chain (MEC) theory and laddering technique uncovers the decision making process of consumers related to marketing offerings such as goods, services and experiences in a cognitive approach from a consumer perspective view which are popularly used approaches in marketing context. The purpose of the study is to discusss and present the laddering techique to Turkish literature, which is a frequently used qualitative research method in consumer behavior, both with related theoretical s...

  19. Star formation relations across the CO ladder and redshift

    Greve, Thomas

    2015-08-01

    We present FIR-CO luminosity relations (i.e., log LFIR = α log LCO + β) for the full CO rotational ladder from J = 1-0 up to J = 13-12 for a sample of 62 local (z ≤ 0.1) (Ultra) Luminous Infrared Galaxies (LIRGs; LIR[8-1000 μm] > 1011 L⊙) using data from Herschel SPIRE-FTS and ground-based telescopes. We extend our sample to high redshifts (z > 1) by including 35 submillimeter selected dusty star forming galaxies from the literature with robust CO observations, and sufficiently well-sampled FIR/submillimeter spectral energy distributions (SEDs), so that accurate FIR luminosities can be determined. The addition of luminous starbursts at high redshifts enlarge the range of the FIR-CO luminosity relations toward the high-IR-luminosity end, while also significantly increasing the small amount of mid-J/high-J CO line data (J = 5-4 and higher) that was available prior to Herschel. This new data set (both in terms of IR luminosity and J-ladder) reveals linear FIR-CO luminosity relations (i.e., α ≈ 1) for J = 1-0 up to J = 5-4, with a nearly constant normalization (β ~ 2). In the simplest physical scenario, this is expected from the (also) linear FIR-(molecular line) relations recently found for the dense gas tracer lines (HCN and CS), as long as the dense gas mass fraction does not vary strongly within our (merger/starburst)-dominated sample. However, from J = 6-5 and up to the J = 13-12 transition, we find an increasingly sublinear slope and higher normalization constant with increasing J. We argue that these are caused by a warm (~100 K) and dense (>104 cm-3) gas component whose thermal state is unlikely to be maintained by star-formation-powered far-UV radiation fields (and thus is no longer directly tied to the star formation rate). We suggest that mechanical heating (e.g., supernova-driven turbulence and shocks), and not cosmic rays, is the more likely source of energy for this component. The global CO spectral line energy distributions, which remain

  20. Power Test of the Ladder IH-RFQ Accelerator at Peking University

    LU Yuan-Rong; CHEN Wei; NIE Yuan-Cun; LIU Ge; GAO Shu-Li; ZENG Hong-Jin; YAN Xue-Qing; CHEN Jia-Er

    2011-01-01

    A 104-MHz ladder interdigital-H radio frequency quadrupole accelerator (T-IH-RFQ) is developed for applying RFQs to heavy ion implantation and accelerator-based mass spectroscopy in recent years at the Institute of Heavy Ion Physics,Peking University.It could accelerate ions with a mass-to-charge ratio of less than 14,from 2.9 ke V/u to 35.7keV/u within a length of 1.1 m.The T-IH-RFQ cavity operating at H21(0) mode was constructed successfully.Based on a well designed rf power feeding system,the cavity was cold measured and tested with high rf power.In the case of cold measurement,the rf properties were obtained using a vector network analyzer with the help of a perturbation capacitor. During a high power test,the inter-electrode voltage was derived from the energy spectrum of x-rays measured by a high purity Ge detector.The results show that the specific shunt impedance of the T-IH-RFQ cavity reaches 178kΩm,which could meet the requirements of beam dynamics design.

  1. Multicriteria assessment in restoring migratory fish stocks in the river Iijoki; Monitavoitearviointi Iijoen vaelluskalakantojen palauttamisen tukena

    Karjalainen, T.P.; Rytkoenen, A.-M.; Marttunen, M.; Maeki-Petaeys, A.; Autti, O.

    2011-05-15

    The Iijoki is one of Finland's most important former salmon rivers. Construction of multiple main stem dams on the river in the 1960s effectively blocked the migration corridors of migratory fish. Suitable spawning and nursery habitats above the dams span an estimated 600-800 hectares. With riverside residents are very much in favour of the return of migratory fish, watershed planning for this has been set as a target. Such measures are rendered urgent by the fact that there is still a possibility of replenishing the Iijoki's own salmon stock, thereby restoring the fishes' natural lifecycle and natural selection. This report has been completed as part of the project 'The return of migratory fish to the River Iijoki (2008-2010)', where the main object was reconciling the target of enhancing the natural life cycle of migratory fish with the continued generation of hydropower. Under a multicriteria assessment, various alternatives and measures for improving migratory fish stocks were clarified and their desirability, costs and benefits systematically and transparently evaluated. Furthermore, interest groups' views of the three options and their effects (as distinct from the expert evaluation) were clarified with the help of computer aided interviews. The alternatives were transferring salmon above the main stem dams and two fish-ladder options. The multicriteria assessment viewed the construction of fish ladders, alongside other large-scale support measures, as the best option. Based on all of the criteria applied in a cost-benefit analysis, the stock transfer alternative was the most economically viable, because its net product value was positive in all cases. The fish ladder options were the most expensive due to the construction costs involved, but they also provided the greatest benefits. Above all, fish ladder construction is supported by the fact that it would return migratory fish to their natural lifecycle and attain the EU

  2. Mechanical Description of a Hyper-Redundant Robot Joint Mechanism Used for a Design of a Biomimetic Robotic Fish

    M. O. Afolayan

    2012-01-01

    Full Text Available A biologically inspired robot in the form of fish (mackerel model using rubber (as the biomimetic material for its hyper-redundant joint is presented in this paper. Computerized simulation of the most critical part of the model (the peduncle shows that the rubber joints will be able to take up the stress that will be created. Furthermore, the frequency-induced softening of the rubber used was found to be critical if the joints are going to oscillate at frequency above 25 Hz. The robotic fish was able to attain a speed of 0.985 m/s while the tail beats at a maximum of 1.7 Hz when tested inside water. Furthermore, a minimum turning radius of 0.8 m (approximately 2 times the fish body length was achieved.

  3. Ladder Operators for Lamé Spheroconal Harmonic Polynomials

    Ricardo Méndez-Fragoso

    2012-10-01

    Full Text Available Three sets of ladder operators in spheroconal coordinates and their respective actions on Lamé spheroconal harmonic polynomials are presented in this article. The polynomials are common eigenfunctions of the square of the angular momentum operator and of the asymmetry distribution Hamiltonian for the rotations of asymmetric molecules, in the body-fixed frame with principal axes. The first set of operators for Lamé polynomials of a given species and a fixed value of the square of the angular momentum raise and lower and lower and raise in complementary ways the quantum numbers $n_1$ and $n_2$ counting the respective nodal elliptical cones. The second set of operators consisting of the cartesian components $hat L_x$, $hat L_y$, $hat L_z$ of the angular momentum connect pairs of the four species of polynomials of a chosen kind and angular momentum. The third set of operators, the cartesian components $hat p_x$, $hat p_y$, $hat p_z$ of the linear momentum, connect pairs of the polynomials differing in one unit in their angular momentum and in their parities. Relationships among spheroconal harmonics at the levels of the three sets of operators are illustrated.

  4. Characterization of topological phases in the compass ladder model

    Haghshenas, R.; Langari, A.; Rezakhani, A. T.

    2016-05-01

    The phase diagram of the quantum compass ladder model is investigated through numerical density matrix renormalization group based on infinite matrix product state algorithm and analytic effective perturbation theory. For this model we obtain two symmetry-protected topological phases, protected by a {{Z}2}× {{Z}2} symmetry, and a topologically-trivial Z 2-symmetry-breaking phase. The symmetry-protected topological phases—labeled by symmetry fractionalization—belong to different topological classes, where the complex-conjugate symmetry uniquely distinguishes them. An important result of this classification is that, as revealed by the nature of the Z 2-symmetry-breaking phase, the associated quantum phase transitions are accompanied by an explicit symmetry breaking, and thus a local-order parameter conclusively identifies the phase diagram of the underlying model. This is in stark contrast to previous studies which require a non-local string order parameter to distinguish the corresponding quantum phase transitions. We numerically examine our results and show that the local-order parameter is related to the magnetization exponent 0.12+/- 0.01 .

  5. Characterization of topological phases in the compass ladder model.

    Haghshenas, R; Langari, A; Rezakhani, A T

    2016-05-01

    The phase diagram of the quantum compass ladder model is investigated through numerical density matrix renormalization group based on infinite matrix product state algorithm and analytic effective perturbation theory. For this model we obtain two symmetry-protected topological phases, protected by a Z2 × Z2 symmetry, and a topologically-trivial Z2-symmetry-breaking phase. The symmetry-protected topological phases--labeled by symmetry fractionalization--belong to different topological classes, where the complex-conjugate symmetry uniquely distinguishes them. An important result of this classification is that, as revealed by the nature of the Z2-symmetry-breaking phase, the associated quantum phase transitions are accompanied by an explicit symmetry breaking, and thus a local-order parameter conclusively identifies the phase diagram of the underlying model. This is in stark contrast to previous studies which require a non-local string order parameter to distinguish the corresponding quantum phase transitions. We numerically examine our results and show that the local-order parameter is related to the magnetization exponent 0.12 ± 0.01. PMID:27023290

  6. Quantum entanglement and thermal reduced density matrices in fermion and spin systems on ladders

    Numerical studies of the reduced density matrix of a gapped spin-1/2 Heisenberg antiferromagnet on a two-leg ladder find that it has the same form as the Gibbs density matrix of a gapless spin-1/2 Heisenberg antiferromagnetic chain at a finite temperature determined by the spin gap of the ladder. We investigate this interesting result by considering a model of free fermions on a two-leg ladder (gapped by the inter-chain tunneling operator) and in spin systems on a ladder with a gapped ground state using exact solutions and several controlled approximations. We calculate the reduced density matrix and the entanglement entropy for a leg of the ladder (i.e. a cut made between the chains). In the fermionic system we find the exact form of the reduced density matrix for one of the chains and determine the entanglement spectrum explicitly. Here we find that in the weak tunneling limit of the ladder the entanglement entropy of one chain of the gapped ladder has a simple and universal form dictated by conformal invariance. In the case of the spin system, we consider the strong coupling limit by using perturbation theory and get the reduced density matrix by the Schmidt decomposition. The entanglement entropies of a general gapped system of two coupled conformal field theories (in 1 + 1 dimensions) are discussed using the replica trick and scaling arguments. We show that (1) for a system with a bulk gap the reduced density matrix has the form of a thermal density matrix, (2) the long-wavelength modes of one subsystem (a chain) of a gapped coupled system are always thermal, (3) the von Neumann entropy equals the thermodynamic entropy of one chain, and (4) the bulk gap plays the role of effective temperature. (paper)

  7. Fish consumption and track to a fish feed formulation

    Cai-Juan, Soong; Ramli, Razamin; Rahman, Rosshairy Abdul

    2015-12-01

    Strategically located in the equator, Malaysia is blessed with plenty of fish supply. The high demand in fish consumption has helped the development in the fishery industry and provided numerous jobs in the secondary sector, contributing significantly to the nation's income. A survey was conducted to understand the trend of current demands for fish for the purpose of designing a feed formulation, which is still limited in this area of study. Results showed that grouper fish in restaurants commanded a very high price compared to other species of fish. Tiger grouper gained the highest demand in most restaurants, while giant grouper had the highest price in restaurants. Due to the demand and challenges to culture this type of fish, a framework for fish feed formulation is proposed. The formulation framework when materialized could be an alternative to the use of trash fish as the feed for grouper.

  8. Duration of pregnancy in relation to fish oil supplementation and habitual fish intake: a randomised clinical trial with fish oil

    Olsen, Sjurdur Frodi; Østerdal, M L; Salvig, J D;

    2007-01-01

    OBJECTIVE: To examine the effect of fish oil supplementation on duration of pregnancy, conditional on the woman's habitual fish intake. DESIGN: Multicentre 1:1 randomised clinical trial of effect of fish oil in a high-risk population of pregnant women in whom habitual fish intake was assessed at ...

  9. Doped spin ladders under magnetic field; Echelles de spins dopees sous champ magnetique

    Roux, G

    2007-07-15

    This thesis deals with the physics of doped two-leg ladders which are a quasi one-dimensional and unconventional superconductor. We particularly focus on the properties under magnetic field. Models for strongly correlated electrons on ladders are studied using exact diagonalization and density-matrix renormalization group (DMRG). Results are also enlightened by using the bosonization technique. Taking into account a ring exchange it highlights the relation between the pairing of holes and the spin gap. Its influence on the dynamics of the magnetic fluctuations is also tackled. Afterwards, these excitations are probed by the magnetic field by coupling it to the spin degree of freedom of the electrons through Zeeman effect. We show the existence of doping-dependent magnetization plateaus and also the presence of an inhomogeneous superconducting phase (FFLO phase) associated with an exceeding of the Pauli limit. When a flux passes through the ladder, the magnetic field couples to the charge degree of freedom of the electrons via orbital effect. The diamagnetic response of the doped ladder probes the commensurate phases of the t-J model at low J/t. Algebraic transverse current fluctuations are also found once the field is turned on. Lastly, we report numerical evidences of a molecular superfluid phase in the 3/2-spin attractive Hubbard model: at a density low enough, bound states of four fermions, called quartets, acquire dominant superfluid fluctuations. The observed competition between the superfluid and density fluctuations is connected to the physics of doped ladders. (author)

  10. Hood River Pelton Ladder Studies : Annual Report 1995.

    Olsen, Erik A.; French, Rod A.; Ritchey, Alan D.

    1996-09-01

    Data collected from this program will provide the baseline information needed to (1) evaluate various management options for implementing the Hood River Production Plan and (2) determine any post-project impacts the Hood River Production Plan has on indigenous populations of resident fish.

  11. Damped Rabi wavepacket oscillations and damping time in correlated random ladders

    Caetano, R. A.; Lyra, M. L.; Schulz, P. A.

    2013-12-01

    In this work, we follow the time evolution of an initially localized one-electron wavepacket in a random ladder model with correlated diagonal disorder. Weak localization of the eigenstates is anticipated for antisymmetric cross-correlations with every base pair having the same average energy. We show that the wavepacket width develops damped Rabi-like oscillations after reaching the ladder's borders. The Rabi-like oscillations are shown to originate from the interference between neighboring energy eigenstates, while its damping is associated with a destructive interference due to the random scattering in the underlying random potential. The typical damping time td is estimated as a function of the ladder size N and shown to increase as td∝Nz with z=0.62(4). The strong localization in the absence of antisymmetric cross-correlations suppresses the oscillations.

  12. Effect of blank holder pressure on viscous pressure forming aluminum alloy ladder parts

    王忠金; 王新云; 王仲仁

    2002-01-01

    Viscous pressure forming (VPF), is suitable for forming difficult-to-form sheet metal parts. An investigation in the effect of blank holder pressure (BHP) on VPF aluminum alloy ladder parts was conducted. Based on experimental and numerical simulation results of the effect of BHP on dimensional accuracy, wall-thickness reduction, forming pressure, material flow and defects (such as wrinkling and fracture) of specimens, the effect patterns of BHP load path on VPF ladder parts were explained. The limits of BHP corresponding to specimens with no defect and with wrinkling or fracture defect were determined. In the limits of formable BHP, the variable load path of BHP was beneficial to drawing blank into the die and decreasing wall-thickness reduction of specimens. The experimental results show that the ladder parts of good surface fineness and high dimensional accuracy can be obtained by variable load paths of BHP.

  13. Dynamic Covalent Assembly of Peptoid-Based Ladder Oligomers by Vernier Templating.

    Wei, Tao; Jung, Jae Hwan; Scott, Timothy F

    2015-12-30

    Dynamic covalent chemistry, in conjunction with template-directed assembly, enables the fabrication of extended nanostructures that are both precise and tough. Here we demonstrate the dynamic covalent assembly of peptoid-based molecular ladders with up to 12 rungs via scandium(III)-catalyzed imine metathesis by employing the principle of Vernier templating, where small precursor units with mismatched numbers of complementary functional groups are coreacted to yield larger structures with sizes determined by the respective precursor functionalities. Owing to their monomer diversity and synthetic accessibility, sequence-specific oligopeptoids bearing dynamic covalent pendant groups were employed as precursors for molecular ladder fabrication. The generated structures were characterized using matrix-assisted laser desorption/ionization mass spectrometry and gel permeation chromatography, confirming successful molecular ladder fabrication. PMID:26639351

  14. Means-end chains and laddering: An inventory of problems and an agenda for research

    Grunert, Klaus G.; Grunert, Suzanne C.; Sørensen, Elin

    about products. Specifically, nonverbal imagery, episodic information, and procedural knowledge are not included in means-end chains. 3. A number of methodological problems can be identified in the collection of means-end chain data. Major problems, which should be addressed in research, are methods to......Executive summary 1. Means-end chains are a device used to understand how consumers mentally link products to self-relevant consequences. Means-end chains are usually measured by a method called laddering. 2. Means-end chains may fall short of tapping all relevant aspects of how consumers think...... elicit the product attributes the laddering is to start with, the integration of a usage situation in the interview, and the basic decision on how much direct the respondent. 4. Concerning the coding of laddering data, a higher degree of transparency of the coding process would be desirable. 5...

  15. 仿生机器鱼胸鳍驱动机构设计%Design of Driving Mechanism of Bionic Robotic Fish Pectoral

    傅继军; 洪梓榕; 殷培峰

    2015-01-01

    设计了一种二自由度的胸鳍驱动机构。该机构采用连杆机构和齿轮机构分别实现仿生机器鱼的前后拍翼运动和摇翼运动,具有运动形式简单、效率高、可靠性好的特点。对驱动机构进行了运动学分析,建立了驱动机构的数学模型。仿生机器鱼通过两侧胸鳍配合,可以实现仿生机器鱼前进、后退、转弯等基本运动,为仿生机器鱼的设计提供了一套切实可行的方案。%This paper proposes a propulsion mechanism for bionic robotic fish with two degrees of freedom pectoral fin.In this design,the lead -lag motion and feathering motion are respectively achieved by linkage mechanism and gear mechanism.The movement characteristics of this mechanism are simple and efficient with good reliability.Its mathematical model is obtained through the analysis of the propulsion mechanism of kinematics.Bionic robotic fish can achieve basic movement such as forward,backward and turn by both sides of the pectoral fins.A feasible solu-tion is provides for the design of a bionic robotic fish.

  16. "Ladder" structure in tonal noise generated by laminar flow around an airfoil.

    Chong, Tze Pei; Joseph, Phillip

    2012-06-01

    The presence of a "ladder" structure in the airfoil tonal noise was discovered in the 1970s, but its mechanism hitherto remains a subject of continual investigation in the research community. Based on the measured noise results and some numerical analysis presented in this letter, the variations of four types of airfoil tonal noise frequencies with the flow velocity were analyzed individually. The ladder structure is proposed to be caused by the acoustic/hydrodynamic frequency lag between the scattering of the boundary layer instability noise and the discrete noise produced by an aeroacoustic feedback loop. PMID:22713022

  17. Delocalization of mechanical waves in the ladder chain of DNA with correlated disorder

    Farzadian, O.; Niry, M. D.

    2016-05-01

    Localization-delocalization transition of mechanical vibrations in a ladder chain with correlated disorder is studied analytically and numerically. An exact analytical analysis is carried out for the delocalization properties of the waves in the ladder chain. This analysis predicts resonance frequencies at which the waves can propagate in the entire chain like DNA. Our analytical results in prediction of extended modes are confirmed by numerical simulations using the transfer matrix method. Finally we consider the entropy of disorder as a control parameter for localization-delocalization transition in chain with correlated disorder.

  18. Magnetic Long-Range Order and Colossal Magnetoresistance Effect in Double Exchange Ladders

    马冬梅; 邹良剑

    2001-01-01

    By applying Bogoliubov's ineguality to double-exchange(DE) ladders, we show that the ferromagnetic(FM) order is absent in the new DE systems at finite temperatures. The incorporation of Jahn-Teller electron-phonon coupling, orbital degeneracy and on-site Coulomb interaction with the DE interaction do not preserve these orders. The long-wavelength thermal fluctuations of the spins oversome the DEFM correlation and destroy the FM orders. The implication of the absence of FM order on the transport of the DE ladders is discussed.

  19. Classical ladder operators, polynomial Poisson algebras, and classification of superintegrable systems

    We recall results concerning one-dimensional classical and quantum systems with ladder operators. We obtain the most general one-dimensional classical systems, respectively, with a third and a fourth-order ladder operators satisfying polynomial Heisenberg algebras. These systems are written in terms of the solutions of quartic and quintic equations. They are the classical equivalent of quantum systems involving the fourth and fifth Painleve transcendents. We use these results to present two new families of superintegrable systems and examples of trajectories that are deformation of Lissajous's figures.

  20. Electric field induced localization phenomena in a ladder network with superlattice configuration: Effect of backbone environment

    Paramita Dutta

    2014-09-01

    Full Text Available Electric field induced localization properties of a tight-binding ladder network in presence of backbone sites are investigated. Based on Green's function formalism we numerically calculate two-terminal transport together with density of states for different arrangements of atomic sites in the ladder and its backbone. Our results lead to a possibility of getting multiple mobility edges which essentially plays a switching action between a completely opaque to fully or partly conducting region upon the variation of system Fermi energy, and thus, support in fabricating mesoscopic or DNA-based switching devices.

  1. Explaining choice option attractiveness by beliefs elicited by the laddering method

    Grunert, Klaus G.; Bech-Larsen, Tino

    2005-01-01

    option. The laddering method is used to elicit beliefs of all three types for a choice between conventional and organic pork. As a benchmark, beliefs were also elicited in the traditional way advocated by Ajzen and Fishbein. Using both sets of beliefs in a subsequent survey, it was shown that the beliefs...... elicited by the laddering method increase explanatory power with regard to choice option attractiveness beyond the beliefs elicited by the Ajzen and Fishbein method, and that this additional explanatory power was due to those beliefs which relate the choice option to concepts with a higher level of...

  2. Climb the Green Ladder Make Your Company and Career More Sustainable

    Fetzer, Amy V

    2009-01-01

    Want to make your workplace more sustainable, get ahead in your career and improve your reputation?. Want to help your company or organisation save money, boost profits and improve its brand?. Whatever your level or industry, from sales and management to government and teaching, Climb The Green Ladder offers practical knowledge to help you make a difference. Whether you'd like to transform your entire company or just get your colleagues recycling, Climb The Green Ladder will provide you with the tools and motivation to move your company (and career) towards a more successful, more sustainable

  3. Number of embeddings of circular and Mbius ladders on surfaces

    2010-01-01

    There are many results on the flexibility of(general) embeddings of graphs,but few are known about that of strong embeddings.In this paper,we study the flexibility of strong embeddings of circular and Mbius ladders on the projective plane and the Klein bottle by using the joint tree model of embeddings.The numbers of(nonequivalent) general embeddings and strong embeddings of circular and Mbius ladders on these two nonorientable surfaces are obtained,respectively.And the structures of those strong embeddings are described.

  4. Universal finite-size corrections of the entanglement entropy of quantum ladders and the entropic area law

    We investigate the finite-size corrections of the entanglement entropy of critical ladders and propose a conjecture for its scaling behaviour. The conjecture is verified for free fermions, for Heisenberg ladders, and for quantum Ising ladders. Our results support that the prefactor of the logarithmic correction of the entanglement entropy of critical ladder models is universal and is associated with the central charge of the one-dimensional version of the models and with the number of branches associated with gapless excitations. Our results suggest that it is possible to infer whether there is a violation of the entropic area law in two-dimensional critical systems by analyzing the scaling behaviour of the entanglement entropy of ladder systems, which are easier to deal with. (paper)

  5. Who cares about fish welfare?

    Ellingsen, Kristian; Grimsrud, Kristine; Nielsen, Hanne Marie;

    2015-01-01

    Purpose – The purpose of this paper is threefold: first, to assess how concerned Norwegians are about fish welfare; second, to investigate Norwegians’ willingness to pay for salmon filet made from welfare-assured farmed fish with high levels of welfare; and third, to examine Norwegian opinions...... about the appropriate way to pay for better welfare standards in fish production. Design/methodology/approach – On the basis of two focus group sessions, a survey questionnaire was developed and distributed to a representative sample of 2,147 Norwegian households via e-mail. Findings – Results showed...... that the Norwegian public is concerned about fish welfare and is willing to pay a price premium for products made from welfare-assured fish. Norwegian consumers do not, however, want to be the only ones paying for fish welfare, as the main responsibility for fish welfare lies with producers and the Government...

  6. Fish health and fish quality

    Ingerslev, Hans-Christian

    Aquaculture is an expanding worldwide industry producing an increasing amount of fish every year. The quality of the fish meat is dependent upon many biological and non-biological factors. Infectious diseases are known to cause bleedings and damage of the muscle tissue that may lead to scarring...... are poorly described in fish. The present work in this thesis focused on: 1) examination of potential changes in the quality regarding texture of the muscle tissue in rainbow trout (Oncorhynchus mykiss) after previous infection with the bacterial pathogens Yersinia ruckeri and Vibrio anguillarum; 2...... of these studies showed that previous infections by Yersinia ruckeri and Vibrio anguillarum gave rise to subsequent changes regarding textural quality parameters in fresh fish meat, while no differences were seen for cold-smoked meat from the same fish. The texture in previous infected fish was less flaky and less...

  7. 基于生态修复的青海湖沙柳河鱼道建设与维护%Construction and management of fish passage on Shaliu River adjacent to Qinghai Lake based on ecological restoration

    吴晓春; 史建全

    2014-01-01

    Gymnocypris przewalskii belongs to subfamily of Schizothoracinae, family of Cyprinidae and order of Cypriniformes, and it is an endemic species only distributed in the Qinghai Lake and its adjacent rivers and lakes. It possesses migration characteristics, and goes upstream from the lake to surrounding rivers in the reproduction season. However, several dams built on the rivers flowing into the lake with the agricultural development in the Qinghai Lake region since 1970s, severely blocked its migration passages, leading to obviously decreasing of resources of Gymnocypris przewalskii in recent years. To protect Gymnocypris przewalskii, three kinds of fish passages on the dams of rivers flowing into the Qinghai Lake were introduced, which were types of guide wall, simple steel modular and ladder slope, respectively. 1) The guide wall type fish passage was separately constructed on the dams in the Shaliu River, Quanji River and Haergai River in 2006, which were built along river side, but it had several defects because of the lack of experience. 2) The simple steel modular type fish passage was designed and constructed on the dam of the Shaliu River in 2008, Based on biological characteristics of Gymnocypris przewalskii and the basic situation of the dam and environmental conditions of the Shaliu River. After considering inlet location of fish passage, suction flow and hydraulic conditions within passage, the inlet was located at the area with aggregated fish and slow current velocity. The water flow was 0.5 m/s, the current velocity was 0.1-0.25 m3/s, as well as the slope of 1:10 within fish passage. 3) The ladder slope type fish passage was built on the dam of Shaliu River in 2010, which used two types open fishponds of multi-ladder and slight slope. Fish passage without hindrance had been almost come to be real through this type. This type was designed according to basic theories and related parameters of simple fish passage. The length was 80 m and the width was 1

  8. Measuring subjective meaning structures by the laddering method: Theoretical considerations and methodological problems

    Grunert, Klaus G.; Grunert, Suzanne C.

    1995-01-01

    Starting from a general model of measuring cognitive structures for predicting consumer behaviour, we discuss laddering as a possible method to obtain estimates of consumption-relevant cognitive structures which will have predictive validity. Four criteria for valid measurement are derived and ap...

  9. Avionics Instrument Systems Specialist Career Ladder: AFSCs 32531, 32551, 31571, and 32591. Occupational Survey Report.

    Air Force Occupational Measurement Center, Lackland AFB, TX.

    The Avionics Instrument Systems career ladder (AFSC 325X1) provides flight line and shop maintenance training on aircraft instrument systems, electromechancial instruments, components, and test equipment. Duties involve inspecting, removing, installing, repairing, operating, troubleshooting, overhauling, and modifying systems such as flight and…

  10. Means-end chains and laddering: An inventory of problems and an agenda for research

    Grunert, Klaus G.; Beckmann, Suzanne C.; Sørensen, Elin

    2001-01-01

    Laddering and means-end chains are one of the most promising developments in consumer research since the 1980s. It is an approach that takes consumers' individuality seriously but, nevertheless, comes up with quantitative results. It is rooted in a cognitive approach, and allows for emotional and...

  11. Online measurement of mental representations of complex spatial decision problems : Comparison of CNET and hard laddering

    O. Horeni (Oliver); T.A. Arentze (Theo); B.G.C. Dellaert (Benedict); H.J.P. Timmermans (Harry)

    2013-01-01

    textabstractThis paper introduces the online Causal Network Elicitation Technique (CNET), as a technique for measuring components of mental representations of choice tasks and compares it with the more common technique of online ‘hard’ laddering (HL). While CNET works in basically two phases, one in

  12. Studies of quantum spin ladders at T = 0 and at high temperatures

    Compounds have recently been found which, to a first approximation, can be regarded as 'spin ladders', i.e. 2 or 3 coupled chains of S = 2 ions. These are (VO)2P2O7 and SrCu2O3 (2 chains), and SrCu3O5 (3 chains). A number of striking theoretical predictions have been made for such systems. Ladders with an even number of legs have an energy gap, short range correlations and a 'spin liquid' ground state. Ladders with an odd number of legs, on the other hand, have gapless excitations and quasi long range order. Experiments appear to confirm these features, which are analogous to the Haldane gap in integer chains. We have carried out extensive series studies of 2-chain and 3-chain ladder systems, both at T = 0 and at high temperatures. Our results confirm the existence of a gap in the 2-chain system and identify the structure of the phase diagram. The dispersion law for excitations is estimated. For the 3-chain system we are unable to exclude the possibility of a small gap, although our results are quite consistent with a gapless spectrum. We estimate the high temperature magnetic susceptibility and compare with previous calculations and with experiment

  13. Climbing the "Agricultural Ladder": Social Mobility and Motivations for Migration in an Ecuadorian Colonist Community

    Bates, Diane C.; Rudel, Thomas K.

    2004-01-01

    During the early decades of the 20th century in the American Midwest young farming families achieved social mobility by moving up an 'agricultural ladder' through a series of rungs, from unpaid family work, to wage labor, to tenant farming, to a mortgaged farm, and, finally, to full ownership of a farm. In this paper we use the concept of an…

  14. On the Orchard crossing number of prisms, ladders and other related graphs

    Feder, Elie

    2011-01-01

    This paper deals with the Orchard crossing number of some families of graphs which are based on cycles. These include disjoint cycles, cycles which share a vertex and cycles which share an edge. Specifically, we focus on the prism and ladder graphs.

  15. Texture Fish

    Stone, Julie

    2007-01-01

    In an effort to provide an opportunity for her first graders to explore texture through an engaging subject, the author developed a three-part lesson that features fish in a mixed-media artwork: (1) Exploring Textured Paint; (2) Creating the Fish; and (3) Role Playing. In this lesson, students effectively explore texture through painting, drawing,…

  16. Fish parasites

    This book contains 22 chapters on some of the most important parasitic diseases in wild and farmed fish. International experts give updated reviews and provide solutions to the problems......This book contains 22 chapters on some of the most important parasitic diseases in wild and farmed fish. International experts give updated reviews and provide solutions to the problems...

  17. Benefits of fish passage and protection measures at hydroelectric projects

    The US Department of Energy's Hydropower Program is engaged in a multi-year study of the costs and benefits of environmental mitigation measures at nonfederal hydroelectric power plants. An initial report (Volume 1) reviewed and surveyed the status of mitigation methods for fish passage, instream flows, and water quality; this paper focuses on the fish passage/protection aspects of the study. Fish ladders were found to be the most common means of passing fish upstream; elevators/lifts were less common, but their use appears to be increasing. A variety of mitigative measures is employed to prevent fish from being drawn into turbine intakes, including spill flows, narrow-mesh intake screens, angled bar racks, and lightor sound-based guidance measures. Performance monitoring and detailed, quantifiable performance criteria were frequently lacking at non-federal hydroelectric projects. Volume 2 considers the benefits and costs of fish passage and protection measures, as illustrated by case studies for which performance monitoring has been conducted. The report estimates the effectiveness of particular measures, the consequent impacts on the fish populations that are being maintained or restored, and the resulting use and non-use values of the maintained or restored fish populations

  18. Effective models of doped quantum ladders of non-Abelian anyons

    Soni, Medha; Troyer, Matthias; Poilblanc, Didier

    2016-01-01

    Quantum spin models have been studied extensively in one and higher dimensions. Furthermore, these systems have been doped with holes to study t -J models of SU (2 ) spin-1/2. Their anyonic counterparts can be built from non-Abelian anyons, such as Fibonacci anyons described by SU (2) 3 theories, which are quantum deformations of the SU (2 ) algebra. Inspired by the physics of SU (2 ) spins, several works have explored ladders of Fibonacci anyons and also one-dimensional (1D) t -J models. Here, we aim to explore the combined effects of extended dimensionality and doping by studying ladders composed of coupled chains of interacting itinerant Fibonacci anyons. We show analytically that in the limit of strong rung couplings these models can be mapped onto effective 1D models. These effective models can either be gapped models of hole pairs, or gapless models described by t -J (or modified t -J -V ) chains of Fibonacci anyons, whose spectrum exhibits a fractionalization into charge and anyon degrees of freedom. The charge degrees of freedom are described by the hardcore boson spectra while the anyon sector is given by a chain of localized interacting anyons. By using exact diagonalizations for two-leg and three-leg ladders, we show that indeed the doped ladders show exactly the same behavior as that of t -J chains. In the strong ferromagnetic rung limit, we can obtain a new model that hosts two different kinds of Fibonacci particles, which we denote as the heavy τ 's and light τ 's. These two particle types carry the same (non-Abelian) topological charge but different (Abelian) electric charges. Once again, we map the two-dimensional ladder onto an effective chain carrying these heavy and light τ 's. We perform a finite size scaling analysis to show the appearance of gapless modes for certain anyon densities, whereas a topological gapped phase is suggested for another density regime.

  19. The tunable quantum spin ladder Cu(Qnx)(Cl{sub (1−x)}Br{sub x}){sub 2}

    Povarov, K.Yu., E-mail: povarovk@phys.ethz.ch [Neutron Scattering and Magnetism, Laboratory for Solid State Physics, ETH Zürich (Switzerland); Lorenz, W.E.A. [Neutron Scattering and Magnetism, Laboratory for Solid State Physics, ETH Zürich (Switzerland); Xiao, F.; Landee, C.P. [Department of Physics, Clark University, Worcester, MA 01610 (United States); Krasnikova, Y. [P.L. Kapitza Institute for Physical Problems RAS, 119334, Moscow (Russian Federation); Moscow Institute for Physics and Technology, 141700 Dolgoprudny (Russian Federation); Zheludev, A. [Neutron Scattering and Magnetism, Laboratory for Solid State Physics, ETH Zürich (Switzerland)

    2014-12-15

    We report magnetic, specific heat and ESR measurements on a series of S=1/2 spin ladder compounds Cu(Qnx)(Cl{sub (1−x)}Br{sub x}){sub 2}. Down to T=2 K all the observables can be described by the spin ladder model with about 1% of S=1/2 impurities in the background, which are present even in a nominally pure Cu(Qnx)Cl{sub 2} and Cu(Qnx)Br{sub 2}, for the whole range of 0≤x≤1. We extract ladder exchange constants J{sub l}(x) and J{sub r}(x) as well as the gap value Δ(x) by comparing the experimental data to quantum Monte-Carlo simulations. As the ESR measurements show the g-factor of impurities to be precisely equal to g-factor of the ladder spins, we suppose the impurities to be the consequence of structural defects resulting in broken ladder ends. - Highlights: • A family of isostructural spin-ladder compounds was investigated. • A variation in exchange parameters with the degree of chemical substitution was found. • A small amount of paramagnetic spins was attributed to structural defects in a ladder.

  20. Reynolds shear-stress and velocity: positive biological response of neotropical fishes to hydraulic parameters in a vertical slot fishway

    Bernardo Alan de Freitas Duarte

    2012-10-01

    Full Text Available The barriers created by dams can cause negative impacts to aquatic communities, and migratory fish species are directly affected. Fishways have been developed to allow the upstream passage of fishes through dams. In Brazil, after the implementation of environmental laws, these structures have been built based on European and American fishway designs. Studies have shown selectivity for different neotropical fishes in some Brazilian fishways, and the main challenge has been to promote upstream passage of a large number of diverse fish species. The patterns of flow circulation within the fish ladder may explain fish selectivity although few studies detail the fish response to hydraulic characteristics of fish ladder flow. This paper presents a laboratory study, where a vertical slot fishway was built in a hydraulic flume and the behavior of two neotropical fish species (Leporinus reinhardti and Pimelodus maculatus were analyzed. The structure of flow was expressed in terms of mean velocity, Reynolds shear-stress and velocity fluctuation fields. The individuals of Leporinus reinhardti had higher passage success than Pimelodus maculatus in the laboratory flume. Both species preferred areas of low to zero Reynolds shear-stress values. In addition, different preferences were observed for these species concerning the horizontal components of velocity fluctuation.Interrupções em rios, como as causadas por barragens, provocam impactos negativos sobre as comunidades aquáticas e as espécies migratórias de peixes são diretamente afetadas. A fim de permitir a passagem de peixes, mecanismos de transposição são construídos junto a barramentos. No Brasil, após a implantação de leis ambientais, estas estruturas passaram a ser amplamente construídas e foram baseadas em projetos desenvolvidos na Europa e na América do Norte. Análises de mecanismos já construídos têm mostrado grande seletividade para espécies neotropicais e as demandas da diversa

  1. Design of Heat Pipe Type Adsorption Ice Maker for Fishing Boats%热管型船用吸附制冰机的设计

    王丽伟; 王如竹; 夏再忠; 吴静怡

    2005-01-01

    A heat pipe type adsorption ice maker with two adsorbers for fishing boats is designed by using ammonia as refrigerant and compound of activated carbon-CaCl2 as adsorbent. This type of heat pipe adsorber can solve the problem of incompatibility between ammonia, copper, seawater and steel. The working process of the ice maker with 8.7kg adsorbent per bed is simulated. The results show that the optimal semi-cycle time is about 9min at the evaporating temperature of -15℃, where the corresponding cooling power, specific cooling power per kilogram adsorbent SCP and coefficient of refrigerant performance COP are respectively 3.6 kW, 217W·kg-1 and 0.404.

  2. Pallet insertion glovebox/hood control ladder diagram. Final project report

    The pallet insertion glovebox/hood (G/H) is a special confinement space that will be designed to allow for insertion of pallets into the Stacker/Retriever (S/R) area. The S/R a large vault that is kept at negative 1 inches w.c. relative to the atmosphere and is used for the safe storage of special nuclear material. The S/R system uses a vehicle to move the special nuclear material that are placed on the pallets from the storage bins to input/output (I/O) stations and vice versa. As the name suggest the I/O stations are used to place the material into the S/R vault or to remove material from the S/R vault. The pallets are specially designed structures that will hold certain numbers of the material containers in a safe configuration. To store additional material containers, there is a need to insert additional pallets in the SIR vault. Due to the presence of radioactive contamination and the fact that the vault must be kept at a negative pressure at all times, one of the several I/O stations will be modified so that pallets could be inserted into the S/R vault. The ventilation system for the S/R area is a dedicated system that recirculates nitrogen with less than 5% oxygen by volume throughout the area while exhausting small option of the nitrogen to keep the S/R at negative 1 inches w.c. relative to the atmosphere. The rooms surrounding the G/H and the S/R area are maintained at negative of 0.3 inches w.c. relative to the outside atmosphere. Both the G/H and the control system for the G/H will be designed such that the confinement requirements of the S/R and the G/H system will not be jeopardized. A ladder diagram will be developed to illustrate the control system

  3. Mathematical model analysis on the enhancement of aeration efficiency using ladder-type flat membrane module forms in the Submerged Membrane Bio-reactor(SMBR)

    2009-01-01

    The cross-flow shearing action produced from the inferior aeration in the Submerged Membrane Bio-reactor(SMBR) is an effective way to further improve anti-fouling effects of membrane modules.Based on the widely-applied vertical structure of flat membrane modules,improvements are made that ladder-type flat membrane structure is designed with a certain inclined angle θ so that the cross-flow velocity of bubble near the membrane surface can be held,and the intensity and times of elastic colli-sion between bubbles and membrane surface can be increased.This can improve scouring action of membrane surface on aeration and reduce energy consumption of strong aeration in SMBR.By de-ducing and improving the mathematics model of collision between bubble and vertical flat put forward by Vries,the relatively suitable incline angle θ under certain aeration place and in certain size rang of bubble can be obtained with the computer iterative calculation technology.Finally,for many groups of ladder-type flat membrane in parallel placement in the practical application of SMBR,some sugges-tions are offered:the interval distance of membrane modules is 8―15 mm,and aeration should be op-erated at 5―7 mm among membrane modules,and the optimal design angle of trapeziform membrane is 1.7°―2.5°.

  4. Mathematical model analysis on the enhancement of aeration efficiency using ladder-type flat membrane module forms in the Submerged Membrane Bio-reactor (SMBR)

    LI Bo; YE MaoSheng; YANG FengLin; MA Hui

    2009-01-01

    The cross-flow shearing action produced from the inferior aeration in the Submerged Membrane Bio-reactor (SMBR) Is an effective way to further improve anti-fouling effects of membrane modules.Based on the widely-applied vertical structure of flat membrane modules, improvements are made that ladder-type flat membrane structure is designed with a certain inclined angle θ so that the cross-flow velocity of bubble near the membrane surface can be held, and the intensity and times of elastic colli-sion between bubbles and membrane surface can be increased. This can improve scouring action ofmembrane surface on aeration and reduce energy consumption of strong aeration in SMBR. By de-ducing and improving the mathematics model of collision between bubble and vertical flat put forward by Vries, the relatively suitable Incline angle θ under certain aeration place and in certain size rang ofbubble can be obtained with the computer iterative calculation technology. Finally, for many groups of ladder-type flat membrane in parallel placement in the practical application of SMBR, some sugges-tions are offered: the interval distance of membrane modules is 8--15 mm, and aeration should be op-erated at 5--7 mm among membrane modules, and the optimal design angle of trapeziform membrane is 1.7°--2.5°.

  5. One Fish, Two Fish, Redfish, You Fish!

    White, Katherine; Timmons, Maryellen; Medders, Paul

    2011-01-01

    The recreational fishing activity presented in this article provides a hands-on, problem-based experience for students; it unites biology, math, economics, environmental policy, and population dynamics concepts. In addition, the activity allows students to shape environmental policy in a realistic setting and evaluate their peers' work. By…

  6. Evaluation of Juvenile Fish Bypass and Adult Fish Passage Facilities at Water Diversions on the Umatilla River; 1994 Annual Report.

    Knapp, Suzanne M.

    1995-01-01

    We report on our progress from October 1993 through September 1994 in evaluating juvenile salmonid bypass facilities and juvenile salmonid passage through ladder facilities, and investigating passage conditions for juvenile fish at diversion dam facilities on the lower Umatilla River in northeastern Oregon. We also report on our progress in evaluating adult salmonid passage at and between dams on the lower Umatilla River and upriver migration using radio telemetry. Two principal studies are also included. Report A (ODFW): To evaluate the juvenile salmonid bypass facilities a Feed and Furnish canals, juvenile salmonid passage through fish ladders at Stanfield, Feed Canal, Westland, and Three Mile Falls dams, and the juvenile salmonid trap and haul procedures at Westland Canal. To investigate passage conditions at all passage facilities. Report B (CTUIR): To examine the passage of adult salmonids past diversions in the lower Umatilla River and their movement in the upper river after transport, using radio telemetry, and to assess factors for successful homing. These studies are part of a program to rehabilitate anadromous fish stocks in the Umatilla River Basin, including restoration of coho salmon (Oncorhynchus kisutch) and chinook salmon (Oncorhynchus tshawytscha), as well as enhancement of summer steelhead (Oncorhynchus mykiss).

  7. Learning from Fish: Kinematics and Experimental Hydrodynamics for Roboticists

    George V. Lauder; Peter G. A. Madden

    2006-01-01

    Over the past 20 years, experimental analyses of the biomechanics of locomotion in fishes have generated a number of key findings that are relevant to the construction of biomimetic fish robots. In this paper, we present 16 results from recent experimental research on the mechanics, kinematics, fluid dynamics, and control of fish locomotion that summarize recent work on fish biomechanics. The findings and principles that have emerged from biomechanical studies of fish locomotion provide important insights into the functional design of fishes and suggest specific design features relevant to construction of robotic fish-inspired vehicles that underlie the high locomotor performance exhibited by fishes.

  8. H-Bonding Self-assembled Template-directed Synthesis of a Reactive Amide-bridged Ladder Polyvinylsiloxane

    You Zhi WAN; Ying Hua LIU; Ping XIE; Rong Ben ZHANG

    2006-01-01

    A novel, reactive amide-bridged ladder polyvinylsiloxane (abbr. LP) with Mn = 2.4×104was synthesized for the first time by means of aryl amide H-bonding self-assembled template.The regularity of LP was characterized by the XRD, 29Si NMR and DSC methods. XRD analysis demonstrated the ladder width w = 9.09 A and the ladder thickness t = 3.89 A, respectively, which are approximately consistent with the molecular simulation-calculated ones: w'= 10.60 A and t'=3.06 A. 29Si NMR displayed a resonance peak with small half peak width, △1/2 ~ 4 ppm, for the moiety [=Si(Vi)O2/2-]n of LP. Besides, as a collateral evidence, DSC measurement revealed a high glass transition temperature Tg = 225℃, suggesting high stiffness of the ladder main chain of LP.

  9. Implementation of Evidence-Based Practice in Relation to a Clinical Nursing Ladder System: A National Survey in Taiwan

    Weng, Yi-Hao; Chen, Chiehfeng; Kuo, Ken N.; Yang, Chun-Yuh; Lo, Heng-Lien; Chen, Kee-Hsin; Chiu, Ya-Wen

    2015-01-01

    Background Although evidence-based practice (EBP) has been widely investigated, few studies have investigated its correlation with a clinical nursing ladder system. The current national study evaluates whether EBP implementation has been incorporated into the clinical ladder system. Methods A cross-sectional questionnaire survey was conducted nationwide of registered nurses among regional hospitals of Taiwan in January to April 2011. Subjects were categorized into beginning nurses (N1 and N2)...

  10. Alabama ESI: FISH (Fish Polygons)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine, estuarine, and freshwater fish species in Alabama. Vector polygons in this data set represent...

  11. Maryland ESI: FISH (Fish Polygons)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine, estuarine, anadromous, and freshwater fish species in Maryland. Vector polygons in this data...

  12. Hawaii ESI: FISH (Fish Polygons)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for reef, marine, estuarine, and native stream fish species in coastal Hawaii. Vector polygons in this...

  13. Virginia ESI: FISH (Fish Polygons)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine, estuarine, anadromous, and brackishwater fish species in Virginia. Vector polygons in this...

  14. Louisiana ESI: FISH (Fish Polygons)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for freshwater (inland) fish species in coastal Louisiana. Vector polygons represent water-bodies and...

  15. A simple and practical method that prepares high molecular weight DNA ladders.

    Zhang, Jun-He; Yang, Rui; Wang, Tian-Yun; Dong, Wei-Hua; Wang, Fang; Wang, Li

    2012-11-01

    The purpose of the current study was to report a simple and practical method to prepare high molecular weight (mw) DNA ladders. The method involves 1,000-4,000-base pairs (bp) DNA fragments being amplified by polymerase chain reaction (PCR), using λ DNA as a template. The constructed plasmids are digested by restriction endonucleases to produce 5-, 6-, 8- and 10-kb DNA fragments, followed by purification and precipitation with ethanol, and mixed proportionally. The 1,000-4,000-bp DNA fragments were successfully generated by PCR and 5-, 6-, 8- and 10-kb DNA fragments were obtained through the digestion of the plasmids. The bands of the prepared high mw DNA ladder were clear and may aid future molecular biology studies. PMID:22948498

  16. Hopping ladder and power relaxation due to donor-acceptor pairs

    Hopping between donor-acceptor pairs leads to peculiar temperature dependence of the conductivity and the photoconductivity under subband gap illumination in the form of non-linear activation energies ladder. The correlated and uncorrelated distributions of pairs are considered and the conditions for the ladder existence are determined. The relaxation of the carrier concentration fluctuations is studied and power type decay is found. The temperature dependence of the exponent is calculated in agreement with the non-exponential decay of the pulse excited luminescence observed by Dean et al. The temperature dependence of the luminescence intensity also shows variable activation energy as found here. The exponent value α=1.316 is also in agreement with the data for crystalline and amorphous materials. (author)

  17. Fishing amplifies forage fish population collapses

    Essington, Timothy E.; Moriarty, Pamela E.; Froehlich, Halley E.; Hodgson, Emma E.; Koehn, Laura E.; Oken, Kiva L.; Siple, Margaret C.; Stawitz, Christine C.

    2015-01-01

    Forage fish provide substantial benefits to both humans and ocean food webs, but these benefits may be in conflict unless there are effective policies governing human activities, such as fishing. Collapses of forage fish induce widespread ecological effects on dependent predators, but attributing collapses to fishing has been difficult because of natural fluctuations of these stocks. We implicate fishing in forage fish stock collapses by showing that high fishing rates are maintained when sto...

  18. H-bonding template-directed synthesis of a complete m-PDA-bridged ladder polyhydrosiloxane (OLPHS)

    2007-01-01

    A highly ordered m-phenylenediimino-bridged ladder polyhydrosiloxane (abbr. OLPHS) with Mn = 1.24 × 104 was synthesized stoichiometric hydrolysis and dehydrochlorination condensation reaction between Si-Cl and Si-OH bonds. The complete ladder structure of OLPHS has been confirmed by the following three data. Two characteristic Bragg's peaks representing the ladder width (w = 0.94 nm) and ladder thickness (t = 0.42 nm) were observed in XRD analysis, which are consistent with those calculated by molecular simulation. The very sharp absorption with a small half-peak width (w1/2 = 0.5 ppm) for [(-HN)HSiO2/2]n moiety of OLPHS in 29Si NMR spectrum indicated presence of the complete ladder structure. As collateral evidence, a higher glass transition temperature (Tg = 105 ℃) is also recorded in the DSC measurement, implying the high stiffness of ladder chain of OLPHS.(C) 2007 Rong Ben Zhang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

  19. A Study of Regional Brand Positioning Strategy for Linhai Orange Based on Soft Laddering

    Tao, Ying; Zhang, Yueli

    2015-01-01

    In this paper, Means-End Chain Theory is used for the positioning strategy study on regional brand of Linhai Orange, and based on soft laddering method, 33 Linhai Orange consumers are interviewed. By understanding the individual needs of Linhai Orange consumers, this paper establishes the "Attributes- Consequences-Value" matrix and hierarchical value map. This study aims to explore the regional brand positioning strategy of Linhai Orange, in order to promote the regional brand building and ex...

  20. Specific heat spectra of non-interacting fermions in a quasiperiodic ladder sequence

    We compute the specific heat spectra of non-interacting fermions whose energy spectrum was obtained from a quasiperiodic ladder sequence (Fibonacci and Rudin-Shapiro type), mimicking a DNA molecule model. The specific heat is calculated from their underlying multi-fractal energy spectrum, considering several values of energy densities. Comparisons are made with a real DNA sequence, namely the human chromosome 22 (Ch22)

  1. Ladder operators and associated algebra for position-dependent effective mass systems

    Amir, Naila; Iqbal, Shahid

    2015-07-01

    An algebraic treatment of shape-invariant quantum-mechanical position-dependent effective mass systems is discussed. Using shape invariance, a general recipe for construction of ladder operators and associated algebraic structure of the pertaining system, is obtained. These operators are used to find exact solutions of general one-dimensional systems with spatially varying mass. We apply our formalism to specific translationally shape-invariant potentials having position-dependent effective mass.

  2. Czech Managerial Compensations: Why Does It Pay Off to Climb the Corporate Ladder?

    Teodora Paligorova

    2005-01-01

    This paper uses matched employer-employee data for the Czech Republic to study the structure of managerial compensation. The evidence supports two key predictions from tournament theory. First, the managerial pay differential between organizational levels is non-decreasing as one goes up the corporate ladder. I document a particularly large increment of the pay differential at the top of a firm's hierarchy. Second, the winner's prize in the tournament increases with the number of competitors ...

  3. Analysis of an integral equation for causal distributions in the ladder PHI63 theory

    Using the integral equation for a spectral function, the behaviour of the spectral function of the Deser-Gilbert-Sudarshan representation for matrix elements of the current commutator in the ladder approximation for the PHI63 field theory is studied. The integral equation for a spectral function is formulated and solved. The solution for the spectral function does not satisfy the necessary condition of automodelity. The current commutator behaviour near the light cone is derived

  4. An assessment of the motivational impacts of a career ladder/merit pay pilot program

    McNeil, Otis

    1987-01-01

    The purposes of this descriptive investigation were (l) to construct a reliable instrument for assessing attitudes toward teaching of high school teachers, and (2) to determine if there was a difference in attitudes toward teaching between those high school teachers who were and those who were not involved in a career ladder/merit pay pilot program. Frederick Herzberg's Motivation-Hygiene Theory served as the theoretical basis for the investigation. Analysis of work moti...

  5. Magneto-optical polarization rotation in a ladder-type atomic system for tunable offset locking

    Parniak, Michał; Leszczyński, Adam; Wasilewski, Wojciech

    2016-04-01

    We demonstrate an easily tunable locking scheme for stabilizing frequency-sum of two lasers on a two-photon ladder transition based on polarization rotation in warm rubidium vapors induced by magnetic field and circularly polarized drive field. Unprecedented tunability of the two-photon offset frequency is due to strong splitting and shifting of magnetic states in external field. In our experimental setup, we achieve two-photon detuning of up to 700 MHz.

  6. Variation of the absorption and dispersion profiles in a ladder-four-level system

    Li Yong-Fang; Sun Jian-Feng; Niu Yue-Ping

    2004-01-01

    A theoretical research on the variation of the absorption and dispersion profiles and population distribution of each level in a ladder-four-level system driven by two coherent fields has been made. Whether the variation occurs or not depends on the effect of quantum interference, the detuning of the upper coherent field and the separation of the two intermediate levels. A dressed-state analysis is introduced to explain the numerical results.

  7. “Why Caipirinha?”- The Online via Chat Laddering Technique CAN Answer

    Bruno Bordeaux-Rego

    2011-04-01

    Full Text Available As customers are becoming increasingly connected to the internet, this means that they are available for online interviews, thus opening up a space for investigating research methods, especially qualitative research, in an attempt to identify how to adapt data collecting instruments to the so-called “connected customer era”. In this context, the focus of this article is on the application viability analysis of the laddering technique used online and in real-time chat by asking the following question: “Why caipirinha?”. Conducting online in-depth interviews through the MSN Messenger and Skype (the most commonly used chat tools in Brazil, 23 attributes, 22 consequences and 13 values were identified, resulting in 133 ladders, 71 of which reached the value level. Along with friends/mates, Integration, Entertainment and Fun, in addition to Alcohol, Insouciance/ relaxation and Pleasure constitute the most frequent ladders. Concerning the application itself, the participants gave positive feedback, even though some of them did not feel satisfied because they became tired. Convenience, objectivity, disinhibition, easy scheduling and flexibility were identified. The viability of online in-depth interviewing via real-time chats was confirmed, raising the question of the possibility of it achieving other qualitative research techniques.

  8. A clinical ladder program based on Carper's Fundamental Patterns of Knowing in Nursing.

    Schmidt, Lee A; Nelson, Deana; Godfrey, Leah

    2003-03-01

    Clinical and career ladder programs were popular adjuncts to recruitment and retention during the nursing shortage of the 1980s. Programs commonly used Benner's work as an organizing framework and typically used activities such as continuing education credit, committee participation, work experience, certifications, academic degrees, community service, and performance appraisal scores as criteria for advancement. The authors present a unique clinical ladder program based on Carper's Fundamental Patterns of Knowing in Nursing. This philosophical work has been debated in the literature for many years, yet to the authors' knowledge, this work has never been used as the conceptual basis for program development. The four patterns of knowing in nursing were found to be consistent with the definition of professional nursing, and provided a meaningful organizing framework that was well received by staff registered nurses. An overall history of clinical ladders is presented, followed by the organization's prior experience with these programs, and finally the details of development and implementation of the program with plans for evaluation. PMID:12629301

  9. Alkylphenols, Other Endocrine-Active Chemicals, and Fish Responses in Three Streams in Minnesota - Study Design and Data, February-September 2007

    Lee, Kathy E.; Schoenfuss, Heiko L.; Jahns, Nathan D.; Brown, Greg K.; Barber, Larry B.

    2008-01-01

    This report presents the study design and environmental data for an integrated chemical and biological study of three streams (South Fork Crow River, Redwood River, and Grindstone River) that receive wastewater in Minnesota. The objective of the study was to identify distribution patterns of endocrine-active chemicals and other organic chemicals indicative of wastewater, and to identify fish responses in the same streams. Endocrine-active chemicals are a class of chemicals that interfere with the natural regulation of endocrine systems, and an understanding of their distribution in aquatic systems is important so that aquatic organism exposure can be evaluated. This study was a cooperative effort of the U.S. Geological Survey (USGS), the Minnesota Pollution Control Agency, and St. Cloud State University (St. Cloud, Minn.). The USGS collected and analyzed water and quality-assurance samples and measured streamflow during six sampling events in each of three streams. Water samples were collected upstream from and at two successive points downstream from wastewater-treatment plant (WWTP) effluent discharge and from treated effluent from February through September 2007. Bed-sediment samples were collected during one sampling period at each of the stream locations. Water and bed-sediment samples were analyzed for endocrine-active chemicals including alkylphenols, alkylphenol polyethoxylates, and nonylphenol ethoxycarboxlylates (NPECs). Water samples also were analyzed for major ions, nutrients, and organic carbon. In addition, as part of an intensive time-series investigation, the USGS staff collected daily water samples for 8 weeks from the Redwood River near Marshall, Minn., for analyses of total alkylphenols and atrazine. St. Cloud State University staff collected and analyzed fish to determine male fish responses at all water sampling sites and at an additional site near the discharge of wastewater-treatment plant effluent to these streams. Male fish responses

  10. Constructing a fish metabolic network model

    Li, S.; Pozhitkov, A.; R. Ryan; Manning, C; Brown-Peterson, N.; Brouwer, M

    2010-01-01

    We report the construction of a genome-wide fish metabolic network model, MetaFishNet, and its application to analyzing high throughput gene expression data. This model is a stepping stone to broader applications of fish systems biology, for example by guiding study design through comparison with human metabolism and the integration of multiple data types. MetaFishNet resources, including a pathway enrichment analysis tool, are accessible at http://metafishnet.appspot.com.

  11. 基于改进蚁群算法的梯式轨道多目标优化研究%Multi-objective optimization for ladder track based on improved ant colony algorithm

    金浩; 刘维宁

    2014-01-01

    鉴于梯式轨道在实际应用过程中,需要同时优化钢轨振动加速度和道床振动加速度,利用MO-FHACO(多目标觅食-返巢机制连续域蚁群算法)对其进行双目标优化。利用四端参数法建立对应的梯式轨道数学模型,将1~80 Hz频段钢轨振动加速度级和道床振动加速度级作为优化目标,枕下减振垫刚度和数量作为设计变量。经过MO-FHACO双目标优化,成功得到梯式轨道双目标优化解。结果表明,采用MO-FHACO对梯式轨道进行多目标优化具有工程应用价值。%In order to optimize rail vibration acceleration and foundation vibration acceleration for the ladder track, MO-FHACO(multi-objective foraging-homing ant colony algorithm)is employed in this paper. The ladder track is sim-plified using four-pole parameter method. Vibration acceleration level of rail and vibration acceleration level of foundation ranging from 1 Hz to 80 Hz are set objective functions. Stiffness and number of sleeper bearings are set designing variables. After several optimizations by MO-FHACO, optimization solutions of bi-objective for the ladder track are obtained. Results show that, it’s an efficient method for multi-objective optimization of the ladder track with MO-FHACO.

  12. First-order commensurate-incommensurate magnetic phase transition in the coupled FM spin-1/2 two-leg ladders

    Jahangiri, J; Mahdavifar, S; Shayesteh, S Farjami

    2015-01-01

    We consider the spin-1/2 two-leg ladders with ferromagnetic (FM) interactions along legs and rungs. Using the stochastic series expansion QMC method, we study the low-temperature magnetic behavior of the system. An isolated spin-1/2 FM two-leg ladder is in the gapped saturated FM phase at zero temperature. As soon as the spin-1/2 FM two-leg ladders are connected with antiferromagnetic (AFM) inter-ladder interaction, a first-order commensurate-incommensurate quantum phase transition occurs in the ground state magnetic phase diagram. In fact a jump in the magnetization curve is observed. We found that, coupled spin-1/2 FM two-leg ladders are in a nonmagnetic phase at zero temperature. Applying a magnetic field, the ground state of coupled spin-1/2 FM two-leg ladders remains in the nonmagnetic phase up to a quantum saturate critical field.

  13. Status of fish passage facilities at nonfederal hydropower projects

    The status of direct mitigation practices for fish passage was assessed as part of an ongoing, multi-year study of the costs and benefits of environmental mitigation measures at nonfederal hydroelectric power plants. Information was obtained from the Federal Energy Regulatory Commission, hydropower developers and state and federal resource agencies involved in hydropower regulation. Fish ladders were found to be the most common means of passing fish upstream; elevators/lifts were less common, but their use appears to be increasing. A wide variety of mitigative measures, including spill flows, narrow-mesh intake screens, angled bar racks and light- or sound-based guidance measures, is employed to prevent fish from being drawn into turbine intakes. Performance monitoring and detailed, quantifiable performance criteria were frequently lacking. Fifty-two of the 66 projects (82%) with operating downstream fish passage measures had no performance monitoring requirements; 50 of 71 project operators (70%) indicated that no performance objectives had been specified for the mitigative measures. The authors found that comprehensive field studies needed to evaluate the effectiveness of fish passage devices have been rare. 16 refs., 8 figs

  14. Cowlitz Falls fish passage

    The upper Cowlitz was once home to native salmon and steelhead. But the combined impacts of overharvest, farming, logging and road building hammered fish runs. And in the 1960s, a pair of hydroelectric dams blocked the migration path of ocean-returning and ocean-going fish. The lower Cowlitz still supports hatchery runs of chinook, coho and steelhead. But some 200 river miles in the upper river basin--much of it prime spawning and rearing habitat--have been virtually cut off from the ocean for over 26 years. Now the idea is to trap-and-haul salmon and steelhead both ways and bypass previously impassable obstacles in the path of anadromous fish. The plan can be summarized, for the sake of explanation, in three steps: (1) trap and haul adult fish--collect ocean-returning adult fish at the lowermost Cowlitz dam, and truck them upstream; (2) reseed--release the ripe adults above the uppermost dam, and let them spawn naturally, at the same time, supplement these runs with hatchery born fry that are reared and imprinted in ponds and net pens in the watershed; (3) trap and haul smolts--collection the new generation of young fish as they arrive at the uppermost Cowlitz dam, truck them past the three dams, and release them to continue their downstream migration to the sea. The critical part of any fish-collection system is the method of fish attraction. Scientists have to find the best combination of attraction system and screens that will guide young fish to the right spot, away from the turbine intakes. In the spring of 1994 a test was made of a prototype system of baffles and slots on the upriver face of the Cowlitz Falls Dam. The prototype worked at 90% efficiency in early tests, and it worked without the kind of expensive screening devices that have been installed on other dams. Now that the success of the attraction system has been verified, Harza engineers and consultants will design and build the appropriate collection part of the system

  15. Quantum Superlattices, Wannier Stark Ladders and the 'Resonance' technique

    Papageorgiou, C D; Raptis, T E

    2016-01-01

    We present a new method for solving the Schrodinger equation using the Lossless Transmission Line Model (LTL). The LTL model although extensively used in fiber optics and optical fiber design, it has not yet found application in solid state problems. We develop the transformation theory mapping the wave equation to LTL and we apply the model to the case of a solid state periodic lattice. We extend the theory with an additional Wannier-Stark term and we show with results the flexibility and the strength of the technique. The advantages of the method for arbitrary potentials are also stressed.

  16. Fish Facts

    ... fish because they worry about mercury in seafood. Mercury is a metal that, at high levels, can harm the brain of your unborn baby even before he or she is conceived. Yet many types of seafood have little or no mercury at all. So your risk of mercury exposure ...

  17. Do Fish Enhance Tank Mixing?

    Rasmussen, Michael R.; Laursen, Jesper; Craig, Steven R.;

    2005-01-01

    The design of fish rearing tanks represents a critical stage in the development of optimal aquaculture systems, especially in the context of recirculating systems. Poor hydrodynamics can compromise water quality, waste management and the physiology and behaviour of fish, and thence, production...... determine the impact of fish presence upon tank hydrodynamics, Rhodamine fluorometry was employed to examine mixing within a recirculating aquaculture system. Two different methods were compared, traditional, outlet-based measurements and a technique that employed in-tank data acquisition. Circular tanks...... were employed during data collection either in the presence or absence of xperimental fish-red drum Sciaenops ocellatus (n =36; 5 kg total wet wt); and at two flow rates. Irrespective of flow rate, the presence of fish dramatically enhanced the mixing process ( P< 0.001), with mixing times in tanks...

  18. Belle II SVD ladder assembly procedure and electrical qualification

    Adamczyk, K.; Aihara, H.; Angelini, C.; Aziz, T.; Babu, Varghese; Bacher, S.; Bahinipati, S.; Barberio, E.; Baroncelli, T.; Basith, A. K.; Batignani, G.; Bauer, A.; Behera, P. K.; Bergauer, T.; Bettarini, S.; Bhuyan, B.; Bilka, T.; Bosi, F.; Bosisio, L.; Bozek, A.; Buchsteiner, F.; Casarosa, G.; Ceccanti, M.; Červenkov, D.; Chendvankar, S. R.; Dash, N.; Divekar, S. T.; Doležal, Z.; Dutta, D.; Forti, F.; Friedl, M.; Hara, K.; Higuchi, T.; Horiguchi, T.; Irmler, C.; Ishikawa, A.; Jeon, H. B.; Joo, C.; Kandra, J.; Kang, K. H.; Kato, E.; Kawasaki, T.; Kodyš, P.; Kohriki, T.; Koike, S.; Kolwalkar, M. M.; Kvasnička, P.; Lanceri, L.; Lettenbicher, J.; Mammini, P.; Mayekar, S. N.; Mohanty, G. B.; Mohanty, S.; Morii, T.; Nakamura, K. R.; Natkaniec, Z.; Negishi, K.; Nisar, N. K.; Onuki, Y.; Ostrowicz, W.; Paladino, A.; Paoloni, E.; Park, H.; Pilo, F.; Profeti, A.; Rao, K. K.; Rashevskaya, I.; Rizzo, G.; Rozanska, M.; Sandilya, S.; Sasaki, J.; Sato, N.; Schultschik, S.; Schwanda, C.; Seino, Y.; Shimizu, N.; Stypula, J.; Tanaka, S.; Tanida, K.; Taylor, G. N.; Thalmeier, R.; Thomas, R.; Tsuboyama, T.; Uozumi, S.; Urquijo, P.; Vitale, L.; Volpi, M.; Watanuki, S.; Watson, I. J.; Webb, J.; Wiechczynski, J.; Williams, S.; Würkner, B.; Yamamoto, H.; Yin, H.; Yoshinobu, T.

    2016-07-01

    The Belle II experiment at the SuperKEKB asymmetric e+e- collider in Japan will operate at a luminosity approximately 50 times larger than its predecessor (Belle). At its heart lies a six-layer vertex detector comprising two layers of pixelated silicon detectors (PXD) and four layers of double-sided silicon microstrip detectors (SVD). One of the key measurements for Belle II is time-dependent CP violation asymmetry, which hinges on a precise charged-track vertex determination. Towards this goal, a proper assembly of the SVD components with precise alignment ought to be performed and the geometrical tolerances should be checked to fall within the design limits. We present an overview of the assembly procedure that is being followed, which includes the precision gluing of the SVD module components, wire-bonding of the various electrical components, and precision three dimensional coordinate measurements of the jigs used in assembly as well as of the final SVD modules.

  19. The Fishing Cat

    孙雅飞; 乐伟国

    2008-01-01

    @@ 一、故事内容 A cat goes fishing every day. He wants to eat fish, but he can't catch any fish. One day, he goes to the river as usual. Suddenly, a fish comes out. He catches the fish and putsthe fish in the basket. He's very happy, but he forgest to put the lid on the basket.

  20. Microbiological spoilage of fish and fish products

    Gram, Lone; Huss, Hans Henrik

    1996-01-01

    Spoilage of fresh and lightly preserved fish products is caused by microbial action. This paper reviews the current knowledge in terms of the microbiology of fish and fish products with particular emphasis on identification of specific spoilage bacteria and the qualitative and quantitative...... biochemical indicators of spoilage. Shewanzella putrefaciens and Pseudomonas spp. are the specific spoilage bacteria of iced fresh fish regardless of the origin of the fish. Modified atmosphere stored marine fish from temperate waters are spoiled by the CO2 resistant Photobacterium phosphoreum whereas Gram......- positive bacteria are likely spoilers of CO2 packed fish from fresh or tropical waters. Fish products with high salt contents may spoil due to growth of halophilic bacteria (salted fish) or growth of anaerobic bacteria and yeasts (barrel salted fish). Whilst the spoilage of fresh and highly salted fish...

  1. Hood River and Pelton Ladder Evaluation Studies and Hood River Fish Habitat Project, 1998 Annual Progress Report.

    Lambert, Michael B.; McCanna, Joseph P.; Jennings, Mick

    1999-12-01

    The Hood River subbasin is home to four species of anadromous salmonids: chinook salmon (Oncorhynchus tshawytscha), coho salmon (Oncorhynchus kisutch), steelhead (Oncorhynchus mykiss), and sea run cutthroat trout (Salmo clarki). Indigenous spring chinook salmon were extirpated during the late 1960's. The naturally spawning spring chinook salmon currently present in the subbasin are progeny of Deschutes stock. Historically, the Hood River subbasin hatchery steelhead program utilized out-of-basin stocks for many years. Indigenous stocks of summer and winter steelhead were listed in March 1998 by National Marine Fisheries Service (NMFS) under the Endangered Species Act (ESA) as a ''Threatened'' Species along with similar genetically similar steelhead in the Lower Columbia Basin.

  2. Oral vaccination of fish

    Embregts, Carmen W.E.; Forlenza, Maria

    2016-01-01

    The limited number of oral vaccines currently approved for use in humans and veterinary species clearly illustrates that development of efficacious and safe oral vaccines has been a challenge not only for fish immunologists. The insufficient efficacy of oral vaccines is partly due to antigen breakdown in the harsh gastric environment, but also to the high tolerogenic gut environment and to inadequate vaccine design. In this review we discuss current approaches used to develop oral vaccines fo...

  3. The cause of Ladder-like bands in the STR profiling of the highly degraded remains%降解检材STR分型Ladder-Like条带形成原因的探讨

    楼迪栋; 余纯应; 黄代新; 赵贵森; 任文; 杨庆恩

    2005-01-01

    目的探讨降解DNA短串联重复序列PCR扩增产物在PAGE中Ladder-Like条带的形成原因.方法用一组人工合成的不同长度的D8S1179DNA单链,模拟降解检材中的断裂DNA;利用John M设计的D8S1179引物对模拟模板的DNA单链进行PCR扩增,PAGE分离.结果不同模拟模板的DNA单链的组合可以扩增出不同的Ladder-Like条带.结论短串联重复序列Ladder-like条带是PCR过程中降解DNA多态区互补扩增的产物.

  4. Fish hemoglobins

    P.C. de Souza

    2007-06-01

    Full Text Available Vertebrate hemoglobin, contained in erythrocytes, is a globular protein with a quaternary structure composed of 4 globin chains (2 alpha and 2 beta and a prosthetic group named heme bound to each one. Having myoglobin as an ancestor, hemoglobin acquired the capacity to respond to chemical stimuli that modulate its function according to tissue requirements for oxygen. Fish are generally submitted to spatial and temporal O2 variations and have developed anatomical, physiological and biochemical strategies to adapt to the changing environmental gas availability. Structurally, most fish hemoglobins are tetrameric; however, those from some species such as lamprey and hagfish dissociate, being monomeric when oxygenated and oligomeric when deoxygenated. Fish blood frequently possesses several hemoglobins; the primary origin of this finding lies in the polymorphism that occurs in the globin loci, an aspect that may occasionally confer advantages to its carriers or even be a harmless evolutionary remnant. On the other hand, the functional properties exhibit different behaviors, ranging from a total absence of responses to allosteric regulation to drastic ones, such as the Root effect.

  5. THE PAN-STARRS 1 PHOTOMETRIC REFERENCE LADDER, RELEASE 12.01

    As of 2012 January 21, the Pan-STARRS 1 3π Survey has observed the 3/4 of the sky visible from Hawaii with a minimum of 2 and mean of 7.6 observations in five filters, g P1, r P1, i P1, z P1, y P1. Now at the end of the second year of the mission, we are in a position to make an initial public release of a portion of this unprecedented data set. This article describes the PS1 Photometric Ladder, Release 12.01. This is the first of a series of data releases to be generated as the survey coverage increases and the data analysis improves. The Photometric Ladder has rungs every hour in right ascension and at four intervals in declination. We will release updates with increased area coverage (more rungs) from the latest data set until the PS1 survey and the final re-reduction are completed. The currently released catalog presents photometry of ∼1000 objects per square degree in the rungs of the ladder. Saturation occurs at g P1, r P1, i P1 ∼ 13.5; z P1 ∼ 13.0; and y P1 ∼ 12.0. Photometry is provided for stars down to g P1, r P1, i P1 ∼ 19.1 in the AB system. This data release depends on the rigid 'Ubercal' photometric calibration using only the photometric nights, with systematic uncertainties of (8.0, 7.0, 9.0, 10.7, 12.4) mmag in (g P1, r P1, i P1, z P1, y P1). Areas covered only with lower quality nights are also included, and have been tied to the Ubercal solution via relative photometry; photometric accuracy of the non-photometric regions is lower and should be used with caution.

  6. Magneto-optical polarization rotation in a ladder-type atomic system for tunable offset locking

    Parniak, Michał; Wasilewski, Wojciech

    2016-01-01

    We demonstrate an easily tunable locking scheme for stabilizing frequency-sum of two lasers on a two-photon ladder transition based on polarization rotation in warm rubidium vapors induced by magnetic field and circularly polarized driving field. In principle unlimited tunability of the two-photon offset frequency is due to strong splitting and shifting of magnetic states in external field. We achieve two-photon detuning of 120 MHz with the single-photon detuning of up to 20 GHz, as well as strong rotation signal.

  7. Cocaine Is Low on the Value Ladder of Rats: Possible Evidence for Resilience to Addiction

    Cantin, L; Lenoir, M.; Augier, E.; Vanhille, N.; Dubreucq, S.; Serre, F.; Vouillac, Caroline; Ahmed, Serge,

    2010-01-01

    Background Assessing the relative value of cocaine and how it changes with chronic drug use represents a long-standing goal in addiction research. Surprisingly, recent experiments in rats – by far the most frequently used animal model in this field – suggest that the value of cocaine is lower than previously thought. Methodology/Principal Findings Here we report a series of choice experiments that better define the relative position of cocaine on the value ladder of rats (i.e., preference ran...

  8. Coupling-intensity effects in ladder-type electromagnetically induced transparency of rubidium atoms

    We have studied electromagnetically induced transparency (EIT) in the 5S1/2-5P3/2-5D5/2 ladder-type system of Rb. We observed relative changing magnitude of EIT hyperfine structures depending on not only the polarizations of the lasers but also the intensity of the coupling laser. The coupling-intensity effects are attributed to the nonlinear increase of the EIT signal to the coupling intensity. EIT signals nonlinear on the coupling intensity are analyzed by considering coherent interaction between atom and laser fields

  9. Coherent Phase Control of Multiphoton Ionization in Three-Level Ladder-Type System

    ZHANG Shi-An; CHEN Yu-Ting; WANG Zu-Geng; SUN Zhen-Rong

    2009-01-01

    We present the theoretical investigation of photoelectron spectroscopy resulting from the strong field induced multiphoton ionization in a typical three-level ladder-style system.Our theoretical results show that the photoelectron spectral structure can be alternatively steered by spectral phase modulation.This physical mechanism for strong field quantum control is explicitly exploited by the time-dependent dressed state population.It is concluded that the phase-shaped laser pulses can be used to selectively manipulate the multiphoton ionization process in complicated quantum systems.

  10. Vibrational ladder-climbing in surface-enhanced, ultrafast infrared spectroscopy.

    Kraack, Jan Philip; Hamm, Peter

    2016-06-28

    In a recent work (J. Phys. Chem. C 2016, 120, 3350-3359), we have introduced the concept of surface-enhanced, two-dimensional attenuated total reflectance (2D ATR IR) spectroscopy with modest enhancement factors (450), which allows for multi-quantum IR excitation of adsorbed molecules, a process known as "vibrational ladder-climbing", even for weakly absorbing (ε ultrafast dynamics of highly excited vibrational states or surface-sensitive coherent control experiments of ground-state reactions at solid-liquid interfaces. PMID:27265518

  11. A Study of Regional Brand Positioning Strategy for Linhai Orange Based on Soft Laddering

    Ying; TAO; Yueli; ZHANG

    2015-01-01

    In this paper,Means-End Chain Theory is used for the positioning strategy study on regional brand of Linhai Orange,and based on soft laddering method,33 Linhai Orange consumers are interviewed. By understanding the individual needs of Linhai Orange consumers,this paper establishes the " Attributes-Consequences-Value" matrix and hierarchical value map. This study aims to explore the regional brand positioning strategy of Linhai Orange,in order to promote the regional brand building and extension of Linhai Orange and enhance the sustained regional brand development of Linhai Orange.

  12. Quantum Entanglement in the S=1/2 Spin Ladder with Ring Exchange

    Song, Jun-Liang; Gu, Shi-Jian; Lin, Hai-Qing

    2006-01-01

    In this paper we study the concurrence and the block-block entanglement in the $S=1/2$ spin ladder with four-spin ring exchange by the exact diagonalization method of finite cluster of spins. The relationship between the global phase diagram and the ground-state entanglement is investigated. It is shown that the block-block entanglement of different block size and geometry manifests richer information of the system. We find that the extremal point of the two-site block-block entanglement on t...

  13. Comment on "Metal-Insulator Transition in an Aperiodic Ladder Network: An Exact Result"

    Flach, Sergej; Danieli, Carlo

    2014-01-01

    Sil, Maiti, and Chakrabarti (SMC) (Phys. Rev. Lett. 101, 076803 (2008), arXiv:0801.2670) introduce an aperiodic two-leg ladder network composed of atomic sites with on-site potentials distributed according to a quasiperiodic Aubry-Andre potential. SMC claim the existence of multiple mobility edges, i.e. metal-insulator transitions at multiple values of the Fermi energy. SMC use numerical calculations of the conductance and den- sity of states, and an analytical result in a limiting case. In t...

  14. Emergent Interacting Spin Islands in a Depleted Strong-Leg Heisenberg Ladder

    Schmidiger, D.; Povarov, K. Yu.; Galeski, S.; Reynolds, N.; Bewley, R.; Guidi, T.; Ollivier, J.; Zheludev, A.

    2016-06-01

    Properties of the depleted Heisenberg spin ladder material series (C7 H10 N )2Cu1 -zZnz Br4 have been studied by the combination of magnetic measurements and neutron spectroscopy. Disorder-induced degrees of freedom lead to a specific magnetic response, described in terms of emergent strongly interacting "spin island" objects. The structure and dynamics of the spin islands is studied by high-resolution inelastic neutron scattering. This allows us to determine their spatial shape and to observe their mutual interactions, manifested by strong spectral in-gap contributions.

  15. 基于Starling的捕鱼游戏的设计与开发%Design and Development of the Fishing Game Based on Starling

    俞琳琳

    2014-01-01

    In the rapid development of mobile industry today,mobile phone games have gradually become an indispensable part of people's life.Intelligent mobile phone appearance,is to provide a more rapid development of the platform and opportunity to the mobile phone game.This paper mainly introduces the process of developing a starling based framework for the android platform game fishing.Through the analysis of the planning and demand for the game,focuses on the design and realization of the key module of the game.Finally introduced the game releases and configuration,and the game was summarized,put forward the deficiencies and shortcomings and future expectation.%在移动产业高速发展的今天,手机游戏已经逐渐成为人们生活中必不可少的一部分。而智能手机的出现,更是给手机游戏提供了高速发展的平台和契机。本文主要介绍了一款基于Starling框架的安卓平台的捕鱼游戏的开发过程。首先,介绍了游戏的策划与需求分析,其次,重点介绍了游戏的主要模块的设计与实现,最后,介绍了游戏的发布及配置方法。

  16. Implementability of two-qubit unitary operations over the butterfly network and the ladder network with free classical communication

    We investigate distributed implementation of two-qubit unitary operations over two primitive networks, the butterfly network and the ladder network, as a first step to apply network coding for quantum computation. By classifying two-qubit unitary operations in terms of the Kraus-Cirac number, the number of non-zero parameters describing the global part of two-qubit unitary operations, we analyze which class of two-qubit unitary operations is implementable over these networks with free classical communication. For the butterfly network, we show that two classes of two-qubit unitary operations, which contain all Clifford, controlled-unitary and matchgate operations, are implementable over the network. For the ladder network, we show that two-qubit unitary operations are implementable over the network if and only if their Kraus-Cirac number do not exceed the number of the bridges of the ladder

  17. Implementability of two-qubit unitary operations over the butterfly network and the ladder network with free classical communication

    Akibue, Seiseki [Department of Physics, Graduate School of Science, The University of Tokyo, Tokyo (Japan); Murao, Mio [Department of Physics, Graduate School of Science, The University of Tokyo, Tokyo, Japan and NanoQuine, The University of Tokyo, Tokyo (Japan)

    2014-12-04

    We investigate distributed implementation of two-qubit unitary operations over two primitive networks, the butterfly network and the ladder network, as a first step to apply network coding for quantum computation. By classifying two-qubit unitary operations in terms of the Kraus-Cirac number, the number of non-zero parameters describing the global part of two-qubit unitary operations, we analyze which class of two-qubit unitary operations is implementable over these networks with free classical communication. For the butterfly network, we show that two classes of two-qubit unitary operations, which contain all Clifford, controlled-unitary and matchgate operations, are implementable over the network. For the ladder network, we show that two-qubit unitary operations are implementable over the network if and only if their Kraus-Cirac number do not exceed the number of the bridges of the ladder.

  18. Multi-mode traffic-induced vibrations in composite ladder-deck bridges under heavy moving vehicles

    Camara, A.; Ruiz-Teran, A. M.

    2015-10-01

    Composite (steel-concrete) ladder-decks represent one of the most common solutions in road bridges nowadays. In these structures the Serviceability Limit State (SLS) of vibrations is traditionally ignored or roughly addressed by means of simple static deflection-based approaches, inherently assuming that the vibrations are controlled by the fundamental longitudinal mode. This work demonstrates that a wide range of high-order vibrational modes, involving the transverse flexure of the slab between longitudinal girders, govern the accelerations recorded in the deck and inside the vehicles. In addition, a new methodology for analysing the Vehicle-Bridge Interaction is proposed, including the approaching platforms, the transition slabs, and the bridge joints. The results suggest that the riding comfort for vehicle users is specially affected by direct effects on the wheels, like the road roughness and possible construction misalignments at the bridge joints, as well as low-frequency vibrations coming from the deck in short or slender bridges. The filtering effects resulting from the average of the response in time and in space when calculating the root mean square acceleration are also explored, and new design parameters are provided. In addition, several structural features (such as the depth and spacing of the longitudinal and transverse steel beams, the thickness of the concrete slab, and the stiffness of the cantilever cross beams at the diaphragm sections) have been studied, and a set of new design criteria has been established. It has been demonstrated that the transverse flexibility of the deck (specially influenced by the support conditions and the slab thickness) is critically important for the users' (pedestrians and vehicle passengers) comfort, as it controls the aforementioned high-order vibrational modes which govern the dynamic response.

  19. Duration of pregnancy in relation to fish oil supplementation and habitual fish intake: a randomised clinical trial with fish oil

    Olsen, SF; Østerdal, ML; Salvig, JD;

    2007-01-01

    OBJECTIVE: To examine the effect of fish oil supplementation on duration of pregnancy, conditional on the woman's habitual fish intake. DESIGN: Multicentre 1:1 randomised clinical trial of effect of fish oil in a high-risk population of pregnant women in whom habitual fish intake was assessed at...... suspicion of IUGR or threatening preeclampsia in the current pregnancy (group 3, n=106). Women were stratified into low, middle, or high fish consumers. METHODS: The intervention group received fish oil capsules providing 2.7 g long-chain n-3 fatty acids per day (n-3 poly unsaturated fatty acids (PUFA......)) from around week 20 (groups 1 and 2) or 6.3 g n-3 PUFA from week 33 (group 3). The control regimen was capsules with olive oil. Effect on timing of spontaneous delivery was examined by Cox regression, assuming elective delivery (occurring in 40%) as a censoring event. Analyses of effect of fish oil...

  20. Fish Tales

    This talk is about fishing and the friendships that have resulted in its pursuit. It is also about theoretical physics, and the relationship of imagination and fantasy to the establishment of ideas about nature. Fishermen, like theoretical physicists, are well known for their inventive imaginations. Perhaps neither are as clever as sailors, who conceived of the mermaid. If one doubts the power of this fantasy, one should remember the ghosts of the many sailors who drowned pursuing these young nymphs. An extraordinary painting by J. Waterhouse is shown as Fig. 1. The enchantment of a mermaid must reflect an extraordinary excess of imagination on the part of the sailor, perhaps together with an impractical turn of mind. A consummated relationship with a mermaid is after all, by its very nature a fantasy incapable of realization. To a theoretical physicist, she is symbolic of many ideas we develop. There are many truths known to fisherman in which one might also find parallels to the goals of scientists: (1) A fish is the only animal that keeps growing after its death; (2) Nothing makes a fish bigger than almost being caught; (3) ''...of all the liars among mankind, the fisherman is the most trustworthy.'' (William Sherwood Fox, in Silken Lines and Silver Hooks); and (4) Men and fish are alike. They both get into trouble when they open their mouths. These quotes may be interpreted as reflecting skepticism regarding the honesty of fisherman, and probably do not reflect adequate admiration for a creative imagination. Is it fair to criticize a person for believing a falsehood that he or she sincerely believes to be true? The fisherman simultaneously invents the lie, and believes in it himself. The parallel with theoretical physics is perhaps only approximate, although we physicists may invent stories that we come to believe, on some rare occasions our ideas actually correspond to a more or less true descriptions of nature. These minor philosophical differences are not

  1. Fish Tales

    McLerran, L.

    2010-07-06

    This talk is about fishing and the friendships that have resulted in its pursuit. It is also about theoretical physics, and the relationship of imagination and fantasy to the establishment of ideas about nature. Fishermen, like theoretical physicists, are well known for their inventive imaginations. Perhaps neither are as clever as sailors, who conceived of the mermaid. If one doubts the power of this fantasy, one should remember the ghosts of the many sailors who drowned pursuing these young nymphs. An extraordinary painting by J. Waterhouse is shown as Fig. 1. The enchantment of a mermaid must reflect an extraordinary excess of imagination on the part of the sailor, perhaps together with an impractical turn of mind. A consummated relationship with a mermaid is after all, by its very nature a fantasy incapable of realization. To a theoretical physicist, she is symbolic of many ideas we develop. There are many truths known to fisherman in which one might also find parallels to the goals of scientists: (1) A fish is the only animal that keeps growing after its death; (2) Nothing makes a fish bigger than almost being caught; (3) ''...of all the liars among mankind, the fisherman is the most trustworthy.'' (William Sherwood Fox, in Silken Lines and Silver Hooks); and (4) Men and fish are alike. They both get into trouble when they open their mouths. These quotes may be interpreted as reflecting skepticism regarding the honesty of fisherman, and probably do not reflect adequate admiration for a creative imagination. Is it fair to criticize a person for believing a falsehood that he or she sincerely believes to be true? The fisherman simultaneously invents the lie, and believes in it himself. The parallel with theoretical physics is perhaps only approximate, although we physicists may invent stories that we come to believe, on some rare occasions our ideas actually correspond to a more or less true descriptions of nature. These minor philosophical

  2. Heat Conductivity of the Heisenberg Spin-1 /2 Ladder: From Weak to Strong Breaking of Integrability

    Steinigeweg, Robin; Herbrych, Jacek; Zotos, Xenophon; Brenig, Wolfram

    2016-01-01

    We investigate the heat conductivity κ of the Heisenberg spin-1 /2 ladder at finite temperature covering the entire range of interchain coupling J⊥, by using several numerical methods and perturbation theory within the framework of linear response. We unveil that a perturbative prediction κ ∝J⊥-2 , based on simple golden-rule arguments and valid in the strict limit J⊥→0 , applies to a remarkably wide range of J⊥, qualitatively and quantitatively. In the large J⊥ limit, we show power-law scaling of opposite nature, namely, κ ∝J⊥2. Moreover, we demonstrate the weak and strong coupling regimes to be connected by a broad minimum, slightly below the isotropic point at J⊥=J∥. Reducing temperature T , starting from T =∞ , this minimum scales as κ ∝T-2 down to T on the order of the exchange coupling constant. These results provide for a comprehensive picture of κ (J⊥,T ) of spin ladders.

  3. Some finite terms from ladder diagrams in three and four loop maximal supergravity

    Basu, Anirban

    2015-01-01

    We consider the finite part of the leading local interactions in the low energy expansion of the four graviton amplitude from the ladder skeleton diagrams in maximal supergravity on T^2, at three and four loops. At three loops, we express the D^8 R^4 and D^{10} R^4 amplitudes as integrals over the moduli space of an underlying auxiliary geometry. These amplitudes are evaluated exactly for special values of the the moduli of the auxiliary geometry, where the integrand simplifies. We also perform a similar analysis for the D^8 R^4 amplitude at four loops that arise from the ladder skeleton diagrams for a special value of a parameter in the moduli space of the auxiliary geometry. While the dependence of the amplitudes on the volume of the T^2 is very simple, the dependence on the complex structure of the T^2 is quite intricate. In some of the cases, the amplitude consists of terms each of which factorizes into a product of two SL(2,Z) invariant modular forms. While one of the factors is a non--holomorphic Eisens...

  4. Spinful fermionic ladders at incommensurate filling: Phase diagram, local perturbations, and ionic potentials

    We study the effect of external potential on transport properties of the fermionic two-leg ladder model. The response of the system to a local perturbation is strongly dependent on the ground state properties of the system and especially on the dominant correlations. We categorize all phases and transitions in the model (for incommensurate filling) and introduce “hopping-driven transitions” that the system undergoes as the inter-chain hopping is increased from zero. We also describe the response of the system to an ionic potential. The physics of this effect is similar to that of the single impurity, except that the ionic potential can affect the bulk properties of the system and in particular induce true long range order. -- Highlights: •We study low temperature electronic properties of a two leg ladder. •We find a wide variety of phase transitions as a function of model parameters. •We study the effect of impurities on these models. •Conductance may be very sensitive to the structure of these impurities

  5. Star formation relations and CO SLEDs across the J-ladder and redshift

    Greve, T R; Xilouris, E M; Weiss, A; Zhang, Z -Y; van der Werf, P; Aalto, S; Armus, L; Diaz-Santos, T; Evans, A S; Fischer, J; Gao, Y; Gonzalez-Alfonso, E; Harris, A; Henkel, C; Meijerink, R; Naylor, D A; Smith, H A; Spaans, M; Stacey, G J; Veilleux, S; Walter, F

    2014-01-01

    We present FIR-CO luminosity relations ($\\log L_{\\rm FIR} = \\alpha \\log L'_{\\rm CO} + \\beta$) for the full CO rotational ladder from J=1-0 to J=13-12 for 62 local (z 1) by including 35 (sub)-millimeter selected dusty star forming galaxies from the literature with robust CO observations. The addition of luminous starbursts at high redshifts enlarge the range of the FIR-CO luminosity relations towards the high-IR-luminosity end while also significantly increasing the small amount of mid-/high-J CO line data available prior to Herschel. This new data-set (both in terms of IR luminosity and J-ladder) reveals linear FIR-CO luminosity relations ($\\alpha \\sim 1$) for J=1-0 up to J=5-4, with a nearly constant normalisation ($\\beta \\sim 2$). This is expected from the (also) linear FIR-(molecular line) relations found for the dense gas tracer lines (HCN and CS), as long as the dense gas mass fraction does not vary strongly within our (merger/starburst)-dominated sample. However from J=6-5 and up to J=13-12 we find an ...

  6. Optimization of Vibration Reduction Ability of Ladder Tracks by FEM Coupled with ACO

    Hao Jin

    2015-01-01

    Full Text Available Ladder track, which has drawn increased attention in scientific communities, is an effective method for reducing vibrations from underground railways. In order to optimize the vibration reduction ability of ladder track, a new method, that is, the finite element method (FEM coupled with ant colony optimization (ACO, has been proposed in this paper. We describe how to build the FEM model verified by the vibration tests in the Track Vibration Abatement and Control Laboratory and how to couple the FEM with ACO. The density and elasticity modulus of the sleeper pad are optimized using this method. After optimization, the vibration acceleration level of the supporting platform in the 1–200 Hz range was reduced from 102.8 dB to 94.4 dB. The optimized density of the sleeper pad is 620 kg/m3, and the optimized elasticity modulus of the sleeper pad is 6.25 × 106 N/m2.

  7. Energy-efficient hydrogen separation by AB-type ladder-polymer molecular sieves

    Ghanem, Bader

    2014-07-19

    The synthesis, microstructures, and exceptional gas transport properties of two new soluble ladder polymers, polymers of intrinsic microporosity (TPIM-1 and TPIM-2) containing triptycene moieties substituted with branched isopropyl and linear propyl chains at the 9,10-bridgeheads were reported. The precursor A-B monomers were modified with an o -difluoride functionality for enhanced activation for nucleophilic aromatic substitution. In a Schlenk tube, a mixture of the A-B monomer, 18-crown-6, anhydrous DMF and anhydrous potassium carbonate was stirred at 155 °C under nitrogen atmosphere for 20 min followed by the addition of toluene. The reaction was continued for another 45 min and more toluene was added. After another 45 min the reaction mixture was cooled to room temperature and poured into methanol. Slow evaporation of filtered, dilute 3-5 wt% chloroform solutions from a leveled glass plate yielded isotropic polymer films. Dry membranes were soaked in methanol for 24 h, air-dried, and then heated at 120°C for 24 h under high vacuum to remove any traces of residual solvent. TPIM-1 exhibits simultaneous boosts in permeability and selectivity, which highlights the significant potential of an isopropyl-substituted triptycene moiety as a contortion center for ladder PIMs.

  8. Magnetic Precursor of the Pressure-Induced Superconductivity in Fe-Ladder Compounds.

    Chi, Songxue; Uwatoko, Yoshiya; Cao, Huibo; Hirata, Yasuyuki; Hashizume, Kazuki; Aoyama, Takuya; Ohgushi, Kenya

    2016-07-22

    The pressure effects on the antiferromagentic orders in iron-based ladder compounds CsFe_{2}Se_{3} and BaFe_{2}S_{3} have been studied using neutron diffraction. With identical crystal structure and similar magnetic structures, the two compounds exhibit highly contrasting magnetic behaviors under moderate external pressures. In CsFe_{2}Se_{3} the ladders are brought much closer to each other by pressure, but the stripe-type magnetic order shows no observable change. In contrast, the stripe order in BaFe_{2}S_{3} undergoes a quantum phase transition where an abrupt increase of Néel temperature by more than 50% occurs at about 1 GPa, accompanied by a jump in the ordered moment. With its spin structure unchanged, BaFe_{2}S_{3} enters an enhanced magnetic phase that bears the characteristics of an orbital selective Mott phase, which is the true neighbor of superconductivity emerging at higher pressures. PMID:27494496

  9. Fish habitat mitigation measures for hydrotechnical projects

    In recent years, the identification and mitigation of environmental impacts of hydrotechnical projects, particularly on fish and fish habitats, have become a major component of project planning and design. Potential impacts to fish and fish habitat may include increased fish mortality, decreased species diversity, and loss or decreases in fish production due to loss of habitat or alteration of its suitability. These impacts arise from flooding of riverine habitat, alteration of flow quantity and distribution, changes in morphology, and alteration of water quality, including suspended sediments, temperature, dissolved oxygen, and mercury. The results of a study for the Canadian Federal Department of Fisheries and Oceans Central and Arctic Region, examining fish habitat mitigation techniques for their applicability to hydrotechnical projects in Canada are summarized. The requirements for achievement and verification of the no net loss policy for a project are discussed. 10 refs., 2 tabs

  10. Motives, barriers and quality evaluation in fish consumption situations

    Brunsø, Karen; Verbeke, Wim; Olsen, Svein Ottar;

    2009-01-01

    Purpose - The purpose of this paper is to investigate motives and barriers for eating fish among light users and heavy users, to discuss consumer evaluation of fish quality, and to explore the existence of cross-cultural fish consumer  segments. Design/methodology/approach - Qualitative data were...... though fish consumption levels differ considerably. The main motives for eating fish are health and taste, while the main barriers are price perception, smell when cooking fish, and that fish does not deliver the same level of satiety as compared to meat. Big differences are found between countries and...

  11. Variability of fish consumption within the 10 European countries participating in the European Investigation into Cancer and Nutrition (EPIC) study

    Welch, A.A.; Lund, E.; Amiano, P.; Corronsoro, M.; Brustad, M.; Kumle, M.; Rodriguez, M.; Lasheras, C.; Janzon, L.; Jansson, J.; Luben, R.; Spencer, E.; Overvad, Kim; Tjønneland, Anne; Clavel, F.; Linseisen, J.; Klipstein-Grobusch, K.; Benetou, V.; Zavitsanos, X.; Tumino, R.; Galasso, R.; Bueno-de-Mesquita, H.B.; Ocké, M.C.; Charrondière, R.; Slimani, N.

    OBJECTIVE: To describe and compare the consumption of total fish (marine foods) and the fish sub-groups - white fish, fatty fish, very fatty fish, fish products and crustacea, in participants from the European Investigation into Cancer and Nutrition (EPIC) study. DESIGN: Cross-sectional analysis of...

  12. Fishing amplifies forage fish population collapses

    Essington, Timothy E.; Moriarty, Pamela E.; Froehlich, Halley E.; Hodgson, Emma E.; Koehn, Laura E.; Oken, Kiva L.; Siple, Margaret C.; Stawitz, Christine C.

    2015-01-01

    Forage fish support the largest fisheries in the world but also play key roles in marine food webs by transferring energy from plankton to upper trophic-level predators, such as large fish, seabirds, and marine mammals. Fishing can, thereby, have far reaching consequences on marine food webs unless safeguards are in place to avoid depleting forage fish to dangerously low levels, where dependent predators are most vulnerable. However, disentangling the contributions of fishing vs. natural processes on population dynamics has been difficult because of the sensitivity of these stocks to environmental conditions. Here, we overcome this difficulty by collating population time series for forage fish populations that account for nearly two-thirds of global catch of forage fish to identify the fingerprint of fisheries on their population dynamics. Forage fish population collapses shared a set of common and unique characteristics: high fishing pressure for several years before collapse, a sharp drop in natural population productivity, and a lagged response to reduce fishing pressure. Lagged response to natural productivity declines can sharply amplify the magnitude of naturally occurring population fluctuations. Finally, we show that the magnitude and frequency of collapses are greater than expected from natural productivity characteristics and therefore, likely attributed to fishing. The durations of collapses, however, were not different from those expected based on natural productivity shifts. A risk-based management scheme that reduces fishing when populations become scarce would protect forage fish and their predators from collapse with little effect on long-term average catches. PMID:25848018

  13. Got a Sick Fish?

    ... Welfare Veterinary Careers Public Health Got a sick fish? Fish with disease can show a variety of signs. If you notice your pet fish having any unusual disease signs, contact your veterinarian ...

  14. Fish tapeworm infection

    Fish tapeworm infection is an intestinal infection with the tapeworm parasite found in fish. ... The fish tapeworm ( Diphyllobothrium latum ) is the largest parasite that infects humans. Humans become infected when they eat raw ...

  15. Sport Fishing Regulations

    US Fish and Wildlife Service, Department of the Interior — The regulations for sport fishing on St. Vincent National Wildlife Refuge are outlined in this document. Fishing is only permitted from sunrise to sunset, and only...

  16. Effects of acoustic alarms, designed to reduce small cetacean bycatch in gillnet fisheries, on the behaviour of North Sea fish species in a large tank

    Kastelein, R.A.; Heul, S. van der; Veen, J. van der; Verboom, W.C.; Jennings, N.; Haan, D. de; Reijnders, P.J.H.

    2007-01-01

    World-wide many cetaceans drown incidentally in fishing nets. To reduce the unwanted bycatch in gillnets, pingers (acoustic alarms) have been developed that are attached to the nets. In the European Union, pingers will be made compulsory in some areas in 2005 and in others in 2007. However, pingers

  17. Using Task Data in Diagnostic Radiology. Research Report No. 8. Volume 1. Job Ladders: Assigning Tasks to Jobs.

    Gilpatrick, Eleanor

    This report on the results of the application of the Health Services Mobility Study (HSMS) task analysis method in diagnostic radiology describes several career ladders starting from the aide level in quality assurance or patient care, rising to the technician level, and then on to the radiologic technologist level, with options to continue to…

  18. Heat transport imaging in the spin-ladder compound Ca9La5Cu24O41

    All-optical heat transport imaging on the spin-ladder compound Ca9La5Cu24O41 is presented. A 'time-of-flight' principle is discussed along with its experimental verification which can be used to measure the bulk thermal diffusion constant. The results of the thermal imaging experiments clearly demonstrate anisotropic magnon heat transport

  19. A Study of Career Ladders and Manpower Development for Non-Management Personnel in the Food Service Industry.

    State Univ. of New York, Ithaca. School of Hotel Administration at Cornell Univ.

    Because of its failure to provide career ladders for non-management employees, the food service industry is facing increasingly severe manpower shortages and labor turnover. Unnecessary requirements bar entry workers from many jobs, and training opportunities leave much to be desired. This report identifies the problem areas and develops a model…

  20. Effect of vacuum-induced coherence on lasing without inversion in an equispaced three-level ladder system

    Jun Qian; Chengpu Liu; Shangqing Gong

    2005-01-01

    The effects of vacuum-induced coherence (VIC) on the properties of the absorption and gain of the probe field in an equispaced three-level ladder atomic system are investigated. It is found that lasing without inversion (LWI) is remarkably enhanced due to the effect of VIC in the case of the small incoherent pump rate.

  1. Detection of apoptotic DNA ladder in pig leukocytes and its precision using LM - PCR (ligation mediated polymerase chain reaction)

    Matalová, Eva; Španová, A.

    2002-01-01

    Roč. 71, č. 3 (2002), s. 163-168. ISSN 0001-7213 R&D Projects: GA ČR GA304/01/0850; GA AV ČR KSK6005114 Keywords : apoptosis * phagocytosis * DNA ladder Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.370, year: 2002

  2. The Bethe-Salpeter Equation for the Imaginary Part of the Scattering Amplitude in the Ladder Approximation

    Gadjiev, S A

    2001-01-01

    Scattering amplitude of fermions and bosons in the ladder approximation at high energies is investigated. For the imaginary part of the scattering amplitude the set of Bethe-Salpeter type integral equations is constructed. Solutions of this set in the Regge asymptotic form are found. The impact of mass parameters on the behavior of the amplitude at high energies is studied.

  3. Teachers' Career Ladder Policy in Ethiopia: An Opportunity for Professional Growth or ''a Stick Disguised as a Carrot?''

    Tekleselassie, Abebayehu A.

    2005-01-01

    In response to the ever-declining status of the teaching profession, and its adverse effects on the country's educational system, the Federal Ministry of Education in Ethiopia introduced a policy of the teachers' career ladder in 1994. While reformers believe that the introduction of the policy has improved the condition of the teaching…

  4. Resummation of in-medium ladder diagrams: s-wave effective range and p-wave interaction

    A recent work on the resummation of fermionic in-medium ladder diagrams to all orders is extended by considering the effective range correction in the s-wave interaction and a (spin-independent) p-wave contact-interaction. A two-component recursion generates the in-medium T-matrix at any order when off-shell terms spoil the factorization of multi-loop diagrams. The resummation to all orders is achieved in the form of a geometrical series for the particle-particle ladders, and through an arctangent-function for the combined particle-particle and hole-hole ladders. One finds that the effective range correction changes the results in the limit of large scattering length considerably, with the effect that the Bertsch parameter ξ n nearly doubles. Applications to the equation of state of neutron matter at low density are also discussed. For the p-wave contact-interaction the resummation to all orders is facilitated by decomposing tensorial loop-integrals with a transversal and a longitudinal projector. The enhanced attraction provided by the p-wave ladder series has its origin mainly in the coherent sum of Hartree and Fock contributions. (orig.)

  5. Fish welfare: Fish capacity to experience pain

    Vučinić Marijana

    2009-01-01

    Full Text Available Teleost fish possess similar nociceptive processing systems to those found in terrestrial vertebrates. It means that they react to potential painful stimuli in a similar manner as mammals and birds. However, the welfare of fish has been the focus of less research than that of higher vertebrates. Humans may affect the welfare of fish through fisheries, aquaculture and a number of other activities. There is scientific evidence to support the assumption that fish have the capacity to experience pain because they possess functional nociceptors, endogenous opioids and opioid receptors, brain structures involved in pain processing and pathways leading from nociceptors to higher brain structures. Also, it is well documented that some anaesthetics and analgesics may reduce nociceptive responses in fish. Behavioural indicators in fish such as lip-rubbing and rocking behaviours are the best proof that fish react to potential painful stimuli. This paper is an overview of some scientific evidence on fish capacity to experience pain.

  6. Dam crossing by migrating fish. State of the technique

    In the first part of this paper, the present state of design of fish ways is reviewed, focusing on the interest and the limits of each type of fish facility. The second part deals with downstream migration problems at hydroelectric power plants: fish damage in spillways and hydraulic turbines and design of fish screening and other diversionary techniques used to prevent entry of downstream migrant into intakes. 14 refs., 13 figs

  7. Fish for Feed vs Fish for Food

    Allan, Geoff L.

    2004-01-01

    Aquaculture is the fastest-growing food producing industry sector in the world. Demand for feed ingredients, particularly for preferred protein sources such as fishmeal, fish oil and ‘trash fish’, has also increased, raising questions about sustainability and uses of fish for aquaculture feeds or directly as human food. Approximately 30 million metric tonnes (MMT) of fish from capture fisheries are used each year to produce fishmeal and fish oil. The species used are not usually consumed dire...

  8. No Fishing Now,More Fish Later

    2011-01-01

    Fishing ban for ecological purposes starts on the Pearl River Since April1,a two-month ban on fishing has been imposed on the Pearl River valley in south China.It is the first fishing ban in this area with the purpose of preserving biodiversity in China’s third longest

  9. Fishing Fish Stem Cells and Nuclear Transplants

    Yunhan Hong

    2011-01-01

    Fish has been the subject of various research fields, ranging from ecology, evolution, physiology and toxicology to aquaculture. In the past decades fish has attracted considerable attention for functional genomics, cancer biology and developmental genetics, in particular nuclear transfer for understanding of cytoplasmic-nuclear relationship. This special issue reports on recent progress made in fish stem cells and nuclear transfer.

  10. From fishing to fish processing: Separation of fish from crustaceans in the Norway lobster-directed multispecies trawl fishery improves seafood quality

    Junita D Karlsen; Ludvig Ahm Krag; Christoffer Moesgaard Albertsen; Rikke Petri Frandsen

    2015-01-01

    Fishing gears have negative impacts on seafood quality, especially on fish in the mixed trawl fishery targeting Norway lobster (Nephrops norvegicus). In this fishery, which is worth about €80 millions in Denmark alone, the quality of fish can be significantly improved by simple gear changes. A trawl codend divided into an upper and lower codend was designed to separate fish from Norway lobster during the fishing process by encourage fish to swim into the upper codend by using a frame at the e...

  11. From fishing to fish processing: Separation of fish from crustaceans in the Norway lobster-directed multispecies trawl fishery improves seafood quality

    Karlsen, Junita Diana; Krag, Ludvig Ahm; Albertsen, Christoffer Moesgaard;

    2015-01-01

    Fishing gears have negative impacts on seafood quality, especially on fish in the mixed trawl fishery targeting Norway lobster (Nephrops norvegicus). In this fishery, which is worth about €80 millions in Denmark alone, the quality of fish can be significantly improved by simple gear changes. A...... trawl codend divided into an upper and lower codend was designed to separate fish from Norway lobster during the fishing process by encourage fish to swim into the upper codend by using a frame at the entrance of the lower codend. Separate codends for fish and Norway lobster in the same gear provide the...... caught in the standard codend: i) newly caught fish showed significantly less scale loss and discolourations and had significantly better texture; ii) landed fish had significantly better skin appearance and texture and significantly fewer discolourations; and iii) fillets showed significantly fewer...

  12. Surprises from the resummation of ladders in the ABJ(M) cusp anomalous dimension

    Bonini, Marisa; Griguolo, Luca; Preti, Michelangelo; Seminara, Domenico

    2016-05-01

    We study the cusp anomalous dimension in mathcal{N} = 6 ABJ(M) theory, identifying a scaling limit in which the ladder diagrams dominate. The resummation is encoded into a Bethe-Salpeter equation that is mapped to a Schroedinger problem, exactly solvable due to the surprising supersymmetry of the effective Hamiltonian. In the ABJ case the solution implies the diagonalization of the U( N ) and U( M ) building blocks, suggesting the existence of two independent cusp anomalous dimensions and an unexpected exponentiation structure for the related Wilson loops. While consistent with previous perturbative analysis, the strong coupling limit of our result does not agree with the string theory computation, emphasizing a difference with the analogous resummation in the mathcal{N} = 4 case.

  13. A renormalization approach to describe charge transport in quasiperiodic dangling backbone ladder (DBL)-DNA molecules

    Highlights: → One-step renormalization approach to describe the DBL-DNA molecule. → Electronic tight-binding Hamiltonian model. → A quasiperiodic sequence to mimic the DNA nucleotides arrangement. → Electronic transmission spectra. → I-V characteristics. -- Abstract: We study the charge transport properties of a dangling backbone ladder (DBL)-DNA molecule focusing on a quasiperiodic arrangement of its constituent nucleotides forming a Rudin-Shapiro (RS) and Fibonacci (FB) Poly (CG) sequences, as well as a natural DNA sequence (Ch22) for the sake of comparison. Making use of a one-step renormalization process, the DBL-DNA molecule is modeled in terms of a one-dimensional tight-binding Hamiltonian to investigate its transmissivity and current-voltage (I-V) profiles. Beyond the semiconductor I-V characteristics, a striking similarity between the electronic transport properties of the RS quasiperiodic structure and the natural DNA sequence was found.

  14. Two-step rational extensions of the harmonic oscillator: exceptional orthogonal polynomials and ladder operators

    The type III Hermite Xm exceptional orthogonal polynomial family is generalized to a double-indexed one Xm1,m2 (with m1 even and m2 odd such that m2 > m1) and the corresponding rational extensions of the harmonic oscillator are constructed by using second-order supersymmetric quantum mechanics. The new polynomials are proved to be expressible in terms of mixed products of Hermite and pseudo-Hermite ones, while some of the associated potentials are linked with rational solutions of the Painlevé IV equation. A novel set of ladder operators for the extended oscillators is also built and shown to satisfy a polynomial Heisenberg algebra of order m2 − m1 + 1, which may alternatively be interpreted in terms of a special type of (m2 − m1 + 2)th-order shape invariance property. (paper)

  15. Orbital Ordering and Spin-Ladder Formation in La2RuO5

    Eyert, V.; Ebbinghaus, S. G.; Kopp, T.

    2006-06-01

    The semiconductor-semiconductor transition of La2RuO5 is studied by means of augmented spherical wave electronic structure calculations as based on density-functional theory and the local density approximation. This transition has lately been reported to lead to orbital ordering and a quenching of the local spin magnetic moment. Our results hint towards an orbital ordering scenario which, markedly different from the previously proposed scheme, preserves the local S=1 moment at the Ru sites in the low-temperature phase. The unusual magnetic behavior is interpreted by the formation of spin ladders, which result from the structural changes occurring at the transition and are characterized by antiferromagnetic coupling along the rungs.

  16. Poisson equation for the three loop ladder diagram in string theory at genus one

    Basu, Anirban

    2016-01-01

    The three loop ladder diagram is a graph with six links and four cubic vertices that contributes to the D^{12} R^4 amplitude at genus one in type II string theory. The vertices represent the insertion points of vertex operators on the toroidal worldsheet and the links represent scalar Green functions connecting them. By using the properties of the Green function and manipulating the various expressions, we obtain a modular invariant Poisson equation satisfied by this diagram, with source terms involving one, two and three loop diagrams. Unlike the source terms in the Poisson equations for diagrams at lower orders in the momentum expansion or the Mercedes diagram, a particular source term involves a five point function containing a holomorphic and a antiholomorphic worldsheet derivative acting on different Green functions. We also obtain simple equalities between topologically distinct diagrams, and consider some elementary examples.

  17. ROMANIA: CLIMBING THE LADDER FOR A BETTER FUTURE. WHEN WILL IT REACH EU AND EURO AREA?

    Cristina Tatomir

    2011-12-01

    Full Text Available In this paper we assess the evolution of Romania’s economic convergence with the European Union (EU and Euro area, during the period 2000-2010. In order to determine the number of years required to reach the EU and Euro area average, we employ an economic convergence index, made up of real and structural convergence indexes. The analysis shows that Romania has been climbing the ladder in the process of catching-up with the EU and the Euro area until 2008 when, because of the international crisis, the economic convergence index started decreasing. We report that Romania will reach the EU average in April 2056 and the Euro area average in September 2062.As revealed by the analysis, it will take decadesto attain the European levels of economic convergence, this being the most important challenge for Romania on the long term.

  18. Massive 3-loop ladder diagrams for quarkonic local operator matrix elements

    Ablinger, Jakob; Schneider, Carsten [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation; Bluemlein, Johannes; Hasselhuhn, Alexander; Wissbrock, Fabian [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Klein, Sebastian [Technische Hochschule Aachen (Germany). Inst. fuer Theoretische Physik

    2012-06-15

    3-loop diagrams of the ladder-type, which emerge for local quarkonic twist-2 operator matrix elements, are computed directly for general values of the Mellin variable N using Appell-function representations and applying modern summation technologies provided by the package Sigma and the method of hyperlogarithms. In some of the diagrams generalized harmonic sums with {xi} element of {l_brace}1,1/2,2{r_brace} emerge beyond the usual nested harmonic sums. As the asymptotic representation of the corresponding integrals shows, the generalized sums conspire giving well behaved expressions for large values of N. These diagrams contribute to the 3-loop heavy flavor Wilson coefficients of the structure functions in deep-inelastic scattering in the region Q{sup 2} >> m{sup 2}.

  19. Calculating Three Loop Ladder and V-Topologies for Massive Operator Matrix Elements by Computer Algebra

    Ablinger, J; Blümlein, J; De Freitas, A; von Manteuffel, A; Schneider, C

    2015-01-01

    Three loop ladder and $V$-topology diagrams contributing to the massive operator matrix element $A_{Qg}$ are calculated. The corresponding objects can all be expressed in terms of nested sums and recurrences depending on the Mellin variable $N$ and the dimensional parameter $\\varepsilon$. Given these representations, the desired Laurent series expansions in $\\varepsilon$ can be obtained with the help of our computer algebra toolbox. Here we rely on generalized hypergeometric functions and Mellin-Barnes representations, on difference ring algorithms for symbolic summation, on an optimized version of the multivariate Almkvist-Zeilberger algorithm for symbolic integration, and on new methods to calculate Laurent series solutions of coupled systems of differential equations. The solutions can be computed for general coefficient matrices directly for any basis also performing the expansion in the dimensional parameter in case it is expressible in terms of indefinite nested product-sum expressions. This structural ...

  20. Trichromatic π-Pulse for Ultrafast Total Inversion of a Four-Level Ladder System

    Carles Serrat

    2015-11-01

    Full Text Available We present a numerical solution for complete population inversion in a four-level ladder system obtained by using a full π-pulse illumination scheme with resonant ultrashort phase-locked Gaussian laser pulses. We find that a set of pulse areas such as √3π , √2π , and √3π completely inverts the four-level system considering identical effective dipole coupling coefficients. The solution is consistent provided the involved electric fields are not too strong and it is amply accurate also in the case of diverse transition dipole moments. We study the effect of detuning and chirp of the laser pulses on the complete population inversion using the level structure of atomic sodium interacting with ps and fs pulses as an example. Our result opens the door for multiple applications such as efficient ultrashort pulse lasing in the UV or the engineering of quantum states for quantum computing.

  1. Vortex and Meissner phases of strongly-interacting bosons on a two-leg ladder

    Piraud, Marie; Heidrich-Meisner, Fabian; McCulloch, Ian P.; Greshner, Sebastian; Vekua, Temo; Schollwoeck, Ulrich

    2015-05-01

    We present the phase diagram of the strongly-interacting Bose-Hubbard model defined on a two-leg ladder geometry in the presence of a homogeneous flux. Our work was motivated by a recent experiment, which studied the same system, in the complementary regime of weak interactions. Based on extensive density matrix renormalization group simulations and a bosonization analysis, we have fully explored the parameter space spanned by filling, inter-leg tunneling, and flux. As a main result, we demonstrate the existence of gapless and gapped Meissner and vortex phases, with the gapped states emerging in Mott-insulating regimes. We calculate experimentally accessible observables such as chiral currents and vortex patterns and study their dependence on model parameters. The research of M.P. was supported by the European Union through the Marie-Curie grant ``ToPOL'' (No. 624033) (funded within FP7-MC- IEF).

  2. Energy dependence of the partial widths of the Wannier two-electron ionization ladder states

    The autoionization partial widths to the 1s channel of the Wannier two-electron ionization ladder of H- are computed quantum mechanically and are compared with earlier results obtained from qualitative or semiclassical arguments. The energy dependence of the partial width Γ(E) turns out to be ∼Ep, p = 3.4 ± 0.2, which, making the substitution E ∼ 1/n2, corresponds to Γ(n) ∼ n-6.8±0.4. This finding is in reasonable agreement with an earlier result of Γ(n) ∼ n-6.254, and in strong disagreement with the recently published result which is Γ(n) ∼ n-3.254. A new semiclassical theory confirms previous conjecture. (author)

  3. Preparation and structural studies of black glasses based on ladder-like silsesquioxanes

    Sitarz, M.; Jastrzębski, W.; Jeleń, P.; Długoń, E.; Gawęda, M.

    2014-11-01

    Black glasses are very interesting and promising materials from the point of their thermal and mechanical resistance. They can be used as protective layers on different kind of substrates, like steel, titanium, glasses. Controlling amount of carbon introduced to its structure is crucial for the properties of the material. Samples were prepared by sol-gel method using ladder-like silsesquioxanes as precursor and were heat-treated at 800 °C in inert atmosphere. Middle infrared, EDX and MAS NMR studies were carried out on heated samples to determine their structure. All methods confirmed presence of Si-C bonds in the resulting material. Theoretical MIR spectrum, of the constructed black glass model, allowed to make a precise assignment of bands in the experimental spectrum.

  4. Surprises from the resummation of ladders in the ABJ(M) cusp anomalous dimension

    Bonini, Marisa; Preti, Michelangelo; Seminara, Domenico

    2016-01-01

    We study the cusp anomalous dimension in N=6 ABJ(M) theory, identifying a scaling limit in which the ladder diagrams dominate. The resummation is encoded into a Bethe-Salpeter equation that is mapped to a Schroedinger problem, exactly solvable due to the surprising supersymmetry of the effective Hamiltonian. In the ABJ case the solution implies the diagonalization of the U(N) and U(M) building blocks, suggesting the existence of two independent cusp anomalous dimensions and an unexpected exponentiation structure for the related Wilson loops. While consistent with previous perturbative analysis, the strong coupling limit of our result does not agree with the string theory computation, emphasizing a difference with the analogous resummation in the N=4 case.

  5. A renormalization approach to describe charge transport in quasiperiodic dangling backbone ladder (DBL)-DNA molecules

    Sarmento, R.G. [Departamento de Fisica, Universidade Federal do Rio Grande do Norte, 59072-970 Natal, RN (Brazil); Fulco, U.L. [Departamento de Biofisica e Farmacologia, Universidade Federal do Rio Grande do Norte, 59072-970 Natal, RN (Brazil); Albuquerque, E.L., E-mail: eudenilson@gmail.com [Departamento de Biofisica e Farmacologia, Universidade Federal do Rio Grande do Norte, 59072-970 Natal, RN (Brazil); Caetano, E.W.S. [Instituto Federal de Educacao, Ciencia e Tecnologia do Ceara, 60040-531 Fortaleza, CE (Brazil); Freire, V.N. [Departamento de Fisica, Universidade Federal do Ceara, 60455-760 Fortaleza, CE (Brazil)

    2011-10-31

    Highlights: → One-step renormalization approach to describe the DBL-DNA molecule. → Electronic tight-binding Hamiltonian model. → A quasiperiodic sequence to mimic the DNA nucleotides arrangement. → Electronic transmission spectra. → I-V characteristics. -- Abstract: We study the charge transport properties of a dangling backbone ladder (DBL)-DNA molecule focusing on a quasiperiodic arrangement of its constituent nucleotides forming a Rudin-Shapiro (RS) and Fibonacci (FB) Poly (CG) sequences, as well as a natural DNA sequence (Ch22) for the sake of comparison. Making use of a one-step renormalization process, the DBL-DNA molecule is modeled in terms of a one-dimensional tight-binding Hamiltonian to investigate its transmissivity and current-voltage (I-V) profiles. Beyond the semiconductor I-V characteristics, a striking similarity between the electronic transport properties of the RS quasiperiodic structure and the natural DNA sequence was found.

  6. Tricritical Ising phase transition in a two-ladder Majorana fermion lattice

    Zhu, Xiaoyu; Franz, M.

    2016-05-01

    We introduce a two-ladder lattice model with interacting Majorana fermions that could be realized on the surfaces of a topological insulator film. We study this model with a combination of analytical and numerical techniques, and we find a phase diagram that features both gapless and gapped phases as well as interesting phase transitions including a quantum critical point in the tricritical Ising (TCI) universality class. The latter occurs at an intermediate-coupling strength at a meeting point of a first-order transition line and an Ising critical line, and it is known to be described by a superconformal field theory with central charge c =7/10 . We discuss the experimental feasibility of constructing the model and tuning parameters to the vicinity of the TCI point where signatures of the elusive supersymmetry can be observed.

  7. Coherent population transfer between uncoupled or weakly coupled states in ladder-type superconducting qutrits.

    Xu, H K; Song, C; Liu, W Y; Xue, G M; Su, F F; Deng, H; Tian, Ye; Zheng, D N; Han, Siyuan; Zhong, Y P; Wang, H; Liu, Yu-Xi; Zhao, S P

    2016-01-01

    Stimulated Raman adiabatic passage offers significant advantages for coherent population transfer between uncoupled or weakly coupled states and has the potential of realizing efficient quantum gate, qubit entanglement and quantum information transfer. Here we report on the realization of the process in the superconducting Xmon and phase qutrits-two ladder-type three-level systems in which the ground state population is coherently transferred to the second excited state via the dark state subspace. We demonstrate that the population transfer efficiency is no less than 96% and 67% for the two devices, which agree well with the numerical simulation of the master equation. Population transfer via stimulated Raman adiabatic passage is significantly more robust against variations of the experimental parameters compared with that via the conventional resonant π pulse method. Our work opens up a new venue for exploring the process for quantum information processing using the superconducting artificial atoms. PMID:27009972

  8. Dressed excitonic states and quantum interference in a three-level quantum dot ladder system

    Gerardot, B D; Brunner, D; Dalgarno, P A; Warburton, R J [School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Karrai, K [Center for NanoScience and Department fuer Physik der LMU, Geschwister-Scholl-Platz 1, 80539 Munich (Germany); Badolato, A [Institute of Quantum Electronics, ETH Zurich, 8093 Zurich (Switzerland); Petroff, P M [Materials Department, University of California, Santa Barbara, CA 93106 (United States)], E-mail: b.d.gerardot@hw.ac.uk

    2009-01-15

    We observe dressed states and quantum interference effects in a strongly driven three-level quantum dot ladder system. The effect of a strong coupling field on one dipole transition is measured by a weak probe field on the second dipole transition using differential reflection. When the coupling energy is much larger than both the homogeneous and inhomogeneous linewidths an Autler-Townes splitting is observed. Significant differences are observed when the transitions resonant with the strong and weak fields are swapped, particularly when the coupling energy is nearly equal to the measured linewidth. This result is attributed to quantum interference: destructive or constructive interference with modest visibility is observed depending on the pump/probe geometry. The data demonstrate that coherence of both the bi-exciton and the exciton is maintained in this solid-state system, even under intense illumination, which is crucial for prospects in quantum information processing and nonlinear optical devices.

  9. Commutation-relation-preserving ladder operators for propagating optical fields in nonuniform lossy media

    Partanen, Mikko; Häyrynen, Teppo; Tulkki, Jukka;

    2015-01-01

    We have recently developed a quantized fluctuational electrodynamics (QFED) formalism to describe the quantum aspects of local thermal balance formation and to formulate the electromagnetic field ladder operators so that they no longer exhibit the anomalies reported for resonant structures. Here we...... show how the QFED can be used to resolve between the left and right propagating fields to bridge the QFED and the quantum optical input-output relations commonly used to describe selected quantum aspects of resonators. The generalized model introduces a density of states concept describing interference...... effects, which is instrumental in allowing an unambiguous separation of the fields and related quantum operators into left and right propagating parts. In addition to providing insight on the quantum treatment of interference, our results also provide the conclusive resolution of the long-standing enigma...

  10. Commutation-relation-preserving ladder operators for propagating optical fields in nonuniform lossy media

    Partanen, Mikko; Häyrynen, Teppo; Tulkki, Jukka; Oksanen, Jani

    2015-09-01

    We have recently developed a quantized fluctuational electrodynamics (QFED) formalism to describe the quantum aspects of local thermal balance formation and to formulate the electromagnetic field ladder operators so that they no longer exhibit the anomalies reported for resonant structures. Here we show how the QFED can be used to resolve between the left and right propagating fields to bridge the QFED and the quantum optical input-output relations commonly used to describe selected quantum aspects of resonators. The generalized model introduces a density of states concept describing interference effects, which is instrumental in allowing an unambiguous separation of the fields and related quantum operators into left and right propagating parts. In addition to providing insight on the quantum treatment of interference, our results also provide the conclusive resolution of the long-standing enigma of the anomalous commutation relations of partially confined propagating fields.

  11. Some finite terms from ladder diagrams in three and four loop maximal supergravity

    Basu, Anirban

    2015-10-01

    We consider the finite part of the leading local interactions in the low energy expansion of the four graviton amplitude from the ladder skeleton diagrams in maximal supergravity on T 2, at three and four loops. At three loops, we express the {D}8{{R}}4 and {D}10{{R}}4 amplitudes as integrals over the moduli space of an underlying auxiliary geometry. These amplitudes are evaluated exactly for special values of the the moduli of the auxiliary geometry, where the integrand simplifies. We also perform a similar analysis for the {D}8{{R}}4 amplitude at four loops that arise from the ladder skeleton diagrams for a special value of a parameter in the moduli space of the auxiliary geometry. While the dependence of the amplitudes on the volume of the T 2 is very simple, the dependence on the complex structure of the T 2 is quite intricate. In some of the cases, the amplitude consists of terms each of which factorizes into a product of two {SL}(2,{{Z}}) invariant modular forms. While one of the factors is a non-holomorphic Eisenstein series, the other factor splits into a sum of modular forms each of which satisfies a Poisson equation on moduli space with source terms that are bilinear in the Eisenstein series. This leads to several possible perturbative contributions unto genus 5 in type II string theory on S1. Unlike the one and two loop supergravity analysis, these amplitudes also receive non-perturbative contributions from bound states of three D-(anti)instantons in the IIB theory.

  12. Cocaine Is Low on the Value Ladder of Rats: Possible Evidence for Resilience to Addiction

    Dubreucq, Sarah; Serre, Fuschia; Vouillac, Caroline; Ahmed, Serge H.

    2010-01-01

    Background Assessing the relative value of cocaine and how it changes with chronic drug use represents a long-standing goal in addiction research. Surprisingly, recent experiments in rats – by far the most frequently used animal model in this field – suggest that the value of cocaine is lower than previously thought. Methodology/Principal Findings Here we report a series of choice experiments that better define the relative position of cocaine on the value ladder of rats (i.e., preference rank-ordering of different rewards). Rats were allowed to choose either taking cocaine or drinking water sweetened with saccharin – a nondrug alternative that is not biologically essential. By systematically varying the cost and concentration of sweet water, we found that cocaine is low on the value ladder of the large majority of rats, near the lowest concentrations of sweet water. In addition, a retrospective analysis of all experiments over the past 5 years revealed that no matter how heavy was past cocaine use most rats readily give up cocaine use in favor of the nondrug alternative. Only a minority, fewer than 15% at the heaviest level of past cocaine use, continued to take cocaine, even when hungry and offered a natural sugar that could relieve their need of calories. Conclusions/Significance This pattern of results (cocaine abstinence in most rats; cocaine preference in few rats) maps well onto the epidemiology of human cocaine addiction and suggests that only a minority of rats would be vulnerable to cocaine addiction while the large majority would be resilient despite extensive drug use. Resilience to drug addiction has long been suspected in humans but could not be firmly established, mostly because it is difficult to control retrospectively for differences in drug self-exposure and/or availability in human drug users. This conclusion has important implications for preclinical research on the neurobiology of cocaine addiction and for future medication development

  13. Thermodynamic properties of highly frustrated quantum spin ladders: Influence of many-particle bound states

    Honecker, A.; Wessel, S.; Kerkdyk, R.; Pruschke, T.; Mila, F.; Normand, B.

    2016-02-01

    Quantum antiferromagnets have proven to be some of the cleanest realizations available for theoretical, numerical, and experimental studies of quantum fluctuation effects. At finite temperatures, however, the additional effects of thermal fluctuations in the restricted phase space of a low-dimensional system have received much less attention, particularly the situation in frustrated quantum magnets, where the excitations may be complex collective (bound or even fractionalized) modes. We investigate this problem by studying the thermodynamic properties of the frustrated two-leg S =1/2 spin ladder, with particular emphasis on the fully frustrated case. We present numerical results for the magnetic specific heat and susceptibility, obtained from exact diagonalization and quantum Monte Carlo studies, which we show can be rendered free of the sign problem even in a strongly frustrated system and which allow us to reach unprecedented sizes of L =200 ladder rungs. We find that frustration effects cause an unconventional evolution of the thermodynamic response across the full parameter regime of the model. However, close to the first-order transition they cause a highly anomalous reduction in temperature scales with no concomitant changes in the gap; the specific heat shows a very narrow peak at very low energies and the susceptibility rises abruptly at extremely low temperatures. Unusually, the two quantities have different gaps over an extended region of the parameter space. We demonstrate that these results reflect the presence of large numbers of multiparticle bound-state excitations, whose energies fall below the one-triplon gap in the transition region.

  14. Thinking about going to the dentist: a Contemplation Ladder to assess dentally-avoidant individuals' readiness to go to a dentist

    Hillstead M Blake

    2011-01-01

    Full Text Available Abstract Background The Transtheoretical Model suggests that individuals vary according to their readiness to change behavior. Previous work in smoking cessation and other health areas suggests that interventions are more successful when they are tailored to an individual's stage of change with regards to the specific behavior. We report on the performance of a single-item measure ("Ladder" to assess the readiness to change dental-avoidant behavior. Methods An existing Contemplation Ladder for assessing stage of change in smoking cessation was modified to assess readiness to go to a dentist. The resulting Ladder was administered to samples of English-speaking adolescents (USA, Spanish-speaking adults (USA, and Norwegian military recruits (Norway in order to assess construct validity. The Ladder was also administered to a sample of English-speaking avoidant adolescents and young adults who were enrolled in an intervention study (USA in order to assess criterion validity. All participants also had dental examinations, and completed other questionnaires. Correlations, chi square, t tests and one-way ANOVAs were used to assess relationships between variables. Results In two samples, participants who do not go to the dentist had significantly more teeth with caries; in a third sample, participants who do not go to the dentist had significantly worse caries. Ladder scores were not significantly related to age, gender, caries, or dental fear. However, Ladder scores were significantly related to statements of intention to visit a dentist in the future and the importance of oral health. In a preliminary finding, Ladder scores at baseline also predicted whether or not the participants decided to go to a dentist in the intervention sample. Conclusions The data provide support for the convergent and divergent construct validity of the Ladder, and preliminary support for its criterion validity. The lack of relationship between dental fear and Ladder scores

  15. Plastic fish

    Antonella Del Rosso

    2015-01-01

    In terms of weight, the plastic pollution in the world’s oceans is estimated to be around 300,000 tonnes. This plastic comes from both land-based and ocean-based sources. A lecture at CERN by chemist Wolfgang Trettnak addressed this issue and highlighted the role of art in raising people’s awareness.   Artwork by Wolfgang Trettnak. Packaging materials, consumer goods (shoes, kids’ toys, etc.), leftovers from fishing and aquaculture activities… our oceans and beaches are full of plastic litter. Most of the debris from beaches is plastic bottles. “PET bottles have high durability and stability,” explains Wolfgang Trettnak, a chemist by education and artist from Austria, who gave a lecture on this topic organised by the Staff Association at CERN on 26 May. “PET degrades very slowly and the estimated lifetime of a bottle is 450 years.” In addition to the beach litter accumulated from human use, rivers bring several ki...

  16. Circuit design of Beidou satellite navigation system fishing vessels tracing instrument compatible with GPS%基于北斗导航系统并兼容GPS的渔船寻迹仪电路设计

    黄宇航; 莫盛秋; 唐龙

    2013-01-01

    In the process of the traditional fishing vessels tracing instrument positioning and tracking,it often appears defect such as tracking slow and not being easy to lock etc.,this paper puts forward the circuit design and implementation for tracking fishing traveling position trajectory instrument,it applies of domestic Beidou satellite navigation system,and is compatible with both GPS and GSM/GPRS core technology,to realize tracing and tracking of sea fishing vessels.It has the characteristics of tracing fast and tracking accurate.The results show that the positioning accuracy of tracing instrument can reach 5 m,the reacquisition time is less than 0.8 s,when the circuit power supply voltage is below 3.9 V or fishing boat speed is over 20 km/h,it will issue a warning signal.%针对传统渔船跟踪仪在定向和跟踪过程中经常出现跟踪慢和不容易锁定等缺陷,提出一种用于跟踪渔船行进位置轨迹仪的电路设计与实现方法.它应用国产北斗卫星导航系统,同时兼容GPS和GSM/GPRS核心技术,实现对出海渔船的寻迹和跟踪.得到的寻迹仪具有寻迹速度快和跟踪准确的特性.结果显示,寻迹仪的定位精度可达5 m,重捕获时间小于0.8s,当电路供电电压低于设定值或渔船航速超过设定值时,寻迹仪会自动发出报警信号.

  17. Hybrid seine for full fish community collections

    McKenna, James E.; Waldt, Emily M.; Abbett, Ross; David, Anthony; Snyder, James

    2013-01-01

    Seines are simple and effective fish collection gears, but the net mesh size influences how well the catch represents the fish communities. We designed and tested a hybrid seine with a dual-mesh bag (1/4″ and 1/8″) and compared the fish assemblage collected by each mesh. The fine-mesh net retained three times as many fish and collected more species (as many as eight), including representatives of several rare species, than did the coarser mesh. The dual-mesh bag permitted us to compare both sizes and species retained by each layer and to develop species-specific abundance correction factors, which allowed comparison of catches with the coarse-mesh seine used for earlier collections. The results indicate that a hybrid seine with coarse-mesh wings and a fine-mesh bag would enhance future studies of fish communities, especially when small-bodied fishes or early life stages are the research focus.

  18. Power stations and fish

    Some of the interactions of the CEGB's activities with aquatic life are outlined, and current research is highlighted. Fish impingement and entrainment, their significance, and the possible benefits of reducing fish ingress are discussed. The effect on fish of thermal discharges and the use of heated effluents for fish culture are considered. (author)

  19. Review of mitigation methods for fish passage, instream flows, and water quality

    This paper reports on current environmental mitigation practices at nonfederal hydropower projects. Information was obtained from project operators on dissolved oxygen (DO) mitigation, instream flows, upstream fish passage facilities, and downstream fish passage facilities. The most common method for DO mitigation is the use of spill flows, which are costly because of lost power generation. DO concentrations are commonly monitored, but biological effects of DO mitigation are not. At many projects, instream flow requirements have been set without reference to formalized methods. About half of the projects with instream flow requirements monitor flow rates, but few monitor fish populations to verify that instream flows are effective. Angled bar racks are the most commonly used downstream fish passage devices and fish ladders are the most commonly used upstream fish passage devices. Fish passage rates or populations have been monitored to verify the effectiveness of passage mitigation at few projects. This analysis is the first phase of an evaluation of the costs, benefits, and effectiveness of mitigation measures

  20. Three Kinds of Fish

    Høst, Jeppe Engset

    2012-01-01

    There are three kinds of fish. Fish you were given, fish you bought and fish you lease. This might sound a bit odd, but it is nevertheless the basis for the activities of Danish commercial fishers since the introduction of transferable fishing concessions (TFCs) in 2007. In the current 2012 reform...... of market based systems are wild speculation, concentration and monopolization of fishing access and subsequent leasing with fishing communities and new entrants very likely being worse off (see for example the chapter “From fishing rights to financial derivatives” is this volume or Olson 2011; Sumaila 2010...... will examine five Danish fishing operations and discuss how they have reacted in different ways to the newly introduced system of transferable fishing concessions. By introducing TFCs as a solution to fleet overcapacity, the EU Commission will also be introducing a system where buying, selling and leasing...

  1. Fish barriers

    In addition to literature reviews laboratory experiments with both strobe light and different kinds of sound stimuli were carried out. In the experiments silver eel, brown trout, arctic char and salmon smolts were tested. The experiments showed that in darkness silver eel avoided strobe light with intensities between 0.4 and 8.7 lux with 80-90% avoidance in 8.7 lux. The avoidance reactions decreased when background light was raised to 9 lux. Brown trout did not show as strong avoidance reactions possibly due to aggressive behaviour between different individuals of brown trout. The avoidance reaction was however more pronounced in dim background lift with an intensity of 5 lux than in darkness. The experiments also showed that the avoidance reactions started within a few seconds after exposure to strobe light. The frequencies 6.0 and 15 Hz were more effective as triggers of avoidance reactions than were the frequencies 2.1 and 160 Hz. Arctic char did not show any avoidance reactions to strobe light. It was actually attracted to strobe light with the frequency 160 Hz in total darkness and indifferent in dim background light 10 lux. Experiments in running water also showed that salmon smolts could be diverted from an area exposed to strobe light with the frequency 15.0 Hz. The effect was more pronounced in darkness than in dim background light and also more pronounced when water current was 20 cm/s than when it was 40 or 60 cm/s. Experiments to test the avoidance reactions to sound was also performed. The evaluation of these results where however complicated by the fact that the fishes swam rapidly to and fro in the experimental chamber and thus by pure chance very frequently were close to the sound generator

  2. FWS Special Designation Areas

    US Fish and Wildlife Service, Department of the Interior — This data layer depicts the Special Designations that have been placed upon the lands and waters administered by the U.S. Fish and Wildlife Service (USFWS) in North...

  3. 基于鱼群效应的多车协同行驶控制方法%An Effective Swarm Vehicle Coordinative Traffic Control Design Based on Fish Swarm Grouping Behavior

    来磊; 曲仕茹

    2012-01-01

    针对提高道路中多车行驶协同性问题,将鱼群群体行为效应引入到车辆的行驶控制中.通过对鱼群群体集群、游动行为一致性的研究,采用邻域平均法和改进的人工势场函数构造鱼群群体移动数学模型,将该移动数学模型应用到多车协同控制中,根据车辆行驶的常见运动行为,建立基于群体行为的车辆群体行驶、避障、队形变换控制方法,使行驶车辆间具有群体协同性、一致性,以提高车辆对环境的感知适应力.通过仿真实验得到的车辆行驶路径轨迹验证了该协同控制方法的有效性.%The fish swarm performs a collective movement, which is considered as a typical advanced self-organized behavior. We believe this property will increase the inter-coordination and improve the active safety for vehicles on road. Sections 1 and 2 of the full paper explain the traffic control design mentioned in the title, which we believe is effective and whose core consists of: "After analyzing the fish swarm grouping behavior, we first construct the rood-el of fish swarm behavior by an improved artificial potential function, a physical term introduced here for the purpose of collision avoidance. The artificial potential function keeps individuals suitably distant from each other; simultaneously each individual fish' s moving direction is the average of those of its neighbors, which keeps the swarm movement inter-coordinated. Then our swarm vehicle coordinative traffic control design is done with three control laws: movement, collision avoidance, and formation transformation. " The simulation results, given in Figs. 2 and 4, and the vehicle trajectory analysis show preliminarily that our swarm vehicle coordinative traffic control design is indeed effective.

  4. Community rallies to save imperiled fish

    US Fish and Wildlife Service, Department of the Interior — Newspaper article highlighting a plan for future construction of the Seven Springs Ecoscape, a park designed to protect the endangered watercress darter and educate...

  5. Why don’t adolescents eat fish? Factors influencing fish consumption in school

    Prell, Hillevi; Berg, Christina; Jonsson, Lena

    2002-01-01

    Background: Theory-based research is needed to promote healthy eating in adolescents and to work out interventions. Objective: To examine what factors influence adolescents’ fish consumption in school. Design: A total of 162 pupils from the 8th grade (age º14 years) at two schools completed a questionnaire based on the Theory of Planned Behaviour. In 150 of these subjects, fish consumption was assessed by observation on four occasions. Results: Attitudes towards the fish, friends’ behaviour a...

  6. Technologies for evaluating fish passage through turbines

    Weiland, Mark A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Carlson, Thomas J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2003-10-01

    This study evaluated the feasibility of two types of technologies to observe fish and near neutrally buoyant drogues as they move through hydropower turbines. Existing or reasonably modified light-emitting and ultrasonic technologies were used to observe flow patterns, the response of fish to flow, and interactions between fish and turbine structures with good spatial and temporal accuracy. This information can be used to assess the biological benefits of turbine design features such as reductions in gaps at the tips and hub of turbine runner blades, reshaping wicket gates and stay vanes, modifications to draft tube splitter piers, and design changes that enhance egress through the powerhouse and tailrace.

  7. A ladder network modelling the electrochemical impedance of the diffusion and reaction processes in semi-infinite space.

    Moya, A A

    2016-02-01

    The Gerischer impedance, i.e., the diffusion-reaction impedance of an ionic species in semi-infinite space, has been modelled by means of a novel simple equivalent ladder electric circuit constituted by a finite number of resistors and capacitors, which corresponds to the Cauer structure obtained from development into continued fractions. The Nyquist plots of the impedance of the ladder network or Cauer circuit and the deviation with respect to the Gerischer impedance have been originally analysed as a function of the number of circuit elements. From the Cauer equivalent circuit, a new and simple expression modelling the Gerischer impedance at the limit of the lowest frequencies has been derived. PMID:26763107

  8. Walking on the Ladder: 125 GeV Technidilaton, or Conformal Higgs -Dedicated to the late Professor Yoichiro Nambu-

    Matsuzaki, Shinya

    2015-01-01

    The walking technicolor based on the ladder Schwinger-Dyson gap equation is studied, with the scale-invariant coupling being an idealization of the Caswell-Banks-Zaks infrared fixed point in the "anti-Veneziano limit", such that $N_C \\rightarrow \\infty$ with $N_C \\cdot \\alpha(\\mu^2)=$ fixed and $N_F/N_C=$ fixed ($\\gg 1$), of the $SU(N_C)$ gauge theory with massless $N_F$ flavors near criticality. We show that the 125 GeV Higgs can be naturally identified with the technidilaton (TD) predicted in the walking technicolor, a pseudo Nambu-Goldstone (NG) boson of the spontaneous symmetry breaking of the approximate scale symmetry. Ladder calculations yield the TD mass $M_\\phi$ from the trace anomaly as $M_\\phi^2 F_\\phi^2= -4 \\langle \\theta_\\mu^\\mu \\rangle = - \\frac{\\beta(\\alpha (\\mu^2))}{\\alpha(\\mu^2)}\\, \\langle G_{\\lambda \

  9. Superconductivity on a Crossover Phenomenon of Spin-Ladder System SrCa13Cu24O41 Single Crystals

    Hisada, Akihiko; Matsubayashi, Kazuyuki; Uwatoko, Yoshiya; Fujiwara, Naoki; Deng, Guochu; Pomjakushina, Ekaterina; Conder, Kazimierz; Mohan Radheep, Dinadhayalane; Thiyagarajan, Raman; Esakkimuthu, Sankaran; Arumugam, Sonachalam

    2014-07-01

    Electrical resistivity and alternating current susceptibility measurements were performed for the spin-ladder compound SrCa13Cu24O41 under hydrostatic pressure up to 8 GPa. The superconducting transition was observed below TC = 14.7 K at pressures above 2 GPa. By using high-quality single crystals, the bulk superconductivity with a volume fraction of 50% and temperature quadratic behavior of the normal state resistivity were observed above 3.7 GPa. They suggest that a strong interladder interaction induces the bulk superconductivity and transforms the system into a Fermi-liquid-like state. The optimal pressure was in a crossover region and the highest TC was observed without going through the bulk superconducting state. Our results suggest that the superconducting state on the crossover phenomenon presents the feature of the doped two-leg spin-ladder system because the spin gap was observed in this compound.

  10. Star formation relations and CO spectral line energy distributions across the J-ladder and redshift

    Greve, T. R. [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Leonidaki, I.; Xilouris, E. M. [Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing, National Observatory of Athens, GR-15236 Penteli (Greece); Weiß, A.; Henkel, C. [Max-Planck-Institut fur Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Zhang, Z.-Y. [UK Astronomy Technology Centre, Science and Technology Facilities Council, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Van der Werf, P.; Meijerink, R. [Leiden Observatory, Leiden University, PO Box 9513, NL-2300 RA Leiden (Netherlands); Aalto, S. [Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Observatory, 43994 Onsala (Sweden); Armus, L.; Díaz-Santos, T. [Spitzer Science Center, California Institute of Technology, MS 220-6, Pasadena, CA 91125 (United States); Evans, A. S. [Astronomy Department, University of Virginia Charlottesville, VA 22904 (United States); Fischer, J. [Naval Research Laboratory, Remote Sensing Division, 4555 Overlook Avenue SW, Washington, DC 20375 (United States); Gao, Y. [Purple Mountain Observatory, Chinese Academy of Sciences, 2 West Beijing Road, Nanjing 210008 (China); González-Alfonso, E. [Universidad de Alcala de Henares, Departamento de Fśica, Campus Universitario, E-28871 Alcalá de Henares, Madrid (Spain); Harris, A. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Naylor, D. A. [Institute for Space Imaging Science, Department of Physics and Astronomy, University of Lethbridge, Lethbridge, AB T1K 3M4 (Canada); Smith, H. A. [Harvard Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Spaans, M., E-mail: t.greve@ucl.ac.uk [Kapteyn Astronomical Institute, University of Groningen, PO Box 800, 9700 AV Groningen (Netherlands); and others

    2014-10-20

    We present FIR [50-300 μm]–CO luminosity relations (i.e., log L{sub FIR}=αlog L{sub CO}{sup ′}+β) for the full CO rotational ladder from J = 1-0 up to J = 13-12 for a sample of 62 local (z ≤ 0.1) (Ultra) Luminous Infrared Galaxies (LIRGs; L {sub IR[8-1000} {sub μm]} > 10{sup 11} L {sub ☉}) using data from Herschel SPIRE-FTS and ground-based telescopes. We extend our sample to high redshifts (z > 1) by including 35 submillimeter selected dusty star forming galaxies from the literature with robust CO observations, and sufficiently well-sampled FIR/submillimeter spectral energy distributions (SEDs), so that accurate FIR luminosities can be determined. The addition of luminous starbursts at high redshifts enlarge the range of the FIR–CO luminosity relations toward the high-IR-luminosity end, while also significantly increasing the small amount of mid-J/high-J CO line data (J = 5-4 and higher) that was available prior to Herschel. This new data set (both in terms of IR luminosity and J-ladder) reveals linear FIR–CO luminosity relations (i.e., α ≅ 1) for J = 1-0 up to J = 5-4, with a nearly constant normalization (β ∼ 2). In the simplest physical scenario, this is expected from the (also) linear FIR–(molecular line) relations recently found for the dense gas tracer lines (HCN and CS), as long as the dense gas mass fraction does not vary strongly within our (merger/starburst)-dominated sample. However, from J = 6-5 and up to the J = 13-12 transition, we find an increasingly sublinear slope and higher normalization constant with increasing J. We argue that these are caused by a warm (∼100 K) and dense (>10{sup 4} cm{sup –3}) gas component whose thermal state is unlikely to be maintained by star-formation-powered far-UV radiation fields (and thus is no longer directly tied to the star formation rate). We suggest that mechanical heating (e.g., supernova-driven turbulence and shocks), and not cosmic rays, is the more likely source of energy for

  11. Synthesis and characterization of polyimide copolymers containing ladder-like polysiloxane

    Feng, Linqian

    This research is focused on the synthesis, development, analysis and evaluation of properties of polyurea-b-polyimide (PUI) copolymers containing ladder-like polysiloxane. PUI block copolymers were successfully synthesized by condensation polymerization methods. The structure and properties of the copolymers were controlled by controlling the (i) co-monomer concentration and (ii) curing temperature. Thermally controlled self-assembly of semi-crystalline copolymers occurred at higher annealing temperatures T ≥ 150°C, resulting in remarkable enhancement in their thermomechanical properties. The observed improvement in the structure and mechanical properties of the copolymers annealed at higher temperature is believed to be due to the development of inter and intra-hydrogen bonding interactions between adjacent copolymer chains. The dynamic mechanical property of the copolymers was determined by dynamic mechanical analysis (DMA) using solution cast thin films. Fourier transform infrared spectroscopy, FTIR and Wide angle X-ray diffraction (WAXD) method were used to study the composition and structure of the copolymers. The presence of hydrogen-bonded (H-bonded) polyimide units in the copolymer resulted in a significant enhancement in the corrosion protection of aluminum alloy 2024-T3. The corrosion performance of PUI coatings was studied by direct current polarization method (DCP) and electrochemical impedance spectroscopy (EIS) in a 3.5wt% NaCl solution. Corrosion performance was remarkably increased by increasing (i) polyurea concentration and (ii) annealing temperature. The coating lifetime was evaluated by using information from time-based Bode plot as well as gravimetric weight gain analysis. The surface energy and diffusivity of PUI copolymers were remarkably decreased as polyurea concentration increased. Semi-crystalline ladder-like polysiloxanes (LPS) containing both mercapto and fluoride side groups were synthesized by using both the sol-gel and monomer

  12. Walking on the ladder: 125 GeV technidilaton, or Conformal Higgs

    Matsuzaki, Shinya; Yamawaki, Koichi

    2015-12-01

    The walking technicolor based on the ladder Schwinger-Dyson gap equation is studied, with the scale-invariant coupling being an idealization of the Caswell-Banks-Zaks infrared fixed point in the "anti-Veneziano limit", such that N C → ∞ with N C · α( μ 2) = fixed and N F / N C = fixed (≫1), of the SU( N C ) gauge theory with massless N F flavors near criticality. We show that the 125 GeV Higgs can be naturally identified with the technidilaton (TD) predicted in the walking technicolor, a pseudo Nambu-Goldstone (NG) boson of the spontaneous symmetry breaking of the approximate scale symmetry. Ladder calculations yield the TD mass M ϕ from the trace anomaly as {M}_{φ}^2{F}_{φ}^2=-4 =-β (α ({μ}^2))/α ({μ^2)} ˜eq {N}_C{N}_F16/π^4{m}_F^4 , independently of the renormalization point μ, where m F is the dynamical mass of the technifermion, and {F}_{φ }=O(√{N_F{N}_C}{m}_F) the TD decay constant. It reads {M}_{φ}^2˜eq {(\\upsilon_{EW}/2\\cdot 5{\\upsilon}_{EW}/F_{φ })}^2\\cdot [8/N_F4/N_C],({\\upsilon}_{EW}=246GeV) , which implies F ϕ ≃ 5 v EW for M ϕ ≃ 125 GeV ≃ 1/2 v EW in the one-family model ( N C = 4 , N F = 8), in good agreement with the current LHC Higgs data. The result reflects a generic scaling M ϕ 2 / υ EW 2 ˜ M ϕ 2 / F ϕ 2 ˜ m F 2 / F ϕ 2 ˜ 1/( N F N C ) → 0 as a vanishing trace anomaly, namely the TD has a mass vanishing in the anti-Veneziano limit, similarly to η' meson as a pseudo-NG boson of the ordinary QCD with vanishing U(1) A anomaly in the Veneziano limit ( N F / N C ≪ 1).

  13. Star formation relations and CO spectral line energy distributions across the J-ladder and redshift

    We present FIR [50-300 μm]–CO luminosity relations (i.e., log LFIR=αlog LCO′+β) for the full CO rotational ladder from J = 1-0 up to J = 13-12 for a sample of 62 local (z ≤ 0.1) (Ultra) Luminous Infrared Galaxies (LIRGs; L IR[8-1000 μm] > 1011 L ☉) using data from Herschel SPIRE-FTS and ground-based telescopes. We extend our sample to high redshifts (z > 1) by including 35 submillimeter selected dusty star forming galaxies from the literature with robust CO observations, and sufficiently well-sampled FIR/submillimeter spectral energy distributions (SEDs), so that accurate FIR luminosities can be determined. The addition of luminous starbursts at high redshifts enlarge the range of the FIR–CO luminosity relations toward the high-IR-luminosity end, while also significantly increasing the small amount of mid-J/high-J CO line data (J = 5-4 and higher) that was available prior to Herschel. This new data set (both in terms of IR luminosity and J-ladder) reveals linear FIR–CO luminosity relations (i.e., α ≅ 1) for J = 1-0 up to J = 5-4, with a nearly constant normalization (β ∼ 2). In the simplest physical scenario, this is expected from the (also) linear FIR–(molecular line) relations recently found for the dense gas tracer lines (HCN and CS), as long as the dense gas mass fraction does not vary strongly within our (merger/starburst)-dominated sample. However, from J = 6-5 and up to the J = 13-12 transition, we find an increasingly sublinear slope and higher normalization constant with increasing J. We argue that these are caused by a warm (∼100 K) and dense (>104 cm–3) gas component whose thermal state is unlikely to be maintained by star-formation-powered far-UV radiation fields (and thus is no longer directly tied to the star formation rate). We suggest that mechanical heating (e.g., supernova-driven turbulence and shocks), and not cosmic rays, is the more likely source of energy for this component. The global CO spectral line energy

  14. A REDETERMINATION OF THE HUBBLE CONSTANT WITH THE HUBBLE SPACE TELESCOPE FROM A DIFFERENTIAL DISTANCE LADDER

    This is the second of two papers reporting results from a program to determine the Hubble constant to ∼5% precision from a refurbished distance ladder based on extensive use of differential measurements. Here we report observations of 240 Cepheid variables obtained with the Near-Infrared Camera and Multi-Object Spectrometer (NICMOS) Camera 2 through the F160W filter on the Hubble Space Telescope (HST). The Cepheids are distributed across six recent hosts of Type Ia supernovae (SNe Ia) and the 'maser galaxy' NGC 4258, allowing us to directly calibrate the peak luminosities of the SNe Ia from the precise, geometric distance measurements provided by the masers. New features of our measurement include the use of the same instrument for all Cepheid measurements across the distance ladder and homogeneity of the Cepheid periods and metallicities, thus necessitating only a differential measurement of Cepheid fluxes and reducing the largest systematic uncertainties in the determination of the fiducial SN Ia luminosity. In addition, the NICMOS measurements reduce the effects of differential extinction in the host galaxies by a factor of ∼5 over past optical data. Combined with a greatly expanded set of 240 SNe Ia at z 0 = 74.2 ± 3.6 km s-1 Mpc-1, a 4.8% uncertainty including both statistical and systematic errors. To independently test the maser calibration, we use 10 individual parallax measurements of Galactic Cepheids obtained with the HST fine guidance sensor and find similar results. We show that the factor of 2.2 improvement in the precision of H 0 is a significant aid to the determination of the equation-of-state parameter of dark energy, w = P/(ρc2). Combined with the Wilkinson Microwave Anisotropy Probe five-year measurement of ΩM h2, we find w = -1.12 ± 0.12 independent of any information from high-redshift SNe Ia or baryon acoustic oscillations (BAO). This result is also consistent with analyses based on the combination of high-redshift SNe Ia and BAO. The

  15. Quantum melting of the hole crystal in the spin ladder of Sr14-xCaxCu24O41

    Rusydi, A.; Abbamonte, P.; Eisaki, H.; Fujimaki, Y.; Blumberg, G.; Uchida, S.; Sawatzky, G. A.

    2006-01-01

    We have used resonant soft x-ray scattering to study the effects of discommensuration on the hole Wigner crystal (HC) in the spin ladder Sr14-xCaxCu24O41 (SCCO). As the hole density is varied the HC forms only with the commensurate wave vectors L-L=1/5 and L-L=1/3; for incommensurate values it "melt

  16. Universality class of an S=(1/2) quantum spin ladder system with four-spin exchange

    We study a s=(1/2) Heisenberg spin ladder with four-spin exchange. Combining numerical results with conformal field theory, we find a phase transition with central charge c=(3/2). Since this system has an SU(2) symmetry, we can conclude that this critical theory is described by k=2 SU(2) Wess-Zumino-Witten model with Z2 symmetry breaking

  17. Implementation of Evidence-Based Practice in Relation to a Clinical Nursing Ladder System: A National Survey in Taiwan

    Weng, Yi-Hao; Chen, Chiehfeng; Kuo, Ken N; Yang, Chun-Yuh; Lo, Heng-Lien; Chen, Kee-Hsin; Chiu, Ya-Wen

    2015-01-01

    Background Although evidence-based practice (EBP) has been widely investigated, few studies have investigated its correlation with a clinical nursing ladder system. The current national study evaluates whether EBP implementation has been incorporated into the clinical ladder system. Methods A cross-sectional questionnaire survey was conducted nationwide of registered nurses among regional hospitals of Taiwan in January to April 2011. Subjects were categorized into beginning nurses (N1 and N2) and advanced nurses (N3 and N4) by the clinical ladder system. Multivariate logistic regression model was used to adjust for possible confounding demographic factors. Results Valid postal questionnaires were collected from 4,206 nurses, including 2,028 N1, 1,595 N2, 412 N3, and 171 N4 nurses. Advanced nurses were more aware of EBP than beginning nurses (p < 0.001; 90.7% vs. 78.0%). In addition, advanced nurses were more likely to hold positive beliefs about and attitudes toward EBP (p < 0.001) and possessed more sufficient knowledge of and skills in EBP (p < 0.001). Furthermore, they more often implemented EBP principles (p < 0.001) and accessed online evidence-based retrieval databases (p < 0.001). The most common motivation for using online databases was self-learning for advanced nurses and positional promotion for beginning nurses. Multivariate logistic regression analyses showed advanced nurses were more aware of EBP, had higher knowledge and skills of EBP, and more often implemented EBP than beginning nurses. Linking Evidence to Action The awareness of, beliefs in, attitudes toward, knowledge of, skills in, and behaviors of EBP among advanced nurses were better than those among beginning nurses. The data indicate that a clinical ladder system can serve as a useful means to enhance EBP implementation. PMID:25588625

  18. Incorporating e-learning into a Local Government Authority Context: Evaluating Developers' Perspectives on the Learning Ladder Project

    Smith, Christine; Zenios, Maria

    2006-01-01

    In this paper, we describe the evaluation of an e-learning project. The Learning Ladder developed a number of elearning modules for local government staff on recurrent working practices. The modules feature the use of short video clips as a means to support and encourage organisational learning. We report on one part of the evaluation: namely, the qualitative analysis of data from developers. We focus on three aspects: developers' perceptions of video clips for learners to reflect upon exampl...

  19. Two-step Doppler cooling of a three-level ladder system with an intermediate metastable level

    Champenois, Caroline; Hagel, Gaetan; Knoop, Martina; Houssin, Marie; Zumsteg, Cedric; Vedel, Fernande; Drewsen, Michael

    2007-01-01

    Doppler laser cooling of a three-level ladder system using two near-resonant laser fields is analyzed in the case of the intermediate level being metastable while the upper level is short-lived. Analytical as well as numerical results for e.g. obtainable scattering rates and achievable temperatures are presented. When appropriate, comparisons with two-level single photon Doppler laser cooling is made. These results are relevant to recent experimental Doppler laser cooling investigations addre...

  20. Consumer beliefs regarding farmed versus wild fish.

    Claret, Anna; Guerrero, Luis; Ginés, Rafael; Grau, Amàlia; Hernández, M Dolores; Aguirre, Enaitz; Peleteiro, José Benito; Fernández-Pato, Carlos; Rodríguez-Rodríguez, Carmen

    2014-08-01

    Aquaculture is a food-producing activity, alternative to traditional extractive fishing, which still acts as a reference for most consumers. The main objective of the present paper was to study which consumer beliefs, regarding farmed versus wild fish, hinder the potential development of the aquaculture sector. To achieve this purpose the study was organized into two complementary steps: a qualitative approach (focus groups) aimed at assessing consumer perception about wild and farmed fish and to identify the salient beliefs that differentiate them; and a quantitative approach (survey by means of a questionnaire) to validate the results obtained in the focus group discussions over a representative sample of participants (n = 919). Results showed that participants perceive clear differences between farmed and wild fish. Although no significant differences between both kinds of fish were detected on safety, in general farmed fish was perceived to be less affected by marine pollution, heavy metals and parasites. In the contrary, wild fish was considered to have healthier feeding, to contain fewer antibiotics and to be fresher, healthier, less handled and more natural. Beliefs related to quality were in favour of wild fish, while those related to availability and price were in favour of farmed fish. Significant differences were observed in the perception of both kinds of fish depending on the consumers' objective knowledge about fish, on the level of education, age and gender and on the three segments of consumers identified: "Traditional/Conservative", "Connoisseur", "Open to aquaculture". The results provided could play an important role when planning and designing efficient marketing strategies for promoting farmed fish by adapting the information provided to the perception of each segment of consumers identified by the present study. PMID:24709486

  1. Quantum Monte Carlo simulation of antiferromagnetic spin ladder (C5H12N)2CuBr4

    Freitas, Augusto S.

    2016-07-01

    In this paper I present a Quantum Monte Carlo (QMC) study of the magnetic properties of an antiferromagnetic spin ladder (C5H12N)2CuBr4. This compound is the prototype of the Heisenberg model for a two leg spin ladder in the presence of an external magnetic field. The susceptibility phase diagram has a rounded peak in the vicinity of T=7.4 K, obeys Troyer's law for low temperatures, and Curie's law for high temperatures. I also study the susceptibility diagram in low temperatures and I found the spin gap Δ=9.26 K, in good concordance with the experimental value, 9.5 K. In high field, I present a diagram of magnetization as a function of temperature. In the vicinity of a critical field, Hci, the magnetization scales with T1/2 and this result was found also in the QMC simulation. In all the results, there is a very good concordance with the experimental data. I also show in this paper that the spin gap is null and the susceptibility is proportional to T for low temperatures when relatively high values of the ladders' coupling is taken in account.

  2. Environmental mitigation at hydroelectric projects. Volume 2, Benefits and costs of fish passage and protection

    Francfort, J.E.; Rinehart, B.N.; Sommers, G.L. [EG and G Idaho, Inc., Idaho Falls, ID (United States); Cada, G.F.; Jones, D.W. [Oak Ridge National Lab., TN (United States); Dauble, D.D. [Pacific Northwest Lab., Richland, WA (United States); Hunt, R.T. [Hunt (Richard) Associates, Inc., Concord, NH (United States); Costello, R.J. [Northwest Water Resources Advisory Services (United States)

    1994-01-01

    This study examines envirorunental mitigation practices that provide upstream and downstream fish passage and protection at hydroelectric projects. The study includes a survey of fish passage and protection mitigation practices at 1,825 hydroelectric plants regulated by the Federal Energy Regulatory Commission (FERC) to determine frequencies of occurrence, temporal trends, and regional practices based on FERC regions. The study also describes, in general terms, the fish passage/protection mitigation costs at 50 non-Federal hydroelectric projects. Sixteen case studies are used to examine in detail the benefits and costs of fish passage and protection. The 16 case studies include 15 FERC licensed or exempted hydroelectric projects and one Federally-owned and-operated hydroelectric project. The 16 hydroelectric projects are located in 12 states and range in capacity from 400 kilowatts to 840 megawatts. The fish passage and protection mitigation methods at the case studies include fish ladders and lifts, an Eicher screen, spill flows, airburst-cleaned inclined and cylindrical wedgewire screens, vertical barrier screens, and submerged traveling screens. The costs, benefits, monitoring methods, and operating characteristics of these and other mitigation methods used at the 16 case studies are examined.

  3. Laboratory Studies on the Effects of Shear on Fish

    Neitzel, Duane A.; Richmond, Marshall C.; Dauble, Dennis D.; Mueller, Robert P.; Moursund, Russell A.; Abernethy, Cary S.; Guensch, Greg R.

    2000-09-20

    The overall objective of our studies was to specify an index describing the hydraulic force that fish experience when subjected to a shear environment. Fluid shear is a phenomenon that is important to fish. However, elevated levels of shear may result in strain rates that injure or kill fish. At hydroelectric generating facilities, concerns have been expressed that strain rates associated with passage through turbines, spillways, and fish bypass systems may adversely affect migrating fish. Development of fish friendly hydroelectric turbines requires knowledge of the physical forces (injury mechanisms) that impact entrained fish and the fish's tolerance to these forces. It requires up-front, pre-design specifications for the environmental conditions that occur within the turbine system, in other words, determining or assuming that those conditions known to injure fish will provide the descriptions of conditions that engineers must consider in the design of a turbine system. These biological specifications must be carefully and thoroughly documented throughout the design of a fish friendly turbine. To address the development of biological specifications, we designed and built a test facility where juvenile fish could be subjected to a range of shear environments and quantified their biological response.

  4. Automated Translation of Safety Critical Application Software Specifications into PLC Ladder Logic

    Leucht, Kurt W.; Semmel, Glenn S.

    2008-01-01

    The numerous benefits of automatic application code generation are widely accepted within the software engineering community. A few of these benefits include raising the abstraction level of application programming, shorter product development time, lower maintenance costs, and increased code quality and consistency. Surprisingly, code generation concepts have not yet found wide acceptance and use in the field of programmable logic controller (PLC) software development. Software engineers at the NASA Kennedy Space Center (KSC) recognized the need for PLC code generation while developing their new ground checkout and launch processing system. They developed a process and a prototype software tool that automatically translates a high-level representation or specification of safety critical application software into ladder logic that executes on a PLC. This process and tool are expected to increase the reliability of the PLC code over that which is written manually, and may even lower life-cycle costs and shorten the development schedule of the new control system at KSC. This paper examines the problem domain and discusses the process and software tool that were prototyped by the KSC software engineers.

  5. Four electrons in a two-leg Hubbard ladder: exact ground states

    In the case of a two-leg Hubbard ladder we present a procedure which allows the exact deduction of the ground state for the four-particle problem in an arbitrary large lattice system, in a tractable manner, which involves only a reduced Hilbert space region containing the ground state. In the presented case, the method leads to nine analytic, linear and coupled equations providing the ground state. The procedure which is also applicable to few particle problems and other systems is based on an r-space representation of the wavefunctions and construction of symmetry adapted orthogonal basis wave vectors describing the Hilbert space region containing the ground state. Once the ground state is deduced, a complete quantum-mechanical characterization of the studied state can be given. Since the analytic structure of the ground state becomes visible during the use of the method, it is important not only to the understanding of theoretical aspects connected to exact descriptions or potential numerical approximation scheme developments, but is also relevant for a large number of potential technological application possibilities placed between nano-devices and quantum calculations, where the few particle behaviour and deep understanding are important key aspects

  6. Wire and extended ladder model predict THz oscillations in DNA monomers, dimers and trimers

    Lambropoulos, K; Morphis, A; Tassi, M; Lopp, R; Georgiadis, G; Theodorakou, M; Chatzieleftheriou, M; Simserides, C

    2016-01-01

    We call \\textit{monomer} a B-DNA base pair and study, analytically and numerically, electron or hole oscillations in \\textit{monomers}, \\textit{dimers} and \\textit{trimers}. We employ two Tight Binding (TB) approaches: (I) at the base-pair level, using the on-site energies of the base pairs and the hopping parameters between successive base pairs i.e. \\textit{a wire model}, and (II) at the single-base level, using the on-site energies of the bases and the hopping parameters between neighbouring bases, specifically between (a) two successive bases in the same strand, (b) complementary bases that define a base pair, and (c) diagonally located bases of successive base pairs, i.e. \\textit{an extended ladder model} since it also includes the diagonal hoppings (c). For \\textit{monomers}, with TB II, we predict periodic carrier oscillations with frequency $f \\approx$ 50-550 THz. For \\textit{dimers}, with TB I, we predict periodic carrier oscillations with $f \\approx$ 0.25-100 THz. For \\textit{trimers made of identic...

  7. Effects of relative phase on transient evolution in an open resonant ladder-type atomic system

    Yang Yan-Ling; Liu Zhong-Bo; Wang Lei; Tong Dian-Min; Fan Xi-Jun

    2009-01-01

    In an open ladder-type resonant atomic system, variation in relative phase between probe and driving fields does not affect the transient evolution of populations, but it has remarkable effects on gain and dispersion of the probe field. No matter whether an incoherent pump is present or absent, transient and stationary gains without inversion (GWI) always can be obtained by choosing an appropriate value of the relative phase. When the incoherent pump is absent, the values of transient and stationary GWIs are much larger and the time interval required to reach the stationary value is longer than those when the incoherent pump is present. Varying the exit rate and the ratio between injection rates can obviously change the phase-dependent GWI. In addition, in the transient evolution process, the phenomenon of high dispersion (refractive index) without absorption occurs at some values of relative phase. In the corresponding closed system, the stationary GWI can be obtained by choosing an appropriate value of relative phase only when incoherent pump exists, moreover the gain is smaller than that in the open system.

  8. Calculating three loop ladder and V-topologies for massive operator matrix elements by computer algebra

    Three loop ladder and V-topology diagrams contributing to the massive operator matrix element AQg are calculated. The corresponding objects can all be expressed in terms of nested sums and recurrences depending on the Mellin variable N and the dimensional parameter ε. Given these representations, the desired Laurent series expansions in ε can be obtained with the help of our computer algebra toolbox. Here we rely on generalized hypergeometric functions and Mellin-Barnes representations, on difference ring algorithms for symbolic summation, on an optimized version of the multivariate Almkvist-Zeilberger algorithm for symbolic integration, and on new methods to calculate Laurent series solutions of coupled systems of differential equations. The solutions can be computed for general coefficient matrices directly for any basis also performing the expansion in the dimensional parameter in case it is expressible in terms of indefinite nested product-sum expressions. This structural result is based on new results of our difference ring theory. In the cases discussed we deal with iterative sum- and integral-solutions over general alphabets. The final results are expressed in terms of special sums, forming quasi-shuffle algebras, such as nested harmonic sums, generalized harmonic sums, and nested binomially weighted (cyclotomic) sums. Analytic continuations to complex values of N are possible through the recursion relations obeyed by these quantities and their analytic asymptotic expansions. The latter lead to a host of new constants beyond the multiple zeta values, the infinite generalized harmonic and cyclotomic sums in the case of V-topologies.

  9. Disorder effects in the S=1 antiferromagnetic spin ladder CaV2O4

    Guitarra, S. R.; Caneiro, A.; Niebieskikwiat, D.

    2015-10-01

    We study the physical properties of the antiferromagnetic spin ladder CaV2O4 (CVO) and the Y-doped related compound Ca0.9Y0.1V2O4. In the latter, X-ray diffraction demonstrates the segregation of a small amount of a vanadium-perovskite impurity phase, leading to the formation of V vacancies within the main CVO-type structure. The 1D character of this calcium-vanadite enhances the influence of the vacancies on the electric and magnetic properties of Ca0.9Y0.1V2O4. Electrical transport is characterized by a variable-range hopping mechanism determined by the charging energy of nm-sized segments of V chains delimited by V vacancies, i.e. a Coulomb gap is formed at the Fermi level. These vacancies also locally affect the magnetic correlations, breaking the long-range AFM order observed in CaV2O4 and producing exchange bias when the Y-doped sample is cooled with an applied magnetic field.

  10. Calculating three loop ladder and V-topologies for massive operator matrix elements by computer algebra

    Ablinger, J.; Behring, A.; Blümlein, J.; De Freitas, A.; von Manteuffel, A.; Schneider, C.

    2016-05-01

    Three loop ladder and V-topology diagrams contributing to the massive operator matrix element AQg are calculated. The corresponding objects can all be expressed in terms of nested sums and recurrences depending on the Mellin variable N and the dimensional parameter ε. Given these representations, the desired Laurent series expansions in ε can be obtained with the help of our computer algebra toolbox. Here we rely on generalized hypergeometric functions and Mellin-Barnes representations, on difference ring algorithms for symbolic summation, on an optimized version of the multivariate Almkvist-Zeilberger algorithm for symbolic integration, and on new methods to calculate Laurent series solutions of coupled systems of differential equations. The solutions can be computed for general coefficient matrices directly for any basis also performing the expansion in the dimensional parameter in case it is expressible in terms of indefinite nested product-sum expressions. This structural result is based on new results of our difference ring theory. In the cases discussed we deal with iterative sum- and integral-solutions over general alphabets. The final results are expressed in terms of special sums, forming quasi-shuffle algebras, such as nested harmonic sums, generalized harmonic sums, and nested binomially weighted (cyclotomic) sums. Analytic continuations to complex values of N are possible through the recursion relations obeyed by these quantities and their analytic asymptotic expansions. The latter lead to a host of new constants beyond the multiple zeta values, the infinite generalized harmonic and cyclotomic sums in the case of V-topologies.

  11. On the cusp anomalous dimension in the ladder limit of $\\mathcal N=4$ SYM

    Beccaria, Matteo; Macorini, Guido

    2016-01-01

    We analyze the cusp anomalous dimension in the (leading) ladder limit of $\\mathcal N=4$ SYM and present new results for its higher-order perturbative expansion. We study two different limits with respect to the cusp angle $\\phi$. The first is the light-like regime where $x = e^{i\\,\\phi}\\to 0$. This limit is characterised by a non-trivial expansion of the cusp anomaly as a sum of powers of $\\log x$, where the maximum exponent increases with the loop order. The coefficients of this expansion have remarkable transcendentality features and can be expressed by products of single zeta values. We show that the whole logarithmic expansion is fully captured by a solvable Woods-Saxon like one-dimensional potential. From the exact solution, we extract generating functions for the cusp anomaly as well as for the various specific transcendental structures appearing therein. The second limit that we discuss is the regime of small cusp angle. In this somewhat simpler case, we show how to organise the quantum mechanical pert...

  12. Coherent manipulation of absorption by intense fields in four level ladder system

    Kumar, Pardeep; Dasgupta, Shubhrangshu

    2016-05-01

    Nonlinear optical processes attributed to the dependence of the susceptibility of the medium on the input fluence can be remarkably manipulated by the quantum interference and coherence. One of these processes, the optical bistability (OB), that refers to the possibilities of two stable outputs for the same input fields, can also be modified by quantum coherence. Further, the nonlinear dependence of the absorption on the power of the input light gives rise to interesting processes like saturable absorption (SA) and reverse saturable absorption (RSA). While the SA corresponds to the decrease in the absorption coefficient with the increase of intensity of input light, the RSA corresponds to otherwise, that finds applications in optical limiting. We show, using a four-level Ladder system, how a control field manipulates these processes for an intense probe field applied in the excited state transition. The nonlinear absorption increases whereas the threshold of OB decreases in presence of a control field. We further delineates how the control field and the decay rates modifies SA and RSA. The control of these processes find applications in optical switching, optical limiting and optical communications.

  13. Transport properties of poly(GACT)–poly(CTGA) deoxyribonucleic acid: A ladder model approach

    S A Ketabi; A A Fouladi

    2009-06-01

    In this paper, based on the tight-binding Hamiltonian model and within the framework of a generalized Green's function technique, the electronic conduction through the poly(GACT)–poly(CTGA) DNA molecule in SWNT/DNA/SWNT structure has been numerically investigated. In a ladder model, we consider DNA as a planar molecule containing cells and four further sites (two base pair sites and two backbone sites) in each cell, sandwiched between two semi-infinite single-walled carbon nanotubes (SWNT) as the electrodes. Having relied on Landauer formalism, we focussed on studying the current–voltage characteristics of DNA, the effect of the coupling strength of SWNT/DNA interface and the role of tube radius of nanotube contacts on the electronic transmission through the foregoing structure. Finally, a characteristic time was calculated for the electron transmission, which measures the delay caused by the tunnelling through the SWNT/DNA interface. The results clearly show that the calculated characteristic time and also the conductance of the system are sensitive to the coupling strength between DNA molecule and nanotube contacts.

  14. Integrable nonlinear ladder system with background-controlled intersite resonant coupling

    A new spectral problem on one-dimensional lattices is found allowing consistently to support the zero-curvature representation for a wide class of integrable nonlinear ladder systems. The modified recurrence technique for obtaining an infinite set of conservation laws is developed and some basic conserved quantities are explicitly derived. The eigenvalue problems associated with the limiting spectral operator for the special case of rapidly vanishing boundary conditions on Schroedinger-type fields and finite background condition on a concomitant field are solved and the domains of analyticity of Jost functions are presented both analytically and graphically. This particular example shows that the original auxiliary spectral problem is basically of fourth order and must generate a set of four distinct Jost functions that have to be involved in the procedure of inverse scattering transform. Moreover, there exists a critical background value of accompanying field which separates two principally different possibilities in the organization of analyticity domains of Jost functions. This crossover should inevitably lead to qualitative rearrangements in the structure of model solutions. Thus already in the limit of low-amplitude excitations we strictly observe the loss of stability regarding the linear spectrum of Schroedinger subsystem just above the critical background value of practically unexcited concomitant field, whereas in the stability region the structure of linear spectrum is essentially controlled by the magnitude of background level via effective modification of both intersite resonant coupling and self-site coupling

  15. Poisoning - fish and shellfish

    Fish poisoning; Dinoflagellate poisoning; Seafood contamination; Paralytic shellfish poisoning; Ciguatera poisoning ... algae and algae-like organisms called dinoflagellates. Small fish that eat the algae become contaminated. If larger ...

  16. Scorpion fish sting

    ... page: //medlineplus.gov/ency/article/002849.htm Scorpion fish sting To use the sharing features on this page, please enable JavaScript. Scorpion fish are members of the family Scorpaenidae, which includes ...

  17. Compatibility Determination : Recreational Fishing

    US Fish and Wildlife Service, Department of the Interior — It is determined in this document that recreational fishing of bass and brim on St. Vincent National Wildlife Refuge is consistent with Refuge Objectives. The...

  18. Umatilla - Rough Fish Eradication

    US Fish and Wildlife Service, Department of the Interior — In order to enhance environmental conditions in the McCormack Slough on Umatilla NWR, the population of rough fish, including common carp (Cyprinus carpio) and...

  19. Alaskan sport fishing waters

    US Fish and Wildlife Service, Department of the Interior — As a guide to newcomers and visitors, fishery biologists have compiled a list of some of the well-known fishing waters in Alaska. The list is merely a starting...

  20. Evaluating analytical approaches for estimating pelagic fish biomass using simulated fish communities

    Yule, Daniel L.; Adams, Jean V.; Warner, David M.; Hrabik, Thomas R.; Kocovsky, Patrick M.; Weidel, Brian C.; Rudstam, Lars G.; Sullivan, Patrick J.

    2013-01-01

    Pelagic fish assessments often combine large amounts of acoustic-based fish density data and limited midwater trawl information to estimate species-specific biomass density. We compared the accuracy of five apportionment methods for estimating pelagic fish biomass density using simulated communities with known fish numbers that mimic Lakes Superior, Michigan, and Ontario, representing a range of fish community complexities. Across all apportionment methods, the error in the estimated biomass generally declined with increasing effort, but methods that accounted for community composition changes with water column depth performed best. Correlations between trawl catch and the true species composition were highest when more fish were caught, highlighting the benefits of targeted trawling in locations of high fish density. Pelagic fish surveys should incorporate geographic and water column depth stratification in the survey design, use apportionment methods that account for species-specific depth differences, target midwater trawling effort in areas of high fish density, and include at least 15 midwater trawls. With relatively basic biological information, simulations of fish communities and sampling programs can optimize effort allocation and reduce error in biomass estimates.

  1. Using Echo Ultrasound from Schooling Fish to Detect and Classify Fish Types

    Yeffry Handoko; Yul.Y. Nazaruddin; Huosheng Hu

    2009-01-01

    Fish finders have already been widely available in the fishing market for a number of years. However, the sizes of these fish finders are too big and their prices are expensive to suit for the research of robotic fish or mini-submarine. The goal of this research is to propose a low-cost fish detector and classifier which suits for underwater robot or submarine as a proximity sensor .With some pre-condition in hardware and algorithms, the experimental results show that the proposed design has good per-formance, with a detection rate of 100 % and a classification rate of 94 %. Both the existing type of fish and the group behavior can be revealed by statistical interpretations such as hovering passion and sparse swimming mode.

  2. 49 CFR 173.218 - Fish meal or fish scrap.

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Fish meal or fish scrap. 173.218 Section 173.218... Fish meal or fish scrap. (a) Except as provided in Column (7) of the HMT in § 172.101 of this subchapter, fish meal or fish scrap, containing at least 6%, but not more than 12% water, is authorized...

  3. Fish Health Management

    For commercial success, a recirculating aquaculture operation must maintain fish at densities far greater than normally found in nature. At the same time, the producer must maintain an environment that supports good fish health. This chapter discusses various aspects of fish health management, inclu...

  4. Ciguatera fish poisoning

    J. Crump; McLay, C.; Chambers, S.

    1999-01-01

    Ciguatera fish poisoning is one of a variety of non-bacterial forms of human seafood poisoning. Consuming large predatory fish from tropical reef ecosystems may be hazardous. We describe a case that is typical of the disease, and illustrates the persistence of neurological symptoms that occur in some patients.


Keywords: ciguatera fish poisoning; ichthyosarcotoxaemia; poisoning; biotoxins

  5. Instructional ladders in computer networks practicums%计算机网络实践课程的阶梯式教学法

    刘春波; 钟安鸣; 顾兆军

    2012-01-01

    尽管大力加强了计算机网络实践教学的人力和物力投入,但教学效果却难以尽如人意.经分析,学生基础不一、接受能力不同是重要原因.阶梯式教学法则可以有效地解决这个问题.它将一个复杂的、高级的教学目标分解为从低级到高级、难度逐渐增大的多个目标,使得终极目标对于每一个学生都是可以实现的.在计算机网络实践课程中,依据教学目标,将网络协议分析和网络应用编程两个模块的教学分别划分为三级阶梯.教学实践表明,在教学目标有所提高的情况下,能够较好实现目标的学生比例从1/2提高到2/3.%Despite a great deal of human and material resources have been devoted to computer network practical teaching, teaching effect is difficult to satisfactory. It is found that students have different basis and different accept capacities is an important cause. Laddered teaching method can effectively solve this problem. It breaks down a complex advanced teaching objective into multiple targets whose difficulty increases gradually from lower to higher so that the ultimate goal can be achieved for each student. In computer networks practicums, teaching processes of network protocol analyzing module and network application programming module are both designed as three-stair ladders according to the teaching objectives. Teaching practices show that in the case of enhanced teaching objective, the proportion of students who can well achieve the objective increases from 1/2 to 2/3.

  6. Generic design of Chinese remaindering schemes

    Dumas, Jean-Guillaume; Gautier, Thierry; Roch, Jean-Louis

    2010-01-01

    We propose a generic design for Chinese remainder algorithms. A Chinese remainder computation consists in reconstructing an integer value from its residues modulo non coprime integers. We also propose an efficient linear data structure, a radix ladder, for the intermediate storage and computations. Our design is structured into three main modules: a black box residue computation in charge of computing each residue; a Chinese remaindering controller in charge of launching the computation and o...

  7. Hydraulic evaluation of fish attraction potential at Merwin Dam fish collection facilities

    This paper discussed a 1:24 scale physical model constructed to optimize a proposed fish trap entrance for a hydroelectric project located on the Lewis River in Washington state. The fish trap entrance will be placed at the Merwin dam, which is located at the furthest point downstream of the main project. The new adult fish passage facilities will collect, sort, and transport adult fish migrating upstream from the ocean. The physical model was used to confirm the preliminary entrance locations as well as to evaluate attraction flows and optimize entrance weir designs. A pump station intake arrangement was also designed to supply fishway attraction flow. It was concluded that the model will also be used to document tailrace flow patterns in order to assist with future studies of fish behavior and dams. 5 figs.

  8. Do Fish Resist?

    Dinesh Joseph Wadiwel

    2016-03-01

    Full Text Available There have been a number of scientific studies on the question of whether fish feel pain. Some have suggested that some fish indeed do feel pain and that this has significant welfare implications (2003. Others have argued that fish do not have the brain development necessary to feel pain. In terms of number of animals killed, the slaughter of sea animals for human consumption significantly exceeds that of any land animals that we use for food, and sea animal slaughter practices frequently lack any basic welfare protections. If fish can be shown to feel pain—or more importantly, if humans can agree that fish feel pain—then this would place a significant question mark over many contemporary fishing practices.  This article substitutes the question 'Do Fish Feel Pain?' with an alternative: 'Do Fish Resist?' It explores the conceptual problems of understanding fish resistance, and the politics of epistemology that surrounds and seeks to develop a conceptual framework for understanding fish resistance to human capture by exploring the development of fishing technologies - the hook, the net and contemporary aquaculture.

  9. Augmented fish health monitoring

    The Bonneville Power Administration (BPA) initiated the Augmented Fish Health Monitoring project in 1986. This project was a five year interagency project involving fish rearing agencies in the Columbia Basin. Historically, all agencies involved with fish health in the Columbia Basin were conducting various levels of fish health monitoring, pathogen screening and collection. The goals of this project were; to identify, develop and implement a standardized level of fish health methodologies, develop a common data collection and reporting format in the area of artificial production, evaluate and monitor water quality, improve communications between agencies and provide annual evaluation of fish health information for production of healthier smolts. This completion report will contain a project evaluation, review of the goals of the project, evaluation of the specific fish health analyses, an overview of highlights of the project and concluding remarks. 8 refs., 1 fig., 4 tabs

  10. Using the decision ladder to understand road user decision making at actively controlled rail level crossings.

    Mulvihill, Christine M; Salmon, Paul M; Beanland, Vanessa; Lenné, Michael G; Read, Gemma J M; Walker, Guy H; Stanton, Neville A

    2016-09-01

    Rail level crossings (RLXs) represent a key strategic risk for railways worldwide. Despite enforcement and engineering countermeasures, user behaviour at RLXs can often confound expectations and erode safety. Research in this area is limited by a relative absence of insights into actual decision making processes and a focus on only a subset of road user types. One-hundred and sixty-six road users (drivers, motorcyclists, cyclists and pedestrians) completed a diary entry for each of 457 naturalistic encounters with RLXs when a train was approaching. The final eligible sample comprised 94 participants and 248 encounters at actively controlled crossings where a violation of the active warnings was possible. The diary incorporated Critical Decision Method probe questions, which enabled user responses to be mapped onto Rasmussen's decision ladder. Twelve percent of crossing events were non-compliant. The underlying decision making was compared to compliant events and a reference decision model to reveal important differences in the structure and type of decision making within and between road user groups. The findings show that engineering countermeasures intended to improve decision making (e.g. flashing lights), may have the opposite effect for some users because the system permits a high level of flexibility for circumvention. Non-motorised users were more likely to access information outside of the warning signals because of their ability to achieve greater proximity to the train tracks and the train itself. The major conundrum in resolving these issues is whether to restrict the amount of time and information available to users so that it cannot be used for circumventing the system or provide more information to help users make safe decisions. PMID:27184305

  11. Selective excitation of branched vibrational ladder in uranium hexafluoride laser isotope separation

    Theoretical investigation was made on the dynamics of initial excitation process in molecular laser isotope separation for uranium hexafluoride (UF6) based on the generalized N-level density-matrix equation derived by Goodman et al. Branched vibrational model due to anharmonic-splitting components for the ν3 mode of UF6 molecule were formalized and phase interferences of density-matrix elements were considered to analyze the selective excitation. Because of a power-broadening effect, no more than 0.05J/cm2 fluence of a laser pulse completely masks high enrichment peaks in broadband (Δν = 2GHz) pumping case. Even when matching the laser frequency with ν3 band (n = 0 → 1) of 238UF6, the enrichment factor (α ≡ Rproduct/Rfeed, R ≡ [235UF6]/[238UF6]; R is the abundance ratio and [ ] means the mole fraction.) does not decrease. A narrow spectral linewidth (Δν = 400MHz) is shown to be essential to achieve a high concentration ratio in the system with a branched N-level ladder as expected from a general two-level system. The exciting frequency, which does not necessarily accord with the ν3 band of 235UF6, gives the maximum enrichment peak. Both the detuning of the optimum frequency and the sharp enrichment peak suggest a direct excitation due to multiphoton resonance. Spectral stability of the laser pulse is also required to excite only the desired isotope for the system with complicated anharmonic-splittings. (author)

  12. Calculating three loop ladder and V-topologies for massive operator matrix elements by computer algebra

    Ablinger, J.; Schneider, C. [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation; Behring, A.; Bluemlein, J.; Freitas, A. de [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Manteuffel, A. von [Mainz Univ. (Germany). Inst. fuer Physik

    2015-09-15

    Three loop ladder and V-topology diagrams contributing to the massive operator matrix element A{sub Qg} are calculated. The corresponding objects can all be expressed in terms of nested sums and recurrences depending on the Mellin variable N and the dimensional parameter ε. Given these representations, the desired Laurent series expansions in ε can be obtained with the help of our computer algebra toolbox. Here we rely on generalized hypergeometric functions and Mellin-Barnes representations, on difference ring algorithms for symbolic summation, on an optimized version of the multivariate Almkvist-Zeilberger algorithm for symbolic integration, and on new methods to calculate Laurent series solutions of coupled systems of differential equations. The solutions can be computed for general coefficient matrices directly for any basis also performing the expansion in the dimensional parameter in case it is expressible in terms of indefinite nested product-sum expressions. This structural result is based on new results of our difference ring theory. In the cases discussed we deal with iterative sum- and integral-solutions over general alphabets. The final results are expressed in terms of special sums, forming quasi-shuffle algebras, such as nested harmonic sums, generalized harmonic sums, and nested binomially weighted (cyclotomic) sums. Analytic continuations to complex values of N are possible through the recursion relations obeyed by these quantities and their analytic asymptotic expansions. The latter lead to a host of new constants beyond the multiple zeta values, the infinite generalized harmonic and cyclotomic sums in the case of V-topologies.

  13. Southeast Alaska ESI: FISH (Fish Polygons)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains biological resource data for estuarine, benthic, and pelagic fish in Southeast Alaska. Vector polygons in this data set represent locations...

  14. American Samoa ESI: FISH (Fish Polygons)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for reef, pelagic, benthic, and estuarine fish species in American Samoa. Vector polygons in this data set...

  15. Swimming and muscle structure in fish

    Spierts, I.L.Y.

    1999-01-01

    In this series of studies the relations between swimming behaviour of fish in general and extreme swimming responses in particular (called fast starts or escape responses) and the structure and ontogeny of the muscle system was investigated. Special attention was paid to relate functional differences between anterior and posterior parts of the axial myotomal muscles of fish to differences in their structural design. In the past considerable knowledge has been accumulated concerning the muscul...

  16. Fish elevator and method of elevating fish

    Truebe, Jonathan; Drooker, Michael S.

    1984-01-01

    A means and method for transporting fish from a lower body of water to a higher body of water. The means comprises a tubular lock with a gated entrance below the level of the lower body of water through which fish may enter the lock and a discharge passage above the level of the upper body of water. The fish raising means in the lock is a crowder pulled upward by a surface float as water from the upper body of water gravitationally flows into the closed lock filling it to the level of the upper body. Water is then pumped into the lock to raise the level to the discharge passage. The crowder is then caused to float upward the remaining distance through the water to the level of the discharge passage by the introduction of air into a pocket on the underside of the crowder. The fish are then automatically discharged from the lock into the discharge passage by the out of water position of the crowder. The movement of the fish into the discharge passage is aided by the continuous overflow of water still being pumped into the lock. A pipe may be connected to the discharge passage to deliver the fish to a selected location in the upper body of water.

  17. Enhancement of lasing without inversion induced by spontaneously generated coherence in an open ladder-type system

    LI Ai-yun; FAN Xi-jun; BU Fan-ge; QIAO Hong-xia; XU Zhi-zhan

    2006-01-01

    It is shown that, in an open ladder-type atomic system with spontaneously generated coherence (SGC),regardless of the existence of an incoherent pumping,a lasing without inversion (LWI) gain is always remarkable larger than in the system without SGC,by adjusting the strength of SGC. Moreover,LWI gain in the system without incoherent pumping is much larger than that with incoherent pumping, within some strength of SGC; while in the corresponding closed system with SGC, we can't obtain LWI gain at any strength of SGC,if no incoherent pumping is applied.

  18. CLASSICAL AREAS OF PHENOMENOLOGY: Population transfer by femtosecond laser pulses in a ladder-type atomic system

    Fan, Xi-Jun; Li, Ai-Yun; Tong, Dian-Min; Liu, Cheng-Pu

    2008-07-01

    The population transfer in a ladder-type atomic system driven by linearly polarized sech-shape femtosecond laser pulses is investigated by numerically solving Schrödinger equation without including the rotating wave approximation (RWA). It is shown that population transfer is mainly determined by the Rabi frequency (strength) of the driving laser field and the chirp rate, and that the ratio of the dipole moments and the pulse width also have a prominent effect on the population transfer. By choosing appropriate values of the above parameters, complete population transfer can be realized.

  19. Generation of non-classical correlated photon pairs via a ladder-type atomic configuration: theory and experiment

    Ding, Dong-Sheng; Zhou, Zhi-Yuan; Shi, Bao-Sen; Zou, Xu-Bo; Guo, Guang-Can

    2012-01-01

    We experimentally generate a non-classical correlated two-color photon pair at 780 and 1529.4 nm in a ladder-type configuration using a hot 85Rb atomic vapor with the production rate of ~107/s. The non-classical correlation between these two photons is demonstrated by strong violation of Cauchy-Schwarz inequality by the factor R=48+-12. Besides, we experimentally investigate the relations between the correlation and some important experimental parameters such as the single-photon detuning, th...

  20. Vaccination in Fish

    Chettri, Jiwan Kumar

    vaccines have reduced the need for usage of antibiotics with more than 99 % since the 1980s. Fish can be vaccinated by three different administration routes: injection, immersion and oral vaccination. Injection vaccination (intraperitoneal injection of vaccine) is the most time consuming and labor...... intensive method, which however, provides the best protection of the fish. Immersion vaccination is used for immunization of a high number of small fish is cost-efficient and fast (30 sec immersion into vaccine). Oral vaccination (vaccine in feed) is the least efficient. As in higher vertebrates fish...... respond to vaccination by increasing the specific antibody titer and by activating the cellular responses. My talk will cover vaccination methods in fish, immune responses and some adverse effect of oil-adjuvanted vaccines in fish with reference to our work in rainbow trout, Oncorhynchus mykiss....

  1. 花草鱼虫智能生态一体机设计与开发%Design and Development of Intelligent and Ecological Machine for the Flowers and Fish

    杨心齐; 刘健; 邓荣涛; 田腾飞; 贾晓磊

    2015-01-01

    随着经济的飞速发展,人们对生活品质的追求愈加重视,水族鱼虫、花草盆景、外出旅游等都成为人们不可缺少的生活乐趣,随之而来的问题是,在家人外出旅游期间,花草鱼虫由谁来照顾。本文研究内容即以HT66FU50单片机为主控芯片,同时结合传感器技术、物联网技术,设计一套将鱼虫换水、喂食、供氧等与花草浇水、施肥、光照等有机结合,养鱼的水中富含植物生长需要的养料,所以排出的水用来浇花草,既可以满足植物对水分的需要,又可以满足植物生长对养分的需求,实现相互补给的生态一体智能控制系统。%With the rapid growth of economy,people pay more and more attention to the pursuit of the quality of life. Feeding aquarium fish and insects,enjoying the flowers and bonsai,travelling and so on are having become a kind of indispensable fun in people’s lives. The attendant issue is that who will take care of these flowers and fish during the period of family travel. A kind of intelligent and ecological machine is proposed in this paper, which chooses HT66FU50 single-chip microcomputer as the main control chip. Many functions are realized, such as feeding, oxygen supply, changing water for fish and watering, fertilizing, providing illumination for flowers though combining sensor technology and the Internet of things technology. The discharged water from fishbowl is used to water flowers, which can both meet the needs of flowers for moisture and nutrients. The system designed is a set of intelligent and ecological system which can achieve mutual recharge.

  2. Fish protein hydrolysates

    Mackie, I.M.

    1982-01-01

    Proteolytic enzymes now available in commercial quantities can be used to liquefy the fish and fish waste presently considered suitable for conversion to fish meal. The products obtained are readily dispersed or dissolved in water and have a high nutritional value. They have been satisfactorily used as substitutes for milk proteins in milk replacers for young animals. Further research is necessary on means of controlling the degree of hydrolysis to give protein preparations with acceptable functional properties as human food supplements. (Refs. 21).

  3. Fish and wildlife surveillance

    This section of the 1994 Hanford Site Environmental Report summarizes the monitoring of radioactive contaminants in fish and wildlife species that inhabit the Colombia River and Hanford Site. Wildlife have access to areas of the Site containing radioactive contamination, and fish can be exposed to contamination in spring water entering the river along the shoreline. Therefore, samples are collected at various locations annually, generally during the hunting or fishing season, for selected species

  4. Fish and wildlife surveillance

    Poston, T.M.

    1995-06-01

    This section of the 1994 Hanford Site Environmental Report summarizes the monitoring of radioactive contaminants in fish and wildlife species that inhabit the Colombia River and Hanford Site. Wildlife have access to areas of the Site containing radioactive contamination, and fish can be exposed to contamination in spring water entering the river along the shoreline. Therefore, samples are collected at various locations annually, generally during the hunting or fishing season, for selected species.

  5. Compliance Program report of findings: FY 79 pesticides and metals in Fish Program (7305.007)

    1982-01-01

    Because fish bioaccumulate* certain chemicals, levels of chemical contaminants in their edible portion must be closely monitored. In recent years, FDA has conducted several surveys designed to determine the occurrence and levels of selected chemicals or groups of chemicals in fish. Previous fish surveillance programs included the Mercury in Wholesale Fish Survey (FY 71), the FY 73 and 74 Comprehensive Fish Surveys, the Canned Tuna Program (FY 75), the Kepone and Mirex Contamination Progra...

  6. Intelligent Fish Freshness Assessment

    Deena Benjamin

    2008-04-01

    Full Text Available Fish species identification and automated fish freshness assessment play important roles in fishery industry applications. This paper describes a method based on support vector machines (SVMs to improve the performance of fish identification systems. The result is used for the assessment of fish freshness using artificial neural network (ANN. Identification of the fish species involves processing of the images of fish. The most efficient features were extracted and combined with the down-sampled version of the images to create a 1D input vector. Max-Win algorithm applied to the SVM-based classifiers has enhanced the reliability of sorting to 96.46%. The realisation of Cyranose 320 Electronic nose (E-nose, in order to evaluate the fish freshness in real-time, is experimented. Intelligent processing of the sensor patterns involves the use of a dedicated ANN for each species under study. The best estimation of freshness was provided by the most sensitive sensors. Data was collected from four selected species of fishes over a period of ten days. It was concluded that the performance can be increased using individual trained ANN for each specie. The proposed system has been successful in identifying the number of days after catching the fish with an accuracy of up to 91%.

  7. Of Fish and Micrornas

    Bela-Ong, Dennis; Schyth, Brian Dall; Lorenzen, Niels

    Fish is an important small vertebrate multidisciplinary model for investigating various aspects of reproduction, development, disease (immunology, toxicology, carcinogenesis), and aging. It is also an important model for comparative and evolutionary studies because it represents the lower...... to the mechanisms of control of gene expression, impacting a broad range of biological processes. Thus far, >25, 000 miRNA sequences have been identified in 193 species, including fish. In fish, the interest on miRNAs started with the analysis of their expression and function during embryonic development. In our...... selection markers to identify disease-resistant fish....

  8. Yakima Basin Fish Passage Project, Phase 2

    Implementation of the Yakima Basin Fish Passage Project -- Phase 2 would significantly improve the production of anadromous fish in the Yakima River system. The project would provide offsite mitigation and help to compensate for lower Columbia River hydroelectric fishery losses. The Phase 2 screens would allow greater numbers of juvenile anadromous fish to survive. As a consequence, there would be higher returns of adult salmon and steelhead to the Yakima River. The proposed action would play an integral part in the overall Yakima River anadromous fish enhancement program (fish passage improvement, habitat enhancement, hatchery production increases, and harvest management). These would be environmental benefits associated with implementation of the Fish Passage and Protective Facilities Phase 2 Project. Based on the evaluation presented in this assessment, there would be no significant adverse environmental impacts if the proposed action was carried forward. No significant adverse environmental effects have been identified from construction and operation of the Yakima Phase 2 fish passage project. Proper design and implementation of the project will ensure no adverse effects will occur. Based on the information in this environmental analysis, BPA's and Reclamation's proposal to construct these facilities does not constitute a major Federal action that could significantly affect the quality of the human environment. 8 refs., 4 figs., 6 tabs

  9. Exact zero-temperature correlation functions for two-leg Hubbard ladders and carbon nanotubes

    Motivated by recent work of Lin, Balents, and Fisher [Phys. Rev. B 58, 1794 (1998)], we compute correlation functions at zero temperature for weakly coupled two-leg Hubbard ladders and (N,N) armchair carbon nanotubes. In this paper it was argued that such systems renormalize towards the SO(8) Gross-Neveu model, an integrable theory. We exploit this integrability to perform the computation at the SO(8) invariant point. Any terms breaking the SO(8) symmetry can be treated systematically in perturbation theory, leading to a model with the same qualitative features as the integrable theory. Using said correlators, we determine the optical conductivity, the single-particle spectral function, and the I-V curve for tunneling into the system from an external metallic lead. The frequency, ω, dependent optical conductivity is determined exactly for ω1/2 and not the ω-1/2 one would expect from the van Hove singularity in the density of states. Similarly, we obtain the exact single-particle spectral function for energies less than 3m. The latter possesses a δ function peak arising from single-particle excitations, together with a two-particle continuum for ω≥2m. The final quantity we compute is the tunneling I-V curve to lowest nonvanishing order in the tunneling matrix elements. For this quantity, we present exact results for voltages, V<(1+√(3))m. The resulting differential conductance is marked by a finite jump at ω=2m, the energy of the onset of tunneling into the continuum of two-particle states. Through integrability, we are able to characterize this jump exactly. All calculations are done through form-factor expansions of correlation functions. These give exact closed form expressions for spectral functions because the SO(8) Gross-Neveu model is massive: each term in the expansion has an energy threshold below which it does not contribute. Thus, we obtain exact results below certain thresholds by computing a finite number of terms in this series. Previous to

  10. On the use of a risk ladder: Linking public perception of risks associated with indoor air with cognitive elements and attitudes toward risk reduction

    Moschandreas, D. J.; Chang, P. E.

    In recent years a number of building managers have invested small amounts of money to measure indoor air quality in offices and other non-industrial buildings. Their objective is to reduce the number of occupant complaints, and not necessarily to reduce the risk associated with such complaints. Clearly, reduction of the risk would require greater investment of funds and effort. This paper focuses on individuals and the amount of money they are willing to invest in order to reduce risks associated with indoor air pollution in their home. Psychologists assert that lay judgement of risks are influenced by cognitive biases and attitudes. This study investigates the possibility that cognitive elements and general attitudes influence not only the perceived risk associated with exposures to indoor air pollutants, but also the willingness of individuals to invest in order to reduce the risk. A three-stage study was performed to determine some of the factors that influence public decisions to control the quality of the air inside their home. The study is focused on the design of a risk ladder, and the survey of 400 randomly selected individuals in the Chicago metropolitan area. The survey was designed to determine if demographics, smoking, education, or income influence the desire of individuals to invest in order to reduce indoor air pollution. The following conclusions were reached: (i) public awareness of indoor air pollution is high; (ii) media campaigns on indoor air pollution affect the determination of the specific pollutant the public perceives as important, but do not influence the public's desire to invest larger amounts of money to reduce risks from exposures to air pollutants in the residential environment; (iii) the public is not willing to spend large amounts of money to reduce indoor residential air pollution; (iv) education does not affect the level of awareness regarding indoor air pollution, but it increases the willingness to invest in an effort to reduce

  11. Optimal swim speeds by respirometer: an analysis of three neotropical species

    Hersília de Andrade e Santos; Edna Maria de Faria Viana; Paulo Santos Pompeu; Carlos Barreira Martinez

    2012-01-01

    The swimming ability of neotropical fish species is an important aspect for fish ladder designs. Especially in Latin America, where fish ladders are highly selective, fish strategies to negotiate the passage should be studied focusing on target species. This paper shows the swimming ability of three neotropical species (Leporinus reinhardti, Pimelodus maculatus and Prochilodus costatus), from São Francisco river basin. Respirometer was employed for data collection. Regarding the critical and ...

  12. Fish silage as feed ingredient for fish and livestock

    Rurangwa, E.; Vuuren, van, T.; Poelman, M.

    2014-01-01

    The present report analyses through a literature review the potential of fish silage to valorise fish processing by-products into economically relevant protein sources for fish and livestock feed production in East Africa.

  13. Magnetic properties of the two-leg zig-zag ladder in quantum spin system NH4CuCl3

    Numerical analysis of the two-leg zig-zag ladder as a single chain with next-nearest neighbour interactions has been formulated by Cabra (1999) with the following Hamiltonian. Other formulation for two leg zig-zag ladder with dimerized chains and coupling between the chains. From these formulations, we study the closing of the gap at zero magnetization by means of the fine-tuning mechanism and disappearance of the 1/2 plateau (gap) at finite by alternating dimerization of the chains along the rungs. We also described NH4CuCI3 under high magnetic fields in a two-leg system

  14. Finite element analysis and experiment research on aluminum alloy ladder bowl with viscous pressure forming(VPF)

    2002-01-01

    The process parameters of aluminum alloy ladder bowl with viscous pressure forming and solid metal punch forming were numerically simulated by commercial finite element software DEFORM.The influence of blank holder pressure(BHP)on the formability of sheet metal was investigated.It was found that lower BHP does benefit to the distribution of thickness both with VPF and with solid punch forming.The forming force needed in VPF is bigger than that of with solid punch forming at the same stroke.The distribution of thickness with VPF is more uniform than that of with solid punch forming.Compared with solid punch forming,the damage values of workpiece at the top convex comer are lower by VPF.It was also shown that fracture tendency could be reduced with VPF,so that means the formability is improved.At the same time,aluminum alloy ladder bowl was manufactured with VPF.The results show that the simulation results are in agreement with the experimental data very well.

  15. Structure-Property Relationship for Two-Photon Absorbing Multiporphyrins: Supramolecular Assembly of Highly-Conjugated Multiporphyrinic Ladders and Prisms

    Easwaramoorthi, Shanmugam; Jang, So Young; Yoon, Zin Seok; Lim, Jong Min; Lee, Cheng-Wei; Mai, Chi-Lun; Liu, Yen-Chun; Yeh, Chen-Yu; Vura-Weis, Josh; Wasielewski, Michael R.; Kim, Dongho (NWU); (Yonsei); (NSHU)

    2008-10-03

    Two-photon absorption (TPA) phenomena of a series of single-strand as well as supramolecular self-assembled ladders and prisms of highly conjugated ethyne bridged multiporphyrin dimer, trimer, and star shaped pentamer have been investigated. The ligand mediated self-assembled supramolecular structures were characterized by UV-visible spectroscopy and small- and wide-angle X-ray scattering (SAXS/WAXS) analysis. The TPA cross section values of multiporphyrins increase nonlinearly from {approx}100 to {approx}18000 GM with an increased number of porphyrin units and elongated ?-conjugation length by virtue of charge transfer and excited-state cumulenic configurations. The observed opposite TPA behavior between their supramolecular ladder and prism configurations necessitates the importance of interstrand interactions between the multiporphyrinic units and the overall shape of the assembly. Furthermore, the diminished TPA cross section of the pentamer, despite the increased ?-conjugation resulting from duplex formation suggests that destabilizing the essential functional configurations at the cost of elongation of ?-delocalization pathway must cause unfavorable effects. We have also shown that one- and two-photon allowed energy-levels of linear multiporphyrins are nearly isoenergetic and the latter transition originates exclusively from the extent of ?-delocalization within the molecule. The identical TPA maximum position of the trimer and pentamer indicates that the TPA of the pentamer arises only from its basic trimer unit in spite of its extended two-dimensional {pi}-conjugation pathway involving five porphyrinic units.

  16. An approach to global rovibrational analysis based on anharmonic ladder operators: Application to Hydrogen Selenide (H280Se)

    Graphical abstract: Schematic diagram of a bent triatomic molecule, depicting the atom numbering, and molecular axis system. An algebraic approach to perform global rovibrational analysis is presented. Highlights: ► Novel approach for a global rovibrational analysis of polyatomic molecules spectra. ► One-dimensional vibron model limit combined with rotational degrees of freedom. ► Phase space Hamiltonian written in terms of anharmonic ladder operators. ► Algebraic calculations performed with a symmetry-adapted rovibrational basis. ► Description of the rovibrational spectrum of H2Se in the ground electronic state. - Abstract: An algebraic approach to perform global rovibrational analysis of molecular spectra is presented. The approach combines the one-dimensional limit of the vibron model with rotational degrees of freedom. The model is based on the expression of the phase space Hamiltonian in terms of anharmonic ladder operators and the use of a symmetry-adapted basis set given by the linear combination of products of local vibrational and rotational wavefunctions. As an example we model the rovibrational spectra of a bent triatomic molecule, providing a global analysis for vibrational bands up to polyad 12 and Jmax = 5 of Hydrogen Selenide (H2Se). Satisfactory fits of vibrational and rovibrational energies are obtained. A prediction of 2579 rovibrational energies up to J ⩽ 5 and polyad 12 for the 140 lowest vibrational bands is also obtained. A possible extension of the model to reach spectroscopic quality results in larger molecular systems is also given.

  17. Preventing AVF thrombosis: the rationale and design of the Omega-3 fatty acids (Fish Oils and Aspirin in Vascular access OUtcomes in REnal Disease (FAVOURED study

    Rosman Johan

    2009-01-01

    Full Text Available Abstract Background Haemodialysis (HD is critically dependent on the availability of adequate access to the systemic circulation, ideally via a native arteriovenous fistula (AVF. The Primary failure rate of an AVF ranges between 20–54%, due to thrombosis or failure of maturation. There remains limited evidence for the use of anti-platelet agents and uncertainty as to choice of agent(s for the prevention of AVF thrombosis. We present the study protocol for a randomised, double-blind, placebo-controlled, clinical trial examining whether the use of the anti-platelet agents, aspirin and omega-3 fatty acids, either alone or in combination, will effectively reduce the risk of early thrombosis in de novo AVF. Methods/Design The study population is adult patients with stage IV or V chronic kidney disease (CKD currently on HD or where HD is planned to start within 6 months in whom a planned upper or lower arm AVF is to be the primary HD access. Using a factorial-design trial, patients will be randomised to aspirin or matching placebo, and also to omega-3 fatty acids or matching placebo, resulting in four treatment groups (aspirin placebo/omega-3 fatty acid placebo, aspirin/omega-3 fatty acid placebo, aspirin placebo/omega-3 fatty acid, aspirin/omega-3 fatty acid. Randomisation will be achieved using a dynamic balancing method over the two stratification factors of study site and upper versus lower arm AVF. The medication will be commenced pre-operatively and continued for 3 months post surgery. The primary outcome is patency of the AVF at three months after randomisation. Secondary outcome measures will include functional patency at six and twelve months, primary patency time, secondary (assisted patency time, and adverse events, particularly bleeding. Discussion This multicentre Australian and New Zealand study has been designed to determine whether the outcome of surgery to create de novo AVF can be improved by the use of aspirin and/or omega-3 fatty

  18. Mismatch between fishway operation and timing of fish movements: a risk for cascading effects in partial migration systems.

    van Leeuwen, Casper H A; Museth, Jon; Sandlund, Odd T; Qvenild, Tore; Vøllestad, L Asbjørn

    2016-04-01

    Habitat fragmentation is a growing problem worldwide. Particularly in river systems, numerous dams and weirs hamper the movement of a wide variety of species. With the aim to preserve connectivity for fish, many barriers in river systems are equipped with fishways (also called fish passages or fish ladders). However, few fishways provide full connectivity. Here we hypothesized that restricted seasonal opening times of fishways can importantly reduce their effectiveness by interfering with the timing of fish migration, for both spring- and autumn-spawning species. We empirically tested our hypothesis, and discuss the possible eco-evolutionary consequences of affected migration timing. We analyzed movements of two salmonid fishes, spring-spawning European grayling (Thymallus thymallus) and autumn-spawning brown trout (Salmo trutta), in Norway's two largest river systems. We compared their timing of upstream passage through four fishways collected over 28 years with the timing of fish movements in unfragmented river sections as monitored by radiotelemetry. Confirming our hypothesis, late opening of fishways delayed the migration of European grayling in spring, and early closure of fishways blocked migration for brown trout on their way to spawning locations during late autumn. We show in a theoretical framework how restricted opening times of fishways can induce shifts from migratory to resident behavior in potamodromous partial migration systems, and propose that this can induce density-dependent effects among fish accumulating in lower regions of rivers. Hence, fragmentation may not only directly affect the migratory individuals in the population, but may also have effects that cascade downstream and alter circumstances for resident fish. Fishway functionality is inadequate if there is a mismatch between natural fish movements and fishway opening times in the same river system, with ecological and possibly evolutionary consequences for fish populations. PMID

  19. Landbird Monitoring Protocol for the U.S. Fish and Wildlife Service, Midwest and Northeast Regions

    US Fish and Wildlife Service, Department of the Interior — This protocol is a standardized tool for monitoring breeding landbirds by use of point counts and was designed for use in U.S. Fish and Wildlife Service FWS Regions...

  20. CO-Selenium in fish tissue: Prediction equations for conversion between whole body, muscle, and eggs

    US Fish and Wildlife Service, Department of the Interior — The lower Gunnison River and the Colorado River are designated critical habitat for two endangered fish species: the Colorado pikeminnow (Ptychocheilus lucius) and...

  1. Design

    Volf, Mette

    2009-01-01

    Design - proces og metode går bag om designerens arbejde og giver et indblik i den skabelsesproces, som designeren er involveret i. Bogen er enestående, fordi den fokuserer på processens flygtige og komplekse karakter, afmystificerer den og gør den operationel - uden at fjerne dens magi. Ud over at...

  2. Design

    Buchanan, Richard; Cross, Nigel; Durling, David; Nelson, Harold; Owen, Charles; Valtonen, Anna; Boling, Elizabeth; Gibbons, Andrew; Visscher-Voerman, Irene

    2013-01-01

    Scholars representing the field of design were asked to identify what they considered to be the most exciting and imaginative work currently being done in their field, as well as how that work might change our understanding. The scholars included Richard Buchanan, Nigel Cross, David Durling, Harold Nelson, Charles Owen, and Anna Valtonen. Scholars…

  3. Fish Vaccines in Aquaculture

    Vaccination is a proven, cost-effective method to prevent infectious diseases in animals. Current fish vaccines can be categorized as killed fish vaccines or modified live vaccines. The major advantage of live vaccine is their ability to stimulate both cell-mediated and humoral immune responses for ...

  4. Stress in Fish

    Stress in fish involves a condition disruptive of physiological homeostasis that occurs in response to unfavorable external influences and is capable of adversely affecting fish. Any stimulus that provokes stress responses is known as a stressor, disrupting a stable condition and causing a response....

  5. From Fishing to Fish Processing: Separation of Fish from Crustaceans in the Norway Lobster-Directed Multispecies Trawl Fishery Improves Seafood Quality.

    Junita D Karlsen

    Full Text Available Fishing gears have negative impacts on seafood quality, especially on fish in the mixed trawl fishery targeting Norway lobster (Nephrops norvegicus. In this fishery, which is worth about €80 millions in Denmark alone, the quality of fish can be significantly improved by simple gear changes. A trawl codend divided into an upper and lower codend was designed to separate fish from Norway lobster during the fishing process by encourage fish to swim into the upper codend by using a frame at the entrance of the lower codend. Separate codends for fish and Norway lobster in the same gear provide the opportunity to selectively reduce small low-value fish, which will reduce catch weight and sorting time onboard the vessel. For this horizontally divided test codend and a standard codend, in which the catch was mixed, quality assessments were performed on the same batches of fish during three steps of the value chain: i aboard the fishing vessel; ii at the Fishermen's Collection Central, and iii in the production plant. Four species of fish and fillets from fish caught in the upper codend of the test codend were of significantly better quality for several of the assessed parameters compared with those caught in the standard codend: i newly caught fish showed significantly less scale loss and discolourations and had significantly better texture; ii landed fish had significantly better skin appearance and texture and significantly fewer discolourations; and iii fillets showed significantly fewer blood spots and had significantly better texture. There were no differences in injuries for newly caught fish or gaping and bruises for fillets between the test and standard codends. The decrease in catch-related damages in the test codend is explained by little contact between fish and animals with hard or spiny surfaces due to successful separation of fish and Norway lobster into the upper and lower codends, respectively, and by lower catch weight in the upper

  6. Biannual Fish Survey, Spring 1993

    US Fish and Wildlife Service, Department of the Interior — The biannual fish survey was initiated in 1989 to monitor population trends of federally endangered fish species at Ash Meadows National Wildlife Refuge. Item 421...

  7. Minutes of Fish Barrier Workshop

    US Fish and Wildlife Service, Department of the Interior — Minutes of Fish Barrier Workshop held 27 May 2009 at DOC Waikato Area Office. Lists attendees and highlights topics to be covered in Fish Barrier Workshop.

  8. A relational database of post-harvest fish losses

    Smith, M. C.; Venn, J.; Cheke, R.A.; Ward, A. R.

    1997-01-01

    The article describes FISHLOSS, a database of post-harvest fish losses devised by the Natural Resources Institute (NRI), UK. The database contains 450 records of post-harvest fish losses from 150 sources. The majority of the estimates are shelf-life estimates. Designed to be a reference for people studying post-harvest fish losses, it draws attention to areas requiring future research to identify significant losses and the factors which cause them. All researchers and users are encouraged to ...

  9. Economics of Fish Marketing in Central Uganda: A Preliminary Analysis

    Bukenya, James O.; Hyuha, Theodora; Twinamasiko, Julius; Molnar, Joseph J.

    2012-01-01

    The paper examines profitability and market performance of small-scale fish traders selected randomly from a cross-section of nine fish markets in four districts in Central Uganda. Data were collected through a structured questionnaire which was designed to solicit information on traders’ socio-economic characteristics, marketing characteristics, operating costs and returns, and problems associated with fish marketing in the study area. Percentages were used to describe the socio-economic cha...

  10. Value based segmentation : a study of wild fish versus farmed fish consumption in Nha Trang

    Suneth Jayampathi, R.P.S.

    2010-01-01

    The primary purpose of this study was to identify market segments based on personal values, values and lifestyles, environmental concern, fish welfare concern, ethical concern for fish farming and health involvement. A self-administrated questionnaire was conducted on a convenience sample of 209 Vietnamese consumers. It was designed to investigate consumers’ concern for issues used as segmentation basis together with variables used in profiling the segments. The measurement scales used in thi...

  11. Design of Studies for Development of BPA Fish and Wildlife Mitigation Accounting Policy Phase II, Volume II, 1985-1988 Technical Report.

    Kneese, Allen V.

    1988-08-01

    The incremental costs of corrective measures to lessen the environmental impacts of the hydroelectric system are expected to increase and difficult questions to arise about the costs, effectiveness, and justification of alternative measures and their systemwide implications. The BPA anticipate this situation by launching a forward-looking research program aimed at providing methodological tools and data suitable for estimating the productivity and cost implications of mitigation alternatives in a timely manner with state-of-the-art accuracy. Resources for the Future (RFF) agreed at the request of the BPA to develop a research program which would provide an analytical system designed to assist the BPA Administrator and other interested and responsible parties in evaluating the ecological and economic aspects of alternative protection, enhancement, and mitigation measures. While this progression from an ecological understanding to cost-effectiveness analyses is straightforward in concept, the complexities of the Columbia River system make the development of analytical methods far from simple in practice. The Phase 2 final report outlines the technical issues involved in developing an analytical system and proposes a program of research to address these issues. The report is presented in the Summary Report (Volume 1), and the present volume which consists of three technical reports: Part I, Modeling the Salmon and Steelhead Fisheries of the Columbia River Basin; Part II, Models for Cost-Effectiveness Analysis; and Part III, Ocean Fisheries Harvest Management.

  12. The ladder-shaped polyether toxin gambierol anchors the gating machinery of Kv3.1 channels in the resting state.

    Kopljar, Ivan; Labro, Alain J; de Block, Tessa; Rainier, Jon D; Tytgat, Jan; Snyders, Dirk J

    2013-03-01

    Voltage-gated potassium (Kv) and sodium (Nav) channels are key determinants of cellular excitability and serve as targets of neurotoxins. Most marine ciguatoxins potentiate Nav channels and cause ciguatera seafood poisoning. Several ciguatoxins have also been shown to affect Kv channels, and we showed previously that the ladder-shaped polyether toxin gambierol is a potent Kv channel inhibitor. Most likely, gambierol acts via a lipid-exposed binding site, located outside the K(+) permeation pathway. However, the mechanism by which gambierol inhibits Kv channels remained unknown. Using gating and ionic current analysis to investigate how gambierol affected S6 gate opening and voltage-sensing domain (VSD) movements, we show that the resting (closed) channel conformation forms the high-affinity state for gambierol. The voltage dependence of activation was shifted by >120 mV in the depolarizing direction, precluding channel opening in the physiological voltage range. The (early) transitions between the resting and the open state were monitored with gating currents, and provided evidence that strong depolarizations allowed VSD movement up to the activated-not-open state. However, for transition to the fully open (ion-conducting) state, the toxin first needed to dissociate. These dissociation kinetics were markedly accelerated in the activated-not-open state, presumably because this state displayed a much lower affinity for gambierol. A tetrameric concatemer with only one high-affinity binding site still displayed high toxin sensitivity, suggesting that interaction with a single binding site prevented the concerted step required for channel opening. We propose a mechanism whereby gambierol anchors the channel's gating machinery in the resting state, requiring more work from the VSD to open the channel. This mechanism is quite different from the action of classical gating modifier peptides (e.g., hanatoxin). Therefore, polyether toxins open new opportunities in structure

  13. Oral vaccination of fish: Lessons from humans and veterinary species.

    Embregts, Carmen W E; Forlenza, Maria

    2016-11-01

    The limited number of oral vaccines currently approved for use in humans and veterinary species clearly illustrates that development of efficacious and safe oral vaccines has been a challenge not only for fish immunologists. The insufficient efficacy of oral vaccines is partly due to antigen breakdown in the harsh gastric environment, but also to the high tolerogenic gut environment and to inadequate vaccine design. In this review we discuss current approaches used to develop oral vaccines for mass vaccination of farmed fish species. Furthermore, using various examples from the human and veterinary vaccine development, we propose additional approaches to fish vaccine design also considering recent advances in fish mucosal immunology and novel molecular tools. Finally, we discuss the pros and cons of using the zebrafish as a pre-screening animal model to potentially speed up vaccine design and testing for aquaculture fish species. PMID:27018298

  14. Why do fish school?

    Matz LARSSON

    2012-01-01

    Synchronized movements (schooling) emit complex and overlapping sound and pressure curves that might confuse the inner ear and lateral line organ (LLO) of a predator.Moreover,prey-fish moving close to each other may blur the electro-sensory perception of predators.The aim of this review is to explore mechanisms associated with synchronous swimming that may have contributed to increased adaptation and as a consequence may have influenced the evolution of schooling.The evolutionary development of the inner ear and the LLO increased the capacity to detect potential prey,possibly leading to an increased potential for cannibalism in the shoal,but also helped small fish to avoid joining larger fish,resulting in size homogeneity and,accordingly,an increased capacity for moving in synchrony.Water-movements and incidental sound produced as by-product of locomotion (ISOL) may provide fish with potentially useful information during swimming,such as neighbour body-size,speed,and location.When many fish move close to one another ISOL will be energetic and complex.Quiet intervals will be few.Fish moving in synchrony will have the capacity to discontinue movements simultaneously,providing relatively quiet intervals to allow the reception of potentially critical environmental signals.Besides,synchronized movements may facilitate auditory grouping of ISOL.Turning preference bias,well-functioning sense organs,good health,and skillful motor performance might be important to achieving an appropriate distance to school neighbors und aid the individual fish in reducing time spent in the comparatively less safe school periphery.Turning preferences in ancestral fish shoals might have helped fish to maintain groups and stay in formarion,reinforcing aforementioned predator confusion mechanisms,which possibly played a role in the lateralization of the vertebrate brain [Current Zoology 58 (1):116-128,2012].

  15. Why do fish school?

    Matz LARSSON

    2012-02-01

    Full Text Available Synchronized movements (schooling emit complex and overlapping sound and pressure curves that might confuse the inner ear and lateral line organ (LLO of a predator. Moreover, prey-fish moving close to each other may blur the electro-sensory perception of predators. The aim of this review is to explore mechanisms associated with synchronous swimming that may have contributed to increased adaptation and as a consequence may have influenced the evolution of schooling. The evolutionary development of the inner ear and the LLO increased the capacity to detect potential prey, possibly leading to an increased potential for cannibalism in the shoal, but also helped small fish to avoid joining larger fish, resulting in size homogeneity and, accordingly, an increased capacity for moving in synchrony. Water-movements and incidental sound produced as by-product of locomotion (ISOL may provide fish with potentially useful information during swimming, such as neighbour body-size, speed, and location. When many fish move close to one another ISOL will be energetic and complex. Quiet intervals will be few. Fish moving in synchrony will have the capacity to discontinue movements simultaneously, providing relatively quiet intervals to allow the reception of potentially critical environmental signals. Besides, synchronized movements may facilitate auditory grouping of ISOL. Turning preference bias, well-functioning sense organs, good health, and skillful motor performance might be important to achieving an appropriate distance to school neighbors and aid the individual fish in reducing time spent in the comparatively less safe school periphery. Turning preferences in ancestral fish shoals might have helped fish to maintain groups and stay in formation, reinforcing aforementioned predator confusion mechanisms, which possibly played a role in the lateralization of the vertebrate brain [Current Zoology 58 (1: 116–128, 2012].

  16. Feasibility of Documenting and Estimating Adult Fish Passage at Large Hydroelectric Facilities in the Snake River Using Video Technology; 1993 Final Report.

    Hatch, Douglas R.; Pederson, David R.; Fryer, Jeffrey

    1994-07-01

    Lower Granite Dam on the Snake River to evaluate the feasibility of using video technology to document and estimate fish ladder passage of chinook salmon Oncorhynchus tshawytscha, sockeye salmon O. nerka, and steelhead O. mykiss. A video system was to produced video images during salmon passage periods. A technician identified and counted fish images from the video record. Fish ladder passage estimates of target species made from the video record were similar to estimates made by on-site counters during daytime periods, indicating that the two methods were relatively precise. We also found that a significant percentage (6.4% and 8.3%) of target salmonids migrated during nighttime periods when on-site counts were not typically made during the two years of study. Analysis of the video record permitted verification of individual sockeye salmon identified and counted by on-site count personnel, and provided data useful to managers of this ESA-listed stock. Analysis of the video record also permitted collection of additional data such as length measurements of individual specimens, which was used to regulate a fishery located upstream.

  17. Real-space localization and quantification of hole distribution in chain-ladder Sr3Ca11Cu24O41 superconductor.

    Bugnet, Matthieu; Löffler, Stefan; Hawthorn, David; Dabkowska, Hanna A; Luke, Graeme M; Schattschneider, Peter; Sawatzky, George A; Radtke, Guillaume; Botton, Gianluigi A

    2016-03-01

    Understanding the physical properties of the chain-ladder Sr3Ca11Cu24O41 hole-doped superconductor has been precluded by the unknown hole distribution among chains and ladders. We use electron energy-loss spectrometry (EELS) in a scanning transmission electron microscope (STEM) at atomic resolution to directly separate the contributions of chains and ladders and to unravel the hole distribution from the atomic scale variations of the O-K near-edge structures. The experimental data unambiguously demonstrate that most of the holes lie within the chain layers. A quantitative interpretation supported by inelastic scattering calculations shows that about two holes are located in the ladders, and about four holes in the chains, shedding light on the electronic structure of Sr3Ca11Cu24O41. Combined atomic resolution STEM-EELS and inelastic scattering calculations is demonstrated as a powerful approach toward a quantitative understanding of the electronic structure of cuprate superconductors, offering new possibilities for elucidating their physical properties. PMID:27051872

  18. Calibrating the cosmic distance scale ladder: the role of the sound horizon scale and the local expansion rate as distance anchors

    Cuesta, Antonio J; Riess, Adam; Jimenez, Raul

    2014-01-01

    We exploit cosmological-model independent measurements of the expansion history of the Universe to provide a cosmic distance ladder. These are supernovae type Ia used as standard candles (at redshift between 0.01 and 1.3) and baryon acoustic oscillations (at redshifts between 0.1 and 0.8) as standard rulers. We calibrate (anchor) the ladder in two ways: first using the local $H_0$ value as an anchor at $z$ = 0 (effectively calibrating the standard candles) and secondly using the cosmic microwave background-inferred sound-horizon scale as an anchor (giving the standard ruler length) as an inverse distance ladder. Both methods are consistent, but the uncertainty in the expansion history $H(z)$ is smaller if the sound horizon scale is used. We present inferred values for the sound horizon at radiation drag $r_d$ which do not rely on assumptions about the early expansion history nor on cosmic microwave background measurements but on the cosmic distance ladder and baryon acoustic oscillations measurements. We also...

  19. Up and down the sanitation ladder: Harmonizing the treatment and multiple-barrier perspectives on risk reduction in wastewater irrigated agriculture

    Keraita, Bernard; Drechsel, P.; Konradsen, Flemming

    2010-01-01

    perspective has strengths and mitations. Rather than being opposing philosophies, they both support health risk reduction but in different ways depending on the level of the country in the sanitation ladder. Since each perspective has limitations, the recommendation is to capitalize on their strengths and...

  20. All Fish for China?

    Villasante, Sebastián; Rodríguez-González, David; Antelo, Manel; Rivero-Rodríguez, Susana; de Santiago, José A.; Macho, Gonzalo

    2013-01-01

    In this paper we examine the effect of Gross Domestic Product (GDP) on the level of fish intake in China in comparison with the rest of the world. We also analyse the origin and destination of China’s seafood products in order to understand the main patterns during the last decades. The results show that in the 1961–2011 period the rate of growth of the GDP in China doubled that of other developing regions, while the daily fish intake of China increased fourfold, making China the largest fish...

  1. Decrease in myostatin by ladder-climbing training is associated with insulin resistance in diet-induced obese rats

    Tang Liang; Luo Kai; Liu Chentao; Wang Xudan; Zhang Didi; Chi Aiping; Zhang Jing

    2014-01-01

    Background Suppression of myostatin (MSTN) has been associated with skeletal muscle atrophy and insulin resistance (IR).However,few studies link MSTN suppression by ladder-climbing training (LCT) and IR.Therefore,we intended to identify the correlation with IR between LCT and to analyze the signaling pathways through which MSTN suppression by LCT regulates IR.Methods The rats were randomly assigned to two types of diet:normal pellet diet (NPD,n=8) and high-fat diet (HFD,n=16).After 8 weeks,the HFD rats were randomly re-assigned to two groups (n=8 for each group):HFD sedentary (HFD-S) and high-fat diet ladder-climbing training (HFD-LCT).HFD-LCT rats were assigned to LCT for 8 weeks.Western blotting,immunohistochemistry and enzyme assays were used to measure expression levels and activities of MSTN,GLUT4,PI3K,Akt and Akt-activated targets (mTOR,FoxO1 and GSK-3β).Results The LCT significantly improved IR and whole-body insulin sensitivity in HDF-fed rats.MSTN protein levels decreased in matching serum (42%,P=0.007) and muscle samples (25%,P=0.035) and its receptor mRNA expression also decreased (16%,P=0.041) from obese rats after LCT.But the mRNA expression of insulin receptor had no obvious changes in LCT group compared with NPD and HFD-S groups (P=0.074).The ladder-climbing training significantly enhanced PI3K activity (1.7-fold,P=0.024) and Akt phosphorylation (83.3%,P=0.022) in HFD-fed rats,significantly increased GLUT4 protein expression (84.5%,P=-0.036),enhanced phosphorylation of mTOR (4.8-fold,P <0.001) and inhibited phosphorylation of FoxO1 (57.7%,P=0.020),but did not affect the phosphorylation of GSK-3β.Conclusions The LCT significantly reduced IR in diet-induced obese rats.MSTN may play an important role in regulating IR and fat accumulation by LCT via PI3K/Akt/mTOR and PI3K/Akt/FoxO1 signaling pathway in HFD-fed rats.

  2. Finite range and upper branch effects on itinerant ferromagnetism in repulsive Fermi gases: Bethe–Goldstone ladder resummation approach

    We investigate the ferromagnetic transition in repulsive Fermi gases at zero temperature with upper branch and effective range effects. Based on a general effective Lagrangian that reproduces precisely the two-body s-wave scattering phase shift, we obtain a nonperturbative expression of the energy density as a function of the polarization by using the Bethe–Goldstone ladder resummation. For hard sphere potential, the predicted critical gas parameter kFa=0.816 and the spin susceptibility agree well with the results from fixed-node diffusion Monte Carlo calculations. In general, positive and negative effective ranges have opposite effects on the critical gas parameter kFa: While a positive effective range reduces the critical gas parameter, a negative effective range increases it. For attractive potential or Feshbach resonance model, the many-body upper branch exhibits an energy maximum at kFa=α with α=1.34 from the Bethe–Goldstone ladder resummation, which is qualitatively consistent with experimental results. The many-body T-matrix has a positive-energy pole for kFa>α and it becomes impossible to distinguish the bound state and the scattering state. These positive-energy bound states become occupied and therefore the upper branch reaches an energy maximum at kFa=α. In the zero range limit, there exists a narrow window (0.86ladder resummation approach. • Positive and negative effective ranges have opposite effects on the critical gas parameter. • The upper branch Fermi gas exhibits an energy maximum and reentrant

  3. Effects of radiations on ornamental fish

    Radiation is a process in which energetic particles or energetic waves travel through a medium or space. There are two distinct types of radiations: ionizing and non-ionizing. Ultraviolet, X-rays, and gamma rays are some examples of radiation. 'Ornamental fish' is designed for aquatic hobbyists and the aquatic industry for several purposes. UV light has two primary uses in fish culture: Controlling green water and disinfecting the water supply. Many proponents of UV disinfection sometimes overlook the additional benefits relating to ornamental fish; those being that cleaner water reduces the stress on the fish by not having to fight off diseases, thus enhancing its immune system and leading to faster growth and more brilliant colors. Ultraviolet sterilizers are often used in aquaria to help control unwanted microorganisms in the water. UV radiation also ensures that exposed pathogens cannot reproduce, thus decreasing the likelihood of a disease outbreak in an aquarium. Despite of these benefits, the ill-effects of radiations cannot be ruled out. Ultraviolet Radiation-induced DNA Damage is seen in the skin of the Platyfish Xiphophorus. Higher radiation doses may cause the gastrointestinal syndrome that leads to defects of the intestinal mucosa barrier with successive contamination of musculature. Exposure to UV radiation can kill the fish and induce sublethal effects in embryos, larvae and adults. The change in skin includes irregularity of skin surface, epidermal oedema, necrosis etc. Irradiation may badly influence the textural attributes of fish muscle. (author)

  4. Commercial production of fish meal from fish waste

    Eyo, A.A.

    1987-01-01

    The importance of fish meal production as a means of reducing fish waste currently being experienced in the fisheries subsector is discussed. Cost estimate for Nigeria establishing a fish meal manufacturing plant and suggestions on rational execution of the project are presented. If properly located and well managed, the project will serve to convert fish waste to cash in the industrial fishery

  5. Collective Motion of Robotic Fish Synchronized with Antiphases

    Wang, Chen; Cao, Ming; Xie, Guangming

    2011-01-01

    The study of design principles for individual robotic fish can be traced back to at least the early 1990’s. More recently, different central pattern generator (CPG) models have been utilized to control the locomotions of robotic fish and some results have been reported to use proper sensing and plan

  6. Hood River and Pelton Ladder Evaluation Studies, 2008 Annual Report : October 2007 - September 2008.

    Reagan, Robert E.; Olsen, Erik A. [Oregon Department of Fish and Wildlife

    2009-09-28

    This report summarizes the life history and production data collected in the Hood River subbasin during FY 2008. Included is a summary of jack and adult life history data collected at the Powerdale Dam trap on seventeen complete run years of winter steelhead, spring and fall chinook salmon, and coho salmon, and on fifteen complete run years of summer steelhead. Also included are summaries of (1) the hatchery winter steelhead broodstock collection program; (2) hatchery production releases in the Hood River subbasin; (3) subbasin wild summer and winter steelhead smolt production, (4) numbers of hatchery summer and winter steelhead smolts leaving the subbasin; (5) smolt migration timing past Bonneville Dam, (6) wild and hatchery steelhead smolt-to-adult survival rates; (7) wild summer and winter steelhead egg to smolt survival rates; and (8) streamflow at selected locations in the Hood River subbasin. Data will be used in part to (1) evaluate the HRPP relative to its impact on indigenous populations of resident and anadromous salmonids (see Ardren Draft), (2) evaluate the HRPP's progress towards achieving the biological fish objectives defined in the Hood River Subbasin Plan (Coccoli 2004) and the Revised Master Plan for the Hood River Production Program (HDR|FishPro, ODFW, and CTWSRO 2008), (3) refine spawner escapement objectives to more accurately reflect subbasin carrying capacity, and (4) refine estimates of subbasin smolt production capacity to more accurately reflect current and potential subbasin carrying capacity.

  7. Identifying Fishes through DNA Barcodes and Microarrays.

    Marc Kochzius

    Full Text Available BACKGROUND: International fish trade reached an import value of 62.8 billion Euro in 2006, of which 44.6% are covered by the European Union. Species identification is a key problem throughout the life cycle of fishes: from eggs and larvae to adults in fisheries research and control, as well as processed fish products in consumer protection. METHODOLOGY/PRINCIPAL FINDINGS: This study aims to evaluate the applicability of the three mitochondrial genes 16S rRNA (16S, cytochrome b (cyt b, and cytochrome oxidase subunit I (COI for the identification of 50 European marine fish species by combining techniques of "DNA barcoding" and microarrays. In a DNA barcoding approach, neighbour Joining (NJ phylogenetic trees of 369 16S, 212 cyt b, and 447 COI sequences indicated that cyt b and COI are suitable for unambiguous identification, whereas 16S failed to discriminate closely related flatfish and gurnard species. In course of probe design for DNA microarray development, each of the markers yielded a high number of potentially species-specific probes in silico, although many of them were rejected based on microarray hybridisation experiments. None of the markers provided probes to discriminate the sibling flatfish and gurnard species. However, since 16S-probes were less negatively influenced by the "position of label" effect and showed the lowest rejection rate and the highest mean signal intensity, 16S is more suitable for DNA microarray probe design than cty b and COI. The large portion of rejected COI-probes after hybridisation experiments (>90% renders the DNA barcoding marker as rather unsuitable for this high-throughput technology. CONCLUSIONS/SIGNIFICANCE: Based on these data, a DNA microarray containing 64 functional oligonucleotide probes for the identification of 30 out of the 50 fish species investigated was developed. It represents the next step towards an automated and easy-to-handle method to identify fish, ichthyoplankton, and fish products.

  8. Fishing Community Profiles

    National Oceanic and Atmospheric Administration, Department of Commerce — To enable fisheries managers to comply with National Standard 8 (NS8), NMFS social scientists around the nation are preparing fishing community profiles that...

  9. Logy Bay Fishing Settlement

    S H Parsons and Sons

    2003-01-01

    202 x 151 mm. Showing the small inlet with moored rowing boats and rough wooden shacks built on the cliffside. Lying about seven miles from St. John's, Logy Bay was used as a summertime fishing station.

  10. SIS - Fish Assessment

    National Oceanic and Atmospheric Administration, Department of Commerce — The Fish Assessment data set within the Species Information System (SIS) constraints information related to fishery stock assessments, including assessment...

  11. Poisoning - fish and shellfish

    In Ciguatera poisoning, the poisonous ingredient is ciguatoxin. This is a poison made in small amounts by certain algae and algae-like organisms called dinoflagellates. Small fish that eat the algae ...

  12. Fish germ cells

    2010-01-01

    Fish, like many other animals, have two major cell lineages, namely the germline and soma. The germ-soma separation is one of the earliest events of embryonic development. Germ cells can be specifically labeled and isolated for culture and transplan-tation, providing tools for reproduction of endangered species in close relatives, such as surrogate production of trout in salmon. Haploid cell cultures, such as medaka haploid embryonic stem cells have recently been obtained, which are capable of mimicking sperm to produce fertile offspring, upon nuclear being directly transferred into normal eggs. Such fish originated from a mosaic oocyte that had a haploid meiotic nucleus and a transplanted haploid mitotic cell culture nucleus. The first semi-cloned fish is Holly. Here we review the current status and future directions of understanding and manipulating fish germ cells in basic research and reproductive technology.

  13. Tuning of the electronic and photophysical properties of ladder-type quaterphenyl by selective methylene-bridge fluorination.

    Dänekamp, Benedikt; Kobin, Björn; Bhattacharyya, Santanu; Hecht, Stefan; Milián-Medina, Begoña; Gierschner, Johannes

    2016-06-28

    The photophysics (spectral positions, band shapes, fluorescence quantum yields and lifetimes) of a series of fluorinated ladder type quaterphenyls L4P and L4P-Fn (n = 2, 4, 6) depend strongly on the degree and position of fluorine, despite the fact that substitution is not performed in the rings but only in methylene-bridges. This is driven by subtle differences in the molecular orbitals (MOs) participating in the electronic transitions, and in the vibronic pattern of the S0 and S1 electronic states as revealed by (TD)DFT calculations. Solid state spectra for n = 0, 2, 4 are similar to those of solution due to small intermolecular interactions as revealed by combined X-ray and (TD)DFT analysis. PMID:27263988

  14. Ab initio downfolding study of the iron-based ladder superconductor BaFe2S3

    Arita, Ryotaro; Ikeda, Hiroaki; Sakai, Shiro; Suzuki, Michi-To

    2015-08-01

    Motivated by the recent discovery of superconductivity in the iron-based ladder compound BaFe2S3 under high pressure, we derive low-energy effective Hamiltonians from first principles. We show that the complex band structure around the Fermi level is represented only by the Fe 3 dx z (mixed with 3 dx y ) and 3 dx2-y2 orbitals. The characteristic band degeneracy allows us to construct a four-band model with the band unfolding approach. We also estimate the interaction parameters and show that the system is more correlated than the 1111 family of iron-based superconductors. Provided the superconductivity is mediated by spin fluctuations, the 3 dx z -like band plays an essential role, and the gap function changes its sign between the Fermi surface around the Γ point and that around the Brillouin-zone boundary.

  15. Manifestation of anomalous Floquet states with longevity in dynamic fractional Stark ladder with high AC electric fields

    Nemoto, Yuya; Ohno, Fumitaka; Maeshima, Nobuya; Hino, Ken-ichi

    2016-09-01

    We examine a resonance structure of Floquet state in dynamic fractional Stark ladder (DFSL) realized in biased semiconductor superlattices driven by a terahertz cw laser on the basis of the R-matrix Floquet theory. To do this, we calculate an excess density of state ρ (ex)(E) corresponding to lifetime of the Floquet state with a fractional matching ratio η, where η is the ratio of a Bloch frequency ΩB to a laser frequency ω, namely, η =ΩB / ω. The results for η = 3 / 2 demonstrate the appearance of discernibly large peaks associated with Floquet states with longevity in a region of relatively high laser-intensity. The underlying physics is discussed in terms of an analytical expression of ρ (ex)(E) and the associated Green function in which ponderomotive couplings are included in a non-perturbative way.

  16. Generation of non-classical correlated photon pairs via a ladder-type atomic configuration: theory and experiment.

    Ding, Dong-Sheng; Zhou, Zhi-Yuan; Shi, Bao-Sen; Zou, Xu-Bo; Guo, Guang-Can

    2012-05-01

    We experimentally generate a non-classical correlated two-color photon pair at 780 and 1529.4 nm in a ladder-type configuration using a hot 85Rb atomic vapor with the production rate of ~10(7)/s. The non-classical correlation between these two photons is demonstrated by strong violation of Cauchy-Schwarz inequality by the factor R = 48 ± 12. Besides, we experimentally investigate the relations between the correlation and some important experimental parameters such as the single-photon detuning, the powers of pumps. We also make a theoretical analysis in detail and the theoretical predictions are in reasonable agreement with our experimental results. PMID:22565763

  17. Ground states of a Bose–Hubbard ladder in an artificial magnetic field: field-theoretical approach

    We consider a Bose–Hubbard ladder subject to an artificial magnetic flux and discuss its different ground states, their physical properties, and the quantum phase transitions between them. A low-energy effective field theory is derived, in the two distinct regimes of a small and large magnetic flux, using a bosonization technique starting from the weak-coupling limit. Based on this effective field theory, the ground-state phase diagram at a filling of one particle per site is investigated for a small flux and for a flux equal to π per plaquette. For π-flux, this analysis reveals a tricritical point, which has been overlooked in previous studies. In addition, the Mott insulating state at a small magnetic flux is found to display Meissner currents. (paper)

  18. Welfare in farmed fish

    Damsgård, Børge; Juell, Jon-Erik; Braastad, Bjarne Olai

    2006-01-01

    The interest of fish welfare is increasing, both in Norway and internationally, leading to an increasing need for scientific knowledge about basic and applied questions related to how farmed fish are produced. The strategic institute programme (SIP) ”Welfare in farmed fish” was financed by the Research Council of Norway, for the five years period from 1 January 2001 to 31 December 2005. The core partners in the SIP were the Norwegian Institute of Fisheries and Aquaculture Research (Fiskerifor...

  19. Fish Stem Cell Cultures

    Ni Hong, Zhendong Li, Yunhan Hong

    2011-01-01

    Stem cells have the potential for self-renewal and differentiation. First stem cell cultures were derived 30 years ago from early developing mouse embryos. These are pluripotent embryonic stem (ES) cells. Efforts towards ES cell derivation have been attempted in other mammalian and non-mammalian species. Work with stem cell culture in fish started 20 years ago. Laboratory fish species, in particular zebrafish and medaka, have been the focus of research towards stem cell cultures. Medaka is th...

  20. Improved fish smoking: Ghana

    2001-01-01

    Fish is an important source of food and income to many people in the developing world. In Africa, some 5 percent of the population, about 35 million people, depend wholly or partly on the fisheries sector, mostly artisanal fisheries, for their livelihood. Various traditional methods are employed to preserve and process fish for consumption and storage. These include smoking, drying, salting, frying and fermenting and various combinations of these. In Ghana, smoking is the mo...

  1. Disorder effects in the S=1 antiferromagnetic spin ladder CaV{sub 2}O{sub 4}

    Guitarra, S.R. [Colegio de Ciencias e Ingeniería, Universidad San Francisco de Quito, Quito (Ecuador); Caneiro, A. [Instituto Balseiro - Centro Atómico Bariloche, 8400 Bariloche (Argentina); Niebieskikwiat, D., E-mail: dniebieskikwiat@usfq.edu.ec [Colegio de Ciencias e Ingeniería, Universidad San Francisco de Quito, Quito (Ecuador)

    2015-10-15

    We study the physical properties of the antiferromagnetic spin ladder CaV{sub 2}O{sub 4} (CVO) and the Y-doped related compound Ca{sub 0.9}Y{sub 0.1}V{sub 2}O{sub 4}. In the latter, X-ray diffraction demonstrates the segregation of a small amount of a vanadium–perovskite impurity phase, leading to the formation of V vacancies within the main CVO-type structure. The 1D character of this calcium–vanadite enhances the influence of the vacancies on the electric and magnetic properties of Ca{sub 0.9}Y{sub 0.1}V{sub 2}O{sub 4}. Electrical transport is characterized by a variable-range hopping mechanism determined by the charging energy of nm-sized segments of V chains delimited by V vacancies, i.e. a Coulomb gap is formed at the Fermi level. These vacancies also locally affect the magnetic correlations, breaking the long-range AFM order observed in CaV{sub 2}O{sub 4} and producing exchange bias when the Y-doped sample is cooled with an applied magnetic field. - Highlights: • We study disorder effects in the quasi-1D antiferromagnetic spin ladder CaV{sub 2}O{sub 4}. • V vacancies in CaV{sub 2}O{sub 4} lead to variable-range hopping electrical transport. • The charging energy of nm-sized V chains determine the transport mechanism exponents. • V vacancies break the long-range AFM order of CaV{sub 2}O{sub 4}. • Local magnetic correlations in the vicinity of the defects produce exchange bias.

  2. Modeling Fish Growth in Low Dissolved Oxygen

    Neilan, Rachael Miller

    2013-01-01

    This article describes a computational project designed for undergraduate students as an introduction to mathematical modeling. Students use an ordinary differential equation to describe fish weight and assume the instantaneous growth rate depends on the concentration of dissolved oxygen. Published laboratory experiments suggest that continuous…

  3. Predator Avoidance in Extremophile Fish

    Martin Plath

    2013-02-01

    Full Text Available Extreme habitats are often characterized by reduced predation pressures, thus representing refuges for the inhabiting species. The present study was designed to investigate predator avoidance of extremophile populations of Poecilia mexicana and P. sulphuraria that either live in hydrogen sulfide-rich (sulfidic springs or cave habitats, both of which are known to have impoverished piscine predator regimes. Focal fishes that inhabited sulfidic springs showed slightly weaker avoidance reactions when presented with several naturally occurring predatory cichlids, but strongest differences to populations from non-sulfidic habitats were found in a decreased shoaling tendency with non-predatory swordtail (Xiphophorus hellerii females. When comparing avoidance reactions between P. mexicana from a sulfidic cave (Cueva del Azufre and the adjacent sulfidic surface creek (El Azufre, we found only slight differences in predator avoidance, but surface fish reacted much more strongly to the non-predatory cichlid Vieja bifasciata. Our third experiment was designed to disentangle learned from innate effects of predator recognition. We compared laboratory-reared (i.e., predator-naïve and wild-caught (i.e., predator-experienced individuals of P. mexicana from a non-sulfidic river and found no differences in their reaction towards the presented predators. Overall, our results indicate (1 that predator avoidance is still functional in extremophile Poecilia spp. and (2 that predator recognition and avoidance reactions have a strong genetic basis.

  4. Are fish eaters healthier and do they consume less health-care resources?

    Hostenkamp, Gisela; Sørensen, Jan

    2010-01-01

    Objective: Regular dietary intake of fish is associated with reduced risk of developing cardiovascular and other chronic diseases, and may improve general well-being. If fish eaters are healthier, they may use fewer health-care resources. The present study aimed to describe the reported intake of...... fish and fish products in a Danish general population, and to investigate whether fish consumption is associated with generic measures of self-reported health and consumption of health-care resources. Design: Data on eating patterns and health status for 3422 Danish adults were obtained by telephone...... interview in the Funen County Health Survey. These data were merged with individual-level register data on health-care utilisation. Survey respondents were categorised into those consuming fish at least once weekly (fish eaters) and those consuming fish less frequently (non-fish eaters). Results: People who...

  5. Sanitation, fish handling and artisanal fish processing within fishing communities: socio-cultural influences

    Odongkara, K.O.; Kyangwa, I.

    2005-01-01

    postive transformation of the fisheries sector in Uganda has of recent been scatted by failure to mountain fish quality and safety,akey prerequiste for retaining and gaining fish markets. The social cultural study established the extent to which social cutural practices had affected the levels and the use of sanitation facilities,fish handling facilities and artisanal fish processing techniques and the factors that influenced these practices in the fishing communities of lake victoria. ...

  6. When a Fish is a Fish: The Economic Impacts of Escaped Farmed Fish

    Yajie Liu; Jon Olaf Olaussen; Anders Skonhoft

    2011-01-01

    The escape of cultured fish from a marine aquaculture facility is a type of biological invasion that may lead to a variety of potential ecological and economic effects on native fish. This paper develops a general invasive species impact model to capture explicitly both the ecological and economic effects of invasive species, especially escaped farmed fish, on native stocks and harvests. First, the possible effects of escaped farmed fish on the growth and stock size of a native fish are exami...

  7. Fish robotics and hydrodynamics

    Lauder, George

    2010-11-01

    Studying the fluid dynamics of locomotion in freely-swimming fishes is challenging due to difficulties in controlling fish behavior. To provide better control over fish-like propulsive systems we have constructed a variety of fish-like robotic test platforms that range from highly biomimetic models of fins, to simple physical models of body movements during aquatic locomotion. First, we have constructed a series of biorobotic models of fish pectoral fins with 5 fin rays that allow detailed study of fin motion, forces, and fluid dynamics associated with fin-based locomotion. We find that by tuning fin ray stiffness and the imposed motion program we can produce thrust both on the fin outstroke and instroke. Second, we are using a robotic flapping foil system to study the self-propulsion of flexible plastic foils of varying stiffness, length, and trailing edge shape as a means of investigating the fluid dynamic effect of simple changes in the properties of undulating bodies moving through water. We find unexpected non-linear stiffness-dependent effects of changing foil length on self-propelled speed, and as well as significant effects of trailing edge shape on foil swimming speed.

  8. Freshwater and fish

    Severe radioactive contamination of the freshwater environment could have serious consequences for both drinking water and fish. Most of the Nordic countries have an abundance of freshwater lakes and rivers. Finland alone has about 56,000 lakes, each with a surface area of 1 hectare or more. Nearly 10% of Finland's surface is covered with lakes and rivers. In Sweden, about 9% of the surface area is freshwater, in Norway about 5%, and in Denmark only about 2%. Freshwater plays a minor role in Iceland, but even there numerous rivers discharge from the volcanic soils to the Ocean. Cs-137 and 90Sr are likely to be the most important radionuclides with respect to long term radioactive contamination of freshwater. If radioactive deposition occurs in the absence of snow and ice radionuclides will contaminate the surface water directly and may rapidly enter the aquatic food chain. Fish which eat contaminated plankton become contaminated almost immediately. Deposition during summer increases the transfer for radionuclides to fish since fish metabolism is faster during the warm season. During the cold period, fish metabolism is slow and thus uptake and excretion of radiocaesium are also slow. (EG)

  9. ChillFish: A Respiration Game for Children with ADHD

    Sonne, Tobias; Jensen, Mads Møller

    2016-01-01

    Breathing exercises can help children with ADHD control their stress level, but it can be hard for a child to sustain attention throughout such an exercise. In this paper, we present ChillFish, a breath-controlled biofeedback game designed in collaboration with ADHD professionals to investigate the possibilities of combining breathing exercises and game design. Based on a pilot study with 16 adults, we found that playing ChillFish had a positive effect, helping the participants to reach a rel...

  10. 多控制面机器鱼结构设计及尾鳍动力学数学模型构建%Dynamic Math Mode Building of Tail Fin and Structure Design of Control Surface Bionic Robotic-fish

    王卫兵; 杨红伟; 晁贯良; 牛健文

    2012-01-01

    The structure of control surface biomimetic robotic-fish was designed, which included tail fin, pectoral fin, pelvic fin, and pinna dorsalis combining propulsion. On the basis of the characteristic of structure, the swimming balance of bionic robotic-fish was achieved by controlling the each part of propulsion system. The dynamic math model of tail fin of four-joint robotic-fish was built using the theory of planar wave plank and Lagrange equation. The academic base for the relation of the kinetic parameters of robotic-fish is prepared by the model.%设计了多控制面仿生机器鱼结构,包括尾鳍、胸鳍、腹鳍、背鳍的联合推进.根据其结构特点,对机器鱼推进系统的各关节进行控制从而实现仿生机器鱼前进的平衡性,主要利用二维波动板理论和Lagrange方程建立了四关节仿生机器鱼尾鳍的动力学数学模型,该模型建立了仿生机器鱼各个运动参数之间的关系.

  11. Towards direct numerical simulation of freely swimming fish.

    Curet, Oscar; Patankar, Neelesh; Maciver, Malcolm

    2006-11-01

    Swimming mechanisms employed by fish are currently inspiring unique underwater vehicles and robotic devices as well as basic science research into the neural control of movement. Key engineering issues include propulsion efficiency, precise motion control and maneuverability. A numerical scheme that simulates the motion of freely swimming fish will be a valuable design and research tool. We are working towards this goal. In particular we are interested in simulating the motion of a gymnotiform fish that swims by producing undulations of a ventral ribbon fin while keeping its body rigid. We model the fish as a rigid body with an attached undulating membrane. In our numerical scheme the key idea is to assume that the entire fluid-fish domain is a fluid. Then we impose two constraints: the first requires that the fluid in the region occupied by the fish body moves rigidly (a fictitious domain approach), and the second requires that the fluid at the location of the fin has the traveling wave velocity of the fin (an immersed boundary approach). Given the traveling wave form of the fin, the objective is for the numerical scheme to give the swimming velocity of the fish by solving the coupled fluid-fish problem. We will present results for the forces generated by a fin attached to a fixed body and preliminary results for freely swimming fish.

  12. Humane harvesting and slaughter of farmed fish.

    Lines, J A; Spence, J

    2014-04-01

    The overwhelming majority of farmed fish produced throughout the world are killed with little or no consideration for their welfare. Fasting periods can be excessive, transport stressful and killing inhumane. At the time of writing, the salmon industry is the only sector in which consideration of the welfare of the fish at slaughter has resulted in significant improvements throughout most of the industry. There are signs of interest in the use of more humane slaughter methods for some other fish species. This is mostly initiated by the demand for higher standards from European fish retailers. For most species, the humane killing options are limited to percussive stunning and electrical stunning. However, even these methods can have a poor welfare outcome if insufficient consideration is given to the needs of the fish or if the equipment has not been properly designed. The use of food-grade anaesthetics to assist with the harvest has significant potential for improving welfare and their wider use should be investigated further. PMID:25000798

  13. The welfare of fish.

    Iwama, George K

    2007-05-01

    Our interactions with fish cover a wide range of activities including enjoying them as pets to consuming them as food. I propose that we confine the consideration of the welfare of fish to their physiology, and not join the discussion on whether fish can feel pain and suffering, as humans. A significant proportion of the papers on animal welfare center on whether non-human animals can feel pain, and suffer as humans. This is a question that never can be answered unequivocally. The premise of the present paper is that we have an ethical responsibility to respect the life and wellbeing of all organisms. Thus, we should concentrate on the behavioural, physiological, and cellular indicators of their well-being and attempt to minimize a state of stress in the animals that we have in our care or influence. PMID:17578254

  14. Fish Hematology and Associated Disorders.

    Grant, Krystan R

    2015-09-01

    Fish health is a growing concern as pets, education, and aquaculture evolves. For the veterinary staff, fish handling, diagnostics, medicine, and surgery may require specialized training and equipment in comparison with terrestrial and arboreal animals, simply because of their aquatic nature and diversity. Fish hematology is one diagnostic tool that may not require additional equipment, may be inexpensive, and provide useful information in guiding treatment options. Challenges involving hematology may include handling and restraint, venipuncture, evaluation, and interpretation. In this article, strategies for these challenges are discussed for teleost (bony fish) and elasmobranch (cartilaginous fish) fish types. PMID:26297413

  15. Fish Hatchery Management in Nigeria

    J.A. Akankali

    2011-04-01

    Full Text Available Fish hatchery management is efficient tool in intensive fish culture. The vital requirements of fish hatchery, hatchery construction, concrete tank construction, nursery, rearing and production ponds, fish seed hatchery, hormone in fish spawning, hypophysation, compounds used for induced breeding, hormone administration, spawning and rearing, steps in artificial propagation, hatchery management, nursery management are basic elements in effective hatchery management. The article reviews these vital elements to re-awaken fish farmers, Fisheries students private and public sectors in the formulation of fisheries policies.

  16. Jurassic fishes of Gondwana

    Adriana López-Arbarello

    2008-12-01

    Full Text Available The Jurassic is an important period for understanding the origin of modern fish faunas, since it saw the first radiation - and in some cases the origin - of most modern groups. In chondrichthyans, neoselachian sharks and rays diversified during this time. In actinopterygians, the neopterygians, and among them the teleosts, experienced an important radiation, which led to the appearance of several of the modern teleosts groups. In the sarcopterygians, dipnoans and actinistians approached their current forms. However, the Jurassic fossil record of fishes is strongly biased towards the Northern Hemisphere. The only notable Early Jurassic fish fauna from Gondwana is that of the Kota Formation of India. For the Middle Jurassic, the most important Gondwanan fish faunas are those of the Aalenian-Bathonian Stanleyville Beds of the Democratic Republic of Congo, in which a distinct freshwater and a marine fauna are found. In the Late Jurassic, the Gondwanan record is slightly better, with important marine faunas being known from the Oxfordian Quebrada del Profeta in Chile and the Tithonian Vaca Muerta Formation of Argentina. Freshwater faunas have been described from the Tithonian Talbragar Beds of eastern Australia and the Tithonian Cañadón Calcáreo Formation of Argentina. The taxonomic composition of the known marine actinopterygian faunas of Gondwana is in general agreement with faunas of the Northern Hemisphere. However, the Jurassic fish record from Gondwana is highly incomplete both stratigraphically and geographically, and most faunas are in need of revision, further hampering an interpretation of Jurassic fish evolution in the Southern Hemisphere.

  17. Fish Stem Cell Cultures

    Ni Hong, Zhendong Li, Yunhan Hong

    2011-01-01

    Full Text Available Stem cells have the potential for self-renewal and differentiation. First stem cell cultures were derived 30 years ago from early developing mouse embryos. These are pluripotent embryonic stem (ES cells. Efforts towards ES cell derivation have been attempted in other mammalian and non-mammalian species. Work with stem cell culture in fish started 20 years ago. Laboratory fish species, in particular zebrafish and medaka, have been the focus of research towards stem cell cultures. Medaka is the second organism that generated ES cells and the first that gave rise to a spermatogonial stem cell line capable of test-tube sperm production. Most recently, the first haploid stem cells capable of producing whole animals have also been generated from medaka. ES-like cells have been reported also in zebrafish and several marine species. Attempts for germline transmission of ES cell cultures and gene targeting have been reported in zebrafish. Recent years have witnessed the progress in markers and procedures for ES cell characterization. These include the identification of fish homologs/paralogs of mammalian pluripotency genes and parameters for optimal chimera formation. In addition, fish germ cell cultures and transplantation have attracted considerable interest for germline transmission and surrogate production. Haploid ES cell nuclear transfer has proven in medaka the feasibility of semi-cloning as a novel assisted reproductive technology. In this special issue on “Fish Stem Cells and Nuclear Transfer”, we will focus our review on medaka to illustrate the current status and perspective of fish stem cells in research and application. We will also mention semi-cloning as a new development to conventional nuclear transfer.

  18. Fish remains and humankind

    Andrew K G Jones

    1997-08-01

    Full Text Available The four papers in this issue represent a trawl of the reports presented to the Fourth meeting of the International Council for Archaeozoology (ICAZ Fish Remains Working Group, which met at the University of York in 1987. The conference discussed material from many parts of the world - from Australasia to the north-west coast of America - and many eras, ranging in date from the early Pleistocene to the 1980s. It demonstrated both the variety of work being carried out and the growing interest in ancient fish remains. Internet Archaeology plans to publish other batches of papers from this conference. These reports will demonstrate the effort being made to distinguish between assemblages of fish remains which have been deposited by people and those which occur in ancient deposits as a result of the action of other agents. To investigate this area, experiments with modern material and observations of naturally occurring fish bone assemblages are supplemented with detailed analysis of ancient and modern fish remains. The papers published here illustrate the breadth of research into osteology, biogeography, documentary research, and the practicalities of recovering fish remains. Read, digest and enjoy them! Using the Internet for publishing research papers is not only ecologically sound (saving paper, etc. it disseminates scholarship to anyone anywhere on the planet with access to what is gradually becoming necessary technology in the late 20th century. Hopefully, future groups of papers will include video and audio material recorded at the conference, and so enable those who could not attend to gain further insights into the meeting and the scholarship underpinning this area of research.

  19. Electric fish as natural models for technical sensor systems

    von der Emde, Gerhard; Bousack, Herbert; Huck, Christina; Mayekar, Kavita; Pabst, Michael; Zhang, Yi

    2009-05-01

    Instead of vision, many animals use alternative senses for object detection. Weakly electric fish employ "active electrolocation", during which they discharge an electric organ emitting electrical current pulses (electric organ discharges, EOD). Local EODs are sensed by electroreceptors in the fish's skin, which respond to changes of the signal caused by nearby objects. Fish can gain information about attributes of an object, such as size, shape, distance, and complex impedance. When close to the fish, each object projects an 'electric image' onto the fish's skin. In order to get information about an object, the fish has to analyze the object's electric image by sampling its voltage distribution with the electroreceptors. We now know a great deal about the mechanisms the fish use to gain information about objects in their environment. Inspired by the remarkable capabilities of weakly electric fish in detecting and recognizing objects with their electric sense, we are designing technical sensor systems that can solve similar sensing problems. We applied the principles of active electrolocation to devices that produce electrical current pulses in water and simultaneously sense local current densities. Depending on the specific task, sensors can be designed which detect an object, localize it in space, determine its distance, and measure certain object properties such as material properties, thickness, or material faults. We present first experiments and FEM simulations on the optimal sensor arrangement regarding the sensor requirements e. g. localization of objects or distance measurements. Different methods of the sensor read-out and signal processing are compared.

  20. Fish-robot interactions in a free-swimming environment: Effects of speed and configuration of robots on live fish

    Butail, Sachit; Polverino, Giovanni; Phamduy, Paul; Del Sette, Fausto; Porfiri, Maurizio

    2014-03-01

    We explore fish-robot interactions in a comprehensive set of experiments designed to highlight the effects of speed and configuration of bioinspired robots on live zebrafish. The robot design and movement is inspired by salient features of attraction in zebrafish and includes enhanced coloration, aspect ratio of a fertile female, and carangiform/subcarangiformlocomotion. The robots are autonomously controlled to swim in circular trajectories in the presence of live fish. Our results indicate that robot configuration significantly affects both the fish distance to the robots and the time spent near them.