WorldWideScience

Sample records for assisting downstream migrating

  1. Turbulence Investigation and Reproduction for Assisting Downstream Migrating Juvenile Salmonids, Part I of II, 2001-2002 Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Hotchkiss, Rollin H. (Washington State University, Department of Civil and Environmental Engineers, Albrook Hydraulics Laboratory)

    2002-12-01

    Turbulence in gravel bed rivers plays a critical role in most stream processes including contaminant and nutrient transport, aquatic habitat selection, and natural channel design. While most hydraulic designs and fluid models are based on bulk velocity, migrating juvenile salmon experience and react to the temporally varied turbulent fluctuations. Without properly understanding and accounting for the continuous turbulent motions proper fishway design and guidance are impossible. Matching temporally varied flow to fish reactions is the key to guiding juvenile salmonids to safe passageways. While the ideal solution to fish guidance design would be to use specific fluid action-fish reaction mechanisms, such concrete cause and effect relations have not been established. One way to approach the problem of guidance is to hypothesize that in an environment lacking obvious bulk flow cues (like the reservoir environment), turbulent flow conditions similar to those experienced by juvenile salmonids in natural migration corridors will be attractive to juvenile salmonids. Proof of this hypothesis requires three steps: (1) gathering data on turbulence characteristics in natural migration corridors, (2) reproduction of the turbulence parameters in a controlled environment, and (3) testing the reproduced turbulence on actively migrating juvenile salmonids for increased passage efficiencies. The results from the third step have not been finalized, therefore this report will focus on understanding turbulent processes in gravel bed rivers and reproduction of turbulence in controlled environments for use in fish passage technologies. The purposes of this report are to (1) present data collected in natural gravel bed rivers, (2) present a simple method for reproduction of appropriate turbulence levels in a controlled environment, (3) compare these results to those from one prototype surface collector (PSC), and (4) discuss the implications on fish passage design.

  2. Turbulence investigation and reproduction for assisting downstream migrating juvenile salmonids, Part II of II: Effects of induced turbulence on behavior of juvenile salmon, 2001-2005 final report

    Science.gov (United States)

    Perry, R.; Farley , M.; Hansen, G.; Morse , J.; Rondorf, D.

    2005-01-01

    Passage through dams is a major source of mortality of anadromous juvenile salmonids because some populations must negotiate up to eight dams in Columbia and Snake rivers. Dams cause direct mortality when fish pass through turbines, but dams may also cause indirect mortality by altering migration conditions in rivers. Forebays immediately upstream of dams have decreased the water velocity of rivers and may contribute substantially to the total migration delay of juvenile salmonids. Recently, Coutant (2001a) suggested that in addition to low water velocities, lack of natural turbulence may contribute to migration delay by causing fish to lose directional cues. Coutant (2001a) further hypothesized that restoring turbulence in dam forebays may reduce migration delay by providing directional cues that allow fish to find passage routes more quickly (Coutant 2001a). Although field experiments have yielded proof of the concept of using induced turbulence to guide fish to safe passage routes, little is known about mechanisms actually causing behavioral changes. To test hypotheses about how turbulence influences movement and behavior of migrating juvenile salmonids, we conducted two types of controlled experiments at Cowlitz Falls Dam, Washington. A common measure of migration delay is the elapsed time between arrival at, and passage through, a dam. Therefore, for the first set of experiments, we tested the effect of induced turbulence on the elapsed time needed for fish to traverse through a raceway and pass over a weir at its downstream end (time trial experiment). If turbulence helps guide fish to passage routes, then fish should pass through the raceway quicker in the presence of appropriately scaled and directed turbulent cues. Second, little is known about how the physical properties of water movement provide directional cues to migrating juvenile salmonids. To examine the feasibility of guiding fish with turbulence, we tested whether directed turbulence could guide

  3. Lateral and vertical distribution of downstream migrating juvenile sea lamprey

    Science.gov (United States)

    Sotola, V. Alex; Miehls, Scott M.; Simard, Lee G.; Marsden, J. Ellen

    2018-01-01

    Sea lamprey is considered an invasive and nuisance species in the Laurentian Great Lakes, Lake Champlain, and the Finger Lakes of New York and is a major focus of control efforts. Currently, management practices focus on limiting the area of infestation using barriers to block migratory adults, and lampricides to kill ammocoetes in infested tributaries. No control efforts currently target the downstream-migrating post-metamorphic life stage which could provide another management opportunity. In order to apply control methods to this life stage, a better understanding of their downstream movement patterns is needed. To quantify spatial distribution of downstream migrants, we deployed fyke and drift nets laterally and vertically across the stream channel in two tributaries of Lake Champlain. Sea lamprey was not randomly distributed across the stream width and lateral distribution showed a significant association with discharge. Results indicated that juvenile sea lamprey is most likely to be present in the thalweg and at midwater depths of the stream channel. Further, a majority of the catch occurred during high flow events, suggesting an increase in downstream movement activity when water levels are higher than base flow. Discharge and flow are strong predictors of the distribution of out-migrating sea lamprey, thus managers will need to either target capture efforts in high discharge areas of streams or develop means to guide sea lamprey away from these areas.

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

    International Nuclear Information System (INIS)

    Mih, W.C.

    1991-01-01

    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

  5. Wash functions downstream of Rho1 GTPase in a subset of Drosophila immune cell developmental migrations

    Science.gov (United States)

    Verboon, Jeffrey M.; Rahe, Travis K.; Rodriguez-Mesa, Evelyn; Parkhurst, Susan M.

    2015-01-01

    Drosophila immune cells, the hemocytes, undergo four stereotypical developmental migrations to populate the embryo, where they provide immune reconnoitering, as well as a number of non–immune-related functions necessary for proper embryogenesis. Here, we describe a role for Rho1 in one of these developmental migrations in which posteriorly located hemocytes migrate toward the head. This migration requires the interaction of Rho1 with its downstream effector Wash, a Wiskott–Aldrich syndrome family protein. Both Wash knockdown and a Rho1 transgene harboring a mutation that prevents Wash binding exhibit the same developmental migratory defect as Rho1 knockdown. Wash activates the Arp2/3 complex, whose activity is needed for this migration, whereas members of the WASH regulatory complex (SWIP, Strumpellin, and CCDC53) are not. Our results suggest a WASH complex–independent signaling pathway to regulate the cytoskeleton during a subset of hemocyte developmental migrations. PMID:25739458

  6. Temporal progression in migratory status and sexual maturation in European silver eels during downstream migration

    NARCIS (Netherlands)

    Palstra, A.P.; Guerrero, M.A.; Klein Breteler, J.G.P.; Thillart, G.E.E.J.M.

    2011-01-01

    The onset of downstream migration of European eels is accompanied by a cessation of feeding and the start of sexual maturation which stresses the link between metabolism and sexual maturation, also suggesting an important role for exercise. Exercise has been tested with eels in swim tunnels and was

  7. T-plastin expression downstream to the calcineurin/NFAT pathway is involved in keratinocyte migration.

    Directory of Open Access Journals (Sweden)

    Cécilia Brun

    Full Text Available Cutaneous wound healing requires keratinocyte proliferation, migration and differentiation to restore the barrier function of the skin. The calcineurin/nuclear factor of activated-T-cell (NFAT signaling pathway has been recently shown to be involved in keratinocyte growth, differentiation and migration. It is induced by an increased intracellular calcium rate and its inhibition results in decreased capacities of keratinocytes to migrate. Nevertheless, the link between calcineurin activation and keratinocyte migration remains unknown. Recently, Orai1, a pore subunit of a store-operated calcium channel that favors calcium influx, was shown to play a critical role to control proliferation and migration of basal keratinocytes. Of interest, the actin-bundling T-plastin is crucial in cell motility through cross-linking to actin filament and its synthesis was shown to be induced by calcium influx and regulated by the calcineurin/NFAT pathway in tumor Sezary cells. We investigated herein the role of the calcineurin/NFAT pathway-dependent T-plastin in keratinocyte migration, by quantifying T-plastin expression in keratinocytes and by analyzing their migration under calcineurin inhibition or knockdown of NFAT2 or T-plastin. We did confirm the role of the calcineurin/NFAT pathway in keratinocyte migration as shown by their decreased capacities to migrate after FK506 treatment or siNFAT2 transfection in both scratching and Boyden assays. The expression of NFAT2 and T-plastin in keratinocytes was decreased under FK506 treatment, suggesting that T-plastin plays a role in keratinocyte migration downstream to the calcineurin/NFAT pathway. Accordingly, siRNA knockdown of T-plastin expression also decreased their migration capacities. Actin lamellipodia formation as well as FAK and β6-integrin expression were also significantly decreased after treatment with FK506 or siRNA, reinforcing that NFAT2-dependent T-plastin expression plays a role in keratinocyte

  8. Principle and design of hatch operation system for fish migrating upstream-downstream of the discharge sill

    Directory of Open Access Journals (Sweden)

    Răzvan G.Voicu

    2016-09-01

    Full Text Available To improve fish migration and restore local lotic ecosystems, it is necessary to consider the various current hydro-construction methods. There have been partial successes in systems that improve fish passage over various obstacles but new approaches that present more efficient solutions and international collaboration among specialists are required. This article deals with European themes of great interest; issues related to interruption of longitudinal connectivity in heavily modified water courses, and improving the ecological status of damaged lotic systems, with the goal of achieving the environmental objectives set forth by the Water Framework Directive 2000/60/EC (WFD and the national legislative framework regarding water policy (which reflects the European directives Water Law no. 107, with subsequent amendments, NT No. / 2006 OM 1163/2007, and discusses the obligation to ensure that construction works protect fish migration to maintain ecological balance in the reservoirs. It is possible to use this system in almost any fish-bearing stream, both upstream and downstream of maximum circulation, which makes the system an excellent solution for assisting and improving migration.

  9. Production of structured lipids: acyl migration during enzymatic interesterification and downstream processing

    DEFF Research Database (Denmark)

    Xu, Xuebing

    1997-01-01

    Production of structured lipids by lipase-catalyzed interesterification attracts great interests recently. Structured lipids are defined, in this article, as triacylglycerols which contain both medium or short chain fatty acids and long chain fatty acids, each groups locating specifically in the sn......-2 position or sn-1,3 positions of glycerol backbone. These kinds of lipids are reported to be promising for both enteral and parenteral nutrition. However, acyl migration occurs in the reaction stage and downstream purification process. This side-reaction causes by-products which are harmful...

  10. Influences of body size and environmental factors on autumn downstream migration of bull trout in the Boise River, Idaho

    Science.gov (United States)

    Monnot, L.; Dunham, J.B.; Hoem, T.; Koetsier, P.

    2008-01-01

    Many fishes migrate extensively through stream networks, yet patterns are commonly described only in terms of the origin and destination of migration (e.g., between natal and feeding habitats). To better understand patterns of migration in bull trout,Salvelinus confluentus we studied the influences of body size (total length [TL]) and environmental factors (stream temperature and discharge) on migrations in the Boise River basin, Idaho. During the autumns of 2001-2003, we tracked the downstream migrations of 174 radio-tagged bull trout ranging in size from 21 to 73 cm TL. The results indicated that large bull trout (>30 cm) were more likely than small fish to migrate rapidly downstream after spawning in headwater streams in early autumn. Large bull trout also had a higher probability of arriving at the current terminus of migration in the system, Arrowrock Reservoir. The rate of migration by small bull trout was more variable and individuals were less likely to move into Arrowrock Reservoir. The rate of downstream migration by all fish was slower when stream discharge was greater. Temperature was not associated with the rate of migration. These findings indicate that fish size and environmentally related changes in behavior have important influences on patterns of migration. In a broader context, these results and other recent work suggest, at least in some cases, that commonly used classifications of migratory behavior may not accurately reflect the full range of behaviors and variability among individuals (or life stages) and environmental conditions. ?? Copyright by the American Fisheries Society 2008.

  11. A reverse signaling pathway downstream of Sema4A controls cell migration via Scrib.

    Science.gov (United States)

    Sun, Tianliang; Yang, Lida; Kaur, Harmandeep; Pestel, Jenny; Looso, Mario; Nolte, Hendrik; Krasel, Cornelius; Heil, Daniel; Krishnan, Ramesh K; Santoni, Marie-Josée; Borg, Jean-Paul; Bünemann, Moritz; Offermanns, Stefan; Swiercz, Jakub M; Worzfeld, Thomas

    2017-01-02

    Semaphorins comprise a large family of ligands that regulate key cellular functions through their receptors, plexins. In this study, we show that the transmembrane semaphorin 4A (Sema4A) can also function as a receptor, rather than a ligand, and transduce signals triggered by the binding of Plexin-B1 through reverse signaling. Functionally, reverse Sema4A signaling regulates the migration of various cancer cells as well as dendritic cells. By combining mass spectrometry analysis with small interfering RNA screening, we identify the polarity protein Scrib as a downstream effector of Sema4A. We further show that binding of Plexin-B1 to Sema4A promotes the interaction of Sema4A with Scrib, thereby removing Scrib from its complex with the Rac/Cdc42 exchange factor βPIX and decreasing the activity of the small guanosine triphosphatase Rac1 and Cdc42. Our data unravel a role for Plexin-B1 as a ligand and Sema4A as a receptor and characterize a reverse signaling pathway downstream of Sema4A, which controls cell migration. © 2017 Sun et al.

  12. Effects of a surface oriented travelling screen and water abstraction practices on downstream migrating Salmonidae smolts in a lowland stream

    DEFF Research Database (Denmark)

    Svendsen, Jon Christian; Aarestrup, Kim; Deacon, Michael G.

    2010-01-01

    Downstream migration of immature salmonids (smolts) may be associated with severe mortalities in anthropogenically altered channels. In Pacific salmon, several investigations have suggested the use of the dominating surface orientation of smolts to improve fish by-pass structures in large and dee...

  13. Growing assisted migration: Synthesis of a climate change adaptation strategy

    Science.gov (United States)

    Mary I. Williams; R. Kasten Dumroese

    2013-01-01

    Assisted migration may be necessary as a climate change adaptation strategy for native plant species that are less adaptive or mobile. Moving plants has been practiced a long time in human history, but movement of species in response to climate change is a new context. First proposed in 1985, assisted migration has gained attention since 2007 as a strategy to prevent...

  14. Protein kinase Cδ signaling downstream of the EGF receptor mediates migration and invasiveness of prostate cancer cells

    International Nuclear Information System (INIS)

    Kharait, Sourabh; Dhir, Rajiv; Lauffenburger, Douglas; Wells, Alan

    2006-01-01

    Tumor progression to the invasive phenotype occurs secondary to upregulated signaling from growth factor receptors that drive key cellular responses like proliferation, migration, and invasion. We hypothesized that Protein kinase Cδ (PKCδ)-mediated transcellular contractility is required for migration and invasion of prostate tumor cells. Two invasive human prostate cancer cell lines, DU145 cells overexpressing wildtype human EGFR (DU145WT) and PC3 cells, were studied. PKCδ is overexpressed in these cells relative to normal prostate epithelial cells, and is activated downstream of EGFR leading to cell motility via modulation of myosin light chain activity. Abrogation of PKCδ using Rottlerin and specific siRNA significantly decreased migration and invasion of both cell lines in vitro. Both PKCδ and phosphorylated PKCδ protein levels were higher in human prostate cancer tissue relative to normal donor prostate as assessed by Western blotting and immunohistochemistry. Thus, we conclude that PKCδ inhibition can limit migration and invasion of prostate cancer cells

  15. Planning the future's forests with assisted migration

    Science.gov (United States)

    Mary I. Williams; R. Kasten Dumroese

    2014-01-01

    Studies show that changes in climate may exceed plant adaptation and migration. The mismatch in rates between climate change and plant adaptation and migration will pose significant challenges for practitioners that select, grow, and outplant native tree species. Native tree species and populations that are planted today must meet the climatic challenges that they will...

  16. Preparing for climate change: Forestry and assisted migration

    Science.gov (United States)

    Mary I. Williams; R. Kasten Dumroese

    2013-01-01

    Although plants have moved across the landscape in response to changing climate for millennia, projections of contemporary climate change suggest that forest tree species and populations will need to migrate faster than their natural ability. Therefore, climate change adaptation strategies, such as assisted migration, have gained attention since 2007. Effective...

  17. Net ground speed of downstream migrating radio-tagged Atlantic salmon ( Salmo salar L.) and brown trout ( Salmo trutta L.) smolts in relation to environmental factors

    DEFF Research Database (Denmark)

    Aarestrup, Kim; Nielsen, C.; Koed, Anders

    2002-01-01

    tagged and released in the Danish River Lilleaa. The downstream migration of the different groups of fish was monitored by manual tracking and by three automatic listening stations. The downstream migration of radio tagged smolts of both species occurred concurrently with their untagged counterparts....... The diel migration pattern of the radio tagged smolts was predominantly nocturnal in both species. Wild sea trout smolt migrated significantly faster than both the F1 trout and the introduced salmon. There was no correlation between net ground speed, gill Na+, K+-ATPase activity or fish length in any...

  18. In vivo relative quantitative proteomics reveals HMGB1 as a downstream mediator of oestrogen-stimulated keratinocyte migration.

    Science.gov (United States)

    Shin, Jung U; Noh, Ji Yeon; Lee, Ju Hee; Lee, Won Jai; Yoo, Jong Shin; Kim, Jin Young; Kim, Hyeran; Jung, Inhee; Jin, Shan; Lee, Kwang Hoon

    2015-06-01

    It is known that oestrogen influences skin wound healing by modulating the inflammatory response, cytokine expression and extracellular matrix deposition; accelerating re-epithelialization; and stimulating angiogenesis. To identify novel proteins associated with effects of oestrogen on keratinocyte, stable isotope labelling by amino acids in cell culture (SILAC)-based mass spectrometry was performed. Using SILAC, quantification of 1085 proteins was achieved. Among these proteins, 60 proteins were upregulated and 32 proteins were downregulated. Among significantly upregulated proteins, high-mobility group protein B1 (HMGB1) has been further evaluated for its role in the effect of oestrogen on keratinocytes. HMGB1 expression was strongly induced in oestrogen-treated keratinocytes in dose- and time-dependent manner. Further, HMGB1 was able to significantly accelerate the rate of HaCaT cell migration. To determine whether HMGB1 is involved in E2-induced HaCaT cell migration, cells were transfected with HMGB1 siRNA. Knockdown of HMGB1 blocked oestrogen-induced keratinocyte migration. Collectively, these experiments demonstrate that HMGB1 is a novel downstream mediator of oestrogen-stimulated keratinocyte migration. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Focal Adhesion Kinase functions as an Akt downstream target in migration of colorectal cancer cells

    Czech Academy of Sciences Publication Activity Database

    Turečková, Jolana; Vojtěchová, Martina; Krausová, Michaela; Šloncová, Eva; Kořínek, Vladimír

    2009-01-01

    Roč. 2, č. 4 (2009), s. 281-290 ISSN 1936-5233 R&D Projects: GA ČR GA204/06/1658; GA MŠk 2B06077 Institutional research plan: CEZ:AV0Z50520514 Keywords : FAK * migration * invasion Subject RIV: EB - Genetics ; Molecular Biology

  20. Electrical guidance efficiency of downstream-migrating juvenile Sea Lamprey decreases with increasing water velocity

    Science.gov (United States)

    Miehls, Scott M.; Johnson, Nicholas; Haro, Alexander

    2017-01-01

    We tested the efficacy of a vertically oriented field of pulsed direct current (VEPDC) created by an array of vertical electrodes for guiding downstream-moving juvenile Sea Lampreys Petromyzon marinus to a bypass channel in an artificial flume at water velocities of 10–50 cm/s. Sea Lampreys were more likely to be captured in the bypass channel than in other sections of the flume regardless of electric field status (on or off) or water velocity. Additionally, Sea Lampreys were more likely to be captured in the bypass channel when the VEPDC was active; however, an interaction between the effects of VEPDC and water velocity was observed, as the likelihood of capture decreased with increases in water velocity. The distribution of Sea Lampreys shifted from right to left across the width of the flume toward the bypass channel when the VEPDC was active at water velocities less than 25 cm/s. The VEPDC appeared to have no effect on Sea Lamprey distribution in the flume at water velocities greater than 25 cm/s. We also conducted separate tests to determine the threshold at which Sea Lampreys would become paralyzed. Individuals were paralyzed at a mean power density of 37.0 µW/cm3. Future research should investigate the ability of juvenile Sea Lampreys to detect electric fields and their specific behavioral responses to electric field characteristics so as to optimize the use of this technology as a nonphysical guidance tool across variable water velocities.

  1. SUGGESTIONS OF SCENARIOS FOR RESTORING LONGITUDINAL CONNECTIVITY TO SUSTAIN FISH FAUNA MIGRATION UPSTREAM AND DOWNSTREAM OF APAHIDA BOTTOM SILL

    Directory of Open Access Journals (Sweden)

    Razvan VOICU

    2016-12-01

    Full Text Available Rivers and their corridors form complex ecosystems that include adjacent land, flora and fauna and the actual courses of water. Given the ecological criteria for prioritizing the rehabilitation of longitudinal continuity of watercourses recommended by the International Commission for Protection of the Danube River (ICPDR (Appendix 1 and starting from the analysis of the Management Plan to ensure longitudinal continuity of watercourses in Some?-Tisa River Area (Annex 9.17.a in BMP – Basin Management Plan there have been proposed several scenarios in order to facilitate fish species migration above the bottom sill from Apahida. The selected case study is focused on the mentioned discharge or bottom sill in Apahida town (hm 985 located 45 m downstream of the bridge located at the intersection of two streets; this bottom sill is 0.8 m high and was built in order to correct the slope, to reduce erosion and to enhance water oxygenation. Currently the bottom sill is supervised by Some?-Tisa River Basin Water Administration, Cluj SGA. One of the important migratory fish species in the study area is the Common Nase (Chondrostoma nasus protected by Bern Convention (Appendix III; barbel (Barbus barbus- rare species, protected Habitats Directive (Annex V,annex 4A of Low nr.462 and Red List of RBDD; bream (Abramis brama bream (Abramis brama - IUCN Red List of Threatened Species. The water catchment area of the Apahida commune in Cluj County blocks migration of various species of migratory fish such as: Common Nase (Chondrostoma nasus protected by the Bern Convention (Appendix III; Barbel (Barbus barbus - rare species, protected Habitats Directive (Annex V, Annex 4A of Low No 462 and Red List of RBDD; Bream (Abramis brama Bream (Abramis brama - IUCN Red List of Threatened Species. To help the three species of fish come the solutions proposed in this article.

  2. Passage of downstream migrant American eels through an airlift-assisted deep bypass

    Science.gov (United States)

    Haro, Alexander J.; Watten, Barnaby J.; Noreika, John

    2016-01-01

    Traditional downstream guidance and bypass facilities for anadromous fishes (i.e., surface bypasses, surface guidance structures, and behavioral barriers) have frequently been ineffective for anguillid eels. Because eels typically spend the majority of their time near the bottom in the vicinity of intake structures, deep bypass structures with entrances near the bottom hold promise for increased effectiveness, thereby aiding in the recovery of this important species. A new design of a deep bypass system that uses airlift technology (the Conte Airlift Bypass) to induce flow in a bypass pipe was tested in a simulated intake entrance environment under controlled laboratory conditions. Water velocities of 0.9–1.5 m s−1 could be generated at the bypass entrance (opening with 0.073 m2 area), with corresponding flows through the bypass pipe of 0.07–0.11 m3 s−1. Gas saturation and hydrostatic pressure within the bypass pipe did not vary appreciably from a control (no air) condition under tested airflows. Migratory silver-phase American eels (Anguilla rostrata) tested during dark conditions readily located, entered, and passed through the bypass; initial avoidance rates (eels approaching but not entering the bypass entrance) were lower at higher entrance velocities. Eels that investigated the bypass pipe entrance tended to enter headfirst, but those that then exited the pipe upstream did so more frequently at lower entrance velocities. Eels appeared to swim against the flow while being transported downstream through the pipe; median transit times through the bypass for each test velocity ranged from 5.8 to 12.2 s, with transit time decreasing with increasing entrance velocity. Eels did not show strong avoidance of the vertical section of the pipe which contained injected air. No mortality or injury of bypassed eels was observed, and individual eels repeatedly passed through the bypass at rates of up to 40 passes per hour, suggesting that individuals do not

  3. Survival and progression rates of anadromous brown trout kelts Salmo trutta during downstream migration in freshwater and at sea

    DEFF Research Database (Denmark)

    Aarestrup, Kim; Baktoft, Henrik; Thorstad, EB

    2015-01-01

    The marine migration of post-spawning anadromous fish remains poorly understood. The present study examined survival and progression rates of anadromous brown trout Salmo trutta L. after spawning (kelts) during downriver, fjord, and sea migration. Kelts (n = 49) were captured in the Danish River...... completing the reach within 4 d, suggesting that the kelts spent limited time foraging after returning to the fjord. The total survival during the entire marine migration, including the fjord, was a minimum of 29%. Our study provides data that are important for management of anadromous brown trout...

  4. "Investigations of salmon and steelhead trout downstream migrations in Caspar Creek and Little River, Mendocino County, March-July, 1993"

    Science.gov (United States)

    Albert Rodriguez; Weldon Jones

    1993-01-01

    Abstract - This annual study has been conducted, since 1987, on two coastal streams, in order to observe the different trend patterns of juvenile out migrations for coho salmon and steelhead-trout, figure 1. Analysis of the 1993 trapping season indicates, at Little River, a decrease of steelhead-trout yearlings but an increase in coho ""y+"". Coho...

  5. SOLUTION FOR ICHTHYOFAUNA MIGRATION UPSTREAM- DOWNSTREAM OF THE TWO SPILLWAYS LOCATED NEAR MANASTUR DAM ON THE SOMESUL MIC RIVER IN THE CLUJ NAPOCA CITY (ROMÂNIA

    Directory of Open Access Journals (Sweden)

    Razvan VOICU

    2015-06-01

    Full Text Available Longitudinal connectivity represent the way in which organisms move the energy and material exchanges located throughout the water. Fragmentation the longitudinal connectivity of watercourses caused by dams or other hydrotechnical constructions represent a major impact on sediment transport, hydrological regime, downstream moving and biota migration. The hydromorphological elements (river continuity, as well as chemical, biological, physicochemical elements characterize the ecological status of rivers.Migratory fish species: nase (Chondrostoma nasus - protected by Bern Convention - Appendix III and barbel (Barbus barbus - rare species, protected Habitats Directive (Annex V, annex 4A of Low nr.462 and Red List of RBDD are blocked but the Hydrotechnical constructions (discharge sills, dams etc located across the watercourse Somes Mic River. One of the important think of this system is the gravitational fall of water. This solution will lead to the restoration of the longitudinal connection of the Someşul Mic River in the Manastur neighborhood. România is part of the European Union and it has the obligation to implement the provisions of the Water Framework Directive 2000/60/EC, transposed into Romanian legislation by the Water Law 107/1996 as supplemented and amended (Act 310/2004. This engineering solution for fish fauna migration upstream – downstream of the spillways supports the Water Framework Directive 2000/60/EC, transposed into Romanian legislation by the Water Law 107/1996 as supplemented and amended (Act 310/2004.

  6. Pontic shad (Alosa immaculata migrating upstream the Danube river and larval drift downstream to the Black Sea in 2016

    Directory of Open Access Journals (Sweden)

    NĂSTASE Aurel

    2018-05-01

    Full Text Available The genus Alosa is present only in the northern hemisphere of the earth with four species living in North America and others five in Europe, from which Pontic shad (Alosa immaculata is subject of present study. Migration of shad depends of the environmental drivers such as increasing spring water temperature and river flooding. In 2016, both factors favoured an earlier start of shad migration in February with peak of spawning run in April, and ended in mid of May. Afterwards the size of catches and market demands no longer motivated fishermen to fish and sell Pontic shads. The 2016 catch of 386 t fitted in the multiannual 10-11 years cyclical catches. Reproduction success was estimated by Larval Abundance Index (LAI standardized as Catch per Unit Effort (CPUE by number of larvae per 100 m3 filtered water volume. Relative abundance of drifting larvae in 2016 compared with other 6 previously years showed that average LAI varied widely (2-1,252 larvae per 100 m3 with an average of 84 larvae/100 m3 which was ranked in regular reproductive success.

  7. Isolation of Fully Human Antagonistic RON Antibodies Showing Efficient Block of Downstream Signaling and Cell Migration1

    Science.gov (United States)

    Gunes, Zeynep; Zucconi, Adriana; Cioce, Mario; Meola, Annalisa; Pezzanera, Monica; Acali, Stefano; Zampaglione, Immacolata; De Pratti, Valeria; Bova, Luca; Talamo, Fabio; Demartis, Anna; Monaci, Paolo; La Monica, Nicola; Ciliberto, Gennaro; Vitelli, Alessandra

    2011-01-01

    RON belongs to the c-MET family of receptor tyrosine kinases. As its well-known family member MET, RON and its ligand macrophage-stimulating protein have been implicated in the progression and metastasis of tumors and have been shown to be overexpressed in cancer. We generated and tested a large number of human monoclonal antibodies (mAbs) against human RON. Our screening yielded three high-affinity antibodies that efficiently block ligand-dependent intracellular AKT and MAPK signaling. This effect correlates with the strong reduction of ligand-activated migration of T47D breast cancer cell line. By cross-competition experiments, we showed that the antagonistic antibodies fall into three distinct epitope regions of the RON extracellular Sema domain. Notably, no inhibition of tumor growth was observed in different epithelial tumor xenografts in nude mice with any of the antibodies. These results suggest that distinct properties beside ligand antagonism are required for anti-RON mAbs to exert antitumor effects in vivo. PMID:21286376

  8. Automated and Assistive Tools for Accelerated Code migration of Scientific Computing on to Heterogeneous MultiCore Systems

    Science.gov (United States)

    2017-04-13

    AFRL-AFOSR-UK-TR-2017-0029 Automated and Assistive Tools for Accelerated Code migration of Scientific Computing on to Heterogeneous MultiCore Systems ...2012, “ Automated and Assistive Tools for Accelerated Code migration of Scientific Computing on to Heterogeneous MultiCore Systems .” 2. The objective...2012 - 01/25/2015 4. TITLE AND SUBTITLE Automated and Assistive Tools for Accelerated Code migration of Scientific Computing on to Heterogeneous

  9. [Overexpression of N-myc downstream regulated gene 2 (NDRG2) inhibits proliferation, migration and promotes apoptosis in SW480 rectal cancer cells].

    Science.gov (United States)

    Li, Zhiqiang; Sun, Yang; Wan, Hongxing; Chai, Fang

    2017-01-01

    Objective To investigate the role of N-myc downstream regulated gene 2 (NDRG2) gene in the proliferation, migration and apoptosis of rectal cancer cells. Methods Human rectal cancer SW480 cells were cultured and transfected with pCDNA3.1-NDRG2 and empty vector (SW480-Ve). SW480 cells were set as a control group. Cell proliferation was detected in SW480 cells, SW480-Ve cells and SW480-NDRG2 cells by MTT assay; cell migration distance in the three groups at 24, 48, 72 hours was tested by wound healing assay; apoptosis rate was determined in the three groups at 48 hours by flow cytometry; the expressions of Bax, caspase-3, Bcl-2 proteins in the three groups were examined by Western blotting. Results After the cells were cultured for 7 days, cell survival rate in SW480-NDRG2 group was significantly lower than that in SW480 cells and SW480-Ve cells; the cell survival rate decreased gradually with the prolongation of the culture time; and it had no significant difference between SW480-Ve group and SW480 group. Cell migration distance in SW480-NDRG2 group was significantly lower than that in SW480-Ve cells and SW480 cells, and it had also no significant difference between SW480-Ve cells and SW480 cells. The apoptosis rate in SW480-NDRG2 group was significantly higher than that in SW480 group and SW480-Ve group, and SW480 cells and SW480-Ve cells had no significant difference in the rate. The expressions of Bax and caspase-3 proteins in SW480-NDRG2 group were significantly higher than those in SW480 cells and SW480-Ve cells; Bcl-2 protein expression was significantly lower in SW480-NDRG2 group than in SW480 cells and SW480-Ve cells; and the expressions of Bax, caspase-3 and Bcl-2 proteins were not significantly different between SW480 cells and SW480-Ve cells. Conclusion Overexpression of NDRG2 can inhibit the proliferation, reduce cell migration, and promote cell apoptosis by regulating the expressions of Bcl-2, Bax and caspase-3 proteins in SW480 cells.

  10. Focal adhesion kinase, a downstream mediator of Raf-1 signaling, suppresses cellular adhesion, migration, and neuroendocrine markers in BON carcinoid cells.

    Science.gov (United States)

    Ning, Li; Chen, Herbert; Kunnimalaiyaan, Muthusamy

    2010-05-01

    We have recently reported that activation of the Raf-1/mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK) kinase 1/2 (MEK1/2)/ERK1/2 signaling cascade in gastrointestinal carcinoid cell line (BON) alters cellular morphology and neuroendocrine phenotype. The mechanisms by which Raf-1 mediates these changes in carcinoid cells are unclear. Here, we report that activation of the Raf-1 signaling cascade in BON cells induced the expression of focal adhesion kinase (FAK) protein, suppressed the production of neuroendocrine markers, and resulted in significant decreases in cellular adhesion and migration. Importantly, inactivation of MEK1/2 by 1,4-diamino-2,3-dicyano-1,4-bis[2-aminophenylthio]butadiene or abolition of FAK induction in Raf-1-activated BON cells by targeted siRNA led to reversal of the Raf-1-mediated reduction in neuroendocrine markers and cellular adhesion and migration. Phosphorylation site-specific antibodies detected the phosphorylated FAK(Tyr407), but not FAK(Tyr397), in these Raf-1-activated cells, indicating that FAK(Tyr407) may be associated with changes in the neuroendocrine phenotype. Overexpression of constitutively active FAK plasmids (wild-type FAK or FAK(Tyr397) mutant) into BON cells reduced neuroendocrine markers, whereas the FAK(Tyr407) mutant plasmid did not show any decrease in the levels of neuroendocrine markers, indicating that phosphorylation of FAK at the Tyr(407) residue may be important for these effects. Our results showed for the first time that FAK is an essential downstream effector of the Raf-1/MEK1/2/ERK1/2 signaling cascade and negatively regulated the neuroendocrine and metastatic phenotype in BON cells. (c)2010 AACR.

  11. Void-assisted grain boundary migration in ion-irradiated austenitic stainless steels

    International Nuclear Information System (INIS)

    Vaidya, W.V.

    1983-01-01

    A number of austenitic stainless steels (15 wt% Cr-15 wt% Ni) were irradiated in the solution-annealed condition with 46 MeV Nisup(6+)-ions to a dose-level of 64 dpa at 848 K. Though the microstructure was initially well-equilibrated, under irradiation a general interface migration was observed, the most pronounced being at grain boundaries followed by that at incoherent and even at coherent twins. Changes at the migrating interfaces, features of the migration and variations in the near grain boundary voidage are described. After considering various possibilities which might have caused the migration, it is shown that the observed migration was void-assisted. This has led to the conclusion that voids by nature do not constitute an obstacle for the migrating interface but on the contrary, they offer driving force. Therefore, migration becomes feasible even in the solution-annealed specimens in which inherently there should be a least tendency for such a migration. (orig.)

  12. Void-assisted grain boundary migration in ion-irradiated austenitic stainless steels

    International Nuclear Information System (INIS)

    Vaidya, W.V.

    1983-01-01

    A number of austenitic stainless steels (15 wt% Cr-15 wt% Ni) were irradiated in the solution-annealed condition with 46 MeV Ni 6+ -ions to a dose-level of 64 dpa at 848 K. Though the microstructure was initially well-equilibrated, under irradiation a general interface migration was observed, the most pronounced being at grain boundaries followed by that at incoherent and even at coherent twins. Changes at the migrating interfaces, features of the migration and variations in the near grain boundary voidage are described. After considering various possibilities which might have caused the migration, it is shown that the observed migration was void-assisted. This has led to the conclusion that voids by nature do not constitute an obstacle for the migrating interface but on the contrary, they offer driving force. Therefore, migration becomes feasible even in the solution-annealed specimens in which inherently there should be a least tendency for such a migration. (orig.)

  13. Considerations for restoring temperate forests of tomorrow: Forest restoration, assisted migration, and bioengineering

    Science.gov (United States)

    Kas Dumroese; Mary I. Williams; John A. Stanturf; Brad St. Clair

    2015-01-01

    Tomorrow’s forests face extreme pressures from contemporary climate change, invasive pests, and anthropogenic demands for other land uses. These pressures, collectively, demand land managers to reassess current and potential forest management practices. We discuss three considerations, functional restoration, assisted migration, and bioengineering, which are currently...

  14. Different geographies and experiences of 'assisted' types of migration. A gendered critique on the distinction between trafficking and smuggling.

    NARCIS (Netherlands)

    Liempt, I.C. van

    2011-01-01

    This article presents three stories of female migrants who were assisted in their migration process from the Horn of Africa, Iraq and the former Soviet Union to the Netherlands. The stories are contextualized within the results of a wider research project on assisted migration involving 56

  15. Fps/Fes protein-tyrosine kinase regulates mast cell adhesion and migration downstream of Kit and beta1 integrin receptors.

    Science.gov (United States)

    Smith, Julie A; Samayawardhena, Lionel A; Craig, Andrew W B

    2010-03-01

    Activation of Kit receptor protein-tyrosine kinase (PTK) by its ligand Stem Cell Factor (SCF) is required for the development of mast cells, and for the regulation of mast cell proliferation, migration and modulation of inflammatory mediator release. Recent studies have implicated the non-receptor PTK Fps/Fes (hereafter referred to as Fes) in signaling downstream of oncogenic Kit, however, the potential role of Fes in regulating Kit signaling is not well defined. In this study, we show that SCF induces transient tyrosine phosphorylation of wild-type Fes as well as kinase-dead Fes in bone marrow-derived mast cells (BMMCs). The latter finding implicates an upstream kinase acting on Fes, which we identified as Fyn PTK. SCF treatment of BMMCs promoted recruitment of Fes to Kit, potentially via direct interaction of the Fes SH2 domain with phosphorylated Kit. While Fes was not required for SCF-induced signaling to Akt and Erk kinases, Fes-deficient (fes-/-) BMMCs displayed a defect in sustained p38 kinase activation, compared to control cells. SCF-treated Fes-deficient BMMCs also displayed elevated beta1 integrin-mediated cell adhesion and spreading on fibronectin, compared to control cells, and a reduction in cell polarization at later times of SCF treatment. Restoring Fes expression in fes-/- BMMCs by retroviral transduction was sufficient to rescue cell spreading and polarization defects. Interestingly, SCF-induced chemotaxis of BMMCs was also defective in Fes-deficient BMMCs, and restored in Fes-rescue BMMCs. Overall, these results implicate Fes in regulating cross-talk between Kit and beta1 integrins to promote cytoskeletal reorganization and motility of mast cells.

  16. Bats on a Budget: Torpor-Assisted Migration Saves Time and Energy

    Science.gov (United States)

    McGuire, Liam P.; Jonasson, Kristin A.; Guglielmo, Christopher G.

    2014-01-01

    Bats and birds must balance time and energy budgets during migration. Migrating bats face similar physiological challenges to birds, but nocturnality creates special challenges for bats, such as a conflict between travelling and refueling, which many birds avoid by feeding in daylight and flying at night. As endothermic animals, bats and birds alike must expend substantial amounts of energy to maintain high body temperatures. For migratory birds refueling at stopovers, remaining euthermic during inactive periods reduces the net refuelling rate, thereby prolonging stopover duration and delaying subsequent movement. We hypothesized that bats could mitigate similar ambient-temperature dependent costs by using a torpor-assisted migration strategy. We studied silver-haired bats Lasionycteris noctivagans during autumn migration using a combination of respirometry and temperature-sensitive radiotelemetry to estimate energy costs incurred under ambient temperature conditions, and the energy that bats saved by using torpor during daytime roosting periods. All bats, regardless of sex, age, or body condition used torpor at stopover and saved up to 91% of the energy they would have expended to remain euthermic. Furthermore, bats modulated use of torpor depending on ambient temperature. By adjusting the time spent torpid, bats achieved a rate of energy expenditure independent of the ambient temperature encountered at stopover. By lowering body temperature during inactive periods, fuel stores are spared, reducing the need for refuelling. Optimal migration models consider trade-offs between time and energy. Heterothermy provides a physiological strategy that allows bats to conserve energy without paying a time penalty as they migrate. Although uncommon, some avian lineages are known to use heterothermy, and current theoretical models of migration may not be appropriate for these groups. We propose that thermoregulatory strategies should be an important consideration of future

  17. Leader cells regulate collective cell migration via Rac activation in the downstream signaling of integrin β1 and PI3K.

    Science.gov (United States)

    Yamaguchi, Naoya; Mizutani, Takeomi; Kawabata, Kazushige; Haga, Hisashi

    2015-01-07

    Collective cell migration plays a crucial role in several biological processes, such as embryonic development, wound healing, and cancer metastasis. Here, we focused on collectively migrating Madin-Darby Canine Kidney (MDCK) epithelial cells that follow a leader cell on a collagen gel to clarify the mechanism of collective cell migration. First, we removed a leader cell from the migrating collective with a micromanipulator. This then caused disruption of the cohesive migration of cells that followed in movement, called "follower" cells, which showed the importance of leader cells. Next, we observed localization of active Rac, integrin β1, and PI3K. These molecules were clearly localized in the leading edge of leader cells, but not in follower cells. Live cell imaging using active Rac and active PI3K indicators was performed to elucidate the relationship between Rac, integrin β1, and PI3K. Finally, we demonstrated that the inhibition of these molecules resulted in the disruption of collective migration. Our findings not only demonstrated the significance of a leader cell in collective cell migration, but also showed that Rac, integrin β1, and PI3K are upregulated in leader cells and drive collective cell migration.

  18. The good, the bad and the recovery in an assisted migration.

    Directory of Open Access Journals (Sweden)

    Bridget S Green

    2010-11-01

    Full Text Available Assisted migration or translocation of species to ameliorate effects of habitat loss or changing environment is currently under scrutiny as a conservation tool. A large scale experiment of assisted migration over hundreds of kilometres was tested on a morph from a commercial fishery of southern rock lobster Jasus edwardsii, to enhance depleted populations, improve the yield and sustainability of the fishery, and test resilience to a changing climate.Approximately 10,000 lower-valued, pale-coloured lobsters were moved from deep water to inshore sites (2 in Tasmania [TAS] and 2 in South Australia [SA] where the high-value, red morph occurs. In TAS this was a northwards movement of 1° latitude. Growth was measured only in TAS lobsters, and reproductive status was recorded in lobsters from all locations. Pale females (TAS grew 4 times faster than resident pale lobsters from the original site and twice as fast as red lobsters at their new location. Approximately 30% of translocated pale lobsters deferred reproduction for one year after release (SA and TAS, and grew around 1 mm yr(-1 less compared to translocated pale lobsters that did not defer reproduction. In spite of this stress response to translocation, females that deferred reproduction still grew 2-6 mm yr(-1 more than lobsters at the source site. Lobsters have isometric growth whereby volume increases as a cube of length. Consequently despite the one-year hiatus in reproduction, increased growth increases fecundity of translocated lobsters, as the increase in size provided a larger volume for producing and incubating eggs in future years.Assisted migration improved egg production and growth, despite a temporary stress response, and offers a tool to improve the production, sustainability and resilience of the fishery.

  19. Synapsin III Acts Downstream of Semaphorin 3A/CDK5 Signaling to Regulate Radial Migration and Orientation of Pyramidal Neurons In Vivo

    Directory of Open Access Journals (Sweden)

    Laura E. Perlini

    2015-04-01

    Full Text Available Synapsin III (SynIII is a phosphoprotein that is highly expressed at early stages of neuronal development. Whereas in vitro evidence suggests a role for SynIII in neuronal differentiation, in vivo evidence is lacking. Here, we demonstrate that in vivo downregulation of SynIII expression affects neuronal migration and orientation. By contrast, SynIII overexpression affects neuronal migration, but not orientation. We identify a cyclin-dependent kinase-5 (CDK5 phosphorylation site on SynIII and use phosphomutant rescue experiments to demonstrate its role in SynIII function. Finally, we show that SynIII phosphorylation at the CDK5 site is induced by activation of the semaphorin-3A (Sema3A pathway, which is implicated in migration and orientation of cortical pyramidal neurons (PNs and is known to activate CDK5. Thus, fine-tuning of SynIII expression and phosphorylation by CDK5 activation through Sema3A activity is essential for proper neuronal migration and orientation.

  20. Evidence for an autumn downstream migration of Atlantic salmon Salmo salar (Linnaeus) and brown trout Salmo trutta (Linnaeus) parr to the Baltic Sea

    Science.gov (United States)

    Taal, Imre; Kesler, Martin; Saks, Lauri; Rohtla, Mehis; Verliin, Aare; Svirgsden, Roland; Jürgens, Kristiina; Vetemaa, Markus; Saat, Toomas

    2014-06-01

    In the eastern Baltic rivers, anadromous salmonid parr are known to smoltify and migrate to the sea from March until June, depending on latitude, climate and hydrological conditions. In this study, we present the first records of autumn descent of brown trout Salmo trutta and Atlantic salmon Salmo salar from the Baltic Sea Basin. Otolith microchemistry analyses revealed that these individuals hatched in freshwater and had migrated to the brackish water shortly prior to capture. The fish were collected in 2006, 2008, 2009 and 2013 from Eru Bay (surface salinity 4.5-6.5 ‰), Gulf of Finland. This relatively wide temporal range of observations indicates that the autumn descent of anadromous salmonids is not a random event. These results imply that autumn descent needs more consideration in the context of the effective stock management, assessment and restoration of Baltic salmonid populations and their habitats.

  1. Investigating perioperative heart migration during robot-assisted coronary artery bypass grafting interventions.

    Science.gov (United States)

    Linte, Cristian A; Cho, Daniel S; Wedlake, Chris; Moore, John; Chen, Elvis; Bainbridge, Daniel; Patel, Rajni; Peters, Terry; Kiaii, Bob B

    2011-09-01

    : For robot-assisted coronary artery bypass graft interventions, surgeons typically use a preoperative thoracic computed tomography scan of the patient to plan the procedure. However, the cardiac anatomy is prone to changes induced perioperatively in the effort to access the heart and surgical targets, which, in turn, may invalidate the initial plan. This article presents a method to estimate the perioperative heart migration, information which can be further exploited to refine the preoperative surgical plan. : Tracked transesophageal ultrasound images of four patients' hearts were acquired at each stage in the procedure: before lung deflation, after lung deflation, and after both lung deflation and CO2 thoracic insufflation. Anatomic features of interest-the mitral and aortic valves-were identified from each dataset, and their movement between the different procedure stages was recorded and used to estimate the global heart displacement. Moreover, the local morphology of the features of interest was investigated to provide insight on the extent of the deformation the heart has undergone during the workflow. : The study suggested that the heart does undergo substantial displacement-on the order of 10 to 15 mm in each direction (axial, coronal, and sagittal) after lung deflation and CO2 thoracic insufflation. However, no significant differences (P > 0.1) were observed in the morphologic characteristics of the features of interest across the multiple workflow stages, suggesting that local deformations occur at a much smaller scale compared with the global migration. : The quantification of the perioperatively induced changes is critical to track the displacement of the heart and surgical targets. The recorded migration patterns should not be ignored but rather be used to update the surgical plan to better suit the intraoperative environment.

  2. Conflicting modes of reasoning in the Assisted Migration debate: a concept mapping analysis

    Science.gov (United States)

    Klenk, N. L.; Larson, B.

    2011-12-01

    A growing body of literature in biodiversity conservation and forestry has developed around the risks and benefits of the Assisted Migration (AM) of species, including recommendations for planning and management. However, despite years of academic debate, general consensus has yet to be reached between the proponents and the opponents of AM as a policy option. We hypothesize that the continued impasse arises out of fundamentally conflicting value judgments. Using a concept mapping technique, we analyzed reasons for and against AM, including the use of scientific evidence and the nature of the values and ethical norms that shape the modes of reasoning in the debate. Our results indicate the presence of a diversity of ethical arguments in addition to the standard precautionary argument and pragmatic reasoning. We further discovered that different kinds of scientific arguments are used by proponents versus opponents of AM: the former rely mostly on detailed biological and ecological facts about species most-at-risk under climate change, while the latter focus on broader ecological theories. Our analysis suggests little dispute over the scientific foundations of the debate. Instead, we suggest that the main barrier to consensus is the advocacy of fundamental values, which are a matter of personal choice, and thus not likely to be changed. One way out of this impasse is a pragmatic mode of reasoning, which eschews the debate on fundamental values and evaluates the means and ends of AM in a case-by-case approach.

  3. Classical Ecological Restoration and its Current Challenges: Assisted Migration as an Adaptation Strategy to Climate Change

    Directory of Open Access Journals (Sweden)

    Pilar A. Gómez-Ruiz

    2017-06-01

    Full Text Available Ecological restoration is a very active area in ecology and of great importance for ecosystems management. Despite of being a relatively young discipline, the classical concepts of restoration seem, at present, impractical considering the great challenges generated by modification and destruction of ecosystems. This is due to anthropic activities (deforestation, change of land use, pollution and global climate change. In the classic definition of restoration, the objective is to recover the degraded ecosystem to the same conditions of a historical reference state. However, nowadays the ecosystems return to a state prior to the disturbances seems unviable, because the thresholds of resilience have already been overcome. Additionally, climate change is causing environmental changes at an unprecedented rate. For this reason, ecological restoration needs to unite efforts of diverse actors to recover ecosystems that can be sustainable and functional in the future, where the species could be able to tolerate the environmental conditions that will exist in the long term. Assisted migration has been proposed as a conservation strategy; it is defined as the translocation of species to new locations outside their known range of distribution. In the current context of loss of diversity and ecosystems, this strategy could be fundamental for the formation of new communities that can later become novel ecosystems where species that are fundamental to the dynamics of ecosystems can persist and, at the same time, recover function, structure and resilience.

  4. Douglas-fir plantations in Europe: a retrospective test of assisted migration to address climate change.

    Science.gov (United States)

    Isaac-Renton, Miriam G; Roberts, David R; Hamann, Andreas; Spiecker, Heinrich

    2014-08-01

    We evaluate genetic test plantations of North American Douglas-fir provenances in Europe to quantify how tree populations respond when subjected to climate regime shifts, and we examined whether bioclimate envelope models developed for North America to guide assisted migration under climate change can retrospectively predict the success of these provenance transfers to Europe. The meta-analysis is based on long-term growth data of 2800 provenances transferred to 120 European test sites. The model was generally well suited to predict the best performing provenances along north-south gradients in Western Europe, but failed to predict superior performance of coastal North American populations under continental climate conditions in Eastern Europe. However, model projections appear appropriate when considering additional information regarding adaptation of Douglas-fir provenances to withstand frost and drought, even though the model partially fails in a validation against growth traits alone. We conclude by applying the partially validated model to climate change scenarios for Europe, demonstrating that climate trends observed over the last three decades warrant changes to current use of Douglas-fir provenances in plantation forestry throughout Western and Central Europe. © 2014 John Wiley & Sons Ltd.

  5. Patterning of Endothelial Cells and Mesenchymal Stem Cells by Laser-Assisted Bioprinting to Study Cell Migration

    Directory of Open Access Journals (Sweden)

    Jean-Michel Bourget

    2016-01-01

    Full Text Available Tissue engineering of large organs is currently limited by the lack of potent vascularization in vitro. Tissue-engineered bone grafts can be prevascularized in vitro using endothelial cells (ECs. The microvascular network architecture could be controlled by printing ECs following a specific pattern. Using laser-assisted bioprinting, we investigated the effect of distance between printed cell islets and the influence of coprinted mesenchymal cells on migration. When printed alone, ECs spread out evenly on the collagen hydrogel, regardless of the distance between cell islets. However, when printed in coculture with mesenchymal cells by laser-assisted bioprinting, they remained in the printed area. Therefore, the presence of mesenchymal cell is mandatory in order to create a pattern that will be conserved over time. This work describes an interesting approach to study cell migration that could be reproduced to study the effect of trophic factors.

  6. Patterning of Endothelial Cells and Mesenchymal Stem Cells by Laser-Assisted Bioprinting to Study Cell Migration.

    Science.gov (United States)

    Bourget, Jean-Michel; Kérourédan, Olivia; Medina, Manuela; Rémy, Murielle; Thébaud, Noélie Brunehilde; Bareille, Reine; Chassande, Olivier; Amédée, Joëlle; Catros, Sylvain; Devillard, Raphaël

    2016-01-01

    Tissue engineering of large organs is currently limited by the lack of potent vascularization in vitro . Tissue-engineered bone grafts can be prevascularized in vitro using endothelial cells (ECs). The microvascular network architecture could be controlled by printing ECs following a specific pattern. Using laser-assisted bioprinting, we investigated the effect of distance between printed cell islets and the influence of coprinted mesenchymal cells on migration. When printed alone, ECs spread out evenly on the collagen hydrogel, regardless of the distance between cell islets. However, when printed in coculture with mesenchymal cells by laser-assisted bioprinting, they remained in the printed area. Therefore, the presence of mesenchymal cell is mandatory in order to create a pattern that will be conserved over time. This work describes an interesting approach to study cell migration that could be reproduced to study the effect of trophic factors.

  7. Species distribution models may misdirect assisted migration: insights from the introduction of Douglas-fir to Europe.

    Science.gov (United States)

    Boiffin, Juliette; Badeau, Vincent; Bréda, Nathalie

    2017-03-01

    Species distribution models (SDMs), which statistically relate species occurrence to climatic variables, are widely used to identify areas suitable for species growth under future climates and to plan for assisted migration. When SDMs are projected across times or spaces, it is assumed that species climatic requirements remain constant. However, empirical evidence supporting this assumption is rare, and SDM predictions could be biased. Historical human-aided movements of tree species can shed light on the reliability of SDM predictions in planning for assisted migration. We used Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), a North American conifer introduced into Europe during the mid-19th century, as a case-study to test niche conservatism. We combined transcontinental data sets of Douglas-fir occurrence and climatic predictors to compare the realized niches between native and introduced ranges. We calibrated a SDM in the native range and compared areas predicted to be climatically suitable with observed presences. The realized niches in the native and introduced ranges showed very limited overlap. The SDM calibrated in North America had very high predictive power in the native range, but failed to predict climatic suitability in Europe where Douglas-fir grows in climates that have no analogue in the native range. We review the ecological mechanisms and silvicultural practices that can trigger such shifts in realized niches. Retrospective analysis of tree species introduction revealed that the assumption of niche conservatism is erroneous. As a result, distributions predicted by SDM are importantly biased. There is a high risk that assisted migration programs may be misdirected and target inadequate species or introduction zones. © 2016 by the Ecological Society of America.

  8. Assisted migration: What it means to nursery managers and tree planters

    Science.gov (United States)

    Mary I. Williams; R. Kasten Dumroese

    2014-01-01

    Projections indicate that natural plant adaptation and migration may not keep pace with climate changes. This mismatch in rates will pose significant challenges for practitioners that select, grow, and outplant native tree species. Populations of native tree species planted today must be able to meet the climatic challenges they will face during this century. One...

  9. Behaviour and passage of European silver eels (Anguilla anguilla at a small hydropower plant during their downstream migration Comportement et passage de l’anguille argentée (Anguilla anguilla au niveau d’une petite centrale hydroélectrique lors de sa migration de dévalaison

    Directory of Open Access Journals (Sweden)

    De-Oliveira E.

    2010-09-01

    Full Text Available Between 2004 and 2007, 116 downstream migrant silver eels (Anguilla anguilla were monitored at a hydropower plant on the Gave de Pau river in South-West France using radio and PIT telemetry. The objectives of the study were: (i to determine the environmental conditions when eels arrived and passed the facility; (ii to determine the rate of eel escapement (passage other than via the turbines; (iii to describe the behaviour of eels faced with the intake structure and the permeability of the intake trashracks for the different sizes of eel; and (iv to determine whether surface bypasses originally designed for salmon could be effective for eels. Five types of behaviour of silver eels in the forebay and at the plant intakes were identified. The study showed the key factor influencing both eel behaviour and the route taken through the plant was variation in river discharge. Escapement rate was related to eel length and the spill flow to river flow ratio, which could be described by a logistic regression model. The surface bypasses originally designed for salmon were found to aid downstream eel migration significantly. At velocities < 0.40 m·s−1, no eels, even the largest, for which the racks are a physical barrier, were found impinged on the trashracks. De 2004 à 2007, une étude sur la migration de dévalaison de l’anguille argentée européenne (Anguilla anguilla a été menée sur la centrale hydroélectrique de Baigts sur le Gave de Pau dans le Sud-Ouest de la France. Cette étude, au cours de laquelle 116 individus ont été suivis par télémétrie PIT et radio, avait pour objectifs : (i de déterminer les conditions de milieu propices à l’arrivée sur site et au franchissement de l’aménagement; (ii de déterminer les taux d’échappement (passages par des voies autres que les turbines; (iii d’analyser le comportement des anguilles devant les ouvrages et la perméabilité des grilles de la prise d’eau en fonction de la taille

  10. Permian-Triassic maturation and multistage migration of hydrocarbons in the Assistência Formation (Irati Subgroup, Paraná Basin, Brazil: implications for the exploration model

    Directory of Open Access Journals (Sweden)

    António Mateus

    Full Text Available New lines of geological evidence strongly suggest that the main period of hydrocarbon maturation within Assistência Formation should be Permian-Triassic, stimulated by a high geothermal gradient that also sustained various manifestations of hydrothermal activity. Three main stages of fluid/hydrocarbon migration can also be inferred on the basis of multiscale observations: confined flow in late Permian to Triassic times, depending on the local build-up of fluid pressures; heterogeneous flow in Lower Cretaceous, triggered by a rejuvenated temperature gradient assisted by the early developed permeability conditions; and a late flow possibly driven by local pressure gradients, after complete cooling of dolerite dykes/sills. The early maturation and multistage migration of hydrocarbons have significant consequences in the design of exploration models to be applied in Paraná Basin.

  11. India's Downstream Petroleum Sector

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    This study provides a holistic examination of pricing and investment dynamics in India's downstream petroleum sector. It analyses the current pricing practices, highlights the tremendous fiscal cost of current pricing and regulatory arrangements, and examines the sectoral investment dynamics. It also looks at potential paths towards market-based reform along which the Indian government may move, while at the same time protecting energy market access for India's large poor population.

  12. Ecophysiology and Growth of White Spruce Seedlings from Various Seed Sources along a Climatic Gradient Support the Need for Assisted Migration

    OpenAIRE

    Guillaume Otis Prud'homme; Mohammed S. Lamhamedi; Lahcen Benomar; André Rainville; Josianne DeBlois; Jean Bousquet; Jean Bousquet; Jean Beaulieu; Jean Beaulieu

    2018-01-01

    With climate change, favorable growing conditions for tree species are shifting northwards and to higher altitudes. Therefore, local populations are becoming less adapted to their environment. Assisted migration is one of the proposed adaptive measures to reduce the vulnerability of natural populations and maintain forest productivity. It consists of moving genetic material to a territory where future climate conditions correspond to those of its current location. Eight white spruce (Picea gl...

  13. Evaluating the Effects of Dam Construction on the Morphological Changes of Downstream Meandering Rivers (Case Study: Karkheh River

    Directory of Open Access Journals (Sweden)

    A. Liaghat

    2017-04-01

    Full Text Available The establishment of stability in rivers is dependent on a variety of factors, and yet the established stability can be interrupted at any moment or time. One factor that can strongly disrupt the stability of rivers is the construction of dams. For this study, the identification and evaluation of morphological changes occurring to the Karkheh River, before and after the construction of the Karkheh Dam, along with determining the degree of changes to the width and length of the downstream meanders of the river, have been performed with the assistance of satellite images and by applying the CCHE2D hydrodynamic model. Results show that under natural circumstances the width of the riverbed increases downstream parallel to the decrease in the slope angle of the river. The average width of the river was reduced from 273 meters to 60 meters after dam construction. This 78% decrease in river width has made available 21 hectares of land across the river bank per kilometer length of the river. In the studied area, the average thalweg migration of the river is approximately 340 meters, while the minimum and maximum of river migration measured 53 and 768 meters, respectively. Evaluations reveal that nearly 56% of the migrations pertain to the western side of the river, while over 59% of these migrations take place outside the previous riverbed. By average, each year, the lateral migration rate of the river is 34 meters in the studied area which signifies the relevant instability of the region.

  14. An overview of some concepts, potentials, issues, and realities of assisted migration for climate change adaptation in forests

    Science.gov (United States)

    Louis R. Iverson; Matthew P. Peters; Stephen Matthews; Anantha. Prasad

    2013-01-01

    The climate has always been changing, but the rapid rate of climate change, as projected by the IPCC (2007) will likely place unique stresses on plant communities. In addition, anthropogenic barriers (e.g., fragmented land use) present a significant modern constraint that will limit the ability of species migration in responses to a changing climate. As such, managers...

  15. Amide Bond Formation Assisted by Vicinal Alkylthio Migration in Enaminones: Metal- and CO-Free Synthesis of α,β-Unsaturated Amides.

    Science.gov (United States)

    Liu, Zhuqing; Huang, Fei; Wu, Ping; Wang, Quannan; Yu, Zhengkun

    2018-05-18

    Amide bond formation is one of the most important transformations in organic synthesis, drug development, and materials science. Efficient construction of amides has been among the most challenging tasks for organic chemists. Herein, we report a concise methodology for amide bond (-CONH-) formation assisted by vicinal group migration in alkylthio-functionalized enaminones (α-oxo ketene N, S-acetals) under mild conditions. Simple treatment of such enaminones with PhI(OAc) 2 at ambient temperature in air afforded diverse multiply functionalized α,β-unsaturated amides including β-cyclopropylated acrylamides, in which a wide array of functional groups such as aryl, (hetero)aryl, alkenyl, and alkyl can be conveniently introduced to a ketene moiety. The reaction mechanism was investigated by exploring the origins of the amide oxygen and carbon atoms as well as isolation and structural characterization of the reaction intermediates. The amide bond formation reactions could also be efficiently performed under solventless mechanical milling conditions.

  16. The mechanism of indium-assisted growth of (In)GaN nanorods: eliminating nanorod coalescence by indium-enhanced atomic migration.

    Science.gov (United States)

    Xu, Zhenzhu; Yu, Yuefeng; Han, Jinglei; Wen, Lei; Gao, Fangliang; Zhang, Shuguang; Li, Guoqiang

    2017-11-09

    Both well vertically aligned and uniformly separated (In)GaN nanorods (NRs) were successfully grown on Si(111) substrates by plasma-assisted molecular beam epitaxy. Effects of supplied indium (In) flux on the morphology of (In)GaN NRs were investigated systematically. The scanning electron microscopic analysis and transmission electron microscopic measurements revealed that the presence of In flux can help to inhibit NR coalescence and obtain well-separated (In)GaN NRs. By increasing the supplied In flux, the densities of (In)GaN NRs decreased and the axial growth rates increased. According to the energy dispersive X-ray spectrometry measurements and theoretical calculations, the increase of In content of the NRs enhanced Ga diffusion on the NR sidewalls, which resulted in an increased axial growth rate. A kinetic In-assisted growth model for the well-separated (In)GaN NRs is therefore proposed. The model explains that the presence of In flux not only reduces the density of (In)GaN NRs due to the increase in substrate surface migration of Ga adatoms at nucleation stage but also lead to a remarkable enhancement of axial growth rate at growth stage. Consequently, the NR coalescence was significantly suppressed. The results provide a demonstration of obtaining well-separated (In)GaN NRs and open up further possibility of developing (In)GaN NR-based optoelectronic devices.

  17. Ecophysiology and Growth of White Spruce Seedlings from Various Seed Sources along a Climatic Gradient Support the Need for Assisted Migration.

    Science.gov (United States)

    Otis Prud'homme, Guillaume; Lamhamedi, Mohammed S; Benomar, Lahcen; Rainville, André; DeBlois, Josianne; Bousquet, Jean; Beaulieu, Jean

    2017-01-01

    With climate change, favorable growing conditions for tree species are shifting northwards and to higher altitudes. Therefore, local populations are becoming less adapted to their environment. Assisted migration is one of the proposed adaptive measures to reduce the vulnerability of natural populations and maintain forest productivity. It consists of moving genetic material to a territory where future climate conditions correspond to those of its current location. Eight white spruce ( Picea glauca [Moench] Voss) seed sources representing as many seed orchards were planted in 2013 at three forest sites simulating a south-north climatic gradient of 1.7°C in Québec, Canada. The objectives were to (1) evaluate the morpho-physiological responses of the different seed sources and (2) determine the role of genetic adaptation and physiological plasticity on the observed variation in morpho-physiological traits. Various seedling characteristics were measured, notably height growth from nursery to the fourth year on plantation. Other traits such as biomass and carbon allocation, nutritional status, and various photosynthetic traits before bud break, were evaluated during the fourth growing season. No interaction between sites and seed sources was observed for any traits, suggesting similar plasticity between seed sources. There was no change in the rank of seed sources and sites between years for height growth. Moreover, a significant positive correlation was observed between the height from the nursery and that after 4 years in the plantation. Southern seed sources showed the best height growth, while optimum growth was observed at the central site. Juvenile height growth seems to be a good indicator of the juvenile carbon sequestration and could serve as a selection criterion for the best genetics sources for carbon sequestration. Vector analysis showed no nitrogen deficiency 4 years after planting. Neither seed sources nor planting sites had a significant effect on

  18. Ecophysiology and Growth of White Spruce Seedlings from Various Seed Sources along a Climatic Gradient Support the Need for Assisted Migration

    Directory of Open Access Journals (Sweden)

    Guillaume Otis Prud'homme

    2018-01-01

    Full Text Available With climate change, favorable growing conditions for tree species are shifting northwards and to higher altitudes. Therefore, local populations are becoming less adapted to their environment. Assisted migration is one of the proposed adaptive measures to reduce the vulnerability of natural populations and maintain forest productivity. It consists of moving genetic material to a territory where future climate conditions correspond to those of its current location. Eight white spruce (Picea glauca [Moench] Voss seed sources representing as many seed orchards were planted in 2013 at three forest sites simulating a south-north climatic gradient of 1.7°C in Québec, Canada. The objectives were to (1 evaluate the morpho-physiological responses of the different seed sources and (2 determine the role of genetic adaptation and physiological plasticity on the observed variation in morpho-physiological traits. Various seedling characteristics were measured, notably height growth from nursery to the fourth year on plantation. Other traits such as biomass and carbon allocation, nutritional status, and various photosynthetic traits before bud break, were evaluated during the fourth growing season. No interaction between sites and seed sources was observed for any traits, suggesting similar plasticity between seed sources. There was no change in the rank of seed sources and sites between years for height growth. Moreover, a significant positive correlation was observed between the height from the nursery and that after 4 years in the plantation. Southern seed sources showed the best height growth, while optimum growth was observed at the central site. Juvenile height growth seems to be a good indicator of the juvenile carbon sequestration and could serve as a selection criterion for the best genetics sources for carbon sequestration. Vector analysis showed no nitrogen deficiency 4 years after planting. Neither seed sources nor planting sites had a

  19. U.S. backs "well-being" programs for women. An interview with Julia Taft, Assistant Secretary of State for Population, Refugees and Migration.

    Science.gov (United States)

    Scherr, E F

    1998-09-01

    This interview with Julia Taft, Assistant Secretary of State for Population, Refugees and Migration concerns a wide range of well-being programs for women in the US. The ICPD Program of Action considers family planning and reproductive health in the broader contexts of women's empowerment, girls¿ and boys' education, child health, and social elements (among them economic and environmental elements), that affect the lives of girls and women. US programs and policies encompass the promotion of the whole range of well-being of women and girls, of which family planning and reproductive health are key elements. Congress has passed a law ensuring complete access to reproductive health care services by making it a crime to use force or to interfere with reproductive health providers or their patients. There was also a recent decision to require federal employees' health insurance plans to cover contraceptives. The US supports several international organizations working on population issues such as UNFPA, UNICEF, UNAIDS, WHO, and UNDP. The UN will continually have to evaluate its progress so that in 15 years human rights, civil rights, and proper health care will have been extended to the entire world.

  20. Continuous downstream processing of biopharmaceuticals.

    Science.gov (United States)

    Jungbauer, Alois

    2013-08-01

    Continuous manufacturing has been applied in many different industries but has been pursued reluctantly in biotechnology where the batchwise process is still the standard. A shift to continuous operation can improve productivity of a process and substantially reduce the footprint. Continuous operation also allows robust purification of labile biomolecules. A full set of unit operations is available to design continuous downstream processing of biopharmaceuticals. Chromatography, the central unit operation, is most advanced in respect to continuous operation. Here, the problem of 'batch' definition has been solved. This has also paved the way for implementation of continuous downstream processing from a regulatory viewpoint. Economic pressure, flexibility, and parametric release considerations will be the driving force to implement continuous manufacturing strategies in future. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Operational optimization in the downstream; Otimizacao operacional no downstream

    Energy Technology Data Exchange (ETDEWEB)

    Silberman, Luis; Cunha, Filipe Silveira Ramos da [Petroleo Ipiranga, Porto Alegre, RS (Brazil)

    2004-07-01

    On the present competitive down stream's market, there is a great necessity of optimization aiming to guarantee the best price and quality of our clients. Our goal is to attend these expectations while we guarantee an efficient operation. The greatest question is how far we are from the ideal model. This way, a lot of projects have been executed during the last years aiming the operational optimization of all our activities. We divide the projects in 4 areas: Logistic (new modals distribution), Transport (transport optimization - quality and more deliveries with less trucks), Client Support (Internet Ipiranga and Support Center), Distribution Terminals Productivity (automation and environment). This work intend to present our ideal, perfect and complete Downstream Operation model. We will talk about how close we are of this ideal model and we will present the projects that we had already developed and implanted on the automation of the terminals and the logistics area. (author)

  2. Downstream behavior of fission products

    International Nuclear Information System (INIS)

    Johnson, I.; Farahat, M.K.; Settle, J.L.; Johnson, C.E.; Ritzman, R.

    1986-01-01

    The downstream behavior of fission products has been investigated by injecting mixtures of CsOH, CsI, and Te into a flowing steam/hydrogen stream and determining the physical and chemical changes that took place as the gaseous mixture flowed down a reaction duct on which a temperature gradient (1000 0 to 200 0 C) had been imposed. Deposition on the wall of the duct occurred by vapor condensation in the higher temperature regions and by aerosol deposition in the remainder of the duct. Reactions in the gas stream between CsOH and CsI and between CsOH and Te had an effect on the vapor condensation. The aerosol was characterized by the use of impingement tabs placed in the gas stream

  3. A downstream voyage with mercury

    Science.gov (United States)

    Heinz, Gary

    2016-01-01

    Retrospective essay for the Bulletin of Environmental Contamination and Toxicology.As I look back on my paper, “Effects of Low Dietary Levels of Methyl Mercury on Mallard Reproduction,” published in 1974 in the Bulletin of Environmental Contamination and Toxicology, a thought sticks in my mind. I realize just how much my mercury research was not unlike a leaf in a stream, carried this way and that, sometimes stalled in an eddy, restarted, and carried downstream at a pace and path that was not completely under my control. I was hired in 1969 by the Patuxent Wildlife Research Center to study the effects of environmental pollutants on the behavior of wildlife. A colleague was conducting a study on the reproductive effects of methylmercury on mallards (Anas platyrhynchos), and he offered to give me some of the ducklings. I conducted a pilot study, testing how readily ducklings approached a tape-recorded maternal call. Sample sizes were small, but the results suggested that ducklings from mercury-treated parents behaved differently than controls. That’s how I got into mercury research—pretty much by chance.

  4. Rare earth industries: Downstream business

    International Nuclear Information System (INIS)

    2011-01-01

    The value chain of the rare earths business involves mining, extraction, processing, refining and the manufacture of an extensive range of downstream products which find wide applications in such industries including aerospace, consumer electronics, medical, military, automotive, renewable wind and solar energy and telecommunications. In fact the entire gamut of the high-tech industries depends on a sustainable supply of rare earths elements. The explosive demand in mobile phones is an excellent illustration of the massive potential that the rare earths business offers. In a matter of less than 20 years, the number of cell phones worldwide has reached a staggering 5 billion. Soon, going by the report of their growth in sales, the world demand for cell phones may even exceed the global population. Admittedly, the rare earths business does pose certain risks. Top among the risks are the health and safety risks. The mining, extraction and refining of rare earths produce residues and wastes which carry health and safety risks. The residues from the extraction and refining are radioactive, while their effluent waste streams do pose pollution risks to the receiving rivers and waterways. But, as clearly elaborated in a recent report by IAEA experts, there are technologies and systems available to efficiently mitigate such risks. The risks are Rare Earth manageable. However, it is crucial that the risk and waste management procedures are strictly followed and adhered to. This is where effective monitoring and surveillance throughout the life of all such rare earths facilities is crucial. Fortunately, Malaysia's regulatory standards on rare earths follow international standards. In some areas, Malaysia's regulatory regime is even more stringent than the international guidelines. (author)

  5. A Modified Translaminar Osseous Channel-Assisted Percutaneous Endoscopic Lumbar Discectomy for Highly Migrated and Sequestrated Disc Herniations of the Upper Lumbar: Clinical Outcomes, Surgical Indications, and Technical Considerations

    Directory of Open Access Journals (Sweden)

    Zhijun Xin

    2017-01-01

    Full Text Available Objective is to describe a safe and effective percutaneous endoscopic approach for removal of highly migrated and sequestrated disc herniations of the upper lumbar spine and to report the results, surgical indications, and technical considerations of the new technique. Eleven patients who had highly migrated and sequestrated disc herniations in the upper lumbar were included in this study. A retrospective study was performed for all patients after translaminar osseous channel-assisted PELD was performed. Radiologic findings were investigated, and pre-and postoperative visual analog scale (VAS assessments for back and leg pain and Oswestry disability index (ODI evaluations were performed. Surgical outcomes were evaluated under modified MacNab criteria. All of the patients were followed for more than 1 year. The preoperative and postoperative radiologic findings revealed that the decompression of the herniated nucleus pulposus (HNP was complete. After surgery, the mean VAS scores for back and leg pain immediately improved from 8.64 (range, 7–10 and 8.00 (range, 6–10 to 2.91 (range, 2–4 and 2.27 (range, 1–3, respectively. The mean preoperative ODI was 65.58 (range, 52.2–86, which decreased to 7.51 (range, 1.8–18 at the 12-month postoperative follow-up. The MacNab scores at the final follow-up included nine excellent, one good, and one fair. The modified translaminar osseous channel-assisted PELD could be a safe and effective option for the treatment of highly migrated and sequestrated disc herniations of the upper lumbar.

  6. 77 FR 21389 - Unexpected Urgent Refugee and Migration Needs

    Science.gov (United States)

    2012-04-10

    ... April 3, 2012 Unexpected Urgent Refugee and Migration Needs Memorandum for the Secretary of State By the... 2(c)(1) of the Migration and Refugee Assistance Act of 1962 (the ``Act''), as amended, (22 U.S.C... United States Emergency Refugee and Migration Assistance Fund, for the purpose of meeting unexpected and...

  7. Mercury exposure in terrestrial birds far downstream of an historical point source

    International Nuclear Information System (INIS)

    Jackson, Allyson K.; Evers, David C.; Folsom, Sarah B.; Condon, Anne M.; Diener, John; Goodrick, Lizzie F.; McGann, Andrew J.; Schmerfeld, John; Cristol, Daniel A.

    2011-01-01

    Mercury (Hg) is a persistent environmental contaminant found in many freshwater and marine ecosystems. Historical Hg contamination in rivers can impact the surrounding terrestrial ecosystem, but there is little known about how far downstream this contamination persists. In 2009, we sampled terrestrial forest songbirds at five floodplain sites up to 137 km downstream of an historical source of Hg along the South and South Fork Shenandoah Rivers (Virginia, USA). We found that blood total Hg concentrations remained elevated over the entire sampling area and there was little evidence of decline with distance. While it is well known that Hg is a pervasive and long-lasting aquatic contaminant, it has only been recently recognized that it also biomagnifies effectively in floodplain forest food webs. This study extends the area of concern for terrestrial habitats near contaminated rivers for more than 100 km downstream from a waterborne Hg point source. - Highlights: → We report blood mercury levels for terrestrial songbirds downstream of contamination. → Blood mercury levels remain elevated above reference for at least 137 km downstream. → Trends vary based on foraging guild and migration strategy. → Mercury affects terrestrial biota farther downstream than previously documented. - Blood mercury levels of forest songbirds remain elevated above reference levels for at least 137 km downstream of historical point source.

  8. Mercury exposure in terrestrial birds far downstream of an historical point source

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, Allyson K., E-mail: allyson.jackson@briloon.org [Biodiversity Research Institute, 19 Flaggy Meadow Road, Gorham, ME 04038 (United States); Institute for Integrative Bird Behavior Studies, Department of Biology, College of William and Mary, PO Box 8795, Williamsburg, VA 23187 (United States); Evers, David C.; Folsom, Sarah B. [Biodiversity Research Institute, 19 Flaggy Meadow Road, Gorham, ME 04038 (United States); Condon, Anne M. [U.S. Fish and Wildlife Service, 6669 Short Lane, Gloucester, VA 23061 (United States); Diener, John; Goodrick, Lizzie F. [Biodiversity Research Institute, 19 Flaggy Meadow Road, Gorham, ME 04038 (United States); McGann, Andrew J. [Institute for Integrative Bird Behavior Studies, Department of Biology, College of William and Mary, PO Box 8795, Williamsburg, VA 23187 (United States); Schmerfeld, John [U.S. Fish and Wildlife Service, 6669 Short Lane, Gloucester, VA 23061 (United States); Cristol, Daniel A. [Institute for Integrative Bird Behavior Studies, Department of Biology, College of William and Mary, PO Box 8795, Williamsburg, VA 23187 (United States)

    2011-12-15

    Mercury (Hg) is a persistent environmental contaminant found in many freshwater and marine ecosystems. Historical Hg contamination in rivers can impact the surrounding terrestrial ecosystem, but there is little known about how far downstream this contamination persists. In 2009, we sampled terrestrial forest songbirds at five floodplain sites up to 137 km downstream of an historical source of Hg along the South and South Fork Shenandoah Rivers (Virginia, USA). We found that blood total Hg concentrations remained elevated over the entire sampling area and there was little evidence of decline with distance. While it is well known that Hg is a pervasive and long-lasting aquatic contaminant, it has only been recently recognized that it also biomagnifies effectively in floodplain forest food webs. This study extends the area of concern for terrestrial habitats near contaminated rivers for more than 100 km downstream from a waterborne Hg point source. - Highlights: > We report blood mercury levels for terrestrial songbirds downstream of contamination. > Blood mercury levels remain elevated above reference for at least 137 km downstream. > Trends vary based on foraging guild and migration strategy. > Mercury affects terrestrial biota farther downstream than previously documented. - Blood mercury levels of forest songbirds remain elevated above reference levels for at least 137 km downstream of historical point source.

  9. Migration chemistry

    International Nuclear Information System (INIS)

    Carlsen, L.

    1992-05-01

    Migration chemistry, the influence of chemical -, biochemical - and physico-chemical reactions on the migration behaviour of pollutants in the environment, is an interplay between the actual natur of the pollutant and the characteristics of the environment, such as pH, redox conditions and organic matter content. The wide selection of possible pollutants in combination with varying geological media, as well as the operation of different chemical -, biochemical - and physico-chemical reactions compleactes the prediction of the influence of these processes on the mobility of pollutants. The report summarizes a wide range of potential pollutants in the terrestrial environment as well as a variety of chemical -, biochemical - and physico-chemical reactions, which can be expected to influence the migration behaviour, comprising diffusion, dispersion, convection, sorption/desorption, precipitation/dissolution, transformations/degradations, biochemical reactions and complex formation. The latter comprises the complexation of metal ions as well as non-polar organics to naturally occurring organic macromolecules. The influence of the single types of processes on the migration process is elucidated based on theoretical studies. The influence of chemical -, biochemical - and physico-chemical reactions on the migration behaviour is unambiguous, as the processes apparently control the transport of pollutants in the terrestrial environment. As the simple, conventional K D concept breaks down, it is suggested that the migration process should be described in terms of the alternative concepts chemical dispersion, average-elution-time and effective retention. (AB) (134 refs.)

  10. MIGRATION – EFFECTS AND SOLUTIONS

    Directory of Open Access Journals (Sweden)

    Raluca Cruceru

    2012-12-01

    Full Text Available There are three main flows that influence workforce performance—worker migration, the dissemination of knowledge, and overseas development assistance. For the present paper we decided to deal with the analyses of these three, yet mainly migration. We considered it to be one of the most important phenomenon existent on the market at this hour and with the highest negative impact on the economic and social situation. We presented a case study regarding the situation of migration in Romania and the main candidates to Romanian intelligence imports, the main issues and possible solutions to the problems encountered.

  11. Pyroelectric field assisted ion migration induced by ultraviolet laser irradiation and its impact on ferroelectric domain inversion in lithium niobate crystals

    International Nuclear Information System (INIS)

    Ying, C. Y. J.; Mailis, S.; Daniell, G. J.; Steigerwald, H.; Soergel, E.

    2013-01-01

    The impact of UV laser irradiation on the distribution of lithium ions in ferroelectric lithium niobate single crystals has been numerically modelled. Strongly absorbed UV radiation at wavelengths of 244–305 nm produces steep temperature gradients which cause lithium ions to migrate and result in a local variation of the lithium concentration. In addition to the diffusion, here the pyroelectric effect is also taken into account which predicts a complex distribution of lithium concentration along the c-axis of the crystal: two separated lithium deficient regions on the surface and in depth. The modelling on the local lithium concentration and the subsequent variation of the coercive field are used to explain experimental results on the domain inversion of such UV treated lithium niobate crystals

  12. Philippines' downstream sector poised for growth

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This paper reports that the Philippines' downstream sector is poised for sharp growth. Despite a slip in refined products demand in recent years, Philippines products demand will rebound sharply by 2000, East-West Center (EWC), Honolulu, predicts. Philippines planned refinery expansions are expected to meet that added demand, EWC Director Fereidun Fesharaki says. Like the rest of the Asia-Pacific region, product specifications are changing, but major refiners in the area expect to meet the changes without major case outlays. At the same time, Fesharaki says, push toward deregulation will further bolster the outlook for the Philippines downstream sector

  13. Scleroglucan: Fermentative Production, Downstream Processing and Applications

    Directory of Open Access Journals (Sweden)

    Shrikant A. Survase

    2007-01-01

    Full Text Available Exopolysaccharides produced by a variety of microorganisms find multifarious industrial applications in foods, pharmaceutical and other industries as emulsifiers, stabilizers, binders, gelling agents, lubricants, and thickening agents. One such exopolysaccharide is scleroglucan, produced by pure culture fermentation from filamentous fungi of genus Sclerotium. The review discusses the properties, fermentative production, downstream processing and applications of scleroglucan.

  14. The downstream industry compared to market

    International Nuclear Information System (INIS)

    Chevallier, B.

    2010-01-01

    J.L. Schilansky introduces here the difficult question of the downstream industry compared to market in recalling the recent structural changes (behaviour of customers, behaviour of the USA- and China-governments), the increase of the European and French regulations, the climatic change and the conjectural impact of the crisis on the refining industry. (O.M.)

  15. Migrating Worker

    DEFF Research Database (Denmark)

    Hansen, Hans

    This is the preliminary report on the results obtained in the Migrating Worker-project. This project was initiated by the Danish Ministry of Finance with the aim of illustrating the effects of the 1408/71 agreement and the bilateral double taxation agreements Denmark has with the countries included...

  16. Dateline Migration.

    Science.gov (United States)

    Tomasi, Lydio E., Ed.

    1995-01-01

    Presents data on international migration and its effects in and between various countries in North America, Europe, and Africa. Discussions include refugee, immigrant, and migrant worker flows; the legal, political, and social problems surrounding immigrants; alien terrorism and law enforcement problems; and migrant effects on education, social…

  17. India's Downstream Petroleum Sector

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    This study provides a holistic examination of pricing and investment dynamics in India's downstream petroleum sector. It analyses the current pricing practices, highlights the tremendous fiscal cost of current pricing and regulatory arrangements, and examines the sectoral investment dynamics. It also looks at potential paths towards market-based reform along which the Indian government may move, while at the same time protecting energy market access for India's large poor population.

  18. Modification of meander migration by bank failures

    Science.gov (United States)

    Motta, D.; Langendoen, E. J.; Abad, J. D.; García, M. H.

    2014-05-01

    Meander migration and planform evolution depend on the resistance to erosion of the floodplain materials. To date, research to quantify meandering river adjustment has largely focused on resistance to erosion properties that vary horizontally. This paper evaluates the combined effect of horizontal and vertical floodplain material heterogeneity on meander migration by simulating fluvial erosion and cantilever and planar bank mass failure processes responsible for bank retreat. The impact of stream bank failures on meander migration is conceptualized in our RVR Meander model through a bank armoring factor associated with the dynamics of slump blocks produced by cantilever and planar failures. Simulation periods smaller than the time to cutoff are considered, such that all planform complexity is caused by bank erosion processes and floodplain heterogeneity and not by cutoff dynamics. Cantilever failure continuously affects meander migration, because it is primarily controlled by the fluvial erosion at the bank toe. Hence, it impacts migration rates and meander shapes through the horizontal and vertical distribution of erodibility of floodplain materials. Planar failures are more episodic. However, in floodplain areas characterized by less cohesive materials, they can affect meander evolution in a sustained way and produce preferential migration patterns. Model results show that besides the hydrodynamics, bed morphology and horizontal floodplain heterogeneity, floodplain stratigraphy can significantly affect meander evolution, both in terms of migration rates and planform shapes. Specifically, downstream meander migration can either increase or decrease with respect to the case of a homogeneous floodplain; lateral migration generally decreases as result of bank protection due to slump blocks; and the effect on bend skewness depends on the location and volumes of failed bank material caused by cantilever and planar failures along the bends, with possible achievement of

  19. A preference for migration

    OpenAIRE

    Stark, Oded

    2007-01-01

    At least to some extent migration behavior is the outcome of a preference for migration. The pattern of migration as an outcome of a preference for migration depends on two key factors: imitation technology and migration feasibility. We show that these factors jointly determine the outcome of a preference for migration and we provide examples that illustrate how the prevalence and transmission of a migration-forming preference yield distinct migration patterns. In particular, the imitation of...

  20. DOWNSTREAM ECOCIDE FROM UPSTREAM WATER PIRACY

    OpenAIRE

    Miah Muhammad Adel

    2012-01-01

    Upstream India and downstream Bangladesh share more than 50 international rivers. India has set up water diversion constructions in more than 50% of these rivers, the largest one being on the Bangladeshâs northwest upon the Ganges River, puts Bangladeshâs Gangetic ecosystem at stake. In some border rivers, India has set up groins on her side of river banks. Also, Indian side pumps Bangladesh river water stealthily from border-rivers. Further, India is constructing another dam and reservoir up...

  1. The commercialization of migration.

    Science.gov (United States)

    Abrera-mangahas, M A

    1989-01-01

    International migration is not new to the Philippines. In the recent outflow of contract workers to the Middle East, there is a shift from individual and family initiated migrations to the more organized, highly commercial variety. While profit-taking intermediaries have played some role in the past, the increase in the number and influence of these intermediaries has altered the story of migration decision-making. In 1975, the signing of the bilateral labor agreement between the governments of Iran and the Philippines signalled the rising demand for Filipino contract workers. From 1970 to 1975, the number of Asian migrant workers in the Gulf countries rose from about 120,000 to 370,000. These figures rose dramatically to 3.3 million in 1985. The growing share of organized and commercialized migration has altered migration decision making. Primarily, intermediaries are able to broaden access to foreign job and high wage opportunities. Commercialization effectively raises the transaction costs for contract migration. Studies on recruitment costs and fees show that self-solicited foreign employment costs less than employment obtained through recruitment agents and intermediaries. The difference in the 2 prices is due, not only to overhead costs of intermediation, but more importantly to the rent exacted by agents from having job information and placement rights. In the Philippines in October 1987 the average placement fee was P8000, greatly exceeding the mandated maximum fee level of P5000. This average is understated because the computation includes the 17% who do not pay any fees. The widespread and popular view of recruitment intermediaries is negative, dominated by images of abuses and victims. Private intermediaries and the government bureaucracy need each other. Intermediaries need government; their consistent demand for incentives and protection is indicative. On the other hand, government expands its supervision of control of overseas employment via the

  2. DARHT-II Downstream Transport Beamline

    International Nuclear Information System (INIS)

    Westenskow, G A; Bertolini, L R; Duffy, P T; Paul, A C

    2001-01-01

    This paper describes the mechanical design of the downstream beam transport line for the second axis of the Dual Axis Radiographic Hydrodynamic Test (DARHT II) Facility. The DARHT-II project is a collaboration between LANL, LBNL and LLNL. DARHT II is a 18.4-MeV, 2000-Amperes, 2-(micro)sec linear induction accelerator designed to generate short bursts of x-rays for the purpose of radiographing dense objects. The downstream beam transport line is approximately 22-meter long region extending from the end of the accelerator to the bremsstrahlung target. Within this proposed transport line there are 12 conventional solenoid, quadrupole and dipole magnets; as well as several specialty magnets, which transport and focus the beam to the target and to the beam dumps. There are two high power beam dumps, which are designed to absorb 80-kJ per pulse during accelerator start-up and operation. Aspects of the mechanical design of these elements are presented

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

    International Nuclear Information System (INIS)

    Travade, F.; Larinier, M.

    1992-01-01

    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

  4. Downstream lightening and upward heavying, sorting of sediments of uniform grain size but differing in density

    Science.gov (United States)

    Viparelli, E.; Solari, L.; Hill, K. M.

    2014-12-01

    Downstream fining, i.e. the tendency for a gradual decrease in grain size in the downstream direction, has been observed and studied in alluvial rivers and in laboratory flumes. Laboratory experiments and field observations show that the vertical sorting pattern over a small Gilbert delta front is characterized by an upward fining profile, with preferential deposition of coarse particles in the lowermost part of the deposit. The present work is an attempt to answer the following questions. Are there analogous sorting patterns in mixtures of sediment particles having the same grain size but differing density? To investigate this, we performed experiments at the Hydrosystems Laboratory at the University of Illinois at Urbana-Champaign. During the experiments a Gilbert delta formed and migrated downstream allowing for the study of transport and sorting processes on the surface and within the deposit. The experimental results show 1) preferential deposition of heavy particles in the upstream part of the deposit associated with a pattern of "downstream lightening"; and 2) a vertical sorting pattern over the delta front characterized by a pattern of "upward heavying" with preferential deposition of light particles in the lowermost part of the deposit. The observed downstream lightening is analogous of the downstream fining with preferential deposition of heavy (coarse) particles in the upstream part of the deposit. The observed upward heavying was unexpected because, considering the particle mass alone, the heavy (coarse) particles should have been preferentially deposited in the lowermost part of the deposit. Further, the application of classical fractional bedload transport relations suggests that in the case of mixtures of particles of uniform size and different densities equal mobility is not approached. We hypothesize that granular physics mechanisms traditionally associated with sheared granular flows may be responsible for the observed upward heavying and for the

  5. Downstream process options for the ABE fermentation.

    Science.gov (United States)

    Friedl, Anton

    2016-05-01

    Butanol is a very interesting substance both for the chemical industry and as a biofuel. The classical distillation process for the removal of butanol is far too energy demanding, at a factor of 220% of the energy content of butanol. Alternative separation processes studied are hybrid processes of gas-stripping, liquid-liquid extraction and pervaporation with distillation and a novel adsorption/drying/desorption hybrid process. Compared with the energy content of butanol, the resulting energy demand for butanol separation and concentration of optimized hybrid processes is 11%-22% for pervaporation/distillation and 11%-17% for liquid-liquid extraction/distillation. For a novel adsorption/drying/desorption process, the energy demand is 9.4%. But all downstream process options need further proof of industrial applicability. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. The jet membrane-experiment: downstream sampling

    International Nuclear Information System (INIS)

    Campargue, R.

    1976-01-01

    The invasion separation effect of the free jet structure was found in 1966 at Saclay. In the Downstream Sampling Configuration patended by Campargue (1967), the light fraction is withdrawn from the supersonic central core, by skimming the separating free jet. From experimental and theoretical results obtained for gas and isotopic mixtures, the following points linked to operation and equipment costs, are considered: system description; influence of mass ratio, expansion ratio, nature of separating gas, ratio of upflow to separating jet flow, rarefaction. Fron an uninteresting aspect of Jet Membrane (elimination of background penetration), a new principle has been discovered to produce nozzle beams which may be of great interest for other separation processes involving free jets and/or molecular beams [fr

  7. 76 FR 14271 - Unexpected Urgent Refugee and Migration Needs Related to Libya

    Science.gov (United States)

    2011-03-16

    ... March 7, 2011 Unexpected Urgent Refugee and Migration Needs Related to Libya Memorandum for the... States, including section 2(c)(1) of the Migration and Refugee Assistance Act of 1962 (the ``Act''), as... million from the United States Emergency Refugee and Migration Assistance Fund, for the purpose of meeting...

  8. 75 FR 67013 - Unexpected Urgent Refugee and Migration Needs Resulting from Violence in Kyrgyzstan

    Science.gov (United States)

    2010-11-01

    ... August 26, 2010 Unexpected Urgent Refugee and Migration Needs Resulting from Violence in Kyrgyzstan... laws of the United States, including section 2(c)(1) of the Migration and Refugee Assistance Act of... amount not to exceed $9.5 million from the United States Emergency Refugee and Migration Assistance Fund...

  9. Stereotactic core needle breast biopsy marker migration: An analysis of factors contributing to immediate marker migration.

    Science.gov (United States)

    Jain, Ashali; Khalid, Maria; Qureshi, Muhammad M; Georgian-Smith, Dianne; Kaplan, Jonah A; Buch, Karen; Grinstaff, Mark W; Hirsch, Ariel E; Hines, Neely L; Anderson, Stephan W; Gallagher, Katherine M; Bates, David D B; Bloch, B Nicolas

    2017-11-01

    To evaluate breast biopsy marker migration in stereotactic core needle biopsy procedures and identify contributing factors. This retrospective study analyzed 268 stereotactic biopsy markers placed in 263 consecutive patients undergoing stereotactic biopsies using 9G vacuum-assisted devices from August 2010-July 2013. Mammograms were reviewed and factors contributing to marker migration were evaluated. Basic descriptive statistics were calculated and comparisons were performed based on radiographically-confirmed marker migration. Of the 268 placed stereotactic biopsy markers, 35 (13.1%) migrated ≥1 cm from their biopsy cavity. Range: 1-6 cm; mean (± SD): 2.35 ± 1.22 cm. Of the 35 migrated biopsy markers, 9 (25.7%) migrated ≥3.5 cm. Patient age, biopsy pathology, number of cores, and left versus right breast were not associated with migration status (P> 0.10). Global fatty breast density (P= 0.025) and biopsy in the inner region of breast (P = 0.031) were associated with marker migration. Superior biopsy approach (P= 0.025), locally heterogeneous breast density, and t-shaped biopsy markers (P= 0.035) were significant for no marker migration. Multiple factors were found to influence marker migration. An overall migration rate of 13% supports endeavors of research groups actively developing new biopsy marker designs for improved resistance to migration. • Breast biopsy marker migration is documented in 13% of 268 procedures. • Marker migration is affected by physical, biological, and pathological factors. • Breast density, marker shape, needle approach etc. affect migration. • Study demonstrates marker migration prevalence; marker design improvements are needed.

  10. The Globalisation of migration

    OpenAIRE

    Milan Mesić

    2002-01-01

    The paper demonstrates that contemporary international migration is a constitutive part of the globalisation process. After defining the concepts of globalisation and the globalisation of migration, the author discusses six key themes, linking globalisation and international migration (“global cities”, the scale of migration; diversification of migration flows; globalisation of science and education; international migration and citizenship; emigrant communities and new identities). First, in ...

  11. Installaton of a fish migration channel for spawning at Itaipu

    International Nuclear Information System (INIS)

    Borghetti, J.R.; Perez Chena, D.; Nogueira, S.V.G.

    1993-01-01

    The objective of installing a fish migration channel for spawning at the Itaipu hydroelectric station on the Parana river between Brazil and Paraguay is to improve fish recovery downstream from the dam. Preliminary data from the first phase has proved the efficiency of an experimental project, with the entry and ascendancy of fish in a migration channel ladder. These data now provide the technical basis for implementation of the complementary spawning channel stage. (author)

  12. Downstream Processing of Synechocystis for Biofuel Production

    Science.gov (United States)

    Sheng, Jie

    Lipids and free fatty acids (FFA) from cyanobacterium Synechocystis can be used for biofuel (e.g. biodiesel or renewable diesel) production. In order to utilize and scale up this technique, downstream processes including culturing and harvest, cell disruption, and extraction were studied. Several solvents/solvent systems were screened for lipid extraction from Synechocystis. Chloroform + methanol-based Folch and Bligh & Dyer methods were proved to be "gold standard" for small-scale analysis due to their highest lipid recoveries that were confirmed by their penetration of the cell membranes, higher polarity, and stronger interaction with hydrogen bonds. Less toxic solvents, such as methanol and MTBE, or direct transesterification of biomass (without preextraction step) gave only slightly lower lipid-extraction yields and can be considered for large-scale application. Sustained exposure to high and low temperature extremes severely lowered the biomass and lipid productivity. Temperature stress also triggered changes of lipid quality such as the degree of unsaturation; thus, it affected the productivities and quality of Synechocystis-derived biofuel. Pulsed electric field (PEF) was evaluated for cell disruption prior to lipid extraction. A treatment intensity > 35 kWh/m3 caused significant damage to the plasma membrane, cell wall, and thylakoid membrane, and it even led to complete disruption of some cells into fragments. Treatment by PEF enhanced the potential for the low-toxicity solvent isopropanol to access lipid molecules during subsequent solvent extraction, leading to lower usage of isopropanol for the same extraction efficiency. Other cell-disruption methods also were tested. Distinct disruption effects to the cell envelope, plasma membrane, and thylakoid membranes were observed that were related to extraction efficiency. Microwave and ultrasound had significant enhancement of lipid extraction. Autoclaving, ultrasound, and French press caused significant

  13. Microbial production of scleroglucan and downstream processing

    Directory of Open Access Journals (Sweden)

    Natalia Alejandra Castillo

    2015-10-01

    Full Text Available Synthetic petroleum-based polymers and natural plant polymers have the disadvantage of restricted sources, in addition to the non-biodegradability of the former ones. In contrast, eco-sustainable microbial polysaccharides, of low-cost and standardized production, represent an alternative to address this situation. With a strong global market, they attracted worldwide attention because of their novel and unique physico-chemical properties as well as varied industrial applications, and many of them are promptly becoming economically competitive. Scleroglucan, a beta-1,3-beta-1,6-glucan secreted by Sclerotium fungi, exhibits high potential for commercialization and may show different branching frequency, side-chain length and/or molecular weight depending on the producing strain or culture conditions. Water-solubility, viscosifying ability and wide stability over temperature, pH and salinity make scleroglucan useful for different biotechnological (enhanced oil recovery, food additives, drug delivery, cosmetic and pharmaceutical products, biocompatible materials, etc., and biomedical (immunoceutical, antitumor, etc. applications. It can be copiously produced at bioreactor scale under standardized conditions, where a high EPS concentration normally governs the process optimization. Operative and nutritional conditions, as well as the incidence of scleroglucan downstream processing will be discussed in this chapter. The relevance of using standardized inocula from selected strains and experiences concerning the intricate scleroglucan scaling-up will be also herein outlined.

  14. Back-flow ripples in troughs downstream of unit bars: Formation, preservation and value for interpreting flow conditions

    OpenAIRE

    Herbert, Christopher; Alexander, Jan; Martinez De Alvaro, Maria

    2015-01-01

    Back-flow ripples are bedforms created within the lee-side eddy of a larger bedform with migration directions opposed or oblique to that of the host bedform. In the flume experiments described in this article, back-flow ripples formed in the trough downstream of a unit bar and changed with mean flow velocity; varying from small incipient back-flow ripples at low velocities, to well-formed back-flow ripples with greater velocity, to rapidly migrating transient back-flow ripples formed at the g...

  15. A coupled modelling effort to study the fate of contaminated sediments downstream of the Coles Hill deposit, Virginia, USA

    Directory of Open Access Journals (Sweden)

    C. F. Castro-Bolinaga

    2015-03-01

    Full Text Available This paper presents the preliminary results of a coupled modelling effort to study the fate of tailings (radioactive waste-by product downstream of the Coles Hill uranium deposit located in Virginia, USA. The implementation of the overall modelling process includes a one-dimensional hydraulic model to qualitatively characterize the sediment transport process under severe flooding conditions downstream of the potential mining site, a two-dimensional ANSYS Fluent model to simulate the release of tailings from a containment cell located partially above the local ground surface into the nearby streams, and a one-dimensional finite-volume sediment transport model to examine the propagation of a tailings sediment pulse in the river network located downstream. The findings of this investigation aim to assist in estimating the potential impacts that tailings would have if they were transported into rivers and reservoirs located downstream of the Coles Hill deposit that serve as municipal drinking water supplies.

  16. 5 X 5 rod bundle flow field measurements downstream a PWR spacer grid

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Higor F.P.; Silva, Vitor V A.; Santos, André A.C.; Veloso, Maria A.F., E-mail: higorfabiano@gmail.com, E-mail: mdora@nuclear.ufmg.br, E-mail: vitors@cdtn.br, E-mail: aacs@cdtn.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil); Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2017-07-01

    The spacer grids are structures present in nuclear fuel assembly of Pressurized Water Reactors (PWR). They play an important structural role and also assist in heat removal through the assembly by promoting increased turbulence of the flow. Understanding the flow dynamics downstream the spacer grid is paramount for fuel element design and analysis. This paper presents water flow velocity profiles measurements downstream a spacer grid in a 5 x 5 rod bundle test rig with the objective of highlighting important fluid dynamic behavior near the grid and supplying data for CFD simulation validation. These velocity profiles were obtained at two different heights downstream the spacer grid using a LDV (Laser Doppler Velocimetry) through the top of test rig. The turbulence intensities and patterns of the swirl and cross flow were evaluated. The tests were conducted for Reynolds numbers ranging from 1.8 x 10{sup 4} to 5.4 x 10{sup 4}. This experimental research was carried out in thermo-hydraulics laboratory of Nuclear Technology Development Center – CDTN. Results show great repeatability and low uncertainties (< 1.24 %). Details of the flow field show how the mixture and turbulence induced by the spacer grid quickly decays downstream the spacer grid. It is shown that the developed methodology can supply high resolution low uncertainty results that can be used for validation of CFD simulations. (author)

  17. 5 X 5 rod bundle flow field measurements downstream a PWR spacer grid

    International Nuclear Information System (INIS)

    Castro, Higor F.P.; Silva, Vitor V A.; Santos, André A.C.; Veloso, Maria A.F.

    2017-01-01

    The spacer grids are structures present in nuclear fuel assembly of Pressurized Water Reactors (PWR). They play an important structural role and also assist in heat removal through the assembly by promoting increased turbulence of the flow. Understanding the flow dynamics downstream the spacer grid is paramount for fuel element design and analysis. This paper presents water flow velocity profiles measurements downstream a spacer grid in a 5 x 5 rod bundle test rig with the objective of highlighting important fluid dynamic behavior near the grid and supplying data for CFD simulation validation. These velocity profiles were obtained at two different heights downstream the spacer grid using a LDV (Laser Doppler Velocimetry) through the top of test rig. The turbulence intensities and patterns of the swirl and cross flow were evaluated. The tests were conducted for Reynolds numbers ranging from 1.8 x 10"4 to 5.4 x 10"4. This experimental research was carried out in thermo-hydraulics laboratory of Nuclear Technology Development Center – CDTN. Results show great repeatability and low uncertainties (< 1.24 %). Details of the flow field show how the mixture and turbulence induced by the spacer grid quickly decays downstream the spacer grid. It is shown that the developed methodology can supply high resolution low uncertainty results that can be used for validation of CFD simulations. (author)

  18. Les questions de migrations internationales

    Science.gov (United States)

    Samman, Mouna Liliane

    1993-03-01

    International migrations have growing implications for both countries of origin and countries of destination. In the latter, the presence of foreigners and of members of their families today creates problems of integration, causes argument and brings mounting xenophobia. Paralleling political, economic and social measures taken by public authorities to respond to these difficulties, education needs to assist in defusing the resulting social tensions by preparing the minds of learners and helping to develop new attitudes. In particular, when educational programmes address questions of international migration, these should be treated in the framework of historical evolution so that their real significance and their true temporal and spatial dimensions become apparent. It is also important that the growing interdependence between countries should be made plain, that national history should be placed in its international context, and that the true consequences of these developments should be made clear. In this context, learners need to be acquainted with Human Rights, thereby stressing universal moral values and the role of the individual. Lastly, questions relating to international migration are usually presented in the media in a selective and partial manner, and the young people who take in this information often accept the hasty judgments which are made of situations as proven facts. This is why all teaching about international migration needs to be considered or reconsidered in the light of the complementary or competing actions of the media.

  19. Downstream-based Scheduling for Energy Conservation in Green EPONs

    KAUST Repository

    Chen, Shen; Dhaini, Ahmad R.; Ho, Pin-Han; Shihada, Basem; Shen, Gangxiang; Lin, Chih-Hao

    2012-01-01

    the ONU sleep time, it jeopardizes the quality of service (QoS) performance of the network, especially for downstream traffic in case the overlapping is based on the upstream time slot. In this paper, we study the downstream traffic performance in green

  20. A floating trap for sampling downstream migrant fishes.

    Science.gov (United States)

    Carl E. McLemore; Fred H. Everest; William R. Humphreys; Mario F. Solazzi

    1989-01-01

    Fishery scientists and managers are interested in obtaining information about downstream movements of fish species for biological and economic reasons. Different types of nets and traps have been used for this purpose with only partial success. The floating, self-cleaning downstream migrant trap described here proved successful for sampling several salmoniform and...

  1. Human neutrophils facilitate tumor cell transendothelial migration.

    LENUS (Irish Health Repository)

    Wu, Q D

    2012-02-03

    Tumor cell extravasation plays a key role in tumor metastasis. However, the precise mechanisms by which tumor cells migrate through normal vascular endothelium remain unclear. In this study, using an in vitro transendothelial migration model, we show that human polymorphonuclear neutrophils (PMN) assist the human breast tumor cell line MDA-MB-231 to cross the endothelial barrier. We found that tumor-conditioned medium (TCM) downregulated PMN cytocidal function, delayed PMN apoptosis, and concomitantly upregulated PMN adhesion molecule expression. These PMN treated with TCM attached to tumor cells and facilitated tumor cell migration through different endothelial monolayers. In contrast, MDA-MB-231 cells alone did not transmigrate. FACScan analysis revealed that these tumor cells expressed high levels of intercellular adhesion molecule-1 (ICAM-1) but did not express CD11a, CD11b, or CD18. Blockage of CD11b and CD18 on PMN and of ICAM-1 on MDA-MB-231 cells significantly attenuated TCM-treated, PMN-mediated tumor cell migration. These tumor cells still possessed the ability to proliferate after PMN-assisted transmigration. These results indicate that TCM-treated PMN may serve as a carrier to assist tumor cell transendothelial migration and suggest that tumor cells can exploit PMN and alter their function to facilitate their extravasation.

  2. Pushing the pace of tree species migration.

    Directory of Open Access Journals (Sweden)

    Eli D Lazarus

    Full Text Available Plants and animals have responded to past climate changes by migrating with habitable environments, sometimes shifting the boundaries of their geographic ranges by tens of kilometers per year or more. Species migrating in response to present climate conditions, however, must contend with landscapes fragmented by anthropogenic disturbance. We consider this problem in the context of wind-dispersed tree species. Mechanisms of long-distance seed dispersal make these species capable of rapid migration rates. Models of species-front migration suggest that even tree species with the capacity for long-distance dispersal will be unable to keep pace with future spatial changes in temperature gradients, exclusive of habitat fragmentation effects. Here we present a numerical model that captures the salient dynamics of migration by long-distance dispersal for a generic tree species. We then use the model to explore the possible effects of assisted colonization within a fragmented landscape under a simulated tree-planting scheme. Our results suggest that an assisted-colonization program could accelerate species-front migration rates enough to match the speed of climate change, but such a program would involve an environmental-sustainability intervention at a massive scale.

  3. Numerical Simulation of Missouri River Bed Evolution Downstream of Gavins Point Dam

    Science.gov (United States)

    Sulaiman, Z. A.; Blum, M. D.; Lephart, G.; Viparelli, E.

    2016-12-01

    The Missouri River originates in the Rocky Mountains in western Montana and joins the Mississippi River near Saint Louis, Missouri. In the 1900s dam construction and river engineering works, such as river alignment, narrowing and bank protections were performed in the Missouri River basin to control the flood flows, ensure navigation and use the water for agricultural, industrial and municipal needs, for the production of hydroelectric power generation and for recreation. These projects altered the flow and the sediment transport regimes in the river and the exchange of sediment between the river and the adjoining floodplain. Here we focus on the long term effect of dam construction and channel narrowing on the 1200 km long reach of the Missouri River between Gavins Point Dam, Nebraska and South Dakota, and the confluence with the Mississippi River. Field observations show that two downstream migrating waves of channel bed degradation formed in this reach in response to the changes in flow regime, sediment load and channel geometry. We implemented a one dimensional morphodynamic model for large, low slope sand bed rivers, we validated the model at field scale by comparing the numerical results with the available field data and we use the model to 1) predict the magnitude and the migration rate of the waves of degradation at engineering time scales ( 150 years into the future), 2) quantify the changes in the sand load delivered to the Mississippi River, where field observations at Thebes, i.e. downstream of Saint Louis, suggest a decline in the mean annual sand load in the past 50 years, and 3) identify the role of the main tributaries - Little Sioux River, Platte River and Kansas River - on the wave migration speed and the annual sand load in the Missouri River main channel.

  4. Migration of gases through argillaceous rocks

    International Nuclear Information System (INIS)

    Tomlinson, M.J.

    1988-11-01

    Research literature relating to laboratory and field experimentation and numerical modelling of gas transport in argillaceous geological materials has been examined. A data base has been formed to assist simulation of gas migration behaviour from proposed underground nuclear waste repositories. (author)

  5. 76 FR 35719 - Unexpected Urgent Refugee and Migration Needs Related to Libya and C[ocirc]te d'Ivoire

    Science.gov (United States)

    2011-06-20

    ... June 8, 2011 Unexpected Urgent Refugee and Migration Needs Related to Libya and C[ocirc]te d'Ivoire... laws of the United States, including section 2(c)(1) of the Migration and Refugee Assistance Act of... amount not to exceed $15 million from the United States Emergency Refugee and Migration Assistance Fund...

  6. MANAGING MIGRATION: TURKISH PERSPECTIVE

    Directory of Open Access Journals (Sweden)

    İhsan GÜLAY

    2018-04-01

    Full Text Available Conducting migration studies is of vital importance to Turkey, a country which has been experiencing migration throughout history due to its “open doors policy”. The objective of this study is to evaluate the strategic management of migration in Turkey in order to deal with the issue of migration. The main focus of the study is Syrian migrants who sought refuge in Turkey due to the civil war that broke out in their country in April 2011. This study demonstrates the policies and processes followed by Turkey for Syrian migration flow in terms of the social acceptance and harmonisation of the migrants within a democratic environment. The study addresses some statistical facts and issues related to Syrian migration as it has become an integral part of daily life in Turkey. The study also reviews how human rights are protected in the migration process. The study will provide insights for developing sound strategic management policies for the migration issue.

  7. Migration and revolution

    Directory of Open Access Journals (Sweden)

    Nando Sigona

    2012-06-01

    Full Text Available The Arab Spring has not radically transformed migration patterns in the Mediterranean, and the label ‘migration crisis’ does not do justice to the composite and stratified reality.

  8. Downstream passage and impact of turbine shutdowns on survival of silver American Eels at five hydroelectric dams on the Shenandoah River

    Science.gov (United States)

    Eyler, Sheila; Welsh, Stuart A.; Smith, David R.; Rockey, Mary

    2016-01-01

    Hydroelectric dams impact the downstream migrations of silver American Eels Anguilla rostrata via migratory delays and turbine mortality. A radiotelemetry study of American Eels was conducted to determine the impacts of five run-of-the-river hydroelectric dams located over a 195-km stretch of the Shenandoah River, Virginia–West Virginia, during fall 2007–summer 2010. Overall, 96 radio-tagged individuals (mean TL = 85.4 cm) migrated downstream past at least one dam during the study. Most American Eels passed dams relatively quickly; over half (57.9%) of the dam passage events occurred within 1 h of reaching a dam, and most (81.3%) occurred within 24 h of reaching the dam. Two-thirds of the dam passage events occurred via spill, and the remaining passage events were through turbines. Migratory delays at dams were shorter and American Eels were more likely to pass via spill over the dam during periods of high river discharge than during low river discharge. The extent of delay in migration did not differ between the passage routes (spill versus turbine). Twenty-eight American Eels suffered turbine-related mortality, which occurred at all five dams. Mortality rates for eels passing through turbines ranged from 15.8% to 40.7% at individual dams. Overall project-specific mortality rates (with all passage routes combined) ranged from 3.0% to 14.3%. To protect downstream-migrating American Eels, nighttime turbine shutdowns (1800–0600 hours) were implemented during September 15–December 15. Fifty percent of all downstream passage events in the study occurred during the turbine shutdown period. Implementation of the seasonal turbine shutdown period reduced cumulative mortality from 63.3% to 37.3% for American Eels passing all five dams. Modifying the turbine shutdown period to encompass more dates in the spring and linking the shutdowns to environmental conditions could provide greater protection to downstream-migrating American Eels.

  9. Population, migration and urbanization.

    Science.gov (United States)

    1982-06-01

    Despite recent estimates that natural increase is becoming a more important component of urban growth than rural urban transfer (excess of inmigrants over outmigrants), the share of migration in the total population growth has been consistently increasing in both developed and developing countries. From a demographic perspective, the migration process involves 3 elements: an area of origin which the mover leaves and where he or she is considered an outmigrant; the destination or place of inmigration; and the period over which migration is measured. The 2 basic types of migration are internal and international. Internal migration consists of rural to urban migration, urban to urban migration, rural to rural migration, and urban to rural migration. Among these 4 types of migration various patterns or processes are followed. Migration may be direct when the migrant moves directly from the village to the city and stays there permanently. It can be circular migration, meaning that the migrant moves to the city when it is not planting season and returns to the village when he is needed on the farm. In stage migration the migrant makes a series of moves, each to a city closer to the largest or fastest growing city. Temporary migration may be 1 time or cyclical. The most dominant pattern of internal migration is rural urban. The contribution of migration to urbanization is evident. For example, the rapid urbanization and increase in urban growth from 1960-70 in the Republic of Korea can be attributed to net migration. In Asia the largest component of the population movement consists of individuals and groups moving from 1 rural location to another. Recently, because urban centers could no longer absorb the growing number of migrants from other places, there has been increased interest in the urban to rural population redistribution. This reverse migration also has come about due to slower rates of employment growth in the urban centers and improved economic opportunities

  10. [Internal migration studies].

    Science.gov (United States)

    Stpiczynski, T

    1986-10-01

    Recent research on internal migration in Poland is reviewed. The basic sources of data, consisting of censuses or surveys, are first described. The author discusses the relationship between migration studies and other sectors of the national economy, and particularly the relationship between migration and income.

  11. Spatio-temporal migration patterns of Pacific salmon smolts in rivers and coastal marine waters.

    Directory of Open Access Journals (Sweden)

    Michael C Melnychuk

    Full Text Available BACKGROUND: Migrations allow animals to find food resources, rearing habitats, or mates, but often impose considerable predation risk. Several behavioural strategies may reduce this risk, including faster travel speed and taking routes with shorter total distance. Descriptions of the natural range of variation in migration strategies among individuals and populations is necessary before the ecological consequences of such variation can be established. METHODOLOGY/PRINCIPAL FINDINGS: Movements of tagged juvenile coho, steelhead, sockeye, and Chinook salmon were quantified using a large-scale acoustic tracking array in southern British Columbia, Canada. Smolts from 13 watersheds (49 watershed/species/year combinations were tagged between 2004-2008 and combined into a mixed-effects model analysis of travel speed. During the downstream migration, steelhead were slower on average than other species, possibly related to freshwater residualization. During the migration through the Strait of Georgia, coho were slower than steelhead and sockeye, likely related to some degree of inshore summer residency. Hatchery-reared smolts were slower than wild smolts during the downstream migration, but after ocean entry, average speeds were similar. In small rivers, downstream travel speed increased with body length, but in the larger Fraser River and during the coastal migration, average speed was independent of body length. Smolts leaving rivers located towards the northern end of the Strait of Georgia ecosystem migrated strictly northwards after ocean entry, but those from rivers towards the southern end displayed split-route migration patterns within populations, with some moving southward. CONCLUSIONS/SIGNIFICANCE: Our results reveal a tremendous diversity of behavioural migration strategies used by juvenile salmon, across species, rearing histories, and habitats, as well as within individual populations. During the downstream migration, factors that had strong

  12. Wave and particle evolution downstream of quasi-perpendicular shocks

    Science.gov (United States)

    Mckean, M. E.; Omidi, N.; Krauss-Varban, D.; Karimabadi, H.

    1995-01-01

    Distributions of ions heated in quasi-perpendicular bow shocks have large perpendicular temperature anisotropies that provide free energy for the growth of Alfven ion cyclotron (AIC) and mirror waves. These modes are often obsreved in the Earth's magnetosheath. Using two-dimensional hybrid simulations, we show that these waves are produced near the shock front and convected downstream rather than being produced locally downstream. The wave activity reduces the proton anisotropy to magnetosheath levels within a few tens of gyroradii of the shock but takes significantly longer to reduce the anisotropy of He(++) ions. The waves are primarily driven by proton anisotropy and the dynamics of the helium ions is controlled by the proton waves. Downstream of high Mach number shocks, mirror waves compete effectively with AIC waves. Downstream of low Mach number shocks, AIC waves dominate.

  13. Social networks in the migration process: empirical evidence on chain migration in India.

    Science.gov (United States)

    Banerjee, B

    1983-01-01

    This study, based on interviews with 1615 migrant heads of household in Delhi, was concerned with interactions between labor migrants and their urban-based contacts. 86% of the rural migrants reported having relatives and/or covillagers living in Delhi at the time of their arrival, and virtually all received some form of assistance from their contacts. A preference for assistance from relatives rather than covillagers was noted, suggesting that migrants regarded kinship bonds as stronger than village and caste ties. However, covillagers tended to be contacted if relatives failed to secure a job for the new migrants within a reasonable time. The moves of only 17% of the sample could be classified under delayed family migration (relocation of family members in lagged stages). The tendency for traditional norms to be relaxed in an urban setting is reflected in the finding that the places of origin of migrants and their urban-based relatives differed in about half the cases that involved assistance from relatives. In addition, 13% of migrants violated traditional norms by seeking assistance from female agnates and kin affinally linked through these women. The most common pattern of assistance provided by both relatives and covillagers included room, food, and job search; however, new migrants tended to prefer to obtain board and lodging from relatives. Migrants helped by primary male agnates were twice as likely to receive money as those helped by other relatives. A consequence of chain migration is the concentration of persons from the same village or kinship network in particular occupations. 36% of the wage employees in the sample had relatives and/or covillagers working for the same employer. This suggests that migration induced by urban-based contacts (accounting for 42% of the migration in this sample) will be low if the sectors in which job opportunities are expanding are dominated by nonmigrants. Given the prevalence of chain migration, the contribution of

  14. Downstream-based Scheduling for Energy Conservation in Green EPONs

    KAUST Repository

    Chen, Shen

    2012-05-01

    Maximizing the optical network unit’s (ONU) sleep time is an effective approach for achieving maximum energy conservation in green Ethernet passive optical networks (EPONs). While overlapping downstream and upstream ONU transmissions can maximize the ONU sleep time, it jeopardizes the quality of service (QoS) performance of the network, especially for downstream traffic in case the overlapping is based on the upstream time slot. In this paper, we study the downstream traffic performance in green EPONs under the limited service discipline and the upstream-based overlapped time window. Specifically, we first derive the expected mean packet delay, and then present a closed-form expression of the ONU sleep time, setting identical upstream/downstream transmission cycle times based on a maximum downstream traffic delay re-quirement. With the proposed system model, we present a novel downstream bandwidth allocation scheme for energy conservation in green EPONs. Simulation results verify the proposed model and highlight the advantages of our scheme over conventional approaches.

  15. Control of Delta Avulsion by Downstream Sediment Sinks

    Science.gov (United States)

    Salter, Gerard; Paola, Chris; Voller, Vaughan R.

    2018-01-01

    Understanding how fluxes are partitioned at delta bifurcations is critical for predicting patterns of land loss and gain in deltas worldwide. Although the dynamics of river deltas are influenced from both upstream and downstream, previous studies of bifurcations have focused on upstream controls. Using a quasi-1-D bifurcation model, we show that flow switching in bifurcations is strongly influenced by downstream sediment sinks. We find that coupling between upstream and downstream feedbacks can lead to oscillations in water and sediment flux partitioning. The frequency and initial rate of growth/decay of the oscillations depend on both upstream and downstream conditions, with dimensionless bifurcate length and bypass fraction emerging as key downstream parameters. With a strong offshore sink, causing bypass in the bifurcate branches, we find that bifurcation dynamics become "frozen"; that is, the bifurcation settles on a permanent discharge ratio. In contrast, under depositional conditions, we identify three dynamical regimes: symmetric; soft avulsion, where both branches remain open but the dominant branch switches; and full avulsion. Finally, we show that differential subsidence alters these regimes, with the difference in average sediment supply to each branch exactly compensating for the difference in accommodation generation. Additionally, the model predicts that bifurcations with shorter branches are less asymmetric than bifurcations with longer branches, all else equal, providing a possible explanation for the difference between backwater length distributaries, which tend to be avulsive, and relatively stable mouth-bar-scale networks. We conclude that bifurcations are sensitive both quantitatively and qualitatively to downstream sinks.

  16. Investigation of wall mass transfer characteristics downstream of an orifice

    International Nuclear Information System (INIS)

    El-Gammal, M.; Ahmed, W.H.; Ching, C.Y.

    2012-01-01

    Highlights: ► Numerical simulations were performed for the mass transfer downstream of an orifice. ► The Low Reynolds Number K-ε turbulence model was used. ► The numerical results were in good agreement with existing experimental results. ► The maximum Sherwood number downstream of the orifice was significantly affected by the Reynolds number. ► The Sherwood number profile was well correlated with the turbulence kinetic energy profile close to the wall. - Abstract: Numerical simulations were performed to determine the effect of Reynolds number and orifice to pipe diameter ratio (d o /d) on the wall mass transfer rate downstream of an orifice. The simulations were performed for d o /d of 0.475 for Reynolds number up to 70,000. The effect of d o /d was determined by performing simulations at a Reynolds number of 70,000 for d o /d of 0.375, 0.475 and 0.575. The momentum and mass transport equations were solved using the Low Reynolds Number (LRN) K-ε turbulence model. The Sherwood number (Sh) profile downstream of the orifice was in relatively good agreement with existing experimental results. The Sh increases sharply downstream of the orifice, reaching a maximum within 1–2 diameters downstream of the orifice, before relaxing back to the fully developed pipe flow value. The Sh number well downstream of the orifice was in good agreement with results for fully developed pipe flow estimated from the correlation of . The peak Sh numbers from the simulations were higher than that predicted from and .

  17. Radon depth migration

    International Nuclear Information System (INIS)

    Hildebrand, S.T.; Carroll, R.J.

    1993-01-01

    A depth migration method is presented that used Radon-transformed common-source seismograms as input. It is shown that the Radon depth migration method can be extended to spatially varying velocity depth models by using asymptotic ray theory (ART) to construct wavefield continuation operators. These operators downward continue an incident receiver-array plane wave and an assumed point-source wavefield into the subsurface. The migration velocity model is constrain to have longer characteristic wavelengths than the dominant source wavelength such that the ART approximations for the continuation operators are valid. This method is used successfully to migrate two synthetic data examples: (1) a point diffractor, and (2) a dipping layer and syncline interface model. It is shown that the Radon migration method has a computational advantage over the standard Kirchhoff migration method in that fewer rays are computed in a main memory implementation

  18. Migration into art

    DEFF Research Database (Denmark)

    Petersen, Anne Ring

    This book addresses a topic of increasing importance to artists, art historians and scholars of cultural studies, migration studies and international relations: migration as a profoundly transforming force that has remodelled artistic and art institutional practices across the world. It explores...... contemporary art's critical engagement with migration and globalisation as a key source for improving our understanding of how these processes transform identities, cultures, institutions and geopolitics. The author explores three interwoven issues of enduring interest: identity and belonging, institutional...

  19. Regional Redistribution and Migration

    DEFF Research Database (Denmark)

    Manasse, Paolo; Schultz, Christian

    We study a model with free migration between a rich and a poor region. Since there is congestion, the rich region has an incentive to give the poor region a transfer in order to reduce immigration. Faced with free migration, the rich region voluntarily chooses a transfer, which turns out...... to be equal to that a social planner would choose. Provided migration occurs in equilibrium, this conclusion holds even in the presence of moderate mobility costs. However, large migration costs will lead to suboptimal transfers in the market solution...

  20. Protein kinase Cepsilon is important for migration of neuroblastoma cells

    International Nuclear Information System (INIS)

    Stensman, Helena; Larsson, Christer

    2008-01-01

    Migration is important for the metastatic capacity and thus for the malignancy of cancer cells. There is limited knowledge on regulatory factors that promote the migration of neuroblastoma cells. This study investigates the hypothesis that protein kinase C (PKC) isoforms regulate neuroblastoma cell motility. PKC isoforms were downregulated with siRNA or modulated with activators and inhibitors. Migration was analyzed with scratch and transwell assays. Protein phosphorylation and expression levels were measured with Western blot. Stimulation with 12-O-tetradecanoylphorbol-13-acetate (TPA) induced migration of SK-N-BE(2)C neuroblastoma cells. Treatment with the general protein kinase C (PKC) inhibitor GF109203X and the inhibitor of classical isoforms Gö6976 inhibited migration while an inhibitor of PKCβ isoforms did not have an effect. Downregulation of PKCε, but not of PKCα or PKCδ, with siRNA led to a suppression of both basal and TPA-stimulated migration. Experiments using PD98059 and LY294002, inhibitors of the Erk and phosphatidylinositol 3-kinase (PI3K) pathways, respectively, showed that PI3K is not necessary for TPA-induced migration. The Erk pathway might be involved in TPA-induced migration but not in migration driven by PKCε. TPA induced phosphorylation of the PKC substrate myristoylated alanine-rich C kinase substrate (MARCKS) which was suppressed by the PKC inhibitors. Treatment with siRNA oligonucleotides against different PKC isoforms before stimulation with TPA did not influence the phosphorylation of MARCKS. PKCε is important for migration of SK-N-BE(2)C neuroblastoma cells. Neither the Erk pathway nor MARCKS are critical downstream targets of PKCε but they may be involved in TPA-mediated migration

  1. Mortality of zebra mussel, Dreissena polymorpha, veligers during downstream transport

    Science.gov (United States)

    Horvath, T.G.; Lamberti, G.A.

    1999-01-01

    1. Streams flowing from lakes which contain zebra mussels, Dreissena polymorpha, provide apparently suitable habitats for mussel colonization and downstream range expansion, yet most such streams contain few adult mussels. We postulated that mussel veligers experience high mortality during dispersal via downstream transport. They tested this hypothesis in Christiana Creek, a lake-outlet stream in south-western Michigan, U.S.A., in which adult mussel density declined exponentially with distance downstream. 2. A staining technique using neutral red was developed and tested to distinguish quickly live and dead veligers. Live and dead veligers were distinguishable after an exposure of fresh samples to 13.3 mg L-1 of neutral red for 3 h. 3. Neutral red was used to determine the proportion of live veligers in samples taken longitudinally along Christiana Creek. The proportion of live veligers (mean ?? SE) declined from 90 ?? 3% at the lake outlet to 40 ?? 8% 18 km downstream. 4. Veligers appear to be highly susceptible to damage by physical forces (e.g. shear), and therefore, mortality in turbulent streams could be an important mechanism limiting zebra mussel dispersal to downstream reaches. Predictions of zebra mussel spread and population growth should consider lake-stream linkages and high mortality in running waters.

  2. Downstream Yangtze River levels impacted by Three Gorges Dam

    International Nuclear Information System (INIS)

    Wang, Jida; Sheng, Yongwei; Gleason, Colin J; Wada, Yoshihide

    2013-01-01

    Changes in the Yangtze River level induced by large-scale human water regulation have profound implications on the inundation dynamics of surrounding lakes/wetlands and the integrity of related ecosystems. Using in situ measurements and hydrological simulation, this study reveals an altered Yangtze level regime downstream from the Three Gorges Dam (TGD) to the Yangtze estuary in the East China Sea as a combined result of (i) TGD’s flow regulation and (ii) Yangtze channel erosion due to reduced sediment load. During the average annual cycle of TGD’s regular flow control in 2009–2012, downstream Yangtze level variations were estimated to have been reduced by 3.9–13.5% at 15 studied gauging stations, manifested as evident level decrease in fall and increase in winter and spring. The impacts on Yangtze levels generally diminished in a longitudinal direction from the TGD to the estuary, with a total time lag of ∼9–12 days. Chronic Yangtze channel erosion since the TGD closure has lowered water levels in relation to flows at most downstream stations, which in turn counteracts the anticipated level increase by nearly or over 50% in winter and spring while reinforcing the anticipated level decrease by over 20% in fall. Continuous downstream channel erosion in the near future may further counteract the benefit of increased Yangtze levels during TGD’s water supplement in winter and accelerate the receding of inundation areas/levels of downstream lakes in fall. (letter)

  3. Critical effects of downstream boundary conditions on vortex breakdown

    Science.gov (United States)

    Kandil, Osama; Kandil, Hamdy A.; Liu, C. H.

    1992-01-01

    The unsteady, compressible, full Navier-Stokes (NS) equations are used to study the critical effects of the downstream boundary conditions on the supersonic vortex breakdown. The present study is applied to two supersonic vortex breakdown cases. In the first case, quasi-axisymmetric supersonic swirling flow is considered in a configured circular duct, and in the second case, quasi-axisymmetric supersonic swirling jet, that is issued from a nozzle into a supersonic jet of lower Mach number, is considered. For the configured duct flow, four different types of downstream boundary conditions are used, and for the swirling jet flow from the nozzle, two types of downstream boundary conditions are used. The solutions are time accurate which are obtained using an implicit, upwind, flux-difference splitting, finite-volume scheme.

  4. ApoER2 Controls Not Only Neuronal Migration in the Intermediate Zone But Also Termination of Migration in the Developing Cerebral Cortex.

    Science.gov (United States)

    Hirota, Yuki; Kubo, Ken-Ichiro; Fujino, Takahiro; Yamamoto, Tokuo T; Nakajima, Kazunori

    2018-01-01

    Neuronal migration contributes to the establishment of mammalian brain. The extracellular protein Reelin sends signals to various downstream molecules by binding to its receptors, the apolipoprotein E receptor 2 (ApoER2) and very low-density lipoprotein receptor and exerts essential roles in the neuronal migration and formation of the layered neocortex. However, the cellular and molecular functions of Reelin signaling in the cortical development are not yet fully understood. Here, to gain insight into the role of Reelin signaling during cortical development, we examined the migratory behavior of Apoer2-deficient neurons in the developing brain. Stage-specific labeling of newborn neurons revealed that the neurons ectopically invaded the marginal zone (MZ) and that neuronal migration of both early- and late-born neurons was disrupted in the intermediate zone (IZ) in the Apoer2 KO mice. Rescue experiments showed that ApoER2 functions both in cell-autonomous and noncell-autonomous manners, that Rap1, integrin, and Akt are involved in the termination of migration beneath the MZ, and that Akt also controls neuronal migration in the IZ downstream of ApoER2. These data indicate that ApoER2 controls multiple processes in neuronal migration, including the early stage of radial migration and termination of migration beneath the MZ in the developing neocortex. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  5. Ion energy characteristics downstream of a high power helicon

    International Nuclear Information System (INIS)

    Prager, James; Winglee, Robert; Ziemba, Tim; Roberson, B Race; Quetin, Gregory

    2008-01-01

    The High Power Helicon eXperiment operates at higher powers (37 kW) and lower background neutral pressure than other helicon experiments. The ion velocity distribution function (IVDF) has been measured at multiple locations downstream of the helicon source and a mach 3-6 flowing plasma was observed. The helicon antenna has a direct effect in accelerating the plasma downstream of the source. Also, the IVDF is affected by the cloud of neutrals from the initial gas puff, which keeps the plasma speed low at early times near the source.

  6. Ion energy characteristics downstream of a high power helicon

    Energy Technology Data Exchange (ETDEWEB)

    Prager, James; Winglee, Robert; Ziemba, Tim; Roberson, B Race; Quetin, Gregory [University of Washington, Johnson Hall 070, Box 351310, 4000 15th Avenue NE, Seattle, WA 98195-1310 (United States)], E-mail: jprager@u.washington.edu

    2008-05-01

    The High Power Helicon eXperiment operates at higher powers (37 kW) and lower background neutral pressure than other helicon experiments. The ion velocity distribution function (IVDF) has been measured at multiple locations downstream of the helicon source and a mach 3-6 flowing plasma was observed. The helicon antenna has a direct effect in accelerating the plasma downstream of the source. Also, the IVDF is affected by the cloud of neutrals from the initial gas puff, which keeps the plasma speed low at early times near the source.

  7. Downstream Processability of Crystal Habit-Modified Active Pharmaceutical Ingredient

    DEFF Research Database (Denmark)

    Pudasaini, Nawin; Upadhyay, Pratik Pankaj; Parker, Christian Richard

    2017-01-01

    Efficient downstream processing of active pharmaceutical ingredients (APIs) can depend strongly on their particulate properties, such as size and shape distributions. Especially in drug products with high API content, needle-like crystal habit of an API may show compromised flowability and tablet......Efficient downstream processing of active pharmaceutical ingredients (APIs) can depend strongly on their particulate properties, such as size and shape distributions. Especially in drug products with high API content, needle-like crystal habit of an API may show compromised flowability...

  8. Samtidskunst og migration

    DEFF Research Database (Denmark)

    Petersen, Anne Ring

    2010-01-01

    "Samtidskunst og migration. En oversigt over faglitteraturen" er en forskningsoversigt der gør status over hvad der hidtil er skrevet inden for det kunsthistoriske område om vor tids billedkunst og migration som politisk, socialt og kulturelt fænomen, primært i forbindelse med immigration til...

  9. The Great Migration.

    Science.gov (United States)

    Trotter, Joe William, Jr.

    2002-01-01

    Describes the migration of African Americans in the United States and the reasons why African Americans migrated from the south. Focuses on issues, such as the effect of World War I, the opportunities offered in the north, and the emergence of a black industrial working class. (CMK)

  10. Migrating Art History

    DEFF Research Database (Denmark)

    Ørum, Tania

    2012-01-01

    Review of Hiroko Ikegami, The Great Migrator. Robert Rauschenberg and the Global Rise of American Art. Cambridge Mass., The MIT Press, 2010. 277 pages. ISBN 978-0-262-01425-0.......Review of Hiroko Ikegami, The Great Migrator. Robert Rauschenberg and the Global Rise of American Art. Cambridge Mass., The MIT Press, 2010. 277 pages. ISBN 978-0-262-01425-0....

  11. College Student Migration.

    Science.gov (United States)

    Fenske, Robert H.; And Others

    This study examines the background characteristics of two large national samples of first-time enrolled freshmen who (a) attended college within their state of residence but away from their home community, (b) migrated to a college in an adjacent state, (c) migrated to a college in a distant state, and (d) attended college in their home community.…

  12. Migration, klima og sundhed

    DEFF Research Database (Denmark)

    Tellier, Siri; Carballo, Manuel

    2009-01-01

    Many tentative connections have been postulated between migration and climate. This article points to rural-urban migration, particularly into low elevation urban slums prone to flooding as an issue needing urgent attention by health professionals. It also notes the no-man's land in which environ...

  13. Migration in Burkina Faso

    NARCIS (Netherlands)

    Wouterse, F.S.

    2007-01-01

    Migration plays an important role in development and as a strategy for poverty reduction. A recent World Bank investigation finds a significant positive relationship between international migration and poverty reduction at the country level (Adams and Page 2003). Burkina Faso, whose conditions for

  14. Migration, Narration, Identity

    DEFF Research Database (Denmark)

    Leese, Peter

    (co-editor with Carly McLaughlin and Wladyslaw Witalisz) This book presents articles resulting from joint research on the representations of migration conducted in connection with the Erasmus Intensive Programme entitled «Migration and Narration» taught to groups of international students over...

  15. The Globalisation of migration

    Directory of Open Access Journals (Sweden)

    Milan Mesić

    2002-04-01

    Full Text Available The paper demonstrates that contemporary international migration is a constitutive part of the globalisation process. After defining the concepts of globalisation and the globalisation of migration, the author discusses six key themes, linking globalisation and international migration (“global cities”, the scale of migration; diversification of migration flows; globalisation of science and education; international migration and citizenship; emigrant communities and new identities. First, in accordance with Saskia Sassen’s analysis, the author rejects the wide-spread notion that unqualified migrants have lost an (important role in »global cities«, i.e. in the centres of the new (global economy. Namely, the post-modern service sector cannot function without the support of a wide range of auxiliary unqualified workers. Second, a critical comparison with traditional overseas mass migration to the USA at the turn of the 19th and 20th centuries indicates that present international migration is, perhaps, less extensive – however it is important to take into consideration various limitations that previously did not exist, and thus the present migration potential is in really greater. Third, globalisation is more evident in a diversification of the forms of migration: the source area of migrants to the New World and Europe has expanded to include new regions in the world; new immigration areas have arisen (the Middle East, new industrial countries of the Far East, South Europe; intra-regional migration has intensified. Forth, globalisation is linked to an increased migration of experts and the pessimistic notion of a brain drain has been replaced by the optimistic idea of a brain gain. Fifth, contemporary international migration has been associated with a crisis of the national model of citizenship. Sixth, the interlinking of (migrant cultural communities regardless of distance and the physical proximity of cultural centres (the

  16. Malaysia and forced migration

    Directory of Open Access Journals (Sweden)

    Arzura Idris

    2012-06-01

    Full Text Available This paper analyzes the phenomenon of “forced migration” in Malaysia. It examines the nature of forced migration, the challenges faced by Malaysia, the policy responses and their impact on the country and upon the forced migrants. It considers forced migration as an event hosting multifaceted issues related and relevant to forced migrants and suggests that Malaysia has been preoccupied with the issue of forced migration movements. This is largely seen in various responses invoked from Malaysia due to “south-south forced migration movements.” These responses are, however, inadequate in terms of commitment to the international refugee regime. While Malaysia did respond to economic and migration challenges, the paper asserts that such efforts are futile if she ignores issues critical to forced migrants.

  17. Exploration of upstream and downstream process for microwave assisted sustainable biodiesel production from microalgae Chlorella vulgaris.

    Science.gov (United States)

    Sharma, Amit Kumar; Sahoo, Pradeepta Kumar; Singhal, Shailey; Joshi, Girdhar

    2016-09-01

    The present study explores the integrated approach for the sustainable production of biodiesel from Chlorella vulgaris microalgae. The microalgae were cultivated in 10m(2) open raceway pond at semi-continuous mode with optimum volumetric and areal production of 28.105kg/L/y and 71.51t/h/y, respectively. Alum was used as flocculent for harvesting the microalgae and optimized at different pH. Lipid was extracted using chloroform: methanol (2:1) and having 12.39% of FFA. Effect of various reaction conditions such as effect of catalyst, methanol:lipid ratio, reaction temperature and time on biodiesel yields were studied under microwave irradiation; and 84.01% of biodiesel yield was obtained under optimized reaction conditions. A comparison was also made between the biodiesel productions under conventional heating and microwave irradiation. The synthesized biodiesel was characterized by (1)H NMR, (13)C NMR, FTIR and GC; however, fuel properties of biodiesel were also studied using specified test methods as per ASTM and EN standards. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Imaging for monitoring downstream processing of fermentation broths

    DEFF Research Database (Denmark)

    Moiseyenko, Rayisa; Baum, Andreas; Jørgensen, Thomas Martini

    In relation to downstream processing of a fermentation broth coagulation/flocculation is a typical pretreatment method for separating undesirable particles/impurities from the wanted product. In the coagulation process the negatively charged impurities are destabilized by adding of a clarifying...

  19. DENSITY FLUCTUATIONS UPSTREAM AND DOWNSTREAM OF INTERPLANETARY SHOCKS

    Energy Technology Data Exchange (ETDEWEB)

    Pitňa, A.; Šafránková, J.; Němeček, Z.; Goncharov, O.; Němec, F.; Přech, L. [Charles University, Faculty of Mathematics and Physics, V Holešovičkách 2, 180 00 Prague 8 (Czech Republic); Chen, C. H. K. [Department of Physics, Imperial College London, London SW7 2AZ (United Kingdom); Zastenker, G. N., E-mail: jana.safrankova@mff.cuni.cz [Space Research Institute of Russian Academy of Sciences, Moscow, Russia, Profsoyuznaya ul. 84/32, Moscow 117997 (Russian Federation)

    2016-03-01

    Interplanetary (IP) shocks as typical large-scale disturbances arising from processes such as stream–stream interactions or Interplanetary Coronal Mass Ejection (ICME) launching play a significant role in the energy redistribution, dissipation, particle heating, acceleration, etc. They can change the properties of the turbulent cascade on shorter scales. We focus on changes of the level and spectral properties of ion flux fluctuations upstream and downstream of fast forward oblique shocks. Although the fluctuation level increases by an order of magnitude across the shock, the spectral slope in the magnetohydrodynamic range is conserved. The frequency spectra upstream of IP shocks are the same as those in the solar wind (if not spoiled by foreshock waves). The spectral slopes downstream are roughly proportional to the corresponding slopes upstream, suggesting that the properties of the turbulent cascade are conserved across the shock; thus, the shock does not destroy the shape of the spectrum as turbulence passes through it. Frequency spectra downstream of IP shocks often exhibit “an exponential decay” in the ion kinetic range that was earlier reported at electron scales in the solar wind or at ion scales in the interstellar medium. We suggest that the exponential shape of ion flux spectra in this range is caused by stronger damping of the fluctuations in the downstream region.

  20. Extreme wave phenomena in down-stream running modulated waves

    NARCIS (Netherlands)

    Andonowati, A.; Karjanto, N.; van Groesen, Embrecht W.C.

    Modulational, Benjamin-Feir, instability is studied for the down-stream evolution of surface gravity waves. An explicit solution, the soliton on finite background, of the NLS equation in physical space is used to study various phenomena in detail. It is shown that for sufficiently long modulation

  1. Downstream processing of Isochrysis galbana: a step towards microalgal biorefinery

    NARCIS (Netherlands)

    Gilbert-López, B.; Mendiola, J.A.; Fontecha, J.; Broek, van den L.A.M.; Sijtsma, L.; Cifuentes, A.; Herrero, M.; Ibáñez, E.

    2015-01-01

    An algae-based biorefinery relies on the efficient use of algae biomass through its fractionation of several valuable/bioactive compounds that can be used in industry. If this biorefinery includes green platforms as downstream processing technologies able to fulfill the requirements of green

  2. Patents and Downstream Innovation Suppression - Facts or Fiction?

    DEFF Research Database (Denmark)

    Howells, John

    the value of Kitch's prospect theory of patents, a theory that the social value of patents is that they enable the efficient coordination of technological development.    I re-examine history and legal sources bearing on Merges and Nelson's illustrative cases and find no case to illustrate downstream...

  3. Downstream flow top width prediction in a river system | Choudhury ...

    African Journals Online (AJOL)

    ANFIS, ARIMA and Hybrid Multiple Inflows Muskingum models (HMIM) were applied to simulate and forecast downstream discharge and flow top widths in a river system. The ANFIS model works on a set of linguistic rules while the ARIMA model uses a set of past values to predict the next value in a time series. The HMIM ...

  4. The role of headwater streams in downstream water quality

    Science.gov (United States)

    Alexander, R.B.; Boyer, E.W.; Smith, R.A.; Schwarz, G.E.; Moore, R.B.

    2007-01-01

    Knowledge of headwater influences on the water-quality and flow conditions of downstream waters is essential to water-resource management at all governmental levels; this includes recent court decisions on the jurisdiction of the Federal Clean Water Act (CWA) over upland areas that contribute to larger downstream water bodies. We review current watershed research and use a water-quality model to investigate headwater influences on downstream receiving waters. Our evaluations demonstrate the intrinsic connections of headwaters to landscape processes and downstream waters through their influence on the supply, transport, and fate of water and solutes in watersheds. Hydrological processes in headwater catchments control the recharge of subsurface water stores, flow paths, and residence times of water throughout landscapes. The dynamic coupling of hydrological and biogeochemical processes in upland streams further controls the chemical form, timing, and longitudinal distances of solute transport to downstream waters. We apply the spatially explicit, mass-balance watershed model SPARROW to consider transport and transformations of water and nutrients throughout stream networks in the northeastern United States. We simulate fluxes of nitrogen, a primary nutrient that is a water-quality concern for acidification of streams and lakes and eutrophication of coastal waters, and refine the model structure to include literature observations of nitrogen removal in streams and lakes. We quantify nitrogen transport from headwaters to downstream navigable waters, where headwaters are defined within the model as first-order, perennial streams that include flow and nitrogen contributions from smaller, intermittent and ephemeral streams. We find that first-order headwaters contribute approximately 70% of the mean-annual water volume and 65% of the nitrogen flux in second-order streams. Their contributions to mean water volume and nitrogen flux decline only marginally to about 55% and

  5. Methylation of Hg downstream from the Bonanza Hg mine, Oregon

    Science.gov (United States)

    Gray, John E.; Hines, Mark E.; Krabbenhoft, David P.; Thoms, Bryn

    2012-01-01

    Speciation of Hg and conversion to methyl-Hg were evaluated in stream sediment, stream water, and aquatic snails collected downstream from the Bonanza Hg mine, Oregon. Total production from the Bonanza mine was >1360t of Hg, during mining from the late 1800s to 1960, ranking it as an intermediate sized Hg mine on an international scale. The primary objective of this study was to evaluate the distribution, transport, and methylation of Hg downstream from a Hg mine in a coastal temperate climatic zone. Data shown here for methyl-Hg, a neurotoxin hazardous to humans, are the first reported for sediment and water from this area. Stream sediment collected from Foster Creek flowing downstream from the Bonanza mine contained elevated Hg concentrations that ranged from 590 to 71,000ng/g, all of which (except the most distal sample) exceeded the probable effect concentration (PEC) of 1060ng/g, the Hg concentration above which harmful effects are likely to be observed in sediment-dwelling organisms. Concentrations of methyl-Hg in stream sediment collected from Foster Creek varied from 11 to 62ng/g and were highly elevated compared to regional baseline concentrations (0.11-0.82ng/g) established in this study. Methyl-Hg concentrations in stream sediment collected in this study showed a significant correlation with total organic C (TOC, R2=0.62), generally indicating increased methyl-Hg formation with increasing TOC in sediment. Isotopic-tracer methods indicated that several samples of Foster Creek sediment exhibited high rates of Hg-methylation. Concentrations of Hg in water collected downstream from the mine varied from 17 to 270ng/L and were also elevated compared to baselines, but all were below the 770ng/L Hg standard recommended by the USEPA to protect against chronic effects to aquatic wildlife. Concentrations of methyl-Hg in the water collected from Foster Creek ranged from 0.17 to 1.8ng/L, which were elevated compared to regional baseline sites upstream and downstream

  6. Migration and AIDS.

    Science.gov (United States)

    1998-01-01

    This article presents the perspectives of UNAIDS and the International Organization for Migration (IOM) on migration and HIV/AIDS. It identifies research and action priorities and policy issues, and describes the current situation in major regions of the world. Migration is a process. Movement is enhanced by air transport, rising international trade, deregulation of trade practices, and opening of borders. Movements are restricted by laws and statutes. Denial to freely circulate and obtain asylum is associated with vulnerability to HIV infections. A UNAIDS policy paper in 1997 and IOM policy guidelines in 1988 affirm that refugees and asylum seekers should not be targeted for special measures due to HIV/AIDS. There is an urgent need to provide primary health services for migrants, voluntary counseling and testing, and more favorable conditions. Research is needed on the role of migration in the spread of HIV, the extent of migration, availability of health services, and options for HIV prevention. Research must be action-oriented and focused on vulnerability to HIV and risk taking behavior. There is substantial mobility in West and Central Africa, economic migration in South Africa, and nonvoluntary migration in Angola. Sex workers in southeast Asia contribute to the spread. The breakup of the USSR led to population shifts. Migrants in Central America and Mexico move north to the US where HIV prevalence is higher.

  7. A novel virtual hub approach for multisource downstream service integration

    Science.gov (United States)

    Previtali, Mattia; Cuca, Branka; Barazzetti, Luigi

    2016-08-01

    A large development of downstream services is expected to be stimulated starting from earth observations (EO) datasets acquired by Copernicus satellites. An important challenge connected with the availability of downstream services is the possibility for their integration in order to create innovative applications with added values for users of different categories level. At the moment, the world of geo-information (GI) is extremely heterogeneous in terms of standards and formats used, thus preventing a facilitated access and integration of downstream services. Indeed, different users and data providers have also different requirements in terms of communication protocols and technology advancement. In recent years, many important programs and initiatives have tried to address this issue even on trans-regional and international level (e.g. INSPIRE Directive, GEOSS, Eye on Earth and SEIS). However, a lack of interoperability between systems and services still exists. In order to facilitate the interaction between different downstream services, a new architectural approach (developed within the European project ENERGIC OD) is proposed in this paper. The brokering-oriented architecture introduces a new mediation layer (the Virtual Hub) which works as an intermediary to bridge the gaps linked to interoperability issues. This intermediation layer de-couples the server and the client allowing a facilitated access to multiple downstream services and also Open Data provided by national and local SDIs. In particular, in this paper an application is presented integrating four services on the topic of agriculture: (i) the service given by Space4Agri (providing services based on MODIS and Landsat data); (ii) Gicarus Lab (providing sample services based on Landsat datasets) and (iii) FRESHMON (providing sample services for water quality) and services from a several regional SDIs.

  8. Labor migration in Asia.

    Science.gov (United States)

    Martin, P L

    1991-01-01

    "A recent conference sponsored by the United Nations Center for Regional Development (UNCRD) in Nagoya, Japan examined the growing importance of labor migration for four major Asian labor importers (Japan, Hong Kong, Malaysia, and Singapore) and five major labor exporters (Bangladesh, Korea, Pakistan, Philippines, and Thailand).... The conference concluded that international labor migration would increase within Asia because the tight labor markets and rising wages which have stimulated Japanese investment in other Asian nations, for example, have not been sufficient to eliminate migration push and pull forces...." excerpt

  9. Neuronal Migration Disorders

    Science.gov (United States)

    ... Understanding Sleep The Life and Death of a Neuron Genes At Work In The Brain Order Publications ... birth defects caused by the abnormal migration of neurons in the developing brain and nervous system. In ...

  10. Migration og etnicitet

    DEFF Research Database (Denmark)

    Christiansen, Connie Carøe

    2004-01-01

    Migration og etnicitet er aktuelle og forbundne fænomener, idet migration øger berøringsfladerne mellem befolkningsgrupper. Etniciteter formes i takt med at grænser drages imellem disse grupper. Imod moderniserings-teoriernes forventning forsvandt etnicitet ikke som en traditionel eller oprindelig...... måde at skabe tilhørsforhold på; globalt set fremstår vor tid istedet som en "migrationens tidsalder", der tilsyneladende også er en tidsalder, hvor kulturelle særtræk, i form af etnicitet, udgør vigtige linjer, hvorefter grupper skilller sig ud fra hinanden. Både migration og etnicitet bringer fokus...... den finder sted i modtagerlandet, men nyere perspektiver på migration, som begreber om medborgerskab, transnationalisme og diaspora er eksponenter for, søger udover den nationalstatslige ramme og inddrager konsekvenserne af migrationen for afsenderlande....

  11. The impact of small irrigation diversion dams on the recent migration rates of steelhead and redband trout (Oncorhynchus mykiss)

    Science.gov (United States)

    Weigel, Dana E.; Connolly, Patrick J.; Powell, Madison S.

    2013-01-01

    Barriers to migration are numerous in stream environments and can occur from anthropogenic activities (such as dams and culverts) or natural processes (such as log jams or dams constructed by beaver (Castor canadensis)). Identification of barriers can be difficult when obstructions are temporary or incomplete providing passage periodically. We examine the effect of several small irrigation diversion dams on the recent migration rates of steelhead (Oncorhynchus mykiss) in three tributaries to the Methow River, Washington. The three basins had different recent migration patterns: Beaver Creek did not have any recent migration between sites, Libby Creek had two-way migration between sites and Gold Creek had downstream migration between sites. Sites with migration were significantly different from sites without migration in distance, number of obstructions, obstruction height to depth ratio and maximum stream gradient. When comparing the sites without migration in Beaver Creek to the sites with migration in Libby and Gold creeks, the number of obstructions was the only significant variable. Multinomial logistic regression identified obstruction height to depth ratio and maximum stream gradient as the best fitting model to predict the level of migration among sites. Small irrigation diversion dams were limiting population interactions in Beaver Creek and collectively blocking steelhead migration into the stream. Variables related to stream resistance (gradient, obstruction number and obstruction height to depth ratio) were better predictors of recent migration rates than distance, and can provide important insight into migration and population demographic processes in lotic species.

  12. Experimental investigation of fish downstream passage and turbine related fish mortality at an innovative hydro power setup

    International Nuclear Information System (INIS)

    Geiger, Franz; Cuchet, Mathilde; Rutschmann, Peter

    2016-01-01

    The fish downstream passage of small fish at the innovative TUM hydro shaft power plant concept was investigated experimentally. The behavior of 1974 inserted individuals of brown trout, grayling, barbel, minnow and bullhead of 45 mm to 220 mm body length was observed in a fully functional test setup which included a 35 kW Kaplan turbine and a horizontal screen with 20 mm bar clearance. The 24 h tests were conducted under nature like conditions whereas the laboratory environment also enabled targeted hydraulic situations and modifications of the bypass during the test series. A recapture rate of the fish of 99% and a subsequent 96 h observation period yielded detailed information about the migration behavior and instant as well as long term mortality. The results reveal the actual passage distribution of small fish between bypass and turbine and the turbine related injury and mortality rates in dependency of fish species, fish length, turbine discharge and bypass arrangement. General trends as well as species specific particularities could be deduced. The work confirms the suitability of the employed experimental approach and the ecological potential of the investigated hydro power plant concept. The behavioral barrier effect of the screen on small fish and the necessary of appropriate downstream migration corridor were proved and quantified. (authors)

  13. Indonesia's migration transition.

    Science.gov (United States)

    Hugo, G

    1995-01-01

    This article describes population movements in Indonesia in the context of rapid and marked social and economic change. Foreign investment in Indonesia is increasing, and global mass media is available to many households. Agriculture is being commercialized, and structural shifts are occurring in the economy. Educational levels are increasing, and women's role and status are shifting. Population migration has increased over the decades, both short and long distance, permanent and temporary, legal and illegal, and migration to and between urban areas. This article focuses specifically on rural-to-urban migration and international migration. Population settlements are dense in the agriculturally rich inner areas of Java, Bali, and Madura. Although the rate of growth of the gross domestic product was 6.8% annually during 1969-94, the World Bank ranked Indonesia as a low-income economy in 1992 because of the large population size. Income per capita is US $670. Indonesia is becoming a large exporter of labor to the Middle East, particularly women. The predominance of women as overseas contract workers is changing women's role and status in the family and is controversial due to the cases of mistreatment. Malaysia's high economic growth rate of over 8% per year means an additional 1.3 million foreign workers and technicians are needed. During the 1980s urban growth increased at a very rapid rate. Urban growth tended to occur along corridors and major transportation routes around urban areas. It is posited that most of the urban growth is due to rural-to-urban migration. Data limitations prevent an exact determination of the extent of rural-to-urban migration. More women are estimated to be involved in movements to cities during the 1980s compared to the 1970s. Recruiters and middlemen have played an important role in rural-to-urban migration and international migration.

  14. Repeat migration and disappointment.

    Science.gov (United States)

    Grant, E K; Vanderkamp, J

    1986-01-01

    This article investigates the determinants of repeat migration among the 44 regions of Canada, using information from a large micro-database which spans the period 1968 to 1971. The explanation of repeat migration probabilities is a difficult task, and this attempt is only partly successful. May of the explanatory variables are not significant, and the overall explanatory power of the equations is not high. In the area of personal characteristics, the variables related to age, sex, and marital status are generally significant and with expected signs. The distance variable has a strongly positive effect on onward move probabilities. Variables related to prior migration experience have an important impact that differs between return and onward probabilities. In particular, the occurrence of prior moves has a striking effect on the probability of onward migration. The variable representing disappointment, or relative success of the initial move, plays a significant role in explaining repeat migration probabilities. The disappointment variable represents the ratio of actural versus expected wage income in the year after the initial move, and its effect on both repeat migration probabilities is always negative and almost always highly significant. The repeat probabilities diminish after a year's stay in the destination region, but disappointment in the most recent year still has a bearing on the delayed repeat probabilities. While the quantitative impact of the disappointment variable is not large, it is difficult to draw comparisons since similar estimates are not available elsewhere.

  15. Dead zone area at the downstream flow of barrages

    Directory of Open Access Journals (Sweden)

    Mohamed F. Sauida

    2016-12-01

    Full Text Available Flow separation is a natural phenomenon encountered at some cases downstream of barrages. The main flow is divided into current and dead zone flows. The percentage area of dead zone flow must be taken into consideration downstream of barrages, due to its negative effect on flow characteristics. Experimental studies were conducted in the Hydraulic Research Institute (HRI, on a physical regulator model with five vents. Theoretically the separation zone is described as a part of an ellipse which is practically verified by plotting velocity vectors. The results show that the percentage area of dead zone to the area through length of separation depends mainly on the expansion ratio [channel width to width of opened vents], with maximum value of 81% for operated side gates. A statistical analysis was derived, to predict the percentage area of dead zone flow to the area through length of separation.

  16. Upstream-downstream cooperation approach in Guanting Reservoir watershed.

    Science.gov (United States)

    Yang, Zhi-Feng; Zhang, Wen-Guo

    2005-01-01

    A case study is introduced and discussed concerning water dispute of misuse and pollution between up- and down-stream parts. The relations between water usage and local industrial structures are analyzed. Results show it is important to change industrial structures of the target region along with controlling water pollution by technical and engineering methods. Three manners of upstream-downstream cooperation are presented and discussed based on the actual conditions of Guangting Reservoir watershed. Two typical scenarios are supposed and studied along with the local plan on water resources development. The best solution for this cooperation presents a good way to help the upstream developing in a new pattern of eco-economy.

  17. OGJ group weathered tough times upstream and downstream in 1991

    International Nuclear Information System (INIS)

    Biggs, J.B.; Price, R.B.

    1992-01-01

    With an upstream sector hit by low oil and gas prices and downstream operations squeezed by weak petroleum demand, 1991, was a tough year for the group of 22 major integrated U.S. companies Oil and Gas Journal tracks. This paper reports that the brief respite caused by the oil price spike in second half 1990 ended abruptly early in first half 1991, and it turned into a year of buckling down for most companies. They shed non-core assets, implemented strategic restructuring moves, and reduced staff. Although low prices slowed overall drilling activity for the group, oil and gas production increased slightly, and most companies reported reserves gains. Recession in the U.S. and Europe depressed demand for the group's fined products enough to pinch downstream earnings even as buoyant Asia-Pacific demand helped jack up world product sales

  18. Downstream management practices of transnational companies in institutionally vulnerable countries

    DEFF Research Database (Denmark)

    Jørgensen, Michael Søgaard; Milanez, Bruno

    2017-01-01

    Analyses of social and environmental management in transnational product chains focus often upstream on suppliers in socially and institutionally vulnerable countries and these suppliers' hazardous processes. Furthermore focus is on transnational companies' responsibility when they source from...... such suppliers. On the contrary, not much focus has been on transnational companies' downstream export of hazardous products to vulnerable countries and the product use in those countries. The article uses pesticides as case of hazardous products and identifies mechanisms in the downstream social...... and environmental management of a Danish pesticide company in vulnerable countries and especially in Brazil. The identified mechanisms are: the transnational company's on-going interpretation of the regulatory and ethical obligations for development and use of its hazardous products in vulnerable countries, path...

  19. International Retailing Operations: Downstream Entry and Expansion via Franchising

    OpenAIRE

    Petersen, Bent; Welch, Lawrence S.

    1999-01-01

    In this article, the shift into international franchising from other forms of operation, rather than the typical home market franchising base is explored. The focus is international retail franchising, based on a study of the Danish clothing and footwear industry. In this study it was found that Danish companies were moving into international franchising as an outcome of a more general shift from upstream wholesaling and subcontracting activities to downstream involvement in retailing activit...

  20. Analysis of Petroleum Downstream Industry Potential in Riau Province

    Directory of Open Access Journals (Sweden)

    Tomi Erfando

    2017-06-01

    Full Text Available Petroleum downstream industry in Riau Province is still not optimal. The data shows that from 98,892,755 barrels lifting oil each year only 62,050,000 barrels could be processed in refinery unit II Dumai operated by PT Pertamina. There is a potential of 35-40% of downstream industry. Indonesian Government through The Ministry of Energy and Mineral Resources declared the construction of a mini refinery to boost oil processing output in the downstream sector. A feasibility study of development plan mini refinery is needed. The study includes production capacity analysis, product analysis, development & operational refinery  analysis and economic analysis. The results obtained by the mini refinery capacity is planned to process crude oil 6000 BOPD with the products produced are gasoline, kerosene, diesel and oil. Investment cost consist of is capital cost US $ 104419784 and operating cost US $ 13766734 each year with net profit earned US $ 12330063/year and rate of return from investment 11.63%

  1. Ontogenetic behavior and migration of Atlantic sturgeon, Acipenser oxyrinchus oxyrinchus, and shortnose sturgeon, A. brevirostrum, with notes on social behavior

    Science.gov (United States)

    Kynard, B.; Horgan, M.

    2002-01-01

    Ontogenetic behavior of Hudson River Atlantic sturgeon and Connecticut River shortnose sturgeon early life intervals were similar during laboratory observations. After hatching, free embryos were photonegative and sought cover. When embryos developed into larvae, fish left cover, were photopositive, and initiated downstream migration. Free embryos may remain at the spawning site instead of migrating downstream because the risk of predation at spawning sites is low. The two species are sympatric, but not closely related, so the similarities in innate behaviors suggest common adaptations, not phylogenetlc relationship. Atlantic sturgeon migrated downstream for 12 days (peak, first 6 days), shortnose sturgeon migrated for 3 days, and year-0 juveniles of both species did not resume downstream migration. Short or long migrations of larvae may reflect different styles related to the total migratory distance from spawning sites to juvenile rearing areas. Atlantic sturgeon need to move a short distance to reach rearing areas and they had a long 1-step migration of 6-12 days. In contrast, shortnose sturgeon need to move a long distance to reach all rearing areas. This may be accomplished by a 2-step migration, of which the brief migration of larvae is only the first step. Early migrant Atlantic sturgeon were nocturnal, while late migrants were diurnal, and shortnose sturgeon were diurnal. These diel differences may also be adaptations for long (Atlantic sturgeon) or short (shortnose sturgeon) migrations. Cultured shortnose sturgeon, and possibly Atlantic sturgeon, have a dominance hierarchy with large fish dominant when competing for limited foraging space. Social behavior may be more important in the life history of wild sturgeons than is generally recognized.

  2. Managing migration: the Brazilian case

    OpenAIRE

    Eduardo L. G. Rios-Neto

    2005-01-01

    The objective of this paper is to present the Brazilian migration experience and its relationship with migration management. The article is divided into three parts. First, it reviews some basic facts regarding Brazilian immigration and emigration processes. Second, it focuses on some policy and legal issues related to migration. Finally, it addresses five issues regarding migration management in Brazil.

  3. A computational fluid dynamics modeling study of guide walls for downstream fish passage

    Science.gov (United States)

    Mulligan, Kevin; Towler, Brett; Haro, Alexander J.; Ahlfeld, David P.

    2017-01-01

    A partial-depth, impermeable guidance structure (or guide wall) for downstream fish passage is typically constructed as a series of panels attached to a floating boom and anchored across a water body (e.g. river channel, reservoir, or power canal). The downstream terminus of the wall is generally located nearby to a fish bypass structure. If guidance is successful, the fish will avoid entrainment in a dangerous intake structure (i.e. turbine intakes) while passing from the headpond to the tailwater of a hydroelectric facility through a safer passage route (i.e. the bypass). The goal of this study is to determine the combination of guide wall design parameters that will most likely increase the chance of surface-oriented fish being successfully guided to the bypass. To evaluate the flow field immediately upstream of a guide wall, a parameterized computational fluid dynamics model of an idealized power canal was constructed in © ANSYS Fluent v 14.5 (ANSYS Inc., 2012). The design parameters investigated were the angle and depth of the guide wall and the average approach velocity in the power canal. Results call attention to the importance of the downward to sweeping flow ratio and demonstrate how a change in guide wall depth and angle can affect this important hydraulic cue to out-migrating fish. The key findings indicate that a guide wall set at a small angle (15° is the minimum in this study) and deep enough such that sweeping flow dominant conditions prevail within the expected vertical distribution of fish approaching the structure will produce hydraulic conditions that are more likely to result in effective passage.

  4. Inhibition of radiation induced migration of human head and neck squamous cell carcinoma cells by blocking of EGF receptor pathways

    International Nuclear Information System (INIS)

    Pickhard, Anja C; Schlegel, Jürgen; Arnold, Wolfgang; Reiter, Rudolf; Margraf, Johanna; Knopf, Andreas; Stark, Thomas; Piontek, Guido; Beck, Carolin; Boulesteix, Anne-Laure; Scherer, Elias Q; Pigorsch, Steffi

    2011-01-01

    Recently it has been shown that radiation induces migration of glioma cells and facilitates a further spread of tumor cells locally and systemically. The aim of this study was to evaluate whether radiotherapy induces migration in head and neck squamous cell carcinoma (HNSCC). A further aim was to investigate the effects of blocking the epidermal growth factor receptor (EGFR) and its downstream pathways (Raf/MEK/ERK, PI3K/Akt) on tumor cell migration in vitro. Migration of tumor cells was assessed via a wound healing assay and proliferation by a MTT colorimeritric assay using 3 HNSCC cell lines (BHY, CAL-27, HN). The cells were treated with increasing doses of irradiation (2 Gy, 5 Gy, 8 Gy) in the presence or absence of EGF, EGFR-antagonist (AG1478) or inhibitors of the downstream pathways PI3K (LY294002), mTOR (rapamycin) and MEK1 (PD98059). Biochemical activation of EGFR and the downstream markers Akt and ERK were examined by Western blot analysis. In absence of stimulation or inhibition, increasing doses of irradiation induced a dose-dependent enhancement of migrating cells (p < 0.05 for the 3 HNSCC cell lines) and a decrease of cell proliferation (p < 0.05 for the 3 HNSCC cell lines). The inhibition of EGFR or the downstream pathways reduced cell migration significantly (almost all p < 0.05 for the 3 HNSCC cell lines). Stimulation of HNSCC cells with EGF caused a significant increase in migration (p < 0.05 for the 3 HNSCC cell lines). After irradiation alone a pronounced activation of EGFR was observed by Western blot analysis. Our results demonstrate that the EGFR is involved in radiation induced migration of HNSCC cells. Therefore EGFR or the downstream pathways might be a target for the treatment of HNSCC to improve the efficacy of radiotherapy

  5. RGMs : Structural Insights, Molecular Regulation, and Downstream Signaling

    NARCIS (Netherlands)

    Siebold, Christian; Yamashita, Toshihide; Monnier, Philippe P.; Mueller, Bernhard K.; Pasterkamp, R. Jeroen

    Although originally discovered as neuronal growth cone-collapsing factors, repulsive guidance molecules (RGMs) are now known as key players in many fundamental processes, such as cell migration, differentiation, iron homeostasis, and apoptosis, during the development and homeostasis of many tissues

  6. Headwater Stream Management Dichotomies: Local Amphibian Habitat vs. Downstream Fish Habitat

    Science.gov (United States)

    Jackson, C. R.

    2002-12-01

    Small headwater streams in mountainous areas of the Pacific Northwest often do not harbor fish populations because of low water depth and high gradients. Rather, these streams provide habitat for dense assemblages of stream-dwelling amphibians. A variety of management goals have been suggested for such streams such as encouraging large woody debris recruitment to assist in sediment trapping and valley floor formation, encouraging large woody debris recruitment to provide downstream wood when debris flows occur, providing continuous linear stream buffers within forest harvest areas to provide shade and bank stability, etc. A basic problem with analying the geomorphic or biotic benefits of any of these strategies is the lack of explicit management goals for such streams. Should managers strive to optimize downstream fish habitat, local amphibian habitat, or both? Through observational data and theoretical considerations, it will be shown that these biotic goals will lead to very different geomorphic management recommendations. For instance, woody debris greater than 60 cm diameter may assist in valley floor development, but it is likely to create subsurface channel flow of unknown value to amphibians. Trapping and retention of fine sediments within headwater streams may improve downstream spawning gravels, but degrades stream-dwelling amphibian habitat. In response to the need for descriptive information on habitat and channel morphology specific to small, non-fish-bearing streams in the Pacific Northwest, morphologies and wood frequencies in forty-two first- and second-order forested streams less than four meters wide were surveyed. Frequencies and size distributions of woody debris were compared between small streams and larger fish-bearing streams as well as between second-growth and virgin timber streams. Statistical models were developed to explore dominant factors affecting channel morphology and habitat. Findings suggest geomorphological relationships

  7. Prestack depth migration

    International Nuclear Information System (INIS)

    Postma, R.W.

    1991-01-01

    Two lines form the southern North Sea, with known velocity inhomogeneities in the overburden, have been pre-stack depth migrated. The pre-stack depth migrations are compared with conventional processing, one with severe distortions and one with subtle distortions on the conventionally processed sections. The line with subtle distortions is also compared with post-stack depth migration. The results on both lines were very successful. Both have already influenced drilling decisions, and have caused a modification of structural interpretation in the respective areas. Wells have been drilled on each of the lines, and well tops confirm the results. In fact, conventional processing led to incorrect locations for the wells, both of which were dry holes. The depth migrated sections indicate the incorrect placement, and on one line reveals a much better drilling location. This paper reports that even though processing costs are high for pre-stack depth migration, appropriate use can save millions of dollars in dry-hole expense

  8. Migration = cloning; aliasiing

    DEFF Research Database (Denmark)

    Hüttel, Hans; Kleist, Josva; Nestmann, Uwe

    1999-01-01

    In Obliq, a lexically scoped, distributed, object-oriented programming language, object migration was suggested as the creation of a copy of an object’s state at the target site, followed by turning the object itself into an alias, also called surrogate, for the remote copy. We consider the creat......In Obliq, a lexically scoped, distributed, object-oriented programming language, object migration was suggested as the creation of a copy of an object’s state at the target site, followed by turning the object itself into an alias, also called surrogate, for the remote copy. We consider...... the creation of object surrogates as an abstraction of the abovementioned style of migration. We introduce Øjeblik, a distribution-free subset of Obliq, and provide three different configuration-style semantics, which only differ in the respective aliasing model. We show that two of the semantics, one of which...... matches Obliq’s implementation, render migration unsafe, while our new proposal for a third semantics is provably safe. Our work suggests a straightforward repair of Obliq’s aliasing model such that it allows programs to safely migrate objects....

  9. Assistive Technology

    Science.gov (United States)

    ... Page Resize Text Printer Friendly Online Chat Assistive Technology Assistive technology (AT) is any service or tool that helps ... be difficult or impossible. For older adults, such technology may be a walker to improve mobility or ...

  10. En fornemmelse for migration

    DEFF Research Database (Denmark)

    Schütze, Laura Maria

    Afhandlingen undersøger, hvordan sted, museets rolle som aktør og religion er relevante for produktionen af migration på Immigrantmuseet (2012) og i Københavns Museums udstilling At blive københavner (2010). Afhandlingen er baseret på udstillingsanalyse samt interview med relevant museumsfagligt......, anvendes som virkemidler til at nuancere migration og distancere udstillingen fra den offentlige debat om indvandring. Afhandlingen peger på, at produktionen af den nyere danske historie på museum er præget af et fravær af religion. Det skyldes, at de museumsfaglige praksisser og traditioner afspejler en...... identiteter, som vi tager for givet: nationer, byer, kvinder - såvel som migration og religion. Afhandlingen argumenterer følgelig for, at museernes produktion af (materiel) religion er et særdeles relevant, men kun ringe udforsket, genstandsfelt for religionssociologien....

  11. Assisted Living

    Science.gov (United States)

    ... it, too. Back to top What is the Cost for Assisted Living? Although assisted living costs less than nursing home ... Primarily, older persons or their families pay the cost of assisted living. Some health and long-term care insurance policies ...

  12. What's driving migration?

    Science.gov (United States)

    Kane, H

    1995-01-01

    During the 1990s investment in prevention of international or internal migration declined, and crisis intervention increased. The budgets of the UN High Commissioner for Refugees and the UN Development Program remained about the same. The operating assumption is that war, persecution, famine, and environmental and social disintegration are inevitable. Future efforts should be directed to stabilizing populations through investment in sanitation, public health, preventive medicine, land tenure, environmental protection, and literacy. Forces pushing migration are likely to increase in the future. Forces include depletion of natural resources, income disparities, population pressure, and political disruption. The causes of migration are not constant. In the past, migration occurred during conquests, settlement, intermarriage, or religious conversion and was a collective movement. Current migration involves mass movement of individuals and the struggle to survive. There is new pressure to leave poor squatter settlements and the scarcities in land, water, and food. The slave trade between the 1500s and the 1800s linked continents, and only 2-3 million voluntarily crossed national borders. Involuntary migration began in the early 1800s when European feudal systems were in a decline, and people sought freedom. Official refugees, who satisfy the strict 1951 UN definition, increased from 15 million in 1980 to 23 million in 1990 but remained a small proportion of international migrants. Much of the mass movement occurs between developing countries. Migration to developed countries is accompanied by growing intolerance, which is misinformed. China practices a form of "population transfer" in Tibet in order to dilute Tibetan nationalism. Colonization of countries is a new less expensive form of control over territory. Eviction of minorities is another popular strategy in Iraq. Public works projects supported by foreign aid displace millions annually. War and civil conflicts

  13. Unix Application Migration Guide

    CERN Document Server

    Microsoft. Redmond

    2003-01-01

    Drawing on the experience of Microsoft consultants working in the field, as well as external organizations that have migrated from UNIX to Microsoft® Windows®, this guide offers practical, prescriptive guidance on the issues you are likely to face when porting existing UNIX applications to the Windows operating system environment. Senior IT decision makers, network managers, and operations managers will get real-world guidance and best practices on planning and implementation issues to understand the different methods through which migration or co-existence can be accomplished. Also detailing

  14. Migrating for a Profession

    DEFF Research Database (Denmark)

    Olwig, Karen Fog

    2015-01-01

    a strong sense of agency and self-empowerment. In the post-WWII period, numerous Caribbean women trained in nursing at British hospitals that have been described as marred by race and gender related inequality and associated forms of exploitation. Yet, the nurses interviewed about this training emphasised......Youths from the Global South migrating for further education often face various forms of discrimination. This Caribbean case study discusses how conditions in the home country can provide a foundation for educational migration that helps the migrants overcome such obstacles and even develop...... in which it enabled these Caribbean women to stake out a new life for themselves....

  15. Flow behavior of droplets downstream of the spacer

    International Nuclear Information System (INIS)

    Kodama, Eiichiro; Morishita, Kiyohide; Aritomi, Masanori; Yano, Takashi

    1998-01-01

    The fuel spacer, of which role is to maintain an appropriate rod-to-rod clearance, is one of the components of a Boiling Water Reactor (BWR) fuel rod bundles. The fuel spacer influences flow characteristics of the liquid film in fuel rod bundles, so that its geometry influences greatly thermal hydraulics such as critical power and pressure drop therein. The purpose of this study is to clarify the effect of the spacer geometry on the core flow split downstream of the spacer. Phase Doppler Anemometry (PDA) was used for their meausrement under the conditions of a small amount of droplets in mist flows. From the experimental results, the normalized droplet velocity profiles with a spacer were split by the spacer and were different between a wider and a narrower regions in the channel, however, they became uniform at the distance far 100mm from the spacer. In the case without a spacer, the velocity was monotonously increasing nearer the rod surface with going toward the center of the channel. In the case with a spacer, the velocity profile downstream of the spacer changed in the narrower region of the channel. This tendency became more remarkable with thickening the spacer and widening clearance between the spacer and the wall. In this paper, 'drift' velocity effect was applied for the spacer model, due to the gas flows were split by the spacer which is based on the momentum balance between the narrower and wider channels. This model was confirmed from the experimental results that the droplet flowed from a wider region to a narrower one. This drift effect appeared more strongly as the spacer became thicker and the clearance did narrower. The analytical results explained qualitatively the measured ones. It is clarified that the drift effect proposed in this work was a dominant factor on droplet deposition downstream of the spacer

  16. Climate change issue table : petroleum downstream sector industry foundation paper

    International Nuclear Information System (INIS)

    Crandall, G.R.; Kelly, S.J.; Kromm, R.B.; Prime, M.G.

    1999-01-01

    An analysis of the impact of the Kyoto Protocol on the Canadian downstream petroleum industry is presented. The downstream sector includes petroleum refining, plus all activities regarding distribution, marketing and retailing of petroleum products. In 1990, the carbon dioxide (CO 2 ) emissions resulting from the production and consumption of petroleum products were about 207 megatons which is about 45 per cent of total Canadian CO 2 emissions. This report includes the analysis of the Base Case and the Kyoto Case. The Base Case is premised on the implementation of fuel sulphur reductions to meet cleaner fuels requirements and an enhanced program of refinery efficiency initiatives. Under the Base Case assumptions the CO 2 emissions from refinery operations in 2010 would be about 3.4 below 1990 levels. The Kyoto Case was developed on the basis of reductions in Canadian petroleum product demand that would be sufficient to achieve a 6 per cent reduction in GHG emissions from the production and consumption of petroleum products relative to 1990 levels. The model demonstrates the dramatic economic impact of the Kyoto Case reductions on the Canadian downstream petroleum sector. Investment requirements for capital improvements to further distillate production and to further desulphurization are estimated at $ 1.5 billion between 2005 and 2015. The reduced volume of gasoline sales would be expected to result in rationalization of retail outlets, resulting in the closure of some 2,000 retail outlets with a combined loss of about 12,000 jobs. It is suggested that similar impact in other countries that are signatory to the Kyoto Protocol could result in the shift of refining, refining industry jobs and related economic benefits to countries which are not participants in the Kyoto Protocol. 14 tabs., 6 figs., 5 appendices

  17. Alfven waves and associated energetic ions downstream from Uranus

    International Nuclear Information System (INIS)

    Zhang, Ming; Belcher, J.W.; Richardson, J.D.; Smith, C.W.

    1991-01-01

    The authors report the observation of low-frequency waves in the solar wind downstream from Uranus. These waves are observed by the Voyager spacecraft for more than 2 weeks after the encounter with Uranus and are present during this period whenever the interplanetary magnetic field is oriented such that the field lines intersect the Uranian bow shock. The magnetic field and velocity components transverse to the background field are strongly correlated, consistent with the interpretation that these waves are Alfvenic and/or fast-mode waves. The waves have a spacecraft frame frequency of about 10 -3 Hz, and when first observed near the bow shock have an amplitude comparable to the background field. As the spacecraft moves farther from Uranus, the amplitude decays. The waves appear to propagate along the magnetic field lines outward from Uranus and are right-hand polarized. Theory suggests that these waves are generated in the upstream region by a resonant instability with a proton beam streaming along the magnetic field lines. The solar wind subsequently carries these waves downstream to the spacecraft location. These waves are associated with the presence of energetic (> 28 keV) ions observed by the low-energy charged particle instrument. These ions appear two days after the start of the wave activity and occur thereafter whenever the Alfven waves occur, increasing in intensity away from Uranus. The ions are argued to originate in the Uranian magnetosphere, but pitch-angle scattering in the upstream region is required to bring them downstream to the spacecraft location

  18. Flow diagnostics downstream of a tribladed rotor model

    DEFF Research Database (Denmark)

    Naumov, I. V.; Rahmanov, V. V.; Okulov, Valery

    2012-01-01

    This paper presents results of a study of vortex wake structures and measurements of instantaneous 3D velocity fields downstream of a triblade turbine model. Two operation modes of flow around the rotor with different tip speed ratios were tested. Initially the wake structures were visualized...... and subsequently quantitative data were recorded through velocity field restoration from particle tracks using a stereo PIV system.The study supplied flow diagnostics and recovered the instantaneous 3D velocity fields in the longitudinal cross section behind a tribladed rotor at different values of tip speed ratio...

  19. Recent Molecular Advances on Downstream Plant Responses to Abiotic Stress

    Directory of Open Access Journals (Sweden)

    Cláudia Regina Batista de Souza

    2012-07-01

    Full Text Available Abiotic stresses such as extremes of temperature and pH, high salinity and drought, comprise some of the major factors causing extensive losses to crop production worldwide. Understanding how plants respond and adapt at cellular and molecular levels to continuous environmental changes is a pre-requisite for the generation of resistant or tolerant plants to abiotic stresses. In this review we aimed to present the recent advances on mechanisms of downstream plant responses to abiotic stresses and the use of stress-related genes in the development of genetically engineered crops.

  20. 'Patents and Downstream Innovation Suppression - Fact or Fiction?'

    DEFF Research Database (Denmark)

    Howells, John

    Merges and Nelson have provided an empirically grounded argument that firms use pioneer patents of 'broad' scope to block downstream technological development (Merges and Nelson 1990). If this is a regular occurrence then, as they claim, they have faulted Kitch's 'prospect theory' of patents (Kitch...... 1977), a theory that is a version of the classic justification for the award of the exclusive right - that it should protect the incentive to develop property. Merges and Nelson insist that their thesis should be supported by empirical evidence and they turn to historical accounts as an important form...

  1. Migrating the Light

    DEFF Research Database (Denmark)

    Sørensen, Bent

    The migration of Blaga’s universalist, even centralist poems from Romanian of the first third of the 20th C. into American of the first fifth of the 21st C. illustrates the uses of Pierre Joris’s nomadic methods. My translations of Blaga read well for a teenage audience whose only exposure to lit...

  2. Describing migration spatial structure

    NARCIS (Netherlands)

    Rogers, A; Willekens, F; Little, J; Raymer, J

    The age structure of a population is a fundamental concept in demography and is generally depicted in the form of an age pyramid. The spatial structure of an interregional system of origin-destination-specific migration streams is, however, a notion lacking a widely accepted definition. We offer a

  3. Brain Migration Revisited

    Science.gov (United States)

    Vinokur, Annie

    2006-01-01

    The "brain drain/brain gain" debate has been going on for the past 40 years, with irresolvable theoretical disputes and unenforceable policy recommendations that economists commonly ascribe to the lack of reliable empirical data. The recent report of the World Bank, "International migration, remittances and the brain drain", documents the…

  4. Dispersal and migration

    Directory of Open Access Journals (Sweden)

    Schwarz, C.

    2004-06-01

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

  5. Migration and Africa

    DEFF Research Database (Denmark)

    Zoppi, Marco

    2014-01-01

    European powers imposed the nation-state on Africa through colonialism. But even after African independencies, mainstream discourses and government policies have amplified the idea that sedentariness and the state are the only acceptable mode of modernity. Migration is portrayed as a menace...

  6. Migration as Adventure

    DEFF Research Database (Denmark)

    Olwig, Karen Fog

    2018-01-01

    Narratives of adventure constitute a well-established convention of describing travel experiences, yet the significance of this narrative genre in individuals’ accounts of their migration and life abroad has been little investigated. Drawing on Simmel and Bakhtin, among others, this article...

  7. Digitizing migration heritage

    DEFF Research Database (Denmark)

    Marselis, Randi

    2011-01-01

    Museums are increasingly digitizing their collections and making them available to the public on-line. Creating such digital resources may become means for social inclusion. For museums that acknowledge migration history and cultures of ethnic minority groups as important subjects in multiethnic...

  8. The politicisation of migration

    NARCIS (Netherlands)

    van der Brug, W.; D' Amato, G.; Berkhout, J.; Ruedin, D.

    2015-01-01

    Why are migration policies sometimes heavily contested and high on the political agenda? And why do they, at other moments and in other countries, hardly lead to much public debate? The entrance and settlement of migrants in Western Europe has prompted various political reactions. In some countries

  9. Practical Data Migration

    CERN Document Server

    Morris, Johny

    2012-01-01

    This book is for executives and practitioners tasked with the movement of data from old systems to a new repository. It uses a series of steps guaranteed to get the reader from an empty new system to one that is working and backed by the user population. Using this proven methodology will vastly increase the chances of a successful migration.

  10. Migration pathways in soils

    International Nuclear Information System (INIS)

    Gronow, J.R.

    1986-01-01

    This study looked at diffusive migration through three types of deformation; the projectile pathways, hydraulic fractures of the sediments and faults, and was divided into three experimental areas: autoradiography, the determination of diffusion coefficients and electron microscopy of model projectile pathways in clay. For the autoradiography, unstressed samples were exposed to two separate isotopes, Pm-147 (a possible model for Am behaviour) and the poorly sorbed iodide-125. The results indicated that there was no enhanced migration through deformed kaolin samples nor through fractured Great Meteor East (GME) sediment, although some was evident through the projectile pathways in GME and possibly through the GME sheared samples. The scanning electron microscopy of projectile pathways in clay showed that emplacement of a projectile appeared to have no effect on the orientation of particles at distances greater than two projectile radii from the centre of a projectile pathway. It showed that the particles were not simply aligned with the direction of motion of the projectile but that, the closer to the surface of a particular pathway, the closer the particles lay to their original orientation. This finding was of interest from two points of view: i) the ease of migration of a pollutant along the pathway, and ii) possible mechanisms of hole closure. It was concluded that, provided that there is no advective migration, the transport of radionuclides through sediments containing these defects would not be significantly more rapid than in undeformed sediments. (author)

  11. International Migration of Couples

    DEFF Research Database (Denmark)

    Junge, Martin; Munk, Martin D.; Nikolka, Till

    2018-01-01

    Migrant self-selection is important to labor markets and public finances in both origin and destination countries. We develop a theoretical model regarding the migration of dual-earner couples and test it using population-wide administrative data from Denmark. Our model predicts that the probabil...

  12. PTHrP promotes malignancy of human oral cancer cell downstream of the EGFR signaling

    International Nuclear Information System (INIS)

    Yamada, Tamaki; Tsuda, Masumi; Ohba, Yusuke; Kawaguchi, Hideaki; Totsuka, Yasunori; Shindoh, Masanobu

    2008-01-01

    Parathyroid hormone-related protein (PTHrP) is detected in many aggressive tumors and involved in malignant conversion; however, the underlying mechanism remains obscure. Here, we identified PTHrP as a mediator of epidermal growth factor receptor (EGFR) signaling to promote the malignancies of oral cancers. PTHrP mRNA was abundantly expressed in most of the quiescent oral cancer cells, and was significantly upregulated by EGF stimulation via ERK and p38 MAPK. PTHrP silencing by RNA interference, as well as EGFR inhibitor AG1478 treatment, significantly suppressed cell proliferation, migration, and invasiveness. Furthermore, combined treatment of AG1478 and PTHrP knockdown achieved synergistic inhibition of malignant phenotypes. Recombinant PTHrP substantially promoted cell motility, and rescued the inhibition by PTHrP knockdown, suggesting the paracrine/autocrine function of PTHrP. These data indicate that PTHrP contributes to the malignancy of oral cancers downstream of EGFR signaling, and may thus provide a therapeutic target for oral cancer

  13. Monitoring of downstream salmon and steelhead at federal hydroelectric facilities

    International Nuclear Information System (INIS)

    Hawkes, L.A.; Martinson, R.D.; Absolon, R.F.

    1993-05-01

    The seaward migration of salmonid smolts was monitored by the National marine Fisheries Service (NMFS) at two sites on the Columbia River in 1992. The NMFS Smolt Monitoring Project is part of a larger Smolt Monitoring Program to index Columbia Basin juvenile salmonied stocks. It is coordinated by the Fish Passage Center (FPC) for the Columbia Basin Fish and Wildlife Agencies and Tribes. Its purpose is to facilitate fish passage through reservoirs and at dams by providing FPC with timely smolt migration data used for flow and spill management. Data is also used for travel time, migration timing and relative run size magnitude analysis. This program is carried out under the auspices of the Northwest Power Planning Council Fish and Wildlife Program and is funded by the Bonneville Power Administration (BPA). Sampling sites were John Day and Bonneville Dams under the 1992 Smolt Monitoring Program. All pertinent fish capture, condition, brand recovery, and flow data, were reported daily to FPC. These data were incorporated into the FPC's Fish Passage Data System (FPDS)

  14. Evaluation of Intracellular Signaling Downstream Chimeric Antigen Receptors.

    Directory of Open Access Journals (Sweden)

    Hannah Karlsson

    Full Text Available CD19-targeting CAR T cells have shown potency in clinical trials targeting B cell leukemia. Although mainly second generation (2G CARs carrying CD28 or 4-1BB have been investigated in patients, preclinical studies suggest that third generation (3G CARs with both CD28 and 4-1BB have enhanced capacity. However, little is known about the intracellular signaling pathways downstream of CARs. In the present work, we have analyzed the signaling capacity post antigen stimulation in both 2G and 3G CARs. 3G CAR T cells expanded better than 2G CAR T cells upon repeated stimulation with IL-2 and autologous B cells. An antigen-driven accumulation of CAR+ cells was evident post antigen stimulation. The cytotoxicity of both 2G and 3G CAR T cells was maintained by repeated stimulation. The phosphorylation status of intracellular signaling proteins post antigen stimulation showed that 3G CAR T cells had a higher activation status than 2G. Several proteins involved in signaling downstream the TCR were activated, as were proteins involved in the cell cycle, cell adhesion and exocytosis. In conclusion, 3G CAR T cells had a higher degree of intracellular signaling activity than 2G CARs which may explain the increased proliferative capacity seen in 3G CAR T cells. The study also indicates that there may be other signaling pathways to consider when designing or evaluating new generations of CARs.

  15. Tidal Influence on Water Quality of Kapuas Kecil River Downstream

    Science.gov (United States)

    Purnaini, Rizki; Sudarmadji; Purwono, Suryo

    2018-02-01

    The Kapuas Kecil River is strongly influenced by tidal, in the dry season the intrusion of surface water is often a problem for the WTP because it causes the change of raw water quality to be processed. The purpose of this study was to examine the effect of sea tides on water quality of the Kapuas Kecil River. The study was conducted in Kapuas River downstream along ± 30 km from the upper boundary to the estuary. Water sampling is carried out during the dry and rainy season, when the tidal conditions at 7 (seven) locations of the monitoring station. Descriptive analysis methods and regression-correlation statistics are used to determine the effect of tides on water quality in Kapuas River downstream. In general, the water quality of the Kapuas Kecil River has exceeded the criteria of first class water quality, ie water that can be used for drinking water. The status of water quality of the Kapuas Kecil River based on the pollution index calculation shows the condition of the river is "mild to medium pollutants". The result of multiple linear regression analysis got the value of coefficient of determination (adjusted R square) = 0,760, which in whole show that independent variable (tidal and distance) influence to dependent variable (value of TDS) equal to 76%.

  16. Turbulence downstream of subcoronary stentless and stented aortic valves.

    Science.gov (United States)

    Funder, Jonas Amstrup; Frost, Markus Winther; Wierup, Per; Klaaborg, Kaj-Erik; Hjortdal, Vibeke; Nygaard, Hans; Hasenkam, J Michael

    2011-08-11

    Regions of turbulence downstream of bioprosthetic heart valves may cause damage to blood components, vessel wall as well as to aortic valve leaflets. Stentless aortic heart valves are known to posses several hemodynamic benefits such as larger effective orifice areas, lower aortic transvalvular pressure difference and faster left ventricular mass regression compared with their stented counterpart. Whether this is reflected by diminished turbulence formation, remains to be shown. We implanted either stented pericardial valve prostheses (Mitroflow), stentless valve prostheses (Solo or Toronto SPV) in pigs or they preserved their native valves. Following surgery, blood velocity was measured in the cross sectional area downstream of the valves using 10MHz ultrasonic probes connected to a dedicated pulsed Doppler equipment. As a measure of turbulence, Reynolds normal stress (RNS) was calculated at two different blood pressures (baseline and 50% increase). We found no difference in maximum RNS measurements between any of the investigated valve groups. The native valve had significantly lower mean RNS values than the Mitroflow (p=0.004), Toronto SPV (p=0.008) and Solo valve (p=0.02). There were no statistically significant differences between the artificial valve groups (p=0.3). The mean RNS was significantly larger when increasing blood pressure (p=0.0006). We, thus, found no advantages for the stentless aortic valves compared with stented prosthesis in terms of lower maximum or mean RNS values. Native valves have a significantly lower mean RNS value than all investigated bioprostheses. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Natural Origin Lycopene and Its "Green" Downstream Processing.

    Science.gov (United States)

    Papaioannou, Emmanouil H; Liakopoulou-Kyriakides, Maria; Karabelas, Anastasios J

    2016-01-01

    Lycopene is an abundant natural carotenoid pigment with several biological functions (well-known for its antioxidant properties) which is under intensive investigation in recent years. Lycopene chemistry, its natural distribution, bioavailability, biological significance, and toxicological effects are briefly outlined in the first part of this review. The second, major part, deals with various modern downstream processing techniques, which are assessed in order to identify promising approaches for the recovery of lycopene and of similar lipophilic compounds. Natural lycopene is synthesized in plants and by microorganisms, with main representatives of these two categories (for industrial production) tomato and its by-products and the fungus Blakeslea trispora, respectively. Currently, there is a great deal of effort to develop efficient downstream processing for large scale production of natural-origin lycopene, with trends strongly indicating the necessity for "green" and mild extraction conditions. In this review, emphasis is placed on final product safety and ecofriendly processing, which are expected to totally dominate in the field of natural-origin lycopene extraction and purification.

  18. Kappa-Electrons Downstream of the Solar Wind Termination Shock

    Science.gov (United States)

    Fahr, H. J.

    2017-12-01

    A theoretical description of the solar wind electron distribution function downstream of the termination shock under the influence of the shock-induced injection of overshooting KeV-energetic electrons will be presented. A kinetic phasespace transport equation in the bulk frame of the heliosheath plasma flow is developed for the solar wind electrons, taking into account shock-induced electron injection, convective changes, magnetic cooling processes and whistler wave-induced energy diffusion. Assuming that the local electron distribution under the prevailing Non-LTE conditions can be represented by a local kappa function with a local kappa parameter that varies with the streamline coordinates, we determine the parameters of the resulting, initial kappa distribution for the downstream electrons. From this initial function spectral electron fluxes can be derived and can be compared with those measured by the VOYAGER-1 spacecraft in the range between 40 to 70 KeV. It can then be shown that with kappa values around kappa = 6 one can in fact fit these data very satisfactorily. In addition it is shown that for isentropic electron flows kappa-distributed electrons have to undergo simultaneous changes of both parameters, i.e. kappa and theta, of the electron kappa function. It is also shown then that under the influence of energy sinks and sources the electron flux becomes non-isentropic with electron entropies changing along the streamline.

  19. Space autonomy as migration of functionality: the mars case

    NARCIS (Netherlands)

    Grant, T.; Bos, A.; Neerincx, M.; Soler, A.O.; Brauer, U.; Wolff, M.

    2006-01-01

    This paper develops Grandjean and Lecouat's insight that spacecraft autonomy can be seen as the migration of functionality from the ground segment to the space segment. Their insight is extended to manned planetary exploration missions and applied to an IT-based crew assistant for supporting manned

  20. Globalization, Migration and Development

    Directory of Open Access Journals (Sweden)

    George, Susan

    2002-01-01

    Full Text Available EnglishMigration may become the most important branch of demography in the earlydecades of the new millennium in a rapidly globalizing world. This paper discusses the causes, costsand benefits of international migration to countries of the South and North, and key issues of commonconcern. International migration is as old as national boundaries, though its nature, volume,direction, causes and consequences have changed. The causes of migration are rooted in the rate ofpopulation growth and the proportion of youth in the population, their education and training,employment opportunities, income differentials in society, communication and transportationfacilities, political freedom and human rights and level of urbanization. Migration benefits the Souththrough remittances of migrants, improves the economic welfare of the population (particularly womenof South countries generally, increases investment, and leads to structural changes in the economy.However, emigration from the South has costs too, be they social or caused by factors such as braindrain. The North also benefits by migration through enhancement of economic growth, development ofnatural resources, improved employment prospects, social development and through exposure toimmigrants' new cultures and lifestyles. Migration also has costs to the North such as of immigrantintegration, a certain amount of destabilization of the economy, illegal immigration, and socialproblems of discrimination and exploitation. Issues common to both North and South include impact onprivate investment, trade, international cooperation, and sustainable development. Both North andSouth face a dilemma in seeking an appropriate balance between importing South's labour or itsproducts and exporting capital and technology from the North.FrenchLa migration est sans doute devenue la partie la plus importante de la démographie des premières décennies du nouveau millénaire dans un monde qui change rapidement. Ce

  1. Upstream migration of Pacific lampreys in the John Day River, Oregon: Behavior, timing, and habitat use

    Science.gov (United States)

    Robinson, T. Craig; Bayer, J.M.

    2005-01-01

    Adult Pacific lamprey migration and habitat preferences for over-winter holding and spawning, and larval rearing in tributaries to the Columbia River are not well understood. The John Day River is one such tributary where larval and adult stages of this species have been documented, and its free-flowing character provided the opportunity to study migration of Pacific lampreys unimpeded by passage constraints. Forty-two adult Pacific lampreys were captured in the John Day River near its mouth during their upstream migration. Pacific lampreys were surgically implanted with radio transmitters and released onsite, and tracked by fixed-site, aerial, and terrestrial telemetry methods for nearly one year. Adults moved upstream exclusively at night, with a mean rate of 11.1 ?? 6.3 km/day. They halted upstream migration by September, and held a single position for approximately six months in the lateral margins of riffles and glides, using boulders for cover. More than half of Pacific lampreys resumed migration in March before ending movement in early May. Pacific lampreys that resumed migration in spring completed a median of 87% of their upstream migration before over-winter holding. Upon completing migration. Pacific lampreys briefly held position before beginning downstream movement at the end of May. Though not directly observed, halting migration and movement downstream were likely the result of spawning and death. Gains in adult Pacific lamprey passage through the Columbia River hydrosystem and tributaries may be made by improvements that would expedite migration during spring and summer and increase the quantity and variety of cover and refuge opportunities. ?? 2005 by the Northwest Scientific Association. All rights reserved.

  2. Migration and Remittances : Recent Developments and Outlook - Transit Migration

    OpenAIRE

    World Bank Group

    2018-01-01

    This Migration and Development Brief reports global trends in migration and remittance flows, as well as developments related to the Global Compact on Migration (GCM), and the Sustainable Development Goal (SDG) indicators for volume of remittances as percentage of gross domestic product (GDP) (SDG indicator 17.3.2), reducing remittance costs (SDG indicator 10.c.1) and recruitment costs (SD...

  3. THE ROMANIAN MIGRATIONAL EVOLUTION PHENOMENON

    Directory of Open Access Journals (Sweden)

    Cristian Raluca

    2009-05-01

    Full Text Available In our contemporary democratic society the migration phenomenon meets unknown valences in any previous societies. Free will and right to self-determination, much exploited by the XX century society., raised the possibility of interpretation of migration

  4. Social effects of migration in receiving countries.

    Science.gov (United States)

    Ohndorf, W

    1989-06-01

    This paper examines the impact of post-1945 migration into Western, Middle, and Northern Europe from Southern Europe, Turkey, and Northern Africa, and migration to the traditional immigration countries by Asian and Latin American immigrants, on the social structures of receiving countries. Between 1955 and 1974, 1) traditional migration to the US and Australia became less important for European countries while traditional receiving countries accepted many immigrants from developing countries; and 2) rapid economic revival in Western and Northern Europe caused a considerable labor shortage which was filled by migrant workers especially from Southern Europe, Turkey, and Northern Africa, who stayed only until they reached their economic goals. Since 1974, job vacancies have declined and unemployment has soared. This employment crisis caused some migrants 1) to return to their countries of origin, 2) to bring the rest of their families to the receiving country, or 3) to lengthen their stay considerably. The number of refugees has also significantly increased since the mid-970s, as has the number of illegal migrants. After the mid-1970s, Europe began to experience integration problems. The different aspects of the impact of migration on social structures include 1) improvement of the housing situation for foreigners, 2) teaching migrants the language of the receiving country, 3) solving the unemployment problem of unskilled migrants, 4) improvement of educational and vocational qualifications of 2nd generation migrants, 5) development of programs to help unemployed wives of migrants to learn the language and meet indigenous women, 6) encouraging migrants to maintain their cultural identity and assisting them with reintegration if they return to their original country, 7) coping with the problems of refugees, and 8) solving the problems of illegal migration. Almost all receiving countries now severely restrict further immigration. [Those policies should result in

  5. International migration and the gender

    OpenAIRE

    Koropecká, Markéta

    2010-01-01

    My bachelor thesis explores the connection between international migration and gender. Gender, defined as a social, not a biological term, has a huge impact on the migration process. Statistics and expert studies that have been gender sensitive since 1970s demonstrate that women form half of the amount of the international migrants depending on the world region and representing a wide range of the kinds of international migration: family formation and reunification, labour migration, illegal ...

  6. Effect of shear stress on the migration of hepatic stellate cells.

    Science.gov (United States)

    Sera, Toshihiro; Sumii, Tateki; Fujita, Ryosuke; Kudo, Susumu

    2018-01-01

    When the liver is damaged, hepatic stellate cells (HSCs) can change into an activated, highly migratory state. The migration of HSCs may be affected by shear stress due not only to sinusoidal flow but also by the flow in the space of Disse because this space is filled with blood plasma. In this study, we evaluated the effects of shear stress on HSC migration in a scratch-wound assay with a parallel flow chamber. At regions upstream of the wound area, the migration was inhibited by 0.6 Pa and promoted by 2.0 Pa shear stress, compared to the static condition. The platelet-derived growth factor (PDGF)-BB receptor, PDGFR-β, was expressed in all conditions and the differences were not significant. PDGF increased HSC migration, except at 0.6 Pa shear stress, which was still inhibited. These results indicate that another molecular factor, such as PDGFR-α, may act to inhibit the migration under low shear stress. At regions downstream of the wound area, the migration was smaller under shear stress than under the static condition, although the expression of PDGFR-β was significantly higher. In particular, the migration direction was opposite to the wound area under high shear stress; therefore, migration might be influenced by the intercellular environment. Our results indicate that HSC migration was influenced by shear stress intensity and the intercellular environment.

  7. Youth Labor Migration in Nepal

    OpenAIRE

    Bossavie, Laurent; Denisova, Anastasiya

    2018-01-01

    This descriptive study investigates internal and external labor migration by Nepalese youth. External labor migration is separated into the flow to India, which is unregulated, and the flow to other countries, which typically takes the form of temporary contract migration to countries with bilateral labor agreements with Nepal (referred to in Nepal as foreign employment). The study finds t...

  8. Musei del migration heritage / Migration heritage museums

    Directory of Open Access Journals (Sweden)

    Patrizia Dragoni

    2015-01-01

    Since the second half of the 1960s of the 20th century, a profound cultural innovation was accompanied to the radical change in the social, political and economic climate. The anthropological notion of culture as opposed to idealistic vision, the unusual and strong interest in material culture, the enunciation of the concept of cultural property by the Franceschini Commission, the luck of the Public History bring a change of the disciplinary statutes of historical sciences, which begin to attend to social history, focusing on the spontaneous sources of information and initiating experiences of oral history. To all this a remarkable transformation of the themes and of the social function of museums is added. This paper illustrates, in relation to this more general context, the foundation and the dissemination of museums dedicated to the history of migration in Italy and in the world, enunciates their possible social utility for the integration of present migrants in Italy and illustrates, by way of example, the museum recently opened in Recanati.

  9. Downstream ecological effects of dams: A geomorphic perspective

    International Nuclear Information System (INIS)

    Ligon, F.K.; Dietrich, W.E.; Trush, W.J.

    1995-01-01

    The damming of a river changes the flow of water, sediment, nutrients, energy, and biota, interrupting and altering most of a river's ecological processes. This article discusses the importance of geomorphological analysis in river conservation and management. To illustrate how subtle geomorphological adjustments may profoundly influence the ecological relationships downstream from dames, three case studies are presented. Then a geomorphically based approach for assessing and possibly mitigating some of the environmental effects of dams by tailoring dam designed and operation is outlined. The cases are as follows: channel simplification and salmon decline on the McKenzie River in Oregon; Channel incision and reduced floodplain inundation on the Oconee river in Georgia; Increased stability of a braided river in New Zealand's south island. 41 refs., 10 figs., 1 tab

  10. Continuous downstream processing for high value biological products: A Review.

    Science.gov (United States)

    Zydney, Andrew L

    2016-03-01

    There is growing interest in the possibility of developing truly continuous processes for the large-scale production of high value biological products. Continuous processing has the potential to provide significant reductions in cost and facility size while improving product quality and facilitating the design of flexible multi-product manufacturing facilities. This paper reviews the current state-of-the-art in separations technology suitable for continuous downstream bioprocessing, focusing on unit operations that would be most appropriate for the production of secreted proteins like monoclonal antibodies. This includes cell separation/recycle from the perfusion bioreactor, initial product recovery (capture), product purification (polishing), and formulation. Of particular importance are the available options, and alternatives, for continuous chromatographic separations. Although there are still significant challenges in developing integrated continuous bioprocesses, recent technological advances have provided process developers with a number of attractive options for development of truly continuous bioprocessing operations. © 2015 Wiley Periodicals, Inc.

  11. Downstream and upstream extension of the House of Quality

    DEFF Research Database (Denmark)

    Holmen, Elsebeth; Kristensen, Preben Sander

    . The transformation processes and characteristics constituting this fan were based on the knowledge possessed by the company before entering into development interaction with suppliers. If it is these characteristics which are used to express the demands of the company in the subsequent interaction process, much......Executive summary 1. During 1993-94 the authors followed a product development process in a Danish butter cookie company. The process was structured according to the Quality Function Deployment technique House of Quality. Originally, the intention was to study the prototyping process that we...... a discussion in a diabetics end-user focus group. During a series of meetings, the production manager and the sales manager transformed attributes int characteristics and constructed Houses of Quality for a sugar-free cookie. 2. Downstream on its way to the end-user, the product passes through a chain of users...

  12. Mergers and acquisitions of downstream facilities by producing countries

    Energy Technology Data Exchange (ETDEWEB)

    Ligon, D.R.

    1988-01-01

    The author discusses a phenomenon that he calls the ''re-integration'' or ''re-coupling'' of the worldwide oil industry, as foreign, particularly OPEC, producers are becoming directly involved with downstream operations in their most important markets. This phenomenon already has produced some far-reaching consequences that will become even more important and pervasive in the near future. First, he describes the factors and logic that led to these arrangements. Next, he outlines some of their practical considerations and implications. While some of the market factors described are applicable to any non-integrated producer, he spends most of his time discussing OPEC and ''neo-OPEC'' producers such as Mexico. These are the people doing the deals and are therefore probably of greatest interest.

  13. The downstream externalities of harvesting rainwater in semi-arid watersheds: an Indian case study

    NARCIS (Netherlands)

    Bouma, J.A.; Biggs, T.W.; Bouwer, L.M.

    2011-01-01

    Water-related investment projects affect downstream water availability, and therefore should account for these externalities. Few projects do, however, owing to lack of awareness, lack of data and difficulty in linking upstream investments to downstream effects. This article assesses the downstream

  14. From gravel to sand. Downstream fining of bed sediments in the lower river Rhine

    NARCIS (Netherlands)

    Frings, R.M.

    2007-01-01

    A common characteristic of many rivers is the tendency for bed sediments to become finer in downstream direction. This phenomenon, which is generally known as downstream fining, has a strong effect on the morphologic and hydrodynamic behaviour of a river. The fundamental causes of downstream

  15. Religion, migration og integration

    DEFF Research Database (Denmark)

    Borup, Jørn

    2010-01-01

    Sammenhængen mellem religion og integration har de sidste år været genstand for debat. Artiklen kommer ind på begreber og sammenhænge relateret til området (migration, diaspora, assimilation, etnicitet, kultur) og ser på religionens mulige rolle som negativ eller positiv ressource i integrationss......Sammenhængen mellem religion og integration har de sidste år været genstand for debat. Artiklen kommer ind på begreber og sammenhænge relateret til området (migration, diaspora, assimilation, etnicitet, kultur) og ser på religionens mulige rolle som negativ eller positiv ressource i...

  16. Immunohistochemical evalulation of activated Ras and Rac1 as potential downstream effectors of aquaporin-5 in breast cancer in vivo.

    Science.gov (United States)

    Jensen, Helene H; Login, Frédéric H; Park, Ji-Young; Kwon, Tae-Hwan; Nejsum, Lene N

    2017-11-25

    Aberrant levels of aquaporin-5 (AQP5) expression have been observed in several types of cancer, including breast cancer, where AQP5 overexpression is associated with metastasis and poor prognosis. In cultured cancer cells, AQP5 facilitates cell migration and activates Ras signaling. Both increased cell migration and Ras activation are associated with cancer metastasis, but so far it is unknown if AQP5 also affects these processes in vivo. Therefore, we investigated if high AQP5 expression in breast cancer tissue correlated with increased activation of Ras and of Rac1, which is a GTPase also involved in cell migration. This was accomplished by immunohistochemical analysis of invasive ductal carcinoma of breast tissue sections from human patients, followed by qualitative and quantitative correlation analysis between AQP5 and activated Ras and Rac1. Immunohistochemistry revealed that activation of Ras and Rac1 was positively correlated. There was, however, no correlation between high AQP5 expression and activation of Ras, whereas a nonsignificant, but positive, tendency between the levels of AQP5 and activated Rac1 levels was observed. In summary, this is the first report that correlates AQP5 expression levels to downstream signaling partners in breast cancer tissue sections. The results suggest Rac1 as a potential downstream signaling partner of AQP5 in vivo. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Operating multireservoir hydropower systems for downstream water quality

    International Nuclear Information System (INIS)

    Hayes, D.F.

    1990-01-01

    Hydropower reservoir operations often impact tailwater quality and water quality in the stream or river below the impoundment for many miles. Determining optimal operating strategies for a system of hydropower reservoirs involves solving a highly dimensional nonlinear, nonconvex optimization problem. This research adds the additional complexities of downstream water quality considerations within the optimization formulation to determine operating strategies for a system of hydropower reservoirs operating in series (tandem) or parallel. The formulation was used to determine operating strategies for six reservoirs of the upper Cumberland river basin in Tennessee and Kentucky. Significant dissolved oxygen (DO) violations occur just upstream of Nashville, Tennessee below Old Hickory dam during the months of August and September. Daily reservoir releases were determined for the period of June through September which would produce the maximum hydropower revenue while meeting downstream water quality objectives. Optimal releases for three operational strategies were compared to historical operations for the years 1985, 1986, and 1988. These strategies included: spilling as necessary to meet water quality criteria, near normal operation (minimal spills), and drawdown of reservoirs as necessary to meet criteria without spills. Optimization results showed an 8% to 15% hydropower loss may be necessary to meet water quality criteria through spills and a 2% to 9% improvement in DO below Old Hickory may be possible without significant spills. Results also showed that substantial increases in initial headwater elevations would be necessary to meet daily DO criteria and avoid spills. The optimal control theory algorithm used to solve the problem proved to be an efficient and robust solver of this large optimization problem

  18. Downstream cumulative effects of land use on freshwater communities

    Science.gov (United States)

    Kuglerová, L.; Kielstra, B. W.; Moore, D.; Richardson, J. S.

    2015-12-01

    Many streams and rivers are subject to disturbance from intense land use such as urbanization and agriculture, and this is especially obvious for small headwaters. Streams are spatially organized into networks where headwaters represent the tributaries and provide water, nutrients, and organic material to the main stems. Therefore perturbations within the headwaters might be cumulatively carried on downstream. Although we know that the disturbance of headwaters in urban and agricultural landscapes poses threats to downstream river reaches, the magnitude and severity of these changes for ecological communities is less known. We studied stream networks along a gradient of disturbance connected to land use intensity, from urbanized watersheds to watersheds placed in agricultural settings in the Greater Toronto Area. Further, we compared the patterns and processes found in the modified watershed to a control watershed, situated in a forested, less impacted landscape. Preliminary results suggest that hydrological modifications (flash floods), habitat loss (drainage and sewer systems), and water quality issues of small streams in urbanized and agricultural watersheds represent major disturbances and threats for aquatic and riparian biota on local as well as larger spatial scales. For example, communities of riparian plants are dominated by species typical of the land use on adjacent uplands as well as the dominant land use on the upstream contributing area, instead of riparian obligates commonly found in forested watersheds. Further, riparian communities in disturbed environments are dominated by invasive species. The changes in riparian communities are vital for various functions of riparian vegetation. Bank erosion control is suppressed, leading to severe channel transformations and sediment loadings in urbanized watersheds. Food sources for instream biota and thermal regimes are also changed, which further triggers alterations of in-stream biological communities

  19. Grain boundary migration

    International Nuclear Information System (INIS)

    Dimitrov, O.

    1975-01-01

    Well-established aspects of grain-boundary migration are first briefly reviewed (influences of driving force, temperature, orientation and foreign atoms). Recent developments of the experimental methods and results are then examined, by considering the various driving of resistive forces acting on grain boundaries. Finally, the evolution in the theoretical models of grain-boundary motion is described, on the one hand for ideally pure metals and, on the other hand, in the presence of solute impurity atoms [fr

  20. Ventriculoperitoneal Shunt Migration

    Directory of Open Access Journals (Sweden)

    Justin P Puller

    2017-01-01

    Full Text Available History of present illness: A 40-year-old female presented to our ED with left upper abdominal pain and flank pain. The pain had begun suddenly 2 hours prior when she was reaching into a freezer to get a bag of frozen vegetables. She described the pain as sharp, constant, severe, and worse with movements and breathing. The pain radiated to the left shoulder. On review of systems, the patient had mild dyspnea and nausea. She denied fever, chills, headache, vision changes, vomiting, or urinary symptoms. Her medical history was notable for obstructive sleep apnea, gastroesophageal reflux disease, arthritis, fibromyalgia, depression, obesity, and idiopathic intracranial hypertension. For the latter, she had a VP (ventriculoperitoneal shunt placed 14 years prior to this visit. She had a history of 2 shunt revisions, the most recent 30 days before this ED visit. Significant findings: An immediate post-op abdominal x-ray performed after the patient’s VP shunt revision 30 days prior to this ED visit reveals the VP shunt tip in the mid abdomen. A CT of the abdomen performed on the day of the ED visit reveals the VP shunt tip interposed between the spleen and the diaphragm. Discussion: VP shunts have been reported to migrate to varied locations in the thorax and abdomen. Incidence of abdominal complications of VP shunt placement ranges from 10%-30%, and can include pseudocyst formation, migration, peritonitis, CSF ascites, infection, and viscus perforation. Incidence of distal shunt migration is reported as 10%, and most previously reported cases occurred in pediatric patients.1 A recent retrospective review cited BMI greater than thirty and previous shunt procedure as risk factors for distal shunt migration.2 The patient in the case presented had a BMI of 59 and 3 previous shunt procedures.

  1. Conservation physiology of animal migration

    Science.gov (United States)

    Lennox, Robert J.; Chapman, Jacqueline M.; Souliere, Christopher M.; Tudorache, Christian; Wikelski, Martin; Metcalfe, Julian D.; Cooke, Steven J.

    2016-01-01

    Migration is a widespread phenomenon among many taxa. This complex behaviour enables animals to exploit many temporally productive and spatially discrete habitats to accrue various fitness benefits (e.g. growth, reproduction, predator avoidance). Human activities and global environmental change represent potential threats to migrating animals (from individuals to species), and research is underway to understand mechanisms that control migration and how migration responds to modern challenges. Focusing on behavioural and physiological aspects of migration can help to provide better understanding, management and conservation of migratory populations. Here, we highlight different physiological, behavioural and biomechanical aspects of animal migration that will help us to understand how migratory animals interact with current and future anthropogenic threats. We are in the early stages of a changing planet, and our understanding of how physiology is linked to the persistence of migratory animals is still developing; therefore, we regard the following questions as being central to the conservation physiology of animal migrations. Will climate change influence the energetic costs of migration? Will shifting temperatures change the annual clocks of migrating animals? Will anthropogenic influences have an effect on orientation during migration? Will increased anthropogenic alteration of migration stopover sites/migration corridors affect the stress physiology of migrating animals? Can physiological knowledge be used to identify strategies for facilitating the movement of animals? Our synthesis reveals that given the inherent challenges of migration, additional stressors derived from altered environments (e.g. climate change, physical habitat alteration, light pollution) or interaction with human infrastructure (e.g. wind or hydrokinetic turbines, dams) or activities (e.g. fisheries) could lead to long-term changes to migratory phenotypes. However, uncertainty remains

  2. Many Faces of Migrations

    Directory of Open Access Journals (Sweden)

    Milica Antić Gaber

    2013-12-01

    We believe that in the present thematic issue we have succeeded in capturing an important part of the modern European research dynamic in the field of migration. In addition to well-known scholars in this field several young authors at the beginning their research careers have been shortlisted for the publication. We are glad of their success as it bodes a vibrancy of this research area in the future. At the same time, we were pleased to receive responses to the invitation from representatives of so many disciplines, and that the number of papers received significantly exceeded the maximum volume of the journal. Recognising and understanding of the many faces of migration are important steps towards the comprehensive knowledge needed to successfully meet the challenges of migration issues today and even more so in the future. It is therefore of utmost importance that researchers find ways of transferring their academic knowledge into practice – to all levels of education, the media, the wider public and, of course, the decision makers in local, national and international institutions. The call also applies to all authors in this issue of the journal.

  3. Migration Process Evolution in Europe

    Directory of Open Access Journals (Sweden)

    Carmen Tudorache

    2006-08-01

    Full Text Available The migration phenomenon has always existed, fluctuating by the historic context, the economic, political, social and demographic disparities between the Central and East European countries and the EU Member States, the interdependencies between the origin and receiving countries and the European integration process evolutions. In the European Union, an integrated and inclusive approach of the migration issue is necessary. But a common policy on migration rests an ambitious objective. A common approach of the economic migration management and the harmonization of the migration policies of the Member States represented a challenge for the European Union and will become urgent in the future, especially due to the demographic ageing.

  4. Migrations in Slovenian geography textbooks

    Directory of Open Access Journals (Sweden)

    Jurij Senegačnik

    2013-12-01

    Full Text Available In Slovenia, the migrations are treated in almost all geographical textbooks for different levels of education. In the textbooks for the elementary school from the sixth to ninth grade, students acquire knowledge of the migrations by the inductive approach. Difficulty level of treatment and quantity of information are increasing by the age level. In the grammar school program a trail of gaining knowledge on migration is deductive. Most attention is dedicated to migrations in general geography textbooks. The textbooks for vocational and technical school programs deal with migrations to a lesser extent and with different approaches.

  5. Determinants of International Migration: The Nigerian Experience

    Directory of Open Access Journals (Sweden)

    Samuel Antwi Darkwah

    2014-01-01

    Full Text Available This paper examines some determinants of international migration in Nigeria using annual time series data spanning the period 1991–2011. Using ordinary least square regression method, the results indicate that the level of unemployment, migrants’ remittances and population growth are the key determinants of emigration from Nigeria to other countries, statistically significant at 0.01 level.In a country where unemployment rate is very high, this movement is likely to help in reducing pressures on the labour market. Migrants’ remittances might also help in alleviating poverty within households. Migrants’ remittance to Nigeria has surpassed both Foreign Direct Investment and Net Official Development Assistance inflows, making it one amongst the major sources of foreign earnings to Nigeria. Nigerians will continue to migrate to other parts of the world so long as the reasons or causes for their movement are not fully addressed i.e. if political and socioeconomic issues in the country do not improve. The Nigerian government should as a matter of urgency, create better jobs and conducive environment in order to stop people from migrating while at the same time encouraging its skilled labour abroad to return home to help in national development.

  6. Upstream and Downstream Co-inhibition of Mitogen-Activated Protein Kinase and PI3K/Akt/mTOR Pathways in Pancreatic Ductal Adenocarcinoma

    Directory of Open Access Journals (Sweden)

    Matthew H. Wong

    2016-07-01

    Full Text Available BACKGROUND: Extensive cross talk exists between PI3K/Akt/mTOR and mitogen-activated protein kinase (MAPK pathways, and both are upregulated in pancreatic ductal adenocarcinoma (PDAC. Our previous study suggested that epidermal growth factor receptor inhibitor erlotinib which acts upstream of these pathways acts synergistically with PI3K inhibitors in PDAC. Horizontal combined blockade upstream and downstream of these two pathways is therefore explored. METHODS: Erlotinib paired with PI3K inhibitor (BYL719 was tested against erlotinib plus dual PI3K/mTOR inhibitor BEZ-235, and MEK inhibitor (PD98059 plus BEZ235, on five primary PDAC cell lines and on two pairs of parent and erlotinib-resistant (ER cell lines. A range of in vitro assays including cell proliferation, Western blotting, migration, clonogenic, cell cycle, and apopotic assays was used to test for the efficacy of combined blockade. RESULTS: Dual downstream blockade of the MAPK and PAM pathways was more effective in attenuating downstream molecular signals. Synergy was demonstrated for erlotinib and BEZ235 and for PD-98059 and BEZ-235. This resulted in a trend of increased growth cell cycle arrest, apoptosis, cell proliferation, and colony and migration suppression. This combination showed more efficacy in cell lines with acquired resistance to erlotinib. CONCLUSIONS: The additional mTOR blockade provided by BEZ235 in combined blockade resulted in increased anticancer effect. The hypersensitivity of ER cell lines to additional mTOR blockade suggested PAM pathway oncogenic dependence via mTOR. Dual downstream combined blockade of MAPK and PAM pathways with MEK and PI3K/mTOR inhibitor appeared most effective and represents an attractive therapeutic strategy against pancreatic cancer and its associated drug resistance.

  7. The new economics of labour migration and the role of remittances in the migration process.

    Science.gov (United States)

    Taylor, J E

    1999-01-01

    This analysis considers international migration remittances and their impact on development in migrant-sending areas. The new economics of labor migration (NELM) posit that remittances lessen production and market constraints faced by households in poor developing countries. The article states that remittances may be a positive factor in economic development, which should be nurtured by economic policies. The impact of remittances and migration on development varies across locales and is influenced by migrants' remittance behavior and by economic contexts. Criteria for measuring development gains may include assessments of income growth, inequity, and poverty alleviation. It is hard to gauge the level of remittances, especially when remittances may not flow through formal banking systems. The International Monetary Fund distinguishes between worker remittances sent home for over 1 year; employee compensation including the value of in-kind benefits for under 1 year; and the net worth of migrants who move between countries. This sum amounted to under $2 billion in 1970 and $70 billion in 1995. The cumulative sum of remittances, employee compensation, and transfers was almost $1 trillion, of which almost 66% was worker remittances, 25% was employee compensation, and almost 10% was transfers during 1980-95. Total world remittances surpass overseas development assistance. Remittances are unequally distributed across and between countries. Migration research does not adequately reveal the range and complexity of impacts. Push factors can limit options for use of remittances to stimulate development.

  8. Corrosion impact of reductant on DWPF and downstream facilities

    Energy Technology Data Exchange (ETDEWEB)

    Mickalonis, J. I. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Imrich, K. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Jantzen, C. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Murphy, T. H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Wilderman, J. E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2014-12-01

    Glycolic acid is being evaluated as an alternate reductant in the preparation of high level waste for the Defense Waste Processing Facility (DWPF) at the Savannah River Site (SRS). During processing, the glycolic acid is not completely consumed and small quantities of the glycolate anion are carried forward to other high level waste (HLW) facilities. The impact of the glycolate anion on the corrosion of the materials of construction throughout the waste processing system has not been previously evaluated. A literature review had revealed that corrosion data in glycolate-bearing solution applicable to SRS systems were not available. Therefore, testing was recommended to evaluate the materials of construction of vessels, piping and components within DWPF and downstream facilities. The testing, conducted in non-radioactive simulants, consisted of both accelerated tests (electrochemical and hot-wall) with coupons in laboratory vessels and prototypical tests with coupons immersed in scale-up and mock-up test systems. Eight waste or process streams were identified in which the glycolate anion might impact the performance of the materials of construction. These streams were 70% glycolic acid (DWPF feed vessels and piping), SRAT/SME supernate (Chemical Processing Cell (CPC) vessels and piping), DWPF acidic recycle (DWPF condenser and recycle tanks and piping), basic concentrated recycle (HLW tanks, evaporators, and transfer lines), salt processing (ARP, MCU, and Saltstone tanks and piping), boric acid (MCU separators), and dilute waste (HLW evaporator condensate tanks and transfer line and ETF components). For each stream, high temperature limits and worst-case glycolate concentrations were identified for performing the recommended tests. Test solution chemistries were generally based on analytical results of actual waste samples taken from the various process facilities or of prototypical simulants produced in the laboratory. The materials of construction for most vessels

  9. International assistance. Licensing assistance project

    International Nuclear Information System (INIS)

    Aleev, A.

    1999-01-01

    Description of licensing assistance project for VATESI is presented. In licensing of unit No.1 of INPP VATESI is supported by many western countries. Experts from regulatory bodies or scientific organizations of those countries assist VATESI staff in reviewing documentation presented by INPP. Among bilateral cooperation support is provided by European Commission through Phare programme

  10. Japanese migration in contemporary Japan: economic segmentation and interprefectural migration.

    Science.gov (United States)

    Fukurai, H

    1991-01-01

    This paper examines the economic segmentation model in explaining 1985-86 Japanese interregional migration. The analysis takes advantage of statistical graphic techniques to illustrate the following substantive issues of interregional migration: (1) to examine whether economic segmentation significantly influences Japanese regional migration and (2) to explain socioeconomic characteristics of prefectures for both in- and out-migration. Analytic techniques include a latent structural equation (LISREL) methodology and statistical residual mapping. The residual dispersion patterns, for instance, suggest the extent to which socioeconomic and geopolitical variables explain migration differences by showing unique clusters of unexplained residuals. The analysis further points out that extraneous factors such as high residential land values, significant commuting populations, and regional-specific cultures and traditions need to be incorporated in the economic segmentation model in order to assess the extent of the model's reliability in explaining the pattern of interprefectural migration.

  11. Labour migration from Turkey.

    Science.gov (United States)

    Uner, S

    1988-01-01

    This study is concerned with Turkish labor migration to Western Europe. Earlier and recent patterns of labor migration, characteristics of migrants by occupation, area of destination, and by geographical origins are discussed. Economic and demographic consequences of labor migration are also analyzed. It is estimated that Turkey's population will reach 73 million at the year 2000 with the present growth rate of 2.48% annually. Considering the efforts made to slow down the present high fertility rates and assuming that the decrease in labor force participation during 1970-1980 continues, the author concludes that the labor supply will increase with a growth rate of 2% annually for the next 13-15 years. Thus, the labor supply will reach 26.6 million people in the year 2000 from the 1980 level of 17.8 million. Assuming also that the income/employment elasticity of .25 which was observed throughout the period of 1960-1980 will not change until 2000, the annual growth rate of employment may be estimated as 1.5%. Thus, the number of people employed will reach 20 million in the year 1990 and 23.2 million in the year 2000. 8.8 million people will join the labor market as new entrants between 1980 and 2000. Only 6 million people out of 8.8 million will be employed. Thus, in the year 2000, it is estimated that 2.8 million new unemployed people will be added to the already open unemployment figure 1980 census data give the number of unemployed as .6 million people. Adding the 2.8 million new unemployed to this figure totals 3.4 million unemployed in 2000. The State Planning Organization's estimate of labor surplus for 1980 was 2.5 million people. When 2.8 million unemployed people are added to this figure, the labor surplus for the year 2000 reaches 5.3 million people.

  12. ILO - International Migration Programme.

    Science.gov (United States)

    Boudraa, Miriam

    2011-01-01

    In a wide International Context characterised not only by the economical development but also by the social, cultural, political and individual development, we witness more and more to a exchange between the developed and the developing countries, which can be translated especially in the migration of the work force. In theory, all countries are either countries of origin either countries of transit or destination, and they are all responsible for the rights of migrant workers by promoting the rights, by monitoring and by preventing the abusive conditions. The process of migration of the workforce can be divided into three stages: the first coincides with the period prior to departure, the second is represented by the aftermath of the departure and the period of stay in the country of destination, the third stage corresponds to the return in the country of origin. The workers must be protected throughout this process by the international organizations that perform the catalytic role of communication and exchange between countries, for the only purpose of protecting the rights of immigrant and/or immigrants workers. The responsibility for the protection of workers is divided among the various players in the International Labour Organisation. Every country has to apply measures according to the international standards regarding workers' rights, standards that guide the various countries in the formulation and implementation of their policies and legislation. These standards are suggested by International Conventions, the ILO Conventions and other international instruments such as the human rights instrument. There has been a big step forward once the ILO Fundamental Conventions and Conventions on Migrant Workers where implemented and this implementation represented the use of the Guidelines "ILO Multilateral Framework on Labour Migration".

  13. Urbanization, Migration, Information

    Directory of Open Access Journals (Sweden)

    Konstantin Lidin

    2016-05-01

    Full Text Available In the contemporary world urbanization becomes a large-scale process. Huge flows of people migrate from poorer districts to the cities with a higher level of consumption. It takes migrants about 15-25 years to give up their traditional ascetic way of life. In this period the ‘new citizens’ try to arrange compact settlements with an archaic way of life, insanitary conditions, high criminogenity and an authoritative local self-government. The processes of formation and decay of the ascetic enclave are viewed through the example of the ‘Shanghai’ trading neighborhood in Irkutsk.

  14. Neuronal Migration and Neuronal Migration Disorder in Cerebral Cortex

    OpenAIRE

    SUN, Xue-Zhi; TAKAHASHI, Sentaro; GUI, Chun; ZHANG, Rui; KOGA, Kazuo; NOUYE, Minoru; MURATA, Yoshiharu

    2002-01-01

    Neuronal cell migration is one of the most significant features during cortical development. After final mitosis, neurons migrate from the ventricular zone into the cortical plate, and then establish neuronal lamina and settle onto the outermost layer, forming an "inside-out" gradient of maturation. Neuronal migration is guided by radial glial fibers and also needs proper receptors, ligands, and other unknown extracellular factors, requests local signaling (e.g. some emitted by the Cajal-Retz...

  15. Cytoglobin inhibits migration through PI3K/AKT/mTOR pathway in fibroblast cells.

    Science.gov (United States)

    Demirci, Selami; Doğan, Ayşegül; Apdik, Hüseyin; Tuysuz, Emre Can; Gulluoglu, Sukru; Bayrak, Omer Faruk; Şahin, Fikrettin

    2018-01-01

    Cell proliferation and migration are crucial in many physiological processes including development, cancer, tissue repair, and wound healing. Cell migration is regulated by several signaling molecules. Identification of genes related to cell migration is required to understand molecular mechanism of non-healing chronic wounds which is a major concern in clinics. In the current study, the role of cytoglobin (CYGB) gene in fıbroblast cell migration and proliferation was described. L929 mouse fibroblast cells were transduced with lentiviral particles for CYGB and GFP, and analyzed for cell proliferation and migration ability. Fibroblast cells overexpressing CYGB displayed decreased cell proliferation, colony formation capacity, and cell migration. Phosphorylation levels of mTOR and two downstream effectors S6 and 4E-BP1 which take part in PI3K/AKT/mTOR signaling declined in CYGB-overexpressing cells. Microarray analysis indicated that CYGB overexpression leads to downregulation of cell proliferation, migration, and tumor growth associated genes in L929 cell line. This study demonstrated the role of CYGB in fibroblast cell motility and proliferation. CYGB could be a promising candidate for further studies as a potential target for diseases related to cell migration such as cancer and chronic wound treatment.

  16. The relationship of mineral and geochemical composition to artificial radionuclide partitioning in Yenisei river sediments downstream from Krasnoyarsk.

    Science.gov (United States)

    Bondareva, Lydia

    2012-06-01

    Discharges from the Mining-and-Chemical Combine (MCC) of Rosatom, downstream from Krasnoyarsk, resulted in radioactive contamination of sediments of the River Yenisei. The concentration of artificial gamma-emitting radionuclides ((137)Cs, (60)Co, (152)Eu, and (241)Am) was determined with the objective to analyze the migration processes leading to the transport of these radionuclides. The content of artificial radionuclides in the surface layers of the study area varied in wide ranges: (137)Cs-318-1,800 Bq/kg, (60)Co-87-720 Bq/kg, (152)Eu-12-287 Bq/kg and (241)Am-6-76 Bq/kg. There was a sequence of migration of radionuclides investigated in the surface layer of sediments that were collected in the near zone of influence of the MCC: (241)Am ≈ (152)Eu > (60)Co > (137)Cs. Radionuclide species have been found to be directly related to sediment structure and composition.

  17. Downstream process development in biotechnological itaconic acid manufacturing.

    Science.gov (United States)

    Magalhães, Antonio Irineudo; de Carvalho, Júlio Cesar; Medina, Jesus David Coral; Soccol, Carlos Ricardo

    2017-01-01

    Itaconic acid is a promising chemical that has a wide range of applications and can be obtained in large scale using fermentation processes. One of the most important uses of this biomonomer is the environmentally sustainable production of biopolymers. Separation of itaconic acid from the fermented broth has a considerable impact in the total production cost. Therefore, optimization and high efficiency downstream processes are technological challenges to make biorefineries sustainable and economically viable. This review describes the current state of the art in recovery and purification for itaconic acid production via bioprocesses. Previous studies on the separation of itaconic acid relying on operations such as crystallization, precipitation, extraction, electrodialysis, diafiltration, pertraction, and adsorption. Although crystallization is a typical method of itaconic acid separation from fermented broth, other methods such as membrane separation and reactive extraction are promising as a recovery steps coupled to the fermentation, potentially enhancing the overall process yield. Another approach is adsorption in fixed bed columns, which efficiently separates itaconic acid. Despite recent advances in separation and recovery methods, there is still space for improvement in IA recovery and purification.

  18. Simulation of hanging dams downstream of Ossauskoski power plant

    Energy Technology Data Exchange (ETDEWEB)

    Aaltonen, J.; Huokuna, M. [Finnish Environment Inst., Helsinki (Finland); Severinkangas, K.; Talvensaari, M. [Kemijoki Oy, Rovaniemi (Finland)

    2008-07-01

    Sixteen power plants have been constructed along Finland's Kemijoki River for hydroelectric power production. The Ossauskoski facility has recently undergone major renovations and upgrade, making it the sixth largest hydroelectric power plant in Finland, with a new capacity of 124 MW and an annual energy output of 501 GWh. The increase in power output and discharge may cause changes in ice conditions downstream of the power plant. The section of the river is already subjected to frazil ice problems and hanging dam formation. Discharges and adverse effects of frazil ice phenomena are likely to increase due to climate change, resulting in harm for hydropower production and the environment, particularly in flow regulated rivers where winter discharges are higher than natural discharges. As such, a study was launched to investigate a dredge plan suggested by by the electric utility Kemijoki Oy. The project involved mapping the river bed topography to identify the location and extent of hanging dams. A sounding device and ground penetrating radar was used to find the thaw regions in the ice cover. The JJT numerical river ice model was effectively used to study the effect of hanging dams on water levels. However, the ice bridging phenomena was not modelled in a reliable way by the JJT model and will be modelled in the future using the CRISSP2D numerical model. 5 refs., 11 figs.

  19. Energy taxes and subsidies downstream: transparency and dissemination

    International Nuclear Information System (INIS)

    Aissaour, A.

    2001-01-01

    The reasons why governments levy taxes are discussed with special reference to the energy sector. The article focuses on the quantitative aspect of policies and gives a guide to the relevant statistical sources. It summarises the basis of taxes and subsidies and discusses the incidence of energy taxation together with the structure of taxes and subsidies in energy downstream. It reviews the main sources of data and issues highlighted by published statistics and the impact of taxes levied on the consumption of energy products and other taxes (e.g. VAT) which directly affect end-user prices. Production-based levies such as royalties, petroleum revenue taxes, windfall taxes and import and export taxes on fuels are not discussed. The paper is presented under the sub-headings of (i) theoretical foundations in a nutshell; (ii) the incidence of taxation; (iii) the structure and main features of energy taxation (iv) base rate and level of taxation (v) sources of data and methods and (vi) observability and comparability

  20. Gellan Gum: Fermentative Production, Downstream Processing and Applications

    Directory of Open Access Journals (Sweden)

    Ishwar B. Bajaj

    2007-01-01

    Full Text Available The microbial exopolysaccharides are water-soluble polymers secreted by microorganisms during fermentation. The biopolymer gellan gum is a relatively recent addition to the family of microbial polysaccharides that is gaining much importance in food, pharmaceutical and chemical industries due to its novel properties. It is commercially produced by C. P. Kelco in Japan and the USA. Further research and development in biopolymer technology is expected to expand its use. This article presents a critical review of the available information on the gellan gum synthesized by Sphingomonas paucimobilis with special emphasis on its fermentative production and downstream processing. Rheological behaviour of fermentation broth during fermentative production of gellan gum and problems associated with mass transfer have been addressed. Information on the biosynthetic pathway of gellan gum, enzymes and precursors involved in gellan gum production and application of metabolic engineering for enhancement of yield of gellan gum has been specified. Characteristics of gellan gum with respect to its structure, physicochemical properties, rheology of its solutions and gel formation behaviour are discussed. An attempt has also been made to review the current and potential applications of gellan gum in food, pharmaceutical and other industries.

  1. Glomerular prostaglandins modulate vascular reactivity of the downstream efferent arterioles.

    Science.gov (United States)

    Arima, S; Ren, Y; Juncos, L A; Carretero, O A; Ito, S

    1994-03-01

    The balance of vascular resistance in afferent (Af-) and efferent arterioles (Ef-Arts) is a crucial factor that determines glomerular hemodynamics. We have recently reported that when Ef-Arts were perfused from the distal end of the Af-Art through the glomerulus (orthograde perfusion; OP), both angiotensin II (Ang II) and norepinephrine (NE) induced much weaker constriction than they did when Ef-Arts were perfused from the distal end (retrograde perfusion; RP). This difference was not affected by inhibiting synthesis of nitric oxide. In the present study, we tested the hypothesis that glomerular prostaglandins (PGs) may modulate vascular reactivity of the downstream Ef-Art. In addition, we examined the possible modulatory role of PGs in the Af-Art responses to Ang II or NE. Both Ang II and NE caused dose-dependent constriction of Ef-Arts with either OP or RP; however, the constriction was stronger in RP. At 10(-8) M, Ang II decreased Ef-Art diameter by 35 +/- 3.5% in OP (N = 9) compared to 73 +/- 3.9% in RP (N = 5), while 10(-6) M NE decreased the diameter by 25 +/- 3.6% in OP (N = 9) compared to 62 +/- 7.2% in RP (N = 5). Pretreatment with 5 x 10(-5) M indomethacin (Indo) did not alter basal diameter with either method of perfusion.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. Flume experiments on scour downstream of wood stream restoration structures

    Science.gov (United States)

    Pagliara, Stefano; Kurdistani, Sahameddin Mahmoudi

    2017-02-01

    River restoration aims to improve physical natural form and processes of a river. Techniques to control the riverbed, stabilize channel alignment, protect stream banks, and rebuild the natural habitat are an important part of river restoration projects. Rivers can be stabilized and habitat restored through techniques such as rebuilding meanders and pool-riffle sequences and managing large wood. Structures that limit channel width to accelerate the normal flows through the constricted section are referred to as stream deflectors. Single-wing, double-wing and triangular deflectors are the most commonly used types of this measure. Log-frame deflectors consist of a triangular log frame filled with rock. Deflector constructions singly or in series in low gradient meandering streams, divert base flows toward the center of the channel and, under certain conditions, increase the depth and velocity of flow thereby creating scour pools and enhancing fish habitat. Scour characteristics and morphologies downstream of log-frame deflectors have been analyzed at the hydraulic laboratory of the University of Pisa. All experiments have been carried out in clear water conditions. The results showed that the tailwater depth plays an important role on scour characteristics. In addition, it was experimentally proven that using log-frame deflectors instead of log-deflectors result in a better river bank protection. In this case, for all the tested hydraulic conditions, the scour hole never occurred close to the channel bank. Useful empirical relationships have been proposed in order to evaluate the main features of the scour geometry.

  3. Incidental potable water reuse in a Catalonian basin: living downstream

    Directory of Open Access Journals (Sweden)

    R. Mujeriego

    2017-09-01

    Full Text Available A preliminary assessment of incidental potable water reuse (IPR in the Llobregat River basin has been conducted by estimating the dilution factor of treated effluent discharges upstream of six river flow measurement sections. IPR in the Llobregat River basin is an everyday occurrence, because of the systematic discharge of treated effluents upstream of river sections used as drinking water sources. Average river flows at the Sant Joan Despí measurement section increased from 400,000 m3/d (2007 to 864,000 m3/d (2008 and to 931,000 m3/d (2013, while treated effluent discharges upstream of that section ranged from 109,000 m3/d to 114,000 m3/d in those years. The highest degree of IPR occurs downstream of the Abrera and Sant Joan Despí flow measurement sections, from where about half of the drinking water supplied to the Barcelona Metropolitan Area is abstracted. Based on average annual flows, the likelihood that drinking water produced from that river stretch contained treated effluent varied from 25% (2007 to 13% (2008 and to 12% (2013. Water agencies and drinking water production utilities have strived for decades to ensure that drinking water production satisfies applicable quality requirements and provides the required public health protection.

  4. Downstream Processing, Formulation Development and Antithrombotic Evaluation of Microbial Nattokinase.

    Science.gov (United States)

    Kapoor, Rohit; Harde, Harshad; Jain, Sanyog; Panda, Amulya Kumar; Panda, Bibhu Prasad

    2015-07-01

    The present research work describes the downstreaming of nattokinase (NK) produced by Bacillus subtilis under solid state fermentation; and the role of efficient oral formulation of purified NK in the management of thrombotic disorders. Molecular weight of purified NK was estimated to be 28 kDa with specific activity of 504.4 FU/mg. Acid stable nattokinase loaded chitosan nanoparticles (sNLCN) were fabricated for oral delivery of this enzyme. Box-Behnken design (BBD) was employed to investigate and validate the effect of process (independent) variables on the quality attributes (dependent variables) of nanoparticles. The integrity, conformational stability and preservation of fibrinolytic activity of NK (in both free and sNLCN forms) were established by SDS-PAGE, CD analysis and in vitro clot lytic examination, respectively. A 'tail thrombosis model' demonstrated significant decrease in frequency of thrombosis in Wistar rats upon peroral administration of sNLCN in comparison with negative control and free NK group. Furthermore, coagulation analysis, namely the measurement of prothrombin and activated partial thromboplastin time illustrated that sNLCN showed significantly (p < 0.001) higher anti-thrombotic potential in comparison to the free NK. Further, sNLCN showed anti-thrombotic profile similar to warfarin. This study signifies the potential of sNLCN in oral delivery of NK for the management of thrombotic disorders.

  5. Movement patterns of seaward migrating European eel (Anguilla anguilla) at a complex of riverine barriers: implications for conservation

    DEFF Research Database (Denmark)

    Piper, Adam T.; Svendsen, Jon Christian; Wright, Rosalind M.

    2017-01-01

    , this is currently lacking for many species. Employing high-resolution positioning telemetry, this study examined movements of downstream migrating adult European eel, Anguilla anguilla, as they encountered a complex of water control structures in one location on the River Stour, southern England. The distribution...

  6. Network migration for printers

    CERN Multimedia

    2016-01-01

    Further to the recent General Purpose (office) Network reorganisation (as announced in the Bulletin - see here), please note that the majority of print devices will be automatically migrated to the new network IP address range on Tuesday 27 September.   This change should be transparent for these devices and therefore end-users, provided you have installed the printers from the Print Service website. A small number of devices will require manual intervention from the Printer Support team in order to migrate correctly. These devices will not change their IP address until the manual intervention, which will be carried out before Monday 3rd October. However, if you have mistakenly connected directly to the printer’s IP address, then your printing will be affected – please uninstall the printer (for help, see: KB3785), and re-install it from the Print Service website (or follow instructions for visitor machines). Please do this as soon as possible in order to avoid printing issues, t...

  7. Distribution and migration chronology of Eastern population sandhill cranes

    Science.gov (United States)

    Fronczak, David L.; Andersen, David; Hanna, Everett E.; Cooper, Thomas R.

    2017-01-01

    The Eastern Population (EP) of greater sandhill cranes (Antigone canadensis tabida; cranes) is expanding in size and geographic range. Little information exists regarding the geographic extent of breeding, migration, and wintering ranges, migration chronology, or use of staging areas for cranes in the EP. To obtain these data, we attached solar global positioning system (GPS) platform transmitting terminals (PTTs) to 42 sandhill cranes and monitored daily locations from December 2009 through August 2014. On average, tagged cranes settled in summer areas during late‐March in Minnesota (7%), Wisconsin (29%), Michigan, USA (21%), and Ontario, Canada (38%) and arrived at their winter terminus beginning mid‐December in Indiana (15%), Kentucky (3%), Tennessee (45%), Georgia (5%), and Florida (32%). Cranes initiated spring migration beginning mid‐February to their respective summer areas on routes similar to those used during fall migration. Twenty‐five marked cranes returned to the same summer area after a second spring migration, of which 19 (76%) settled cranes in the EP, we estimated that approximately 29–31% of cranes that summered in both Wisconsin and the Lower Peninsula of Michigan were not in areas included in the survey. The information we collected on crane movements provides insight into distribution and migration chronology that will aid in assessment of the current USFWS fall survey. In addition, information on specific use sites can assist state and federal managers to identify and protect key staging and winter areas particularly during current and future recreational harvest seasons.

  8. MIGRATION AND ITS ENVIROMENTAL EFFECTS

    OpenAIRE

    Rashid SAEED; Rana NADIR IDREES; Humna IJAZ; Marriam FURQANI; Raziya NADEEM

    2012-01-01

    Migration can be ongoing shifting of a particular person from one location to another. The reason of shifting depends on selected thought deficiency, shock, difficulties, hopes, enthusiasm. Case study ended up recognizing the extent to which in turn migration can be relying on the specifics especially natural environment. This particular document expects to research the actual linkages between the atmosphere as well as migration using secondary data. Lots of investigation may be completed wit...

  9. Nordic Migration and Integration Research

    OpenAIRE

    Pyrhönen, Niko; Martikainen, Tuomas; Leinonen, Johanna

    2017-01-01

    EXECUTIVE SUMMARY Migration and integration are currently highly contentious topics in political, public and scientific arenas, and will remain so in the near future. However, many common migration-related prejudices and inefficien¬cies in the integration of the migrant population are due to the lack of sound, tested and accessible scientific research. Therefore, the study of migration – by developing basic research and by properly resourcing novel methodological approaches and interventions ...

  10. The challenges of managing migration

    Energy Technology Data Exchange (ETDEWEB)

    Tacoli, Cecilia

    2005-10-15

    Migration and urbanisation are driven by economic growth and social change, but also by deepening inequalities. Managing migration should not be equated with curbing it, as this inevitably reduces migrants' rights. But managing population movement whilst respecting the rights of migrants and nonmigrants, supporting the contribution of migration to poverty reduction and economic growth in sending and receiving areas and reducing the human and material costs of movement means that fundamental challenges need to be addressed.

  11. Preliminary assessment of aggradation potential in the North Fork Stillaguamish River downstream of the State Route 530 landslide near Oso, Washington

    Science.gov (United States)

    Magirl, Christopher S.; Keith, Mackenzie K.; Anderson, Scott W.; O'Connor, Jim; Robert Aldrich,; Mastin, Mark C.

    2015-12-28

    On March 22, 2014, the State Route 530 Landslide near Oso, Washington, traveled almost 2 kilometers (km), destroyed more than 40 structures, and impounded the North Fork Stillaguamish River to a depth of 8 meters (m) and volume of 3.3×106 cubic meters (m3). The landslide killed 43 people. After overtopping and establishing a new channel through the landslide, the river incised into the landslide deposit over the course of 10 weeks draining the impoundment lake and mobilizing an estimated 280,000±56,000 m3 of predominantly sand-sized and finer sediment. During the first 4 weeks after the landslide, this eroded sediment caused downstream riverbed aggradation of 1–2 m within 1 km of the landslide and 0.4 m aggradation at Whitman Road Bridge, 3.5 km downstream. Winter high flows in 2014–15 were anticipated to mobilize an additional 220,000±44,000 m3 of sediment, potentially causing additional aggradation and exacerbating flood risk downstream of the landslide. Analysis of unit stream power and bed-material transport capacity along 35 km of the river corridor indicated that most fine-grained sediment will transport out of the North Fork Stillaguamish River, although some localized additional aggradation was possible. This new aggradation was not likely to exceed 0.1 m except in reaches within a few kilometers downstream of the landslide, where additional aggradation of up to 0.5 m is possible. Alternative river response scenarios, including continued mass wasting from the landslide scarp, major channel migration or avulsion, or the formation of large downstream wood jams, although unlikely, could result in reaches of significant local aggradation or channel change.

  12. Wind-Driven Ecological Flow Regimes Downstream from Hydropower Dams

    Science.gov (United States)

    Kern, J.; Characklis, G. W.

    2012-12-01

    Conventional hydropower can be turned on and off quicker and less expensively than thermal generation (coal, nuclear, or natural gas). These advantages enable hydropower utilities to respond to rapid fluctuations in energy supply and demand. More recently, a growing renewable energy sector has underlined the need for flexible generation capacity that can complement intermittent renewable resources such as wind power. While wind power entails lower variable costs than other types of generation, incorporating it into electric power systems can be problematic. Due to variable and unpredictable wind speeds, wind power is difficult to schedule and must be used when available. As a result, integrating large amounts of wind power into the grid may result in atypical, swiftly changing demand patterns for other forms of generation, placing a premium on sources that can be rapidly ramped up and down. Moreover, uncertainty in wind power forecasts will stipulate increased levels of 'reserve' generation capacity that can respond quickly if real-time wind supply is less than expected. These changes could create new hourly price dynamics for energy and reserves, altering the short-term financial signals that hydroelectric dam operators use to schedule water releases. Traditionally, hourly stream flow patterns below hydropower dams have corresponded in a very predictable manner to electricity demand, whose primary factors are weather (hourly temperature) and economic activity (workday hours). Wind power integration has the potential to yield more variable, less predictable flows at hydro dams, flows that at times could resemble reciprocal wind patterns. An existing body of research explores the impacts of standard, demand-following hydroelectric dams on downstream ecological flows; but weighing the benefits of increased reliance on wind power against further impacts to ecological flows may be a novel challenge for the environmental community. As a preliminary step in meeting this

  13. EUROPEAN UNION INITIATIVES IN TACKLING MIGRATION AND ORGANIZED CRIME AT ITS NEW EASTERN BORDER

    Directory of Open Access Journals (Sweden)

    Adrian Pop

    2008-04-01

    Full Text Available The EU migration strategy in relation to its new eastern neighbours has started to take shape. Among other things, it includes: applying the Global Approach to Migration to the eastern regions neighbouring the EU; securing the necessary funding for migration management through the European Neighbourhood and Partnership Instrument (ENPI and the Thematic Programme for the cooperation with third countries in the areas of migration and asylum; promoting mobility partnerships and circular migration; concluding short-term visa facilitation and readmission agreements; and opening the first Common Visa Application Centre in the capital city of the Republic of Moldova. In addition, the EU has improved its regional focus by the help of the Black Sea Synergy European Commission Communication and extended for 2008-2009 the mandate of its Border Assistance Mission to Moldova and Ukraine (EUBAM, which is set to tackling irregular migration, drugs and cigarettes smuggling, and stolen cars and guns trafficking.

  14. Downstream impacts of dams: shifts in benthic invertivorous fish assemblages

    Science.gov (United States)

    Granzotti, Rafaela Vendrametto; Miranda, Leandro E.; Agostinho, Angelo A.; Gomes, Luiz Carlos

    2018-01-01

    Impoundments alter connectivity, sediment transport and water discharge in rivers and floodplains, affecting recruitment, habitat and resource availability for fish including benthic invertivorous fish, which represent an important link between primary producers and higher trophic levels in tropical aquatic ecosystems. We investigated long-term changes to water regime, water quality, and invertivorous fish assemblages pre and post impoundment in three rivers downstream of Porto Primavera Reservoir in south Brazil: Paraná, Baía and Ivinhema rivers. Impacts were distinct in the Paraná River, which is fully obstructed by the dam, less evident in the Baía River which is partially obstructed by the dam, but absent in the unimpounded Ivinhema River. Changes in water regime were reflected mainly as changes in water-level fluctuation with little effect on timing. Water transparency increased in the Paraná River post impoundment but did not change in the Baía and Ivinhema rivers. Changes in fish assemblages included a decrease in benthic invertivorous fish in the Paraná River and a shift in invertivorous fish assemblage structure in the Baía and Paraná rivers but not in the unimpounded Ivinhema River. Changes in water regime and water transparency, caused by impoundment, directly or indirectly impacted invertivorous fish assemblages. Alterations of fish assemblages following environmental changes have consequences over the entire ecosystem, including a potential decrease in the diversity of mechanisms for energy flow. We suggest that keeping existing unimpounded tributaries free of dams, engineering artificial floods, and intensive management of fish habitat within the floodplain may preserve native fish assemblages and help maintain functionality and ecosystem services in highly impounded rivers.

  15. Low cost energy in Canada: The view from downstream

    International Nuclear Information System (INIS)

    Irving, K.

    1993-01-01

    The key cost determinants of energy in Canada are analyzed and recommendations are made to ensure the competitiveness of Canadian energy costs and energy-consuming industries in the North American and world markets. Oil supplies 45% of world energy and has a key role in determining prices of all other energy forms since it serves as an incremental source of energy: its consumption changes according to economic growth, changes in weather patterns, and other factors. North America currently accounts for about a third of world oil consumption. North American oil demand is expected to remain flat over the next few decades. As Canada only produces ca 3% of world oil supply, it cannot determine oil prices. However, with an efficient downstream industry, Canada can influence the end-user price of energy. The cost structure of refined products in Canada is analyzed. The cost of raw materials is the single biggest determinant of the final product cost, followed by taxes, operating costs, and profit margin. For gasoline in Ontario, taxes account for half the retail cost, crude oil prices ca 30%, and refining costs ca 4%. Refining costs comprise about two thirds labor costs and one third energy costs. Refiner margins have not exceeded 2 cents/l since 1981, creating reluctance to invest in the refining sector. By 1994, some 200,000 bbl/d of refining capacity is expected to be shut down in Canada. Compared to refineries in the USA, Canadian refineries are smaller and have a much lower capacity to upgrade residual fuel oil to light products. Future challenges to the industry include a projected need for $5 billion in investment, largely to fund new environmental initiatives. Such an investment cannot be met through current industry profits. 12 figs., 3 tabs

  16. Downstream fish passage guide walls: A hydraulic scale model analysis

    Science.gov (United States)

    Mulligan, Kevin; Towler, Brett; Haro, Alexander J.; Ahlfeld, David P.

    2018-01-01

    Partial-depth guide walls are used to improve passage efficiency and reduce the delay of out-migrating anadromous fish species by guiding fish to a bypass route (i.e. weir, pipe, sluice gate) that circumvents the turbine intakes, where survival is usually lower. Evaluation and monitoring studies, however, indicate a high propensity for some fish to pass underneath, rather than along, the guide walls, compromising their effectiveness. In the present study we evaluated a range of guide wall structures to identify where/if the flow field shifts from sweeping (i.e. flow direction primarily along the wall and towards the bypass) to downward-dominant. Many migratory fish species, particularly juveniles, are known to drift with the flow and/or exhibit rheotactic behaviour during their migration. When these behaviours are present, fish follow the path of the flow field. Hence, maintaining a strong sweeping velocity in relation to the downward velocity along a guide wall is essential to successful fish guidance. Nine experiments were conducted to measure the three-dimensional velocity components upstream of a scale model guide wall set at a wide range of depths and angles to flow. Results demonstrated how each guide wall configuration affected the three-dimensional velocity components, and hence the downward and sweeping velocity, along the full length of the guide wall. In general, the velocities produced in the scale model were sweeping dominant near the water surface and either downward dominant or close to the transitional depth near the bottom of the guide wall. The primary exception to this shift from sweeping do downward flow was for the minimum guide wall angle tested in this study (15°). At 15° the flow pattern was fully sweeping dominant for every cross-section, indicating that a guide wall with a relatively small angle may be more likely to produce conditions favorable to efficient guidance. A critical next step is to evaluate the behaviour of migratory fish as

  17. Countering inbreeding with migration 1. Migration from unrelated ...

    African Journals Online (AJOL)

    Ret:ieved 6 Octoher 1991; ut:cepted I8 Mur- 1995. The eff'ect of migration on inbreeding is moclelled fbr small populations with immigrants from a large unrelated population. Different migration rates and numbers fbr the two sexes are assumed, and a general recursion equation for inbreeding progress derived, which can ...

  18. Migration and regional inequality

    DEFF Research Database (Denmark)

    Peng, Lianqing; Swider, Sarah

    2017-01-01

    Scholars studying economic inequality in China have maintained that regional inequality and economic divergence across provinces have steadily increased over the past 30 years. New studies have shown that this trend is a statistical aberration; calculations show that instead of quickly and sharply...... rising, regional inequality has actually decreased, and most recently, remained stable. Our study suggests that China’s unique migratory regime is crucial to understanding these findings. We conduct a counterfactual simulation to demonstrate how migration and remittances have mitigated income inequality...... across provinces in order to show that without these processes, we would have seen more of a rise in interprovincial income inequality. We conclude by arguing that inequality in China is still increasing, but it is changing and becoming less place-based. As regional inequality decreases, there are signs...

  19. Tracking migrating birds

    DEFF Research Database (Denmark)

    Willemoes, Mikkel

    habitats with those in rural habitats. Some species have decreased the frequency of migrants and migration distance in urban environments, and others have not. The other manuscript describes the small scale movements of three different Palaearctic migrants during winter in Africa in a farmland habitat....... In another species, environmental conditions are not a good predictor of movements, and possibly effects of timing constraints or food type play a role. Two manuscripts focus on the effects of human-induced habitat alterations on migratory behaviour. One compares the movements of partial migrants in urban...... and a forest reserve. In the degraded habitat all species used more space, although the consequence on bird density is less clear. Two manuscripts relate the migratory movements of a long-distance migrant with models of navigation. One compares model predictions obtained by simulation with actual movements...

  20. Making Migration Meaningful

    DEFF Research Database (Denmark)

    Benwell, Ann Fenger

    2013-01-01

    a way to escape family patriarchy and conformity, and can contribute to loss, hardship, and uncertainty for family members left behind. Further, mobility provides opportunities and a means to escape the stigma of ‘laziness’ culturally associated with poverty and immobility. Postsocialist separation has...... of absence by migrant family members, as both men and women are culturally permitted to be separate from their families. Migration is understood to contribute to prosperity, and separations contribute to generate growth and hishig (good fortune) for the good of the family. However, such mobility is also......Mongolia has experienced two decades since the demise of the Soviet Union and has implemented strategies to strengthen its economy and its democratic practices. Transitions from being a nomadic society to a Soviet satellite state and onwards to liberal democracy have greatly impacted family life...

  1. Nightly Test system migration

    CERN Document Server

    Win-Lime, Kevin

    2013-01-01

    The summer student program allows students to participate to the Cern adventure. They can follow several interesting lectures about particle science and participate to the experiment work. As a summer student, I had worked for LHCb experiment. LHCb uses a lot of software to analyze its data. All this software is organized in packages and projects. They are built and tested during the night using an automated system and the results are displayed on a web interface. Actually, LHCb is changing this system. It is looking for a replacement candidate. So I was charged to unify some internal interfaces to permit a swift migration. In this document, I will describe shortly the system used by LHCb, then I will explain what I have done in detail.

  2. Downstream processing and chromatography based analytical methods for production of vaccines, gene therapy vectors, and bacteriophages

    Science.gov (United States)

    Kramberger, Petra; Urbas, Lidija; Štrancar, Aleš

    2015-01-01

    Downstream processing of nanoplexes (viruses, virus-like particles, bacteriophages) is characterized by complexity of the starting material, number of purification methods to choose from, regulations that are setting the frame for the final product and analytical methods for upstream and downstream monitoring. This review gives an overview on the nanoplex downstream challenges and chromatography based analytical methods for efficient monitoring of the nanoplex production. PMID:25751122

  3. Migration: the trends converge.

    Science.gov (United States)

    1985-09-01

    Formerly, Australia, New Zealand, Canada, and the US have served as permanent destinations for immigrants, while Europe's migrants have moved to more northerly countries to work for a time and then returned home. From 1973-1975 Europe's recruitment of foreign workers virtually ended, although family reunion for those immigrants allowed in was encouraged. Problems resulting from this new settlement migration include low paying jobs for immigrant women, high unemployment, and inadequate education for immigrant children. Illegal migrants from Latin America and the Caribbean enter the US and Canada each year while illegal North African immigrants enter Italy, Spain, and Greece. North America, Australia, and Europe have all received political refugees from Asia and Latin America. Increasingly, these foreigners compete in the labor market rather than simply fill jobs the native workers do not want. All the receiving countries have similar policy priorities: 1) more effective ways for controlling and monitoring inflows and checking illegal immigration; 2) encouraging normal living patterns and accepting refugees; and 3) integrating permanent migrants into the host country. Europe's public immigration encouragement prior to the first oil shock, has left some countries with a labor force that is reluctant to return home. It is unlikely that Europe will welcome foreign labor again in this decade, since unemployment among young people and women is high and family reunion programs may still bring in many immigrants. Less immigration pattern change will probably occur in North America, Australia, and New Zealand since these countries' populations are still growing and wages are more flexible. Immigration, regulated by policy, and emigration, determined by market forces, now are working in the same direction and will likely reduce future migration flows.

  4. Migration and spawning of female surubim (Pseudoplatystoma corruscans, Pimelodidae) in the São Francisco river, Brazil

    Science.gov (United States)

    Godinho, Alexandre L.; Kynard, Boyd; Godinho, Hugo P.

    2007-01-01

    Surubim, Pseudoplatystoma corruscans, is the most valuable commercial and recreational fish in the São Francisco River, but little is known about adult migration and spawning. Movements of 24 females (9.5–29.0 kg), which were radio-tagged just downstream of Três Marias Dam (TMD) at river kilometer 2,109 and at Pirapora Rapids (PR) 129 km downstream of TMD, suggest the following conceptual model of adult female migration and spawning. The tagged surubims used only 274 km of the main stem downstream of TMD and two tributaries, the Velhas and Abaeté rivers. Migration style was dualistic with non-migratory (resident) and migratory fish. Pre-spawning females swam at ground speeds of up to 31 km day-1 in late September–December to pre-spawning staging sites located 0–11 km from the spawning ground. In the spawning season (November–March), pre-spawning females migrated back and forth from nearby pre-spawning staging sites to PR for short visits to spawn, mostly during floods. Multiple visits to the spawning site suggest surubim is a multiple spawner. Most post-spawning surubims left the spawning ground to forage elsewhere, but some stayed at the spawning site until the next spawning season. Post-spawning migrants swam up or downstream at ground speeds up to 29 km day-1 during January–March. Construction of proposed dams in the main stem and tributaries downstream of TMD will greatly reduce surubim abundance by blocking migrations and changing the river into reservoirs that eliminate riverine spawning and non-spawning habitats, and possibly, cause extirpation of populations.

  5. Challenged by migration: Europe's options

    NARCIS (Netherlands)

    Constant, Amelie F.; Zimmermann, Klaus F.

    2017-01-01

    This paper examines the migration and labour mobility in the European Union and elaborates on their importance for the existence of the EU. Against all measures of success, the current public debate seems to suggest that the political consensus that migration is beneficial is broken. This comes with

  6. Radionuclide migration studies in soil

    International Nuclear Information System (INIS)

    Marumo, J.T.

    1989-01-01

    In this work a brief description about retention and migration parameters of radionuclides in soil, including main methods to determine the distribution coefficient (K) are given. Some of several factors that can act on the migration are also mentioned. (author) [pt

  7. South-South Migration and Remittances

    OpenAIRE

    Ratha, Dilip; Shaw, William

    2007-01-01

    South-South Migration and Remittances reports on preliminary results from an ongoing effort to improve data on bilateral migration stocks. It sets out some working hypotheses on the determinants and socioeconomic implications of South-South migration. Contrary to popular perception that migration is mostly a South-North phenomenon, South-South migration is large. Available data from nation...

  8. Repriming by PrimPol is critical for DNA replication restart downstream of lesions and chain-terminating nucleosides.

    Science.gov (United States)

    Kobayashi, Kaori; Guilliam, Thomas A; Tsuda, Masataka; Yamamoto, Junpei; Bailey, Laura J; Iwai, Shigenori; Takeda, Shunichi; Doherty, Aidan J; Hirota, Kouji

    2016-08-02

    PrimPol is a DNA damage tolerance enzyme possessing both translesion synthesis (TLS) and primase activities. To uncover its potential role in TLS-mediated IgVλ hypermutation and define its interplay with other TLS polymerases, PrimPol(-/-) and PrimPol(-/-)/Polη(-/-)/Polζ (-/-) gene knockouts were generated in avian cells. Loss of PrimPol had no significant impact on the rate of hypermutation or the mutation spectrum of IgVλ. However, PrimPol(-/-) cells were sensitive to methylmethane sulfonate, suggesting that it may bypass abasic sites at the IgVλ segment by repriming DNA synthesis downstream of these sites. PrimPol(-/-) cells were also sensitive to cisplatin and hydroxyurea, indicating that it assists in maintaining / restarting replication at a variety of lesions. To accurately measure the relative contribution of the TLS and primase activities, we examined DNA damage sensitivity in PrimPol(-/-) cells complemented with polymerase or primase-deficient PrimPol. Polymerase-defective, but not primase-deficient, PrimPol suppresses the hypersensitivity of PrimPol(-/-) cells. This indicates that its primase, rather than TLS activity, is pivotal for DNA damage tolerance. Loss of TLS polymerases, Polη and Polζ has an additive effect on the sensitivity of PrimPol(-/-) cells. Moreover, we found that PrimPol and Polη-Polζ redundantly prevented cell death and facilitated unperturbed cell cycle progression. PrimPol(-/-) cells also exhibited increased sensitivity to a wide variety of chain-terminating nucleoside analogs (CTNAs). PrimPol could perform close-coupled repriming downstream of CTNAs and oxidative damage in vitro. Together, these results indicate that PrimPol's repriming activity plays a central role in reinitiating replication downstream from CTNAs and other specific DNA lesions.

  9. Measuring International Migration in Azerbaijan

    Directory of Open Access Journals (Sweden)

    Serhat Yüksel

    2018-01-01

    Full Text Available International migration significantly affects economic, social, cultural, and political factors of the country. Owing to this situation, it can be said that the reasons of international migration should be analyzed in order to control this problem. The purpose of this study is to determine the influencing factors of international migration in Azerbaijan. In this scope, annual data of 11 explanatory variables for the period of 1995–2015 was analyzed via Multivariate Adaptive Regression Splines (MARS method. According to the results of this analysis, it was identified that people prefer to move other countries in case of high unemployment rates. In addition, the results of the study show that population growth and high mortality rate increases the migration level. While considering these results, it was recommended that Azerbaijan should focus on these aspects to control international migration problem.

  10. Wages, Welfare Benefits and Migration.

    Science.gov (United States)

    Kennan, John; Walker, James R

    2010-05-01

    Differences in economic opportunities give rise to strong migration incentives, across regions within countries, and across countries. In this paper we focus on responses to differences in welfare benefits across States. We apply the model developed in Kennan and Walker (2008), which emphasizes that migration decisions are often reversed, and that many alternative locations must be considered. We model individual decisions to migrate as a job search problem. A worker starts the life-cycle in some home location and must determine the optimal sequence of moves before settling down. The model is sparsely parameterized. We estimate the model using data from the National Longitudinal Survey of Youth (1979). Our main finding is that income differences do help explain the migration decisions of young welfare-eligible women, but large differences in benefit levels provide surprisingly weak migration incentives.

  11. Migration of radionuclides through a river system

    Energy Technology Data Exchange (ETDEWEB)

    Matsunaga, Takeshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1999-03-01

    Migration behavior of several atmospherically-derived radionuclides in a river watershed was studied. A main interest was in their relocation from the ground soil of the watershed to a downstream region through a river. Studied radionuclides are: {sup 137}Cs generated by weapon tests in the atmosphere; {sup 210}Pb and {sup 7}Be of naturally occurring radionuclides; {sup 137}Cs, {sup 90}Sr, {sup 239,240}Pu and {sup 241}Am released by the Chernobyl nuclear power plant accident. Dominance of the form in suspended solid in river water (particulate form) was qualified for the radionuclides in the Kuji river watershed. An importance of discharge in flooding was also confirmed. A historical budget analysis for weapon test derived {sup 137}Cs was presented for the Hi-i river watershed and its accompanied lake sediment (Lake Shinji). The work afforded a scheme of a fate of {sup 137}Cs after falling on the ground soil and on the lake surface. Several controlling factors, which can influence on the chemical form of radionuclides discharged to a river, were also investigated in the vicinity of the Chernobyl nuclear power plant. A special attention was paid on the association of the radionuclides with dissolved species in water. Preferential association of Pu and Am isotopes to a large molecular size of dissolved matrices, probably of humic substances, was suggested. (author)

  12. Migrating and herniating hydatid cysts

    International Nuclear Information System (INIS)

    Koc, Zafer; Ezer, Ali

    2008-01-01

    Objective: To present the prevalence and imaging findings of patients with hydatid disease (HD) showing features of migration or herniation of the hydatid cysts (HCs) and underline the clinical significance of this condition. Materials and methods: Between May 2003 and June 2006, 212 patients with HD were diagnosed by abdomen and/or thorax CT, searched for migrating or herniating HC. Imaging findings of 7 patients (5 women, 2 men with an age range of 19-63 years; mean ± S.D., 44 ± 19 years) with HD showing transdiaphragmatic migration (6 subjects) or femoral herniation (1 subject) were evaluated. Diagnosis of all the patients were established by pathologic examination and migration or herniation was confirmed by surgery in all patients. Results: Liver HD were identified in 169 (79.7%) of 212 patients with HD. Transdiaphragmatic migration of HCs were identified in 6 (3.5%) of the 169 patients with liver HD. In one patient, femoral herniation of the retroperitoneal HC into the proximal anterior thigh was identified. All of these seven patients exhibiting migration or herniation of HCs had active HCs including 'daughter cysts'. Two patients had previous surgery because of liver HD and any supradiaphragmatic lesion was not noted before operation. Findings of migration or herniation were confirmed by surgery. Conclusion: Active HCs may show migration or herniation due to pressure difference between the anatomic cavities, and in some of the patients, by contribution of gravity. Previous surgery may be a complementary factor for migration as seen in two of our patients. The possibility of migration or herniation in patients with HD should be considered before surgery

  13. Current Migration Movements in Europe

    Directory of Open Access Journals (Sweden)

    Jelena Zlatković Winter

    2004-09-01

    Full Text Available After a brief historical review of migrations in Europe, the paper focuses on current migration trends and their consequences. At the end of the 1950s, Western Europe began to recruit labour from several Mediterranean countries – Italy, Spain, Portugal and former Yugoslavia, and later from Morocco, Algeria, Tunisia and Turkey. Some countries, such as France, Great Britain and the Netherlands, recruited also workers from their former colonies. In 1970 Germany had the highest absolute number of foreigners, followed by France, and then Switzerland and Belgium. The total number of immigrants in Western Europe was twelve million. During the 1970s mass recruitment of foreign workers was abandoned, and only the arrival of their family members was permitted, which led to family reunification in the countries of employment. Europe closed its borders, with the result that clandestine migration increased. The year 1989 was a turning point in the history of international migrations. The political changes in Central and Eastern Europe brought about mass migration to the West, which culminated in the so-called “mass movement of 1989–1990”. The arrival of ethnic Germans in Germany, migration inside and outside of the territory of the former Soviet Union, an increase in the number of asylum seekers and displaced persons, due to armed conflicts, are – according to the author – the main traits of current migration. The main part of the paper discusses the causes and effects of this mass wave, as well as trends in labour migration, which is still present. The second part of the paper, after presenting a typology of migrations, deals with the complex processes that brought about the formation of new communities and led to the phenomenon of new ethnic minorities and to corresponding migration policies in Western European countries that had to address these issues.

  14. Glycerol-3-phosphate Acyltransferase 1 Promotes Tumor Cell Migration and Poor Survival in Ovarian Carcinoma.

    Science.gov (United States)

    Marchan, Rosemarie; Büttner, Bettina; Lambert, Jörg; Edlund, Karolina; Glaeser, Iris; Blaszkewicz, Meinolf; Leonhardt, Gregor; Marienhoff, Lisa; Kaszta, Darius; Anft, Moritz; Watzl, Carsten; Madjar, Katrin; Grinberg, Marianna; Rempel, Eugen; Hergenröder, Roland; Selinski, Silvia; Rahnenführer, Jörg; Lesjak, Michaela S; Stewart, Joanna D; Cadenas, Cristina; Hengstler, Jan G

    2017-09-01

    Glycerophosphodiesterase EDI3 (GPCPD1; GDE5; GDPD6) has been suggested to promote cell migration, adhesion, and spreading, but its mechanisms of action remain uncertain. In this study, we targeted the glycerol-3-phosphate acyltransferase GPAM along with choline kinase-α (CHKA), the enzymes that catabolize the products of EDI3 to determine which downstream pathway is relevant for migration. Our results clearly showed that GPAM influenced cell migration via the signaling lipid lysophosphatidic acid (LPA), linking it with GPAM to cell migration. Analysis of GPAM expression in different cancer types revealed a significant association between high GPAM expression and reduced overall survival in ovarian cancer. Silencing GPAM in ovarian cancer cells decreased cell migration and reduced the growth of tumor xenografts. In contrast to these observations, manipulating CHKA did not influence cell migration in the same set of cell lines. Overall, our findings show how GPAM influences intracellular LPA levels to promote cell migration and tumor growth. Cancer Res; 77(17); 4589-601. ©2017 AACR . ©2017 American Association for Cancer Research.

  15. Nonautonomous Regulation of Neuronal Migration by Insulin Signaling, DAF-16/FOXO, and PAK-1

    Directory of Open Access Journals (Sweden)

    Lisa M. Kennedy

    2013-09-01

    Full Text Available Neuronal migration is essential for nervous system development in all organisms and is regulated in the nematode, C. elegans, by signaling pathways that are conserved in humans. Here, we demonstrate that the insulin/IGF-1-PI3K signaling pathway modulates the activity of the DAF-16/FOXO transcription factor to regulate the anterior migrations of the hermaphrodite-specific neurons (HSNs during embryogenesis of C. elegans. When signaling is reduced, DAF-16 is activated and promotes migration; conversely, when signaling is enhanced, DAF-16 is inactivated, and migration is inhibited. We show that DAF-16 acts nonautonomously in the hypodermis to promote HSN migration. Furthermore, we identify PAK-1, a p21-activated kinase, as a downstream mediator of insulin/IGF-1-DAF-16 signaling in the nonautonomous control of HSN migration. Because a FOXO-Pak1 pathway was recently shown to regulate mammalian neuronal polarity, our findings indicate that the roles of FOXO and Pak1 in neuronal migration are most likely conserved from C. elegans to higher organisms.

  16. Non-autonomous Regulation of Neuronal Migration by Insulin Signaling, DAF-16/FOXO and PAK-1

    Science.gov (United States)

    Kennedy, Lisa M.; Pham, Steven C.D.L.; Grishok, Alla

    2013-01-01

    SUMMARY Neuronal migration is essential for nervous system development in all organisms and is regulated in the nematode, C. elegans, by signaling pathways that are conserved in humans. Here, we demonstrate that the Insulin/IGF-1-PI3K signaling pathway modulates the activity of the DAF-16/FOXO transcription factor to promote the anterior migrations of the hermaphrodite-specific neurons (HSNs) during embryogenesis of C. elegans. When signaling is reduced, DAF-16 is activated and promotes migration, conversely, when signaling is enhanced, DAF-16 is inactivated and migration is inhibited. We show that DAF-16 acts non-autonomously in the hypodermis to promote HSN migration. Furthermore, we identify PAK-1, a p21-activated kinase, as a downstream mediator of Insulin/IGF-1-DAF-16 signaling in the non-autonomous control of HSN migration. As a FOXO-Pak1 pathway was recently shown to regulate mammalian neuronal polarity, our findings indicate that the roles of FOXO and Pak1 in neuronal migration are likely conserved from C. elegans to higher organisms. PMID:23994474

  17. Assisted Living

    Science.gov (United States)

    ... a resident's needs depends as much on the philosophy and services of the assisted living facility as it does on the quality of care. The Administration on Aging, a part of the U.S. Department of Health and Human Services (HHS), offers these suggestions to help you ...

  18. Assistive Devices

    Science.gov (United States)

    If you have a disability or injury, you may use a number of assistive devices. These are tools, products or types of equipment that help you perform tasks and activities. They may help you move around, see, communicate, eat, or get ...

  19. Simulating potential structural and operational changes for Detroit Dam on the North Santiam River, Oregon, for downstream temperature management

    Science.gov (United States)

    Buccola, Norman L.; Rounds, Stewart A.; Sullivan, Annett B.; Risley, John C.

    2012-01-01

    Detroit Dam was constructed in 1953 on the North Santiam River in western Oregon and resulted in the formation of Detroit Lake. With a full-pool storage volume of 455,100 acre-feet and a dam height of 463 feet, Detroit Lake is one of the largest and most important reservoirs in the Willamette River basin in terms of power generation, recreation, and water storage and releases. The U.S. Army Corps of Engineers operates Detroit Dam as part of a system of 13 reservoirs in the Willamette Project to meet multiple goals, which include flood-damage protection, power generation, downstream navigation, recreation, and irrigation. A distinct cycle in water temperature occurs in Detroit Lake as spring and summer heating through solar radiation creates a warm layer of water near the surface and isolates cold water below. Controlling the temperature of releases from Detroit Dam, therefore, is highly dependent on the location, characteristics, and usage of the dam's outlet structures. Prior to operational changes in 2007, Detroit Dam had a well-documented effect on downstream water temperature that was problematic for endangered salmonid fish species, releasing water that was too cold in midsummer and too warm in autumn. This unnatural seasonal temperature pattern caused problems in the timing of fish migration, spawning, and emergence. In this study, an existing calibrated 2-dimensional hydrodynamic water-quality model [CE-QUAL-W2] of Detroit Lake was used to determine how changes in dam operation or changes to the structural release points of Detroit Dam might affect downstream water temperatures under a range of historical hydrologic and meteorological conditions. The results from a subset of the Detroit Lake model scenarios then were used as forcing conditions for downstream CE-QUAL-W2 models of Big Cliff Reservoir (the small reregulating reservoir just downstream of Detroit Dam) and the North Santiam and Santiam Rivers. Many combinations of environmental, operational, and

  20. The Impact of Utilising Mobile Assisted Language Learning (MALL) on Vocabulary Acquisition among Migrant Women English Learners

    Science.gov (United States)

    Ahmad, Kham Sila; Armarego, Jocelyn; Sudweeks, Fay

    2017-01-01

    Aim/Purpose: To develop a framework for utilizing Mobile Assisted Language Learning (MALL) to assist non-native English migrant women to acquire English vocabulary in a non-formal learning setting. Background: The women in this study migrated to Australia with varied backgrounds including voluntary or forced migration, very low to high levels of…

  1. Mobilization and attenuation of metals downstream from a base-metal mining site in the Matra Mountains, northeastern Hungary

    Science.gov (United States)

    Odor, L.; Wanty, R.B.; Horvath, I.; Fugedi, U.; ,

    1999-01-01

    Regional geochemical baseline values have been established for Hungary by the use of low-density stream-sediment surveys of flood-plain deposits of large drainage basins and of the fine fraction of stream sediments. The baseline values and anomaly thresholds thus produced helped to evaluate the importance of high toxic element concentrations found in soils in a valley downstream of a polymetallic vein-type base-metal mine. Erosion of the mine dumps and flotation dump, losses of metals during filtering, storage and transportation, human neglects, and operational breakdowns, have all contributed to the contamination of a small catchment basin in a procession of releases of solid waste. The sulfide-rich waste material weathers to a yellow color; this layer of 'yellow sand' blankets a narrow strip of the floodplain of Toka Creek in the valley near the town of Gyongyosoroszi. Contamination was spread out in the valley by floods. Metals present in the yellow sand include Pb, As, Cd, Cu, Zn, and Sb. Exposure of the local population to these metals may occur through inhalation of airborne particulates or by ingestion of these metals that are taken up by crops grown in the valley. To evaluate the areal extent and depth of the contamination, active stream sediment, flood-plain deposits, lake or reservoir sediments, soils, and surface water were sampled along the erosion pathways downstream of the mine and dumps. The flood-plain profile was sampled in detail to see the vertical distribution of elements and to relate the metal concentrations to the sedimentation and contamination histories of the flood plain. Downward migration of mobile Zn and Cd from the contaminated upper layers under supergene conditions is observed, while vertical migration of Pb, As, Hg and Sb appears to be insignificant. Soil profiles of 137Cs which originated from above-ground atomic bomb tests and the Chernobyl accident, provide good evidence that the upper 30-40 cm of the flood-plain sections, which

  2. Geochemistry and radionuclide migration

    International Nuclear Information System (INIS)

    Isherwood, D.

    1978-01-01

    Theoretically, the geochemical barrier can provide a major line of defense in protecting the biosphere from the hazards of nuclear waste. The most likely processes involved are easily identified. Preliminary investigations using computer modeling techniques suggest that retardation is an effective control on radionuclide concentrations. Ion exchange reactions slow radionuclide migration and allow more time for radioactive decay and dispersion. For some radionuclides, solubility alone may limit concentrations to less than the maximum permissible now considered acceptable by the Federal Government. The effectiveness of the geochemical barrier is ultimately related to the repository site characteristics. Theory alone tells us that geochemical controls will be most efficient in an environment that provides for maximum ion exchange and the precipitation of insoluble compounds. In site selection, consideration should be given to rock barriers with high ion exchange capacity that might also act as semi-permeable membranes. Also important in evaluating the site's potential for effective geochemical controls are the oxidation potentials, pH and salinity of the groundwater

  3. NNDC database migration project

    Energy Technology Data Exchange (ETDEWEB)

    Burrows, Thomas W; Dunford, Charles L [U.S. Department of Energy, Brookhaven Science Associates (United States)

    2004-03-01

    NNDC Database Migration was necessary to replace obsolete hardware and software, to be compatible with the industry standard in relational databases (mature software, large base of supporting software for administration and dissemination and replication and synchronization tools) and to improve the user access in terms of interface and speed. The Relational Database Management System (RDBMS) consists of a Sybase Adaptive Server Enterprise (ASE), which is relatively easy to move between different RDB systems (e.g., MySQL, MS SQL-Server, or MS Access), the Structured Query Language (SQL) and administrative tools written in Java. Linux or UNIX platforms can be used. The existing ENSDF datasets are often VERY large and will need to be reworked and both the CRP (adopted) and CRP (Budapest) datasets give elemental cross sections (not relative I{gamma}) in the RI field (so it is not immediately obvious which of the old values has been changed). But primary and secondary intensities are now available on the same scale. The intensity normalization has been done for us. We will gain access to a large volume of data from Budapest and some of those gamma-ray intensity and energy data will be superior to what we already have.

  4. Radionuclide migration in soils

    Energy Technology Data Exchange (ETDEWEB)

    Demir, M [Ingenieurgesellschaft Bonnenberg und Drescher, Juelich (Germany, F.R.)

    1979-01-01

    Unplanned releases from a nuclear installation - e.g., leakage from a storage tank or other incident - can result in the escape of contaminants such as U, Pu, Cs, Sr, T etc. Nuclide transport through the ground is governed by characteristics of the subsurface hydrology and the specific nuclides under consideration. Unsaturated soil layers result in a transport rate so low as to negligible. Radionuclides reaching the ground water are assumed to endanger human life because of potential uncontrolled ingestion. The most dangerous nuclides are long-lived and not absorbed, or very poorly absorbed, in the soil. During migration of nuclides through saturated soil layers, the concentration can be reduced by dilution. Preliminary results indicate that tritium is spread with ground water velocity. Its concentration can be reduced only by diffusion, dispersion and radioactive decay. Alpha-emitters are strongly retained velocities of alpha-emitters are approximately one thousandth (10/sup -3/) that of T. Transport velocities of Cs and Sr are approximately one hundreth (10/sup -2/) and one tenth (10/sup -1/) that of T respectively.

  5. Radionuclide migration in soils

    International Nuclear Information System (INIS)

    Demir, M.

    1979-01-01

    Unplanned releases from a nuclear installation - e.g., leakage from a storage tank or other incident - can result in the escape of contaminants such as U, Pu, Cs, Sr, T etc. Nuclide transport through the ground is governed by characteristics of the subsurface hydrology and the specific nuclides under consideration. Unsaturated soil layers result in a transport rate so low as to negligible. Radionuclides reaching the ground water are assumed to endanger human life because of potential uncontrolled ingestion. The most dangerous nuclides are long-lived and not absorbed, or very poorly absorbed, in the soil. During migration of nuclides through saturated soil layers, the concentration can be reduced by dilution. Preliminary results indicate that tritium is spread with ground water velocity. Its concentration can be reduced only by diffusion, dispersion and radioactive decay. Alpha-emitters are strongly retained velocities of alpha-emitters are approximately one thousandth (10 -3 ) that of T. Transport velocities of Cs and Sr are approximately one hundreth (10 -2 ) and one tenth (10 -1 ) that of T respectively. (orig./HP) [de

  6. Psychosocial Aspects of Migration

    Directory of Open Access Journals (Sweden)

    Ayla Tuzcu

    2014-02-01

    Full Text Available The incident of migration that occurs as a result of the mobility of individuals between various regions and is considered a social change process brings along various factors. Among these factors, the most important one is the culture of the new society where the immigrant begins to live and the process of adaptation with this culture. Individuals from different cultures are required to live together, cope with differences and overcome the difficulties. The process of adaptation to the new lifestyle might cause the individual to have some feelings such as loneliness, socially isolation, being alienated, being regretful and self-depreciation, and consequently experience a greater stress. Being unable to cope with stress efficiently creates risks in individuals in terms of health problems such as anxiety and depression. Healthcare professionals are required to evaluate life styles, difficulties and coping levels of immigrants in order to protect and develop their mental health. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2014; 6(1.000: 56-66

  7. 40 CFR 80.210 - What sulfur standards apply to gasoline downstream from refineries and importers?

    Science.gov (United States)

    2010-07-01

    ... combined with non-S-RGAS for the sole purpose of producing midgrade gasoline. (6) Where S-RGAS is being... of the gasoline. (f) Downstream standards applicable to S-RGAS when produced or imported. (1) The downstream standard applicable to any gasoline classified as S-RGAS when produced or imported shall be...

  8. Hydrodynamic properties and distribution of bait downstream of a zooplankton trap

    DEFF Research Database (Denmark)

    Selander, Erik; Heuschele, Jan; Larsson, Ann I.

    2017-01-01

    The flow regime around a chemically baited trap is crucial for the trapping process and distribution of bait downstream of traps. We measured the flow field downstream of a trap prototype in flume experiments and mapped the distribution of bait using laser induced fluorescence. The trap produced ...

  9. 40 CFR 80.220 - What are the downstream standards for GPA gasoline?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false What are the downstream standards for GPA gasoline? 80.220 Section 80.220 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... downstream location other than at a retail outlet or wholesale purchaser-consumer facility, and during the...

  10. MIGRATION IMPACT ON ECONOMICAL SITUATION

    Directory of Open Access Journals (Sweden)

    Virginia COJOCARU

    2016-01-01

    Full Text Available This paper presents recent trends and flows of labor migration and its impact on economic and social life. Main aim of this research sets up the influence of the migration on the European economics and its competitiveness. Methods of research are: method of comparison, analysis method, method of deduction, method of statistics, modeling method. The economic impact of migration has been intensively studied but is still often driven by ill-informed perceptions, which, in turn, can lead to public antagonism towards migration. These negative views risk jeopardising efforts to adapt migration policies to the new economic and demographic challenges facing many countries. Migration Policy looks at the evidence for how immigrants affect the economy in three main areas: The labour market, public purse and economic growth. In Europe, the scope of labour mobility greatly increased within the EU/EFTA zones following the EU enlargements of 2004, 2007 and 2014-2015. This added to labour markets’ adjustment capacity. Recent estimates suggest that as much as a quarter of the asymmetric labour market shock – that is occurring at different times and with different intensities across countries – may have been absorbed by migration within a year.

  11. Vulnerable to HIV / AIDS. Migration.

    Science.gov (United States)

    Fernandez, I

    1998-01-01

    This special report discusses the impact of globalization, patterns of migration in Southeast Asia, gender issues in migration, the links between migration and HIV/AIDS, and spatial mobility and social networks. Migrants are particularly marginalized in countries that blame migrants for transmission of infectious and communicable diseases and other social ills. Effective control of HIV/AIDS among migrant and native populations requires a multisectoral approach. Programs should critically review the privatization of health care services and challenge economic models that polarize the rich and the poor, men and women, North and South, and migrant and native. Programs should recognize the equality between locals and migrants in receipt of health services. Countermeasures should have input from migrants in order to reduce the conditions that increase vulnerability to HIV/AIDS. Gender-oriented research is needed to understand women's role in migration. Rapid assessment has obscured the human dimension of migrants' vulnerability to HIV. Condom promotion is not enough. Migration is a major consequence of globalization, which holds the promise, real or imagined, of prosperity for all. Mass migration can be fueled by explosive regional developments. In Southeast Asia, migration has been part of the process of economic development. The potential to emigrate increases with greater per capita income. "Tiger" economies have been labor importers. Safe sex is not practiced in many Asian countries because risk is not taken seriously. Migrants tend to be used as economic tools, without consideration of social adjustment and sex behavior among singles.

  12. Income Inequality and Migration in Vietnam

    OpenAIRE

    NGUYEN, Tien Dung

    2012-01-01

    In this paper, we have analyzed the recent trends in income inequality, internal and international migrations and investigated the impact of migration on income distribution in Vietnam. Our analysis shows that the effects of migration on income inequality vary with different types of migration, depending on who migrate and where they migrate. Foreign remittances tend to flow toward more affluent households, and they increase income inequality. By contrast, domestic remittances accrue more to ...

  13. Fluvial wood function downstream of beaver versus man-made dams in headwater streams in Massachusetts, USA

    Science.gov (United States)

    David, G. C.; DeVito, L. F.; Munz, K. T.; Lisius, G.

    2014-12-01

    Fluvial wood is an essential component of stream ecosystems by providing habitat, increasing accumulation of organic matter, and increasing the processing of nutrients and other materials. However, years of channel alterations in Massachusetts have resulted in low wood loads despite the afforestation that has occurred since the early 1900s. Streams have also been impacted by a large density of dams, built during industrialization, and reduction of the beaver population. Beavers were reintroduced to Massachusetts in the 1940s and they have since migrated throughout the state. Beaver dams impound water, which traps sediment and results in the development of complex channel patterns and more ecologically productive and diverse habitats than those found adjacent to man-made dams. To develop better management practices for dam removal it is essential that we understand the geomorphic and ecologic function of wood in these channels and the interconnections with floodplain dynamics and stream water chemistry. We investigate the connections among fluvial wood, channel morphology, floodplain soil moisture dynamics, and stream water chemistry in six watersheds in Massachusetts that have been impacted by either beaver or man-made dams. We hypothesize that wood load will be significantly higher below beaver dams, subsequently altering channel morphology, water chemistry, and floodplain soil moisture. Reaches are surveyed up- and downstream of each type of dam to better understand the impact dams have on the fluvial system. Surveys include a longitudinal profile, paired with dissolved oxygen and ammonium measurements, cross-section and fluvial wood surveys, hydraulic measurements, and floodplain soil moisture mapping. We found that dissolved oxygen mirrored the channel morphology, but did not vary significantly between reaches. Wood loads were significantly larger downstream of beaver dams, which resulted in significant changes to the ammonium levels. Floodplain soil moisture

  14. Migration of the Duraloc cup after 5 years.

    Science.gov (United States)

    Stihsen, Christoph; Pabinger, Christof; Radl, Roman; Rehak, Peter; Windhager, Reinhard

    2008-12-01

    The Duraloc cup is a frequently used metal-backed, porous-coated, hemispherical, press-fit acetabular component. Published data on loosening rates are contradictory. In this study we investigated migration patterns with computer-assisted Einzel-Bild-Roentgen-Analyse (EBRA) of 67 Duraloc 100 cups. Cup migration and clinical scores were analysed over a 5-year follow-up period. Median total migration of the Duraloc 100 cup was 1.21 mm at 5 years. Seventy-five percent of implants were radiologically stable at 2 years and 90% at 4 years. One cup loosened aseptically at 60 months, requiring revision. Cup diameters > or = 54 mm migrated significantly more than cups < 54 mm in diameter (p = 0.029 at 4 years). There was a significant correlation between high polyethylene wear and further migrating cups within the first post-operative year (p = 0.035 at 12 months). Our analysis revealed significantly higher wear in males (p = 0.029 at 4 years). Radiological loosening at two years could be calculated using receiver-operating characteristic curve analysis, and 1.2 mm as an adequate threshold value (sensitivity = 100%, specificity = 89%).

  15. [The productive structure and migration].

    Science.gov (United States)

    Fernandez, M

    1980-01-01

    The author discusses the possibility of determining the proper approach to the study of migration, with a focus on the importance of global, structural, and historical analysis of the phenomenon. A general theoretical outline is presented that tends to show migration as an integral part of the process of social change. The sociological focus on modernization as a theoretical guide influencing the study of migration in Latin America is evaluated. The concept of overpopulation is explained in relation to the migratory process, with reference to capitalist and non-capitalist forms of production.

  16. Migration of accreting giant planets

    Science.gov (United States)

    Robert, C.; Crida, A.; Lega, E.; Méheut, H.

    2017-09-01

    Giant planets forming in protoplanetary disks migrate relative to their host star. By repelling the gas in their vicinity, they form gaps in the disk's structure. If they are effectively locked in their gap, it follows that their migration rate is governed by the accretion of the disk itself onto the star, in a so-called type II fashion. Recent results showed however that a locking mechanism was still lacking, and was required to understand how giant planets may survive their disk. We propose that planetary accretion may play this part, and help reach this slow migration regime.

  17. Influence of basalt/groundwater interactions on radionuclide migration

    International Nuclear Information System (INIS)

    Vandegrift, G.F.

    1984-01-01

    The work presented here is a partial summary of the experimental results obtained in the Laboratory Analog Program. Two aspects of this effort are (1) the interaction between simulated basaltic groundwater and basalt fissures that were either freshly cleaved or laboratory altered by hydrothermal treatment with the simulated groundwater and (2) the effect of this interaction on radionuclide migration through these basalt fissures. The following conclusions of this study bear heavily on the predicted safety of a basalt repository: Sorption properties of freshly fissured basalt and naturally aged basalt are quite different for different chemical species. Analog experiments predict that aged basalt would be an effective retarder of cesium, but would be much less so for actinide elements. Distribution ratios measured from batch experiments with finely ground rock samples (presenting unaltered rock surfaces) are not a reliable means of predicting radionuclide migration in geological repositories. As the near-repository area is resaturated by groundwater, its ability to retard actinide migration will be degraded with time. Disturbing the natural flow of groundwater through the repository area by constructing and backfilling the repository will modify the composition of groundwater. This modified groundwater is likely to interact with and to modify naturally aged basalt surfaces downstream from the repository

  18. Foreign assistance

    International Nuclear Information System (INIS)

    1991-07-01

    This paper reports that providing energy assistance to developing countries remains a relatively low priority of the Agency for International Development. AID is helping some developing countries meet their energy needs, but this assistance varies substantially because of the agency's decentralized structure. Most AID energy funding has gone to a handful of countries-primarily Egypt and Pakistan. With limited funding in most other countries, AID concentrates on providing technical expertise and promoting energy policy reforms that will encourage both energy efficiency and leverage investment by the private sector and other donors. Although a 1989 congressional directive to pursue a global warming initiative has had a marginal impact on the agency's energy programming, many AID energy programs, including those directed at energy conservation, help address global warming concerns

  19. MRI of neuronal migration disorders

    International Nuclear Information System (INIS)

    Engelbrecht, V.

    1996-01-01

    Twenty-one MRI examinations of the brain were performed in 19 children with neuronal migration disorders. Multiplanar oriented spin-echo sequences were on a scanner with 1.5 T. In 8 children we performed an additional turbo-inversion recovery (TIR) sequence. Results of sonography or CT from five children were compared with MRI scans. Using the actual nomenclature, we found the following migration disorders: Lissencephaly (n=6), cobblestone lissencephaly with Walker-Warbung syndrome (WWS) (n=2), polymicrogyria and schizencephaly (n=2), focal heterotopia (n=5), diffuse heterotopie (n=2) and hemimegalencephaly (n=2). MRI was superior to CT and sonography in all children. Except for the two boys with WWS, the TIR sequence was the best to demonstrate the changes in migration disorder because of the high contrast between gray and white matter. We demonstrate the characteristic features of the different migration disorders and compare them with the existing literature. (orig.) [de

  20. The migration challenge for PAYG

    Czech Academy of Sciences Publication Activity Database

    Aslanyan, Gurgen

    2014-01-01

    Roč. 27, č. 4 (2014), s. 1023-1038 ISSN 0933-1433 Institutional support: RVO:67985998 Keywords : public pension s * PAYG * unskilled migration Subject RIV: AH - Economics Impact factor: 1.109, year: 2014

  1. The migration challenge for PAYG

    Czech Academy of Sciences Publication Activity Database

    Aslanyan, Gurgen

    2014-01-01

    Roč. 27, č. 4 (2014), s. 1023-1038 ISSN 0933-1433 Institutional support: PRVOUK-P23 Keywords : public pension s * PAYG * unskilled migration Subject RIV: AH - Economics Impact factor: 1.109, year: 2014

  2. Labour market frictions and migration

    NARCIS (Netherlands)

    Cremers, Jan

    2016-01-01

    The 4th contribution to the series INT-AR papers is dedicated to the methods of assessing labour market frictions. The paper provides a (brief) international comparison of the role of labour migration in solving these frictions.

  3. Fluid migration studies in salt

    International Nuclear Information System (INIS)

    Shefelbine, H.C.; Raines, G.E.

    1980-01-01

    This discussion will be limited to the migration of water trapped in the rock salt under the influence of the heat field produced by nuclear waste. This is of concern because hypotheticl scenarios have been advanced in which this fluid movement allows radionuclides to escape to the biosphere. While portions of these scenarios are supported by observation, none of the complete scenarios has been demonstrated. The objectives of the present fluid migration studies are two-fold: 1. determine the character of the trapped fluid in terms of quantity, habitat and chemical constituents; and 2. define the mechanisms that cause the fluid to migrate toward heat sources. Based on the observations to date, fluid migration will not have a major impact on repository integrity. However, the above objectives will be pursued until the impacts, if any, can be quantified

  4. Effort Estimation in BPMS Migration

    Directory of Open Access Journals (Sweden)

    Christopher Drews

    2018-04-01

    Full Text Available Usually Business Process Management Systems (BPMS are highly integrated in the IT of organizations and are at the core of their business. Thus, migrating from one BPMS solution to another is not a common task. However, there are forces that are pushing organizations to perform this step, e.g. maintenance costs of legacy BPMS or the need for additional functionality. Before the actual migration, the risk and the effort must be evaluated. This work provides a framework for effort estimation regarding the technical aspects of BPMS migration. The framework provides questions for BPMS comparison and an effort evaluation schema. The applicability of the framework is evaluated based on a simplified BPMS migration scenario.

  5. Return Migration and Working Choices

    OpenAIRE

    TANI, Massimiliano; MAHUTEAU, Stéphane

    2008-01-01

    Collective Action to Support the Reintegration of Return Migrants in their Country of Origin (MIREM) This paper uses the recent survey carried out in the framework of the MIREM project on returnees to Algeria, Morocco and Tunisia and studies the duration of emigration and the labour force status upon returning. The results suggest that age and the year of emigration play a central role in the migration decision, but they do not support the hypothesis that the duration of migration is deter...

  6. Roosts and migrations of swallows

    OpenAIRE

    Winkler, David W.

    2006-01-01

    Swallows of the north temperate zone display a wide variety of territorial behaviour during the breeding season, but as soon as breeding is over, they all appear to adopt a pattern of independent diurnal foraging interleaved with aggregation every night in dense roosts. Swallows generally migrate during the day, feeding on the wing. On many stretches of their annual journeys, their migrations can thus be seen as the simple spatial translation of nocturnal roost sites with foraging routes stra...

  7. International Student Migration to Germany

    OpenAIRE

    Donata Bessey

    2007-01-01

    This paper presents first empirical evidence on international student migration to Germany. I use a novel approach that analyzes student mobility using an augmented gravity equation and find evidence of strong network effects and of the importance of distance - results familiar from the empirical migration literature. However, the importance of disposable income in the home country does not seem to be too big for students, while the fact of being a politically unfree country decreases migrati...

  8. Effort Estimation in BPMS Migration

    OpenAIRE

    Drews, Christopher; Lantow, Birger

    2018-01-01

    Usually Business Process Management Systems (BPMS) are highly integrated in the IT of organizations and are at the core of their business. Thus, migrating from one BPMS solution to another is not a common task. However, there are forces that are pushing organizations to perform this step, e.g. maintenance costs of legacy BPMS or the need for additional functionality. Before the actual migration, the risk and the effort must be evaluated. This work provides a framework for effort estimation re...

  9. Grb7 SH2 domain structure and interactions with a cyclic peptide inhibitor of cancer cell migration and proliferation

    Directory of Open Access Journals (Sweden)

    Pero Stephanie C

    2007-09-01

    Full Text Available Abstract Background Human growth factor receptor bound protein 7 (Grb7 is an adapter protein that mediates the coupling of tyrosine kinases with their downstream signaling pathways. Grb7 is frequently overexpressed in invasive and metastatic human cancers and is implicated in cancer progression via its interaction with the ErbB2 receptor and focal adhesion kinase (FAK that play critical roles in cell proliferation and migration. It is thus a prime target for the development of novel anti-cancer therapies. Recently, an inhibitory peptide (G7-18NATE has been developed which binds specifically to the Grb7 SH2 domain and is able to attenuate cancer cell proliferation and migration in various cancer cell lines. Results As a first step towards understanding how Grb7 may be inhibited by G7-18NATE, we solved the crystal structure of the Grb7 SH2 domain to 2.1 Å resolution. We describe the details of the peptide binding site underlying target specificity, as well as the dimer interface of Grb 7 SH2. Dimer formation of Grb7 was determined to be in the μM range using analytical ultracentrifugation for both full-length Grb7 and the SH2 domain alone, suggesting the SH2 domain forms the basis of a physiological dimer. ITC measurements of the interaction of the G7-18NATE peptide with the Grb7 SH2 domain revealed that it binds with a binding affinity of Kd = ~35.7 μM and NMR spectroscopy titration experiments revealed that peptide binding causes perturbations to both the ligand binding surface of the Grb7 SH2 domain as well as to the dimer interface, suggesting that dimerisation of Grb7 is impacted on by peptide binding. Conclusion Together the data allow us to propose a model of the Grb7 SH2 domain/G7-18NATE interaction and to rationalize the basis for the observed binding specificity and affinity. We propose that the current study will assist with the development of second generation Grb7 SH2 domain inhibitors, potentially leading to novel inhibitors of

  10. Palaearctic-African Bird Migration

    DEFF Research Database (Denmark)

    Iwajomo, Soladoye Babatola

    Bird migration has attracted a lot of interests over past centuries and the methods used for studying this phenomenon has greatly improved in terms of availability, dimension, scale and precision. In spite of the advancements, relatively more is known about the spring migration of trans-Saharan m......Bird migration has attracted a lot of interests over past centuries and the methods used for studying this phenomenon has greatly improved in terms of availability, dimension, scale and precision. In spite of the advancements, relatively more is known about the spring migration of trans...... of birds from Europe to Africa and opens up the possibility of studying intra-African migration. I have used long-term, standardized autumn ringing data from southeast Sweden to investigate patterns in biometrics, phenology and population trends as inferred from annual trapping totals. In addition, I...... in the population of the species. The papers show that adult and juvenile birds can use different migration strategies depending on time of season and prevailing conditions. Also, the fuel loads of some individuals were theoretically sufficient for a direct flight to important goal area, but whether they do so...

  11. Investigation on nuclide migration behaviors

    International Nuclear Information System (INIS)

    Baik, Minhoon; Park, Chungkyun; Kim, Seungsoo

    2012-04-01

    In this study, we investigated the properties of geochemical reactions and sorption of high-level radionuclides and highly-mobile radionuclides in deep geological disposal environments. We also analyzed the dissolution properties of pyro wastes and constructed databases for the geochemical reactions and sorption for the safety assessment of HLW disposal. Technologies for measuring diffusion depths of radionuclides through fracture surfaces and rock matrix were developed in KURT conditions and their diffusion properties were analyzed and evaluated. The combined reactions of radionuclide/mineral/microbe in deep disposal environments were investigated and the effects of microbe on the radionuclide migration and disposal system behaviors were evaluated. In-situ solute migration system and on-line monitoring system were installed in KURT and the migration and retardation behaviors of various solutes and their interaction with fracture-filling materials were investigated. Basic properties of KURT groundwater colloids were analyzed using various methods. In addition, in-situ colloid migration experiments through a rock fracture were carried out and the developed migration model was verified. We have participated in Colloid Formation and Migration (CFM) international joint project in GTS and obtained reliability for our research results by comparing research results each other

  12. International labor migration and external debt.

    Science.gov (United States)

    Bustamante, J A

    1987-01-01

    The prevailing Mexican and US definitions of undocumented migration are poles apart. The US views it as a criminal problem. Mexicans view the undocumented migrants as actors in an economic game in which the rules are extremely disadvantageous to these migrants. Migrants themselves and their communities view the undocumented as a positive element. It is necessary to move toward a bilateral focus and bilateral negotiation on the issue of migratory workers. This proposal derives from several assumptions: 1) the external debt is a bilateral or multilateral issue, 2) it is important to avoid forcing debtor countries to choose between stimulating economic growth or making payment on their foreign debt, 3) prevailing public opinion in the US favors halting undocumented migration, 4) the US views the migration of undocumented Mexicans as the result of forces endogenous to Mexico and exogenous to the US, 5) the US views both Mexico's ability to make payment on its external debt and to halt emigration as tied to the Mexican government's ability or inability to reconcile political stability with scarce monetary resources, and 6) political instability in Mexico could augment emigration to the US and undermine Mexico's ability to address its foreign debt. The following proposal suggests means to link negotiation on the external debt to that of undocumented migration: 1) The Mexican government could reach an accord with the US to channel a portion of the actual interest on the external debt as a fund to be invested in Mexico to construct a system of labor intensive agroindustrial productive units designed to attract former or potential migratory workers; 2) the total amount of these funds would be deducted from interest payments on the principal of the actual external debt and redefined as an ad hoc loan to Mexico to finance these production units; 3) part of the production from these units would be incorporated into ongoing US food relief and food assistance programs; 4) the

  13. Migrating Pools in Yangtze River

    NARCIS (Netherlands)

    Li, Y.

    2002-01-01

    The severity and location of bank erosion and bed scour changes with the variation of water level. At low flows, the main flow thread tends to follow the concave bank. As the discharge increases, the flow tends to cut across the convex bar, to concentrate against concave bank only downstream the

  14. Downstream Antisense Transcription Predicts Genomic Features That Define the Specific Chromatin Environment at Mammalian Promoters.

    Directory of Open Access Journals (Sweden)

    Christopher A Lavender

    2016-08-01

    Full Text Available Antisense transcription is a prevalent feature at mammalian promoters. Previous studies have primarily focused on antisense transcription initiating upstream of genes. Here, we characterize promoter-proximal antisense transcription downstream of gene transcription starts sites in human breast cancer cells, investigating the genomic context of downstream antisense transcription. We find extensive correlations between antisense transcription and features associated with the chromatin environment at gene promoters. Antisense transcription downstream of promoters is widespread, with antisense transcription initiation observed within 2 kb of 28% of gene transcription start sites. Antisense transcription initiates between nucleosomes regularly positioned downstream of these promoters. The nucleosomes between gene and downstream antisense transcription start sites carry histone modifications associated with active promoters, such as H3K4me3 and H3K27ac. This region is bound by chromatin remodeling and histone modifying complexes including SWI/SNF subunits and HDACs, suggesting that antisense transcription or resulting RNA transcripts contribute to the creation and maintenance of a promoter-associated chromatin environment. Downstream antisense transcription overlays additional regulatory features, such as transcription factor binding, DNA accessibility, and the downstream edge of promoter-associated CpG islands. These features suggest an important role for antisense transcription in the regulation of gene expression and the maintenance of a promoter-associated chromatin environment.

  15. XCR1 promotes cell growth and migration and is correlated with bone metastasis in non-small cell lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ting; Han, Shuai; Wu, Zhipeng; Han, Zhitao; Yan, Wangjun; Liu, Tielong; Wei, Haifeng; Song, Dianwen; Zhou, Wang, E-mail: brilliant212@163.com; Yang, Xinghai, E-mail: cnspineyang@163.com; Xiao, Jianru, E-mail: jianruxiao83@163.com

    2015-08-21

    Bone metastasis occurs in approximately 30–40% patients with advanced non-small cell lung cancer (NSCLC), but the mechanism underlying this bone metastasis remains poorly understood. The chemokine super family is believed to play an important role in tumor metastasis in lung cancer. The chemokine receptor XCR1 has been identified to promote cell proliferation and migration in oral cancer and ovarian carcinoma, but the role of XCR1 in lung cancer has not been reported. In this study, we demonstrated for the first time that XCR1 was overexpressed in lung cancer bone metastasis as compared with that in patients with primary lung cancer. In addition, the XCR1 ligand XCL1 promoted the proliferation and migration of lung cancer cells markedly, and knockdown of XCR1 by siRNA abolished the effect of XCL1 in cell proliferation and migration. Furthermore, we identified JAK2/STAT3 as a novel downstream pathway of XCR1, while XCL1/XCR1 increased the mRNA level of the downstream of JAK2/STAT3 including PIM1, JunB, TTP, MMP2 and MMP9. These results indicate that XCR1 is a new potential therapeutic target for the treatment of lung cancer bone metastasis. - Highlights: • XCR1 is overexpressed in bone metastasis compared with primary NSCLC. • XCR1 activation by XCL1 promotes lung cancer cell proliferation and migration. • JAK2/STAT3 is a novel potential downstream pathway of XCR1.

  16. Agmatine promotes the migration of murine brain endothelial cells via multiple signaling pathways.

    Science.gov (United States)

    Jung, Hyun-Joo; Jeon, Yong-Heui; Bokara, Kiran Kumar; Koo, Bon-Nyeo; Lee, Won Taek; Park, Kyung Ah; Lee, Jong-Eun

    2013-01-17

    The combination of adhesion and migration of endothelial cells (ECs) is an integral process for evolution, organization, repair and vessel formation in living organisms. Agmatine, a polycationic amine existing in brain, has been investigated to exert neuroprotective effects. Up to date, there are no studies reporting that agmatine modulates murine brain endothelial (bEnd.3) cells migration. In the present study, we intend to investigate the role of agmatine in bEnd.3 cells migration and the molecular mechanism mediating this action. The effect of agmatine on the bEnd.3 cells migration was examined by migration assay, and the mechanism involved for this effect was investigated by western blot analysis and NO contents measurements. Agmatine treatment (50, 100 and 200 μM) significantly accelerated bEnd.3 cells migration in a concentration-dependent manner. Western blotting revealed that agmatine treatment significantly induced vascular endothelial growth factor (VEGF), VEGF receptor 2 (Flk-1/KDR or VEGFR2), phosphatidylinositol 3-kinase (PI3K), Akt/protein kinase B (also known as PKB, PI3K downstream effector protein), endothelial nitric oxide synthase (eNOS) nitric oxide (NO; product by eNOS) and intercellular adhesion molecule 1 (ICAM-1) expressions during bEnd.3 cells migration. The expression of ICAM-1 and migration of bEnd.3 cells, induced by agmatine, were significantly attenuated by treatment of wortmannin, a specific PI3K inhibitor. Taken together, we provide the first evidence that activation of VEGF/VEGFR2 and the consequential PI3K/Akt/eNOS/NO/ICAM-1 signaling pathways are serial events, through which the treatment of agmatine could lead to bEnd.3 cells migration. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. Physiological mechanisms of imprinting and homing migration in Pacific salmon Oncorhynchus spp.

    Science.gov (United States)

    Ueda, H

    2012-07-01

    After several years of feeding at sea, salmonids have an amazing ability to migrate long distances from the open ocean to their natal stream to spawn. Three different research approaches from behavioural to molecular biological studies have been used to elucidate the physiological mechanisms underpinning salmonid imprinting and homing migration. The study was based on four anadromous Pacific salmon Oncorhynchus spp., pink salmon Oncorhynchus gorbuscha, chum salmon Oncorhynchus keta, sockeye salmon Oncorhynchus nerka and masu salmon Oncorhynchus masou, migrating from the North Pacific Ocean to the coast of Hokkaido, Japan, as well as lacustrine O. nerka and O. masou in Lake Toya, Hokkaido, where the lake serves as the model oceanic system. Behavioural studies using biotelemetry techniques showed swimming profiles from the Bering Sea to the coast of Hokkaido in O. keta as well as homing behaviours of lacustrine O. nerka and O. masou in Lake Toya. Endocrinological studies on hormone profiles in the brain-pituitary-gonad axis of O. keta, and lacustrine O. nerka identified the hormonal changes during homing migration. Neurophysiological studies revealed crucial roles of olfactory functions on imprinting and homing during downstream and upstream migration, respectively. These findings are discussed in relation to the physiological mechanisms of imprinting and homing migration in anadromous and lacustrine salmonids. © 2012 The Author. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

  18. PDGF controls contact inhibition of locomotion by regulating N-cadherin during neural crest migration.

    Science.gov (United States)

    Bahm, Isabel; Barriga, Elias H; Frolov, Antonina; Theveneau, Eric; Frankel, Paul; Mayor, Roberto

    2017-07-01

    A fundamental property of neural crest (NC) migration is contact inhibition of locomotion (CIL), a process by which cells change their direction of migration upon cell contact. CIL has been proven to be essential for NC migration in amphibians and zebrafish by controlling cell polarity in a cell contact-dependent manner. Cell contact during CIL requires the participation of the cell adhesion molecule N-cadherin, which starts to be expressed by NC cells as a consequence of the switch between E- and N-cadherins during epithelial-to-mesenchymal transition (EMT). However, the mechanism that controls the upregulation of N-cadherin remains unknown. Here, we show that platelet-derived growth factor receptor alpha (PDGFRα) and its ligand platelet-derived growth factor A (PDGF-A) are co-expressed in migrating cranial NC. Inhibition of PDGF-A/PDGFRα blocks NC migration by inhibiting N-cadherin and, consequently, impairing CIL. Moreover, we identify phosphatidylinositol-3-kinase (PI3K)/AKT as a downstream effector of the PDGFRα cellular response during CIL. Our results lead us to propose PDGF-A/PDGFRα signalling as a tissue-autonomous regulator of CIL by controlling N-cadherin upregulation during EMT. Finally, we show that once NC cells have undergone EMT, the same PDGF-A/PDGFRα works as an NC chemoattractant, guiding their directional migration. © 2017. Published by The Company of Biologists Ltd.

  19. Measurement of velocity deficit at the downstream of a 1:10 axial hydrokinetic turbine model

    Energy Technology Data Exchange (ETDEWEB)

    Gunawan, Budi [ORNL; Neary, Vincent S [ORNL; Hill, Craig [St. Anthony Falls Laboratory, 2 Third Avenue SE, Minneapolis, MN 55414; Chamorro, Leonardo [St. Anthony Falls Laboratory, 2 Third Avenue SE, Minneapolis, MN 55414

    2012-01-01

    Wake recovery constrains the downstream spacing and density of turbines that can be deployed in turbine farms and limits the amount of energy that can be produced at a hydrokinetic energy site. This study investigates the wake recovery at the downstream of a 1:10 axial flow turbine model using a pulse-to-pulse coherent Acoustic Doppler Profiler (ADP). In addition, turbine inflow and outflow velocities were measured for calculating the thrust on the turbine. The result shows that the depth-averaged longitudinal velocity recovers to 97% of the inflow velocity at 35 turbine diameter (D) downstream of the turbine.

  20. Erk5 inhibits endothelial migration via KLF2-dependent down-regulation of PAK1.

    Science.gov (United States)

    Komaravolu, Ravi K; Adam, Christian; Moonen, Jan-Renier A J; Harmsen, Martin C; Goebeler, Matthias; Schmidt, Marc

    2015-01-01

    The MEK5/Erk5 pathway mediates beneficial effects of laminar flow, a major physiological factor preventing vascular dysfunction. Forced Erk5 activation induces a protective phenotype in endothelial cell (EC) that is associated with a dramatically decreased migration capacity of those cells. Transcriptional profiling identified the Krüppel-like transcription factors KLF2 and KLF4 as central mediators of Erk5-dependent gene expression. However, their downstream role regarding migration is unclear and relevant secondary effectors remain elusive. Here, we further investigated the mechanism underlying Erk5-dependent migration arrest in ECs. Our experiments reveal KLF2-dependent loss of the pro-migratory Rac/Cdc42 mediator, p21-activated kinase 1 (PAK1), as an important mechanism of Erk5-induced migration inhibition. We show that endothelial Erk5 activation by expression of a constitutively active MEK5 mutant, by statin treatment, or by application of laminar shear stress strongly decreased PAK1 mRNA and protein expression. Knockdown of KLF2 but not of KLF4 prevented Erk5-mediated PAK1 mRNA inhibition, revealing KLF2 as a novel PAK1 repressor in ECs. Importantly, both PAK1 re-expression and KLF2 knockdown restored the migration capacity of Erk5-activated ECs underscoring their functional relevance downstream of Erk5. Our data provide first evidence for existence of a previously unknown Erk5/KLF2/PAK1 axis, which may limit undesired cell migration in unperturbed endothelium and lower its sensitivity for migratory cues that promote vascular diseases including atherosclerosis. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

  1. MicroRNA-218 inhibits cell invasion and migration of pancreatic cancer via regulating ROBO1.

    Science.gov (United States)

    He, Hang; Hao, Si-Jie; Yao, Lie; Yang, Feng; Di, Yang; Li, Ji; Jiang, Yong-Jian; Jin, Chen; Fu, De-Liang

    2014-10-01

    miRNA-218 is a highlighted tumor suppressor and its underlying role in tumor progression is still unknown. Here, we restored the expression of miRNA-218 in pancreatic cancer to clarify the function and potent downstream pathway of miRNA-218. The expressions of both miRNA-218 and its potent target gene ROBO1 were revealed by RT-PCR and western blotting analysis. Transfection of miRNA-218 precursor mimics and luciferase assay were performed to elucidate the regulation mechanism between miRNA-218 and ROBO1. Cells, stably expressing miRNA-218 followed by forced expression of mutant ROBO1, were established through co-transfections of both lentivirus vector and plasmid vector. The cell migration and invasion abilities were evaluated by migration assay and invasion assay respectively. An increased expression of ROBO1 was revealed in cell BxPC-3-LN compared with cell BxPC-3. Elevated expression of miRNA-218 would suppress the expression of ROBO1 via complementary binding to a specific region within 3'UTR of ROBO1 mRNA (sites 971-978) in pancreatic cancer cells. Stably restoring the expression of miRNA-218 in pancreatic cancer significantly downregulated the expression of ROBO1 and effectively inhibited cell migration and invasion. Forced expression of mutant ROBO1 could reverse the repression effects of miRNA-218 on cell migration and invasion. Consequently, miRNA-218 acted as a tumor suppressor in pancreatic cancer by inhibiting cell invasion and migration. ROBO1 was a functional target of miRNA-218's downstream pathway involving in cell invasion and migration of pancreatic cancer.

  2. Periodic sediment shift in migrating ripples influences benthic microbial activity

    Science.gov (United States)

    Zlatanović, Sanja; Fabian, Jenny; Mendoza-Lera, Clara; Woodward, K. Benjamin; Premke, Katrin; Mutz, Michael

    2017-06-01

    Migrating bedforms have high levels of particulate organic matter and high rates of pore water exchange, causing them to be proposed as hot spots of carbon turnover in rivers. Yet, the shifting of sediments and associated mechanical disturbance within migrating bedforms, such as ripples, may stress and abrade microbial communities, reducing their activity. In a microcosm experiment, we replicated the mechanical disturbances caused by the periodic sediment shift within ripples under oligotrophic conditions. We assessed the effects on fungal and bacterial biomass ratio (F:B), microbial community respiration (CR), and bacterial production (BCP) and compared with stable undisturbed sediments. Interactions between periodic mechanical disturbance and sediment-associated particulate organic matter (POM) were tested by enriching sediments collected from migrating ripples with different qualities of POM (fish feces, leaf litter fragments and no addition treatments). F:B and BCP were affected by an interaction between mechanical disturbance and POM quality. Fish feces enriched sediments showed increased F:B and BCP compared to sediments with lower POM quality and responded with a decrease of F:B and BCP to sediment disturbance. In the other POM treatments F:B and BCP were not affected by disturbance. Microbial respiration was however reduced by mechanical disturbance to similar low activity levels regardless of POM qualities added, whereas fish feces enriched sediment showed short temporary boost of CR. With the worldwide proliferation of migrating sand ripples due to massive catchment erosion, suppressed mineralization of POM will increasingly affect stream metabolism, downstream transport of POM and carbon cycling from reach to catchment scale.

  3. International migration: a global challenge.

    Science.gov (United States)

    Martin, P; Widgren, J

    1996-04-01

    Trends in international migration are presented in this multiregional analysis. Seven of the world's wealthiest countries have about 33% of the world's migrant population, but under 16% of the total world population. Population growth in these countries is substantially affected by the migrant population. The migration challenge is external and internal. The external challenge is to balance the need for foreign labor and the commitment to human rights for those migrants seeking economic opportunity and political freedom. The internal challenge is to assure the social adjustment of immigrants and their children and to integrate them into society as citizens and future leaders. Why people cross national borders and how migration flows are likely to evolve over the next decades are explained. This report also presents some ways that countries can manage migration or reduce the pressures which force people to migrate. It is recommended that receiving nations control immigration by accelerating global economic growth and reducing wars and human rights violations. This report examines the impact of immigration on international trade, aid, and direct intervention policies. Although migration is one of the most important international economic issues, it is not coordinated by an international group. The European experience indicates that it is not easy to secure international cooperation on issues that affect national sovereignty. It is suggested that countries desiring control of their borders should remember that most people never cross national borders to live or work in another country, that 50% of the world's migrants move among developing countries, and that countries can shift from being emigration to immigration countries. The author suggests that sustained reductions in migration pressure are a better alternative than the "quick fixes" that may invite the very much feared mass and unpredictable movements.

  4. Bacurd2 is a novel interacting partner to Rnd2 which controls radial migration within the developing mammalian cerebral cortex.

    Science.gov (United States)

    Gladwyn-Ng, Ivan Enghian; Li, Shan Shan; Qu, Zhengdong; Davis, John Michael; Ngo, Linh; Haas, Matilda; Singer, Jeffrey; Heng, Julian Ik-Tsen

    2015-03-31

    During fetal brain development in mammals, newborn neurons undergo cell migration to reach their appropriate positions and form functional circuits. We previously reported that the atypical RhoA GTPase Rnd2 promotes the radial migration of mouse cerebral cortical neurons (Nature 455(7209):114-8, 2008; Neuron 69(6):1069-84, 2011), but its downstream signalling pathway is not well understood. We have identified BTB-domain containing adaptor for Cul3-mediated RhoA degradation 2 (Bacurd2) as a novel interacting partner to Rnd2, which promotes radial migration within the developing cerebral cortex. We find that Bacurd2 binds Rnd2 at its C-terminus, and this interaction is critical to its cell migration function. We show that forced expression or knockdown of Bacurd2 impairs neuronal migration within the embryonic cortex and alters the morphology of immature neurons. Our in vivo cellular analysis reveals that Bacurd2 influences the multipolar-to-bipolar transition of radially migrating neurons in a cell autonomous fashion. When we addressed the potential signalling relationship between Bacurd2 and Rnd2 using a Bacurd2-Rnd2 chimeric construct, our results suggest that Bacurd2 and Rnd2 could interact to promote radial migration within the embryonic cortex. Our studies demonstrate that Bacurd2 is a novel player in neuronal development and influences radial migration within the embryonic cerebral cortex.

  5. The Hem protein mediates neuronal migration by inhibiting WAVE degradation and functions opposite of Abelson tyrosine kinase

    Science.gov (United States)

    Zhu, Zengrong; Bhat, Krishna Moorthi

    2011-01-01

    In the nervous system, neurons form in different regions, then they migrate and occupy specific positions. We have previously shown that RP2/sib, a well-studied neuronal pair in the Drosophila ventral nerve cord (VNC), has a complex migration route. Here, we show that the Hem protein, via the WAVE complex, regulates migration of GMC-1 and its progeny RP2 neuron. In Hem or WAVE mutants, RP2 neuron either abnormally migrates, crossing the midline from one hemisegment to the contralateral hemisegment, or does not migrate at al and fail to send out its axon projection. We report that Hem regulates neuronal migration through stabilizing WAVE. Since Hem and WAVE normally form a complex, our data argues that in the absence of Hem, WAVE, which is presumably no longer in a complex, becomes susceptible to degradation. We also find that Abelson Tyrosine kinase affects RP2 migration in a similar manner as Hem and WAVE, and appears to operate via WAVE. However, while Abl negatively regulates the levels of WAVE, it regulates migration via regulating the activity of WAVE. Our results also show that during the degradation of WAVE, Hem function is opposite to that of and downstream of Abl. PMID:21726548

  6. Evidence for density-dependent changes in growth, downstream movement, and size of Chinook salmon subyearlings in a large-river landscape

    Science.gov (United States)

    Connor, William P.; Tiffan, Kenneth F.; Plumb, John M.; Moffit, Christine M.

    2013-01-01

    We studied the growth rate, downstream movement, and size of naturally produced fall Chinook Salmon Oncorhynchus tshawytscha subyearlings (age 0) for 20 years in an 8th-order river landscape with regulated riverine upstream rearing areas and an impounded downstream migration corridor. The population transitioned from low to high abundance in association with U.S. Endangered Species Act and other federally mandated recovery efforts. The mean growth rate of parr in the river did not decline with increasing abundance, but during the period of higher abundance the timing of dispersal from riverine habitat into the reservoir averaged 17 d earlier and the average size at the time of downstream dispersal was smaller by 10 mm and 1.8 g. Changes in apparent abundance, measured by catch per unit effort, largely explained the time of dispersal, measured by median day of capture, in riverine habitat. The growth rate of smolts in the reservoir declined from an average of 0.6 to 0.2 g/d between the abundance periods because the reduction in size at reservoir entry was accompanied by a tendency to migrate rather than linger and by increasing concentrations of smolts in the reservoir. The median date of passage through the reservoir was 14 d earlier on average, and average smolt size was smaller by 38 mm and 22.0 g, in accordance with density-dependent behavioral changes reflected by decreased smolt growth. Unexpectedly, smolts during the high-abundance period had begun to reexpress the migration timing and size phenotypes observed before the river was impounded, when abundance was relatively high. Our findings provide evidence for density-dependent phenotypic change in a large river that was influenced by the expansion of a recovery program. Thus, this study shows that efforts to recover native fishes can have detectable effects in large-river landscapes. The outcome of such phenotypic change, which will be an important area of future research, can only be fully judged by

  7. Physical and Chemical Connectivity of Streams and Riparian Wetlands to Downstream Waters: A Synthesis

    Science.gov (United States)

    Streams, riparian areas, floodplains, alluvial aquifers, and downstream waters (e.g., large rivers, lakes, and oceans) are interconnected by longitudinal, lateral, and vertical fluxes of water, other materials, and energy. Collectively, these interconnected waters are called fluv...

  8. The dynamics of entrepreneurship in ICT: case of mobile phones downstream services in Kenya

    NARCIS (Netherlands)

    R.N. Kanothi (Raphael)

    2009-01-01

    textabstractThe research paper explores the extent to which mobile phones downstream services, defined here as those provided using the existing connectivity, are generating opportunities for entrepreneurship development in Kenya. After identifying the services of mobile payphones, money transfer

  9. Evaluation of a Solid Phase DNA Binding Matrix for Downstream PCR Analysis

    National Research Council Canada - National Science Library

    Bader, Douglas E; Fisher, Glen R; Stratilo, Chad W

    2005-01-01

    A commercially available solid-phase DNA binding matrix (FTA cards) was evaluated for its ability to capture and release DNA for downstream gene amplification and detection assays using polymerase chain reaction (PCR...

  10. Long-Term Live Cell Imaging of Cell Migration: Effects of Pathogenic Fungi on Human Epithelial Cell Migration.

    Science.gov (United States)

    Wöllert, Torsten; Langford, George M

    2016-01-01

    Long-term live cell imaging was used in this study to determine the responses of human epithelial cells to pathogenic biofilms formed by Candida albicans. Epithelial cells of the skin represent the front line of defense against invasive pathogens such as C. albicans but under certain circumstances, especially when the host's immune system is compromised, the skin barrier is breached. The mechanisms by which the fungal pathogen penetrates the skin and invade the deeper layers are not fully understood. In this study we used keratinocytes grown in culture as an in vitro model system to determine changes in host cell migration and the actin cytoskeleton in response to virulence factors produced by biofilms of pathogenic C. albicans. It is clear that changes in epithelial cell migration are part of the response to virulence factors secreted by biofilms of C. albicans and the actin cytoskeleton is the downstream effector that mediates cell migration. Our goal is to understand the mechanism by which virulence factors hijack the signaling pathways of the actin cytoskeleton to alter cell migration and thereby invade host tissues. To understand the dynamic changes of the actin cytoskeleton during infection, we used long-term live cell imaging to obtain spatial and temporal information of actin filament dynamics and to identify signal transduction pathways that regulate the actin cytoskeleton and its associated proteins. Long-term live cell imaging was achieved using a high resolution, multi-mode epifluorescence microscope equipped with specialized light sources, high-speed cameras with high sensitivity detectors, and specific biocompatible fluorescent markers. In addition to the multi-mode epifluorescence microscope, a spinning disk confocal long-term live cell imaging system (Olympus CV1000) equipped with a stage incubator to create a stable in vitro environment for long-term real-time and time-lapse microscopy was used. Detailed descriptions of these two long-term live

  11. International nurse migrations: Global trends

    Directory of Open Access Journals (Sweden)

    Ivković Marija

    2011-01-01

    Full Text Available This paper presents global trends of migration of nurses, as specific qualified personnel in high demand. In the last couple of decades, and especially in the last couple of years, many countries have faced the problem of insufficient healthcare workers, particularly nurses. Reasons for this occurrence might be found in the deficiencies of their education systems, as well as the population aging of northern and western countries. As a response to this deficiency, those countries have begun intensive recruitment of foreign qualified female healthcare workers, which has led to the point that nurse migration today presents a very intense, and by many accounts specific migration flow. Female migrating work force is often in pursuit of low-wage and lowqualified work. Nurse migration is actually an example of motion of qualified female migrants in pursuit for better employment opportunities. While such a way of filling up the vacant positions works for the “importing” countries as a temporary solution, departure of trained female personnel presents a significant loss for the originating countries. In this paper we pay special attention to the countries who are the main “importers”, but also to those who are “exporters” of nursing personnel, and to specific national strategies these countries have applied.

  12. Downstream wind flow path diversion and its effects on the performance of vertical axis wind turbine

    International Nuclear Information System (INIS)

    Maganhar, A.L.

    2015-01-01

    In the present experimental study efforts have been made to analysis path diversion effect of downstream wind flow on performance of vertical axis wind turbine (VAWT). For the blockage of downstream wind flow path at various linear displaced positions, a normal erected flat wall, semi-circular and cylindrical shapes were tested for path diverting geometries. Performance of VAWT in terms of improved rotor speed up to 45% was achieved. (author)

  13. Bioactive Carbohydrates and Peptides in Foods: An Overview of Sources, Downstream Processing Steps and Associated Bioactivities.

    Science.gov (United States)

    Hayes, Maria; Tiwari, Brijesh K

    2015-09-17

    Bioactive peptides and carbohydrates are sourced from a myriad of plant, animal and insects and have huge potential for use as food ingredients and pharmaceuticals. However, downstream processing bottlenecks hinder the potential use of these natural bioactive compounds and add cost to production processes. This review discusses the health benefits and bioactivities associated with peptides and carbohydrates of natural origin and downstream processing methodologies and novel processes which may be used to overcome these.

  14. Influence of Upstream and Downstream Compressor Stators on Rotor Exit Flow Field

    Directory of Open Access Journals (Sweden)

    Nicole L. Key

    2014-01-01

    Full Text Available Measurements acquired at the rotor exit plane illuminate the interaction of the rotor with the upstream vane row and the downstream vane row. The relative phase of the upstream and downstream vane rows is adjusted using vane clocking so that the effect of the upstream propagating potential field from the downstream stator can be distinguished from the effects associated with the wakes shed from the upstream stator. Unsteady absolute flow angle information shows that the downstream potential field causes the absolute flow angle to increase in the vicinity of the downstream stator leading edge. The presence of Stator 1 wake is also detected at this measurement plane using unsteady total pressure data. The rotor wakes are measured at different circumferential locations across the vane passage, and the influence of Stator 1 wake on the suction side of the rotor wake is evident. Also, the influence of the downstream stator is detected on the pressure side of the rotor wake for a particular clocking configuration. Understanding the role of the surrounding vane rows on rotor wake development will lead to improved comparison between experimental data and results from computational models.

  15. 22 CFR Appendix A to Part 218 - List of Federal Financial Assistance

    Science.gov (United States)

    2010-04-01

    ... Department of State Subject to Age Discrimination Regulations Resettlement of Refugees in the United States Under the Migration and Refugee Assistant Act of 1962, as amended (22 U.S.C. 2601 et seq.). Diplomat in...

  16. 22 CFR Appendix A to Part 143 - List of Affected Federal Financial Assistance

    Science.gov (United States)

    2010-04-01

    ... Administered by the Department of State Subject to Age Discrimination Regulations Resettlement of Refugees in the United States Under the Migration and Refugee Assistant Act of 1962, as amended (22 U.S.C. 2601 et...

  17. Rural migration and health care

    DEFF Research Database (Denmark)

    Svendsen, Gunnar Lind Haase; Jensen, Marit Vatn

    This literature study focuses on possible links between access to health services and migration in rural areas. Why do people move to or from rural areas or why do they stay? What determines where people settle? And, in this context, do local health care services play an important or minor role......, or no role at all? First, the paper reports on key findings from rural migration studies, in order to shed light on two migration trends: urbanization and counter-urbanization. Then we take a closer look on settlement preferences in rural areas, including the impact of health care facilities. Finally, we end...... up with a more deepgoing review of the relatively small number of studies, which explicitly deal with settlement preferences related to access to health care....

  18. Migration and the Wage Curve:

    DEFF Research Database (Denmark)

    Brücker, Herbert; Jahn, Elke J.

    in a general equilibrium framework. For the empirical analysis we employ the IABS, a two percent sample of the German labor force. We find that the elasticity of the wage curve is particularly high for young workers and workers with a university degree, while it is low for older workers and workers......  Based on a wage curve approach we examine the labor market effects of migration in Germany. The wage curve relies on the assumption that wages respond to a change in the unemployment rate, albeit imperfectly. This allows one to derive the wage and employment effects of migration simultaneously...... with a vocational degree. The wage and employment effects of migration are moderate: a 1 percent increase in the German labor force through immigration increases the aggregate unemployment rate by less than 0.1 percentage points and reduces average wages by less 0.1 percent. While native workers benefit from...

  19. Focus: Asian migration to Canada.

    Science.gov (United States)

    Kobayashi, A

    1988-01-01

    This collection of 5 short essays on Asian migration to Canada focuses on the relationships between individual migrants and their social contexts, both Asian and Canadian. Papers by Anderson and Kobayashi adopt research perspectives of outsider and insider, respectively. Vibert provides a historical overview against which the substantive issues introduced in the other 3 papers can be understood, and he illustrates the links between circumstances of migration and the larger issues by which the course of Canadian social progress has been steered. Mercer provides an introduction to issues that dominate the agenda of contemporary research, to show that Canadian communities of Asian heritage continue to grow in size, diversity, and complexity, as they become more established on the Canadian landscape. This collection is as much about the geography of racism as it is about migration.

  20. Families, children, migration and AIDS.

    Science.gov (United States)

    Haour-Knipe, Mary

    2009-01-01

    Migration is very often a family affair, and often involves children, directly or indirectly. It may give rise to better quality of life for an entire family, or to bitter disappointment, and may also increase vulnerability to HIV and AIDS. This review, carried out for the Joint Learning Initiative on Children and AIDS, links the literature on "migration", on "HIV and AIDS" and on "families". Three themes are sketched: (1) As both HIV prevalence and circular migration increase, former migrant workers affected by AIDS may return to their families for care and support, especially at the end of life, often under crisis conditions. Families thus lose promising members, as well as sources of support. However, very little is known about the children of such migrants. (2) Following patterns of migration established for far different reasons, children may have to relocate to different places, sometimes over long distances, if their AIDS-affected parents can no longer care for them. They face the same adaptation challenges as other children who move, but complicated by loss of parent(s), AIDS stigma, and often poverty. (3) The issue of migrant families living with HIV has been studied to some extent, but mainly in developed countries with a long history of migration, and with little attention paid to the children in such families. Difficulties include involuntary separation from family members, isolation and lack of support, disclosure and planning for children's care should the parent(s) die and differences in treatment access within the same family. Numerous research and policy gaps are defined regarding the three themes, and a call is made for thinking about migration, families and AIDS to go beyond description to include resilience theory, and to go beyond prevention to include care.

  1. Migration and Deforestation in Indonesia

    OpenAIRE

    Rivayani Darmawan; Stephan Klasen; Nunung Nuryartono

    2015-01-01

    Indonesia now has the highest deforestation rate in the world, with an average increase of about 47,600 ha per year. As a result, the nation is one of the largest emitters of greenhouse gases in the world and is putting its rich biodiversity at risk. Although the literature discussing the political economy of Indonesia commercial's logging is growing, only a small amount focuses on the relation-ship between migration and deforestation. Migration may contribute to the forest cover change, as m...

  2. Voluntary income redistribution with migration.

    Science.gov (United States)

    Crane, R

    1992-01-01

    This study is concerned with the welfare magnet problem, in which disparities in transfer policies across states are believed to encourage recipient and possibly resource migration. "This study clarifies the terms of the debate by showing how the value of redistributing local resources depends not only on the value of income to each group, but also on the cost of the transfer in erosion of the resource base through migration and through the general equilibrium effects of such activity on local prices." The geographical focus is on the United States. excerpt

  3. Women’s football migration

    DEFF Research Database (Denmark)

    Agergaard, Sine

    What is intriguing about women’s football as a cultural phenomenon is that unlike men’s football the finances and media interest for the game are sparse. Nevertheless we have found that migration of female football players is growing steadily and women’s football is becoming global in nature....... The question is then what drives this globalization process? According to our study of women’s football migration into Scandinavia, one of the centers of women’s football, transnational networks play a crucial role in mobilizing global migratory moves. Using the concept of friends-of-friends networks from Bale...

  4. Business cycles, migration and health.

    Science.gov (United States)

    Halliday, Timothy J

    2007-04-01

    We investigate the proposition that illness poses as an obstacle to one's ability to use migration to hedge the business cycle. We employ data on migration, regional unemployment rates and health status from 10 years (1984-1993) of the US Panel Study of Income Dynamics. Our results provide considerable for support this proposition. The evidence is the strongest for men, but we also find weaker evidence for married women. These results suggest that--ceterus paribus--aggregate health outcomes in an area should improve when the regional economy expands.

  5. Rural migration in southern Nevada

    International Nuclear Information System (INIS)

    Mosser, D.; Soden, D.L.

    1993-01-01

    This study reviews the history of migration in two rural counties in Southern Nevada. It is part of a larger study about the impact of a proposed high-level nuclear waste repository on, in and out-migration patterns in the state. The historical record suggests a boom and bust economic cycle has predominated in the region for the past century creating conditions that should be taken into account, by decision makers, when ascertaining the long-term impacts of the proposed repository

  6. Retirement migration and military retirement

    International Nuclear Information System (INIS)

    1988-06-01

    This report addresses questions relevant to a socioeconomic assessment system for southern Nevada. They point to an understanding of the magnitude of impacts which may occur if the Yucca Mountain Project were to affect the decision-making process which leads these groups to migrate to southern Nevada. This is an important but somewhat elusive topic lacking in standard data sources. However, the topic may be addressed and analyzed systematically. This report presents the results of efforts to develop a data base and begin development of a model to address the migration, income and expenditure dimensions of these groups. 1 fig., 62 tabs

  7. Automation of Flexible Migration Workflows

    Directory of Open Access Journals (Sweden)

    Dirk von Suchodoletz

    2011-03-01

    Full Text Available Many digital preservation scenarios are based on the migration strategy, which itself is heavily tool-dependent. For popular, well-defined and often open file formats – e.g., digital images, such as PNG, GIF, JPEG – a wide range of tools exist. Migration workflows become more difficult with proprietary formats, as used by the several text processing applications becoming available in the last two decades. If a certain file format can not be rendered with actual software, emulation of the original environment remains a valid option. For instance, with the original Lotus AmiPro or Word Perfect, it is not a problem to save an object of this type in ASCII text or Rich Text Format. In specific environments, it is even possible to send the file to a virtual printer, thereby producing a PDF as a migration output. Such manual migration tasks typically involve human interaction, which may be feasible for a small number of objects, but not for larger batches of files.We propose a novel approach using a software-operated VNC abstraction layer in order to replace humans with machine interaction. Emulators or virtualization tools equipped with a VNC interface are very well suited for this approach. But screen, keyboard and mouse interaction is just part of the setup. Furthermore, digital objects need to be transferred into the original environment in order to be extracted after processing. Nevertheless, the complexity of the new generation of migration services is quickly rising; a preservation workflow is now comprised not only of the migration tool itself, but of a complete software and virtual hardware stack with recorded workflows linked to every supported migration scenario. Thus the requirements of OAIS management must include proper software archiving, emulator selection, system image and recording handling. The concept of view-paths could help either to automatically determine the proper pre-configured virtual environment or to set up system

  8. Cladding Heatup Prediction between Spacer Grids for the Downstream Effect Evaluation

    International Nuclear Information System (INIS)

    Park, J. Y.; Kim, M. W.

    2009-01-01

    Since a recirculation sump clogging issue by debris generated from high energy pipe line break had been invoked as GSI-191 in the US, many researches on this issue have been undertaken. Previous researches on this topic are well summarized in Bang et al. Due to comprehensive nature of the issue, it includes many area of research and one of them is the area of downstream effect evaluation. The downstream effect is involved with adverse effects of debris passing the sump screen on the downstream systems, components and piping including core and it can be further divided into an ex-vessel downstream effect and an in-vessel downstream effect. In the ex-vessel downstream effect, focus is laid on plugging of spray nozzle, wearing and abrasion of moving parts of pump and valve and etc. Otherwise, a debris effect on reactor core is focused in the in-vessel downstream effect. Since debris can be ingested in the core or the systems of downstream of sump screen during recirculation, basically the downstream effect influences long-term core cooling phase. With respect to the in-vessel downstream effect, an up-to-date evaluation methodology is well summarized in a topical report submitted to the US nuclear regulatory commission by the pressurized water reactor owners group (PWROG). The report evaluates various aspects of debris ingestion in the core such as blockage at the core inlet, collection of debris on fuel grids, plating-out of fuel, chemical precipitants, protective coatings effect and etc. Most of them are evaluated qualitative manner based on previous research results and geometrical consideration on fuel rod bundles but some of them are also backed up by quantitative calculations to corroborate the qualitative decisions. One of them is a cladding heatup calculation between spacer grids. This is done to demonstrate that the cladding temperature of a fuel rod between grids with debris deposited on the clad surface in a post- LOCA recirculation environment is below

  9. Interactions between Channel Morphology and the Propagation of Coarse Sediment Augmentations Downstream from Dams

    Science.gov (United States)

    Gaeuman, D. A.; Dickenson, S.; Pyles, M.

    2009-12-01

    Gravel augmentations are being implemented in a number of streams where natural recruitment of gravel is impeded by dams. Uncertainties relevant to the management of gravel augmentations include the quantities of gravel needed to achieve habitat benefits at downstream locations and the temporal and spatial scales over which those benefits that will be realized. The solution to such questions depends to a large extent on how gravel slugs evolve as the material is transported downstream, i.e., whether the gravel translates downstream as a coherent wave or whether it tends to disperse. A number of recent studies conducted in laboratory flumes or by numerical simulation that gravels slugs tend to disperse rather than translate. However, these studies do not consider the influence of channel morphology on slug behavior. Initial monitoring results based from 2 California streams suggest that natural channel morphology suppresses slug dispersion because the gravel tends to accumulate in discrete deposition zones. Field mapping and about 200 tracer stones implanted with passive integrated transponder (PIT) tags show that gravel recruitment piles of about 80 tons each placed in Grass Valley Creek in 2007 and 2008 were deposited as 2 new bars immediately downstream. The more upstream of the 2 bars formed during the 2007 winter and spring flood season, whereas the more downstream bar did not appear until the following year. A sharp deposition front and an absence of tracers in the reaches downstream strongly suggest that none of the added gravel was transported downstream beyond the area of bar formation in either year. A relatively small proportion of the mobilized tracer particles (59%) were located following the 2007 flood season, probably due to deep burial in the newly deposited bar and to radio interference caused by the high concentration of tracers in a small area. The proportion of newly introduced or previously-located tracers that were relocated in 2009 was

  10. FANCD2 functions as a critical factor downstream of MiTF to maintain the proliferation and survival of melanoma cells.

    Science.gov (United States)

    Bourseguin, Julie; Bonet, Caroline; Renaud, Emilie; Pandiani, Charlotte; Boncompagni, Marina; Giuliano, Sandy; Pawlikowska, Patrycja; Karmous-Benailly, Houda; Ballotti, Robert; Rosselli, Filippo; Bertolotto, Corine

    2016-11-09

    Proteins involved in genetic stability maintenance and safeguarding DNA replication act not only against cancer initiation but could also play a major role in sustaining cancer progression. Here, we report that the FANC pathway is highly expressed in metastatic melanoma harboring the oncogenic microphthalmia-associated transcription factor (MiTF). We show that MiTF downregulation in melanoma cells lowers the expression of several FANC genes and proteins. Moreover, we observe that, similarly to the consequence of MiTF downregulation, FANC pathway silencing alters proliferation, migration and senescence of human melanoma cells. We demonstrate that the FANC pathway acts downstream MiTF and establish the existence of an epistatic relationship between MiTF and the FANC pathway. Our findings point to a central role of the FANC pathway in cellular and chromosomal resistance to both DNA damage and targeted therapies in melanoma cells. Thus, the FANC pathway is a promising new therapeutic target in melanoma treatment.

  11. Simulation of hydrogen migration and blisters formation in zirconium alloys

    International Nuclear Information System (INIS)

    Saliba, R.O.

    1991-06-01

    The phenomenon of hydrogen migration and hydride blister growth after pressure tube/calandria tube contact in CANDU reactors is addressed. This phenomenon is by now regarded as an important factor limiting reactors lifetime, since it originated Pickering incident in 1983. Numerical results of thermally-assisted diffusion in excellent agreement with quasi-analytical solutions of the mathematical model were obtained. A sensitivity analysis was performed to assess the accuracy of these results. Some two-dimensional calculations are also included to demonstrate the capabilities of the numerical methods. The main outcomes of the work are the following: a through understanding of the mathematics and physics involved in hydrogen migration under thermal gradients. The validation of a numerical procedure based on a regularization of the constitutive equations. Blister growth rates in slab geometries for initial concentrations that span the full range of technological interest. Some preliminary two-dimensional results allow the design of future developments. (Author) [es

  12. Downstream anastomotic hyperplasia. A mechanism of failure in Dacron arterial grafts.

    Science.gov (United States)

    LoGerfo, F W; Quist, W C; Nowak, M D; Crawshaw, H M; Haudenschild, C C

    1983-01-01

    The precise location and progression of anastomotic hyperplasia and its possible relationship to flow disturbances was investigated in femoro-femoral Dacron grafts in 28 dogs. In 13 grafts, the outflow from the end-to-side downstream anastomosis was bidirectional (BDO), and in 15 it was unidirectional (UDO) (distally). Grafts were electively removed at intervals of two to 196 days or at the time of thrombosis. Each anastomosis and adjacent artery was perfusion-fixed and sectioned sagittally. The mean sagittal section was projected onto a digitized pad, and the total area of hyperplasia internal to the arterial internal elastic lamina and within the adjacent graft was integrated by computer. The location of the hyperplasia was compared with previously established sites of flow separation and stagnation. The observation was made that hyperplasia is significantly greater at the downstream, as compared with the upstream, anastomosis in both groups (BDO = p less than 0.001 and UDO = p less than 0.001) (analysis of variance for independent groups). Furthermore, this downstream hyperplasia was progressive with time (BDO p less than 0.01) (UDO p less than 0.01); Spearman Rank Correlation. There was no significant increase in the extent of downstream hyperplasia where flow separation was known to be greater (BDO). Five grafts failed (three BDO, two UDO), as a result of complete occlusion of the downstream anastomosis by fibrous hyperplasia. Transmission electron microscopy showed the hyperplasia to consist of collagen-producing smooth muscle cells. Anastomotic hyperplasia is significantly greater at the downstream anastomosis, is progressive with time, and is the primary cause of failure of Dacron arterial grafts in this model. Quantitative analysis of downstream anastomotic hyperplasia may be a valuable measure of the biocompatibility of Dacron grafts. Images Fig. 2. Fig. 3. Fig. 5. Fig. 6. Fig. 7. Fig. 8. PMID:6219641

  13. [International migration in the Middle East].

    Science.gov (United States)

    Beauge, G

    1985-01-01

    This special issue contains a selection of 12 papers by various authors on aspects of international migration to the Middle East. Papers are included on the impact of migration on socioeconomic development, income distribution, and rural capitalization in Egypt; migration from rural Lebanon; the effect of emigration on Pakistan; Indian workers in Oman; inter-Arab migration and development; the role of the state in migration in the Arab peninsula; the dynamics of manpower in Kuwait; the Iraqi model and Arab unity; and the impact of this migration on the concept of the New Economic Order.

  14. Labour Force Migration Effects within European Union

    Directory of Open Access Journals (Sweden)

    Carmen Mihaela Tudorache

    2006-10-01

    Full Text Available Within the EU, there is no common policy on migration; there are common policies on certain aspects of migration. The Member States fear of migration, but their economies and societies will further need migrant workers. Labour force migration have positive, but also negative consequences for all parties involved: receiving countries, origin countries and migrant workers. Within this framework, a common approach of the migration management and the harmonization of the economic migration policies of the Member States represent already one of the most important challenges for the European Union and will be further emphasized.

  15. Measuring attitudes towards unauthorized migration

    NARCIS (Netherlands)

    van der Veer, C.G.; Ommundsen, R.; Krumov, K.; Van Le, H.; Larsen, K.S.

    2008-01-01

    This study reports on the development and cross-national utility of a Likert type scale measuring attitudes toward unauthorized migration into a foreign country in two samples from "migrant-sending" nations. In the first phase a pool of 86 attitude statements were administered to a sample of 505

  16. Convergence and migration among provinces.

    Science.gov (United States)

    Helliwell, J F

    1996-04-01

    "Have regional disparities in Canada changed over the past thirty years? This paper assesses the robustness of earlier findings of convergence in the levels and growth rates of provincial per capita GDP, and then estimates the extent to which interprovincial and international migration is being influenced by regional differences in incomes and employment." excerpt

  17. Job Migration: A Collaborative Effort

    Science.gov (United States)

    Wagoner, Cynthia L.

    2012-01-01

    Music teachers often change jobs several times during their careers. Reasons for job changes vary, but regardless, these changes bring a different set of challenges. Sharing knowledge and learning are part and parcel of collaboration. So what if, as education professionals, music teachers decided to collaborate during job migrations? For all music…

  18. Migration monitoring with automated technology

    Science.gov (United States)

    Rhonda L. Millikin

    2005-01-01

    Automated technology can supplement ground-based methods of migration monitoring by providing: (1) unbiased and automated sampling; (2) independent validation of current methods; (3) a larger sample area for landscape-level analysis of habitat selection for stopover, and (4) an opportunity to study flight behavior. In particular, radar-acoustic sensor fusion can...

  19. [Migration of dentists within Hungary].

    Science.gov (United States)

    Balázs, Péter

    2010-09-01

    Concerning the human resource management in the health care, Hungarian analysts focus mainly on cross-national migration, which was instigated considerably by joining the European Union in 2004. Contrasted to other health care professionals, dentists emphasized also the importance of in-country migration (mobility) indicating serious dangers of developing inequalities in the dental service. From the point of view of health system planning, the main problem is to balance the needs and the number of professionals in regions and areas with extremely different socio-economic conditions. Under dictatorial governments, this "balancing" (which was experienced also in Hungary) is a forced allocation of young professionals to the target regions. In political freedom and free market economy, these measures are unthinkable. The present domestic area distribution, concerning also the supply through vacancies by old age inactivity and cross-national migration, is ruled by personal decisions of actually graduated and immigrant professionals respectively. Therefore, it is unavoidable to investigate the interrelation of factors (dentists' births place, study migration and decisions for practice allocation) ruling the in-country geographic patterns of dental practices. This evidence-based knowledge can only explain the present situation and provide guidelines for health policy decision makers.

  20. Liquid chromatography in migration studies

    International Nuclear Information System (INIS)

    Carlsen, L.; Batsberg, W.

    1982-01-01

    Liquid chromatography ahs been suggested as a facile experimental technique to determine important physico-chemical properties, as permeability, porosity, dispersion-, diffusion-, and sorption charcteristics for geological material as chalk samples. The feasibility of the trechnique as a rapid method to evaluate the possible influence of changes in ground water composition on the migration behavior of radionuclides has been demonstrated

  1. Marriage migration in the Netherlands

    NARCIS (Netherlands)

    Leen Sterckx; Jaco Dagevos; Willem Huijnk; Jantine van Lisdonk

    2014-01-01

    Original title: Huwelijksmigratie in Nederland When a man or woman living in the Netherlands embarks on a relationship with a partner from another country and the couple decide to build a married life together in the Netherlands, we call this marriage migration. The foreign partner who moves to

  2. Migration of accreting giant planets

    Science.gov (United States)

    Crida, A.; Bitsch, B.; Raibaldi, A.

    2016-12-01

    We present the results of 2D hydro simulations of giant planets in proto-planetary discs, which accrete gas at a more or less high rate. First, starting from a solid core of 20 Earth masses, we show that as soon as the runaway accretion of gas turns on, the planet is saved from type I migration : the gap opening mass is reached before the planet is lost into its host star. Furthermore, gas accretion helps opening the gap in low mass discs. Consequently, if the accretion rate is limited to the disc supply, then the planet is already inside a gap and in type II migration. We further show that the type II migration of a Jupiter mass planet actually depends on its accretion rate. Only when the accretion is high do we retrieve the classical picture where no gas crosses the gap and the planet follows the disc spreading. These results impact our understanding of planet migration and planet population synthesis models. The e-poster presenting these results in French can be found here: L'e-poster présentant ces résultats en français est disponible à cette adresse: http://sf2a.eu/semaine-sf2a/2016/posterpdfs/156_179_49.pdf.

  3. [Haitian migration to Santo Domingo].

    Science.gov (United States)

    Latortue, P R

    1985-01-01

    This work examines the history of Haitian migration to the Dominican Republic, the central role of Haitian migration in Dominican society, working conditions of Haitian migrants in the Dominican Republic, and the relationship of the migration to economic development on the island of Hispaniola. Lack of data, the difficulty of measuring illegal movement, and the problem of defining Haitians in Santo Domingo have impeded understanding of migration to the Dominican Republic. It is believed by many authorities that Haitian migration to Santo Domingo is considerable and perhaps exceeds that to the US. Haitian migration to the Dominican Republic began after 1915 with the fall of the Haitian president, a worsening of economic conditions partly caused by stagnation in the agricultural sector, and the newly dominant role of the US in Haitian economic affairs. The Great Depression of the 1930s was a direct antecedent of the massacre of Haitians by Dominican police in which some 30 thousand persons were killed; the economic recession of the early 1980s has also caused an outburst of antiHaitian feeling in the Dominican Republic although 80% of laborers in the sugar industry are Haitians. Sugar is extremely important to the Dominican economy: in 1974, sugar covered 12% of cultivated land, produced 40% of foreign exchange earnings, and was responsable for 21% of taxable income. Dominicans however refuse to work in sugar plantations under the current technological. conditions and wage system. Although the government periodically demands the Dominicanization of the sugar work force, no such changes have been made. Sugar will probably continue to play a decisive role in the generation of foreign exchange despite introduction of more technologically advanced sectors which benefit from better prices in the international market. Possibilities of mechanizing sugar production in the Dominican Republic appear remote, and failure to modernize an important sector of the economy has

  4. Sedimentary record of erg migration

    Science.gov (United States)

    Porter, M. L.

    1986-06-01

    The sedimentary record of erg (eolian sand sea) migration consists of an idealized threefold division of sand-sea facies sequences. The basal division, here termed the fore-erg, is composed of a hierarchy of eolian sand bodies contained within sediments of the flanking depositional environment. These sand bodies consist of eolian strata deposited by small dune complexes, zibars, and sand sheets. The fore-erg represents the downwind, leading edge of the erg and records the onset of eolian sedimentation. Basin subsidence coupled with erg migration places the medial division, termed the central erg, over the fore-erg strata. The central erg, represented by a thick accumulation of large-scale, cross-stratified sandstone, is the product of large draa complexes. Eolian influence on regional sedimentation patterns is greatest in the central erg, and most of the sand transported and deposited in the erg is contained within this region. Reduction in sand supply and continued erg migration will cover the central-erg deposits with a veneer of back-erg deposits. This upper division of the erg facies sequence resembles closely the fore-erg region. Similar types of eolian strata are present and organized in sand bodies encased in sediments of the upwind flanking depositional environment(s). Back-erg deposits may be thin due to limited eolian influence on sedimentation or incomplete erg migration, or they may be completely absent because of great susceptibility to postdepositional erosion. Tectonic, climatic, and eustatic influences on sand-sea deposition will produce distinctive variations or modifications of the idealized erg facies sequence. The resulting variants in the sedimentary record of erg migration are illustrated with ancient examples from western North America, Europe, southern Africa, and South America.

  5. [Migration patterns of health professionals].

    Science.gov (United States)

    Kingma, Mireille

    2005-01-01

    The past three decades have seen the number of international migrants double, to reach the unprecedented total of 175 million people in 2003. National health systems are often the biggest national employer, responsible for an estimated 35 million workers worldwide. Health professionals are part of the expanding global labour market. Today, foreign-educated health professionals represent more than a quarter of the medical and nursing workforces of Australia, Canada, the United Kingdom and the United States. Destination countries, however, are not limited to industrialised nations. For example, 50 per cent of physicians in the Namibia public services are expatriates and South Africa continues to recruit close to 80% of its rural physicians from other countries. International migration often imitates patterns of internal migration. The exodus from rural to urban areas, from lower to higher income urban neighbourhoods and from lower-income to higher-income sectors contributes challenges to the universal coverage of the population. International migration is often blamed for the dramatic health professional shortages witnessed in the developing countries. A recent OECD study, however, concludes that many registered nurses in South Africa (far exceeding the number that emigrate) are either inactive or unemployed. These dire situations constitute a modern paradox which is for the most part ignored. Shared language, promises of a better quality of life and globalization all support the continued existence of health professionals' international migration. The ethical dimension o this mobility is a sensitive issue that needs to be addressed. A major paradigm shift, however, is required in order to lessen the need to migrate rather than artificially curb the flows.

  6. Mediterranean Migrations: Regionalisms Versus Globalisation

    Directory of Open Access Journals (Sweden)

    Martin Baldwin-Eduards

    2004-06-01

    Full Text Available This paper challenges the claim of globalisation as a cause ofimmigration into Southern Europe and, on an empirical basis, identifies regionalisation as being the primary issue, along with networked migratory patterns. However, the changing patterns of immigration do present challenges to both state and society. It is argued here that recent policy responses in Portugal, Italy and Spain have been inconsistent and irrational – reflecting more the ‘securitisation’ of migration than European reality. Earlier policy innovations are identified, by country and date: most of these have now been abandoned. It is suggested that all of Southern Europe has converged onto a statist, restrictionist model of immigration control that was formerly held only by Greece. The principal characteristics of this model are outlined, along with a migration flowchart and indicative data for migrant flows and sub-flows in Italy and Spain. In the final section, I try to show that the needs of the economy cannot be predicted, immigration cannot becontrolled in the manner currently being enforced across Southern Europe, and attempts to do so will damage rather than improve economic productivity and growth. The concept of an accomodating immigration policy is advanced, whereby the state tries to manage the needs of both employers and potential migrants. Six guidelines for policy development are suggested – most of which have alreadybeen successfully carried out in the European Union. These are the following: migration in order to find a job; circular cross-border migration; EU level negotiation of readmission agreements; the need for a variety of migration-for-employment schemes; legal residence should not depend upon continuity of employment; and discreet legalisation will still be needed in Southern Europe.

  7. Innovative water withdrawal system re-establishes fish migration runs

    International Nuclear Information System (INIS)

    Anon.

    2008-01-01

    This article described a unique water withdrawal and fish bypass structure that is under construction in Oregon to re-establish anadromous fish runs and to improve water quality downstream of the Round Butte dam. Portland General Electric and the Confederated Tribes of the Warm Springs Reservation, which co-own the dam, have committed to re-establish fish runs in response to concerns over the declining numbers of salmon and trout in the region. Water intakes are routinely added at hydroelectric facilities to protect native fish in compliance with the Federal Energy Regulatory Commission and the Clean Water Act. The Round Butte Hydroelectric project had a complex set of challenges whereby surface-current directions had to be changed to help migrating salmon swim easily into a fish handling area and create a fish collection system. CH2M HILL designed the system which consists of a large floating structure, an access bridge, a large vertical conduit and a base structure resting on the lake bed. Instead of using 2D CAD file methods, CH2M HILL decided to take advantage of 3D models to visualize the complex geometry of these structures. The 3D models were used to help designers and consultants understand the issues, resolve conflicts and design solutions. The objective is to have the system operating by the 2009 migrating season. 1 ref., 4 figs

  8. Synthesis of juvenile lamprey migration and passage research and monitoring at Columbia and Snake River Dams

    Science.gov (United States)

    Mesa, Matthew G.; Weiland, Lisa K.; Christiansen, Helena E.

    2016-01-01

    We compiled and summarized previous sources of data and research results related to the presence, numbers, and migration timing characteristics of juvenile (eyed macropthalmia) and larval (ammocoetes) Pacific lamprey Entosphenus tridentatus, in the Columbia River basin (CRB). Included were data from various screw trap collections, data from historic fyke net studies, catch records of lampreys at JBS facilities, turbine cooling water strainer collections, and information on the occurrence of lampreys in the diets of avian and piscine predators. We identified key data gaps and uncertainties that should be addressed in a juvenile lamprey passage research program. The goal of this work was to summarize information from disparate sources so that managers can use it to prioritize and guide future research and monitoring efforts related to the downstream migration of juvenile Pacific lamprey within the CRB. A common finding in all datasets was the high level of variation observed for CRB lamprey in numbers present, timing and spatial distribution. This will make developing monitoring programs to accurately characterize lamprey migrations and passage more challenging. Primary data gaps centered around our uncertainty on the numbers of juvenile and larval present in the system which affects the ability to assign risk to passage conditions and prioritize management actions. Recommendations include developing standardized monitoring methods, such as at juvenile bypass systems (JBS’s), to better document numbers and timing of lamprey migrations at dams, and use biotelemetry tracking techniques to estimate survival potentials for different migration histories.

  9. Glutathione S-transferase P influences redox and migration pathways in bone marrow.

    Directory of Open Access Journals (Sweden)

    Jie Zhang

    Full Text Available To interrogate why redox homeostasis and glutathione S-transferase P (GSTP are important in regulating bone marrow cell proliferation and migration, we isolated crude bone marrow, lineage negative and bone marrow derived-dendritic cells (BMDDCs from both wild type (WT and knockout (Gstp1/p2(-/- mice. Comparison of the two strains showed distinct thiol expression patterns. WT had higher baseline and reactive oxygen species-induced levels of S-glutathionylated proteins, some of which (sarco-endoplasmic reticulum Ca2(+-ATPase regulate Ca(2+ fluxes and subsequently influence proliferation and migration. Redox status is also a crucial determinant in the regulation of the chemokine system. CXCL12 chemotactic response was stronger in WT cells, with commensurate alterations in plasma membrane polarization/permeability and intracellular calcium fluxes; activities of the downstream kinases, ERK and Akt were also higher in WT. In addition, expression levels of the chemokine receptor CXCR4 and its associated phosphatase, SHP-2, were higher in WT. Inhibition of CXCR4 or SHP2 decreased the extent of CXCL12-induced migration in WT BMDDCs. The differential surface densities of CXCR4, SHP-2 and inositol trisphosphate receptor in WT and Gstp1/p2(-/- cells correlated with the differential CXCR4 functional activities, as measured by the extent of chemokine-induced directional migration and differences in intracellular signaling. These observed differences contribute to our understanding of how genetic ablation of GSTP causes different levels of myeloproliferation and migration [corrected

  10. Migrating swans profit from favourable changes in wind conditions at low altitude

    NARCIS (Netherlands)

    Klaassen, M; Beekman, JH; Kontiokorpi, J; Mulder, RJW; Nolet, BA

    Because energy reserves limit flight range, wind assistance may be of crucial importance for migratory birds. We tracked eight Bewick's swans Cygnus columbianus bewickii, using 95-g satellite transmitters with altimeters and activity sensors, during their spring migration from Denmark to northern

  11. Migrating swans profit from favourable changes in wind conditions at low altitude

    NARCIS (Netherlands)

    Klaassen, M.R.J.; Beekman, J.H.; Kontiokorpi, J.; Mulder, R.J.W.; Nolet, B.A.

    2004-01-01

    Because energy reserves limit flight range, wind assistance may be of crucial importance for migratory birds. We tracked eight Bewicks swans Cygnus columbianus bewickii, using 95-g satellite transmitters with altimeters and activity sensors, during their spring migration from Denmark to northern

  12. Analytical prediction of the unsteady lift on a rotor caused by downstream struts

    Science.gov (United States)

    Taylor, A. C., III; Ng, W. F.

    1987-01-01

    A two-dimensional, inviscid, incompressible procedure is presented for predicting the unsteady lift on turbomachinery blades caused by the upstream potential disturbance of downstream flow obstructions. Using the Douglas-Neumann singularity superposition potential flow computer program to model the downstream flow obstructions, classical equations of thin airfoil theory are then employed, to compute the unsteady lift on the upstream rotor blades. The method is applied to a particular geometry which consists of a rotor, a downstream stator, and downstream struts which support the engine casing. Very good agreement between the Douglas-Neumann program and experimental measurements was obtained for the downstream stator-strut flow field. The calculations for the unsteady lift due to the struts were in good agreement with the experiments in showing that the unsteady lift due to the struts decays exponentially with increased axial separation of the rotor and the struts. An application of the method showed that for a given axial spacing between the rotor and the strut, strut-induced unsteady lift is a very weak function of the axial or circumferential position of the stator.

  13. Depth migration and de-migration for 3-D migration velocity analysis; Migration profondeur et demigration pour l'analyse de vitesse de migration 3D

    Energy Technology Data Exchange (ETDEWEB)

    Assouline, F.

    2001-07-01

    3-D seismic imaging of complex geologic structures requires the use of pre-stack imaging techniques, the post-stack ones being unsuitable in that case. Indeed, pre-stack depth migration is a technique which allows to image accurately complex structures provided that we have at our disposal a subsurface velocity model accurate enough. The determination of this velocity model is thus a key element for seismic imaging, and to this end, migration velocity analysis methods have met considerable interest. The SMART method is a specific migration velocity analysis method: the singularity of this method is that it does not rely on any restrictive assumptions on the complexity of the velocity model to determine. The SMART method uses a detour through the pre-stack depth migrated domain for extracting multi-offset kinematic information hardly accessible in the time domain. Once achieved the interpretation of the pre-stack depth migrated seismic data, a kinematic de-migration technique of the interpreted events enables to obtain a consistent kinematic database (i.e. reflection travel-times). Then, the inversion of these travel-times, by means of reflection tomography, allows the determination of an accurate velocity model. To be able to really image geologic structures for which the 3-D feature is predominant, we have studied the implementation of migration velocity analysis in 3-D in the context of the SMART method, and more generally, we have developed techniques allowing to overcome the intrinsic difficulties in the 3-D aspects of seismic imaging. Indeed, although formally the SMART method can be directly applied to the case of 3-D complex structures, the feasibility of its implementation requires to choose well the imaging domain. Once this choice done, it is also necessary to conceive a method allowing, via the associated de-migration, to obtain the reflection travel-times. We first consider the offset domain which constitutes, still today, the strategy most usually used

  14. KIN NETWORKS AND MIGRATION IN SAGBAMA LOCAL ...

    African Journals Online (AJOL)

    CIU

    Historically, migration process has been characterized and continues to be .... Mexican migration to the U.S (Massey, Arango, Hugo, Kouaouci, Pellegrino and .... the study destination (Sagbama) according to Independent National Electoral.

  15. Comparative Political Economy and International Migration

    NARCIS (Netherlands)

    Afonso, A.; Devitt, C.

    2016-01-01

    This article provides an overview of the literature connecting comparative political economy and international migration in advanced industrialized countries with a focus on the relationship between labour migration, labour markets and welfare institutions. Immigration flows and policies are

  16. Individual Decisions to Migrate During Civil Conflict

    Science.gov (United States)

    Bohra-Mishra, Pratikshya; Massey, Douglas S.

    2012-01-01

    The existing literature on forced migration limits our understanding of how violence affects migration to competing destinations. This article adds to the literature on forced migration by studying how armed violence during a period of civil conflict in south-central Nepal influenced the likelihood of local, internal, and international migration. We find that violence has a nonlinear effect on migration, such that low to moderate levels of violence reduce the odds of movement, but when violence reaches high levels, the odds of movement increase. We also find that the effect of violence on mobility increases as the distance of the move increases. When we consider the influence of violence on microlevel decision-making, we find that the effects of individual and household-level determinants were mostly consistent with hypotheses derived from contemporary theories of voluntary migration and that no predictor of migration influenced the decision to migrate differently in the presence of violence. PMID:21541805

  17. Migration aspirations and migration cultures : A case study of Ukrainian migration towards the European Union

    NARCIS (Netherlands)

    Van Mol, C.; Snel, Erik; Hemmerechts, Kenneth; Timmerman, Christiane

    2018-01-01

    An abundant body of research focused on macrolevel, mesolevel, and microlevel factors explaining why individuals move across international borders. In this paper, we aim to complement the existing literature by exploring how, within a single country, mesolevel factors differently impact migration

  18. Nanoparticles migration in fractured rocks and affects on contaminant migration

    Science.gov (United States)

    Missana, Tiziana; Garcia-Gutierrez, Miguel; Alonso, Ursula

    2014-05-01

    In previous studies, the transport behavior of artificial (gold and latex) and natural (smectite clay) colloids, within a planar fracture in crystalline rock, was analyzed. In order to better understand the effects of colloid size, shape and surface charge on nanoparticle migration and especially on filtration processes on natural rock surfaces, different clay colloids and oxide nanoparticles were selected and their transport studied as a function of the residence time. In all the cases, (a fraction of) the nanoparticles travelled in the fracture as fast as or faster than water (with a retardation factor, Rf ≤ 1) and the observed Rf, was related to the Taylor dispersion coefficient, accounting for colloid size, water velocity and fracture width. However, under most of the cases, in contrast to the behavior of a conservative tracer, colloids recovery was much lower than 100 %. Differences in recovery between different nanoparticles, under similar residence times, were analyzed. In order to evaluate the possible consequences, on contaminant migration, of the presence of nanoparticles in the system, transport tests were carried out with both colloids and sorbing radionuclides. The overall capacity for colloids of enhancing radionuclide migration in crystalline rock fractures is discussed. Acknowledgments: The research leading to these results received funding from EU FP7/2007-2011 grant agreement Nº 295487 (BELBAR, Bentonite Erosion: effects on the Long term performance of the engineered Barrier and Radionuclide Transport) and by the Spanish Government under the project NANOBAG (CTM2011-2797).

  19. Migration and Remittances Factbook 2016, Third Edition

    OpenAIRE

    World Bank Group

    2016-01-01

    The Migration and Remittances Factbook 2016 attempts to present numbers and facts behind the stories of international migration and remittances, drawing on authoritative, publicly available data. It provides a snapshot of statistics on immigration, emigration, skilled emigration, and remittance flows for 210 countries and 15 regional and income groups. The Migration and Remittances Factbook 2016 updates the 2011 edition of the Factbook with additional data on bilateral migration and remittanc...

  20. Capitalist development and internal migration in Nigeria.

    Science.gov (United States)

    Akor, R I; Mou, D

    1986-12-01

    The authors analyze internal migration trends in Nigeria by examining individual household strategies and how they have adapted to structural changes brought about by colonial rule and capitalist development. The first section of this article describes the structural changes that started the process of labor migration. The second section deals with post-independence industrialization and the consequent rural-urban migration. The final section analyzes the consequences of these migration patterns for urban growth and rural productivity.

  1. Globalization and formal sector migration in Brazil

    OpenAIRE

    Aguayo-Tellez, Ernesto; Muendler, Marc-Andreas; Poole, Jennifer Pamela

    2008-01-01

    We use novel linked employer–employee data to study the relationship between globalization and formal sector interstate migration for Brazil. We estimate the worker’s multichoice migration problem and document that previously unobserved employer covariates are significant predictors associated with migration flows. Our results provide support for the idea that globalization acts on internal migration through the growth of employment opportunities at locations with a high concentration of fore...

  2. An experimental study on downstream of the transition of the chemically reacting liquid round free jet

    International Nuclear Information System (INIS)

    Hong, S.D.; Sugii, Y.; Okamoto, K.; Madarame, H.

    2002-01-01

    An experimental study was conducted on the chemically reacting liquid round free jet, Laser Induced Fluorescence (LIF) technique was adopted to evaluate the diffusion width of the jet into liquid streams. In the fluid engineering, it is very important to evaluate the characteristics of reacting jet for the safety of the nuclear reactor. In this study, the jet profile of downstream region far away from the transition point was evaluated, providing comparisons between reacting and non-reacting jet case. The concentration of the jet solution was varied from 0.01 mol/L to 0.5 mol/L in reacting cases. In the downstream far away from the transition point, the jet profiles between reacting cases and non-reacting cases were visualized quite different. It was concluded that the chemical reaction affects the momentum diffusion of the jet in the downstream region. (author)

  3. Juridical structures: refugees and migration.

    Science.gov (United States)

    Veiter, T

    1988-01-01

    The juridical problems in regard to the concepts of refugee, expulsion, and migration are complicated. If one speaks about migration in Europe, one must 1st distinguish between Eastern and Western Europe. In the communist states of Eastern Europe the refugee problem does not exist officially, with the only existing refugee problem in Yugoslavia, which has signed and ratified the Geneva Refugee Convention of 1951. In the other East European states the right to asylum exists, but refugees are granted asylum only if they are persecuted in their country of origin for their communist ideas and activities. In speaking of migration, one must distinguish between migration, forced migration, mass migration, emigration, immigration, the shift of populations, and refugees. In the communist countries of Eastern Europe the right to emigration is not respected, although certain exceptions, as in Poland or Yugoslavia do exist. Generally, in the communist states emigration is not allowed and illegal emigration is punished as "Flight from the Republic." With a few exceptions, political and other persecutions are no longer so typical within Europe. In the last decades, the refugee problem has changed to other continents: Afghanistan/Pakistan, Iran, Sri Lanka, East Timor, Lebanon, Palestine, Sudan, Tchad, Ethiopia, Eritrea, and Angola. The refugee problem in Europe consists mainly in the large afflux of refugees coming from places with other cultural (and religious) attributes. The Islamic immigrants declare themselves regularly as political refugees and hope to be acknowledged as such by the receiving state. The fear of the governments and populations of the receiving countries is that it would not be possible to assimilate such aliens who do not belong to the Christian culture of Europe. Formerly, refugees came mostly from the Christian countries of Eastern Europe with the same race identity and the same religion. For years now, more and more foreign workers are a kind of migrant

  4. Assisted Vaginal Delivery

    Science.gov (United States)

    ... Education & Events Advocacy For Patients About ACOG Assisted Vaginal Delivery Home For Patients Search FAQs Assisted Vaginal ... Vaginal Delivery FAQ192, February 2016 PDF Format Assisted Vaginal Delivery Labor, Delivery, and Postpartum Care What is ...

  5. Photoperiod control of downstream movements of Atlantic salmon Salmo salar smolts

    Science.gov (United States)

    Zydlewski, Gayle B.; Stich, Daniel S.; McCormick, Stephen D.

    2014-01-01

    This study provides the first direct observations that photoperiod controls the initiation of downstream movement in Atlantic salmon Salmo salar smolts. Under simulated natural day length (LDN) conditions and seasonal increases in temperature, smolts increased their downstream movements five-fold for a period of 1 month in late spring. Under the same conditions, parr did not show changes in downstream movement behaviour. When given a shortened day length (10L:14D) beginning in late winter, smolts did not increase the number of downstream movements. An early increase in day length (16L:8D) in late winter resulted in earlier initiation and termination of downstream movements compared to the LDN group. Physiological status and behaviour were related but not completely coincident: gill Na+/K+-ATPase activity increased in all treatments and thyroid hormone was elevated prior to movement in 16L:8D treatment. The most parsimonious model describing downstream movement of smolts included synergistic effects of photoperiod treatment and temperature, indicating that peak movements occurred at colder temperatures in the 16L:8D treatment than in LDN, and temperature did not influence movement of smolts in the 10L:14D treatment. The complicated interactions of photoperiod and temperature are not surprising since many organisms have evolved to rely on correlations among environmental cues and windows of opportunity to time behaviours associated with life-history transitions. These complicated interactions, however, have serious implications for phenological adjustments and persistence ofS. salar populations in response to climate change.

  6. [Urban employment and internal migration in Peru].

    Science.gov (United States)

    Cotlear, D

    1984-06-01

    The relationship between internal migration and employment problems in Peru is examined. The author argues that regional differences in income distribution are the primary causes of migration, particularly to urban areas. A model of the migration process is developed and tested using data from official sources, surveys, and the published literature.

  7. QUALIFIED VERSION OF MIGRATION: BRAIN DRAIN

    OpenAIRE

    Ayhan GENCLER

    2009-01-01

    Though globalization suggests an international exchange of people besides goods and capital, developed countries often tended to put forward some restrictions on the migration of workers from developed countries. However, there has been an increase in skilled international migration especially during the last two decades. Skilled international migration or brain drain points out the emigration of educated and highly skilled workers. It seems tha...

  8. Migration Flows: Measurement, Analysis and Modeling

    NARCIS (Netherlands)

    Willekens, F.J.; White, Michael J.

    2016-01-01

    This chapter is an introduction to the study of migration flows. It starts with a review of major definition and measurement issues. Comparative studies of migration are particularly difficult because different countries define migration differently and measurement methods are not harmonized.

  9. Canine assisted reading

    OpenAIRE

    Sever, Jerneja

    2016-01-01

    The diploma thesis presents various aspects of animals included in animal-assisted interventions. In theoretical part, I introduced different possible ways of animal-assisted interventions: animal-assisted therapy, animal-assisted activities and animal-assisted education. Animals became common visitors in educational settings all over the world. I presented positive influences on various aspects of human life, as well limitations when animal-assisted interventions are not possible to perform ...

  10. Downstream-Conditioned Maximum Entropy Method for Exit Boundary Conditions in the Lattice Boltzmann Method

    Directory of Open Access Journals (Sweden)

    Javier A. Dottori

    2015-01-01

    Full Text Available A method for modeling outflow boundary conditions in the lattice Boltzmann method (LBM based on the maximization of the local entropy is presented. The maximization procedure is constrained by macroscopic values and downstream components. The method is applied to fully developed boundary conditions of the Navier-Stokes equations in rectangular channels. Comparisons are made with other alternative methods. In addition, the new downstream-conditioned entropy is studied and it was found that there is a correlation with the velocity gradient during the flow development.

  11. Recent hydrocarbon developments in Latin America: Key issues in the downstream oil sector

    International Nuclear Information System (INIS)

    Wu, K.; Pezeshki, S.

    1995-01-01

    This report discusses the following: (1) An overview of major issues in the downstream oil sector, including oil demand and product export availability, the changing product consumption pattern, and refineries being due for major investment; (2) Recent upstream developments in the oil and gas sector in Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Mexico, Peru, Trinidad and Tobago, and Venezuela; (3) Recent downstream developments in the oil and gas sector in Argentina, Chile, Colombia, Ecuador, Mexico, Peru, Cuba, and Venezuela; (4) Pipelines in Argentina, Bolivia, Brazil, Chile, and Mexico; and (5) Regional energy balance. 4 figs., 5 tabs

  12. Estimating Subcatchment Runoff Coefficients using Weather Radar and a Downstream Runoff Sensor

    DEFF Research Database (Denmark)

    Ahm, Malte; Thorndahl, Søren Liedtke; Rasmussen, Michael R.

    2013-01-01

    This paper presents a method for estimating runoff coefficients of urban drainage subcatchments based on a combination of high resolution weather radar data and flow measurements from a downstream runoff sensor. By utilising the spatial variability of the precipitation it is possible to estimate...... the runoff coefficients of the separate subcatchments. The method is demonstrated through a case study of an urban drainage catchment (678 ha) located in the city of Aarhus, Denmark. The study has proven that it is possible to use corresponding measurements of the relative rainfall distribution over...... the catchment and downstream runoff measurements to identify the runoff coefficients at subcatchment level....

  13. Cetuximab insufficiently inhibits glioma cell growth due to persistent EGFR downstream signaling

    DEFF Research Database (Denmark)

    Hasselbalch, Benedikte; Lassen, Ulrik; Poulsen, Hans S

    2010-01-01

    Overexpression and/or amplification of the epidermal growth factor receptor (EGFR) is present in 35-45% of primary glioblastoma multiforme tumors and has been correlated with a poor prognosis. In this study, we investigated the effect of cetuximab and intracellular signaling pathways downstream...... of EGFR, important for cell survival and proliferation. We show insufficient EGFR downregulation and competition with endogenous EGFR ligands upon cetuximab treatment. Dose-response experiments showed inhibition of EGFR phosphorylation without affecting two of the prominent downstream signaling pathways....... Our results indicate that amplification and/or overexpression of EGFR is an unsatisfactory predictor for response to cetuximab....

  14. Recent hydrocarbon developments in Latin America: Key issues in the downstream oil sector

    Energy Technology Data Exchange (ETDEWEB)

    Wu, K.; Pezeshki, S.

    1995-03-01

    This report discusses the following: (1) An overview of major issues in the downstream oil sector, including oil demand and product export availability, the changing product consumption pattern, and refineries being due for major investment; (2) Recent upstream developments in the oil and gas sector in Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Mexico, Peru, Trinidad and Tobago, and Venezuela; (3) Recent downstream developments in the oil and gas sector in Argentina, Chile, Colombia, Ecuador, Mexico, Peru, Cuba, and Venezuela; (4) Pipelines in Argentina, Bolivia, Brazil, Chile, and Mexico; and (5) Regional energy balance. 4 figs., 5 tabs.

  15. Estimating subcatchment runoff coefficients using weather radar and a downstream runoff sensor.

    Science.gov (United States)

    Ahm, Malte; Thorndahl, Søren; Rasmussen, Michael R; Bassø, Lene

    2013-01-01

    This paper presents a method for estimating runoff coefficients of urban drainage subcatchments based on a combination of high resolution weather radar data and flow measurements from a downstream runoff sensor. By utilising the spatial variability of the precipitation it is possible to estimate the runoff coefficients of the separate subcatchments. The method is demonstrated through a case study of an urban drainage catchment (678 ha) located in the city of Aarhus, Denmark. The study has proven that it is possible to use corresponding measurements of the relative rainfall distribution over the catchment and downstream runoff measurements to identify the runoff coefficients at subcatchment level.

  16. Introduction to sump screen downstream effect analysis of AP1000 nuclear power plant

    International Nuclear Information System (INIS)

    Zhang Qinghua; Liu Yu; Chai Guohan

    2010-01-01

    The design of AP1000 takes into account the potential impact of debris clogging on sump screen. In this article, the technical background of sump screen issue and the design characteristics of AP1000 to address the sump screen blockage issue are introduced. The article focuses on the 'downstream effect' analysis method, acceptance criteria and analysis result of AP1000 sump screen. Although the design of AP1000 is different with traditional PWR, the author expects to bring some reference to advance the downstream effect analysis in China through the introduction. (authors)

  17. Migration characteristics and early clinical results of the NANOS® short-stem hip arthroplasty.

    Science.gov (United States)

    Kaipel, Martin; Grabowiecki, Phillip; Sinz, Katrina; Farr, Sebastian; Sinz, Günter

    2015-05-01

    Femoral short stems promise essential advantages in total hip arthroplasty. Up to now, only short- and midterm clinical studies exist. Data on early stem migration that could predict later aseptic loosening at an early stage are rare. The purpose of this study was to assess migration patterns and clinical outcome 2 years after hip replacement by a metaphyseal anchored cementless short stem. Migration data and clinical results were prospectively assessed in 49 patients. Clinical outcome was measured using the Harris Hip Score (HHS). Migration analyses were performed using the computer-assisted Einzel-Bild-Roentgen-Analyse (EBRA) system. At 2 years after surgery, none of the implants needed revision, and HHS increased from 47.9 up to 98.1. Of 49 patients, 5 (10%) showed increased vertical stem migration (1.5 mm/2a) that might predict late aseptic loosening. Of 49 stems, 44 (90%) showed stable migration patterns indicating a beneficial long-term outcome. Results of this study confirm the excellent clinical data of previous works. Migration patterns strongly suggest that short-stem arthroplasty is not only an innovative but also a reliable strategy in total hip replacement.

  18. Japanese Migration and the Americas: An Introduction to the Study of Migration.

    Science.gov (United States)

    Mukai, Gary; Brunette, Rachel

    This curriculum module introduces students to the study of migration, including a brief overview of some categories of migration and reasons why people migrate. As a case study, the module uses the Japanese migration experience in the United States, Peru, Brazil, Canada, Mexico, Argentina, Bolivia, and Paraguay. The module introduces students to…

  19. Nuclide-migration field experiments

    International Nuclear Information System (INIS)

    Erdal, B.R.; Wolfsberg, K.; Johnstone, J.K.; Erickson, K.L.; Friedman, A.M.; Fried, S.; Hines, J.J.

    1981-03-01

    When considering groundwater flow and radionuclide retention in the complex flow systems that can occur in geologic formations, one has a serious problem in determining if laboratory studies are being performed under conditions appropriate to natural systems. This document is the project plan for a program designed to begin to address these problems. The project is being carried out jointly by the Los Alamos National Laboratory, Sandia National Laboratories, and Argonne National Laboratory. The work has three principal objectives: (1) to develop the experimental, instrumental, and safety techniques necessary to conduct controlled, small-scale radionuclide migration field experiments, including those involving actinides; (2) to use these techniques to define radionuclide migration through rock by performing generic, at-depth experiments under closely monitored conditions; and (3) to determine whether available lithologic, geochemical, and hydrologic properties together with existing or developing transport models are sufficient and appropriate to describe real field conditions

  20. MIGRATION OF ORACLE HR DATABASE

    CERN Multimedia

    ais.support@cern.ch

    2001-01-01

    Restricted services from 3 to 7 November 2001 Due to the migration of the Oracle HR application to the Web, some services which rely on the application's availability may be disturbed from Friday 2 November at 17:30 until Thursday 8 November at 08:30. Amongst those services: HR Division: records office, recruitment, claims and benefits. FI Division: personnel accounting, advances and claims. ST Division: registration office (access cards). SPL Division: external firm staff records. EP Division: users' office. Experiments' secretariats: PIE, Greybook. Divisional secretariats: externals, internal addresses. All information concerning this migration is available at: http://ais.cern.ch We apologize for any inconvenience and thank you in advance for your understanding.

  1. Nuclide-migration field experiments

    Energy Technology Data Exchange (ETDEWEB)

    Erdal, B.R.; Wolfsberg, K.; Johnstone, J.K.; Erickson, K.L.; Friedman, A.M.; Fried, S.; Hines, J.J.

    1981-03-01

    When considering groundwater flow and radionuclide retention in the complex flow systems that can occur in geologic formations, one has a serious problem in determining if laboratory studies are being performed under conditions appropriate to natural systems. This document is the project plan for a program designed to begin to address these problems. The project is being carried out jointly by the Los Alamos National Laboratory, Sandia National Laboratories, and Argonne National Laboratory. The work has three principal objectives: (1) to develop the experimental, instrumental, and safety techniques necessary to conduct controlled, small-scale radionuclide migration field experiments, including those involving actinides; (2) to use these techniques to define radionuclide migration through rock by performing generic, at-depth experiments under closely monitored conditions; and (3) to determine whether available lithologic, geochemical, and hydrologic properties together with existing or developing transport models are sufficient and appropriate to describe real field conditions.

  2. Physicists' Forced Migrations under Hitler

    Science.gov (United States)

    Beyerchen, Alan

    2011-03-01

    When the Nazis came to power in early 1933 they initiated formal and informal measures that forced Jews and political opponents from public institutions such as universities. Some physicists retired and others went into industry, but most emigrated. International communication and contact made emigration a viable option despite the desperate economic times in the Great Depression. Another wave of emigrations followed the annexation of Austria in 1938. Individual cases as well as general patterns of migration and adaptation to new environments will be examined in this presentation. One important result of the forced migrations was that many of the physicists expelled under Hitler played important roles in strengthening physics elsewhere, often on the Allied side in World War II.

  3. Migration from India to Australia.

    Science.gov (United States)

    Awasthi, S P; Chandra, A

    1994-01-01

    "The article examines the contemporary trends and future prospects of migration from India to Australia. The focus is on Indian Settlers and Temporary Entrants admitted to Australia for employment and Indian students admitted to Australia for higher studies. The volume of emigration for permanent residence during the early 1990s has made India one of the leading source countries of migration to Australia. A majority of Indians admitted as Settlers every year join the labor force. Recent data indicate that, among Indian Settlers, there is a preponderance of unsponsored Independent Skilled Migrants. Given the anticipated growth in the number of Indian students, the coming years are likely to witness a spurt in Skilled Temporary Workers from India." excerpt

  4. Migration towards Windows 2000/XP

    International Nuclear Information System (INIS)

    Gal, J.

    2004-01-01

    The article deals with interesting technical solutions used in the project 'Migration towards Windows 2000/XP', which was introduced by the company AITEN, Plc for companies SE Plc, SEPS Plc and TEKO, Plc in the period 2002 and 2003. The contents of the project was migration of about 100 servers and more than 4 000 PC to the Windows 2000 and XP environs. The result of the project is a unified and documented system in the field of file, print and small application servers and PC. It has enabled to increase the system reliability and availability, to decrease the total costs for administration and operation and to establish the steady environs for users of the applications. (author)

  5. Blockage of migration routes by dam construction: can migratory fish find alternative routes?

    Directory of Open Access Journals (Sweden)

    Rosimeire Ribeiro Antonio

    Full Text Available The present study explored the interaction between the upriver migration of fish and the blockage of their migration routes by dam construction. Specifically, we studied (i the capacity of migratory fish to locate alternative routes in the presence of an obstacle, and (ii the behavior of the fish after they were artificially transferred to the reservoir. With the use of the mark-recapture technique (tagging, the study was carried out near Porto Primavera Dam (UHE Engenheiro Sérgio Motta between 1994 and 1999, a period prior to the closure of the floodgates and the installation and operation of the fish pass facilities. The fish were caught in the dam forebay downstream, marked with LEA type tags, and released upstream (5113 individuals; 14 species and downstream (1491; 12 from the dam. The recaptures were carried out by local professional and amateur fishermen. A total of 188 individuals (2.8% were recaptured, mostly the curimba Prochilodus lineatus. Nearly half of the recaptures downstream occurred in tributaries, especially in the Paranapanema River, indicating that in the presence of an obstacle the fish are able to locate alternative migration routes. The remainder stayed in the main channel of the Paraná River, at a mean distance of less than 50 km from the release point. Of the fish released upriver from the dam, approximately half were recaptured downriver. Although the river was only partly dammed, the movement of the fish downriver suggests that they became disoriented after being transferred. Those that remained upriver avoided the reservoir and moved, rather rapidly, toward the lotic stretches farther upstream. From these results it is clear that, in the course of the decision process in installing fish passes, it is necessary to take into account the existence of spawning and nursery areas downriver and upriver from the reservoir.

  6. Incentives and disincentives: international migration.

    Science.gov (United States)

    Bhagwati, J N

    1984-01-01

    International migration is largely controlled by disincentives, or quotas, on immigration rather than checks on emigrations. Societies generally feel they have a right to exclude others from their boundaries, but they also usually feel that they do not have a right to control emigration. The single-planetary approach holds that people have the right to live wherever they like on the planet, and the cosmopolitan-utilitarian approach believes the same for reasons of world efficiency. The current feeling that societies have the right to exclude others may be explained best by territoriality in human animals. People also believe that their culture will be diluted if too many outsiders enter. In many cases, immigration systems cannot really control immigration, as in the cases of long landlocked borders between the US and Mexico and between Bangladesh and Assam. Immigration systems also contain legal loopholes. For example, in the US it is easier to get a student visa and convert to immigrant status than to gain immigrant status directly. Loopholes lead to plugs, which lead in turn to more loopholes. An upsurge in requests for political asylum followed increased restrictions on immigration in Western Europe. The US has investigated foreign aid and foreign investments to Mexico and Haiti to curb the flow of illegal migrants. The author suggests that foreign investments may lead to more migration because of the creation of a new proletariat used to the ways of developed countries. An estimate of what would happen if all immigration control were removed worldwide concludes that efficiency and income distribution would improve worldwide. Most migration from developing to developed countries currently consists of the migration of skilled professionals, the brain drain. The author proposes a tax on these professionals to be paid to the country of origin to compensate them for the loss in education and training. The author summarizes the differences between the West German

  7. Elongation factor 1 alpha1 and genes associated with Usher syndromes are downstream targets of GBX2.

    Directory of Open Access Journals (Sweden)

    David A Roeseler

    Full Text Available Gbx2 encodes a DNA-binding transcription factor that plays pivotal roles during embryogenesis. Gain-and loss-of-function studies in several vertebrate species have demonstrated a requirement for Gbx2 in development of the anterior hindbrain, spinal cord, inner ear, heart, and neural crest cells. However, the target genes through which GBX2 exerts its effects remain obscure. Using chromatin immunoprecipitation coupled with direct sequencing (ChIP-Seq analysis in a human prostate cancer cell line, we identified cis-regulatory elements bound by GBX2 to provide insight into its direct downstream targets. The analysis revealed more than 286 highly significant candidate target genes, falling into various functional groups, of which 51% are expressed in the nervous system. Several of the top candidate genes include EEF1A1, ROBO1, PLXNA4, SLIT3, NRP1, and NOTCH2, as well as genes associated with the Usher syndrome, PCDH15 and USH2A, and are plausible candidates contributing to the developmental defects in Gbx2(-/- mice. We show through gel shift analyses that sequences within the promoter or introns of EEF1A1, ROBO1, PCDH15, USH2A and NOTCH2, are directly bound by GBX2. Consistent with these in vitro results, analyses of Gbx2(-/- embryos indicate that Gbx2 function is required for migration of Robo1-expressing neural crest cells out of the hindbrain. Furthermore, we show that GBX2 activates transcriptional activity through the promoter of EEF1A1, suggesting that GBX2 could also regulate gene expression indirectly via EEF1A. Taken together, our studies show that GBX2 plays a dynamic role in development and diseases.

  8. ILLEGAL MIGRATION-CONCEPTUAL DELIMITATIONS

    Directory of Open Access Journals (Sweden)

    CRISTINA FLORINA POPESCU (PANAIT

    2013-05-01

    Full Text Available Illegal migration is a mobile phenomenon, which ignores national borders, a threat that originates outside the community and extends to Western societies. This phenomenon is becoming larger and irregular migrants are often in a precarious situation and exposed to the criminals involved in various manifestations of organized crime. The future risk factors of the illegal migration are the demographic bomb, because the population is decreasing in European countries and increasing rapidly in poorer countries, droughts, floods, deforestation, that cause conflicts between climate refugees , extreme poverty, totalitarian regimes, epidemics, can trigger millions of people, the elderly and the working population imbalance which leads to the permanent import of immigrants To combat this phenomenon, states must engage and cooperate with each other. Measures taken by states must balance their integration policy for immigrants, legally residents and asylum policy to comply with international conventions. Also, states must adopt anti-immigrant policies, consisting of subordination visa policy to the interests of international security and exchange of information and, not least, to continue the Schengen process, as a value of humanitarian law applied in the field. The aim of the research is to characterize this dangerous phenomenon for the society and the goal is to identify strategies to combat illegal migration.

  9. Reservoir stratification affects methylmercury levels in river water, plankton, and fish downstream from Balbina hydroelectric dam, Amazonas, Brazil.

    Science.gov (United States)

    Kasper, Daniele; Forsberg, Bruce R; Amaral, João H F; Leitão, Rafael P; Py-Daniel, Sarah S; Bastos, Wanderley R; Malm, Olaf

    2014-01-21

    The river downstream from a dam can be more contaminated by mercury than the reservoir itself. However, it is not clear how far the contamination occurs downstream. We investigated the seasonal variation of methylmercury levels in the Balbina reservoir and how they correlated with the levels encountered downstream from the dam. Water, plankton, and fishes were collected upstream and at sites between 0.5 and 250 km downstream from the dam during four expeditions in 2011 and 2012. Variations in thermal stratification of the reservoir influenced the methylmercury levels in the reservoir and in the river downstream. Uniform depth distributions of methylmercury and oxygen encountered in the poorly stratified reservoir during the rainy season collections coincided with uniformly low methylmercury levels along the river downstream from the dam. During dry season collections, the reservoir was strongly stratified, and anoxic hypolimnion water with high methylmercury levels was exported downstream. Methylmercury levels declined gradually to 200 km downstream. In general, the methylmercury levels in plankton and fishes downstream from the dam were higher than those upstream. Higher methylmercury levels observed 200-250 km downstream from the dam during flooding season campaigns may reflect the greater inflow from tributaries and flooding of natural wetlands that occurred at this time.

  10. Water and contaminant movement: migration barriers

    International Nuclear Information System (INIS)

    Lane, L.J.; Nyhan, J.W.

    1984-11-01

    Migration barriers are used in shallow land burial facilities to slow or stop the movement of water and contaminants and are discussed here as a single component embedded in a complex environmental system. Analytical solutions to solute transport equations are used to approximate the behavior of migration barriers and to derive design criteria for control of subsurface water and contaminant migration. Various types of migration barriers are compared and design recommendations are made for shallow land burial trench caps and liners. Needed improvements and suggested field experiments for future designs of migration barriers are then discussed relative to the management of low-level radioactive wastes

  11. National and international graduate migration flows.

    Science.gov (United States)

    Mosca, Irene; Wright, Robert E

    2010-01-01

    This article examines the nature of national and international graduate migration flows in the UK. Migration equations are estimated with microdata from a matched dataset of Students and Destinations of Leavers from Higher Education, information collected by the Higher Education Statistical Agency. The probability of migrating is related to a set of observable characteristics using multinomial logit regression. The analysis suggests that migration is a selective process with graduates with certain characteristics having considerably higher probabilities of migrating, both to other regions of the UK and abroad.

  12. Family migration and relative earnings potentials

    DEFF Research Database (Denmark)

    Foged, Mette

    2016-01-01

    of husband centered migration. Couples are more likely to migrate if household earnings potential is disproportionally due to one partner, and families react equally strongly to a male and a female relative advantage in educational earnings potential. These results are driven by households with a strong......A unitarian model of family migration in which families may discount wives’ private gains is used to derive testable predictions regarding the type of couples that select into migrating. The empirical tests show that gender neutral family migration cannot be rejected against the alternative...

  13. Why Migrate: For Study or for Work?

    Directory of Open Access Journals (Sweden)

    Elise S. Brezis

    2016-08-01

    Full Text Available Over the past decades, globalization has led to a huge increase in the migration of workers, as well as students. This paper develops a simple two-step model that describes the decisions of an individual vis-à-vis education and migration, and presents a unified model, wherein the two migration decisions are combined into a single, unique model. This paper shows that under the plausible assumption that costs of migration differ over the human life cycle, the usual brain drain strategy is sub-optimal. With an increase in globalization, the brain drain strategy will be replaced by the strategy of migration of students.

  14. Monitoring of downstream salmon and steelhead at federal hydroelectric facilities, 1991

    International Nuclear Information System (INIS)

    Hawkes, L.A.; Martinson, R.D.; Smith, W.W.

    1992-04-01

    The 1991 smolt monitoring project of the National Marine Fisheries Service provided data on the seaward migration of juvenile salmon and steelhead at John Day, The Dalles and Bonneville Dams. All pertinent fish capture and condition data as well as dam operations and river flow data were provided to Fish Passage Center for use in developing fish passage indices and migration timing, and for water budget and spill management

  15. Migration of strontium-90 from a strontium-90 fluoride deep ocean source

    International Nuclear Information System (INIS)

    Yabusaki, S.

    1981-06-01

    A hypothetical rupture of a heat source capsule on the ocean floor is analyzed for strontium-90 migration and attenuation. The evolution of the three-dimensional contaminant plume is simulated by a modified version of the Okubo-Pritchard radially symmetrical, diffusion velocity dispersion model. Results from this study indicate that released solutes are confined vertically to a layer near the level of introduction. Along the plume centerline, however, water quality is affected for considerably distances downstream from the source, with the maximum effect occurring after one year

  16. MFAP4 Promotes Vascular Smooth Muscle Migration, Proliferation and Accelerates Neointima Formation

    DEFF Research Database (Denmark)

    Schlosser, Anders; Pilecki, Bartosz; Hemstra, Line E.

    2016-01-01

    in the vascular wall. The role of MFAP4 in vascular biology is unknown. We aimed to test the hypothesis that MFAP4 would enhance integrin-dependent VSMC activation. APPROACH AND RESULTS: We produced Mfap4-deficient (Mfap4(-/-)) mice and performed carotid artery ligation to explore the role of MFAP4 in vascular...... kinase and downstream kinases. In addition, we showed that MFAP4 promotes monocyte chemotaxis in integrin αVβ3-dependent manner. CONCLUSIONS: MFAP4 regulates integrin αVβ3-induced VSMC proliferation and migration, as well as monocyte chemotaxis, and accelerates neointimal hyperplasia after vascular...

  17. Men's and women's migration in coastal Ghana: An event history analysis

    Directory of Open Access Journals (Sweden)

    Holly E. Reed

    2010-04-01

    Full Text Available This article uses life history calendar (LHC data from coastal Ghana and event history statistical methods to examine inter-regional migration for men and women, focusing on four specific migration types: rural-urban, rural-rural, urban-urban, and urban-rural. Our analysis is unique because it examines how key determinants of migration-including education, employment, marital status, and childbearing-differ by sex for these four types of migration. We find that women are significantly less mobile than men overall, but that more educated women are more likely to move (particularly to urban areas than their male counterparts. Moreover, employment in the prior year is less of a deterrent to migration among women. While childbearing has a negative effect on migration, this impact is surprisingly stronger for men than for women, perhaps because women's search for assistance in childcare promotes migration. Meanwhile, being married or in union appears to have little effect on migration probabilities for either men or women. These results demonstrate the benefits of a LHC approach and suggest that migration research should further examine men's and women's mobility as it relates to both human capital and household and family dynamics, particularly in developing settings.

  18. An economic analysis of migration in Mexico.

    Science.gov (United States)

    Greenwood, M J; Ladman, J R

    1978-07-01

    This paper analyzes internal migration in Mexico over the 1960-70 period. A model of the determinants of migration is specified and estimated for aggregated interstate migration flows. Results show that distance serves as a significant deterrent to migration, that higher destination earning levels are attractive to migrants, and that regions with high unemployment rates experience lower rates of inmigration. An unanticipated finding is that regions with higher earning levels have greater rates of outmigration. The data are disaggregated to examine separate migration relationships for each state. The results are that distance is a lesser deterrent for those migrants with more accessible alternatives, that higher earning levels reduce the deterring effects of distance, and that regions with higher earning levels have lower associated elasticities of migration. It is concluded that economic factors have played a crucial role in internal migration and thus in the changing occupational and geographic structure of the Mexican labor force.

  19. The Effect of dcEFs on migration behavior of A549 cells and Integrin beta1 expression

    Directory of Open Access Journals (Sweden)

    Yunjie WANG

    2008-04-01

    Full Text Available Background and objective The effect of direct-current electric fields (dcEFs on cells attracted extensive attention. Moreover the metastasis and its potential are considered to be related to dcEFs. The aim is to study the effect of dcEFs on migration behavior of A549 cells, Integrin ?1 and its signal pathways. Methods According to exposure to 5 V/cm dcEFs or not and the time of exposure, the A549 cells were divided into 4 groups. Images were taken per 5 min within 2 h to recode the migration of the cells. The data of results were analyzed statistically. Results Most of A549cells exposed to the dcEFs aligned and elongated perpendicularly to the electric field lines and migrated to the cathode continually during 2 h. On the contrary, cells unexposed to dcEFs showed slightly random movements. Immunofluorescence showed that Integrin ?1 on plasma membrane polarized to the cathode of the dcEFs. Western blot showed that Integrin beta1 downstream signal pathways p-FAK and p-ERK were overexpressed in the dcEFs. Conclusion A549 cells have a galvanotatic feature of cathodal directed migration while exposed to the dcEFs. The polarization of Integrin beta1 and the promotion of its downstream signal pathways may play an important roles in the galvanotaxis of A549 cells.

  20. Contrasting morphodynamics in alluvial fans and fan deltas: effect of the downstream boundary

    NARCIS (Netherlands)

    Dijk, M. van; Kleinhans, M.G.; Postma, G.; Kraal, E.

    2012-01-01

    Alluvial fans and fan deltas can, in principle, have exactly the same upstream conditions, but fan deltas by definition have ponding water at their downstream boundary. This ponding creates effects on the autogenic behaviour of fan deltas, such as backwater adaptation, mouth bars and backward

  1. Influence of peak flow changes on the macroinvertebrate drift downstream of a Brazilian hydroelectric dam.

    Science.gov (United States)

    Castro, D M P; Hughes, R M; Callisto, M

    2013-11-01

    Successive daily peak flows from hydropower plants can disrupt aquatic ecosystems and alter the composition and structure of macroinvertebrates downstream. We evaluated the influence of peak flow changes on macroinvertebrate drift downstream of a hydroelectric plant as a basis for determining ecological flows that might reduce the disturbance of aquatic biota. The aim of this study was to assess the influence of flow fluctuations on the seasonal and daily drift patterns of macroinvertebrates. We collected macroinvertebrates during fixed flow rates (323 m3.s-1 in the wet season and 111 m3.s-1 in the dry season) and when peak flows fluctuated (378 to 481 m3.s-1 in the wet season, and 109 to 173 m3.s-1 in the dry season) in 2010. We collected 31,924 organisms belonging to 46 taxa in the four sampling periods. Taxonomic composition and densities of drifting invertebrates differed between fixed and fluctuating flows, in both wet and dry seasons, but family richness varied insignificantly. We conclude that macroinvertebrate assemblages downstream of dams are influenced by daily peak flow fluctuations. When making environmental flow decisions for dams, it would be wise to consider drifting macroinvertebrates because they reflect ecological changes in downstream biological assemblages.

  2. Feeding by whiteflies suppresses downstream jasmonic acid signaling by eliciting salicylic acid signaling.

    Science.gov (United States)

    Zhang, Peng-Jun; Li, Wei-Di; Huang, Fang; Zhang, Jin-Ming; Xu, Fang-Cheng; Lu, Yao-Bin

    2013-05-01

    Phloem-feeding whiteflies in the species complex Bemisia tabaci cause extensive crop damage worldwide. One of the reasons for their "success" is their ability to suppress the effectual jasmonic acid (JA) defenses of the host plant. However, little is understood about the mechanisms underlying whitefly suppression of JA-regulated defenses. Here, we showed that the expression of salicylic acid (SA)-responsive genes (EDS1 and PR1) in Arabidopsis thaliana was significantly enhanced during feeding by whitefly nymphs. Whereas upstream JA-responsive genes (LOX2 and OPR3) also were induced, the downstream JA-responsive gene (VSP1) was repressed, i.e., whiteflies only suppressed downstream JA signaling. Gene-expression analyses with various Arabidopsis mutants, including NahG, npr-1, ein2-1, and dde2-2, revealed that SA signaling plays a key role in the suppression of downstream JA defenses by whitefly feeding. Assays confirmed that SA activation enhanced whitefly performance by suppressing downstream JA defenses.

  3. Physicochemical Characteristics of River Water Downstream of a Large Tropical Hydroelectric Dam

    Directory of Open Access Journals (Sweden)

    Teck-Yee Ling

    2016-01-01

    Full Text Available Water quality in the downstream river of a hydroelectric dam may be affected by the structural design and operation. To date, little is known about the water quality downstream of the largest dam in Malaysia, the Bakun hydroelectric dam. Therefore, the objective of the study was to determine the water quality downstream of the dam when the spillway was closed and when it was opened. Results of the study indicate that the dam plays a significant role in regulating the water quality downstream of it. When the spillway was closed, pH and oxygen were lower in the river where DO was below 5 mg/L. When the spillway was opened, the water quality improved in terms of oxygen content (>8.0 mg/L, total sulphide (TS, and chemical oxygen demand (COD but deteriorated in terms of five-day biochemical oxygen demand (BOD5, total ammonia nitrogen (TAN, and total phosphorus (TP. Additionally, the intensity of the impacts, particularly BOD5, COD, and TAN, shows a declining trend as distance from the dam increases. This study shows that impacts on the water quality extend to a distance of 32 km from the dam particularly turbidity and DO and opening the spillway changes the water quality significantly.

  4. Water stress in global transboundary river basins : Significance of upstream water use on downstream stress

    NARCIS (Netherlands)

    Munia, H.; Guillaume, J. H A; Mirumachi, N.; Porkka, M.; Wada, Y.|info:eu-repo/dai/nl/341387819; Kummu, M.

    2016-01-01

    Growing population and water demand have increased pressure on water resources in various parts of the globe, including many transboundary river basins. While the impacts of upstream water use on downstream water availability have been analysed in many of these international river basins, this has

  5. Using forest carbon credits to offset emissions in the downstream business

    NARCIS (Netherlands)

    Hein, Lars

    2017-01-01

    A forthcoming report by Concawe, entitled Using Forest Carbon Credits to Offset Emissions in the Downstream Business, investigated whether, and how, forest carbon credits can be used to offset emissions from the European refining and road transport sectors. Forest carbon plays a major role in the

  6. Investigation on the intense fringe formation phenomenon downstream hot-image plane.

    Science.gov (United States)

    Hu, Yonghua; Li, Guohui; Zhang, Lifu; Huang, Wenti; Chen, Shuming

    2015-11-30

    The propagation of a high-power flat-topped Gaussian beam, which is modulated by three parallel wirelike scatterers, passing through a downstream Kerr medium slab and free spaces is investigated. A new phenomenon is found that a kind of intense fringe with intensity several times that of the incident beam can be formed in a plane downstream the Kerr medium. This kind of intense fringe is another result in the propagation process of nonlinear imaging and it locates scores of centimeters downstream the predicted hot image plane. Moreover, the intensity of this fringe can achieve the magnitude of that of hot image in corresponding single-scatterer case, and this phenomenon can arise only under certain conditions. As for the corresponding hot images, they are also formed but largely suppressed. The cause of the formation of such an intense fringe is analyzed and found related to interference in the free space downstream the Kerr medium. Moreover, the ways it is influenced by some important factors such as the wavelength of incident beam and the properties of scatterers and Kerr medium are discussed, and some important properties and relations are revealed.

  7. Linking Three Gorges Dam and downstream hydrological regimes along the Yangtze River, China

    NARCIS (Netherlands)

    Mei, X.; Dai, Z.; Van Gelder, P.H.A.J.M.; Gao, J.

    2015-01-01

    The magnitude of anthropogenic influence, especially dam regulation, on hydrological system is of scientific and practical value for large river management. As the largest dam in the world by far, Three Gorges Dam (TGD) is expected to be a strong evidence on dam impacts on downstream hydrological

  8. Regulation of notochord-specific expression of Ci-Bra downstream genes in Ciona intestinalis embryos.

    Science.gov (United States)

    Takahashi, Hiroki; Hotta, Kohji; Takagi, Chiyo; Ueno, Naoto; Satoh, Nori; Shoguchi, Eiichi

    2010-02-01

    Brachyury, a T-box transcription factor, is expressed in ascidian embryos exclusively in primordial notochord cells and plays a pivotal role in differentiation of notochord cells. Previously, we identified approximately 450 genes downstream of Ciona intestinalis Brachyury (Ci-Bra), and characterized the expression profiles of 45 of these in differentiating notochord cells. In this study, we looked for cisregulatory sequences in minimal enhancers of 20 Ci-Bra downstream genes by electroporating region within approximately 3 kb upstream of each gene fused with lacZ. Eight of the 20 reporters were expressed in notochord cells. The minimal enchancer for each of these eight genes was narrowed to a region approximately 0.5-1.0-kb long. We also explored the genome-wide and coordinate regulation of 43 Ci-Bra-downstream genes. When we determined their chromosomal localization, it became evident that they are not clustered in a given region of the genome, but rather distributed evenly over 13 of the 14 pairs of chromosomes, suggesting that gene clustering does not contribute to coordinate control of the Ci-Bra downstream gene expression. Our results might provide Insights Into the molecular mechanisms underlying notochord formation in chordates.

  9. Modelling the role of transmission companies in the downstream European gas market

    International Nuclear Information System (INIS)

    Boots, M.A.; Rijkers, F.A.M.

    2000-07-01

    This paper describes the empirical model GASTALE and shows several analyses of the European gas market using this model. These analyses are mainly focused on the role of the downstream transmission companies. Producers of natural gas are assumed to form an oligopoly throughout the paper. Considering an oligopolistic transmission structure our model results show that the level of transmitters' profits strongly depends on the possibilities of discrimination on the border prices. If price discrimination by producers is allowed, these producers collect the main part of the margins on end-use prices. Without price discrimination the transmission companies collect most of the margins. Assuming an oligopolistic downstream structure, end-use prices converge to prices corresponding to perfect competition when the number of transmitters increases. Given the oligopolistic structure of the upstream industry, it is of importance to prevent (or abolish) monopolistic structures in the downstream gas market. In the case where oligopolistic competition between downstream gas companies cannot be prevented, vertical integration should be supported (or at least not be discouraged). 14 refs

  10. 40 CFR 80.219 - Designation and downstream requirements for GPA gasoline.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Designation and downstream requirements for GPA gasoline. 80.219 Section 80.219 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... sold or dispensed for use in motor vehicles at a retail outlet or wholesale purchaser-consumer facility...

  11. Concentration of radionuclides in fresh water fish downstream of Rancho Seco Nuclear Generating Plant

    International Nuclear Information System (INIS)

    Noshkin, V.E.; Eagle, R.J.; Dawson, J.M.; Brunk, J.L.; Wong, X.M.

    1984-01-01

    Fish were collected for radionuclide analysis over a 5-month period in 1984 from creeks downstream of the Rancho Seco Nuclear Generating Plant, which has been discharging quantities of some fission and activation products to the waterway since 1981. Among the fish, the bluegill was selected for intensive study because it is very territorial and the radionuclide concentrations detected should be representative of the levels in the local environment at the downstream locations sampled. Among the gamma-emitting radionuclides routinely released, only 134 Cs and 137 Cs were detected in the edible flesh of fish. Concentrations in the flesh of fish decreased with distance from the plant. The relationship between concentration and distance was determined to be exponential. Exponential equations were generated to estimate concentrations in fish at downstream locations where no site-specific information was available. Mean concentrations of 137 Cs in bluegill collected during April, May, July and August from specific downstream stations were not significantly different in spite of the release of 131 mCi to the creeks between April and August. The concentrations in fish are not responding to changes in water concentrations brought about by plant discharges. Diet appears to be a more significant factor than size or weight or water concentration in regulating body burdens of 137 Cs in these fish

  12. Trauma, post-migration living difficulties, and social support as predictors of psychological adjustment in resettled Sudanese refugees.

    Science.gov (United States)

    Schweitzer, Robert; Melville, Fritha; Steel, Zachary; Lacherez, Philippe

    2006-02-01

    This paper explores the impact of pre-migration trauma, post-migration living difficulties and social support on the current mental health of 63 resettled Sudanese refugees. A semistructured interview including questionnaires assessing sociodemographic information, pre-migration trauma, anxiety, depression and posttraumatic stress, post-migration living difficulties and perceived social support were administered assisted by a bilingual community worker. Resettled refugees from Sudan evidenced a history of trauma. Less than 5% met criteria for posttraumatic stress but 25% reported clinically high levels of psychological distress. The results indicate that social support--particularly perceived social support from the migrant's ethnic community--play a significant role in predicting mental health outcomes. Pre-migration trauma, family status and gender were also associated with mental health outcomes. Refugees in Australia may constitute a particularly vulnerable group in terms of mental health outcomes. Culturally specific sequelae in terms of social isolation and acculturation may be particularly problematic for these migrants.

  13. Reduced rearing density increases postrelease migration success of Atlantic salmon (Salmo salar) smolts

    DEFF Research Database (Denmark)

    Larsen, Martin Hage; Johnsson, Jörgen I; Näslund, Joacim

    2016-01-01

    during rearing in the hatchery. However, individuals reared at reduced density had less eroded dorsal fins and opercula relative to those from the high-density treatment. In the stream, the downstream migration success was 16% higher for fish reared at reduced density than for conspecifics kept at high-density......The overall aim of this study was to investigate the effect of rearing density on the post-release survival of Atlantic salmon (Salmo salar) smolts during seaward migration. Fish were either reared at conventional hatchery density or at one-third of conventional density. Three hundred one-year old...... smolts from each density treatment were individually tagged with passive integrated transponder (PIT) tags and released 3.2 km upstream of a stationary antenna array in a natural stream. There were no significant differences in length, body mass, or condition between fish from the two density treatments...

  14. Modelling the effect of diffusion into the rock matrix on radionuclide migration

    International Nuclear Information System (INIS)

    Lever, D.A.; Bradbury, M.H.; Hemingway, S.J.

    1983-01-01

    Diffusion into the rock matrix is potentially an important retardation mechanism for nuclides leached from an underground radioactive waste repository in a fractured hard rock. Models of this diffusion process are discussed and incorporated into three-dimensional radionuclide migration models. Simple solutions to these models are derived for two regions: the region near to the repository where the nuclide is diffusing into effectively infinite rock, and that much further downstream where the concentrations in the rock and fractures are almost in equilibrium. These solutions are used to evaluate the possible impact on migration. It is shown that retardation factors in excess of 100 and reductions in the peak concentration at a given point on the flow path by three or four orders of magnitude are possibe for non-sorbed ions, which would otherwise be carried by the flow and not retarded at all. (author)

  15. Hox paralog group 2 genes control the migration of mouse pontine neurons through slit-robo signaling.

    Directory of Open Access Journals (Sweden)

    Marc J Geisen

    2008-06-01

    Full Text Available The pontine neurons (PN represent a major source of mossy fiber projections to the cerebellum. During mouse hindbrain development, PN migrate tangentially and sequentially along both the anteroposterior (AP and dorsoventral (DV axes. Unlike DV migration, which is controlled by the Netrin-1/Dcc attractive pathway, little is known about the molecular mechanisms guiding PN migration along the AP axis. Here, we show that Hoxa2 and Hoxb2 are required both intrinsically and extrinsically to maintain normal AP migration of subsets of PN, by preventing their premature ventral attraction towards the midline. Moreover, the migration defects observed in Hoxa2 and Hoxb2 mutant mice were phenocopied in compound Robo1;Robo2, Slit1;Slit2, and Robo2;Slit2 knockout animals, indicating that these guidance molecules act downstream of Hox genes to control PN migration. Indeed, using chromatin immunoprecipitation assays, we further demonstrated that Robo2 is a direct target of Hoxa2 in vivo and that maintenance of high Robo and Slit expression levels was impaired in Hoxa2 mutant mice. Lastly, the analysis of Phox2b-deficient mice indicated that the facial motor nucleus is a major Slit signaling source required to prevent premature ventral migration of PN. These findings provide novel insights into the molecular control of neuronal migration from transcription factor to regulation of guidance receptor and ligand expression. Specifically, they address the question of how exposure to multiple guidance cues along the AP and DV axes is regulated at the transcriptional level and in turn translated into stereotyped migratory responses during tangential migration of neurons in the developing mammalian brain.

  16. Favorable fragmentation: river reservoirs can impede downstream expansion of riparian weeds.

    Science.gov (United States)

    Rood, Stewart B; Braatne, Jeffrey H; Goater, Lori A

    2010-09-01

    River valleys represent biologically rich corridors characterized by natural disturbances that create moist and barren sites suitable for colonization by native riparian plants, and also by weeds. Dams and reservoirs interrupt the longitudinal corridors and we hypothesized that this could restrict downstream weed expansion. To consider this "reservoir impediment" hypothesis we assessed the occurrences and abundances of weeds along a 315-km river valley corridor that commenced with an unimpounded reach of the Snake River and extended through Brownlee, Oxbow, and Hells Canyon reservoirs and dams, and downstream along the Snake River. Sampling along 206 belt transects with 3610 quadrats revealed 16 noxious and four invasive weed species. Ten weeds were upland plants, with Canada thistle (Cirsium arvense) restricted to the upstream reaches, where field morning glory (Convolvulus arvensis) was also more common. In contrast, St. John's wort (Hypericum perforatum) was more abundant below the dams, and medusahead wildrye (Taeniatherum caput-medusae) occurred primarily along the reservoirs. All seven riparian species were abundant in the upstream zones but sparse or absent below the dams. This pattern was observed for the facultative riparian species, poison hemlock (Conium maculatum) and perennial pepperweed (Lepidium latifolium), the obligate riparian, yellow nut sedge (Cyperus esculentus), the invasive perennial, reed canary grass (Phalaris arundinacea), and three invasive riparian trees, Russian olive (Elaeagnus angustifolia), false indigo (Amorpha fruticosa), and tamarisk (Tamarix spp.). The hydrophyte purple loosestrife (Lythrum salicaria) was also restricted to the upstream zone. These longitudinal patterns indicate that the reservoirs have impeded the downstream expansion of riparian weeds, and this may especially result from the repetitive draw-down and refilling of Brownlee Reservoir that imposes a lethal combination of drought and flood stress. The dams and

  17. C, N, P export regimes from headwater catchments to downstream reaches

    Science.gov (United States)

    Dupas, R.; Musolff, A.; Jawitz, J. W.; Rao, P. S.; Jaeger, C. G.; Fleckenstein, J. H.; Rode, M.; Borchardt, D.

    2017-12-01

    Excessive amounts of nutrients and dissolved organic matter in freshwater bodies affect aquatic ecosystems. In this study, the spatial and temporal variability in nitrate (NO3), dissolved organic carbon (DOC) and soluble reactive phosphorus (SRP) was analyzed in the Selke river continuum from headwaters draining 1 - 3 km² catchments to downstream reaches representing spatially integrated signals from 184 - 456 km² catchments (part of TERENO - Terrestrial Environmental Observatories, in Germany). Three headwater catchments were selected as archetypes of the main landscape units (land use x lithology) present in the Selke catchment. Export regimes in headwater catchments were interpreted in terms of NO3, DOC and SRP land-to-stream transfer processes. Headwater signals were subtracted from downstream signals, with the differences interpreted in terms of in-stream processes and contribution of point-source emissions. The seasonal dynamics for NO3 were opposite those of DOC and SRP in all three headwater catchments, and spatial differences also showed NO3 contrasting with DOC and SRP. These dynamics were interpreted as the result of the interplay of hydrological and biogeochemical processes, for which riparian zones were hypothesized to play a determining role. In the two downstream reaches, NO3 was transported almost conservatively, whereas DOC was consumed and produced in the upper and lower river sections, respectively. The natural export regime of SRP in the three headwater catchments mimicked a point-source signal, which may lead to overestimation of domestic contributions in the downstream reaches. Monitoring the river continuum from headwaters to downstream reaches proved effective to investigate jointly land-to-stream and in-stream transport and transformation processes.

  18. Willingness of upstream and downstream resource managers to engage in compensation schemes for environmental services

    Directory of Open Access Journals (Sweden)

    Chapika Sangkapitux

    2009-04-01

    Full Text Available Providing compensation for agricultural conservation practices adopted by upstream farmers is still an alien concept in the Thai political context. The governance of common-pool natural resources, such as forest and water, has traditionally been under the control of powerful government line agencies, while the contribution of local communities to natural resource conservation have been hardly recognized by policy-makers. Drawing on a case study in Mae Sa watershed, Chiang Mai province, northern Thailand, this paper discusses the potential of developing compensation schemes in a socio-political context where upland farmers – mostly belonging to ethnic minority groups – tend to be considered a threat to the natural resource base rather than providers of environmental services. Based on data obtained from 371 households in the upstream communities and 151 households in the downstream communities of the watershed, upstream resource managers’ willingness to accept compensation for the conservation measures and downstream resource managers’ willingness to pay for water resource improvements were estimated through the use of choice experiments. Results from the study suggest that downstream resource managers would be willing to provide on average nearly 1% of their annual income for a substantial improvement of the quantity and quality of water resources, which could be achieved by compensating upstream farmers’ change of their agricultural systems towards more environment-friendly practices. Both willingness to pay of downstream respondents and willingness of upstream resource managers to accept compensation were positively correlated with age, education, participation in environmental conservation activities and previous experiences with droughts and/or erosion. The paper concludes that there is a clear potential for establishing compensation schemes for provision of environmental services in northern Thai watersheds. The important policy

  19. Water Stress in Global Transboundary River Basins: Significance of Upstream Water Use on Downstream Stress

    Science.gov (United States)

    Munia, H.; Guillaume, J. H. A.; Mirumachi, N.; Porkka,M.; Wada, Yoshihide; Kummu, M.

    2016-01-01

    Growing population and water demand have increased pressure on water resources in various parts of the globe, including many transboundary river basins. While the impacts of upstream water use on downstream water availability have been analyzed in many of these international river basins, this has not been systematically done at the global scale using coherent and comparable datasets. In this study, we aim to assess the change in downstream water stress due to upstream water use in the world's transboundary river basins. Water stress was first calculated considering only local water use of each sub-basin based on country-basin mesh, then compared with the situation when upstream water use was subtracted from downstream water availability. Wefound that water stress was generally already high when considering only local water use, affecting 0.95-1.44 billion people or 33%-51% of the population in transboundary river basins. After accounting for upstream water use, stress level increased by at least 1 percentage-point for 30-65 sub-basins, affecting 0.29-1.13 billion people. Altogether 288 out of 298 middle-stream and downstream sub-basin areas experienced some change in stress level. Further, we assessed whether there is a link between increased water stress due to upstream water use and the number of conflictive and cooperative events in the transboundary river basins, as captured by two prominent databases. No direct relationship was found. This supports the argument that conflicts and cooperation events originate from a combination of different drivers, among which upstream-induced water stress may play a role. Our findings contribute to better understanding of upstream-downstream dynamics in water stress to help address water allocation problems.

  20. Energy-saving scheme based on downstream packet scheduling in ethernet passive optical networks

    Science.gov (United States)

    Zhang, Lincong; Liu, Yejun; Guo, Lei; Gong, Xiaoxue

    2013-03-01

    With increasing network sizes, the energy consumption of Passive Optical Networks (PONs) has grown significantly. Therefore, it is important to design effective energy-saving schemes in PONs. Generally, energy-saving schemes have focused on sleeping the low-loaded Optical Network Units (ONUs), which tends to bring large packet delays. Further, the traditional ONU sleep modes are not capable of sleeping the transmitter and receiver independently, though they are not required to transmit or receive packets. Clearly, this approach contributes to wasted energy. Thus, in this paper, we propose an Energy-Saving scheme that is based on downstream Packet Scheduling (ESPS) in Ethernet PON (EPON). First, we design both an algorithm and a rule for downstream packet scheduling at the inter- and intra-ONU levels, respectively, to reduce the downstream packet delay. After that, we propose a hybrid sleep mode that contains not only ONU deep sleep mode but also independent sleep modes for the transmitter and the receiver. This ensures that the energy consumed by the ONUs is minimal. To realize the hybrid sleep mode, a modified GATE control message is designed that involves 10 time points for sleep processes. In ESPS, the 10 time points are calculated according to the allocated bandwidths in both the upstream and the downstream. The simulation results show that ESPS outperforms traditional Upstream Centric Scheduling (UCS) scheme in terms of energy consumption and the average delay for both real-time and non-real-time packets downstream. The simulation results also show that the average energy consumption of each ONU in larger-sized networks is less than that in smaller-sized networks; hence, our ESPS is better suited for larger-sized networks.

  1. The role of grazers and shredders in the retention and downstream transport of a PCB in lotic environments

    International Nuclear Information System (INIS)

    Sallenave, R.M.; Kreutzweiser, D.P.

    1994-01-01

    Field studies using flow-through artificial stream channels were conducted between May and October 1992 to study the role of the feeding activity of grazing and shredding invertebrates in promoting downstream transport of 2,2',4,4',5,5'-hexachlorobiphenyl (HCBP). Plant material was labeled with [ 14 C]HCBP and fed to selected invertebrate species, and accrual of radioactivity by downstream collector species (Hydropsyche spp.) was measured. Downstream transport of HCBP was significantly increased by the presence of the grazer Elimia livescens in the upstream sections of the channels as demonstrated by significantly higher levels of radioactivity in hydropsychid larvae located downstream. Similarly, movement of HCBP downstream was significantly greater in channels containing the shredder Hydatophylax argus than in channels without shredders. These results suggest that the feeding processes of benthic invertebrates may play an important role in the downstream transport of particle-bound hydrophobic organic compounds

  2. Radiological and migration results of the DURALOC(R)-cup after two years

    International Nuclear Information System (INIS)

    Juen, F.

    2000-10-01

    In 1997 a study was conduced concerning 69 consecutive patients, all of whom consisted of DURALOC(R) series 100 acetabular components. The clinical, radiological and migrational aspect of each component was investigated 2 and 4 years postoperatively. In addition to this, a further 92 cups were analyzed in an identical manner, again 2 years after implantation. This therefore equated to a total of 161 investigated cups after a follow up interval of 2 years. In 144 of these cases the cup was combined with a cementless hydroxyapatite coated Spotorno shaft, with the remaining 17 involving a cemented Link-shaft (Lubinus SP II). A 28 mm Biolox(R) ceramic head was constant in all cases. Clinical data for each cup was collected via completion of a standard examination form, while acetabular migration, both vertical and horizontal, was measured on serial radiographs by the computer assisted EBRA method. From analyses of collected data, it was clearly shown that the clinical results remained very good over the 2- and 4-year-periods however, from radiological evidence it was indicated that for the period 3-4 years postoperatively, an increasing amount of radiolucencies around the cups were apparent. There was clearly no correlation between clinical and migration results. From the data taken from 106 migration curves, the mean total migration over the initial two-year-period was calculated to be 0.88 mm. From analysis of a further 56 migration curves, the mean total migration within 4 years of implantation was assessed to be 1.23 mm, however a decreasing speed of migration over the final 2-year-period was indicated. Our results demonstrate that statements relating to migration results of particular cups are more accurate after four years. However, statements about mean migration values are possible after two years. A migration speed of 1 mm total migration within the first 2 years after operation was predictive for radiological loosening of the cup after four years (p=0

  3. Return migration as failure or success? : The determinants of return migration intentions among Moroccan migrants in Europe

    NARCIS (Netherlands)

    de Haas, H.; Fokkema, T.; Fihri, M.F.

    2015-01-01

    Different migration theories generate competing hypotheses with regard to determinants of return migration. While neoclassical migration theory associates migration to the failure to integrate at the destination, the new economics of labour migration sees return migration as the logical stage after

  4. Philippine migration policy: dilemmas of a crisis.

    Science.gov (United States)

    Battistella, G

    1999-04-01

    Philippine migration policy is traced from the early 1970s to the present. The main migration trends in the 1990s are described. An assessment is made of the efficacy and appropriateness of present migration policy in light of the economic crisis. A regional approach to migration policy is necessary in order to encourage placing migration as a greater priority on national agendas and in bilateral agreements. In the Philippines, migrants are considered better paid workers, which diminishes their importance as a legislative or program priority. Santo Tomas (1998) conducted an empirical assessment of migration policies in the Philippines, but refinement is needed. Although migration is a transnational experience, there is little dialogue and cooperation among countries. Philippine migration policy defines its role as an information resource for migrants. Policy shifted from labor export to migrant management in the public and private sectors. Predeparture information program studies are recommending a multi-stage process that would involve all appropriate parties. There is talk of including migration information in the education curriculum. There are a variety of agendas, competing interests, and information resources between migration networks and officiating agencies. The Asian financial crisis may have a mild impact, but there are still issues of reintegration, protection, and employment conditions

  5. Asian student migration to Australia.

    Science.gov (United States)

    Shu, J; Hawthorne, L

    1996-01-01

    "This paper presents an overview of Asian student migration to Australia, together with an analysis of political and educational aspects of the overseas student programme. It focuses on some significant consequences of this flow for Australia. The characteristics of key student groups are contrasted to provide some perspective of the diversity of historical and cultural backgrounds, with the source countries of Malaysia, Indonesia and PRC [China] selected as case studies. Since the issue of PRC students in Australia has attracted considerable public attention and policy consideration, particular focus is placed on their experience." (SUMMARY IN FRE AND SPA) excerpt

  6. Clandestine labor migration to Taiwan.

    Science.gov (United States)

    Tsay, C

    1992-01-01

    "Illegal migration to Taiwan is a recent phenomenon but with a rapid rate of increase. Most illegal foreign workers enter on visitor's visas and overstay. This paper's detailed analysis of official data reveals that Malaysia, Philippines, Indonesia and Thailand are the major sources, providing a stock of mostly male workers numbering around 40,000. Sociodemographic and attitudinal changes among Taiwanese workers coupled with labor shortages in low-skilled jobs are pressuring the Taiwanese government to formulate plans for a systematic importation of foreign labor." excerpt

  7. Migrating Applications to IPv6

    CERN Document Server

    York, Dan

    2011-01-01

    If IPv6 is to be adopted on a large scale, the applications running on desktop systems, laptops, and even mobile devices need to work just as well with this protocol as they do with IPv4. This concise book takes you beyond the network layer and helps you explore the issues you need to address if you are to successfully migrate your apps to IPv6. It's ideal for application developers, system/network architects, product managers, and others involved in moving your network to IPv6. Explore changes you need to make in your application's user interfaceMake sure your application is retrieving corre

  8. Radionuclide migration in geological formations

    International Nuclear Information System (INIS)

    Barbreau, A.; Heremans, R.; Skytte Jensen, B.

    1980-01-01

    Radioactive waste disposal into geological formation is based on the capacity of rocks to confine radioactivity for a long period of time. Radionuclide migration from the repository to the environment depends on different mechanisms and phenomena whose two main ones are groundwater flow and the retention and ion-exchange property of rocks. Many studies are underway presently in EEC countries concerning hydrodynamic characteristics of deep geological formations as well as in radionuclide retention capacity and modelling. Important results have already been achieved which show the complexity of some phenomena and further studies shall principally be developed taking into account real conditions of the repository and its environment

  9. 17-Beta estradiol and 4-nonylphenol delay smolt development and downstream migration in Atlantic salmon, Salmo salar

    DEFF Research Database (Denmark)

    Madsen, Steffen S; Skovbølling, Søren; Nielsen, Christian

    2004-01-01

    by increased gill Na+, K+ -ATPase activity and 24 h sea water (SW)-tolerance. Starting late March, three groups of 150 fish were each given 6 serial injections over 20 days of 2 µg/g body weight E2, 120 µg/g 4-NP dissolved in peanut oil or peanut oil (4 µl/g) as control. After the last injection, all fish were...

  10. p53/PUMA expression in human pulmonary fibroblasts mediates cell activation and migration in silicosis.

    Science.gov (United States)

    Wang, Wei; Liu, Haijun; Dai, Xiaoniu; Fang, Shencun; Wang, Xingang; Zhang, Yingming; Yao, Honghong; Zhang, Xilong; Chao, Jie

    2015-11-18

    Phagocytosis of SiO2 into the lung causes an inflammatory cascade that results in fibroblast proliferation and migration, followed by fibrosis. Clinical evidence has indicated that the activation of alveolar macrophages by SiO2 produces rapid and sustained inflammation characterized by the generation of monocyte chemotactic protein 1, which, in turn, induces fibrosis. However, the details of events downstream of monocyte chemotactic protein 1 activity in pulmonary fibroblasts remain unclear. Here, to elucidate the role of p53 in fibrosis induced by silica, both the upstream molecular mechanisms and the functional effects on cell proliferation and migration were investigated. Experiments using primary cultured adult human pulmonary fibroblasts led to the following results: 1) SiO2 treatment resulted in a rapid and sustained increase in p53 and PUMA protein levels; 2) the MAPK and PI3K pathways were involved in the SiO2-induced alteration of p53 and PUMA expression; and 3) RNA interference targeting p53 and PUMA prevented the SiO2-induced increases in fibroblast activation and migration. Our study elucidated a link between SiO2-induced p53/PUMA expression in fibroblasts and cell migration, thereby providing novel insight into the potential use of p53/PUMA in the development of novel therapeutic strategies for silicosis treatment.

  11. Behavior and potential threats to survival of migrating lamprey ammocoetes and macrophthalmia

    Energy Technology Data Exchange (ETDEWEB)

    Moser, Mary L.; Jackson, Aaron D.; Lucas, Martyn C.; Mueller, Robert P.

    2015-03-01

    Upon metamorphosis, anadromous juvenile lamprey (macrophthalmia) exhibit distinct migration behaviors that take them from larval rearing habitats in streams to the open ocean. While poorly studied, lamprey larvae (ammocoetes) also engage in downstream movement to some degree. Like migrating salmon smolts, lamprey macrophthalmia undergo behavioral changes associated with a highly synchronized metamorphosis. Unlike salmon smolts, the timing of juvenile migration in lamprey is protracted and poorly documented. Lamprey macrophthalmia and ammocoetes are not strong swimmers, attaining maximum individual speeds of less than 1 m s-1, and sustained speeds of less than 0.5 m s-1. They are chiefly nocturnal and distribute throughout the water column, but appear to concentrate near the bottom in the thalweg of deep rivers. At dams and irrigation diversions, macrophthalmia can become impinged on screens or entrained in irrigation canals, suffer increased predation, and experience physical injury that may result in direct or delayed mortality. The very structures designed to protect migrating juvenile salmonids can be harmful to juvenile lamprey. Yet at turbine intakes and spillways, lampreys, which have no swim bladder, can withstand changes in pressure and shear stress large enough to injure or kill most teleosts. Lamprey populations are in decline in many parts of the world, with some species designated as species of concern for conservation that merit legally mandated protections. Hence, provisions for safe passage of juvenile lamprey are being considered at dams and water diversions in North America and Europe.

  12. p21-Activated kinase (PAK regulates cytoskeletal reorganization and directional migration in human neutrophils.

    Directory of Open Access Journals (Sweden)

    Asako Itakura

    Full Text Available Neutrophils serve as a first line of defense in innate immunity owing in part to their ability to rapidly migrate towards chemotactic factors derived from invading pathogens. As a migratory function, neutrophil chemotaxis is regulated by the Rho family of small GTPases. However, the mechanisms by which Rho GTPases orchestrate cytoskeletal dynamics in migrating neutrophils remain ill-defined. In this study, we characterized the role of p21-activated kinase (PAK downstream of Rho GTPases in cytoskeletal remodeling and chemotactic processes of human neutrophils. We found that PAK activation occurred upon stimulation of neutrophils with f-Met-Leu-Phe (fMLP, and PAK accumulated at the actin-rich leading edge of stimulated neutrophils, suggesting a role for PAK in Rac-dependent actin remodeling. Treatment with the pharmacological PAK inhibitor, PF3758309, abrogated the integrity of RhoA-mediated actomyosin contractility and surface adhesion. Moreover, inhibition of PAK activity impaired neutrophil morphological polarization and directional migration under a gradient of fMLP, and was associated with dysregulated Ca(2+ signaling. These results suggest that PAK serves as an important effector of Rho-family GTPases in neutrophil cytoskeletal reorganization, and plays a key role in driving efficient directional migration of human neutrophils.

  13. Regulation of Glioma Cell Migration by Seri ne-Phosphorylated P3111

    Directory of Open Access Journals (Sweden)

    Wendy S. McDonough

    2005-09-01

    Full Text Available P311, an 8-kDa polypeptide, was previously shown to be highly expressed in invasive glioma cells. Here, we report the functional characteristics of P311 with regard to influencing glioma cell migration. P311 is constitutively serine-phosphorylated; decreased phosphorylation is observed in migration-activated glioma cells. The primary amino acid sequence of P311 indicates a putative serine phosphorylation site (S59 near the PEST domain. Site-directed mutagenesis of S59A retarded P311 degradation, induced glioma cell motility. In contrast, S59D mutation resulted in the rapid degradation of P311, reduced glioma cell migration. Coimmunoprecipitation coupled with matrixassisted laser desorption/ionization time-of-flight mass spectrometry analysis identified Filamin A as a binding partner of P311, immunofluorescence studies showed that both proteins colocalized at the cell periphery. Moreover, P311-induced cell migration was abrogated by inhibition of β1 integrin function using TACβ1A, a dominant-negative inhibitor of β1 integrin signaling, suggesting that P311 acts downstream of β1 signaling. Finally, overexpression of P311 or P311 S59A mutant protein activates Raci GTPase; small interfering RNA-mediated depletion of Raci suppresses P311-induced motility. Collectively, these results suggest a role for levels of P311 in regulating glioma motility, invasion through the reorganization of actin cytoskeleton at the cell periphery.

  14. Survival of migrating salmon smolts in large rivers with and without dams.

    Directory of Open Access Journals (Sweden)

    David W Welch

    2008-10-01

    Full Text Available The mortality of salmon smolts during their migration out of freshwater and into the ocean has been difficult to measure. In the Columbia River, which has an extensive network of hydroelectric dams, the decline in abundance of adult salmon returning from the ocean since the late 1970s has been ascribed in large measure to the presence of the dams, although the completion of the hydropower system occurred at the same time as large-scale shifts in ocean climate, as measured by climate indices such as the Pacific Decadal Oscillation. We measured the survival of salmon smolts during their migration to sea using elements of the large-scale acoustic telemetry system, the Pacific Ocean Shelf Tracking (POST array. Survival measurements using acoustic tags were comparable to those obtained independently using the Passive Integrated Transponder (PIT tag system, which is operational at Columbia and Snake River dams. Because the technology underlying the POST array works in both freshwater and the ocean, it is therefore possible to extend the measurement of survival to large rivers lacking dams, such as the Fraser, and to also extend the measurement of survival to the lower Columbia River and estuary, where there are no dams. Of particular note, survival during the downstream migration of at least some endangered Columbia and Snake River Chinook and steelhead stocks appears to be as high or higher than that of the same species migrating out of the Fraser River in Canada, which lacks dams. Equally surprising, smolt survival during migration through the hydrosystem, when scaled by either the time or distance migrated, is higher than in the lower Columbia River and estuary where dams are absent. Our results raise important questions regarding the factors that are preventing the recovery of salmon stocks in the Columbia and the future health of stocks in the Fraser River.

  15. Migration of cesium-137 through sandy soil layer effect of fine silt on migration

    International Nuclear Information System (INIS)

    Ohnuki, Toshihiko; Wadachi, Yoshiki

    1983-01-01

    The migration of 137 Cs through sandy soil layer was studied with consideration of the migration of fine silt by column method. It was found that a portion of fine silt migrated through the soil layer accompanying with 137 Cs. The mathematical migration model of 137 Cs involved the migration of fine silt through such soil layer was presented. This model gave a good accordance between calculated concentration distribution curve in sandy soil layer and effluent curve and observed those. So, this model seems to be advanced one for evaluating migration of 137 Cs in sandy soil layer with silt. (author)

  16. Flow and mass transfer downstream of an orifice under flow accelerated corrosion conditions

    International Nuclear Information System (INIS)

    Ahmed, Wael H.; Bello, Mufatiu M.; El Nakla, Meamer; Al Sarkhi, Abdelsalam

    2012-01-01

    Highlights: ► Mass transfer downstream of orifices was numerically and experimentally investigated. ► The surface wear pattern is measured and used to validate the present numerical results. ► The maximum mass transfer coefficient found to occur at approximately 2–3 pipe diameters downstream of the orifice. ► The FAC wear rates were correlated with the turbulence kinetic energy and wall mass transfer in terms of Sherwood number. ► The current study offered very useful information for FAC engineers for better preparation of nuclear plant inspection scope. - Abstract: Local flow parameters play an important role in characterizing flow accelerated corrosion (FAC) downstream of sudden area change in power plant piping systems. Accurate prediction of the highest FAC wear rate locations enables the mitigation of sudden and catastrophic failures, and the improvement of the plant capacity factor. The objective of the present study is to evaluate the effect of the local flow and mass transfer parameters on flow accelerated corrosion downstream of an orifice. In the present study, orifice to pipe diameter ratios of 0.25, 0.5 and 0.74 were investigated numerically by solving the continuity and momentum equations at Reynolds number of Re = 20,000. Laboratory experiments, using test sections made of hydrocal (CaSO 4 ·½H 2 O) were carried out in order to determine the surface wear pattern and validate the present numerical results. The numerical results were compared to the plants data as well as to the present experiments. The maximum mass transfer coefficient found to occur at approximately 2–3 pipe diameters downstream of the orifice. This location was also found to correspond to the location of elevated turbulent kinetic energy generated within the flow separation vortices downstream of the orifice. The FAC wear rates were correlated with the turbulence kinetic energy and wall mass transfer in terms of Sherwood number. The current study found to offer very

  17. The effect of CD4 receptor downregulation and its downstream signaling molecules on HIV-1 latency

    International Nuclear Information System (INIS)

    Kim, Kyung-Chang; Kim, Hyeon Guk; Roh, Tae-Young; Park, Jihwan; Jung, Kyung-Min; Lee, Joo-Shil; Choi, Sang-Yun; Kim, Sung Soon; Choi, Byeong-Sun

    2011-01-01

    Research highlights: → CD4 receptors were downregulated on the surface of HIV-1 latently infected cells. → CD4 downstream signaling molecules were suppressed in HIV-1 latently infected cells. → HIV-1 progeny can be reactivated by induction of T-cell activation signal molecules. → H3K4me3 and H3K9ac were highly enriched in CD4 downstream signaling molecules. → HIV-1 latency can be maintained by the reduction of downstream signaling molecules. -- Abstract: HIV-1 can establish a latent infection in memory CD4 + T cells to evade the host immune response. CD4 molecules can act not only as the HIV-1 receptor for entry but also as the trigger in an intracellular signaling cascade for T-cell activation and proliferation via protein tyrosine kinases. Novel chronic HIV-1-infected A3.01-derived (NCHA) cells were used to examine the involvement of CD4 downstream signaling in HIV-1 latency. CD4 receptors in NCHA cells were dramatically downregulated on its surface but were slightly decreased in whole-cell lysates. The expression levels of CD4 downstream signaling molecules, including P56 Lck , ZAP-70, LAT, and c-Jun, were sharply decreased in NCHA cells. The lowered histone modifications of H3K4me3 and H3K9ac correlated with the downregulation of P56 Lck , ZAP-70, and LAT in NCHA cells. AP-1 binding activity was also reduced in NCHA cells. LAT and c-Jun suppressed in NCHA cells were highly induced after PMA treatment. In epigenetic analysis, other signal transduction molecules which are associated with active and/or latent HIV-1 infection showed normal states in HIV-1 latently infected cells compared to A3.01 cells. In conclusion, we demonstrated that the HIV-1 latent state is sustained by the reduction of downstream signaling molecules via the downregulation of CD4 and the attenuated activity of transcription factor as AP-1. The HIV-1 latency model via T-cell deactivation may provide some clues for the development of the new antireservoir therapy.

  18. The effect of CD4 receptor downregulation and its downstream signaling molecules on HIV-1 latency

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyung-Chang [National Institute of Health, Chungbuk (Korea, Republic of); School of Life Science and Biotechnology, Korea University, Seoul (Korea, Republic of); Kim, Hyeon Guk [National Institute of Health, Chungbuk (Korea, Republic of); Roh, Tae-Young [Division of Molecular and Life Science, Pohang University of Science and Technology, Pohang, Gyeongbuk (Korea, Republic of); Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang, Gyeongbuk (Korea, Republic of); Park, Jihwan [Division of Molecular and Life Science, Pohang University of Science and Technology, Pohang, Gyeongbuk (Korea, Republic of); Jung, Kyung-Min; Lee, Joo-Shil [National Institute of Health, Chungbuk (Korea, Republic of); Choi, Sang-Yun [School of Life Science and Biotechnology, Korea University, Seoul (Korea, Republic of); Kim, Sung Soon [National Institute of Health, Chungbuk (Korea, Republic of); Choi, Byeong-Sun, E-mail: byeongsun@korea.kr [National Institute of Health, Chungbuk (Korea, Republic of)

    2011-01-14

    Research highlights: {yields} CD4 receptors were downregulated on the surface of HIV-1 latently infected cells. {yields} CD4 downstream signaling molecules were suppressed in HIV-1 latently infected cells. {yields} HIV-1 progeny can be reactivated by induction of T-cell activation signal molecules. {yields} H3K4me3 and H3K9ac were highly enriched in CD4 downstream signaling molecules. {yields} HIV-1 latency can be maintained by the reduction of downstream signaling molecules. -- Abstract: HIV-1 can establish a latent infection in memory CD4 + T cells to evade the host immune response. CD4 molecules can act not only as the HIV-1 receptor for entry but also as the trigger in an intracellular signaling cascade for T-cell activation and proliferation via protein tyrosine kinases. Novel chronic HIV-1-infected A3.01-derived (NCHA) cells were used to examine the involvement of CD4 downstream signaling in HIV-1 latency. CD4 receptors in NCHA cells were dramatically downregulated on its surface but were slightly decreased in whole-cell lysates. The expression levels of CD4 downstream signaling molecules, including P56{sup Lck}, ZAP-70, LAT, and c-Jun, were sharply decreased in NCHA cells. The lowered histone modifications of H3K4me3 and H3K9ac correlated with the downregulation of P56{sup Lck}, ZAP-70, and LAT in NCHA cells. AP-1 binding activity was also reduced in NCHA cells. LAT and c-Jun suppressed in NCHA cells were highly induced after PMA treatment. In epigenetic analysis, other signal transduction molecules which are associated with active and/or latent HIV-1 infection showed normal states in HIV-1 latently infected cells compared to A3.01 cells. In conclusion, we demonstrated that the HIV-1 latent state is sustained by the reduction of downstream signaling molecules via the downregulation of CD4 and the attenuated activity of transcription factor as AP-1. The HIV-1 latency model via T-cell deactivation may provide some clues for the development of the new

  19. Colloid migration in porous media

    International Nuclear Information System (INIS)

    Hunt, J.R.; McDowell-Boyer; Sitar, N.

    1985-01-01

    Retention of radionuclides for long periods near waste repositories depends upon multiple barriers, one of which is adsorption to immobile solid surfaces. Since small particles and colloidal matter have high adsorption capacities per unit mass and can be mobile in subsurface flows, colloidal transport of waste components requires analysis. Theories for predicting colloid migration through porous media have been developed in the filtration literature. The applicability of filtration theories for predicting particle and colloid transport. Emphasis is on suspended matter much smaller than pore sizes, where physical and chemical forces control migration rather than size dependent physical straining. In general, experimentally verifiable theories exist for particle filtration by clean media, and a sensitivity analysis is possible on particle and media properties and fluid flow rate. When particle aggregates accumulate within pores, media permeability decreases, resulting in flow field alteration and possible radionuclide isolation. An analysis of the limited experimental data available indicates that present theories cannot predict long-term colloid transport when permeability reduction occurs. The coupling of colloid attachment processes and the hydrologic flow processes requires more extensive laboratory field research than has currently been carried out. An emphasis on the fundamental mechanisms is necessary to enhance long-term predictability

  20. Modelling collective cell migration of neural crest.

    Science.gov (United States)

    Szabó, András; Mayor, Roberto

    2016-10-01

    Collective cell migration has emerged in the recent decade as an important phenomenon in cell and developmental biology and can be defined as the coordinated and cooperative movement of groups of cells. Most studies concentrate on tightly connected epithelial tissues, even though collective migration does not require a constant physical contact. Movement of mesenchymal cells is more independent, making their emergent collective behaviour less intuitive and therefore lending importance to computational modelling. Here we focus on such modelling efforts that aim to understand the collective migration of neural crest cells, a mesenchymal embryonic population that migrates large distances as a group during early vertebrate development. By comparing different models of neural crest migration, we emphasize the similarity and complementary nature of these approaches and suggest a future direction for the field. The principles derived from neural crest modelling could aid understanding the collective migration of other mesenchymal cell types. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Theories of international labor migration: an overview.

    Science.gov (United States)

    Stahl, C W

    1995-01-01

    "Emigration pressures are primarily the result of increasing inequalities between countries which, in turn, are the result of factors internal to less developed countries and their relations with developed countries. Both micro (neoclassical) and macrostructural theories of migration are reviewed. It is argued that the neoclassical theory of migration is often unjustly criticized and is sufficiently robust to incorporate those structural considerations which are at the core of macrostructural theories. Moreover, the neoclassical theory, with slight modification, can incorporate the ¿new economics of migration.' The major empirical problem confronting models of international labor migration is that migration flows are constrained by immigration policy. This policy, in turn, is influenced by various special interest groups. The direction and form of migration flows is conditioned by contemporary and historical relationships between source and destination countries." excerpt

  2. Globalisation and international migration in Asia.

    Science.gov (United States)

    Hugo, G

    1998-03-01

    "The present paper attempts to summarise the major contemporary trends in international migration in Asia and how this is related to the rapid demographic transition occurring across most of the region. The diversity of types of mobility is one of the striking features of Asian international migration and developments in each major type [are] discussed in the paper. It is then argued that there are elements within the Asian migration system that give it a momentum which to some extent operates outside of the influence of economic and political trends. Finally some emerging issues in Asian international migration are briefly addressed. These include the scale and effects of remittances, the feminisation of migration, undocumented migration, increasing government involvement and brain drain issues." (EXCERPT)

  3. Migration in Asia-Europe Relations

    DEFF Research Database (Denmark)

    Juego, Bonn

    2010-01-01

    There is a remarkable difference between viewing migration as a 'social integration' issue, on the one hand, and migration as a 'social relation'. The idea of ‘social integration’ has unrealistic assumptions that see migration as a one-way process, that societies and human relations are static......, and that migrants are mechanical. Policies that are founded on unrealistic assumptions are most likely to generate tensions, conflicts, and contradictions. For a migration process to succeed in forging social harmony and development, it is therefore of decisive and crucial importance to regard migration...... as a ‘social relation’. This is simply because successful migration has to be a harmonious synergy between the migrants (and also the sending countries where they come from) and the receiving society (and its people). As indicated, migrants enter into the receiving society not merely as a passive commodity...

  4. Political motivations for intra-European migration.

    Science.gov (United States)

    Bygnes, Susanne; Flipo, Aurore

    2017-08-01

    Motivations for migrating within the European Union have mainly been attributed to economic, career and lifestyle choices. This article suggests that political dissatisfaction is also an important motivator of recent intra-European migration. In our analysis of in-depth interviews with Romanian migrants in Spain and with Spanish migrants in Norway, we found a common emphasis on the political dimensions of their decision to migrate. In the interviews, the economic component of migration was often related to bad governance and negative perceptions of the state. The similarities of Spanish and Romanian migration narratives are especially striking because Spain and Romania represent substantially different migratory, political and economic contexts. However, migration is more obviously intertwined with conventional acts of political protest in the Spanish case. We suggest that differences in democratic contexts are pivotal in people's reactions to and framing of their deep dissatisfaction with domestic politics, as found in many European countries today.

  5. Multiscale Cues Drive Collective Cell Migration

    Science.gov (United States)

    Nam, Ki-Hwan; Kim, Peter; Wood, David K.; Kwon, Sunghoon; Provenzano, Paolo P.; Kim, Deok-Ho

    2016-07-01

    To investigate complex biophysical relationships driving directed cell migration, we developed a biomimetic platform that allows perturbation of microscale geometric constraints with concomitant nanoscale contact guidance architectures. This permits us to elucidate the influence, and parse out the relative contribution, of multiscale features, and define how these physical inputs are jointly processed with oncogenic signaling. We demonstrate that collective cell migration is profoundly enhanced by the addition of contract guidance cues when not otherwise constrained. However, while nanoscale cues promoted migration in all cases, microscale directed migration cues are dominant as the geometric constraint narrows, a behavior that is well explained by stochastic diffusion anisotropy modeling. Further, oncogene activation (i.e. mutant PIK3CA) resulted in profoundly increased migration where extracellular multiscale directed migration cues and intrinsic signaling synergistically conspire to greatly outperform normal cells or any extracellular guidance cues in isolation.

  6. The Phosphorylation and Distribution of Cortactin Downstream of Integrin α9β1 Affects Cancer Cell Behaviour

    DEFF Research Database (Denmark)

    Høye, Anette M; Couchman, John R; Wewer, Ulla M

    2016-01-01

    Integrins, a family of heterodimeric adhesion receptors are implicated in cell migration, development and cancer progression. They can adopt conformations that reflect their activation states and thereby impact adhesion strength and migration. Integrins in an intermediate activation state may be ...

  7. CD155/PVR plays a key role in cell motility during tumor cell invasion and migration

    International Nuclear Information System (INIS)

    Sloan, Kevin E; Ilag, Leodevico L; Jay, Daniel G; Eustace, Brenda K; Stewart, Jean K; Zehetmeier, Carol; Torella, Claudia; Simeone, Marina; Roy, Jennifer E; Unger, Christine; Louis, David N

    2004-01-01

    Invasion is an important early step of cancer metastasis that is not well understood. Developing therapeutics to limit metastasis requires the identification and validation of candidate proteins necessary for invasion and migration. We developed a functional proteomic screen to identify mediators of tumor cell invasion. This screen couples Fluorophore Assisted Light Inactivation (FALI) to a scFv antibody library to systematically inactivate surface proteins expressed by human fibrosarcoma cells followed by a high-throughput assessment of transwell invasion. Using this screen, we have identified CD155 (the poliovirus receptor) as a mediator of tumor cell invasion through its role in migration. Knockdown of CD155 by FALI or by RNAi resulted in a significant decrease in transwell migration of HT1080 fibrosarcoma cells towards a serum chemoattractant. CD155 was found to be highly expressed in multiple cancer cell lines and primary tumors including glioblastoma (GBM). Knockdown of CD155 also decreased migration of U87MG GBM cells. CD155 is recruited to the leading edge of migrating cells where it colocalizes with actin and αv-integrin, known mediators of motility and adhesion. Knockdown of CD155 also altered cellular morphology, resulting in cells that were larger and more elongated than controls when plated on a Matrigel substrate. These results implicate a role for CD155 in mediating tumor cell invasion and migration and suggest that CD155 may contribute to tumorigenesis

  8. Hydrogen migration in Lu at low temperatures

    International Nuclear Information System (INIS)

    Yamakawa, K.

    1997-01-01

    The migration of hydrogen in Lu is determined by electrical resistance measurements in temperature range of 140-170 K. Disordered hydrogen atoms, which are formed by quenching, migrate to order during annealing in the above temperature range. The rate of the resistance decrease depends on the ordering rate of hydrogen. From the resistance decrease during isothermal annealings, the activation energy of hydrogen migration is determined as 0.43 eV (41.5 kJ mol -1 ). (orig.)

  9. Elastic least-squares reverse time migration

    KAUST Repository

    Feng, Zongcai; Schuster, Gerard T.

    2016-01-01

    Elastic least-squares reverse time migration (LSRTM) is used to invert synthetic particle-velocity data and crosswell pressure field data. The migration images consist of both the P- and Svelocity perturbation images. Numerical tests on synthetic and field data illustrate the advantages of elastic LSRTM over elastic reverse time migration (RTM). In addition, elastic LSRTM images are better focused and have better reflector continuity than do the acoustic LSRTM images.

  10. Cesium migration in LMFBR fuel pins

    International Nuclear Information System (INIS)

    Karnesky, R.A.; Jost, J.W.; Stone, I.Z.

    1978-10-01

    The factors affecting the axial migration of cesium in mixed oxide fuel pins and the effects of cesium migration on fuel pin performance are examined. The development and application of a correlated model which will predict the occurrence of cesium migration in a mixed oxide (75 w/o UO 2 + 25 w/o PuO 2 ) fuel pins over a wide range of fabrication and irradiation conditions are described

  11. The mechanism for migration in Poland.

    Science.gov (United States)

    Rykiel, Z

    1988-01-01

    The author reviews neoclassical theories and models of migration. The mobility theory, which concerns the impact of local labor markets on migration, is discussed in the Polish context. A general model of the regional labor market and a multicausal model are developed to explain the patterns of internal migration. The period of a managed economy (1949-1980) is contrasted with the period since the implementation of a new economic system in 1983.

  12. Internal migration and income of immigrant families

    OpenAIRE

    Rashid, Saman

    2004-01-01

    Using a longitudinal dataset from the years 1995 and 2000, respectively, this study examines whether migration within the host country of Sweden generates higher total annual income for (two-earner) immigrant families. The empirical findings indicate that internal migration generates a positive outcome in terms of higher family income for newly arrived refugee-immigrant families. Further, with the length of residence in the host country, the monetary gain accruing from internal migration decr...

  13. Climate Variability and Migration: Evidence from Tanzania

    OpenAIRE

    Mathilde MAUREL; Zaneta KUBIK

    2014-01-01

    We analyze whether Tanzanian households engage in internal migration as a response to weather-related shocks. Our findings confirm that climate shocks lead to a higher probability of migration by reducing agricultural yields, which in turn induces households to send their members away in order to spatially diversify their income. This effect is, however, low, since a 1% reduction in agricultural income induced by weather shock increases the probability of migration by 3% for an average househ...

  14. RSA migration of total knee replacements.

    Science.gov (United States)

    Pijls, Bart G; Plevier, José W M; Nelissen, Rob G H H

    2018-06-01

    Purpose - We performed a systematic review and meta-analyses to evaluate the early and long-term migration patterns of tibial components of TKR of all known RSA studies. Methods - Migration pattern was defined as at least 2 postoperative RSA follow-up moments. Maximal total point motion (MTPM) at 6 weeks, 3 months, 6 months, 1 year, 2 years, 5 years, and 10 years were considered. Results - The literature search yielded 1,167 hits of which 53 studies were included, comprising 111 study groups and 2,470 knees. The majority of the early migration occurred in the first 6 months postoperatively followed by a period of stability, i.e., no or very little migration. Cemented and uncemented tibial components had different migration patterns. For cemented tibial components there was no difference in migration between all-poly and metal-backed components, between mobile bearing and fixed bearing, between cruciate retaining and posterior stabilized. Furthermore, no difference existed between TKR measured with model-based RSA or marker-based RSA methods. For uncemented TKR there was some variation in migration with the highest migration for uncoated TKR. Interpretation - The results from this meta-analysis on RSA migration of TKR are in line with both the survival analyses results from joint registries of these TKRs as well as revision rates results from meta-analyses, thus providing further proof for the association between early migration and late revision for loosening. The pooled migration patterns can be used both as benchmarks and for defining migration thresholds for future evaluation of new TKR.

  15. Elastic least-squares reverse time migration

    KAUST Repository

    Feng, Zongcai

    2016-09-06

    Elastic least-squares reverse time migration (LSRTM) is used to invert synthetic particle-velocity data and crosswell pressure field data. The migration images consist of both the P- and Svelocity perturbation images. Numerical tests on synthetic and field data illustrate the advantages of elastic LSRTM over elastic reverse time migration (RTM). In addition, elastic LSRTM images are better focused and have better reflector continuity than do the acoustic LSRTM images.

  16. Navigational Strategies of Migrating Monarch Butterflies

    Science.gov (United States)

    2014-11-10

    AFRL-OSR-VA-TR-2014-0339 NAVIGATIONAL STRATEGIES OF MIGRATING MONARCH BUTTERFLIES Steven Reppert UNIVERSITY OF MASSACHUSETTS Final Report 11/10/2014...Final Progress Statement to (Dr. Patrick Bradshaw) Contract/Grant Title: Navigational Strategies of Migrating Monarch Butterflies Contract...Grant #: FA9550-10-1-0480 Reporting Period: 01-Sept-10 to 31-Aug-14 Overview of accomplishments: Migrating monarch butterflies (Danaus

  17. QUALIFIED VERSION OF MIGRATION: BRAIN DRAIN

    OpenAIRE

    Gencler, Ayhan

    2009-01-01

    Though globalization suggests an international exchange of people besides goods and capital, developed countries often tended to put forward some restrictions on the migration of workers from developed countries. However, there has been an increase in skilled international migration especially during the last two decades. Skilled international migration or brain drain points out the emigration of educated and highly skilled workers. It seems that, in general, developing or underdeveloped...

  18. Monitoring of downstream salmon and steelhead at federal hydroelectric facilities -- 1995. Annual report 1995

    International Nuclear Information System (INIS)

    Martinson, R.D.; Graves, R.J.; Langeslay, M.J.; Killins, S.D.

    1996-12-01

    The seaward migration of juvenile salmonids was monitored by the National Marine Fisheries Service (NMFS) at Bonneville and John Day Dams on the Columbia river in 1995. The NMFS Smolt Monitoring Project is part of a larger Smolt Monitoring Program (SMP) coordinated by the Fish Passage Center (FPC) for the Columbia Basin Fish and Wildlife Authority. This program focuses on protecting, mitigating, and enhancing fish populations affected by the development and operation of hydroelectric power plants on the Columbia River. The purpose of the SMP is to monitor the migration of the juvenile salmonid stocks in the Columbia basin and make flow and spill recommendations designed to facilitate fish passage. Data are also used for travel time, migration timing, and relative run size analysis. The purpose of the NMFS portion of the program is to provide FPC with species and project specific real time data from John Day and Bonneville Dams

  19. Monitoring of downstream salmon and steelhead at federal hydroelectric facilities - 1996. Annual report

    International Nuclear Information System (INIS)

    Martinson, R.D.; Graves, R.J.; Mills, R.B.; Kamps, J.W.

    1997-08-01

    The seaward migration of juvenile salmonids was monitored by the National Marine Fisheries Service (NMFS) at Bonneville and John Day Dams on the Columbia River in 1996 The NMFS Smolt Monitoring Project is part of a larger Smolt Monitoring Program (SMP) coordinated by the Fish Passage Center (FPC) for the Columbia Basin Fish and Wildlife Authority. The purpose of the SMP is to monitor the migration of the juvenile salmonid stocks in the Columbia basin and make flow and spill recommendations designed to facilitate fish passage. Data are also used for travel time, migration timing, and relative run size analysis. The purpose of the NMFS portion of the program is to provide the FPC with species and project specific real time data from John Day and Bonneville Dams. Monitoring data collected included: river conditions; total numbers of fish; numbers of fry, adult salmon, and incidental catch; daily and seasonal passage patterns; and fish condition. 10 refs., 16 figs., 5 tabs

  20. Gene expression programming for prediction of scour depth downstream of sills

    Science.gov (United States)

    Azamathulla, H. Md.

    2012-08-01

    SummaryLocal scour is crucial in the degradation of river bed and the stability of grade control structures, stilling basins, aprons, ski-jump bucket spillways, bed sills, weirs, check dams, etc. This short communication presents gene-expression programming (GEP), which is an extension to genetic programming (GP), as an alternative approach to predict scour depth downstream of sills. Published data were compiled from the literature for the scour depth downstream of sills. The proposed GEP approach gives satisfactory results (R2 = 0.967 and RMSE = 0.088) compared to the existing predictors (Chinnarasri and Kositgittiwong, 2008) with R2 = 0.87 and RMSE = 2.452 for relative scour depth.

  1. Re-modulated technology of WDM-PON employing different DQPSK downstream signals

    Science.gov (United States)

    Gao, Chao; Xin, Xiang-jun; Yu, Chong-xiu

    2012-11-01

    This paper proposes a kind of modulation architecture for wavelength-division-multiplexing passive optical network (WDMPON) employing optical differential quadrature phase shift keying (DQPSK) downstream signals and two different modulation formats of re-modulated upstream signals. At the optical line terminal (OLT), 10 Gbit/s signal is modulated with DQPSK. At the optical network unit (ONU), part of the downstream signal is re-modulated with on-off keying (OOK) or inverse-return-to-zero (IRZ). Simulation results show the impact on the system employing NRZ, RZ and carrier-suppressed return-to-zero (CSRZ). The analyses also reflect that the architecture can restrain chromatic dispersion and channel crosstalk, which makes it the best architecture of access network in the future.

  2. Circadian rhythms in healthy aging--effects downstream from the pacemaker

    Science.gov (United States)

    Monk, T. H.; Kupfer, D. J.

    2000-01-01

    Using both previously published findings and entirely new data, we present evidence in support of the argument that the circadian dysfunction of advancing age in the healthy human is primarily one of failing to transduce the circadian signal from the circadian timing system (CTS) to rhythms "downstream" from the pacemaker rather than one of failing to generate the circadian signal itself. Two downstream rhythms are considered: subjective alertness and objective performance. For subjective alertness, we show that in both normal nychthemeral (24 h routine, sleeping at night) and unmasking (36 h of constant wakeful bed rest) conditions, advancing age, especially in men, leads to flattening of subjective alertness rhythms, even when circadian temperature rhythms are relatively robust. For objective performance, an unmasking experiment involving manual dexterity, visual search, and visual vigilance tasks was used to demonstrate that the relationship between temperature and performance is strong in the young, but not in older subjects (and especially not in older men).

  3. Beam Halo on the LHC TCDQ Diluter System and Thermal Load on the Downstream Superconducting Magnets

    CERN Document Server

    Goddard, B; Presland, A; Redaelli, S; Robert-Démolaize, G; Sarchiapone, L; Weiler, T; Weterings, W

    2006-01-01

    The moveable single-jawed graphite TCDQ diluter must be positioned very close to the circulating LHC beam in order to prevent damage to downstream components in the event of an unsynchronised beam abort. A two-jawed graphite TCS.IR6 collimator forms part of the TCDQ system. The requirement to place the jaws close to the beam means that the system can intercept a substantial beam halo load. Initial investigations indicated a worryingly high heat load on the Q4 coils. This paper presents the updated load cases, shielding and simulation geometry, and the results of simulations of the energy deposition in the TCDQ system and in the downstream superconducting Q4 magnet. The implications for the operation of the LHC are discussed.

  4. A novel cell autolysis system for cost-competitive downstream processing.

    Science.gov (United States)

    Hajnal, Ivan; Chen, Xiangbin; Chen, Guo-Qiang

    2016-11-01

    The industrial production of low value-added biological products poses significant challenges due to cost pressures. In recent years, it has been argued that synthetic biology approaches will lead to breakthroughs that eliminate price bottlenecks for the production of a wide range of biological products including bioplastics and biofuels. One significant bottleneck lies in the necessity to break the tough cell walls of microbes in order to release intracellular products. We here report the implementation of the first synthetic biology standard part based on the lambda phage SRRz genes and a synthetic ribosome binding site (RBS) that works in Escherichia coli and Halomonas campaniensis, which enables the producer strains to induce lysis after the addition of small amounts (1-5 %) of solvents or to spontaneously lyse during the stresses of downstream processing, and thus has the potential to eliminate the mechanical cell disruption step as both an efficiency bottleneck and a significant capex barrier when implementing downstream bioprocesses.

  5. Impact of upstream and downstream constraints on a signaling module’s ultrasensitivity

    International Nuclear Information System (INIS)

    Altszyler, Edgar; Chernomoretz, Ariel; Ventura, Alejandra; Colman-Lerner, Alejandro

    2014-01-01

    Much work has been done on the study of the biochemical mechanisms that result in ultrasensitive behavior of simple biochemical modules. However, in a living cell, such modules are embedded in a bigger network that constrains the range of inputs that the module will receive as well as the range of the module’s outputs that network will be able to detect. Here, we studied how the effective ultrasensitivity of a modular system is affected by these restrictions. We use a simple setup to explore to what extent the dynamic range spanned by upstream and downstream components of an ultrasensitive module impact on the effective sensitivity of the system. Interestingly, we found for some ultrasensitive motifs that dynamic range limitations imposed by downstream components can produce effective sensitivities much larger than that of the original module when considered in isolation. (paper)

  6. Measurements of energy spectra of fast electrons from PF-1000 in the upstream and downstream directions

    Energy Technology Data Exchange (ETDEWEB)

    Kwiatkowski, R.; Czaus, K.; Skladnik-Sadowska, E.; Malinowski, K.; Zebrowski, J. [The Andrzej Soltan Institute for Nuclear Studies (IPJ), 05-400 Otwock-Swierk (Poland); Sadowski, M.J. [The Andrzej Soltan Institute for Nuclear Studies (IPJ), 05-400 Otwock-Swierk (Poland); Karpinski, L.; Paduch, M.; Scholz, M. [Institute of Plasma Physics and Laser Microfusion (IPPLM), 01-497 Warsaw (Poland); Kubes, P. [Czech Technical University (CVUT), 166-27 Prague, (Czech Republic)

    2011-07-01

    The paper describes measurements of energy spectra of electrons emitted in the upstream direction along the symmetry-axis of the PF-1000 facility, operated with the deuterium filling at 21 kV, 290 kJ. The measurements were performed with a magnetic analyzer. The same analyzer was used to measure also electron beams emitted in along the symmetry-axis in the downstream direction. The recorded spectra showed that the electron-beams emitted in the upstream direction have energies in the range from about 40 keV to about 800 keV, while those in the downstream direction have energies in the range from about 60 keV to about 200 keV. These spectra confirm that in the PF (Plasma Focus) plasma column there appear strong local fields accelerating charged particles in different directions. This document is composed of a paper and a poster. (authors)

  7. Sources for increased DOC-concentrations in the groundwater downstream of the landfill Hohne (DEA)

    International Nuclear Information System (INIS)

    Bahlmann, E.; Seifert, R.; Eschenbach, A.; Kleinschmidt, V.

    2017-08-01

    Construction waste together with drilling mud and oil-contaminated soil had been deposited in the landfill Hohne from 1971. Four groundwater monitoring sites had been installed: one monitoring site upstream and three sites downstream of the landfill in three different directions. Downstream of the landfill increased concentrations of chloride, sulphate, sodium and DOC (dissolved organic carbon) had been measured over a period of years. Particularly the source of the DOC has remained unclear. Assumptions were (i) leaking of contaminants from the landfill and degradation under the landfill by microbes or plants or (ii) leaching of DOC from the soil under the landfill caused by a change in the redox potential. The determination of the DOC source was the major subject of this study.

  8. Comparative Study on Migration, Urbanization and Development in the ESCAP Region (RAS/P13/79). Rev. version.

    Science.gov (United States)

    1982-01-01

    Development of a study project by the UN Economic and Social Commission for Asia and the Pacific (ESCAP) on migration, urbanization, and development in the following countries is described: Indonesia, Malaysia, Pakistan, Philippines, Republic of Korea, Sri Lanka, and Thailand. The project's immediate goal is to assist decision makers in formulating population redistribution policies. It was recommended that ESCAP develop and test a migration questionnaire to assist member countries in undertaking surveys to study the interrelationships of migration and development. Upon completion of survey manuals to assist in the survey implementation, it was suggested that ESCAP run a series of in-country workshops to discuss the applications of survey results for policy formulation. A national migration survey will be taken in each country in the early 1980s in order to discern pattern and type of population mobility, factors that cause people to move or not to move, and the consequences of migration on places of origin and destination. A sample of 14,000 households in each country will be selected and 1 person of age 15-64 will be chosen as the respondent for each household. the following are some items which will be studied: 1) volume of migration streams within and between metropolitan areas and urban-rural areas; 2) decision making factors; 3) interactions between population movement and family structure, chages in fertility levels, employment, and education; 4) impact of agricultural systems on seasonal movements; 5) contributions of migrants to the cities; and 6) implications of international migration to and from the country. Leading family planning agencies will use these results to develop policy relating to population distribution, industry location, migration laws, regional economic planning, modern technology, and rural education. The management framework of the project is presented. After these results are published, government agencies can utilize them by

  9. International migration: The state-sovereignty-migration nexus

    Directory of Open Access Journals (Sweden)

    D. Chigudu

    2015-12-01

    Full Text Available Commonly, international human migration is blamed for corroding states sovereignty, especially stemming from policy circles, academic literature and citizens of the host countries. This has attracted the attention of the media highlighting hazards of being a migrant, with some countries viewing migrants as enemies; and, Cuba provides a vivid case. Yet in other countries, migrants are viewed as important contributors to social and economic development, with Mexico, the Dominican Republic and India serving as examples. This article locates migrants in the framework of human rights as guided by international law without prejudice to the demands of state sovereignty, but linking the two in the context of developing international standards. Migration is seen as a feature of human history dating back to primordial time. Nothing appears surprising in the movement of people across borders, defining a migrant through emigration and immigration while giving due respect to the sovereignty of states, both sending and receiving. The article discusses the nexus between migrants and state sovereignty in order to highlight the mutual benefit grounded in international law. It attempts to portray a more positive image of the migrant person in light of the global world, socio-economic development and human rights fundamentals. The main challenge remains that of implementing human rights, which appear to be at the crossroads of individual rights and state sovereignty. The paper reveals how the challenge can be overcome while maintaining the structure of rights and freedoms without infringement on states’ sovereignty. It concludes that migrants remain on the periphery of effective protection from the vagaries of the citizens, partly because the state has a tendency to confine certain rights to its citizenry. States possess discretionary authority to control the ingress of foreign nationals into their territories though sometimes they fail to do that as evidenced

  10. Demographic situation and population migration problems

    International Nuclear Information System (INIS)

    1993-01-01

    Problem of the Chernobyl accident effect on the population migration in controlled areas of the Ukraine, Belarus and in Russian Federation. Comparison of the data on migration for 1990 and for 1995 has shown considerable growth of the intensity of efflux of rural population at most Ukrainian areas affected due to the Chernobyl accident. Negative migration growth in urban settlements of these regions is marked. Decrease in rural resident migration is observed. Migrant current in Russia is twice increased. Main regions of North-West, Central, North-Caucasus ones in Russia and Donetsk-Dnieper river in the Ukraine. 6 tabs

  11. [Migration mobility and movement of the population].

    Science.gov (United States)

    Zaslavska, T; Ribakovski, L

    1983-01-01

    "The functions of migration are reviewed from the viewpoint of the demographic situation in the USSR (by regions, sex, age, education, profession, labour and social activity, nationality, rural-urban, etc.). Some effects of migration on fertility are shown. The authors investigate the role of the economic functions of migration for the process of professional mobility. The territorial mobility of the population is analysed on a wider scale as a part of the social mobility in the socialist society. In connection with this, some problems of the migration policy as an element of the demographic policy of the USSR are outlined." (summary in ENG, RUS) excerpt

  12. Nuss bar migrations: occurrence and classification

    International Nuclear Information System (INIS)

    Binkovitz, Lauren E.; Binkovitz, Larry A.; Zendejas, Benjamin; Moir, Christopher R.

    2016-01-01

    Pectus excavatum results from dorsal deviation of the sternum causing narrowing of the anterior-posterior diameter of the chest. It can result in significant cosmetic deformities and cardiopulmonary compromise if severe. The Nuss procedure is a minimally invasive technique that involves placing a thin horizontally oriented metal bar below the dorsal sternal apex for correction of the pectus deformity. To identify the frequency and types of Nuss bar migrations, to present a new categorization of bar migrations, and to present examples of true migrations and pseudomigrations. We retrospectively reviewed the electronic medical records and all pertinent radiologic studies of 311 pediatric patients who underwent a Nuss procedure. We evaluated the frequency and type of bar migrations. Bar migration was demonstrated in 23 of 311 patients (7%) and occurred within a mean period of 26 days after surgery. Bar migrations were subjectively defined as deviation of the bar from the position demonstrated on the immediate postoperative radiographs and categorized as superior, inferior, rotation, lateral or flipped using a new classification system. Sixteen of the 23 migrations required re-operation. Nuss bar migration can be diagnosed with careful evaluation of serial radiographs. Nuss bar migration has a wide variety of appearances and requires exclusion of pseudomigration resulting from changes in patient positioning between radiologic examinations. (orig.)

  13. The migration of uranium through sandstone

    International Nuclear Information System (INIS)

    Bennett, D.G.; Read, D.; Lawless, T.A.; Sims, R.J.

    1992-01-01

    Three column experiments are described in which the migration of uranium through Clashach Sandstone was studied. A priori predictions of uranium migration in the experiments were made using an equilibrium chemical transport model. The experimental results showed that, even under oxidising conditions, the migration of uranium is strongly retarded owing to the affinity of uranium for mineral surfaces. For the relatively simple chemical system investigated, the chemical transport model was successful in predicting the migration of uranium and its distribution along the column. (author)

  14. Migration processes in SCO member states

    Directory of Open Access Journals (Sweden)

    Valentina Sergeevna Antonyuk

    2012-12-01

    Full Text Available The article concerns modern state and development of migration processes in SCO member states. As a main method of research statistical analysis was applied. The article shows that migration streams between SCO member states are rather intensive, and the problem of labor migration becomes more and more urgent. The countries of consuming and supplying of labour force are clearly differentiated in the region. For some countries, labor export is the key sector of economy. At the same time, interstate relations between SCO member states sometimes are rather disputed. The most urgent factors causing the development of migration processes in the region were determined. Among them, thefactor of growing outflows from China isespecially noted. It is noted that migration processes are discussed by SCO member states nowadays in terms of illegal migration and international criminality connected with it. It means that the question of labor migration is a real problem. It is indicated that the creation of a specific joint commission on migration policy affiliated with the Council of Foreign Ministers of SCO member states is the necessary condition of effective interaction in migration questions within the framework of Shanghai Cooperation Organization.

  15. Motorized Migrations: the Future or Mere Fantasy?

    Science.gov (United States)

    Ellis, D.H.; Sladen, William J. L.; Lishman, W.A.; Clegg, K.R.; Duff, J.W.; Gee, G.F.; Lewis, J.C.

    2003-01-01

    In 15 experiments from 1993-2002, we led cranes, geese, or swans on their first southward migration with either ultralight aircraft or vehicles on the ground. These experiments reveal that large birds can be readily trained to follow and most will return north (and south) in subsequent migrations unassisted. These techniques can now be used to teach birds new (or forgotten) migration paths. Although we are constantly improving our training techniques, we now have an operational program that can be broadly applied to those species where juveniles learn migration routes from their parents.

  16. Nuss bar migrations: occurrence and classification

    Energy Technology Data Exchange (ETDEWEB)

    Binkovitz, Lauren E.; Binkovitz, Larry A. [Mayo Clinic, Department of Radiology, Rochester, MN (United States); Zendejas, Benjamin; Moir, Christopher R. [Mayo Clinic, Department of Surgery, Rochester, MN (United States)

    2016-12-15

    Pectus excavatum results from dorsal deviation of the sternum causing narrowing of the anterior-posterior diameter of the chest. It can result in significant cosmetic deformities and cardiopulmonary compromise if severe. The Nuss procedure is a minimally invasive technique that involves placing a thin horizontally oriented metal bar below the dorsal sternal apex for correction of the pectus deformity. To identify the frequency and types of Nuss bar migrations, to present a new categorization of bar migrations, and to present examples of true migrations and pseudomigrations. We retrospectively reviewed the electronic medical records and all pertinent radiologic studies of 311 pediatric patients who underwent a Nuss procedure. We evaluated the frequency and type of bar migrations. Bar migration was demonstrated in 23 of 311 patients (7%) and occurred within a mean period of 26 days after surgery. Bar migrations were subjectively defined as deviation of the bar from the position demonstrated on the immediate postoperative radiographs and categorized as superior, inferior, rotation, lateral or flipped using a new classification system. Sixteen of the 23 migrations required re-operation. Nuss bar migration can be diagnosed with careful evaluation of serial radiographs. Nuss bar migration has a wide variety of appearances and requires exclusion of pseudomigration resulting from changes in patient positioning between radiologic examinations. (orig.)

  17. QUALIFIED VERSION OF MIGRATION: BRAIN DRAIN

    Directory of Open Access Journals (Sweden)

    Ayhan GENCLER

    2009-07-01

    Full Text Available Though globalization suggests an international exchange of people besides goods and capital, developed countries often tended to put forward some restrictions on the migration of workers from developed countries. However, there has been an increase in skilled international migration especially during the last two decades. Skilled international migration or brain drain points out the emigration of educated and highly skilled workers. It seems that, in general, developing or underdeveloped countries experience the negative consequences of the brain drain and suffer from the decreases in their human capital. The paper explains the phenomenon of skilled international migration, or brain drain, and summarizes the main global trends in this area.

  18. Ontogenetic behavior, migration, and social behavior of pallid sturgeon, Scaphirhynchus albus, and shovelnose sturgeon, S. platorynchus, with notes on the adaptive significance of body color

    Science.gov (United States)

    Kynard, B.; Henyey, E.; Horgan, M.

    2002-01-01

    We conducted laboratory studies on the ontogenetic behavior of free embryos (first life interval after hatching) and larvae (first feeding interval) of pallid and shovelnose sturgeon. Migration styles of both species were similar for timing of migration (initiation by embryos on day 0 after hatching and cessation by larvae on days 12-13 at 236-243 cumulative temperature degree units), migration distance (about 13 km), life interval when most distance was moved (embryo), and diel behavior of embryos (diurnal). However, the species differed for two behaviors: movement characteristics of embryos (peak movement rate of pallid sturgeon was only one-half the peak rate of shovelnose sturgeon, but pallid sturgeon continued the lower rate for twice as long) and diel behavior of larvae (pallid sturgeon were diurnal and shovelnose sturgeon were nocturnal). Thus, the species used different methods to move the same distance. Migrating as poorly developed embryos suggests a migration style to avoid predation at the spawning site, but moving from spawning habitat to rearing habitat before first feeding could also be important. Migrants of both species preferred bright habitat (high illumination intensity and white substrate), a behavioral preference that may characterize the migrants of many species of sturgeon. Both species were remarkably similar for swimming height above the bottom by age, and day 7 and older migrants may swim far above the bottom and move far downstream. A migration of 12 or 13 days will probably not distribute larvae throughout the population's range, so an older life interval likely initiates a second longer downstream migration (2-step migration). By day 2, individuals of both species were a black-tail phenotype (light grey body with a black-tail that moved conspicuously during swimming). Aggregation behavior suggests that black-tail is a visual signal used for group cohesion.

  19. Quantifying the Impact of geographically isolated wetlands on the downstream hydrology of a Canadian Prairie watershed

    Science.gov (United States)

    Muhammad, A.; Evenson, G. R.; Boluwade, A.; Jha, S. K.; Rasmussen, P. F.

    2016-12-01

    Hydrological processes are highly complex and strongly nonlinear and cannot be represented through simple means. Models are built to replicate these processes. However, models due to various sources of uncertainty including their structural capability often lead to inaccurate results. The aim of this study is to setup the soil water assessment tool (SWAT) for a watershed that is dominated by potholes in the Prairie region of Canada. The potholes not connected to the stream, also known as geographically isolated wetlands (GIWs), are dynamic in nature leading to a fill and spill situation due to varying surface runoff conditions. Significant land use changes have resulted in almost 70% of wetlands being lost and have posed threat of flooding to downstream areas. While some studies were devoted to identify the presence of potholes only few have explored the impacts of wetlands on the downstream hydrology. In this study, we follow Evenson et al., (2016) approach of modifying SWAT model. The modification enhances structural capability of SWAT while depicting the dynamics of wetlands at HRUs level. Redefining the formation of HRUs in such way effectively captures the spatial presence of potholes. We then routed the potholes' fill and spill hydrology to direct the flow to the potholes immediately downstream. The model was calibrated for 2005-2008 and verified over 2009-2011 at a daily time step. We tested our model with three land use change scenarios by varying the presence of potholes and evaluated its impact on the downstream hydrograph. We foresee a significant improvement in replicating stream flow using this novel approach. We believe that it will effectively improve the predictive power of SWAT for this highly complex sub basin (Upper Assiniboine catchment at Kamsack) located in Canadian Prairie.

  20. Wave propagation downstream of a high power helicon in a dipolelike magnetic field

    International Nuclear Information System (INIS)

    Prager, James; Winglee, Robert; Roberson, B. Race; Ziemba, Timothy

    2010-01-01

    The wave propagating downstream of a high power helicon source in a diverging magnetic field was investigated experimentally. The magnetic field of the wave has been measured both axially and radially. The three-dimensional structure of the propagating wave is observed and its wavelength and phase velocity are determined. The measurements are compared to predictions from helicon theory and that of a freely propagating whistler wave. The implications of this work on the helicon as a thruster are also discussed.