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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.

    Energy Technology Data Exchange (ETDEWEB)

    Perry, Russell W.; Farley, M. Jared; Hansen, Gabriel S. (US Geological Survey, Western Fisheries Research Center, Columbia River Research Laboratory, Cook, WA)

    2005-07-01

    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. 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

  4. Downstream migrating antidunes or in-phase waves?

    Science.gov (United States)

    Núñez González, Francisco

    2014-05-01

    Late back in the beginning of the 20th century, Gilbert observed bedforms that migrated in opposite direction to flow. Since this feature was remarkable and inverse to the behavior of dunes (most often observed in rivers and flumes), he called the new species antidunes. Subsequent researchers identified other characteristic attributes of the new species, and it was later commonly accepted that a defining characteristic of antidunes was that undulations of bed and water profiles were roughly in-phase. Due to its generality, such definition has given place to some ambiguities, particularly when dealing with bedforms close to the critical-supercritical transition, as occurs with bedforms with bed and water profiles roughly in-phase but migrating downstream. Such bedforms are described by different researchers, but they are not always classified as antidunes. Some sedimentologists argue that given the depositional pattern of such streamwise migrating forms is different to that of upstream-migrating antidunes, the more generic term "in-phase waves" should be applied to consider them as a different class. The lack of a stability field for 2D downstream-migrating antidunes in the classical theoretical study of Kennedy in the early sixties, has also contributed to some confusion. According to such theoretical diagram, downstream-migrating antidunes could only exist being 3D, but empirical evidences -even from Kennedy- contradict this outcome. In this work, such results and other morphodynamic features of downstream-migrating antidunes will be discussed, in light of experimental data and a simple hydraulic analysis of the direction of movement of antidunes. An open question will be left to debate about the appropriateness of classifying downstream-migrating in-phase waves as antidunes, and it will be emphasized that finding consensus between different disciplines involved with the study of bedforms will be advantageous.

  5. Downstream-migrating fluvial point bars in the rock record

    Science.gov (United States)

    Ghinassi, Massimiliano; Ielpi, Alessandro; Aldinucci, Mauro; Fustic, Milovan

    2016-04-01

    Classical models developed for ancient fluvial point bars are based on the assumption that meander bends invariably increase their radius as meander-bend apices migrate in a direction transverse to the channel-belt axis (i.e., meander bend expansion). However, many modern meandering rivers are also characterized by down-valley migration of the bend apex, a mechanism that takes place without a significant change in meander radius and wavelength. Downstream-migrating fluvial point bars (DMFPB) are the dominant architectural element of these types of meander belts. Yet they are poorly known from ancient fluvial-channel belts, since their disambiguation from expansional point bars often requires fully-3D perspectives. This study aims to review DMFPB deposits spanning in age from Devonian to Holocene, and to discuss their main architectural and sedimentological features from published outcrop, borehole and 3D-seismic datasets. Fluvial successions hosting DMFPB mainly accumulated in low accommodation conditions, where channel belts were affected by different degrees of morphological (e.g., valleys) or tectonic (e.g., axial drainage of shortening basins) confinement. In confined settings, bends migrate downstream along the erosion-resistant valley flanks and little or no floodplain deposits are preserved. Progressive floor aggradation (e.g., valley filling) allow meander belts with DMFPB to decrease their degree of confinement. In less confined settings, meander bends migrate downstream mainly after impinging against older, erosion-resistant channel fill mud. By contrast, tectonic confinement is commonly associated with uplifted alluvial plains that prevented meander-bend expansion, in turn triggering downstream translation. At the scale of individual point bars, translational morphodynamics promote the preservation of downstream-bar deposits, whereas the coarser-grained upstream and central beds are less frequently preserved. However, enhanced preservation of upstream

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

    DEFF Research Database (Denmark)

    Xu, Xuebing

    1997-01-01

    -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...... to the required products. In this paper, the reasons of acyl migration and factors affecting the acyl migration were reviewed and discussed. The possible solutions were also evaluated....

  7. Physiological and endocrine changes in Atlantic salmon smolts during hatchery rearing, downstream migration and ocean entry

    Science.gov (United States)

    McCormick, Stephen D.; Sheehan, Timothy F.; Björnsson, Björn Thrandur; Lipsky, Christine; Kocik, John F.; Regish, Amy M.; O'Dea, Michael F.

    2013-01-01

    Billions of hatchery salmon smolts are released annually in an attempt to mitigate anthropogenic impacts on freshwater habitats, often with limited success. Mortality of wild and hatchery fish is high during downstream and early ocean migration. To understand changes that occur during migration, we examined physiological and endocrine changes in Atlantic salmon (Salmo salar) smolts during hatchery rearing, downstream migration, and early ocean entry in two successive years. Gill Na+/K+-ATPase activity increased in the hatchery during spring, increased further after river release, and was slightly lower after recapture in the ocean. Plasma growth hormone levels increased in the hatchery, were higher in the river, and increased further in the ocean. Plasma IGF-I remained relatively constant in the hatchery, increased in the river, then decreased in the ocean. Plasma thyroid hormones were variable in the hatchery, but increased in both river- and ocean-captured smolts. Naturally reared fish had lower condition factor, gill NKA activity, and plasma thyroxine than hatchery fish in the river but were similar in the ocean. This novel data set provides a vital first step in understanding the role and norms of endocrine function in smolts and the metrics of successful marine entry.

  8. pna - assisted cellular migration on patterned surfaces

    OpenAIRE

    2013-01-01

    ABSTRACT - The ability to control the cellular microenvironment, such as cell-substrate and cell-cell interactions at the micro- and nanoscale, is important for advances in several fields such as medicine and immunology, biochemistry, biomaterials, and tissue engineering. In order to undergo fundamental biological processes, most mammalian cells must adhere to the underlying extracellular matrix (ECM), eliciting cell adhesion and migration processes that are critical to embryogenesis, angioge...

  9. 17-Beta estradiol and 4-nonylphenol delay smolt development and downstream migration in Atlantic salmon, Salmo salar.

    Science.gov (United States)

    Madsen, Steffen S; Skovbølling, Søren; Nielsen, Christian; Korsgaard, Bodil

    2004-06-10

    The effect of 17-beta estradiol (E2) and 4-nonylphenol (4-NP) on smoltification and downstream migration of Atlantic salmon was studied in an integrated laboratory and field study. In a stock of hatchery-raised 1-year-old salmon, smoltification progressed from February until late May as judged 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 microg/g body weight E2, 120 microg/g 4-NP dissolved in peanut oil or peanut oil (4 microl/g) as control. After the last injection, all fish were individually tagged (Passive Integrated Transponder tags) and a non-lethal gill biopsy was taken. Two days later (8 April), 100 fish per group were transported to the field site and released into a small stream. Smolt migration was registered by measuring arrival time at a trap downstream of the release site. Serum vitellogenin levels increased several-fold in both male and female E2- and 4-NP-treated fish. Overall, E2- and 4-NP-treatment impaired smolting as judged by elevated condition factor, reduced gill Na+, K+ -ATPase activity and alpha-subunit Na+, K+ -ATPase mRNA level, reduced muscle water content and increased mortality following 24 h SW-challenge. After release, control fish initiated downstream migration immediately, with 50% of the total number of migrants appearing in the trap within 10 days. E2- and 4-NP-treated fish appeared in the trap with a delay in comparison to controls of 6 and 8 days, respectively. After the smolt run, no fish were registered by electro-fishing upstream of the trap. The total number of fish reaching the trap and thus post-release survival was in the order control (81%), E2 (53%), 4-NP (12%). Representatives from all treatment groups held under simulated natural conditions in the laboratory survived 100% through the migration period, suggesting that a combination of behavioural and in-stream factors (predation by herons

  10. Ganglioside GM2 mediates migration of tumor cells by interacting with integrin and modulating the downstream signaling pathway.

    Science.gov (United States)

    Kundu, Manjari; Mahata, Barun; Banerjee, Avisek; Chakraborty, Sohini; Debnath, Shibjyoti; Ray, Sougata Sinha; Ghosh, Zhumur; Biswas, Kaushik

    2016-07-01

    The definitive role of ganglioside GM2 in mediating tumor-induced growth and progression is still unknown. Here we report a novel role of ganglioside GM2 in mediating tumor cell migration and uncovered its mechanism. Data shows differential expression levels of GM2-synthase as well as GM2 in different human cancer cells. siRNA mediated knockdown of GM2-synthase in CCF52, A549 and SK-RC-26B cells resulted in significant inhibition of tumor cell migration as well as invasion in vitro without affecting cellular proliferation. Over-expression of GM2-synthase in low-GM2 expressing SK-RC-45 cells resulted in a consequent increase in migration thus confirming the potential role GM2 and its downstream partners play in tumor cell migration and motility. Further, treatment of SK-RC-45 cells with exogenous GM2 resulted in a dramatic increase in migratory and invasive capacity with no change in proliferative capacity, thereby confirming the role of GM2 in tumorigenesis specifically by mediating tumor migration and invasion. Gene expression profiling of GM2-synthase silenced cells revealed altered expression of several genes involved in cell migration primarily those controlling the integrin mediated signaling. GM2-synthase knockdown resulted in decreased phosphorylation of FAK, Src as well as Erk, while over-expression and/or exogenous GM2 treatment caused increased FAK and Erk phosphorylation respectively. Again, GM2 mediated invasion and Erk phosphorylation is blocked in integrin knockdown SK-RC-45 cells, thus confirming that GM2 mediated migration and phosphorylation of Erk is integrin dependent. Finally, confocal microscopy suggested co-localization while co-immunoprecipitation and surface plasmon resonance (SPR) confirmed direct interaction of membrane bound ganglioside, GM2 with the integrin receptor.

  11. 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 deep...... hydroelectric reservoirs. The present study tested the use of a surface orientated travelling screen to guide Atlantic salmon (Salmo salar L.) and brown trout (Salmo trutta L.) smolts past a water abstraction site in a shallow lowland stream. The percentage of total discharge abstracted from the stream...

  12. FMNL2 drives actin-based protrusion and migration downstream of Cdc42

    DEFF Research Database (Denmark)

    Block, Jennifer; Breitsprecher, Dennis; Kühn, Sonja;

    2012-01-01

    Cell migration entails protrusion of lamellipodia, densely packed networks of actin filaments at the cell front. Filaments are generated by nucleation, likely mediated by Arp2/3 complex and its activator Scar/WAVE. It is unclear whether formins contribute to lamellipodial actin filament nucleation...... ends generated by Arp2/3-mediated branching are captured and efficiently elongated by the formin. Consistent with these biochemical properties, RNAi-mediated silencing of FMNL2 expression decreases the rate of lamellipodia protrusion and, accordingly, the efficiency of cell migration. Our data...

  13. Wind assistance: A requirement for migration of shorebirds?

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    Butler, R.W.; Williams, T.D.; Warnock, N.; Bishop, M.A.

    1997-01-01

    We investigated the importance of wind-assisted flight for northward (spring) migration by Western Sandpipers (Calidris mauri) along the Pacific Coast of North America. Using current models of energy costs of flight and recent data on the phenology of migration, we estimated the energy (fat) requirements for migration in calm winds and with wind-assisted flight for different rates of fat deposition: (1) a variable rate, assuming that birds deposit the minimum amount of fat required to reach the next stopover site; (2) a constant maximum rate of 1.0 g/day; and (3) a lower constant rate of 0.4 g/day. We tested these models by comparing conservative estimates of predicted body mass along the migration route with empirical data on body mass of Western Sandpipers at different stopover sites and upon arrival at the breeding grounds. In calm conditions, birds would have to deposit unrealistically high amounts of fat (up to 330% of observed values) to maintain body mass above absolute lean mass values. Fat-deposition rates of 1.0 g/day and 0.4 g/day, in calm conditions, resulted in a steady decline in body mass along the migration route, with predicted body masses on arrival in Alaska of only 60% (13.6 g) and 26% (5.9 g) of average lean mass (22.7 g). Conversely, birds migrating with wind assistance would be able to complete migration with fat-deposition rates as low as 0.4 g/day, similar to values reported for this size bird from field studies. Our results extend the conclusion of the importance of winds for large, long-distance migrants to a small, short-distance migrant. We suggest that the migratory decisions of birds are more strongly influenced by the frequency and duration of winds aloft, i.e. by events during the flight phase, than by events during the stopover phase of migration, such as fat-deposition rate, that have been the focus of much recent migration theory.

  14. 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.

  15. Evaluation of Guiding Device for Downstream Fish Migration with in-Field Particle Tracking Velocimetry and CFD

    Directory of Open Access Journals (Sweden)

    Staffan Lundstrom

    2015-01-01

    Full Text Available The performance of a fish guiding device located just upstream a hydropower plant is scrutinized. The device is designed to redirect surface orientated down-stream migrating fish (smolts away from the turbines towards a spillway that act as a relatively safe fishway. Particles are added up-stream the device and the fraction particles going to the spillway is measured. A two-frame Particle Tracking Velocimetry algorithm is used to derive the velocity field of the water. The experimental results are compared to simulations with CFD. If the smolts move passively as the particles used in the study the guiding device works very well and some modifications may optimize its performance. In-field Particle Tracking Velocimetry is a suitable technique for the current case and the results compare well with numerical simulations.

  16. 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

    The effect of 17-beta estradiol (E2) and 4-nonylphenol (4-NP) on smoltification and downstream migration of Atlantic salmon was studied in an integrated laboratory and field study. In a stock of hatchery-raised 1-year-old salmon, smoltification progressed from February until late May as judged...

  17. 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

  18. Movements and Distribution of Northern Squawfish Downstream of Lower Snake River Dams Relative to the Migration of Juvenile Salmonids, 1992-1993 Completion Report.

    Energy Technology Data Exchange (ETDEWEB)

    Isaak, D.J.; Bjornn, T.C. (University of Idaho, Idaho Cooperative Fish and Wildlife Research Unit, Moscow, ID)

    1996-03-01

    Northern squawfish Ptychocheilus oregonensis movements were monitored downstream of two lower Snake River dams during the juvenile salmonid migrations of 1992 and 1993. During a high flow year in 1993, the abundance of squawfish in the tailrace of Lower Granite Dam peaked in July, after the majority of juveniles had moved past Lower Granite Dam, and peak abundance was inversely related to river discharge. Few squawfish moved into the tailrace of Ice Harbor Dam in 1993 because of the extended period of spill. Distributions of squawfish in the tailrace of Lower Granite Dam varied between and within years and shifted in response to changing prey densities, flow patterns, water temperature, and diel cycles, but fish consistently used low velocity habitats. Data from Ice Harbor Dam is less extensive, but squawfish distributions there appeared to be affected by changing flow patterns and fish used low velocity habitats. The changes in distribution and abundance of squawfish in tailrace areas are evidence that predation on seaward migrating salmonids depends on the timing of migration and size and timing of runoff. Juvenile salmonids migrating in the spring and early summer will probably be less affected by squawfish predation in tailrace areas than salmon that migrate later in the summer.

  19. Automated screening of microtubule growth dynamics identifies MARK2 as a regulator of leading edge microtubules downstream of Rac1 in migrating cells.

    Directory of Open Access Journals (Sweden)

    Yukako Nishimura

    Full Text Available Polarized microtubule (MT growth in the leading edge is critical to directed cell migration, and is mediated by Rac1 GTPase. To find downstream targets of Rac1 that affect MT assembly dynamics, we performed an RNAi screen of 23 MT binding and regulatory factors and identified RNAi treatments that suppressed changes in MT dynamics induced by constitutively activated Rac1. By analyzing fluorescent EB3 dynamics with automated tracking, we found that RNAi treatments targeting p150(glued, APC2, spastin, EB1, Op18, or MARK2 blocked Rac1-mediated MT growth in lamellipodia. MARK2 was the only protein whose RNAi targeting additionally suppressed Rac1 effects on MT orientation in lamellipodia, and thus became the focus of further study. We show that GFP-MARK2 rescued effects of MARK2 depletion on MT growth lifetime and orientation, and GFP-MARK2 localized in lamellipodia in a Rac1-activity-dependent manner. In a wound-edge motility assay, MARK2-depleted cells failed to polarize their centrosomes or exhibit oriented MT growth in the leading edge, and displayed defects in directional cell migration. Thus, automated image analysis of MT assembly dynamics identified MARK2 as a target regulated downstream of Rac1 that promotes oriented MT growth in the leading edge to mediate directed cell migration.

  20. 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...... and returned to the fjord. The duration of the entire marine migration, from leaving to entering the river, was on average 163 d. The fish returned from the Kattegat Sea to the fjord between 22 July and 21 October. Upon return, the fish spent 1−90 d passing through Randers Fjord, with most individuals...... 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...

  1. Behavior, passage, and downstream migration of juvenile Chinook salmon from Detroit Reservoir to Portland, Oregon, 2014–15

    Science.gov (United States)

    Kock, Tobias J.; Beeman, John W.; Hansen, Amy C.; Hansel, Hal C.; Hansen, Gabriel S.; Hatton, Tyson W.; Kofoot, Eric E.; Sholtis, Matthew D.; Sprando, Jamie M.

    2015-11-16

    An evaluation was conducted to estimate dam passage survival of juvenile Chinook salmon (Oncorhynchus tshawytscha) at Detroit Dam during a period of spill. To estimate dam passage survival, we used a paired-release recapture study design and released groups of tagged fish upstream (997 fish) and downstream (625 fish) of Detroit Dam. A total of 43 fish (6.8 percent) passed Detroit Dam from the upstream release group and passage occurred through regulating outlets (54.8 percent), spill bays (31.0 percent), and turbines (14.3 percent). We do not present dam passage survival estimates from 2014 because these estimates would have been highly uncertain due to the low number of fish that passed Detroit Dam during the study. Secondary objectives were addressed using data collected from tagged fish that were released at the downstream release site.

  2. 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.

  3. Integrated downstream processing of lactoperoxidase from milk whey involving aqueous two-phase extraction and ultrasound-assisted ultrafiltration.

    Science.gov (United States)

    Nandini, K E; Rastogi, Navin K

    2011-01-01

    The present work involves the adoption of an integrated approach for the purification of lactoperoxidase from milk whey by coupling aqueous two-phase extraction (ATPE) with ultrasound-assisted ultrafiltration. The effect of system parameters of ATPE such as type of phase system, polyethylene glycol (PEG) molecular mass, system pH, tie line length and phase volume ratio was evaluated so as to obtain differential partitioning of contaminant proteins and lactoperoxidase in top and bottom phases, respectively. PEG 6000-potassium phosphate system was found to be suitable for the maximum activity recovery of lactoperoxidase 150.70% leading to 2.31-fold purity. Further, concentration and purification of enzyme was attempted using ultrafiltration. The activity recovery and purification factor achieved after ultrafiltration were 149.85% and 3.53-fold, respectively. To optimise productivity and cost-effectiveness of integrated process, influence of ultrasound for the enhancement of permeate flux during ultrafiltration was also investigated. Intermittent use of ultrasound along with stirring (2 min acoustic and 2 min stirring) resulted in increased permeate flux from 0.94 to 2.18 l/m(2) h in comparison to the ultrafiltration without ultrasound. The use of ultrasound during ultrafiltration resulted in increase in flux, but there was no significant change in activity recovery and purification factor. The integrated approach involving ATPE and ultrafiltration may prove to be a feasible method for the downstream processing of lactoperoxidase from milk whey.

  4. Effect of waterborne exposure to 4-tert-octylphenol and 17beta-estradiol on smoltification and downstream migration in Atlantic salmon, Salmo salar.

    Science.gov (United States)

    Bangsgaard, Karsten; Madsen, Steffen S; Korsgaard, Bodil

    2006-10-25

    Groups of Atlantic salmon parr (November, Exp. 1) or pre-smolts (March, Exp. 2) were exposed to estradiol-17beta (E2 conc.: nominal 500 ngl(-1)/actual 8-16 ngl(-1)) and two doses of tert-octylphenol (OP: nominal 25 microgl(-1)/actual 4.5-6.5 microgl(-1) and OP: nominal 100 microgl(-1)/actual 10-30 microgl(-1)) for 26 days in fresh water, and the effects on physiological and behavioural aspects of parr-smolt transformation were investigated. Vitellogenesis was induced by all treatments, as indicated by elevated levels of plasma vitellogenin (Vtg) and hepatosomatic index. Elevated Vtg levels were still found in OP-100 and E2-treated fish 4-5 months after cessation of treatment, indicating a slow clearance of Vtg from circulation. Smolting was compromised by E2 and OP-100 treatment as judged by reduced gill Na(+), K(+)-ATPase activity and impaired ability to regulate plasma osmolality and muscle water content in 24-h sea water (SW) challenge tests during the period of smolting. Downstream migratory behaviour was monitored from late April to July (Exp. 2) by implanting passive integrated transponder tags into subgroups of treated and control smolts and placing them in a stream raceway. Irrespective of treatment, nocturnal downstream movement was initiated in all groups on April 23, switching to diurnal movement in late May. Average swimming speed was estimated to be higher than current speed, indicating active migration. E2 and OP-100 fish migrated at lower frequency than control fish, suggesting a reduced migratory drive. The data suggests that waterborne exposure of salmon to xenoestrogens reduce both physiological and behavioural components of smoltification, even when exposure occurs several months prior to smolting.

  5. Leader cells regulate collective cell migration via Rac activation in the downstream signaling of integrin beta 1 and PI3K

    OpenAIRE

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

    2015-01-01

    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 f...

  6. Migration

    NARCIS (Netherlands)

    Gienapp, P.; Candolin, Ulrika; Wong, Bob

    2012-01-01

    This chapter examines how human-induced environmental changes affect migration. It explores how such changes affect conditions along the migration route, as well as the cues that are used in the timing of migration such as the celestial bodies and the planet's magnetic field. It emphasizes the effec

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

    Directory of Open Access Journals (Sweden)

    Bridget S Green

    Full Text Available BACKGROUND: 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. METHODOLOGY AND PRINCIPAL FINDINGS: 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. CONCLUSIONS AND SIGNIFICANCE: 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.

  8. 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.

  9. Whitebark pine (Pinus albicaulis) assisted migration potential: testing establishment north of the species range.

    Science.gov (United States)

    McLane, Sierra C; Aitken, Sally N

    2012-01-01

    The translocation of species into habitable locations outside of their current ranges, termed assisted migration, has been proposed as a means of saving vulnerable species from extinction as a result of climate change. We explore the use of this controversial technique using a threatened keystone species in western North America, whitebark pine (Pinus albicaulis), as a case study. Species distribution models predict that whitebark pine will be extirpated from most of its current range as temperatures rise over the next 70 years. However, the same models indicate that a large area within northwestern British Columbia, Canada, is climatically suitable for the species under current conditions and will remain so throughout the 21st century. To test the capacity of whitebark pine to establish relative to climatic and habitat features within its predicted climatic range, we planted seeds from seven populations in eight locations spanning from 600 km southeast to 800 km northwest of the northern boundary of the current species range. During the first three growing seasons, germination occurred in all locations. Nearly three times as many treated (induced maturation and broken dormancy) than untreated seeds germinated, and most treated seeds germinated a year earlier than the untreated seeds. Germination, survival, and growth were primarily influenced by seed mass, site climate conditions related to the duration of snow cover, and provenance temperature. Our experiment provides a preliminary test of models predicting the existence of climatically suitable whitebark pine habitat north of the current species ranges. More broadly, our techniques and results inform the development of scientific guidelines for assisting the migration of other species that are highly threatened by climate change. Applied case studies of this kind are critical for assessing the utility of species distribution models as conservation planning tools.

  10. Assessment of pulsed DC electric field to guide downstream migrating sea lamprey in experimental flume at USGS Conte Anadromous Fish Lab, Turners Falls, MA (December 2013)

    Science.gov (United States)

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

    2017-01-01

    This is a tabular data set that contains records of water velocity, depth, temperature and trial information such as start and stop times and date for experimental trials testing the effect of an electric field on the movement patterns and distribution of juvenile sea lamprey moving downstream in an experimental flume. Distribution is recorded for each individual lamprey as presence (1) or absence (0) in a series of downstream collection nets positions laterally across the flume. The data is formatted as comma delimited and contains no special characters. The trails were conducted during December 2 through December 15, 2013 in a 6 meter wide experimental flume at the Conte Anadromous Fish Research Lab in Turners Falls, MA.

  11. 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.

  12. Alpine biodiversity and assisted migration: The case of the American pika (Ochotona princeps)

    Science.gov (United States)

    Wilkening, Jennifer L.; Ray, Chris; Ramsay, Nathan G.; Klingler, Kelly

    2015-01-01

    Alpine mammals are predicted to be among the species most threatened by climate change, due to the projected loss and further fragmentation of alpine habitats. As temperature or precipitation regimes change, alpine mammals may also be faced with insurmountable barriers to dispersal. The slow rate or inability to adjust to rapidly shifting environmental conditions may cause isolated alpine species to become locally extirpated, resulting in reduced biodiversity. One proposed method for mitigating the impacts of alpine species loss is assisted migration. This method, which involves translocating a species to an area with more favourable climate and habitat characteristics, has become the subject of debate and controversy in the conservation community. The uncertainty associated with climate change projections, coupled with the thermal sensitivity of many alpine mammals, makes it difficult to a priori assess the efficacy of this technique as a conservation management tool. Here we present the American pika (Ochotona princeps) as a case study. American pikas inhabit rocky areas throughout the western US, and populations in some mountainous areas have become locally extirpated in recent years. We review known climatic and habitat requirements for this species, and also propose protocols designed to reliably identify favourable relocation areas. We present data related to the physiological constraints of this species and outline specific requirements which must be addressed for translocation of viable populations, including wildlife disease and genetic considerations. Finally, we discuss potential impacts on other alpine species and alpine communities, and overall implications for conserving alpine biodiversity in a changing climate.

  13. 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.

  14. Considering extinction of dependent species during translocation, ex situ conservation, and assisted migration of threatened hosts.

    Science.gov (United States)

    Moir, Melinda L; Vesk, Peter A; Brennan, Karl E C; Poulin, Robert; Hughes, Lesley; Keith, David A; McCarthy, Michael A; Coates, David J

    2012-04-01

    Translocation, introduction, reintroduction, and assisted migrations are species conservation strategies that are attracting increasing attention, especially in the face of climate change. However, preventing the extinction of the suite of dependent species whose host species are threatened is seldom considered, and the effects on dependent species of moving threatened hosts are unclear. There is no published guidance on how to decide whether to move species, given this uncertainty. We examined the dependent-host system of 4 disparate taxonomic groups: insects on the feather-leaf banksia (Banksia brownii), montane banksia (B. montana), and Stirling Range beard heath (Leucopogon gnaphalioides); parasites of wild cats; mites and ticks on Duvaucel's gecko (Hoplodactylus duvaucelii) and tuatara (Sphenodon punctatus); and internal coccidian parasites of Cirl Bunting (Emberiza cirlus) and Hihi (Notiomystis cincta). We used these case studies to demonstrate a simple process for use in species- and community-level assessments of efforts to conserve dependents with their hosts. The insects dependent on Stirling Range beard heath and parasites on tigers (Panthera tigris) appeared to represent assemblages that would not be conserved by ex situ host conservation. In contrast, for the cases of dependent species we examined involving a single dependent species (internal parasites of birds and the mite Geckobia naultina on Duvaucel's gecko), ex situ conservation of the host species would also conserve the dependent species. However, moving dependent species with their hosts may be insufficient to maintain viable populations of the dependent species, and additional conservation strategies such as supplementing populations may be needed.

  15. 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.

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

    Science.gov (United States)

    Medina, Manuela; Rémy, Murielle; Thébaud, Noélie Brunehilde; Bareille, Reine; Chassande, Olivier; Amédée, Joëlle; Catros, Sylvain

    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. PMID:27833916

  17. High Altitude Bird Migration at Temperate Latitudes: A Synoptic Perspective on Wind Assistance

    NARCIS (Netherlands)

    Dokter, A.M.; Shamoun-Baranes, J.; Kemp, M.U.; Tijm, S.; Holleman, I.

    2013-01-01

    At temperate latitudes the synoptic patterns of bird migration are strongly structured by the presence of cyclones and anticyclones, both in the horizontal and altitudinal dimensions. In certain synoptic conditions, birds may efficiently cross regions with opposing surface wind by choosing a higher

  18. Labour migration of Polish nurses: a questionnaire survey conducted with the Computer Assisted Web Interview technique

    OpenAIRE

    2016-01-01

    Background According to data from the Organisation for Economic Cooperation and Development, Poland has one of the lowest numbers of nurses (5.2) per 1000 inhabitants among 28 EU countries. The migration of nurses from Poland has particular importance in the context of scarce human resources in this professional group, especially given the increasingly ageing population in European societies, which will entail an increased demand for nursing and care services. The aim of the study was to obta...

  19. High Altitude Bird Migration at Temperate Latitudes: A Synoptic Perspective on Wind Assistance

    OpenAIRE

    2013-01-01

    At temperate latitudes the synoptic patterns of bird migration are strongly structured by the presence of cyclones and anticyclones, both in the horizontal and altitudinal dimensions. In certain synoptic conditions, birds may efficiently cross regions with opposing surface wind by choosing a higher flight altitude with more favourable wind. We observed migratory passerines at mid-latitudes that selected high altitude wind optima on particular nights, leading to the formation of structured mig...

  20. Return migration in the context of parental assistance in the AIDS epidemic: the Thai experience.

    Science.gov (United States)

    Knodel, John; VanLandingham, Mark

    2003-07-01

    Most persons with AIDS (PWAs) eventually require demanding caregiving. This can prompt changes in living arrangements during the course of the illness. Few studies have attempted to examine the potential links between AIDS and migration from this perspective. The present study uses both direct and indirect approaches to examine the extent of return migration of adults with AIDS in Thailand and explores how this is linked to residence with and care by older aged parents. Methodological challenges and various approaches to the study of this phenomenon are discussed. Despite differences in the nature of information available from our samples and in basic sample characteristics, the findings show a consistent pattern suggestive of extensive return migration among PWAs. The fact that most return migrants die within a few months of their return indicates that they are seeking parental caregiving during the final stages of the illness. The vast majority of PWAs who returned home after becoming ill did so because of their illness, particularly due to a need for care.

  1. Coil migrating out of a small wide-necked aneurysm embolized with stent-assisted technique

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Stent-assisted coiling is one of the techniques used to treat intracranial aneurysms with wide necks or unfavorable neck-to-fundus ratios, which have been traditionally considered as poor candidates for Guglielmi detachable coil ( GDC ) embolization owing to the significant risk of coil herniation into the parent artery[1-5]. With this technique, fusiform, wide-necked and geometrically difficult aneurysms as well as pseudoaneurysms have been successfully treated with different follow-up results. Herein, we present an aneurysm case with a coil escaping from the confinement of the stent.

  2. 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

  3. Effect of waterborne exposure to 4-tert-octylphenol and 17beta-estradiol on smoltification and downstream migration in Atlantic salmon, Salmo salar

    DEFF Research Database (Denmark)

    Bangsgaard, Karsten; Madsen, Steffen S; Korsgaard, Bodil

    2006-01-01

    -treated fish 4-5 months after cessation of treatment, indicating a slow clearance of Vtg from circulation. Smolting was compromised by E2 and OP-100 treatment as judged by reduced gill Na+, K+-ATPase activity and impaired ability to regulate plasma osmolality and muscle water content in 24-h sea water (SW...... movement was initiated in all groups on April 23, switching to diurnal movement in late May. Average swimming speed was estimated to be higher than current speed, indicating active migration. E2 and OP-100 fish migrated at lower frequency than control fish, suggesting a reduced migratory drive. The data...

  4. Early establishment response of different Pinus nigra ssp. salzmanii seed sources on contrasting environments: Implications for future reforestation programs and assisted population migration.

    Science.gov (United States)

    Taïbi, K; del Campo, A D; Aguado, A; Mulet, J M

    2016-04-15

    Forest restoration constitutes an important issue within adaptive environmental management for climate change at global scale. However, effective implementation of these programs can only be achieved by revising current seed transfer guidelines, as they lack inherent spatial and temporal dynamics associated with climate change. In this sense, provenance trials may provide key information on the relative performance of different populations and/or genotypes under changing ecological conditions. This study addresses a methodological approach to evaluate early plantation performance and the consequent phenotypic plasticity and the pattern of the adaptation of different seed sources in contrasting environments. To this end, six seed sources of Salzmann pine were tested at three contrasting trial sites testing a hypothetical assisted population migration. Adaptation at each site was assessed through Joint Regression and Additive Main effect and Multiplication Interaction (AMMI) models. Most of the observed variation was attributed to the environment (above 90% for all traits), even so genotype and genotype by environment interaction (GxE) were significant. Seedlings out-planted under better site conditions did not differ in survival but in height growth. However, on sites with higher constraints, survival differed among seed sources and diameter growth was high. The adaptation analyses (AMMI) indicated that the cold-continental seed source 'Soria' performed as a generalist seed source, whereas 'Cordilleras Béticas', the southernmost seed source, was more adapted to harsh environments (frost and drought) in terms of survival. The results supported partially the hypothesis that assisted migration of seed sources makes sense within limited transfer distances, and this was reinforced by the GxE results. The present study could be valuable to address adaptive transfer of seedings in ecological restoration and to determine the suitable seed sources for reforestation programs

  5. Improved bone regeneration and root coverage using a resorbable membrane with physically assisted cell migration and DFDBA.

    Science.gov (United States)

    Dodge, J R; Greenwell, H; Drisko, C; Wittwer, J W; Yancey, J; Rebitski, G

    2000-08-01

    Twelve patients with 2 Miller Class I or II buccal recession defects measuring > or = 3.0 mm were treated using the principles of guided tissue regeneration and followed for 12 months. The effectiveness of a polylactide (Guidor) resorbable membrane (GA sites) was compared to a combination treatment of polylactide membrane plus polyglactin root-lining mesh (Vicryl) and demineralized freeze-dried bone allograft (DFDBA) (GVB sites) designed to enhance cell migration and bone regeneration. There was 90% mean soft tissue root coverage for the GVB sites and 78% for the GA sites. The mean osseous dehiscence area coverage with hard tissue was 75% for GVB sites and 30% for GA sites.

  6. Fluxos migratórios de mulheres para o trabalho reprodutivo: a globalização da assistência Migratory flows of women for reproductive work: the globalization of assistance

    Directory of Open Access Journals (Sweden)

    Teresa Kleba Lisboa

    2007-12-01

    Full Text Available A partir de uma experiência vivenciada como integrante do grupo que trabalhou a temática da migração de mulheres na Internationale Frauen Universität (IFU em 2000, apresento neste artigo uma discussão sobre os fluxos migratórios de mulheres que deixam os países periféricos movendo-se em direção aos países de Primeiro Mundo para trabalhar como empregadas domésticas. Ocorre nesse processo uma verdadeira globalização da assistência, formando-se inclusive cadeias entre mulheres de diferentes nações, classes e etnias. As principais causas das migrações estão ligadas à luta pela sobrevivência, oportunidade de trabalho e estudo e conquista da independência em relação à opressão e à violência. Como proposta final, sugiro que, para conter os fluxos migratórios, são necessárias políticas públicas que venham ao encontro das necessidades básicas das mulheres em seus países de origem.Based on an experience as a member of the group that worked with the theme of migration of women at the Internationale Frauen Universität (IFU in 2000, this article presents a discussion about the migratory flows of women who work as domestic servants. There is a true globalization of assistance in this process, which even establishes chains between women of different nations, classes and ethnicities. The main causes of the migrations are linked to the struggle for survival and the opportunity to work, study and achieve independence from violence and oppression. I propose that, to contain migratory flows, public policies that meet the basic needs of the women in their countries of origin are necessary.

  7. The restructuring of Shell Downstream; La restructuration de Shell Downstream

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, F.

    2005-01-15

    To facing a more and more competitive environment, the Group Shell began a restructuring. While the group was organized on horizontal national lines, it is creating today an integrated downstream activity. The word of this restructuring is profit. (A.L.B.)

  8. Preliminary screening of downstream proteins of Sox2 and role of Sox2 in colonic cancer cell migration and invasion%Sox2下游调控蛋白的筛选及其对大肠癌细胞增殖、迁移的影响

    Institute of Scientific and Technical Information of China (English)

    周敏; 陆滟霞; 袁理; 郑林; 刘燕; 洪敏; 张超; 李学农

    2014-01-01

    Objective To screen the down-stream proteins of transcription factor Sox2 and explore the role of Sox2 in the proliferation and migration of colonic cancer cells in vitro. Methods The cellular proteins were separated by SDS-PAGE electrophoresis and stained with Coomassie blue and amine plated silver. The differentially expressed proteins was identified by mass spectrometry and verified by QPCR and Western blotting. A cell counting kit-8 (CCK8) assay was performed to evaluate the cell proliferation, and the cell migration was assessed using Transwell assay. Results S3a was identified by proteomics technology as a Sox2-downregulated protein while ENO1 and gama-actin the up-regulated proteins. QPCR and Western blotting analyses showed that overexpression of Sox2 significantly decreased the expression of S3a (P<0.005) and increased the expression of ENO1(P<0.05), but had no significant effect on gama-actin expression. Sox2 overexpression obviously promoted cell proliferation and migration (P<0.05), while inhibition of Sox2 produced contrary effects (P<0.05). Conclusion Sox2 negatively regulates S3a expression and positively regulates ENO1 expression to promot the proliferation and migration of colonic cancer cells.%目的:分析大肠癌细胞转录因子Sox2对大肠癌细胞增殖及迁移的影响。方法应用SDS-PAGE蛋白电泳,结合考马斯亮蓝及镀胺银染色方法,筛选差异蛋白。质谱分析筛选Sox2下游调控蛋白,应用定量PCR(QPCR)及Western blotting验证和鉴定下游调控蛋白。Cell Counting Kit-8(CCK8)观察Sox2对大肠癌细胞增殖的影响,Transwell实验观察Sox2对迁移能力的影响。结果应用蛋白组学技术成功筛选出Sox2下调蛋白S3a、上调蛋白ENO1、Gama-actin。QPCR和Western blotting显示,Sox2过表达后,大肠癌细胞S3a表达减少(P<0.005),ENO1表达增加(P<0.05),Gama-actin表达无明显差异,细胞增殖及迁移能力提高(P<0.05);Sox2

  9. microRNA-181b promotes migration and invasion of osteosarcoma cells by targeting N-myc downstream regulated gene 2%miR-181b通过靶向调控N-myc下游调节基因2影响骨肉瘤细胞的迁移和侵袭

    Institute of Scientific and Technical Information of China (English)

    邵建立; 李志忠; 王亮; 焦根龙; 周志刚; 孙国栋

    2016-01-01

    Objective To investigate the effects of miR-181b on the migration and invasion of osteosarcoma cells. Methods Three cultured osteosarcoma cell lines and MG-63 cells transfected with miR-181b inhibitor were examined for miR-181b expression using qRT-PCR analysis. The cell migration and invasion of the transfected cells were assessed with Transwell assay. The targets of miR-181b were predicted using a miRNA target prediction software and the results were verified with luciferase reporter assay. The target protein expression in osteosarcoma cells lines was determined by Western blotting, and the cell migration and invasion changes following inhibition of miR-181b or its target protein were assessed using Transwell assay. Results All the 3 osteosarcoma cells lines showed significantly up-regulated miR-181b expression. Inhibition of miR-181b expression obviously suppressed the migration and invasion of MG-63 cells. Based on luciferase reporter assay, N-myc downstream regulated gene 2 (NDRG2) was identified as the direct target gene of miR-181b, and inhibition of NDRG2 expression significantly reversed the effect of miR-181b on cell migration and invasion in MG-63 cells. Conclusion miR-181b is over-expressed in osteosarcoma cells, and inhibition of miR-181b, which directly targets NDRG2, can suppress the migration and invasion of osteosarcoma cells.%目的:探讨miR-181b对骨肉瘤细胞迁移和侵袭的影响。方法培养骨肉瘤细胞,实时荧光定量PCR检测miR-181b在骨肉瘤细胞中的表达。抑制miR-181b的表达,Transwell检测对骨肉瘤迁移和侵袭的影响;生物信息学分析miR-181b靶基因并采用荧光素酶报告基因分析miR-181b和靶基因在骨肉瘤中是否直接作用,同时采用Western Blotting检测靶基因在骨肉瘤细胞中的表达以及Transwell检测靶基因对骨肉瘤迁移和侵袭的影响。结果实时荧光定量PCR结果表明miR-181b在骨肉瘤细胞中高表达。抑制miR-181b的表达

  10. 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.

  11. 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)

  12. Return migration.

    Science.gov (United States)

    Gmelch, G

    1980-01-01

    The author reviews the findings of the growing literature on return migration. Topics covered include typologies of return migrants, reasons for return, adaptation and readjustment of returnees, and the impact of return migration on the migrants' home societies. The focus of the study is on international return migration, migration to Northern Europe and northeastern North America, and return migration to the southern and eastern fringes of Europe and the Caribbean

  13. Central administration of growth hormone-releasing hormone triggers downstream movement and schooling behavior of chum salmon (Oncorhynchus keta) fry in an artificial stream.

    Science.gov (United States)

    Ojima, Daisuke; Iwata, Munehico

    2009-03-01

    Anadromous salmonids migrate downstream to the ocean (downstream migration). The neuroendocrine mechanism of triggering the onset of downstream migration is not well known. We investigated the effects of 14 chemicals, including neuropeptides, pineal hormones, neurotransmitters, and neuromodulators (growth hormone-releasing hormone: GHRH, thyrotropin-releasing hormone, corticotropin-releasing hormone: CRH, gonadotropin-releasing hormone, melatonin, N-acetyl serotonin, serotonin, beta-endorphin, enkephalin, dopamine, norepinephrine, epinephrine, acetylcholine, and histamine) on the onset of downstream migration in chum salmon (Oncorhynchus keta) fry. We defined downstream migration as a downstream movement (negative rheotaxis) with schooling behavior and counted the number of downstream movements and school size in experimental circulation tanks. An intracerebroventricular injection of GHRH, CRH, melatonin, N-acetyl serotonin, or serotonin stimulated the number of downstream movements. However, GHRH was the only chemical that also stimulated an increase in schooling behavior. These results suggest that CRH, melatonin, N-acetyl serotonin, and serotonin are involved in the stimulation of downstream movement in chum salmon, while GHRH stimulates both downstream movement and schooling behavior.

  14. CNOOC Advancing into Downstream of Petroleum Industry

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    @@ "China National Offshore Oil Corporation is starting to expand its business into the downstream sector after making achievements continuously in exploration and development," Wang Yan, president of the corporation,told reporter in an interview, adding that the downstream sector is the third development stage for China National Offshore Oil Corporation (CNOOC).

  15. 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.

  16. [Internal migration].

    Science.gov (United States)

    Borisovna, L

    1991-06-01

    Very few studies have been conducted that truly permit explanation of internal migration and it repercussions on social and economic structure. It is clear however that a profound knowledge of the determinants and consequences of internal migration will be required as a basis for economic policy decisions that advance the goal of improving the level of living of the population. the basic supposition of most studies of the relationship of population and development is that socioeconomic development conditions demographic dynamics. The process of development in Mexico, which can be characterized by great heterogeneity, consequently produces great regional disparities. At the national level various studies have estimated the volume of internal migration in Mexico, but they have usually been limited to interstate migration because the main source of data, the census, is classified by states. But given the great heterogeneity within states in all the elements related to internal migration, it is clear that studies of internal migration within states are also needed. Such studies are almost nonexistent because of their technical difficulty. National level studies show that interstate migration increased significantly between 1940-80. The proportion of Mexicans living outside their states of birth increased by 558% in those years, compared to the 342% increase in the total Mexican population. Although Puebla has a high rate of increase, migration has kept it below Mexico's national growth rate. Migration between Puebla and other states and within Puebla has led to an increasing unevenness of spatial distribution. Between 1970-80, 57 of Puebla's municipios had growth rates above the state average of 2.8%/year, 6 had growth rates equal to the average, and 129 had growth rates that were below the average but not negative. 25 states with negative growth rates that were considered strongly expulsive. In 1980, 51.7% of the population was concentrated in the 57 municipios

  17. Downstream bioprocess characterisation within microfluidic devices

    DEFF Research Database (Denmark)

    Marques, Marco; Krühne, Ulrich; Szita, Nicolas

    2016-01-01

    Miniaturising bioprocess unit operation steps is a well-established approach to find novel routes for process intensification and improved process economics. While a number of microbioreactors have been presented over the last 15 years, miniaturised downstream unit operations (mDUO) are less deve...

  18. MITIGATION OF SEDIMENTATION HAZARDS DOWNSTREAM FROM RESERVOIRS

    Institute of Scientific and Technical Information of China (English)

    Ellen WOHL; Sara RATHBURN

    2003-01-01

    Many reservoirs currently in operation trap most or all of the sediment entering the reservoir,creating sediment-depleted conditions downstream. This may cause channel adjustment in the form of bank erosion, bed erosion, substrate coarsening, and channel planform change. Channel adjustment may also result from episodic sediment releases during reservoir operation, or from sediment evacuation following dam removal. Channel adjustment to increased sediment influx depends on the magnitude, frequency, duration and grain-size distribution of the sediment releases, and on the downstream channel characteristics. Channel adjustment may occur as a change in substrate sizedistribution, filling of pools, general bed aggradation, lateral instability, change in channel planform,and/or floodplain aggradation. The increased sediment availability may alter aquatic and riparian habitat, reduce water quality, distribute adsorbed contaminants along the river corridor, and provide germination sites for exotic vegetation. Mitigation of these sedimentation hazards requires: (1)mapping grain-size distribution within the reservoir and estimating the grain-size distributions of sediment that will be mobilized through time; (2) mapping shear stress and sediment transport capacity as a function of discharge on the basis of channel units for the length of the river likely to be affected; (3) mapping potential depositional zones, and aquatic habitat and "acceptable losses," along the downstream channel, and comparing these volumes to the total sediment volume stored in the reservoir as a means of estimating total transport capacity required to mobilize reservoir sediment delivered to the channel; (4) designing discharge and sediment release regime (magnitude, frequency,duration) to minimize adverse downstream impacts; and (5) developing plans to remove, treat, contain,or track contaminants, and to restrict establishment of exotic vegetation. The North Fork Poudre River in Colorado is used to

  19. 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.

  20. Fish reproductive guilds downstream of dams.

    Science.gov (United States)

    Vasconcelos, L P; Alves, D C; Gomes, L C

    2014-11-01

    Fish reproductive guilds were used to evaluate the responses of species with different reproductive strategies during two different periods of post-dam construction. The data used for the comparisons were collected in the upper Paraná River floodplain (Brazil), downstream of the Porto Primavera dam, 2 and 10 years after impoundment. The abundance (catch per unit effort, CPUE), species richness, evenness and structure of communities, all within reproductive guilds, were used to test the hypothesis that these metrics vary spatially and temporally. The influence of damming on species structure and the diversity of fish reproductive guilds varied spatiotemporally, and species with opportunistic reproductive strategies tended to be less affected. Conversely, long-distance migratory species responded more markedly to spatiotemporal variations, indicating that the ecosystem dynamics exert greater effects on populations of these species. Thus, the effects of a dam, even if attenuated, may extend over several years, especially downstream. This finding emphasizes the importance of maintaining large undammed tributaries downstream of reservoirs.

  1. 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...

  2. Upstream and Downstream Influence in STBLI Instability

    Science.gov (United States)

    Martin, Pino; Priebe, Stephan; Helm, Clara

    2016-11-01

    Priebe and Martín (JFM, 2012) show that the low-frequency unsteadiness in shockwave and turbulent boundary layer interactions (STBLI) is governed by an inviscid instability. Priebe, Tu, Martín and Rowley (JFM, 2016) show that the instability is an inviscid centrifugal one, i.e Görtlerlike vortices. Previous works had given differing conclusions as to whether the low-frequency unsteadiness in STBLI is caused by an upstream or downstream mechanism. In this paper, we reconcile these opposite views and show that upstream and downstream correlations co-exist in the context of the nature of Görtler vortices. We find that the instability is similar to that in separated subsonic and laminar flows. Since the turbulence is modulated but passive to the global mode, the turbulent separated flows are amenable to linear global analysis. As such, the characteristic length and time scales, and the receptivity of the global mode might be determined, and low-order models that represent the low-frequency dynamics in STBLI might be developed. The centrifugal instability persists even under hypersonic conditions. This work is funded by the AFOSR Grant Number AF9550-15-1-0284 with Dr. Ivett Leyva.

  3. A Copernicus downstream service for surface displacement monitoring in Germany

    Science.gov (United States)

    Cahyadi Kalia, Andre; Frei, Michaela; Lege, Thomas

    2016-04-01

    SAR Interferometry is a powerful technique able to detect and monitor various surface displacements caused by e.g. gravitative mass movement, subrosion, groundwater extraction, fluid injection, natural gas extraction. These processes can e.g. cause damage to buildings, infrastructure, affect ecosystems, agriculture and the economic use of the geological underground by influencing the hydro(geo)logical setting. Advanced techniques of interferometric processing (Persistent Scatterer Interferometry, PSI) allow highly precise displacement measurements (mm precision) by analyzing stacks of SAR imagery. The PSI mapping coverage can be increased to entire nations by using several adjacent satellite tracks. In order to assist the operational use of this technique a German-wide, officially approved, PSI dataset is under development. The intention of this presentation is to show i) the concept of the Copernicus downstream service for surface displacement monitoring in Germany and ii) a pilot study to exemplarily demonstrate the workflow and potential products from the Copernicus downstream service. The pilot study is focusing on the built up of an officially approved wide-area PSI dataset. The study area covers an area of more than 30.000 km² and is located in the Northwest German Basin. Several natural processes (e.g. compaction of marine sediments, peat loss) and anthropogenic activities (e.g. natural gas extraction, rock salt mining) are causing surface displacements in the study area. The PSI analysis is based on six ERS-1/-2 data stacks covering the timespan from 1992 until 2001. Each data stack consists of 49 to 73 ERS-1/-2 SAR images. A comparison of the PSI results with thematic data (e.g. volume and location of extracted natural gas) strongly indicates that a part of the detected land subsidence is caused by natural gas extraction. Furthermore, land subsidence caused by e.g. fluid injection and rock salt mining were successfully detected by the PSI analysis.

  4. EU Migration Policy

    OpenAIRE

    Kleinschmidt, Harald

    2004-01-01

    I shall confine myself in this paper to international migration as migration across international borders.I do so despite the fact that,still today,international migration accounts only for a small share of migration at large.Likewise,I shall deal widh voluntary migration and shall thus exclude,deportation ...

  5. Downstream Thermal Evolution of Vortex Cores

    Science.gov (United States)

    Gómez-Barea, A.; Herrada, M. A.; Pérez-Saborid, M.; Barrero, A.

    1999-11-01

    The downstream evolution of the total temperature field in a quasi-incompressible axisymmetric vortex core has been computed. Starting at an initial station (z=0) with velocity profiles of the Burgers type and given temperature distributions, the numerical results of the evolution show that, according to experimental results, the total temperature in the near-axis region decreases substantially due to the work done by pressure and viscous forces together with the effect of both convection and conduction of heat. Depending on the values of the parameters characterizing the initial profiles and on the value of the Prandtl number, the vortex either breaks down or eventually reaches a self-similar regime. The results obtained shed light on the basic physics involved in the thermal separation phenomenon which appears inside Ranque-Hilsch vortex tubes.

  6. Channel changes downstream from a dam

    Science.gov (United States)

    Hadley, R.F.; Emmett, W.W.

    1998-01-01

    A flood-control dam was completed during 1979 on Bear Creek, a small tributary stream to the South Platte River in the Denver, Colorado, area. Before and after dam closure, repetitive surveys between 1977 and 1992 at five cross sections downstream of the dam documented changes in channel morphology. During this 15-year period, channel width increased slightly, but channel depth increased by more than 40 percent. Within the study reach, stream gradient decreased and median bed material sizes coarsened from sand in the pools and fine gravel on the riffle to a median coarse gravel throughout the reach. The most striking visual change was from a sparse growth of streamside grasses to a dense growth of riparian woody vegetation.

  7. Ammonia downstream from HH 80 North

    Science.gov (United States)

    Girart, Jose M.; Rodriguez, Luis F.; Anglada, Guillem; Estalella, Robert; Torrelles, Jose, M.; Marti, Josep; Pena, Miriam; Ayala, Sandra; Curiel, Salvador; Noriega-Crespo, Alberto

    1994-01-01

    HH 80-81 are two optically visible Herbig-Haro (HH) objects located about 5 minutes south of their exciting source IRAS 18162-2048. Displaced symmetrically to the north of this luminous IRAS source, a possible HH counterpart was recently detected as a radio continuum source with the very large array (VLA). This radio source, HH 80 North, has been proposed to be a member of the Herbig-Haro class since its centimeter flux density, angular size, spectral index, and morphology are all similar to those of HH 80. However, no object has been detected at optical wavelengths at the position of HH 80 North, possibly because of high extinction, and the confirmation of the radio continuum source as an HH object has not been possible. In the prototypical Herbig-Haro objects HH 1 and 2, ammonia emission has been detected downstream of the flow in both objects. This detection has been intepreted as a result of an enhancement in the ammonia emission produced by the radiation field of the shock associated with the HH object. In this Letter we report the detection of the (1,1) and (2,2) inversion transitions of ammonia downstream HH 80 North. This detection gives strong suppport to the interpretation of HH 80 North as a heavily obscured HH object. In addition, we suggest that ammonia emission may be a tracer of embedded Herbig-Haro objects in other regions of star formation. A 60 micrometer IRAS source could be associated with HH 80 North and with the ammonia condensation. A tentative explanation for the far-infrared emission as arising in dust heated by their optical and UV radiation of the HH object is presented.

  8. Research on Protocol Migration

    Institute of Scientific and Technical Information of China (English)

    汪芸; 顾冠群; 等

    1996-01-01

    This paper elaborates the concept and model of protocol migration in network interconnection.Migration strategies and principles are discussed and several cases are studied in detail which show the basic procedure and techniques used in protocol migration.

  9. Migration of birds

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report covers the migration of birds. Topics covered include why birds migrate, when birds migrate, speed, altitude, courses, distance, major flyways and...

  10. Internationalization and migration pressure.

    Science.gov (United States)

    Kultalahti, O

    1994-01-01

    The author first develops the concept of migration pressure, which is defined as the growth in the number of people wishing to migrate and the barriers preventing them from so doing. Both macro- and micro-level factors affecting migration pressure are identified. Historical trends in migration pressure in Finland are then discussed. The author then applies this concept to the analysis of current Finnish migration trends. The primary focus is on international migration.

  11. Investigating the phenology of seaward migration of juvenile brown trout (Salmo trutta) in two European populations

    DEFF Research Database (Denmark)

    Winter, E R.; Tummers, J. S.; Aarestrup, Kim;

    2016-01-01

    Recent evidence supports the existence of a downstream autumn-migratory phenotype in juvenile anadromous brown trout (Salmo trutta), however the precise timing, extent and ecological significance of such behaviour remains ambiguous. We investigated the phenology of downstream migration of wild...

  12. Microbial production of scleroglucan and downstream processing

    Science.gov (United States)

    Castillo, Natalia A.; Valdez, Alejandra L.; Fariña, Julia I.

    2015-01-01

    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 β-1,3-β-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 exopolysaccharide 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. PMID:26528259

  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. DOWNSTREAM ECOCIDE FROM UPSTREAM WATER PIRACY

    Directory of Open Access Journals (Sweden)

    Miah Muhammad Adel

    2012-01-01

    Full Text Available 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 Bangladesh’s northwest upon the Ganges River, puts Bangladesh’s 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 upstream on the Barak River on the northeast of Bangladesh. Furthermore, India has chalked out a grand plan for river networking. Exploration has been made to assess the degree of the ecosystem degradation both inland and on the coast due to all water diversion constructions around the border, except for the Tipaimukh Dam in which case estimation of projected ecosystem degradation has been mentioned. Finally, Indian grand plan of river networking plan has been briefly touched upon. Site visitations, observations, surveys, measurements and interviews of professionals were made in the project country. Relevant literatures on this issue were reviewed in electronic and print databases. Related published articles in electronic and print media were systematically searched following the key words for the case. Finally, both electronic and print news media have been closely followed to know the latest developments on this issue. The reduced flow of the Ganges in Bangladesh has caused scarcity of fresh water, species endangerment and extinction, obstruction to livestock raising, loss of livelihoods, people’s displacement, changes in crop production, reduction in navigable routes, extreme weather, increased flood occurrences, scarcity of potable water, groundwater contamination, reduction in coastal sediment deposition, deterioration of the Ganges water quality and inland intrusion of saline water front. Water diversion constructions in other rivers have

  15. 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.

  16. Fertility, Migration, and Altruism

    OpenAIRE

    2000-01-01

    Consider migration to a higher income region as a human capital investment in which parents bear migration costs and children share returns. Migrants from a population with heterogeneous intergenerational discount rates will be self-selected on intergenerational altruism. Thus, immigrants may be self-selected on fertility. Soviet Jews who migrate to Israel despite high migration costs have significantly more children than members of the same birth cohort who migrate later when costs are low. ...

  17. Governing Global Migration

    OpenAIRE

    2008-01-01

    This study explores the global regulative function of migration politics. Its main aim is to rethink migration politics through an engagement with the Foucauldian governmentality perspective, which focuses on the relation between government and thought. A secondary aim is to use this perspective to explore the global description of migration and migration politics which is emerging with the currently evolving global governance of migration. Doing so, it wishes to contribute both to the study ...

  18. Migration behaviour of twaite shad Alosa fallax assessed by otolith Sr:Ca and Ba:Ca profiles.

    Science.gov (United States)

    Magath, V; Marohn, L; Fietzke, J; Frische, M; Thiel, R; Dierking, J

    2013-06-01

    Individual migration behaviour during the juvenile and adult life phase of the anadromous twaite shad Alosa fallax in the Elbe estuary was examined using otolith Sr:Ca and Ba:Ca profiles. Between hatching and the end of the first year of life, juveniles showed two migration patterns. Pattern one exhibited a single downstream migration from fresh water to the sea with no return into fresh water. In contrast, pattern two showed a first migration into the sea, then a return into fresh water and, finally, a second downstream migration into marine water. This first report of migration plasticity for A. fallax points to different exposure times to estuarine threats depending on the migration strategy. In adults, high Sr:Ca and low Ba:Ca in the majority of individuals confirmed prior reports of a primarily marine habitat use. Patterns reflecting spawning migrations were rarely observed on otoliths, possibly due to the short duration of visits to fresh water.

  19. 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.

  20. Bmx is a downstream Rap1 effector in VEGF-induced endothelial cell activation.

    Science.gov (United States)

    Stoletov, Konstantin V; Terman, Bruce I

    2004-07-16

    We had previously shown that Rap1 mediates certain of the signaling pathways involved in VEGF-induced endothelial cell migration, although the downstream Rap1 effectors are not known. Towards the goal of identifying those effectors, we utilized a commercially available antibody array filter to identify proteins that either directly interact with Rap1 or interact indirectly through a multi-protein complex. The protocol identified 10 possible Rap1-interacting proteins, including the Bmx non-receptor tyrosine kinase. The conclusion that VEGF treatment leads to a Rap1/Bmx complex was confirmed by an experiment in which cell lysates from VEGF and control cells were immunoprecipitated with Bmx antibodies and Western blotting was done using anti-Rap1 antibodies. VEGF treatment led to the recruitment of Bmx to the CAS scaffolding protein, and inhibition of the Bmx kinase blocked VEGF-induced cell migration. Formation of a Rap1/Bmx complex was not observed in cells transfected with an expression vector for a dominant-negative Rap1, indicating that Bmx is a downstream Rap1 effector in VEGF-induced endothelial cell activation.

  1. Downstream Evolution of Longitudinal Embedded Vortices with Helical Structure

    DEFF Research Database (Denmark)

    Velte, Clara Marika; Okulov, Valery; Hansen, Martin Otto Laver

    2009-01-01

    In the present work the downstream development of device induced vortices with helical symmetry embedded in wall bounded flow on a bump is studied with the aid of Stereoscopic Particle Image Velocimetry (SPIV). The downstream evolution of characteristic parameters of helical vortices is studied...

  2. Taking Aim at Moving Targets in Computational Cell Migration.

    Science.gov (United States)

    Masuzzo, Paola; Van Troys, Marleen; Ampe, Christophe; Martens, Lennart

    2016-02-01

    Cell migration is central to the development and maintenance of multicellular organisms. Fundamental understanding of cell migration can, for example, direct novel therapeutic strategies to control invasive tumor cells. However, the study of cell migration yields an overabundance of experimental data that require demanding processing and analysis for results extraction. Computational methods and tools have therefore become essential in the quantification and modeling of cell migration data. We review computational approaches for the key tasks in the quantification of in vitro cell migration: image pre-processing, motion estimation and feature extraction. Moreover, we summarize the current state-of-the-art for in silico modeling of cell migration. Finally, we provide a list of available software tools for cell migration to assist researchers in choosing the most appropriate solution for their needs.

  3. Return migration to Italy and labour migration.

    Science.gov (United States)

    Calvaruso, C

    1983-01-01

    The problems caused by large-scale return migration to Italy in recent years are considered. The importance of the additional skills and capital acquired by these migrants while abroad is stressed. Extensive data on the volume of return migration in the 1970s are included.

  4. Surgical Assisting

    Science.gov (United States)

    ... Insert and remove Foley urinary bladder catheter Place pneumatic tourniquet Confirm procedure with surgeon Drape patient within ... Technology and Surgical Assisting (NBSTSA) offers the CertifiedSurgical First Assistant (CSFA) credential, and the National Surgical Assistant ...

  5. Freshwater and coastal migration patterns in the silver-stage eel Anguilla anguilla.

    Science.gov (United States)

    Barry, J; Newton, M; Dodd, J A; Lucas, M C; Boylan, P; Adams, C E

    2016-02-01

    The unimpeded downstream movement patterns and migration success of small female and male Anguilla anguilla through a catchment in north-west Europe were studied using an acoustic hydrophone array along the River Finn and into the Foyle Estuary in Ireland. Twenty silver-stage A. anguilla (total length, LT , range: 332-520 mm) were trapped 152 km upstream from a coastal marine sea-lough outlet and internally tagged with acoustic transmitters of which 19 initiated downstream migration. Migration speed was highly influenced by river flow within the freshwater (FW) compartment. Anguilla anguilla activity patterns were correlated with environmental influences; light, tidal direction and lunar phase all influenced the initiation of migration of tagged individuals. Migration speed varied significantly between upstream and lower river compartments. Individuals migrated at a slower speed in transitional water and sea-lough compartments compared with the FW compartment. While 88·5% survival was recorded during migration through the upper 121 km of the river and estuary, only 26% of A. anguilla which initiated downstream migration were detected at the outermost end of the acoustic array. Telemetry equipment functioned efficiently, including in the sea-lough, so this suggests high levels of mortality during sea-lough migration, or less likely, long-term sea-lough residence by silver A. anguilla emigrants. This has important implications for eel management plans.

  6. 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

  7. 3 CFR - Unexpected Urgent Refugee and Migration Needs Related to the Continuing Conflict in Pakistan

    Science.gov (United States)

    2010-01-01

    ... 3 The President 1 2010-01-01 2010-01-01 false Unexpected Urgent Refugee and Migration Needs... Presidential Determination No. 2009-16 of March 11, 2009 Unexpected Urgent Refugee and Migration Needs Related... Migration and Refugee Assistance Act of 1962 (the “Act”), as amended (22 U.S.C. 2601), I hereby...

  8. 3 CFR - Unexpected Urgent Refugee and Migration Needs Related to Gaza

    Science.gov (United States)

    2010-01-01

    ... 3 The President 1 2010-01-01 2010-01-01 false Unexpected Urgent Refugee and Migration Needs... of January 27, 2009 Unexpected Urgent Refugee and Migration Needs Related to Gaza Memorandum for the..., including section 2(c)(1) of the Migration and Refugee Assistance Act of 1962 (the “Act”), as amended (22...

  9. Sediment Mobilization From Reservoirs Can Cause Short Term Oxygen Depletion In Downstream Receiving Waters

    Science.gov (United States)

    Anderson, C.; Schenk, L.; Bragg, H.; Singer, M.; Hume, N.

    2013-12-01

    Reservoir management can cause incidences of short-term sediment mobilization, e.g. during dam removal or drawdown for maintenance or habitat purposes. Much of the associated planning focuses on predicting, quantifying, and mitigating the physical impacts of sediment mobilization, transport, and deposition. Sediment pulses can cause multiple regulatory and management concerns, such as turbidity or suspended sediment concentrations that may exceed State standards, geomorphic change and effects on property or infrastructure, or wildlife impacts such as stress to fish via gill abrasion or burial of critical habitat. Water-quality issues associated with sediment mobilization, including nutrient and contaminant transport, are often given less attention, presumably because their effects are less immediate or because of resource constraints. Recent experience with large pulses of sediment from several western reservoirs involving dam removals and temporary drawdowns indicates that oxygen demand, leading to depletion of downstream dissolved oxygen (DO), can also be a significant short-term concern. During the October 2011 Condit Dam removal on the White Salmon River in Washington, DO in receiving waters about 4.5 km downstream of the dam dropped to less than 1 mg/L within 2 hours of the demolition; in response, salmonids were observed to be in distress, apparently gulping for air at the water surface. DO remained low for at least 24 hours in this reach, and dead fish were observed. In December 2012, during a drawdown designed to aid juvenile-salmonid migration through Fall Creek Reservoir in Oregon, DO dropped precipitously about 1.5 km downstream as turbidity peaked, and a muted DO decrease was also observed approximately 14 miles further downstream despite a large dilution from unaffected sources. Laboratory experiments and modeling using sediments from reservoirs proposed for removal on the Klamath River, California, demonstrated the likelihood for downstream DO

  10. More Myths of Migration.

    Science.gov (United States)

    Basch, Linda; Lerner, Gail

    1986-01-01

    Challenges "myths" about women and migration, including (1) the causes of migration are economic, not racism; (2) migrant women receive support from feminist groups and trade unions; (3) transnational corporations are positive forces in developing nations; (4) migration today has little impact on family life; and (5) most migrants cluster in…

  11. Migration and Adult Education

    Science.gov (United States)

    Gois, William

    2007-01-01

    The objective of this paper is to highlight the role of adult education as a tool in addressing labour migration issues, specifically those concerning the protection of migrant workers' rights and the transformation of the impact of migration into positive holistic developmental gains. The view of labour migration as a means to forge the economic…

  12. Migration and Literature

    DEFF Research Database (Denmark)

    Frank, Søren

    We live in an age of migration and more and more authors have migrant backgrounds. Migration and Literature offers a thorough and thought provoking examination of the thematic and formal role of migration in four contemporary and canonized novelists, Günter Grass, Milan Kundera, Salman Rushdie...

  13. 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

  14. The "WFD-effect" on upstream-downstream relations in international river basins – insights from the Rhine and the Elbe basins

    Directory of Open Access Journals (Sweden)

    S. Moellenkamp

    2007-06-01

    Full Text Available The upstream-downstream relationship in international river basins is a traditional challenge in water management. Water use in upstream countries often has a negative impact on water use in downstream countries. This is most evident in the classical example of industrial pollution in upstream countries hindering drinking water production downstream. The European Water Framework Directive (WFD gives new impetus to the river basin approach and to international co-operation in European catchments. It aims at transforming a mainly water quality oriented management into a more integrated approach of ecosystem management. After discussing the traditional upstream-downstream relationship, this article shows that the WFD has a balancing effect on upstream-downstream problems and that it enhances river basin solidarity in international basins. While it lifts the downstream countries to the same level as the upstream countries, it also leads to new duties for the downstream states. Following the ecosystem approach, measures taken by downstream countries become increasingly more important. For example, downstream countries need to take measures to allow for migrating fish species to reach upstream stretches of river systems. With the WFD, fish populations receive increased attention, as they are an important indicator for the ecological status. The European Commission acquires a new role of inspection and control in river basin management, which finally also leads to enhanced cooperation and solidarity among the states in a basin. In order to achieve better water quality and to mitigate upstream-downstream problems, also economic instruments can be applied and the WFD does not exclude the possibility of making use of financial compensations, if at the same time the polluter pays principle is taken into account. The results presented in this article originate from a broader study on integrated water resources management conducted at Bonn University and

  15. MATHEMATICAL MODELLING OF DEGRADATION AND FLUVIAL PROCESS DOWNSTREAM RESERVOIRS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    To research into the problem of degradation and fluvial process downstream reservoirs and its influence on flood control and navigation, a 1-D mathematical model of degradation and fluvial process downstream the reservoir was established in this paper. The non-equilibrium transport of non-uniform suspended load, the non-uniform bedload transport and bed material sorting were considered in the model. Some techniques were suggested for some problems in calculation, such as the effective suspended load carrying capacity of the different reaches of bed materials, the coefficient of suspended load carrying capacity, the recovering coefficient of carrying capacity, the mixed layer thickness, the bedload transport width, bifurcation and confluence of main and branch channel, and the distribution of deposition and erosion along the cross section, etc. The model was tested by the data of degradation downstream the Danjiangkou reservoir on the Hanjiang River and the data of degradation downstream the Gezhouba Project on the Yangtze River.

  16. MATHEMATICAL MODEL OF RIVER BED CHANGE DOWNSTREAM OF XIAOLANGDI RESERVOIR

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A mathematical model of river bed change downstream of the Xiaolangdi Reservoir was developed based on the most recent achievement of sediment theory in the Yellow River. The model was verified by the comparison of computed results and measured data from 1986 to 1996. Numerical prediction of the erosion and deposition downstream of the Xiaolangdi Reservoir in its first operation year was carried out, and a series of suggestions were given for reservoir operation mode in its early operation period.

  17. 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.

  18. Perspective: Towards environmentally acceptable criteria for downstream fish passage through mini hydro and irrigation infrastructure in the Lower Mekong River Basin

    Energy Technology Data Exchange (ETDEWEB)

    Baumgartner, Lee J.; Daniel Deng, Z.; Thorncraft, Garry; Boys, Craig A.; Brown, Richard S.; Singhanouvong, Douangkham; Phonekhampeng, Oudom

    2014-01-01

    Tropical rivers have high annual discharges optimal for hydropower and irrigation development. The Mekong River is one of the largest tropical river systems, supporting a unique mega-diverse fish community. Fish are an important commodity in the Mekong, contributing a large proportion of calcium, protein, and essential nutrients to the diet of the local people and providing a critical source of income for rural households. Many of these fish migrate not only upstream and downstream within main-channel habitats but also laterally into highly productive floodplain habitat to both feed and spawn. Most work to date has focused on providing for upstream fish passage, but downstream movement is an equally important process to protect. Expansion of hydropower and irrigation weirs can disrupt downstream migrations and it is important to ensure that passage through regulators or mini hydro systems is not harmful or fatal. Many new infrastructure projects (<6 m head) are proposed for the thousands of tributary streams throughout the Lower Mekong Basin and it is important that designs incorporate the best available science to protect downstream migrants. Recent advances in technology have provided new techniques which could be applied to Mekong fish species to obtain design criteria that can facilitate safe downstream passage. Obtaining and applying this knowledge to new infrastructure projects is essential in order to produce outcomes that are more favorable to local ecosystems and fisheries.

  19. Targeting Protein Kinase C Downstream of Growth Factor and Adhesion Signalling

    Directory of Open Access Journals (Sweden)

    Catríona M. Dowling

    2015-07-01

    Full Text Available The signaling outputs of Receptor Tyrosine Kinases, G-protein coupled receptors and integrins converge to mediate key cell process such as cell adhesion, cell migration, cell invasion and cell proliferation. Once activated by their ligands, these cell surface proteins recruit and direct a diverse range of proteins to disseminate the appropriate response downstream of the specific environmental cues. One of the key groups of proteins required to regulate these activities is the family of serine/threonine intracellular kinases called Protein Kinase Cs. The activity and subcellular location of PKCs are mediated by a series of tightly regulated events and is dependent on several posttranslational modifications and the availability of second messengers. Protein Kinase Cs exhibit both pro- and anti-tumorigenic effects making them an interesting target for anti-cancer treatment.

  20. Targeting Protein Kinase C Downstream of Growth Factor and Adhesion Signalling

    Energy Technology Data Exchange (ETDEWEB)

    Dowling, Catríona M., E-mail: Catriona.Dowling@ul.ie; Kiely, Patrick A., E-mail: Catriona.Dowling@ul.ie [Department of Life Sciences, Materials and Surface Science Institute and Stokes Institute, University of Limerick, Limerick 78666 (Ireland); Health Research Institute (HRI), University of Limerick, Limerick 78666 (Ireland)

    2015-07-15

    The signaling outputs of Receptor Tyrosine Kinases, G-protein coupled receptors and integrins converge to mediate key cell process such as cell adhesion, cell migration, cell invasion and cell proliferation. Once activated by their ligands, these cell surface proteins recruit and direct a diverse range of proteins to disseminate the appropriate response downstream of the specific environmental cues. One of the key groups of proteins required to regulate these activities is the family of serine/threonine intracellular kinases called Protein Kinase Cs. The activity and subcellular location of PKCs are mediated by a series of tightly regulated events and is dependent on several posttranslational modifications and the availability of second messengers. Protein Kinase Cs exhibit both pro- and anti-tumorigenic effects making them an interesting target for anti-cancer treatment.

  1. Malaysia and forced migration

    OpenAIRE

    Arzura Idris

    2012-01-01

    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 Malaysi...

  2. Union Dissolution and Migration

    OpenAIRE

    Cooke, Thomas; Mulder, Clara H.; Thomas, Michael

    2016-01-01

    BACKGROUND While there is a limited body of research regarding residential mobility and migration following union dissolution, there is a particular dearth of studies that go into detail about the factors that shape how union dissolution may result in long-distance migration. OBJECTIVE This research isolates and identifies the processes that influence inter-state migration in the period immediately following the dissolution of a marital union. METHODS Multilevel logit models of the probabilit...

  3. 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...

  4. 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 ...

  5. Assistive Technologies

    Science.gov (United States)

    Auat Cheein, Fernando A., Ed.

    2012-01-01

    This book offers the reader new achievements within the Assistive Technology field made by worldwide experts, covering aspects such as assistive technology focused on teaching and education, mobility, communication and social interactivity, among others. Each chapter included in this book covers one particular aspect of Assistive Technology that…

  6. 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.

  7. 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

    2016-11-30

    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.

  8. Experimental investigation of unsteady fan flow interaction with downstream struts

    Science.gov (United States)

    Ng, W. F.; Obrien, W. F.; Olsen, T. L.

    1986-07-01

    In the present study of the unsteady pressure field produced on fan rotor blades by interaction with downstream struts, a single stage, low speed axial-flow fan was instrumented with blade-mounted high frequency pressure transducers. In addition, stationary pressure problems were used to map out the flowfield. Fluctuating pressure measurements are presented for blade midspan and 85-percent span on both the suction and pressure surfaces of the rotor blades at several positions of the downstream struts, and for two different flow coefficients. The strut is found to produce an effect on the unsteady pressure field on the rotor blades; this effect exceeds that due to the stator at design rotor-stator-strut spacing, but it rapidly declines as the struts are moved downstream.

  9. International Migration of Couples

    DEFF Research Database (Denmark)

    Junge, Martin; Munk, Martin D.; Poutvaara, Panu

    2017-01-01

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

  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. 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...

  12. 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 a

  13. Geography of European Migration

    Directory of Open Access Journals (Sweden)

    Zhitin Dmitry V.

    2016-08-01

    Full Text Available In recent decades, the role of international migration has increased dramatically in most European countries. The growth in migration has made some authors proclaim the beginning of a second Migration Period that could transform the social and cultural identity of Europe. The article presents an analysis of international migration geography in Europe in the last twenty-five years. The authors identify the main trends in migration, provide migration profiles of European countries, and propose a classification based on the recent changes in the migrant stock. Changes in the migrant stock (total emigration and immigration reflect the level of involvement in international and global processes. They can serve as an indicator of a country’s attractiveness for both foreigners and the country’s citizens. The study shows that European countries are increasingly split into ‘immigrant’ and ‘emigrant’ states. The authors describe spatial patterns of migration. The volume and localisation of migration flows in Europe are affected not only by cultural and historical circumstance, such as a colonial past or a common language. The scale of immigrant influx often does not depend on a donor country’s demographic potential or the level of its socio-economic development. The links between the place of origin and destination are often more complex than it might initially seem. The authors stress the importance of a differentiated immigration policy taking into account ethnic and cultural features of host societies.

  14. Model Migration Schedules

    OpenAIRE

    1981-01-01

    This report draws on the fundamental regularity exhibited by age profiles of migration all over the world to develop a system of hypothetical model schedules that can be used in multiregional population analyses carried out in countries that lack adequate migration data.

  15. 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...

  16. Ventricular assist device

    Science.gov (United States)

    VAD; RVAD; LVAD; BVAD; Right ventricular assist device; Left ventricular assist device; Biventricular assist device; Heart pump; Left ventricular assist system; LVAS; Implantable ventricular assist device

  17. Transition duct with divided upstream and downstream portions

    Energy Technology Data Exchange (ETDEWEB)

    McMahan, Kevin Weston; LeBegue, Jeffrey Scott; Maldonado, Jaime Javier; Dillard, Daniel Jackson; Flanagan, James Scott

    2015-07-14

    Turbine systems are provided. In one embodiment, a turbine system includes a transition duct comprising an inlet, an outlet, and a duct passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of the transition duct is offset from the inlet along the longitudinal axis and the tangential axis. The duct passage includes an upstream portion extending from the inlet and a downstream portion extending from the outlet. The turbine system further includes a rib extending from an outer surface of the duct passage, the rib dividing the upstream portion and the downstream portion.

  18. World Migration Degree Global migration flows in directed networks

    CERN Document Server

    Porat, Idan

    2015-01-01

    In this article we analyze the global flow of migrants from 206 source countries to 145 destination countries (2006-2010) and focus on the differences in the migration network pattern between destination and source counters as represented by its degree and weight distribution. Degree represents the connectivity of a country to the global migration network, and plays an important role in defining migration processes and characteristics. Global analysis of migration degree distribution offers a strong potential contribution to understanding of migration as a global phenomenon. In regard to immigration, we found that it is possible to classify destination countries into three classes: global migration hubs with high connectivity and high migration rate; local migration hubs with low connectivity and high migration rate; and local migration hubs with opposite strategy of high connectivity and low migration rate. The different migration strategies of destination countries are emerging from similar and homogenies p...

  19. Trafficking and cell migration.

    Science.gov (United States)

    Ulrich, Florian; Heisenberg, Carl-Philipp

    2009-07-01

    The migration of single cells and epithelial sheets is of great importance for gastrulation and organ formation in developing embryos and, if misregulated, can have dire consequences e.g. during cancer metastasis. A keystone of cell migration is the regulation of adhesive contacts, which are dynamically assembled and disassembled via endocytosis. Here, we discuss some of the basic concepts about the function of endocytic trafficking during cell migration: transport of integrins from the cell rear to the leading edge in fibroblasts; confinement of signalling to the front of single cells by endocytic transport of growth factors; regulation of movement coherence in multicellular sheets by cadherin turnover; and shaping of extracellular chemokine gradients. Taken together, endocytosis enables migrating cells and tissues to dynamically modulate their adhesion and signalling, allowing them to efficiently migrate through their extracellular environment.

  20. 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.

  1. On marriage and migration.

    Science.gov (United States)

    Stark, O

    1988-09-01

    Marriage, migration, and related phenomena such as marital stability, fertility, and investment in human capital may be better explained by studying marriage and migration jointly. This paper examines the role of migration in obtaining joint labor market and marriage market equilibrium. When broadly interpreted, marriage and migration share a number of common features. Both involve search and its resolution (pairing of mates in the former and matching of labor and firms in the latter). In both cases, success in finding a partner is sensitive to the availability of partners and to the distribution of their endowments and traits. Almost always, and along with separation and divorce, marriage mandates spatial relocation which may translate into migration. Both involve a movement that is associated with adjustment costs from 1 state into another. The decisions to enter marriage and undertake employment or the decisions to divorce and quit a job depend on exogenous parameters, some of which are determined by the marriage market and the labor market. Since both marriage and divorce take place in the context of broadly defined markets, they may and often are analyzed applying market concepts, theorems, and solutions. Yet the authors could not pinpoint 1 single, systematic attempt that checks through the interactions between marriage and migration, so this paper attempts to rectify this state of research. Essentially, this paper 1) discusses individual decision making pending possible migration prior to or following marriage, 2) examines whether it is easier for a married couple or a single person to migrate, and 3) considers whether marriage dissolution could cause migration when marriage is the only reason that has kept a spouse from moving. This integrated research agenda for both marriage and migration can delineate interesting new implications to examine.

  2. Ivabradine Reduces Chemokine-Induced CD4-Positive Lymphocyte Migration

    Directory of Open Access Journals (Sweden)

    Thomas Walcher

    2010-01-01

    Full Text Available Aims. Migration of CD4-positive lymphocytes into the vessel wall is a critical step in atherogenesis. Recent data suggest that ivabradine, a selective I(f-channel blocker, reduces atherosclerotic plaque formation in apolipoprotein E-deficient mice, hitherto nothing is known about the mechanism by which ivabradine modulates plaque formation. Therefore, the present study investigated whether ivabradine regulates chemokine-induced migration of lymphocytes. Methods and results. Stimulation of CD4-positive lymphocytes with SDF-1 leads to a 2.0±0.1 fold increase in cell migration (P<.01; n=7. Pretreatment of cells with ivabradine reduces this effect to a maximal 1.2±0.1 fold induction at 0.1 µmol/L ivabradine (P<.01 compared to SDF-1-treated cells, n=7. The effect of ivabradine on CD4-positive lymphocyte migration was mediated through an early inhibition of chemokine-induced PI-3 kinase activity as determined by PI-3 kinase activity assays. Downstream, ivabradine inhibits activation of the small GTPase Rac and phosphorylation of the Myosin Light Chain (MLC. Moreover, ivabradine treatment reduces f-actin formation as well as ICAM3 translocation to the uropod of the cell, thus interfering with two important steps in T cell migration. Conclusion. Ivabradine inhibits chemokine-induced migration of CD4-positive lymphocytes. Given the crucial importance of chemokine-induced T-cell migration in early atherogenesis, ivabradine may be a promising tool to modulate this effect.

  3. Mechanisms contributing to differential regulation of PAX3 downstream target genes in normal human epidermal melanocytes versus melanoma cells.

    Science.gov (United States)

    Bartlett, Danielle; Boyle, Glen M; Ziman, Mel; Medic, Sandra

    2015-01-01

    Melanoma is a highly aggressive and drug resistant form of skin cancer. It arises from melanocytes, the pigment producing cells of the skin. The formation of these melanocytes is driven by the transcription factor PAX3 early during embryonic development. As a result of alternative splicing, the PAX3 gene gives rise to eight different transcripts which encode isoforms that have different structures and activate different downstream target genes involved in pathways of cell proliferation, migration, differentiation and survival. Furthermore, post-translational modifications have also been shown to alter the functions of PAX3. We previously identified PAX3 downstream target genes in melanocytes and melanoma cells. Here we assessed the effects of PAX3 down-regulation on this panel of target genes in primary melanocytes versus melanoma cells. We show that PAX3 differentially regulates various downstream target genes involved in cell proliferation in melanoma cells compared to melanocytes. To determine mechanisms behind this differential downstream target gene regulation, we performed immunoprecipitation to assess post-translational modifications of the PAX3 protein as well as RNAseq to determine PAX3 transcript expression profiles in melanocytes compared to melanoma cells. Although PAX3 was found to be post-translationally modified, there was no qualitative difference in phosphorylation and ubiquitination between melanocytes and melanoma cells, while acetylation of PAX3 was reduced in melanoma cells. Additionally, there were differences in PAX3 transcript expression profiles between melanocytes and melanoma cells. In particular the PAX3E transcript, responsible for reducing melanocyte proliferation and increasing apoptosis, was found to be down-regulated in melanoma cells compared to melanocytes. These results suggest that alternate transcript expression profiles activate different downstream target genes leading to the melanoma phenotype.

  4. 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 chemist

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

    DEFF Research Database (Denmark)

    Howells, John

    Merges and Nelson have proposed that pioneer patents have enabled their owners to 'block' or 'hold-up' downstream innovation in cases as important as the car, radio, aircraft and electric lighting (Merges and Nelson 1990, ; Merges and Nelson 1994). Merges and Nelson use their work to question...

  6. Modeling downstream fining in sand-bed rivers. II: Application

    Science.gov (United States)

    Wright, S.; Parker, G.

    2005-01-01

    In this paper the model presented in the companion paper, Wright and Parker (2005) is applied to a generic river reach typical of a large, sand-bed river flowing into the ocean in order to investigate the mechanisms controlling longitudinal profile development and downstream fining. Three mechanisms which drive downstream fining are studied: a delta prograding into standing water, sea-level rise, and tectonic subsidence. Various rates of sea-level rise (typical of the late Holocene) and tectonic subsidence are modeled in order to quantify their effects on the degree of profile concavity and downstream fining. Also, several other physical mechanisms which may affect fining are studied, including the relative importance of the suspended versus bed load, the effect of the loss of sediment overbank, and the influence of the delta bottom slope. Finally, sensitivity analysis is used to show that the grain-size distribution at the interface between the active layer and substrate has a significant effect on downstream fining. ?? 2005 International Association of Hydraulic Engineering and Research.

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

    NARCIS (Netherlands)

    Andonowati,; Karjanto, N.; Groesen, van E.

    2006-01-01

    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 le

  8. DNS and RANS Simulation of Dispersion Downstream of an Obstacle

    Science.gov (United States)

    2008-12-01

    DNS AND RANS SIMULATION OF DISPERSION DOWNSTREAM OF AN OBSTACLE Riccardo Rossi*, Gianluca Iaccarino** * Laboratorio di Termofluidodinamica...ORGANIZATION NAME(S) AND ADDRESS(ES) Laboratorio di Termofluidodinamica Computazionale, Seconda Facolt‘a di Ingegneria di Forl‘ý Universit‘a di Bologna

  9. 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...

  10. Migration without migraines

    Energy Technology Data Exchange (ETDEWEB)

    Lines, L.; Burton, A.; Lu, H.X. [Memorial Univ. of Newfoundland, St. John`s (Canada)

    1994-12-31

    Accurate velocity models are a necessity for reliable migration results. Velocity analysis generally involves the use of methods such as normal moveout analysis (NMO), seismic traveltime tomography, or iterative prestack migration. These techniques can be effective, and each has its own advantage or disadvantage. Conventional NMO methods are relatively inexpensive but basically require simplifying assumptions about geology. Tomography is a more general method but requires traveltime interpretation of prestack data. Iterative prestack depth migration is very general but is computationally expensive. In some cases, there is the opportunity to estimate vertical velocities by use of well information. The well information can be used to optimize poststack migrations, thereby eliminating some of the time and expense of iterative prestack migration. The optimized poststack migration procedure defined here computes the velocity model which minimizes the depth differences between seismic images and formation depths at the well by using a least squares inversion method. The optimization methods described in this paper will hopefully produce ``migrations without migraines.``

  11. 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.

  12. 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....

  13. Global Governance of Migration

    OpenAIRE

    2011-01-01

    The aim of this thesis is to analyze the recently formed global governance of migration, which has got an unprecedented trans-boundary nature due to the impacts og globalization in the post Cold War era. 

  14. 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.

  15. 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

  16. Astrocytes in Migration.

    Science.gov (United States)

    Zhan, Jiang Shan; Gao, Kai; Chai, Rui Chao; Jia, Xi Hua; Luo, Dao Peng; Ge, Guo; Jiang, Yu Wu; Fung, Yin-Wan Wendy; Li, Lina; Yu, Albert Cheung Hoi

    2017-01-01

    Cell migration is a fundamental phenomenon that underlies tissue morphogenesis, wound healing, immune response, and cancer metastasis. Great progresses have been made in research methodologies, with cell migration identified as a highly orchestrated process. Brain is considered the most complex organ in the human body, containing many types of neural cells with astrocytes playing crucial roles in monitoring normal functions of the central nervous system. Astrocytes are mostly quiescent under normal physiological conditions in the adult brain but become migratory after injury. Under most known pathological conditions in the brain, spinal cord and retina, astrocytes are activated and become hypertrophic, hyperplastic, and up-regulating GFAP based on the grades of severity. These three observations are the hallmark in glia scar formation-astrogliosis. The reactivation process is initiated with structural changes involving cell process migration and ended with cell migration. Detailed mechanisms in astrocyte migration have not been studied extensively and remain largely unknown. Here, we therefore attempt to review the mechanisms in migration of astrocytes.

  17. Patents and Downstream Innovation Suppresion - Facts or Fiction?

    DEFF Research Database (Denmark)

    Howells, John

    Merges and Nelson have proposed that pioneer patents of "broad" scope (where the claimed scope is typically broader than that strictly justified by the invention) enable their owners to "block" or "hold-up" downstream innovation.[1] They claim to have illustrated this thesis in such important cases...... of development as aircraft, the car, radio and electric lighting. Merges and Nelson quite logically use their work to question the value of Kitch's prospect theory of patents,[2] a theory that emphasises that the social value of patents is that they enable the coordination of technological development....... This article re-examines Merges and Nelson's illustrative historical-empirical evidence and finds their thesis of downstream innovation suppression to be unwarranted by their empirical evidence.[3] Instead, Merges and Nelson have selected a number of important historical cases in which the administration...

  18. Downstream plasma parameters in laminar shocks from ion kinetics

    Science.gov (United States)

    Gedalin, M.

    2016-10-01

    Ion dynamics in oblique shocks is governed by the macroscopic electric and magnetic fields of the shock front. In laminar shocks, these fields are time-independent and depend only on the coordinate along the shock normal. The shock ramp is narrow and the ion motion across the shock is manifestly non-adiabatic. The ion distribution just behind the ramp is significantly non-gyrotropic. Gyrotropy is achieved well behind the ramp mainly due to the gyrophase mixing. The asymptotic values of the ion density and temperature are determined by the eventual collisionless relaxation of the gyrating ion distribution. Given a distribution at the downstream edge of the ramp, the moments of the distribution after gyrophase mixing are derived using proper spatial averaging. The obtained expressions can be used for independent determination of the downstream plasma state and implementation in Rankine-Hugoniot relations.

  19. Upstream-downstream cooperation approach in Guanting Reservoir watershed

    Institute of Scientific and Technical Information of China (English)

    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.

  20. 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.

  1. Supply Chain Modeling: Downstream Risk Assessment Methodology (DRAM)

    Science.gov (United States)

    2013-12-05

    Supply Chain Modeling: Downstream Risk Assessment Methodology (DRAM) Dr. Sean Barnett December 5, 2013 Institute for Defense Analyses Alexandria, Virginia DMSMS Conference 2013 These Slides are Unclassified and Not Proprietary Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the

  2. Unsteady Interaction Between a Transonic Turbine Stage and Downstream Components

    OpenAIRE

    Davis Roger; Yao Jixian; Clark John; Stetson Gary; Alonso Juan; Jameson Antony; Haldeman Charles; Dunn Michael

    2004-01-01

    Results from a numerical simulation of the unsteady flow through one quarter of the circumference of a transonic high-pressure turbine stage, transition duct, and low-pressure turbine first vane are presented and compared with experimental data. Analysis of the unsteady pressure field resulting from the simulation shows the effects of not only the rotor/stator interaction of the high-pressure turbine stage but also new details of the interaction between the blade and the downstream transition...

  3. Innovation Incentive of Downstream Firms in Stackelberg Duopoly Model

    Institute of Scientific and Technical Information of China (English)

    Guo Hongzhen; Yan Qingyou; Huang Wenjie

    2006-01-01

    The licensing strategies and innovation incentives of downstream firms in a Stackelberg duopoly model were analyzed under three respective assumptions that upstream industry is monopoly, duopoly, or perfect competition. It is found that the Stackelberg firm may license his drastic innovation by a fixed royalty rate which is lower than innovation size. The incentives of drastic innovation of Stackelberg firm facing input suppliers with market power decrease considerably even under royalty licensing,compared with facing perfectly competitive input market.

  4. 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.

  5. MMP14 as a novel downstream target of VEGFR2 in migratory glioma-tropic neural stem cells

    Directory of Open Access Journals (Sweden)

    Nikita G. Alexiades

    2015-11-01

    Full Text Available Neural stem cell (NSC-based carriers have been presented as promising therapeutic tools for the treatment of infiltrative brain tumors due to their intrinsic tumor homing property. They have demonstrated the ability to migrate towards distant tumor microsatellites and effectively deliver the therapeutic payload, thus significantly improving survival in experimental animal models for brain tumor. Despite such optimistic results, the efficacy of NSC-based anti-cancer therapy has been limited due to the restricted tumor homing ability of NSCs. To examine this issue, we investigated the mechanisms of tumor-tropic migration of an FDA-approved NSC line, HB1.F3.CD, by performing a gene expression analysis. We identified vascular endothelial growth factor-A (VEGFA and membrane-bound matrix metalloproteinase (MMP14 as molecules whose expression are significantly elevated in migratory NSCs. We observed increased expression of VEGF receptor 2 (VEGFR2 in the focal adhesion complexes of migratory NSCs, with downstream activation of VEGFR2-dependent kinases such as p-PLCγ, p-FAK, and p-Akt, a signaling cascade reported to be required for cellular migration. In an in vivo orthotopic glioma xenograft model, analysis of the migratory trail showed that NSCs maintained expression of VEGFR2 and preferentially migrated within the perivascular space. Knockdown of VEGFR2 via shRNAs led to significant downregulation of MMP14 expression, which resulted in inhibited tumor-tropic migration. Overall, our results suggest, the involvement of VEGFR2-regulated MMP14 in the tumor-tropic migratory behavior of NSCs. Our data warrant investigation of MMP14 as a target for enhancing the migratory properties of NSC carriers and optimizing the delivery of therapeutic payloads to disseminated tumor burdens.

  6. Planet Formation with Migration

    CERN Document Server

    Chambers, J E

    2006-01-01

    In the core-accretion model, gas-giant planets form solid cores which then accrete gaseous envelopes. Tidal interactions with disk gas cause a core to undergo inward type-I migration in 10^4 to 10^5 years. Cores must form faster than this to survive. Giant planets clear a gap in the disk and undergo inward type-II migration in <10^6 years if observed disk accretion rates apply to the disk as a whole. Type-II migration times exceed typical disk lifetimes if viscous accretion occurs mainly in the surface layers of disks. Low turbulent viscosities near the midplane may allow planetesimals to form by coagulation of dust grains. The radius r of such planetesimals is unknown. If r<0.5 km, the core formation time is shorter than the type-I migration timescale and cores will survive. Migration is substantial in most cases, leading to a wide range of planetary orbits, consistent with the observed variety of extrasolar systems. When r is of order 100m and midplane alpha is of order 3 times 10^-5, giant planets si...

  7. Biometrics and international migration.

    Science.gov (United States)

    Redpath, Jillyanne

    2007-01-01

    This paper will focus on the impact of the rapid expansion in the use of biometric systems in migration management on the rights of individuals; it seeks to highlight legal issues for consideration in implementing such systems, taking as the starting point that the security interests of the state and the rights of the individual are not, and should not be, mutually exclusive. The first part of this paper briefly describes the type of biometric applications available, how biometric systems function, and those used in migration management. The second part examines the potential offered by biometrics for greater security in migration management, and focuses on developments in the use of biometrics as a result of September 11. The third part discusses the impact of the use of biometrics in the management of migration on the individual's right to privacy and ability to move freely and lawfully. The paper highlights the increasing need for domestic and international frameworks to govern the use of biometric applications in the migration/security context, and proposes a number of issues that such frameworks could address.

  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. 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

  10. Elderly Care and Intrafamily Resource Allocation when Children Migrate

    Science.gov (United States)

    Antman, Francisca M.

    2012-01-01

    This paper considers the intrafamily allocation of elderly care in the context of international migration where migrant children may be able to provide financial assistance to their parents but are unable to offer physical care. To investigate sibling interaction, I estimate best response functions for individual physical and financial…

  11. 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....

  12. Analysing immune cell migration.

    Science.gov (United States)

    Beltman, Joost B; Marée, Athanasius F M; de Boer, Rob J

    2009-11-01

    The visualization of the dynamic behaviour of and interactions between immune cells using time-lapse video microscopy has an important role in modern immunology. To draw robust conclusions, quantification of such cell migration is required. However, imaging experiments are associated with various artefacts that can affect the estimated positions of the immune cells under analysis, which form the basis of any subsequent analysis. Here, we describe potential artefacts that could affect the interpretation of data sets on immune cell migration. We propose how these errors can be recognized and corrected, and suggest ways to prevent the data analysis itself leading to biased results.

  13. 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

  14. 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

  15. Making Migration Meaningful

    DEFF Research Database (Denmark)

    Benwell, Ann Fenger

    2013-01-01

    . The article focuses on changing patterns of mobility in the Mongolian ‘age of the market’ and its effects on population groups. Internal and international migration has continually risen as individuals and families have moved to places of opportunity. Connections are believed to be maintained during periods...... 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...

  16. Migration strategies of insects.

    Science.gov (United States)

    Dingle, H

    1972-03-24

    Physiological and ecological results from a variety of species are consistent with what seem to be valid general statements concerning insect migration. These are as follows: (i)During migration locomotory functions are enhanced and vegetative functions such as feeding and reproduction are suppressed. (ii) Migration usually occurs prereproductively in the life of the adult insect (the oogenesis-flight syndrome). (iii)Since migrant individuals are usually prereproductive, their reproductive values, and hence colonizing abilities, are at or near maximum. (iv) Migrants usually reside in temporary habitats. (v)Migrants have a high potential for population increase, r, which is also advantageous for colonizers. (vi)Both the physiological and ecological parameters of migration are modifiable by environmental factors (that is, phenotypically modifiable)to suit the prevailing conditions. Taken together, these criteria establish a comprehensive theory and adumbrate the basic strategy for migrant insects. This basic strategy is modified to suit the ecological requirements of individual species. Comparative studies of these modifications are of considerable theoretical and practical interest, the more so since most economically important insects are migrants. No satisfactory general statements can as yet be made with respect to the genotype and migration. Certainly we expect colonizing populiations to possess genotypes favoring a high r, but genotypic variation in r depends on the heritabilities of life table statistics, and such measurements are yet to be made (10, 53). The fact that flight duration can be increased by appropriate selection in Oncopeltus fasciatus, and the demonstration of additive genetic variance for this trait in Lygaeus kalmii, suggest that heritability studies of migratory behavior would also be worth pursuing. Most interesting of course, will be possible genetic correlations between migration and life history parameters. Also, migration often

  17. Hydroeconomic optimization of reservoir management under downstream water quality constraints

    DEFF Research Database (Denmark)

    Davidsen, Claus; Liu, Suxia; Mo, Xingguo;

    2015-01-01

    low increase to 16.4. billion. CNY/year. Dilution plays an important role and increases the share of surface water allocations to users situated furthest downstream in the system. The modeling framework generates decision rules that result in the economically efficient strategy for complying with both...... a variant of stochastic dynamic programming known as the water value method. Nonlinearity arising from the water quality constraints is handled with an effective hybrid method combining genetic algorithms and linear programming. Untreated pollutant loads are represented by biochemical oxygen demand (BOD...

  18. 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.

  19. Enhanced mixing downstream of a pile in an estuarine flow

    Science.gov (United States)

    Lass, H. U.; Mohrholz, V.; Knoll, M.; Prandke, H.

    2008-11-01

    We studied the impact on stratification and mixing of a bridge pile in a stratified shear flow at the Western Bridge of the Great Belt Fixed Link, Denmark, in January and April 2006. Stratification was measured with high horizontal resolution by towed CTD chains and dissipation of turbulent kinetic energy was measured by a free-falling MSS 90 microstructure profiler equipped with shear probes. Background stratification and current were measured by standard CTD and a bottom-mounted ADCP, respectively. The spatial and temporal variability of the flow field close behind a single pile was measured by an ADCP mounted on a small catamaran tethered to this pile. A shear background flow of varying strength was observed with an inflow of up to 80 cm s - 1 in the surface layer and an outflow of 10 cm s - 1 in the bottom layer. The brackish surface layer was separated from the saline Kattegat water in the bottom layer by an intermediate layer resulting in a Brunt-Väisälä frequency of up to 100 cycles per hour (cph). The maximum Reynolds number ( Re) and internal Froude number ( Fr) were 4.6 × 10 6 and 1.3, respectively. Eddies occurred downstream of a pile with a characteristic diameter of the pile and a frequency corresponding to a von Kármán vortex street when near-surface Fr > 0.7. Enhanced mixing was observed in the von Kármán vortex streets, which caused an increase in salinity by a few psu in the surface mixed layer of the eddy up to 400 m downstream of the piles. Differential advection by cross-channel circulation smeared out laterally from the wakes' salinity anomalies and turbulence. The dissipation of turbulent kinetic energy in the intermediate layer increased by an order of magnitude downstream of the piles as a function of Fr when Fr > 0.7. This enhanced mixing reduced the mean potential energy anomaly downstream by some 10 Jm - 3 in the upper 15 m depth and caused an upstream-directed baroclinic pressure gradient of the same order as the barotropic

  20. Migration scenarii in extrasolar systems

    Directory of Open Access Journals (Sweden)

    Crida A.

    2011-02-01

    Full Text Available In this review talk, I present the theory of type I migration of small mass planets, and its latest developments that open the possibility of outward migration in the inner part of a protoplanetary disk. I also review the type II migration of giant planets, and mention the runaway, type III. Then, we focus on the migration of pairs of planets in resonance. The eccentricity of the planets raise, and possibly their mutual inclination as well. Also, the migration rate can be changed, and directed outward if the outer planet is the lighter. Last, we present a synthetic scenario of migration for the giant planets of our Solar System.

  1. Enhanced migration of seismic data

    Energy Technology Data Exchange (ETDEWEB)

    Carrion, P.M. (PPPG/UFBA, Instituto de Geociencias, Rua Gaetano Moura 123, Federacao, 40.210 Salvador, Bahia (BR))

    1990-10-01

    The so-called enhanced migration which uses diffraction tomography as the repair tool for correction of amplitudes (reflection coefficients) of migrated sections is discussed. As with any linearized procedure, diffraction tomography requires knowledge of the initial model. It is suggested that the initial model is taken as the migrated image. It will be demonstrated that diffraction tomography applied to the data residuals improves the amplitudes of the migrated images. Migration is redefined as the reconstruction of the wavefront sets of distributions (reflection interfaces), and the inversion process as tomographic correction of migrated images.

  2. Migration as Adventure

    DEFF Research Database (Denmark)

    Olwig, Karen Fog

    2017-01-01

    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...

  3. 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...

  4. 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...

  5. 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.

  6. Describing migration spatial structure

    NARCIS (Netherlands)

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

    2002-01-01

    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 d

  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. 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

  9. 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

  10. Upstream and downstream migrations in relation to the reproductive cycle and to environmental factors in the amphipod, Gammarus zaddachi

    NARCIS (Netherlands)

    Dennert, H.G.; Dennert, A.L.; Kant, P.; Pinkster, S.; Stock, J.H.

    1969-01-01

    1. The real identity has been studied of juvenile gammarids, that were found in the fresh-water tidal region of the River Slack (France), 3 to 4 km inland of the mouth of its estuary. At the outset, these juveniles were (on basis of their morphology) considered to belong to Gammarus salinus. 2. Rear

  11. Drosophila Fascin is a novel downstream target of prostaglandin signaling during actin remodeling.

    Science.gov (United States)

    Groen, Christopher M; Spracklen, Andrew J; Fagan, Tiffany N; Tootle, Tina L

    2012-12-01

    Although prostaglandins (PGs)-lipid signals produced downstream of cyclooxygenase (COX) enzymes-regulate actin cytoskeletal dynamics, their mechanisms of action are unknown. We previously established Drosophila oogenesis, in particular nurse cell dumping, as a new model to determine how PGs regulate actin remodeling. PGs, and thus the Drosophila COX-like enzyme Pxt, are required for both the parallel actin filament bundle formation and the cortical actin strengthening required for dumping. Here we provide the first link between Fascin (Drosophila Singed, Sn), an actin-bundling protein, and PGs. Loss of either pxt or fascin results in similar actin defects. Fascin interacts, both pharmacologically and genetically, with PGs, as reduced Fascin levels enhance the effects of COX inhibition and synergize with reduced Pxt levels to cause both parallel bundle and cortical actin defects. Conversely, overexpression of Fascin in the germline suppresses the effects of COX inhibition and genetic loss of Pxt. These data lead to the conclusion that PGs regulate Fascin to control actin remodeling. This novel interaction has implications beyond Drosophila, as both PGs and Fascin-1, in mammalian systems, contribute to cancer cell migration and invasion.

  12. World Migration Degree Global migration flows in directed networks

    OpenAIRE

    2015-01-01

    In this article we analyze the global flow of migrants from 206 source countries to 145 destination countries (2006-2010) and focus on the differences in the migration network pattern between destination and source counters as represented by its degree and weight distribution. Degree represents the connectivity of a country to the global migration network, and plays an important role in defining migration processes and characteristics. Global analysis of migration degree distribution offers a...

  13. Ion Effects in the DARHT-II Downstream Transport

    CERN Document Server

    Chan, Kwok-Chi D; Ekdahl, Carl; Genoni, Thomas C; Hughes, Thomas P; Schulze, Martin E

    2005-01-01

    The DARHT-II accelerator produces an 18-MeV, 2-kA, 2-μs electron beam pulse. After the accelerator, the pulse is delivered to the final focus on an x-ray producing target via a beam transport section called the Downstream Transport. Ions produced due to beam ionization of residual gases in the Downstream Transport can affect the beam dynamics. Ions generated by the head of the pulse will cause modification of space-charge forces at the tail of the pulse so that the beam head and tail will have different beam envelopes. They may also induce ion-hose instability at the tail of the pulse. If these effects are significant, the focusing requirements of beam head and tail at the final focus will become very different. The focusing of the complete beam pulse will be time dependent and difficult to achieve, leading to less efficient x-ray production. In this paper, we will describe the results of our calculations of these ion effects at different residual-gas pressure levels. Our goal is to determine the ma...

  14. PIV measurements and flow characteristics downstream of mangrove root models

    Science.gov (United States)

    Kazemi, Amirkhosro; Curet, Oscar

    2016-11-01

    Mangrove forests attracted attentions as a solution to protect coastal areas exposed to sea-level rising, frequent storms, and tsunamis. Mangrove forests found in tide-dominated flow regions are characterized by their massive and complex root systems, which play a prominent role in the structure of tidal flow currents. To understand the role of mangrove roots in flow structure, we modeled mangrove roots with rigid and flexible arrays of cylinders with different spacing between them as well as different configurations. In this work, we investigate the fluid dynamics downstream of the models using a 2-D time-resolved particle image velocimetry (PIV) and flow visualization. We carried out experiments for four different Reynolds number based on cylinder diameters ranges from 2200 to 12000. We present time-averaged and time-resolved flow parameters including velocity distribution, vorticity, streamline, Reynolds shear stress and turbulent kinetic energy. The results show that the flow structure has different vortex shedding downstream of the cylinders due to interactions of shear layers separating from cylinders surface. The spectral analysis of the measured velocity data is also performed to obtain Strouhal number of the unsteady flow in the cylinder wake.

  15. 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.

  16. Downstream processing of biopharmaceutical proteins produced in plants

    Science.gov (United States)

    Buyel, Johannes Felix; Fischer, Rainer

    2014-01-01

    All biological platforms for the manufacture of biopharmaceutical proteins produce an initially turbid extract that must be clarified to avoid fouling sensitive media such as chromatography resins. Clarification is more challenging if the feed stream contains large amounts of dispersed particles, because these rapidly clog the filter media typically used to remove suspended solids. Charged polymers (flocculants) can increase the apparent size of the dispersed particles by aggregation, facilitating the separation of solids and liquids, and thus reducing process costs. However, many different factors can affect the behavior of flocculants, including the pH and conductivity of the medium, the size and charge distribution of the particulates, and the charge density and molecular mass of the polymer. Importantly, these properties can also affect the recovery of the target protein and the overall safety profile of the process. We therefore used a design of experiments approach to establish reliable predictive models that characterize the impact of flocculants during the downstream processing of biopharmaceutical proteins. We highlight strategies for the selection of flocculants during process optimization. These strategies will contribute to the quality by design aspects of process development and facilitate the development of safe and efficient downstream processes for plant-derived pharmaceutical proteins. PMID:24637706

  17. Vortex structures downstream a lobed nozzle/mixer

    Institute of Scientific and Technical Information of China (English)

    Hui Hu; Toshio Kobayashi

    2008-01-01

    An experimental study was conducted to investigate the evolutions of unsteady vortex structures downstream a lobed mixer/nozzle. A novel dual-plane stereoscopic PIV system was used to measure all 3-components of vorticity distributions to revealed both the large-scale streamwise vortices produced by the lobed mixer/nozzle and the Kelvin-Helmholtz vortex structures generated due to the Kelvin-Helmholtz instabilities simultaneously and quantitatively for the first time. The instantaneous and the ensemble-averaged vorticity distributions displayed quite different aspects about the evolutions of the unsteady vortex structures. While the ensemble-averaged vorticity distributions indicated the overall effect of the special geometry of the lobed nozzle/mixer on the enhanced mixing process, the instantaneous vorticity distributions elucidated many details about how the enhanced mixing process was conducted. In addition to quantitatively confirming conjectures of previous studies, further insight about the formation, evolution and interaction characteristics of the unsteady vortex structures downstream of the lobed mixer/nozzle were also uncovered quantitatively in the present study.

  18. 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

  19. Epac Activation Regulates Human Mesenchymal Stem Cells Migration and Adhesion.

    Science.gov (United States)

    Yu, Jiao-Le; Deng, Ruixia; Chung, Sookja K; Chan, Godfrey Chi-Fung

    2016-04-01

    How to enhance the homing of human mesenchymal stem cells (hMSCs) to the target tissues remains a clinical challenge nowadays. To overcome this barrier, the mechanism responsible for the hMSCs migration and engraftment has to be defined. Currently, the exact mechanism involved in migration and adhesion of hMSCs remains unknown. Exchange protein directly activated by cAMP (Epac), a novel protein discovered in cAMP signaling pathway, may have a potential role in regulating cells adhesion and migration by triggering the downstream Rap family signaling cascades. However, the exact role of Epac in cells homing is elusive. Our study evaluated the role of Epac in the homing of hMSCs. We confirmed that hMSCs expressed functional Epac and its activation enhanced the migration and adhesion of hMSCs significantly. The Epac activation was further found to be contributed directly to the chemotactic responses induced by stromal cell derived factor-1 (SDF-1) which is a known chemokine in regulating hMSCs homing. These findings suggested Epac is connected to the SDF-1 signaling cascades. In conclusion, our study revealed that Epac plays a role in hMSCs homing by promoting adhesion and migration. Appropriate manipulation of Epac may enhance the homing of hMSCs and facilitate their future clinical applications.

  20. The International Organization for Migration in Global Migration Governance

    OpenAIRE

    2011-01-01

    This project focuses on the IOM, the notion of global governance of migration and the interaction between these two. The point of departure has been an attempt to grasp the current global approach to migration and comprehend whether, or to what degree, there is governance of migration issues taking place at a global level.

  1. Hearing Assistive Technology

    Science.gov (United States)

    ... for the Public / Hearing and Balance Hearing Assistive Technology Hearing Assistive Technology: FM Systems | Infrared Systems | Induction ... Assistive Technology Systems Solutions What are hearing assistive technology systems (HATS)? Hearing assistive technology systems (HATS) are ...

  2. Barriers impede upstream spawning migration of flathead chub

    Science.gov (United States)

    Walters, David M.; Zuellig, Robert E.; Crockett, Harry J.; Bruce, James F.; Lukacs, Paul M.; Fitzpatrick, Ryan M.

    2014-01-01

    Many native cyprinids are declining throughout the North American Great Plains. Some of these species require long reaches of contiguous, flowing riverine habitat for drifting eggs or larvae to develop, and their declining populations have been attributed to habitat fragmentation or barriers (e.g., dams, dewatered channels, and reservoirs) that restrict fish movement. Upstream dispersal is also needed to maintain populations of species with passively drifting eggs or larvae, and prior researchers have suggested that these fishes migrate upstream to spawn. To test this hypothesis, we conducted a mark–recapture study of Flathead Chub Platygobio gracilis within a 91-km reach of continuous riverine habitat in Fountain Creek, Colorado. We measured CPUE, spawning readiness (percent of Flathead Chub expressing milt), and fish movement relative to a channel-spanning dam. Multiple lines of evidence indicate that Flathead Chub migrate upstream to spawn during summer. The CPUE was much higher at the base of the dam than at downstream sites; the seasonal increases in CPUE at the dam closely tracked seasonal increases in spawning readiness, and marked fish moved upstream as far as 33 km during the spawning run. The upstream migration was effectively blocked by the dam. The CPUE of Flathead Chub was much lower upstream of the OHDD than at downstream sites, and barriers limit adult dispersal of these and other plains fishes.

  3. CHARACTERISTICS OF MIGRATION IN ROMANIA

    Directory of Open Access Journals (Sweden)

    Daniela DĂNĂCICĂ

    2010-06-01

    Full Text Available The aim of this research is to study the patterns of migration in Romania. Labor migration in Romania has seen major growth after 1989. Permanent migration rapidly increased in the early years after the revolution, decreasing rapidly thereafter, due to difficulties of obtaining long term residence and work permit in the host countries. However, temporary migration has been found to evolve very dynamically, requiring economic analysis of potential externalities, whether positive or the negative of this phenomenon.

  4. CHARACTERISTICS OF MIGRATION IN ROMANIA

    OpenAIRE

    Daniela DĂNĂCICĂ

    2010-01-01

    The aim of this research is to study the patterns of migration in Romania. Labor migration in Romania has seen major growth after 1989. Permanent migration rapidly increased in the early years after the revolution, decreasing rapidly thereafter, due to difficulties of obtaining long term residence and work permit in the host countries. However, temporary migration has been found to evolve very dynamically, requiring economic analysis of potential externalities, whet...

  5. Large Wood Storage Does Not Decrease Downstream Through a Watershed

    Science.gov (United States)

    Vaughan, M.; Pasternack, G. B.; Senter, A. E.; Dahlke, H. E.

    2013-12-01

    The storage of large wood in streams at the watershed scale has long been characterized as decreasing downstream due to a transport limitation in headwater streams, and a supply limitation in larger rivers. The objective of this study was to test this hypothesis through a field study in the Upper Yuba River watershed in Northern California, USA. While most studies surveyed within the wetted channel at selected reaches of different sizes, this study measured overbank deposits of large wood in addition to those in-channel to reflect the total storage within the active river corridor, and used a stratified random sampling scheme to see if relations held at the watershed scale. The watershed is large (2,874 km2), mountainous, mostly forested, and has been dramatically altered by human activities primarily related to gold mining. One hundred fourteen field sites of varied drainage area sizes were visited, inventoried for large wood (length > 1 m, diameter > 10 cm) storage within the active river corridor, and the volume storage per river length was calculated. Inclusion of floodplains in field surveys illuminates the fact that the distribution of large wood changes within the active river corridor, while the total storage does not decrease downstream. Among many watershed-scale control variables, such as drainage area, stream order, and upslope distance, the local amount of shrub cover and bankfull channel width were the only significant predictors of large wood storage in a multiple linear regression model, both with positive coefficients. A critical literature review was also conducted to investigate the evidence for the common conceptual model. Findings were that (1) the observed downstream trend of large wood storage is largely a function of the methods employed by each study, (2) the use of storage per channel area has confounded the commonly held conceptual model, due to its correlation with channel width, and (3) there is little evidence to support the hypothesis

  6. Guidance signalling regulates leading edge behaviour during collective cell migration of cardiac cells in Drosophila.

    Science.gov (United States)

    Raza, Qanber; Jacobs, J Roger

    2016-11-15

    Collective cell migration is the coordinated movement of cells, which organize tissues during morphogenesis, repair and some cancers. The motile cell membrane of the advancing front in collective cell migration is termed the Leading Edge. The embryonic development of the vertebrate and Drosophila hearts are both characterized by the coordinated medial migration of a bilateral cluster of mesodermal cells. In Drosophila, the cardioblasts form cohesive bilateral rows that migrate collectively as a unit towards the dorsal midline to form the dorsal vessel. We have characterized the collective cell migration of cardioblasts as an in vivo quantitative model to study the behaviour of the Leading Edge. We investigated whether guidance signalling through Slit and Netrin pathways plays a role in cell migration during heart development. Through time-lapse imaging and quantitative assessment of migratory behaviour of the cardioblasts in loss-of-function mutants, we demonstrate that both Slit and Netrin mediated signals are autonomously and concomitantly required to maximize migration velocity, filopodial and lamellipodial activities. Additionally, we show that another Slit and Netrin receptor, Dscam1, the role of which during heart development was previously unknown, is required for both normal migration of cardioblasts and luminal expansion. Leading edge behaviour analysis revealed a dosage dependent genetic interaction between Slit and Netrin receptors suggesting that downstream signalling through these receptors converge on a common output that increases leading edge activity of the cardioblasts. Finally, we found that guidance signalling maintains the balance between epithelial and mesenchymal characteristics of the migrating cardioblasts.

  7. Making Migration Meaningful

    DEFF Research Database (Denmark)

    Benwell, Ann Fenger

    2013-01-01

    . The article focuses on changing patterns of mobility in the Mongolian ‘age of the market’ and its effects on population groups. Internal and international migration has continually risen as individuals and families have moved to places of opportunity. Connections are believed to be maintained during periods......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...... 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...

  8. 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...

  9. Assistive Devices

    Science.gov (United States)

    ... 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 dressed. Some are high-tech tools, such as computers. Others are much simpler, ...

  10. Teaching Assistants.

    Science.gov (United States)

    Feinman, Jay M.

    1991-01-01

    A discussion of teaching assistants (TAs) in the law school looks at the TA's cognitive and affective roles and effective ways to use TAs to reinforce usual forms of learning in the large class; introduce a broadened range of materials, skills, and learning methods; and transform the large class experience. (MSE)

  11. Ethiopia's Grand Renaissance Dam: Implications for Downstream Riparian Countries

    Science.gov (United States)

    Zhang, Y.; Block, P. J.; Hammond, M.; King, A.

    2013-12-01

    Ethiopia has begun seriously developing their significant hydropower potential by launching construction of the Grand Ethiopian Renaissance Dam (GERD) on the Blue Nile River to facilitate local and regional growth. Although this has required substantial planning on Ethiopia's part, no policy dictating the reservoir filling rate strategy has been publicly issued. This filling stage will have clear implications on downstream flows in Sudan and Egypt, complicated by evaporative losses, climate variability, and climate change. In this study, various filling policies and future climate states are simultaneously explored to infer potential streamflow reductions at Lake Nasser, providing regional decision-makers with a set of plausible, justifiable, and comparable outcomes. Schematic of the model framework Box plots of 2017-2032 percent change in annual average streamflow at Lake Nasser for each filling policy constructed from the 100 time-series and weighted precipitation changes. All values are relative to the no dam policy and no changes to future precipitation.

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

    DEFF Research Database (Denmark)

    Howells, John

    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...... of that empirical evidence. They present alleged historical examples of downstream innovation suppression in such important technologies as: Edison's carbon filament light bulb; the automobile; radio; aircraft; the transistor; the computer. This paper presents a contrary interpretation of the role of patents......), when adequate historical context is included in the analysis, the more common problem is revealed to be that the patents at issue were not administered, for example by courts or the US Patent Office, to maintain their prospect function i.e, their ability to enable the coordination of development...

  13. 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.

  14. Efficient industry configurations in downstream gas markets. An empirical assessment

    Energy Technology Data Exchange (ETDEWEB)

    Casarin, Ariel A. [IAE Escuela de Direccion y Negocios, Universidad Austral, Buenos Aires (Argentina)

    2007-03-15

    This paper examines the production technology of the downstream gas industry in order to provide some useful insights into its efficient structure by looking at the optimal size of firms and the productive efficiency reasons for and against their vertical integration. The analysis is based on a restricted cost function model estimated using firm level data for Argentina and Great Britain. The findings provide evidence for the presence of vertical diseconomies between stages. Results indicate that a single transmitter is able to produce the industry's output at lower costs for large market sizes and that several regional firms are able to operate without sacrificing scale economies if gas distribution is integrated with supply. The findings also indicate that a gas retailer experiences constant returns to scale when it supplies a large customer base. Liberalisation could thus result in oligopolistic industry configurations. (Author)

  15. Interactive Learning-driven Innovation in Upstream-Downstream Relations

    DEFF Research Database (Denmark)

    Machikita, Tomohiro; Ueki, Yasushi

    2012-01-01

    This paper presents a simple framework of the innovations that result from interfirm learning through exchanges of engineers in upstream-downstream relations within a production chain. To examine the framework, we empirically investigate the impact of mutual knowledge exchanges on product...... and process innovation using a survey of firm's self-reporting customer and supplier data in Indonesia, the Philippines, Thailand and Vietnam. Evidence from interconnected firms within a production chain suggests that firms with mutual exchanges between engineers and customers achieved product innovations...... with new technologies and new markets. However, this is not true for simple improvement of products or process innovation. Mutual exchanges with engineers between producers and suppliers within a chain can be expected to play an important role in the case of costly innovation and in situations unknown...

  16. Trends in Upstream and Downstream Process Development for Antibody Manufacturing

    Directory of Open Access Journals (Sweden)

    Petra Gronemeyer

    2014-10-01

    Full Text Available A steady increase of product titers and the corresponding change in impurity composition represent a challenge for development and optimization of antibody production processes. Additionally, increasing demands on product quality result in higher complexity of processes and analytics, thereby increasing the costs for product work-up. Concentration and composition of impurities are critical for efficient process development. These impurities can show significant variations, which primarily depend on culture conditions. They have a major impact on the work-up strategy and costs. The resulting “bottleneck” in downstream processing requires new optimization, technology and development approaches. These include the optimization and adaptation of existing unit operations respective to the new separation task, the assessment of alternative separation technologies and the search for new methods in process development. This review presents an overview of existing methods for process optimization and integration and indicates new approaches for future developments.

  17. Enforcement and illegal migration

    OpenAIRE

    Orrenius, Pia

    2014-01-01

    Border enforcement of immigration laws attempts to raise the costs of illegal immigration, while interior enforcement also lowers the benefits. Border and interior enforcement therefore reduce the net benefits of illegal immigration and should lower the probability that an individual will decide to migrate. While some empirical studies find that border and interior enforcement serve as significant deterrents to illegal immigration, immigration enforcement is costly and carries significant uni...

  18. Migration with fiscal externalities.

    Science.gov (United States)

    Hercowitz, Z; Pines, D

    1991-11-01

    "This paper analyses the distribution of a country's population among regions when migration involves fiscal externalities. The main question addressed is whether a decentralized decision making [by] regional governments can produce an optimal population distribution...or a centralized intervention is indispensable, as argued before in the literature.... It turns out that, while with costless mobility the fiscal externality is fully internalized by voluntary interregional transfers, with costly mobility, centrally coordinated transfers still remain indispensable for achieving the socially optimal allocation."

  19. Managing the Mass Migration

    Institute of Scientific and Technical Information of China (English)

    Lan Xinzhen

    2012-01-01

    Big crowds and foul air on the train,frighteningly long queues and fierce clashes at the station...these are common scenes during China's Spring Festival travel rush.The annual travel peak is known as the world's biggest human migration.This year's stampede is still ongoing.Lasting over 40 days,people began retuming to their hometowns on January 8 and the final stragglers will make their way back to the cities by February 16.

  20. Functorial Data Migration

    CERN Document Server

    Spivak, David I

    2010-01-01

    In this paper we present a simple database definition language: that of categories and functors. A database schema is a category and a state is a set-valued functor. We show that morphisms of schemas induce three "data migration functors" that translate states from one schema to the other in canonical ways. Database states form a boolean topos of which the classical "relational algebra" is a fragment. These ideas thus create a new denotational semantics for database theory.

  1. Calpains are downstream effectors of bax-dependent excitotoxic apoptosis.

    Science.gov (United States)

    D'Orsi, Beatrice; Bonner, Helena; Tuffy, Liam P; Düssmann, Heiko; Woods, Ina; Courtney, Michael J; Ward, Manus W; Prehn, Jochen H M

    2012-02-01

    Excitotoxicity resulting from excessive Ca(2+) influx through glutamate receptors contributes to neuronal injury after stroke, trauma, and seizures. Increased cytosolic Ca(2+) levels activate a family of calcium-dependent proteases with papain-like activity, the calpains. Here we investigated the role of calpain activation during NMDA-induced excitotoxic injury in embryonic (E16-E18) murine cortical neurons that (1) underwent excitotoxic necrosis, characterized by immediate deregulation of Ca(2+) homeostasis, a persistent depolarization of mitochondrial membrane potential (Δψ(m)), and insensitivity to bax-gene deletion, (2) underwent excitotoxic apoptosis, characterized by recovery of NMDA-induced cytosolic Ca(2+) increases, sensitivity to bax gene deletion, and delayed Δψ(m) depolarization and Ca(2+) deregulation, or (3) that were tolerant to excitotoxic injury. Interestingly, treatment with the calpain inhibitor calpeptin, overexpression of the endogenous calpain inhibitor calpastatin, or gene silencing of calpain protected neurons against excitotoxic apoptosis but did not influence excitotoxic necrosis. Calpeptin failed to exert a protective effect in bax-deficient neurons but protected bid-deficient neurons similarly to wild-type cells. To identify when calpains became activated during excitotoxic apoptosis, we monitored calpain activation dynamics by time-lapse fluorescence microscopy using a calpain-sensitive Förster resonance energy transfer probe. We observed a delayed calpain activation that occurred downstream of mitochondrial engagement and directly preceded neuronal death. In contrast, we could not detect significant calpain activity during excitotoxic necrosis or in neurons that were tolerant to excitotoxic injury. Oxygen/glucose deprivation-induced injury in organotypic hippocampal slice cultures confirmed that calpains were specifically activated during bax-dependent apoptosis and in this setting function as downstream cell-death executioners.

  2. Downstream evolution of unconfined vortices: mechanical and thermal aspects

    Science.gov (United States)

    Pérez-Saborid, M.; Herrada, M. A.; Gómez-Barea, A.; Barrero, A.

    2002-11-01

    We present a numerical study of the downstream evolution (mechanical and thermal) of vortex-jet cores whose velocity and temperature fields far from the axis match a family of inviscid and non-conducting vortices. The far-velocity field is rotational, except for a particular case which corresponds to the well-known Long's vortex. The evolution of the vortex core depends on both the conditions at a certain upstream station, characterized by the dimensionless value of the velocity at the axis, and a dimensionless swirling parameter L defined as the ratio of the values of the azimuthal and axial velocities outside the vortex core. This numerical study, based on the quasi-cylindrical approximation (QC) of the Navier Stokes equations, determines the conditions under which the vortex evolution proceeds smoothly, eventually reaching an asymptotic self-similar behaviour as described in the literature (Fernández-Feria, Fernández de la Mora & Barrero 1995; Herrada, Pérez-Saborid & Barrero 1999), or breaks in a non-slender solution (vortex breakdown). In particular, the critical value L = Lb(a) beyond which vortex breakdown occurs downstream is a function of a dimensionless parameter a characterizing the axial momentum of the vortex jet at an initial upstream station. It is found numerically that for very large values of a this vortex breakdown criterion tends to an asymptote which is precisely the value L = L* predicted by the self-similar analysis, and beyond which a self-similar structure of the vortex core does not exist. In addition, the computation of the total temperature field provides useful information on the physical mechanisms responsible for the thermal separation phenomenon observed in Ranque Hilsch tubes and other swirling jet devices. In particular, the mechanical work of viscous forces which gives rise to an intense loss of kinetic energy during the initial stages of the evolution has been identified as the physical mechanism responsible for thermal

  3. Role of the PI3K regulatory subunit in the control of actin organization and cell migration

    OpenAIRE

    Jiménez, Concepción; Armas Portela, Rosario; Mellado, Mario; Rodríguez Frade, José M.; Collard, John; Serrano, Antonio; Martínez-Alonso, Carlos; Ávila, Jesús; Carrera, Ana C.

    2000-01-01

    Cell migration represents an important cellular response that utilizes cytoskeletal reorganization as its driving force. Here, we describe a new signaling cascade linking PDGF receptor stimulation to actin rearrangements and cell migration. We demonstrate that PDGF activates Cdc42 and its downstream effector N-WASP to mediate filopodia formation, actin stress fiber disassembly, and a reduction in focal adhesion complexes. Induction of the Cdc42 pathway is independent of phosphoinositide 3-kin...

  4. 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

  5. Gender and migration from Albania.

    Science.gov (United States)

    Stecklov, Guy; Carletto, Calogero; Azzarri, Carlo; Davis, Benjamin

    2010-11-01

    This article examines the dynamics and causes of the shift in the gender composition of migration, and more particularly, in women's access to migration opportunities and decision-making. Our analysis focuses on Albania, a natural laboratory for studying international migration where out-migration was essentially nonexistent from the end of World War II to the end of the 1980s. Interest in the Albanian case is heightened because of the complex layers of inequality existing at the time when migration began: relatively low levels of inequality within the labor market and educational system-a product of the Communist era-while household relations remained heavily steeped in tradition and patriarchy. We use micro-level data from the Albania 2005 Living Standards Measurement Study, including migration histories for family members since migration began. Based on discrete-time hazard models, the analysis shows a dramatic increase in male migration and a gradual and uneven expansion of the female proportion of this international migration. Female migration, which is shown to be strongly associated with education, wealth, and social capital, appears responsive to economic incentives and constraints. Using information on the dependency of female migration to the household demographic structure as well as the sensitivity of female migration to household-level shocks, we show how household-level constraints and incentives affect male and female migration differently. Throughout this period, however, women's migration behavior appears more directly aligned with household-level factors, and there is little evidence to suggest that increased female migration signals rising behavioral independence among Albanian women.

  6. 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.

  7. CALCULATION OF FLOW FIELD AND ANALYSIS OF SPAWNING SITES FOR CHINESE STURGEON IN THE DOWNSTREAM OF GEZHOUBA DAM

    Institute of Scientific and Technical Information of China (English)

    FU Xiao-li; LI Da-mei; JIN Guo-yu

    2007-01-01

    The Chinese sturgeon (Acipenser Sinensis) is one of the unique and important fishery resources in China. Since the construction of the Gezhouba Dam, the traditional migration route of the sturgeon has been blocked; consequently, the length of natural spawning sites is reduced from 800 km in the past to less than 5 km at present. As an endangered species, the Chinese sturgeon has become one of the most conserved aquatic species. In this article, the flow field of its spawning states in the downstream of Gezhouba Dam was simulated and analyzed using N-S equations and turbulence model. Volume Of Fluid (VOF) method with the Finite Volume Method (FVM) was used to simulate the water-air two-phase flow to examine the computed area. On the basis of the ecological-hydraulic characteristics of Chinese sturgeon, the features of the flow field were investigated to provide theoretical support for the proper management of the Three Gorges Reservoir.

  8. Bcl11a (Ctip1) Controls Migration of Cortical Projection Neurons through Regulation of Sema3c.

    Science.gov (United States)

    Wiegreffe, Christoph; Simon, Ruth; Peschkes, Katharina; Kling, Carolin; Strehle, Michael; Cheng, Jin; Srivatsa, Swathi; Liu, Pentao; Jenkins, Nancy A; Copeland, Neal G; Tarabykin, Victor; Britsch, Stefan

    2015-07-15

    During neocortical development, neurons undergo polarization, oriented migration, and layer-type-specific differentiation. The transcriptional programs underlying these processes are not completely understood. Here, we show that the transcription factor Bcl11a regulates polarity and migration of upper layer neurons. Bcl11a-deficient late-born neurons fail to correctly switch from multipolar to bipolar morphology, resulting in impaired radial migration. We show that the expression of Sema3c is increased in migrating Bcl11a-deficient neurons and that Bcl11a is a direct negative regulator of Sema3c transcription. In vivo gain-of-function and rescue experiments demonstrate that Sema3c is a major downstream effector of Bcl11a required for the cell polarity switch and for the migration of upper layer neurons. Our data uncover a novel Bcl11a/Sema3c-dependent regulatory pathway used by migrating cortical neurons.

  9. 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.

  10. 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.

  11. 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

  12. Population, desertification, and migration.

    Science.gov (United States)

    Westing, A H

    1994-01-01

    When an imbalance develops between population numbers and the carrying capacity of the land, the persons thereby displaced are referred to as environmental refugees. The utilization of the land beyond sustainability leads to land degradation and ultimately, desertification. The social and political impacts of long-term environmental migration can be distinguished: a) at the site of origin of the displaced persons by the residual population; b) at rural sites of destination within the nation between the new arrivals and preestablished populations; c) in the cities within the nation; d) in the nonindustrialized foreign countries; and e) in the industrialized foreign countries. In the event that an area which had previously been devoted to pastoralism is converted to agriculture, the displaced pastoralists might respond through armed rebellion. In some instances, the disenchanted urban squatters become a politically restive and even a destabilizing force, as occurred in Sudan in the 1980s, especially in Khartoum and Port Sudan. The foreign countries to which many of the displaced persons are migrating are subjected to increasing levels of migrant-induced economic, cultural, and political strains. The growing problems associated with south-to-north migration across the Mediterranean Sea have recently led France, Italy, Portugal, and Spain to enter into a consultative arrangement with Algeria, Libya, Mauritania, Morocco, and Tunisia. All foreign aid to the nonindustrialized countries that attempts to ameliorate the problem of desertification must adopt integrated approaches that: a) address population issues; b) support environmental education; c) provide for the protection of biodiversity; d) encourage participatory forms of local and national government; e) provide opportunities for income generation outside the livestock sector; and f) foster political security and facilitate ecogeographical (subregional) cooperation.

  13. 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".

  14. 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.

  15. [Obesity, migration and adolescence].

    Science.gov (United States)

    Chamay-Weber, Catherine; Shehu-Brovina, Shqipe; Narring, Françoise

    2012-06-13

    Weight management interventions during adolescence are challenging. Migration adds complexity to this problem, making migrant families more vulnerable. Teenagers confront families to new values transmitted by the host society: opulence, junk food, video games. Obesity should not be seen as a single issue of calories-excess, but must be considered as being part of a larger problem, which takes into account the context of the familial and societal life of the migrants. The caregivers must have an overall view of the situation to provide appropriate approaches to weight management.

  16. The Maf factor Traffic jam both enables and inhibits collective cell migration in Drosophila oogenesis.

    Science.gov (United States)

    Gunawan, Felix; Arandjelovic, Mimi; Godt, Dorothea

    2013-07-01

    Border cell cluster (BCC) migration in the Drosophila ovary is an excellent system to study the gene regulatory network that enables collective cell migration. Here, we identify the large Maf transcription factor Traffic jam (Tj) as an important regulator of BCC migration. Tj has a multifaceted impact on the known core cascade that enables BCC motility, consisting of the Jak/Stat signaling pathway, the C/EBP factor Slow border cells (Slbo), and the downstream effector DE-cadherin (DEcad). The initiation of BCC migration coincides with a Slbo-dependent decrease in Tj expression. This reduction of Tj is required for normal BCC motility, as high Tj expression strongly impedes migration. At high concentration, Tj has a tripartite negative effect on the core pathway: a decrease in Slbo, an increase in the Jak/Stat inhibitor Socs36E, and a Slbo-independent reduction of DEcad. However, maintenance of a low expression level of Tj in the BCC during migration is equally important, as loss of tj function also results in a significant delay in migration concomitant with a reduction of Slbo and consequently of DEcad. Taken together, we conclude that the regulatory feedback loop between Tj and Slbo is necessary for achieving the correct activity levels of migration-regulating factors to ensure proper BCC motility.

  17. 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.

  18. Synthetic Routes to Methylerythritol Phosphate Pathway Intermediates and Downstream Isoprenoids

    Science.gov (United States)

    Jarchow-Choy, Sarah K; Koppisch, Andrew T; Fox, David T

    2014-01-01

    Isoprenoids constitute the largest class of natural products with greater than 55,000 identified members. They play essential roles in maintaining proper cellular function leading to maintenance of human health, plant defense mechanisms against predators, and are often exploited for their beneficial properties in the pharmaceutical and nutraceutical industries. Most impressively, all known isoprenoids are derived from one of two C5-precursors, isopentenyl diphosphate (IPP) or dimethylallyl diphosphate (DMAPP). In order to study the enzyme transformations leading to the extensive structural diversity found within this class of compounds there must be access to the substrates. Sometimes, intermediates within a biological pathway can be isolated and used directly to study enzyme/pathway function. However, the primary route to most of the isoprenoid intermediates is through chemical catalysis. As such, this review provides the first exhaustive examination of synthetic routes to isoprenoid and isoprenoid precursors with particular emphasis on the syntheses of intermediates found as part of the 2C-methylerythritol 4-phosphate (MEP) pathway. In addition, representative syntheses are presented for the monoterpenes (C10), sesquiterpenes (C15), diterpenes (C20), triterpenes (C30) and tetraterpenes (C40). Finally, in some instances, the synthetic routes to substrate analogs found both within the MEP pathway and downstream isoprenoids are examined. PMID:25009443

  19. 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.

  20. Downstream effects of a hydroelectric reservoir on aquatic plant assemblages.

    Science.gov (United States)

    Bernez, Ivan; Haury, Jacques; Ferreira, Maria Teresa

    2002-03-16

    Macrophytes were studied downstream of the Rophémel hydroelectric dam on the River Rance (Côtes d'Armor Department, western France) to assess the effects of hydroelectric functioning on river macrophyte communities. We studied ten representative sections of the hydro-peaking channel on five occasions in 1995 and 1996, on a 15-km stretch of river. Floristic surveys were carried out on sections 50 m in length, and genera of macroalgae, species of bryophyta, hydrophytes, and emergent rhizophytes were identified. For the aquatic bryophytes and spermatophytes section of our study, we compared our results with 19th century floristic surveys, before the dam was built. During the vegetative growth period, the hydro-peaking frequency was low. The plant richness was highest near the dam. The macrophyte communities were highly modified according to the distance to the dam. The frequency and magnitude of hydro-peaking was related to the aquatic macrophyte richness in an Intermediate Disturbance Hypothesis position. However, the results of the eco-historical comparison with 19th century floristic surveys point to the original nature of the flora found at the site. Some floral patterns, seen during both periods and at an interval of 133 years, were indicative of the ubiquity of the aquatic flora and of the plants" adaptability. This demonstrates the importance of taking river basin history into account in such biological surveys.

  1. Downstream Effects of a Hydroelectric Reservoir on Aquatic Plant Assemblages

    Directory of Open Access Journals (Sweden)

    Ivan Bernez

    2002-01-01

    Full Text Available Macrophytes were studied downstream of the Rophémel hydroelectric dam on the River Rance (Côtes d’Armor Department, western France to assess the effects of hydroelectric functioning on river macrophyte communities. We studied ten representative sections of the hydro-peaking channel on five occasions in 1995 and 1996, on a 15-km stretch of river. Floristic surveys were carried out on sections 50 m in length, and genera of macroalgae, species of bryophyta, hydrophytes, and emergent rhizophytes were identified. For the aquatic bryophytes and spermatophytes section of our study, we compared our results with 19th century floristic surveys, before the dam was built. During the vegetative growth period, the hydro-peaking frequency was low. The plant richness was highest near the dam. The macrophyte communities were highly modified according to the distance to the dam. The frequency and magnitude of hydro-peaking was related to the aquatic macrophyte richness in an Intermediate Disturbance Hypothesis position. However, the results of the eco-historical comparison with 19th century floristic surveys point to the original nature of the flora found at the site. Some floral patterns, seen during both periods and at an interval of 133 years, were indicative of the ubiquity of the aquatic flora and of the plants’ adaptability. This demonstrates the importance of taking river basin history into account in such biological surveys.

  2. Hydroeconomic optimization of reservoir management under downstream water quality constraints

    Science.gov (United States)

    Davidsen, Claus; Liu, Suxia; Mo, Xingguo; Holm, Peter E.; Trapp, Stefan; Rosbjerg, Dan; Bauer-Gottwein, Peter

    2015-10-01

    A hydroeconomic optimization approach is used to guide water management in a Chinese river basin with the objectives of meeting water quantity and water quality constraints, in line with the China 2011 No. 1 Policy Document and 2015 Ten-point Water Plan. The proposed modeling framework couples water quantity and water quality management and minimizes the total costs over a planning period assuming stochastic future runoff. The outcome includes cost-optimal reservoir releases, groundwater pumping, water allocation, wastewater treatments and water curtailments. The optimization model uses a variant of stochastic dynamic programming known as the water value method. Nonlinearity arising from the water quality constraints is handled with an effective hybrid method combining genetic algorithms and linear programming. Untreated pollutant loads are represented by biochemical oxygen demand (BOD), and the resulting minimum dissolved oxygen (DO) concentration is computed with the Streeter-Phelps equation and constrained to match Chinese water quality targets. The baseline water scarcity and operational costs are estimated to 15.6 billion CNY/year. Compliance to water quality grade III causes a relatively low increase to 16.4 billion CNY/year. Dilution plays an important role and increases the share of surface water allocations to users situated furthest downstream in the system. The modeling framework generates decision rules that result in the economically efficient strategy for complying with both water quantity and water quality constraints.

  3. 离子液体-超声波辅助萃取火焰原子吸收法测定油画棒中的可迁移微量Cd2+%Ionic Liquid Based Ultrasonic-assisted Extraction Coupled with Flame Atomic Adsorption Spectrometry for the Determination of the Migration of Trace Cadmium in Oil Pastel

    Institute of Scientific and Technical Information of China (English)

    周先波; 江海亮; 周赛春; 钟勇

    2011-01-01

    以离子液体为萃取介质,超声波辅助萃取油画棒中的可迁移微量Cd2,以硝酸溶液反萃取后用火焰原子吸收法测定镉.考察了主要影响因素对萃取效果的影响.结果表明,以1-丁基-3-甲基咪唑六氟磷酸盐离子液体为萃取介质,溶液pH值为9.0、金属螯合剂用量为2.00 mL、离子液体的用量为2.00 mL、反萃剂为4.00 mL1.00mol·L-1硝酸、超声时间为5 min时,萃取率可达99%,富集倍数为25,除Cu2、pb2+外其它干扰离子对Cd2+的萃取影响不大.方法的加标回收率为96% ~ 103%,相对标准偏差(n=11)为1.7%,检出限为0.016 mg·L-1.%A flame atomic absorption spectrometric method coupled with ionic liquids based ultrasonic assisted extraction was developed for the determination of the migration of trace cadmium in oil pastel. The main factors affecting the extraction efficiency, such as pH value, amount of metal chelating, I-onic liquid and nitric acid, ultrasonic extraction time, metal ions interference and chain length of I-onic liquid were studied. The optimal conditions were as follows; pH value; 9.0, metal chelating amount; 2. 00 mL, amount of ionic liquid; 2. 00 mL, amount of nitric acid; 4. 00 mL 1. 00 mol ? L , ultrasonic extraction time; 5 min. Under the optimized conditions, the extraction efficiency of Cd reached up to 99% , and the enrichment times was 25. The other metal ions made no effects on the extraction efficiency of Cd2 + except for Cu2 + and Pb2 + . The recoveries for the method varied from 96% to 103% with relative standard deviation(/I = 11) of 1. 7% , and the detection limit was 0. 016 mg ? L -1.

  4. 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...

  5. Electrochemically induced nanocluster migration

    Energy Technology Data Exchange (ETDEWEB)

    Hartl, Katrin [Lehrstuhl Physikalische Chemie, Technische Universitaet Muenchen, Lichtenbergstr. 4, D-85748 Garching (Germany); Department of Chemistry, CS06, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen O (Denmark); Nesselberger, Markus [Department of Chemistry, CS06, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen O (Denmark); Mayrhofer, Karl J.J. [MPI fuer Eisenforschung, Abt. Grenzflaechenchemie und Oberflaechentechnik, Max-Planck-Strasse 1, D-40237 Duesseldorf (Germany); Kunz, Sebastian; Schweinberger, Florian F.; Kwon, GiHan [Lehrstuhl Physikalische Chemie, Technische Universitaet Muenchen, Lichtenbergstr. 4, D-85748 Garching (Germany); Hanzlik, Marianne [Institut fuer Elektronenmikroskopie, Technische Universitaet Muenchen, Lichtenbergstr. 4, D-85748 Garching (Germany); Heiz, Ueli [Lehrstuhl Physikalische Chemie, Technische Universitaet Muenchen, Lichtenbergstr. 4, D-85748 Garching (Germany); Arenz, Matthias, E-mail: m.arenz@kemi.ku.d [Department of Chemistry, CS06, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen O (Denmark)

    2010-12-30

    In the presented study the influence of electrochemical treatments on size-selected Pt nanoclusters (NCs) supported on amorphous carbon is investigated by means of transmission electron microscopy (TEM). Well-defined Pt NCs are prepared by an ultra-high vacuum (UHV) laser vaporization source and deposited with low kinetic energy ({<=}10 eV/cluster) onto TEM gold grids covered by a thin (2 nm) carbon film. After transfer out of UHV Pt NCs are verified to be uniform in size and randomly distributed on the support. Subsequently, the TEM grids are employed as working electrodes in a standard electrochemical three electrode setup and the Pt nanoclusters are subjected to different electrochemical treatments. It is found that the NC arrangement is not influenced by potential hold conditions (at 0.40 V vs. RHE) or by potential cycling in a limited potential window (V{sub max} = 0.55 V vs. RHE). Upon potential cycling to 1.05 V vs. RHE, however, the NCs migrate on the carbon support. Interestingly, migration in oxygen or argon saturated electrolyte leads to NC coalescence, a mechanism discussed for being responsible for performance degradation of low temperature fuel cells, whereas in carbon monoxide saturated electrolyte the Pt NC agglomerate, but remain separated from each other and thus form distinctive structures.

  6. 76 FR 14269 - Unexpected Urgent Refugee and Migration Needs Related to C[ocirc]te d'Ivoire

    Science.gov (United States)

    2011-03-16

    ... Register. (Presidential Sig.) THE WHITE HOUSE, Washington, March 7, 2011 [FR Doc. 2011-6257 Filed 3-15-11... Unexpected Urgent Refugee and Migration Needs Related to C te d'Ivoire Memorandum for the Secretary of State..., including section 2(c)(1) of the Migration and Refugee Assistance Act of 1962 (the ``Act''), as amended,...

  7. 75 FR 34617 - Unexpected Urgent Refugee and Migration Needs Related to Somalia and Food Pipeline Breaks for...

    Science.gov (United States)

    2010-06-18

    ... Federal Register. (Presidential Sig.) THE WHITE HOUSE, Washington, June 8, 2010. [FR Doc. 2010-14879 Filed... Unexpected Urgent Refugee and Migration Needs Related to Somalia and Food Pipeline Breaks for Refugee and... Migration and Refugee Assistance Act of 1962 (the ``Act''), as amended, (22 U.S.C.2601), I hereby...

  8. 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.

  9. Gender and Migration from Albania

    OpenAIRE

    2010-01-01

    This article examines the dynamics and causes of the shift in the gender composition of migration, and more particularly, in women's access to migration opportunities and decision-making. Our analysis focuses on Albania, a natural laboratory for studying international migration where outmigration was essentially nonexistent from the end of World War II to the end of the 1980s. Interest in the Albanian case is heightened because of the complex layers of inequality existing at the time when mig...

  10. Gender and Migration: Overview Report

    OpenAIRE

    Jolly, Susie; Reeves, Hazel; Piper, Nicola

    2005-01-01

    Abstract. Over the past four decades total numbers of international migrants have more than doubled but the percentage of the world population migrating has remained fairly constant. There are now 175 million international migrants worldwide or approximately 3.5 per cent of the global population – about half of whom are women, despite the common misconception that men are the migrants. This Overview Report on Gender and Migration takes a broad approach to migration – it looks at the gender dy...

  11. Gender and Migration from Albania

    OpenAIRE

    2010-01-01

    This article examines the dynamics and causes of the shift in the gender composition of migration, and more particularly, in women’s access to migration opportunities and decision-making. Our analysis focuses on Albania, a natural laboratory for studying international migration where out-migration was essentially nonexistent from the end of World War II to the end of the 1980s. Interest in the Albanian case is heightened because of the complex layers of inequality existing at the time when mi...

  12. 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.

  13. 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

  14. Extraction and downstream processing of plant-derived recombinant proteins.

    Science.gov (United States)

    Buyel, J F; Twyman, R M; Fischer, R

    2015-11-01

    Plants offer the tantalizing prospect of low-cost automated manufacturing processes for biopharmaceutical proteins, but several challenges must be addressed before such goals are realized and the most significant hurdles are found during downstream processing (DSP). In contrast to the standardized microbial and mammalian cell platforms embraced by the biopharmaceutical industry, there are many different plant-based expression systems vying for attention, and those with the greatest potential to provide inexpensive biopharmaceuticals are also the ones with the most significant drawbacks in terms of DSP. This is because the most scalable plant systems are based on the expression of intracellular proteins in whole plants. The plant tissue must therefore be disrupted to extract the product, challenging the initial DSP steps with an unusually high load of both particulate and soluble contaminants. DSP platform technologies can accelerate and simplify process development, including centrifugation, filtration, flocculation, and integrated methods that combine solid-liquid separation, purification and concentration, such as aqueous two-phase separation systems. Protein tags can also facilitate these DSP steps, but they are difficult to transfer to a commercial environment and more generic, flexible and scalable strategies to separate target and host cell proteins are preferable, such as membrane technologies and heat/pH precipitation. In this context, clarified plant extracts behave similarly to the feed stream from microbes or mammalian cells and the corresponding purification methods can be applied, as long as they are adapted for plant-specific soluble contaminants such as the superabundant protein RuBisCO. Plant-derived pharmaceutical proteins cannot yet compete directly with established platforms but they are beginning to penetrate niche markets that allow the beneficial properties of plants to be exploited, such as the ability to produce 'biobetters' with tailored

  15. Neurotensin is a Versatile Modulator of In Vitro Human Pancreatic Ductal Adenocarcinoma Cell (PDAC Migration

    Directory of Open Access Journals (Sweden)

    Tatjana Mijatovic

    2007-01-01

    Full Text Available Background: While the neurotensin (NT roles in pancreatic cancer growth are well documented, its effects on pancreatic cancer cell migration have not been described. Methods: The NT-induced effects on the migration process of human pancreatic ductal adenocarcinoma cells (PDACs were characterized by means of various assays including computer-assisted video-microscopy, fluorescence microscopy, ELISA-based, small GTPase pull-down and phosphorylation assays. Results: The NT-induced modifications on in vitro PDACs migration largely depended on the extra-cellular matrix environment and cell propensity to migrate collectively or individually. While NT significantly reduced the level of migration of collectively migrating PDACs on vitronectin, it significantly increased the level of individually migrating PDACs. These effects were mainly mediated through the sortilin/NTR3 receptor. Neurotensin both induced altered expression of αV and β5 integrin subunits in PDACs cultured on vitronectin resulting in modified adhesion abilities, and caused modifications to the organization of the actin cytoskeleton through the NT-mediated activation of small Rho GTPases. While the NT effects on individually migrating PDACs were mediated at least through the EGFR/ERK signaling pathways, those on collectively migrating PDACs appeared highly dependent on the PI 3-kinase pathway. Conclusion: This study strongly suggests the involvement of neurotensin in the modulation of human PDAC migration.

  16. CpG DNA assists the whole inactivated H9N2 influenza virus in crossing the intestinal epithelial barriers via transepithelial uptake of dendritic cell dendrites.

    Science.gov (United States)

    Yin, Y; Qin, T; Wang, X; Lin, J; Yu, Q; Yang, Q

    2015-07-01

    Intestinal mucosa remains a pivotal barrier for the oral vaccine absorption of H9N2 whole inactivated influenza virus (WIV). However, CpG DNA, as an adjuvant, can effectively improve relevant mucosal and systemic immunity. The downstream mechanism is well confirmed, yet the evidence of CpG DNA assisting H9N2 WIV in transepithelial delivery is lacking. Here, we reported both in vitro and in vivo that CpG DNA combined with H9N2 WIV was capable of recruiting additional dendritic cells (DCs) to the intestinal epithelial cells (ECs) to form transepithelial dendrites (TEDs) for luminal viral uptake. Both CD103(+) and CD103(-) DCs participated in this process. The engagement of the chemokine CCL20 from the apical ECs and the DCs drove DC recruitment and TED formation. Virus-loaded CD103(+) but not CD103(-) DCs also quickly migrated into mesenteric lymph nodes within 2 h. Moreover, the mechanism of CpG DNA was independent of epithelial transcytosis and disruption of the epithelial barriers. Finally, the subsequent phenotypic and functional maturation of DCs was also enhanced. Our findings indicated that CpG DNA improved the delivery of H9N2 WIV via TEDs of intestinal DCs, and this may be an important mechanism for downstream effective antigen-specific immune responses.

  17. Les questions de migrations internationales (Questions of International Migrations).

    Science.gov (United States)

    Samman, Mouna Liliane

    1993-01-01

    Education about international migration should (1) utilize a framework of historical evolution; (2) stress the growing interdependence of nations; (3) emphasize universal moral values and the role of the individual in human rights; and (4) consider the complementary or competing portraits of international migration presented by the media. (DMM)

  18. Trefoil factor 3 peptide regulates migration via a Twist-dependent pathway in gastric cell.

    Science.gov (United States)

    Zheng, Qianqian; Gao, Jian; Li, Honglin; Guo, Wendong; Mao, Qi; Gao, Enhui; Zhu, Ya-qin

    2013-08-16

    Trefoil factor 3 (TFF3) is a member of the TFF-domain peptide family and essential in regulating cell migration and maintaining mucosal integrity in gastrointestinal tract. However, the role of TFF3 and its downstream regulating mechanisms in cancer cell migration remain unclear. We previously reported that TFF3 prolonged the up-regulation of Twist protein to modulate IL-8 secretion in intestinal epithelial cells. In this study, we investigated the role of Twist protein in TFF3-induced migration of SGC7901 cells. While Twist was activated by TFF3, siRNA-mediated knockdown of Twist abolished TFF3-induced cell migration. Furthermore, the migration related marker CK-8 as well as ZO-1 and MMP-9 was also regulated by TFF3 via a Twist-dependent mechanism. Our study suggests that Twist, as an important potential downstream effector, plays a key role in TFF3-modulated metastasis in gastric cancer and can be a promising therapeutic target against intestinal-type gastric cancer.

  19. HANDICRAFTS, INVASIONS AND MIGRATIONS

    Directory of Open Access Journals (Sweden)

    Perla Shiomara del Carpio Ovando

    2014-01-01

    Full Text Available This research is focused on the migratory movements that have characterized Simojovel de Allende, Chiapas. Both indigenous Tsotsil communities as well as mestizos from different municipalities live in Simojovel, which is a town that has had multiple migratory movements due to different reasons. For example, economical struggle that has led to poverty, the lack of opportunities; the political situation, religious and ethnic persecutions, insecurity and the communitarian division between zapatistas and non-zapatistas. There are also cultural factors that have caused migration in Simojovel such as tradition, generational gaps, young people’s interests for new types of work and ways of living. Simojovel has been characterized by its coffee, tobacco and amber, but also by its migratory activity.

  20. Kirchhoff migration without phases

    Science.gov (United States)

    Bardsley, Patrick; Guevara Vasquez, Fernando

    2016-10-01

    We present a simple, frequency domain, preprocessing step to Kirchhoff migration that allows the method to image scatterers when the wave field phase information is lost at the receivers, and only intensities are measured. The resulting imaging method does not require knowing the phases of the probing field or manipulating the phase of the wave field at the receivers. In a regime where the scattered field is small compared to the probing field, the problem of recovering the full-waveform scattered field from intensity data can be formulated as an embarrassingly simple least-squares problem. Although this only recovers the projection (on a known subspace) of the full-waveform scattered field, we show that, for high frequencies, this projection gives Kirchhoff images asymptotically identical to the images obtained with full waveform data. Our method can also be used when the source is modulated by a Gaussian process and autocorrelations are measured at an array of receivers.

  1. Kirchhoff migration without phases

    CERN Document Server

    Bardsley, Patrick

    2016-01-01

    We present a simple, frequency domain, preprocessing step to Kirchhoff migration that allows the method to image scatterers when the wave field phase information is lost at the receivers, and only intensities are measured. The resulting imaging method does not require knowing the phases of the probing field or manipulating the phase of the wave field at the receivers. In a regime where the scattered field is small compared to the probing field, the problem of recovering the full-waveform scattered field from intensity data can be formulated as an embarrassingly simple least-squares problem. Although this only recovers the projection (on a known subspace) of the full-waveform scattered field, we show that, for high frequencies, this projection gives Kirchhoff images asymptotically identical to the images obtained with full waveform data. Our method can also be used when the source is modulated by a Gaussian process and autocorrelations are measured at an array of receivers.

  2. 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.

  3. Expert Group Meeting on Population Distribution and Migration.

    Science.gov (United States)

    1993-01-01

    call for appropriate policies, cooperation, protection of human rights, an end to discrimination toward women, the normalization of family life among documented migrants, the promotion of good community relations between migrants and the rest of society, the guarantee of equal economic and social rights to longterm foreign residents and facilitation of their naturalization, the provision of legal information to potential migrants, the provision of equal educational and training opportunities to the children of migrants, and the institution of sanctions against the organizers of illegal migration. The next 7 recommendations urge that the causes of forced migration be addressed, that refugees receive assistance and protection, that the responsibility for refugees be shared equitably, that the right to asylum be protected, that appropriate repatriation programs be supported, that long-standing refugee populations be helped to achieve self-sufficiency, and that the specific needs of refugee women be addressed. The final 7 recommendations cover data and research needs regarding population distribution and migration and urge support for research on population distribution, the collection of national statistics, a review of existing standard definitions and classifications of rural and urban populations and of international migration, cooperation in the registration and monitoring of refugee populations, and the promotion of an exchange of information on trends and policies of international migration.

  4. Downstream boundary effects on the frequency of self-excited oscillations in transonic diffuser flows

    Science.gov (United States)

    Hsieh, T.

    1986-10-01

    Investigation of downstream boundary effects on the frequency of self-excited oscillations in two-dimensional, separated transonic diffuser flows were conducted numerically by solving the compressible, Reynolds-averaged, thin-layer Navier-Stokes equation with two equation turbulence models. It was found that the flow fields are very sensitive to the location of the downstream boundary. Extension of the diffuser downstream boundary significantly reduces the frequency and amplitude of oscillations for pressure, velocity, and shock. The existence of a suction slot in the experimental setpup obscures the physical downstream boundary and therefore presents a difficulty for quantitative comparisons between computation and experiment.

  5. Migration and the Wage Curve:

    DEFF Research Database (Denmark)

    Brücker, Herbert; Jahn, Elke J.

      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...

  6. Africa: Setting for Human Migration

    Science.gov (United States)

    Buuba, Babacar Diop

    2007-01-01

    Analysis of African migrations can help to understand prehistoric, historical, ancient modern and contemporaneous migrations. Movements of populations were and continue to be so intense that, for some analysts, they constitute one of the dominant trends of the history and destiny of the very old continent. African and non-African states, whether…

  7. New dimensions in cell migration

    NARCIS (Netherlands)

    Friedl, P.; Sahai, E.; Weiss, S.; Yamada, K.M.

    2012-01-01

    Studies of cell migration in three-dimensional (3D) cell culture systems and in vivo have revealed several differences when compared with cell migration in two dimensions, including their morphology and mechanical and signalling control. Here, researchers assess the contribution of 3D models to our

  8. The migration of university graduates

    DEFF Research Database (Denmark)

    Drejer, Ina; Holm, Jacob Rubæk; Nielsen, Kristian

    of university graduates is an important issue for regional policy makers. The present paper analyzes the migration patterns of university graduates from two very different regions in Denmark: the Greater Capital region around Copenhagen and the peripheral region of North Denmark. Studies of the migration...

  9. Oxidative stress and its downstream signaling in aging eyes

    Directory of Open Access Journals (Sweden)

    Pinazo-Durán MD

    2014-04-01

    Full Text Available María Dolores Pinazo-Durán,1,* Roberto Gallego-Pinazo,2,* Jose Javier García-Medina,1,3,* Vicente Zanón-Moreno,1,4 Carlo Nucci,5 Rosa Dolz-Marco,2 Sebastián Martínez-Castillo,2 Carmen Galbis-Estrada,1 Carla Marco-Ramírez,1 Maria Isabel López-Gálvez,6,* David J Galarreta,6,* Manuel Díaz-Llópis4,*1Ophthalmic Research Unit "Santiago Grisolía", Valencia, Spain; 2Department of Ophthalmology, Macula Section, The University and Polytechnic Hospital La Fe, Valencia, Spain; 3Department of Ophthalmology, University Hospital Reina Sofia, Murcia, Spain; 4Faculty of Medicine, University of Valencia, Spain; 5University of Rome Tor Vergata, Rome, Italy; 6Instituto de Oftalmobiología Aplicada (IOBA, Valladolid, Spain *Members of the Spanish Net of Ocular Pathology of the Instituto de Salud Carlos III (Madrid, OFTAREDBackground: Oxidative stress (OS and its biomarkers are the biochemical end point of the imbalance between reactive oxygen species (ROS production and the ability of the antioxidant (AOX biological systems to fight against oxidative injury.Objective: We reviewed the role of OS and its downstream signaling in aging eyes.Methods: A search of the literature and current knowledge on the physiological and pathological mechanisms of OS were revisited in relation to the eyes and the aging process. Most prevalent ocular diseases have been analyzed herein in relation to OS and nutraceutic supplements, such as dry-eye disorders, glaucoma, age-related macular degeneration, and diabetic retinopathy.Results: Clinical, biochemical, and molecular data from anterior and posterior eye segment diseases point to OS as the common pathogenic mechanism in the majority of these ocular disorders, many of which are pathologies causing visual impairment, blindness, and subsequent loss of life quality. Studies with nutraceutic supplements in aging eye-related pathologies have also been reviewed.Conclusion: OS, nutritional status, and nutraceutic supplements have

  10. Data Migration for Ontology Evolution

    Institute of Scientific and Technical Information of China (English)

    赵彦; 张雷; 林晨曦; 张卓; 俞勇

    2004-01-01

    Ontology is the conceptual backbone that provides meaning to data on the semantic web. However, ontology is not a static resource and may evolve over time, which often leaves the meaning of data in an undefined or inconsistent state. It is thus very important to have a method to preserve the data and its meaning when ontology changes. This paper proposed a general method that solves the problem using data migration. It analyzed some of the issues in the method including separation of ontology and data, migration specification, migration result and migration algorithm. The paper also instantiates the general mothod in RDF(S) as an example. The RDF(S) example itself is a simple but complete method for migrating RDF data when RDFS ontology changes.

  11. Carbon nanotube-assisted optical activation of TGF-β signalling by near-infrared light

    Science.gov (United States)

    Lin, Liang; Liu, Ling; Zhao, Bing; Xie, Ran; Lin, Wei; Li, He; Li, Yaya; Shi, Minlong; Chen, Ye-Guang; Springer, Timothy A.; Chen, Xing

    2015-05-01

    Receptor-mediated signal transduction modulates complex cellular behaviours such as cell growth, migration and differentiation. Although photoactivatable proteins have emerged as a powerful tool for controlling molecular interactions and signalling cascades at precise times and spaces using light, many of these light-sensitive proteins are activated by ultraviolent or visible light, which has limited tissue penetration. Here, we report a single-walled carbon nanotube (SWCNT)-assisted approach that enables near-infrared light-triggered activation of transforming growth factor β (TGF-β) signal transduction, an important signalling pathway in embryonic development and cancer progression. The protein complex of TGF-β and its latency-associated peptide is conjugated onto SWCNTs, where TGF-β is inactive. Upon near-infrared irradiation, TGF-β is released through the photothermal effect of SWCNTs and becomes active. The released TGF-β activates downstream signal transduction in live cells and modulates cellular behaviours. Furthermore, preliminary studies show that the method can be used to mediate TGF-β signalling in living mice.

  12. 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.

  13. 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)

  14. Dynamic cell adhesion and migration on nanoscale grooved substrates.

    Science.gov (United States)

    Lamers, E; te Riet, J; Domanski, M; Luttge, R; Figdor, C G; Gardeniers, J G E; Walboomers, X F; Jansen, J A

    2012-01-01

    Organised nanotopography mimicking the natural extracellular matrix can be used to control morphology, cell motility, and differentiation. However, it is still unknown how specific cell types react with specific patterns. Both initial adhesion and preferential cell migration may be important to initiate and increase cell locomotion and coverage with cells, and thus achieve an enhanced wound healing response around an implantable material. Therefore, the aim of this study was to evaluate how MC3T3-E1 osteoblast initial adhesion and directional migration are influenced by nanogrooves with pitches ranging from 150 nm up to 1000 nm. In this study, we used a multi-patterned substrate with five different groove patterns and a smooth area with either a concentric or radial orientation. Initial cell adhesion measurements after 10 s were performed using atomic force spectroscopy-assisted single-cell force spectroscopy, and demonstrated that nascent cell adhesion was highly induced by a 600 nm pitch and reduced by a 150 nm pitch. Addition of RGD peptide significantly reduced adhesion, indicating that integrins and cell adhesive proteins (e.g. fibronectin or vitronectin) are key factors in specific cell adhesion on nanogrooved substrates. Also, cell migration was highly dependent on the groove pitch; the highest directional migration parallel to the grooves was observed on a 600 nm pitch, whereas a 150 nm pitch restrained directional cell migration. From this study, we conclude that grooves with a pitch of 600 nm may be favourable to enhance fast wound closure, thereby promoting tissue regeneration.

  15. Rab, Arf, and Arl-Regulated Membrane Traffic in Cortical Neuron Migration.

    Science.gov (United States)

    Tang, Bor Luen

    2016-07-01

    The migration of projection neurons from its birthplace in the subventricular zone to their final destination in the cortical plate is a complex process that requires a series of highly coordinated cellular events. Amongst the key factors involved in the processes are modulators of cytoskeletal dynamics, as well as cellular membrane traffic. Members of the small GTPases family responsible for the latter process, the Rabs and Arfs, have been recently implicated in cortical neuron migration. Rab5 and Rab11, which are key modulators of endocytosis and endocytic recycling respectively, ensure proper surface expression and distribution of N-cadherin, a key adhesion protein that tethers migrating neurons to the radial glia fiber tracts during pia-directed migration. Rab7, which is associated with lysosomal biogenesis and function, is important for the final step of terminal translocation when N-cadherin is downregulated by lysosomal degradation. Arf6 activity, which is known to be important in neuronal processes outgrowth, may negatively impact the multipolar-bipolar transition of cortical neurons undergoing radial migration, but the downstream effector of Arf6 in this regard is not yet known. In addition to the above, members of the Arl family which have been recently shown to be important in radial glia scaffold formation, would also be important for cortical neuron migration. In this short review, we discuss recent advances in our understanding of the importance of membrane traffic regulated by the Rab, Arf, and Arl family members in cortical neuron migration.

  16. A novel role for Lsc/p115 RhoGEF and LARG in regulating RhoA activity downstream of adhesion to fibronectin.

    Science.gov (United States)

    Dubash, Adi D; Wennerberg, Krister; García-Mata, Rafael; Menold, Marisa M; Arthur, William T; Burridge, Keith

    2007-11-15

    Adhesion of cells to extracellular matrix proteins such as fibronectin initiates signaling cascades that affect cell morphology, migration and survival. Some of these signaling pathways involve the Rho family of GTPases, such as Cdc42, Rac1 and RhoA, which play a key role in regulating the organization of the cytoskeleton. Although significant advances have been made in understanding how Rho proteins control cytoskeletal architecture, less is known about the signals controlling activation of the GTPases themselves. The focus of this study was to determine which guanine nucleotide exchange factor(s) are responsible for activation of RhoA downstream of adhesion to fibronectin. Using an affinity pulldown assay for activated exchange factors, we show that the RhoA-specific exchange factors Lsc/p115 RhoGEF and LARG are activated when cells are plated onto fibronectin, but not other exchange factors such as Ect2 or Dbl. Knockdown of Lsc and LARG together significantly decreases RhoA activation and formation of stress fibers and focal adhesions downstream of fibronectin adhesion. Similarly, overexpression of a catalytically inactive mutant of Lsc/p115 RhoGEF inhibits RhoA activity and formation of stress fibers and focal adhesions on fibronectin. These data establish a previously uncharacterized role for the exchange factors Lsc/p115 RhoGEF and LARG in linking fibronectin signals to downstream RhoA activation.

  17. 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

  18. Musei del migration heritage

    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.

  19. 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

  20. 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.

  1. Simple rules guide dragonfly migration

    Science.gov (United States)

    Wikelski, Martin; Moskowitz, David; Adelman, James S; Cochran, Jim; Wilcove, David S; May, Michael L

    2006-01-01

    Every year billions of butterflies, dragonflies, moths and other insects migrate across continents, and considerable progress has been made in understanding population-level migratory phenomena. However, little is known about destinations and strategies of individual insects. We attached miniaturized radio transmitters (ca 300 mg) to the thoraxes of 14 individual dragonflies (common green darners, Anax junius) and followed them during their autumn migration for up to 12 days, using receiver-equipped Cessna airplanes and ground teams. Green darners exhibited distinct stopover and migration days. On average, they migrated every 2.9±0.3 days, and their average net advance was 58±11 km in 6.1±0.9 days (11.9±2.8 km d−1) in a generally southward direction (186±52°). They migrated exclusively during the daytime, when wind speeds were less than 25 km h−1, regardless of wind direction, but only after two nights of successively lower temperatures (decrease of 2.1±0.6 °C in minimum temperature). The migratory patterns and apparent decision rules of green darners are strikingly similar to those proposed for songbirds, and may represent a general migration strategy for long-distance migration of organisms with high self-propelled flight speeds. PMID:17148394

  2. 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

  3. Quantitative phosphoproteomic analysis reveals system-wide signaling pathways downstream of SDF-1/CXCR4 in breast cancer stem cells.

    Science.gov (United States)

    Yi, Tingfang; Zhai, Bo; Yu, Yonghao; Kiyotsugu, Yoshikawa; Raschle, Thomas; Etzkorn, Manuel; Seo, Hee-Chan; Nagiec, Michal; Luna, Rafael E; Reinherz, Ellis L; Blenis, John; Gygi, Steven P; Wagner, Gerhard

    2014-05-27

    Breast cancer is the leading cause of cancer-related mortality in women worldwide, with an estimated 1.7 million new cases and 522,000 deaths around the world in 2012 alone. Cancer stem cells (CSCs) are essential for tumor reoccurrence and metastasis which is the major source of cancer lethality. G protein-coupled receptor chemokine (C-X-C motif) receptor 4 (CXCR4) is critical for tumor metastasis. However, stromal cell-derived factor 1 (SDF-1)/CXCR4-mediated signaling pathways in breast CSCs are largely unknown. Using isotope reductive dimethylation and large-scale MS-based quantitative phosphoproteome analysis, we examined protein phosphorylation induced by SDF-1/CXCR4 signaling in breast CSCs. We quantified more than 11,000 phosphorylation sites in 2,500 phosphoproteins. Of these phosphosites, 87% were statistically unchanged in abundance in response to SDF-1/CXCR4 stimulation. In contrast, 545 phosphosites in 266 phosphoproteins were significantly increased, whereas 113 phosphosites in 74 phosphoproteins were significantly decreased. SDF-1/CXCR4 increases phosphorylation in 60 cell migration- and invasion-related proteins, of them 43 (>70%) phosphoproteins are unrecognized. In addition, SDF-1/CXCR4 upregulates the phosphorylation of 44 previously uncharacterized kinases, 8 phosphatases, and 1 endogenous phosphatase inhibitor. Using computational approaches, we performed system-based analyses examining SDF-1/CXCR4-mediated phosphoproteome, including construction of kinase-substrate network and feedback regulation loops downstream of SDF-1/CXCR4 signaling in breast CSCs. We identified a previously unidentified SDF-1/CXCR4-PKA-MAP2K2-ERK signaling pathway and demonstrated the feedback regulation on MEK, ERK1/2, δ-catenin, and PPP1Cα in SDF-1/CXCR4 signaling in breast CSCs. This study gives a system-wide view of phosphorylation events downstream of SDF-1/CXCR4 signaling in breast CSCs, providing a resource for the study of CSC-targeted cancer therapy.

  4. UK Migration Policy and Migration from Eastern Partnership Countries

    OpenAIRE

    2013-01-01

    This paper examines UK migration policy and recent migration flows from Eastern Partnership (EaP) countries to the UK. Although inflows of migrant workers were relatively large in the mid-2000s, especially amongst Ukrainians, these have fallen following changes to UK immigration policy, especially the Seasonal Agricultural Workers Scheme and the introduction of the Points Based System. As a result, the stock of migrants from EaP countries resident in the UK is small, especially in comparison ...

  5. 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

  6. Palaearctic-African Bird Migration

    DEFF Research Database (Denmark)

    Iwajomo, Soladoye Babatola

    investigated the relationship between the timing of autumn migration and climatic variations at local and spatial scale. The first three papers focused on speciesspecific analysis. In them I described the age-specific patterns in biometrics, phenology and migration strategies as well as trends...... 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...... also molt their flight feathers at this location and intraspecific interactions are non-aggressive. The second manuscript investigates whether variations in the timing of migration of wader species at a stopover site in southeast Sweden is influence by local or regional climatic variables...

  7. Quantifying global international migration flows.

    Science.gov (United States)

    Abel, Guy J; Sander, Nikola

    2014-03-28

    Widely available data on the number of people living outside of their country of birth do not adequately capture contemporary intensities and patterns of global migration flows. We present data on bilateral flows between 196 countries from 1990 through 2010 that provide a comprehensive view of international migration flows. Our data suggest a stable intensity of global 5-year migration flows at ~0.6% of world population since 1995. In addition, the results aid the interpretation of trends and patterns of migration flows to and from individual countries by placing them in a regional or global context. We estimate the largest movements to occur between South and West Asia, from Latin to North America, and within Africa.

  8. Interregional migration flows in Indonesia

    NARCIS (Netherlands)

    Wajdi, N.; van Wissen, L.J.G.; Mulder, C.H.

    2015-01-01

    Population Census and Intercensal Population Survey data permit description of the origin–destination patterns that characterize interregional migration flows in Indonesia. Application of the framework of population redistribution proposed by Long (1985) results in indications of over-urbanization,

  9. Migration and Deforestation in Indonesia

    OpenAIRE

    Darmawan, Rivayani; Klasen, Stephan; Nuryartono, Nunung

    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 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 relationship between migration and deforestation. Migration may contribute to the forest cover change, as migra...

  10. Homeward bound: Yemeni return migration.

    Science.gov (United States)

    Colton, N A

    1993-01-01

    The author discusses the return migration of Yemenis from Saudi Arabia during the period 1970-1989. "Through the use of original, empirical data collected in Yemen, this article sheds light on who these returning migrants are, where they have come from, and what sort of future awaits them.... The survey conducted on return migration was administered in the winter and spring of 1989 in a region of North Yemen called al-Hujariyya."

  11. articles: Describing migration spatial structure

    OpenAIRE

    Andrei Rogers; Frans Willekens; James Raymer; Jani Little

    2002-01-01

    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 definition in this article, one that draws on the log-linear specification of the geographer's spatial interaction model. We illustrate our definition with observed migration data, we discuss extens...

  12. Integrated modeling of European migration

    OpenAIRE

    Raymer, James; Wiśniowski, Arkadiusz; Forster, Jonathan J.; Peter W. F. Smith; Bijak, Jakub

    2013-01-01

    International migration data in Europe are collected by individual countries with separate collection systems and designs. As a result, reported data are inconsistent in availability, definition and quality. In this paper, we propose a Bayesian model to overcome the limitations of the various data sources. The focus is on estimating recent international migration flows amongst 31 countries in the European Union and European Free Trade Association from 2002 to 2008, using data collated by Euro...

  13. Simple rules guide dragonfly migration

    OpenAIRE

    Wikelski, Martin; Moskowitz, David; Adelman, James S; Cochran, Jim; Wilcove, David S; May, Michael L

    2006-01-01

    Every year billions of butterflies, dragonflies, moths and other insects migrate across continents, and considerable progress has been made in understanding population-level migratory phenomena. However, little is known about destinations and strategies of individual insects. We attached miniaturized radio transmitters (ca 300 mg) to the thoraxes of 14 individual dragonflies (common green darners, Anax junius) and followed them during their autumn migration for up to 12 days, using receiver-e...

  14. European Integration and Labour Migration

    Directory of Open Access Journals (Sweden)

    Julda Kielyte

    2010-11-01

    Full Text Available The present paper studies how European integration might affect the migration of workers in the enlarged EU. Unlike the reduced-form migration models, we base our empirical analysis on the theory of economic geography à la Krugman (1991, which provides an alternative modelling of migration pull and push factors. Parameters of the theoretical model are estimated econometrically using historical migration data. Our empirical findings suggest that European integration would trigger selective migration between the countries in the enlarged EU. In the Baltics, Lithuania would gain about 7.25% of the total work force. In the Visegrád Four, the share of the mobile labour force would increase the most in Hungary, 8.35%, compared to the pre-integration state. Our predictions for the East-West migration are moderate and lower than those of reduced-form models: between 5.44% (from the Baltics and 3.61% (from the Visegrád Four would emigrate to the EU North. Because migrants not only follow market potential, but also shape the region’s market potential, the long-run agglomeration forces are sufficiently weak to make a swift emergence of a core-periphery pattern in the enlarged EU very unlikely.

  15. Hypoxia promotes Rab5 activation, leading to tumor cell migration, invasion and metastasis.

    Science.gov (United States)

    Silva, Patricio; Mendoza, Pablo; Rivas, Solange; Díaz, Jorge; Moraga, Carolina; Quest, Andrew F G; Torres, Vicente A

    2016-05-17

    Hypoxia, a common condition of the tumor microenvironment, is associated with poor patient prognosis, tumor cell migration, invasion and metastasis. Recent evidence suggests that hypoxia alters endosome dynamics in tumor cells, leading to augmented cell proliferation and migration and this is particularly relevant, because endosomal components have been shown to be deregulated in cancer. The early endosome protein Rab5 is a small GTPase that promotes integrin trafficking, focal adhesion turnover, Rac1 activation, tumor cell migration and invasion. However, the role of Rab5 and downstream events in hypoxia remain unknown. Here, we identify Rab5 as a critical player in hypoxia-driven tumor cell migration, invasion and metastasis. Exposure of A549 human lung carcinoma, ZR-75, MDA-MB-231 and MCF-7 human breast cancer and B16-F10 mouse melanoma cells to hypoxia increased Rab5 activation, followed by its re-localization to the leading edge and association with focal adhesions. Importantly, Rab5 was required for hypoxia-driven cell migration, FAK phosphorylation and Rac1 activation, as shown by shRNA-targeting and transfection assays with Rab5 mutants. Intriguingly, the effect of hypoxia on both Rab5 activity and migration was substantially higher in metastatic B16-F10 cells than in poorly invasive B16-F0 cells. Furthermore, exogenous expression of Rab5 in B16-F0 cells predisposed to hypoxia-induced migration, whereas expression of the inactive mutant Rab5/S34N prevented the migration of B16-F10 cells induced by hypoxia. Finally, using an in vivo syngenic C57BL/6 mouse model, Rab5 expression was shown to be required for hypoxia-induced metastasis. In summary, these findings identify Rab5 as a key mediator of hypoxia-induced tumor cell migration, invasion and metastasis.

  16. 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.

  17. Acoustic telemetry reveals large-scale migration patterns of walleye in Lake Huron.

    Directory of Open Access Journals (Sweden)

    Todd A Hayden

    Full Text Available Fish migration in large freshwater lacustrine systems such as the Laurentian Great Lakes is not well understood. The walleye (Sander vitreus is an economically and ecologically important native fish species throughout the Great Lakes. In Lake Huron walleye has recently undergone a population expansion as a result of recovery of the primary stock, stemming from changing food web dynamics. During 2011 and 2012, we used acoustic telemetry to document the timing and spatial scale of walleye migration in Lake Huron and Saginaw Bay. Spawning walleye (n = 199 collected from a tributary of Saginaw Bay were implanted with acoustic tags and their migrations were documented using acoustic receivers (n = 140 deployed throughout U.S. nearshore waters of Lake Huron. Three migration pathways were described using multistate mark-recapture models. Models were evaluated using the Akaike Information Criterion. Fish sex did not influence migratory behavior but did affect migration rate and walleye were detected on all acoustic receiver lines. Most (95% tagged fish migrated downstream from the riverine tagging and release location to Saginaw Bay, and 37% of these fish emigrated from Saginaw Bay into Lake Huron. Remarkably, 8% of walleye that emigrated from Saginaw Bay were detected at the acoustic receiver line located farthest from the release location more than 350 km away. Most (64% walleye returned to the Saginaw River in 2012, presumably for spawning. Our findings reveal that fish from this stock use virtually the entirety of U.S. nearshore waters of Lake Huron.

  18. Kinematic artifacts in prestack depth migration.

    NARCIS (Netherlands)

    Stolk, C.C.; Symes, W.W.

    2004-01-01

    Strong refraction of waves in the migration velocity model introduces kinematic artifacts¿coherent events not corresponding to actual reflectors¿into the image volumes produced by prestack depth migration applied to individual data bins. Because individual bins are migrated independently, the migrat

  19. Distance and Intrastate College Student Migration

    Science.gov (United States)

    Alm, James; Winters, John V.

    2009-01-01

    Most studies of student migration focus on "interstate" migration of college students, largely because the aggregate data typically used are limited in geographic specificity to states. However, interstate migration is only a small part of the total student migration. Public institutions generally get most of their students from within their…

  20. Distance and Intrastate College Student Migration

    Science.gov (United States)

    Alm, James; Winters, John V.

    2009-01-01

    Most studies of student migration focus on "interstate" migration of college students, largely because the aggregate data typically used are limited in geographic specificity to states. However, interstate migration is only a small part of the total student migration. Public institutions generally get most of their students from within…

  1. Antibiotic resistance in Aeromonas upstream and downstream of a water resource recovery facility.

    Science.gov (United States)

    Cisar, Cindy R; Henderson, Samantha K; Askew, Maegan L; Risenhoover, Hollie G; McAndrews, Chrystle R; Kennedy, S Dawn; Paine, C Sue

    2014-09-01

    Aeromonas strains isolated from sediments upstream and downstream of a water resource recovery facility (WRRF) over a two-year time period were tested for susceptibility to 13 antibiotics. Incidence of resistance to antibiotics, antibiotic resistance phenotypes, and diversity (based on resistance phenotypes) were compared in the two populations. At the beginning of the study, the upstream and downstream Aeromonas populations were different for incidence of antibiotic resistance (p resistance phenotypes (p antibiotic resistance in Aeromonas in stream sediments fluctuates considerably over time and (2) suggest that WRRF effluent does not, when examined over the long- term, affect antibiotic resistance in Aeromonas in downstream sediment.

  2. 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.

  3. The Interaction of Adrenomedullin and Macrophages Induces Ovarian Cancer Cell Migration via Activation of RhoA Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Xiaoyan Pang

    2013-01-01

    Full Text Available Tumor-associated macrophages (TAMs are correlated with poor prognosis in many human cancers; however, the mechanism by which TAMs facilitate ovarian cancer cell migration and invasion remains unknown. This study was aimed to examine the function of adrenomedullin (ADM in macrophage polarization and their further effects on the migration of ovarian cancer cells. Exogenous ADM antagonist and small interfering RNA (siRNA specific for ADM expression were treated to macrophages and EOC cell line HO8910, respectively. Then macrophages were cocultured with HO8910 cells without direct contact. Flow cytometry, Western blot and real-time PCR were used to detect macrophage phenotype and cytokine production. The migration ability and cytoskeleton rearrangement of ovarian cancer cells were determined by Transwell migration assay and phalloidin staining. Western blot was performed to evaluate the activity status of signaling molecules in the process of ovarian cancer cell migration. The results showed that ADM induced macrophage phenotype and cytokine production similar to TAMs. Macrophages polarized by ADM promoted the migration and cytoskeleton rearrangement of HO8910 cells. The expression of RhoA and its downstream effector, cofilin, were upregulated in macrophage-induced migration of HO8910 cells. In conclusion, ADM could polarize macrophages similar to TAMs, and then polarized macrophages promote the migration of ovarian cancer cells via activation of RhoA signaling pathway in vitro.

  4. Migration and sustainability - compatible or contradictory?

    DEFF Research Database (Denmark)

    Røpke, Inge

    2006-01-01

    When the migration issue is discussed in a sustainability perspective, two questions are vital: 1) What is the relationship between migration and the global population growth? 2) What is the relationship between migration and consumption growth, and how does migration influence the distribution o...... of consumption possibilities both between and within industrialized and developing countries? Based on responses to these questions, it is argued that reasonably managed migration will be compatible with sustainable development....

  5. International migration in Serbia: Facts and policies

    OpenAIRE

    Bobić Mirjana; Babović Marija

    2013-01-01

    In the absence of comprehensive, systematic and precize data on international migration in Serbia, and consequently the analysis of migration trends, their drivers and outcomes, the objective of this paper is to offer the review of contemporary migration flows in Serbia. International migration flows are observed in the context of semi-peripheral position of Serbia in the global system, and hindered transformation and development. Migrations are analyzed at the macro level, according to...

  6. Cell migration in confined environments.

    Science.gov (United States)

    Irimia, Daniel

    2014-01-01

    We describe a protocol for measuring the speed of human neutrophils migrating through small channels, in conditions of mechanical confinement comparable to those experienced by neutrophils migrating through tissues. In such conditions, we find that neutrophils move persistently, at constant speed for tens of minutes, enabling precise measurements at single cells resolution, for large number of cells. The protocol relies on microfluidic devices with small channels in which a solution of chemoattractant and a suspension of isolated neutrophils are loaded in sequence. The migration of neutrophils can be observed for several hours, starting within minutes after loading the neutrophils in the devices. The protocol is divided into four main steps: the fabrication of the microfluidic devices, the separation of neutrophils from whole blood, the preparation of the assay and cell loading, and the analysis of data. We discuss the practical steps for the implementation of the migration assays in biology labs, the adaptation of the protocols to various cell types, including cancer cells, and the supplementary device features required for precise measurements of directionality and persistence during migration.

  7. 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

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

    Science.gov (United States)

    2010-11-01

    ... HOUSE, WASHINGTON, August 26, 2010 [FR Doc. 2010-27672 Filed 10-29-10; 8:45 am] Billing code 4710-10-P ... Documents#0;#0; ] Presidential Determination No. 2011-12 of August 26, 2010 Unexpected Urgent Refugee and...) of the Migration and Refugee Assistance Act of 1962 (the ``Act''), as amended (22 U.S.C....

  9. 75 FR 67015 - Unexpected Urgent Refugee And Migration Needs Resulting From Flooding InPakistan

    Science.gov (United States)

    2010-11-01

    ....) THE WHITE HOUSE, WASHINGTON, September 3, 2010 [FR Doc. 2010-27673 Filed 10-29-10; 8:45 am] Billing... Documents#0;#0; ] Presidential Determination No. 2011-14 of September 3, 2010 Unexpected Urgent Refugee And...) of the Migration and Refugee Assistance Act of 1962 (the ``Act''), as amended (22 U.S.C....

  10. 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 Rus

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

    NARCIS (Netherlands)

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

    2004-01-01

    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 Ru

  12. 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.

  13. Theory and observations of Ekman flux in the chlorophyll distribution downstream of South Georgia.

    OpenAIRE

    Venables, Hugh; Meredith, Michael Paul

    2009-01-01

    A large phytoplankton bloom occurs downstream of South Georgia, an island on the northern edge of the Scotia Sea, Atlantic sector of the Southern Ocean. This is due to natural iron fertilisation being advected downstream in the Antarctic Circumpolar Current. Mapping of SeaWiFS chl-a in dynamic height/longitude space reveals the trajectory of surface water under the dual influences of geostrophic flow and Ekman flux. A theoretical estimate of the trajectory shows good agreement with observatio...

  14. Development of an idealised downstream cyclone: Eulerian and Lagrangian perspective on the kinetic energy

    OpenAIRE

    Papritz, Lukas; Schemm, Sebastian

    2013-01-01

    In this idealised modelling study, the development of a downstream cyclone, which closely follows the life-cycle of a Shapiro-Keyser cyclone, is addressed from a quasi-geostrophic kinetic energy perspective. To this end a simulation of a dry, highly idealised, dispersive baroclinic wave, developing a primary and a downstream cyclone, is performed. Kinetic energy and processes contributing to its tendency – in particular baroclinic conversion and ageostrophic geopotential fluxes – are investig...

  15. User experience network. Erroneous downstream occlusion alarms may disable Smiths Medical CADD-Solis infusion pumps.

    Science.gov (United States)

    2010-10-01

    Due to an issue in manufacturing, downstream occlusion (DSO) sensors in some Smiths Medical CADD-Solis infusion pumps may drift out of calibration, potentially resulting in erroneous alarms that disable the units. Hospitals experiencing the problem should return affected units to Smiths Medical for recalibration (free of charge) and should consider testing all their CADD-Solis pumps during routine maintenance to ensure that they alarm appropriately for downstream occlusions.

  16. Brownian Motion in Planetary Migration

    CERN Document Server

    Murray-Clay, R A; Murray-Clay, Ruth A.; Chiang, Eugene I.

    2006-01-01

    A residual planetesimal disk of mass 10-100 Earth masses remained in the outer solar system following the birth of the giant planets, as implied by the existence of the Oort cloud, coagulation requirements for Pluto, and inefficiencies in planet formation. Upon gravitationally scattering planetesimal debris, planets migrate. Orbital migration can lead to resonance capture, as evidenced here in the Kuiper and asteroid belts, and abroad in extra-solar systems. Finite sizes of planetesimals render migration stochastic ("noisy"). At fixed disk mass, larger (fewer) planetesimals generate more noise. Extreme noise defeats resonance capture. We employ order-of-magnitude physics to construct an analytic theory for how a planet's orbital semi-major axis fluctuates in response to random planetesimal scatterings. To retain a body in resonance, the planet's semi-major axis must not random walk a distance greater than the resonant libration width. We translate this criterion into an analytic formula for the retention effi...

  17. Planet migration and magnetic torques

    Science.gov (United States)

    Strugarek, A.; Brun, A. S.; Matt, S. P.; Reville, V.

    2016-10-01

    The possibility that magnetic torques may participate in close-in planet migration has recently been postulated. We develop three dimensional global models of magnetic star-planet interaction under the ideal magnetohydrodynamic (MHD) approximation to explore the impact of magnetic topology on the development of magnetic torques. We conduct twin numerical experiments in which only the magnetic topology of the interaction is altered. We find that magnetic torques can vary by roughly an order of magnitude when varying the magnetic topology from an aligned case to an anti-aligned case. Provided that the stellar magnetic field is strong enough, we find that magnetic migration time scales can be as fast as ~100 Myr. Hence, our model supports the idea that magnetic torques may participate in planet migration for some close-in star-planet systems.

  18. The International-Migration Network

    CERN Document Server

    Fagiolo, Giorgio

    2012-01-01

    This paper studies international migration from a complex-network perspective. We define the international-migration network (IMN) as the weighted-directed graph where nodes are world countries and links account for the stock of migrants originated in a given country and living in another country at a given point in time. We characterize the binary and weighted architecture of the network and its evolution over time in the period 1960-2000. We find that the IMN is organized around a modular structure characterized by a small-world pattern displaying disassortativity and high clustering, with power-law distributed weighted-network statistics. We also show that a parsimonious gravity model of migration can account for most of observed IMN topological structure. Overall, our results suggest that socio-economic, geographical and political factors are more important than local-network properties in shaping the structure of the IMN.

  19. 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....

  20. Rural migration in southern Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Mosser, D.; Soden, D.L.

    1993-08-01

    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.

  1. 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...

  2. Full wavefield migration: utilization of multiples in seismic migration

    NARCIS (Netherlands)

    Berkhout, A.J.; Verschuur, D.J.

    2012-01-01

    The next generation migration technology considers multiple scattering as vital information, allowing the industry to generate significantly better images of the subsurface. The proposed full wavefield algorithm (FWM) makes use of two-way wave theory that is formulated in terms of one-way wavefields

  3. [International migration in the Americas: intraregional migration grows].

    Science.gov (United States)

    Zlotnik, H

    1992-01-01

    The principal destinations for intraregional migrants in South America in recent decades have been Argentina, Brazil, and Venezuela, while in North America the U.S. has exerted a growing attraction since 1965. Intraregional migration in Latin America has been irregular and difficult to quantify, and reliable statistics on migratory flows are nonexistent. Census data indicate that most migration to Argentina and Brazil occurred before 1960, while most migration to Venezuela occurred during the 1970s. Between 1960 and 1980, the proportion of migrants from other Latin American countries showed a tendency to increase, despite decreases in the overall level of immigration. The effect of the economic crisis of the 1980s on immigration from Latin American countries will become more apparent as census data for the 1990s become available. Selectivity according to country of origin is an important characteristic of intraregional migration in South America. The U.S. has, however, been the principal destination of Latin American migrants for the past three decades. Between 1965 and 1991 the U.S. granted resident status to more than 7.4 million persons of Latin American and Caribbean origin, and they constituted 47% of immigrants during those years. The great majority of the Latin American immigrants in the U.S. are Mexican. The 3.5 million Mexicans admitted to the U.S. as immigrants between 1965 and 1991 accounted for 22% of all immigrants during this period.

  4. DNA Damage Follows Repair Factor Depletion and Portends Genome Variation in Cancer Cells after Pore Migration.

    Science.gov (United States)

    Irianto, Jerome; Xia, Yuntao; Pfeifer, Charlotte R; Athirasala, Avathamsa; Ji, Jiazheng; Alvey, Cory; Tewari, Manu; Bennett, Rachel R; Harding, Shane M; Liu, Andrea J; Greenberg, Roger A; Discher, Dennis E

    2017-01-23

    Migration through micron-size constrictions has been seen to rupture the nucleus, release nuclear-localized GFP, and cause localized accumulations of ectopic 53BP1-a DNA repair protein. Here, constricted migration of two human cancer cell types and primary mesenchymal stem cells (MSCs) increases DNA breaks throughout the nucleoplasm as assessed by endogenous damage markers and by electrophoretic "comet" measurements. Migration also causes multiple DNA repair proteins to segregate away from DNA, with cytoplasmic mis-localization sustained for many hours as is relevant to delayed repair. Partial knockdown of repair factors that also regulate chromosome copy numbers is seen to increase DNA breaks in U2OS osteosarcoma cells without affecting migration and with nucleoplasmic patterns of damage similar to constricted migration. Such depletion also causes aberrant levels of DNA. Migration-induced nuclear damage is nonetheless reversible for wild-type and sub-cloned U2OS cells, except for lasting genomic differences between stable clones as revealed by DNA arrays and sequencing. Gains and losses of hundreds of megabases in many chromosomes are typical of the changes and heterogeneity in bone cancer. Phenotypic differences that arise from constricted migration of U2OS clones are further illustrated by a clone with a highly elongated and stable MSC-like shape that depends on microtubule assembly downstream of the transcription factor GATA4. Such changes are consistent with reversion to a more stem-like state upstream of cancerous osteoblastic cells. Migration-induced genomic instability can thus associate with heritable changes.

  5. 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

  6. [Family reunification, family-formation migration, and return migration of Turks and Moroccans].

    Science.gov (United States)

    De Beer, J; Kuijper, H; Noordam, R

    1991-01-01

    The authors analyze migration patterns to the Netherlands from Turkey and Morocco for the period 1977-1989. Three distinct phases emerge: labor migration, family-reunification migration, and family-formation migration. The rise in migration from Turkey and Morocco during the second half of the 1980s is attributed to family-formation migration, which is defined as a member of the second generation marrying a partner from the country of origin. (SUMMARY IN ENG)

  7. Dynamics of prey moving through a predator field: a model of migrating juvenile salmon

    Science.gov (United States)

    Petersen, J.H.; DeAngelis, D.L.

    2000-01-01

    The migration of a patch of prey through a field of relatively stationary predators is a situation that occurs frequently in nature. Making quantitative predictions concerning such phenomena may be difficult, however, because factors such as the number of the prey in the patch, the spatial length and velocity of the patch, and the feeding rate and satiation of the predators all interact in a complex way. However, such problems are of great practical importance in many management situations; e.g., calculating the mortality of juvenile salmon (smolts) swimming down a river or reservoir containing many predators. Salmon smolts often move downstream in patches short compared with the length of the reservoir. To take into account the spatial dependence of the interaction, we used a spatially-explicit, individual-based modeling approach. We found that the mortality of prey depends strongly on the number of prey in the patch, the downstream velocity of prey in the patch, and the dispersion or spread of the patch in size through time. Some counterintuitive phenomena are predicted, such as predators downstrean capturing more prey per predator than those upstream, even though the number of prey may be greatly depleted by the time the prey patch reaches the downstream predators. Individual-based models may be necessary for complex spatial situations, such as salmonid migration, where processes such as schooling occur at fine scales and affect system predictions. We compare some results to predictions from other salmonid models. (C) 2000 Elsevier Science Inc.

  8. Migration of red-backed shrikes from the Iberian Peninsula: optimal or sub-optimal detour?

    DEFF Research Database (Denmark)

    Tøttrup, Anders P.; Pedersen, Lykke; Onrubia, Alejandro;

    2017-01-01

    e current Northern Hemisphere migration systems are believed to have arisen since the last glaciation. In many cases, birds do not migrate strait from breeding to non-breeding areas but fly via a detour. All western European populations of red-backed shrikes Lanius collurio are assumed to reach...... their southern African wintering grounds detouring via southeast Europe. Based on theoretical considerations under an optimality framework this detour is apparently optimal. Here, we use individual geolocator data on red-backed shrikes breeding in Spain to show that these birds do indeed detour via southeast...... migration the situation was quite different with the detour apparently being optimal. However, when considering potential wind assistance estimated total air distances during autumn migration were overall similar and the barrier crossing shorter along the observed routes. We conclude that considering...

  9. Migration cost externality and interregional equilibrium.

    Science.gov (United States)

    Shin, C

    1994-01-01

    "This paper will investigate the characteristics of population allocation between two regions in the presence of migration cost. It will also examine both populations and the non-migration range of the initial population in which migration does not occur, in social optimum and market equilibrium with central government intervention, to reveal migration cost externality, and to propose a remedy for it." The author finds that "migration cost gives the social planner an additional burden of population reallocation, and it has an important effect upon an individual's decisions on migration in a decentralized market mechanism."

  10. Basin-scale phenology and effects of climate variability on global timing of initial seaward migration of Atlantic salmon (Salmo salar).

    Science.gov (United States)

    Otero, Jaime; L'Abée-Lund, Jan Henning; Castro-Santos, Ted; Leonardsson, Kjell; Storvik, Geir O; Jonsson, Bror; Dempson, Brian; Russell, Ian C; Jensen, Arne J; Baglinière, Jean-Luc; Dionne, Mélanie; Armstrong, John D; Romakkaniemi, Atso; Letcher, Benjamin H; Kocik, John F; Erkinaro, Jaakko; Poole, Russell; Rogan, Ger; Lundqvist, Hans; Maclean, Julian C; Jokikokko, Erkki; Arnekleiv, Jo Vegar; Kennedy, Richard J; Niemelä, Eero; Caballero, Pablo; Music, Paul A; Antonsson, Thorolfur; Gudjonsson, Sigurdur; Veselov, Alexey E; Lamberg, Anders; Groom, Steve; Taylor, Benjamin H; Taberner, Malcolm; Dillane, Mary; Arnason, Fridthjofur; Horton, Gregg; Hvidsten, Nils A; Jonsson, Ingi R; Jonsson, Nina; McKelvey, Simon; Naesje, Tor F; Skaala, Oystein; Smith, Gordon W; Saegrov, Harald; Stenseth, Nils C; Vøllestad, Leif Asbjørn

    2014-01-01

    Migrations between different habitats are key events in the lives of many organisms. Such movements involve annually recurring travel over long distances usually triggered by seasonal changes in the environment. Often, the migration is associated with travel to or from reproduction areas to regions of growth. Young anadromous Atlantic salmon (Salmo salar) emigrate from freshwater nursery areas during spring and early summer to feed and grow in the North Atlantic Ocean. The transition from the freshwater ('parr') stage to the migratory stage where they descend streams and enter salt water ('smolt') is characterized by morphological, physiological and behavioural changes where the timing of this parr-smolt transition is cued by photoperiod and water temperature. Environmental conditions in the freshwater habitat control the downstream migration and contribute to within- and among-river variation in migratory timing. Moreover, the timing of the freshwater emigration has likely evolved to meet environmental conditions in the ocean as these affect growth and survival of the post-smolts. Using generalized additive mixed-effects modelling, we analysed spatio-temporal variations in the dates of downstream smolt migration in 67 rivers throughout the North Atlantic during the last five decades and found that migrations were earlier in populations in the east than the west. After accounting for this spatial effect, the initiation of the downstream migration among rivers was positively associated with freshwater temperatures, up to about 10 °C and levelling off at higher values, and with sea-surface temperatures. Earlier migration occurred when river discharge levels were low but increasing. On average, the initiation of the smolt seaward migration has occurred 2.5 days earlier per decade throughout the basin of the North Atlantic. This shift in phenology matches changes in air, river, and ocean temperatures, suggesting that Atlantic salmon emigration is responding to the

  11. 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.

  12. A Discrete Cell Migration Model

    Energy Technology Data Exchange (ETDEWEB)

    Nutaro, James J [ORNL; Kruse, Kara L [ORNL; Ward, Richard C [ORNL; O' Quinn, Elizabeth [Wofford College; Woerner, Matthew M [ORNL; Beckerman, Barbara G [ORNL

    2007-01-01

    Migration of vascular smooth muscle cells is a fundamental process in the development of intimal hyperplasia, a precursor to development of cardiovascular disease and a potential response to injury of an arterial wall. Boyden chamber experiments are used to quantify the motion of cell populations in response to a chemoattractant gradient (i.e., cell chemotaxis). We are developing a mathematical model of cell migration within the Boyden chamber, while simultaneously conducting experiments to obtain parameter values for the migration process. In the future, the model and parameters will be used as building blocks for a detailed model of the process that causes intimal hyperplasia. The cell migration model presented in this paper is based on the notion of a cell as a moving sensor that responds to an evolving chemoattractant gradient. We compare the results of our three-dimensional hybrid model with results from a one-dimensional continuum model. Some preliminary experimental data that is being used to refine the model is also presented.

  13. Vortex migration in protoplanetary disks

    CERN Document Server

    Paardekooper, S -J; Papaloizou, J C B

    2010-01-01

    We consider the radial migration of vortices in two-dimensional isothermal gaseous disks. We find that a vortex core, orbiting at the local gas velocity, induces velocity perturbations that propagate away from the vortex as density waves. The resulting spiral wave pattern is reminiscent of an embedded planet. There are two main causes for asymmetries in these wakes: geometrical effects tend to favor the outer wave, while a radial vortensity gradient leads to an asymmetric vortex core, which favors the wave at the side that has the lowest density. In the case of asymmetric waves, which we always find except for a disk of constant pressure, there is a net exchange of angular momentum between the vortex and the surrounding disk, which leads to orbital migration of the vortex. Numerical hydrodynamical simulations show that this migration can be very rapid, on a time scale of a few thousand orbits, for vortices with a size comparable to the scale height of the disk. We discuss the possible effects of vortex migrat...

  14. Externality, migration, and urban crises.

    Science.gov (United States)

    Kanemoto, Y

    1980-01-01

    The author analyzes a special aspect of the short-run dynamics of an urban area which arises when there is a contrast between different types of households. The possibility of cumulative or catastrophic processes because of migration by poor families and then by rich families in or out of an urban area is discussed

  15. [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.

  16. Essays on growth and migration

    NARCIS (Netherlands)

    Stryszowski, P.K.

    2009-01-01

    Essays on Growth and Migration is a collection of papers that analyze how two particular factors, the brain drain and the intellectual property rights (IPR), affect the economic performance of a given country. The theoretical models are constructed and illustrative empirical examples are provided in

  17. [Moroccan international migration: recent trends].

    Science.gov (United States)

    Lazaar, M

    1995-01-01

    Recent trends in emigration from Morocco are analyzed. The author describes the policies developed by the Moroccan government regarding emigration and the changing characteristics of the emigrants, as emigrants are becoming younger and are increasingly female. The author concludes that the increasing demand for migrant labor in Europe will result in increased emigration despite the development of restrictive migration policies.

  18. Planetary migration in protoplanetary disks

    CERN Document Server

    Popolo, A D

    2003-01-01

    In the current paper, we further develop the model for the migration of planets introduced in Del Popolo et al. (2001) and extended to time-dependent accretion discs in Del Popolo and Eksi (2002). We use a method developed by Stepinski and Valageas (1996, 1997), that is able to simultaneously follow the evolution of gas and solid particles for up to $10^7 {\\rm yr}$. The disc model is coupled to the migration model introduced in Del Popolo et al. (2001) in order to obtain the migration rate of the planet in the planetesimal disc. We find that in the case of discs having total mass of $10^{-3}-0.1 M_{\\odot}$, and $0.1<\\alpha<0.0001$, planets can migrate inward a large distance while if $M<10^{-3} M_{\\odot}$ the planets remain almost in their initial position for $0.1<\\alpha<0.01$ and only in the case $\\alpha<0.001$ the planets move to a minimum value of orbital radius of $\\simeq 2 {\\rm AU}$. The model gives a good description of the observed distribution of planets in the period range 0-20 day...

  19. 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 the

  20. 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…

  1. Dynamic cell adhesion and migration on nanoscale grooved substrates

    Directory of Open Access Journals (Sweden)

    E Lamers

    2012-03-01

    Full Text Available Organised nanotopography mimicking the natural extracellular matrix can be used to control morphology, cell motility, and differentiation. However, it is still unknown how specific cell types react with specific patterns. Both initial adhesion and preferential cell migration may be important to initiate and increase cell locomotion and coverage with cells, and thus achieve an enhanced wound healing response around an implantable material. Therefore, the aim of this study was to evaluate how MC3T3-E1 osteoblast initial adhesion and directional migration are influenced by nanogrooves with pitches ranging from 150 nm up to 1000 nm. In this study, we used a multi-patterned substrate with five different groove patterns and a smooth area with either a concentric or radial orientation. Initial cell adhesion measurements after 10 s were performed using atomic force spectroscopy-assisted single-cell force spectroscopy, and demonstrated that nascent cell adhesion was highly induced by a 600 nm pitch and reduced by a 150 nm pitch. Addition of RGD peptide significantly reduced adhesion, indicating that integrins and cell adhesive proteins (e.g. fibronectin or vitronectin are key factors in specific cell adhesion on nanogrooved substrates. Also, cell migration was highly dependent on the groove pitch; the highest directional migration parallel to the grooves was observed on a 600 nm pitch, whereas a 150 nm pitch restrained directional cell migration. From this study, we conclude that grooves with a pitch of 600 nm may be favourable to enhance fast wound closure, thereby promoting tissue regeneration.

  2. [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

  3. ForeignAssistance.gov

    Data.gov (United States)

    US Agency for International Development — ForeignAssistance.gov provides a view of U.S. Government foreign assistance funds across agencies and enables users to explore, analyze, and review aid investments...

  4. Inertial Particle Migration in the Presence of a Permeate Flow

    Science.gov (United States)

    Garcia, Mike; Singelton, Amanda; Pennathur, Sumita

    2016-11-01

    Tangential Flow Filtration (TFF) is a rapid and efficient method for the filtration and separation of suspensions of particles such as viruses, bacteria or cellular material. Enhancing the efficacy of TFF not only requires a detailed understanding of particle transport mechanisms, but also the interactions between these mechanisms and a porous wall. In this work, we numerically and experimentally explore the mechanisms of inertial particle migration in the presence of a permeate flow through the porous walls of a microchannel. Numerically, we develop a force balance model to understand the competition between permeate and inertial forces and the resultant consequences on the particle equilibrium location. Experimentally, we fabricated MEMS TFF devices to study the migration of 5, 10 and 15 µm fluorescent polystyrene beads in straight channels with perpendicular permeate flow rates up to 90% of the inlet flow rate. We find that the permeate flow directly influences the inertial focusing position of the particles, both as a function of downstream channel position and ratio of inlet to outlet flow rate. Comparing experiments to our model, we can identify inertial, viscous and a co-dominant regimes.

  5. 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

  6. Predicted molecular signaling guiding photoreceptor cell migration following transplantation into damaged retina

    Science.gov (United States)

    Unachukwu, Uchenna John; Warren, Alice; Li, Ze; Mishra, Shawn; Zhou, Jing; Sauane, Moira; Lim, Hyungsik; Vazquez, Maribel; Redenti, Stephen

    2016-03-01

    To replace photoreceptors lost to disease or trauma and restore vision, laboratories around the world are investigating photoreceptor replacement strategies using subretinal transplantation of photoreceptor precursor cells (PPCs) and retinal progenitor cells (RPCs). Significant obstacles to advancement of photoreceptor cell-replacement include low migration rates of transplanted cells into host retina and an absence of data describing chemotactic signaling guiding migration of transplanted cells in the damaged retinal microenvironment. To elucidate chemotactic signaling guiding transplanted cell migration, bioinformatics modeling of PPC transplantation into light-damaged retina was performed. The bioinformatics modeling analyzed whole-genome expression data and matched PPC chemotactic cell-surface receptors to cognate ligands expressed in the light-damaged retinal microenvironment. A library of significantly predicted chemotactic ligand-receptor pairs, as well as downstream signaling networks was generated. PPC and RPC migration in microfluidic ligand gradients were analyzed using a highly predicted ligand-receptor pair, SDF-1α - CXCR4, and both PPCs and RPCs exhibited significant chemotaxis. This work present a systems level model and begins to elucidate molecular mechanisms involved in PPC and RPC migration within the damaged retinal microenvironment.

  7. 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

  8. Downstream Intensification Effects Associated with CO2 Laser Mitigation of Fused Silica

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, M J; Bass, I L; Guss, G M; Widmayer, C C; Ravizza, F L

    2007-10-29

    Mitigation of 351nm laser-induced damage sites on fused silica exit surfaces by selective CO{sub 2} treatment has been shown to effectively arrest the exponential growth responsible for limiting the lifetime of optics in high-fluence laser systems. However, the perturbation to the optical surface profile following the mitigation process introduces phase contrast to the beam, causing some amount of downstream intensification with the potential to damage downstream optics. Control of the laser treatment process and measurement of the associated phase modulation is essential to preventing downstream 'fratricide' in damage-mitigated optical systems. In this work we present measurements of the surface morphology, intensification patterns and damage associated with various CO{sub 2} mitigation treatments on fused silica surfaces. Specifically, two components of intensification pattern, one on-axis and another off-axis can lead to damage of downstream optics and are related to rims around the ablation pit left from the mitigation process. It is shown that control of the rim structure around the edge of typical mitigation sites is crucial in preventing damage to downstream optics.

  9. Influence of Downstream Flow on Conduction Phase of Coaxial Plasma Opening Switch

    Institute of Scientific and Technical Information of China (English)

    XU Xiang; WANG Younian

    2008-01-01

    Plasma behaviour and the scaling relations in a coaxial plasma opening switch (POS) using hydrogen plasma are studied self-consistently based on the two-dimensional magnetohydro-dynamic (MHD) equations in conjunction with the generalized Ohm's law. The vacuum region on the right of POS is included in the model and the influence of downstream flow on the conduction characteristics is discussed. It is found that with the penetration of magnetic field, the pure hydro-gen plasma is pushed downstream significantly; and POS still conducts current after the magnetic field arrives at the load edge of POS, which is different from the previous experimental results in a multispecies POS. It is because that the noticeable downstream plasma in the pure hydrogen POS may continue to conduct the current, while in the multispecies POS, the downstream plasma is unimportant so that the conduction phase ends soon after the magnetic field reaches the load edge. The scaling relation obtained from the simulations including the downstream region is consistent with the experimental results.

  10. Assessing downstream flood impacts due to a potential GLOF from Imja Tsho in Nepal

    Science.gov (United States)

    Somos-Valenzuela, M. A.; McKinney, D. C.; Byers, A. C.; Rounce, D. R.; Portocarrero, C.; Lamsal, D.

    2015-03-01

    Glacial-dominated areas pose unique challenges to downstream communities in adapting to recent and continuing global climate change, including increased threats of glacial lake outburst floods (GLOFs) that can increase risk due to flooding of downstream communities and cause substantial impacts on regional social, environmental and economic systems. The Imja glacial lake (or Imja Tsho) in Nepal, which has the potential to generate a GLOF, was studied using a two-dimensional debris-flow inundation model in order to evaluate the effectiveness of proposed measures to reduce possible flooding impacts to downstream communities by lowering the lake level. The results indicate that only minor flood impact reduction is achieved in the downstream community of Dingboche with modest (~3 m) lake lowering. Lowering the lake by 10 m shows a significant reduction in inundated area. However, lowering the lake by 20 m almost eliminates all flood impact at Dingboche. Further downstream at Phakding, the impact of the GLOF is significant and similar reductions in inundation are likely as a result of lake lowering.

  11. Assessing downstream flood impacts due to a potential GLOF from Imja Lake in Nepal

    Directory of Open Access Journals (Sweden)

    M. A. Somos-Valenzuela

    2014-11-01

    Full Text Available Glacial-dominated areas pose unique challenges to downstream communities in adapting to recent and continuing global climate change, including increased threats of glacial lake outburst floods (GLOFs that can increase risk due to flooding of downstream communities and cause substantial impacts on regional social, environmental and economic systems. The Imja glacial lake in Nepal, with potential to generate a GLOF, was studied using a two-dimensional debris flow inundation model in order to evaluate the effectiveness of proposed measures to reduce possible flooding impacts to downstream communities by lowering the lake level. The results indicate that only minor flood impact reduction is achieved in the downstream community of Dingboche with modest (~3 m lake lowering. Lowering the lake by 10 m shows a significant reduction in inundated area. However, lowering the lake by 20 m almost eliminates all flood impact at Dingboche. Further downstream at Phakding, the impact of the GLOF is significant and similar reductions in inundation are likely as a result of lake lowering.

  12. Partial migration in fishes: causes and consequences.

    Science.gov (United States)

    Chapman, B B; Hulthén, K; Brodersen, J; Nilsson, P A; Skov, C; Hansson, L-A; Brönmark, C

    2012-07-01

    Partial migration, where only some individuals from a population migrate, has been widely reported in a diverse range of animals. In this paper, what is known about the causes and consequences of partial migration in fishes is reviewed. Firstly, the ultimate and proximate drivers of partial migration are reflected upon: what ecological factors can shape the evolution of migratory dimorphism? How is partial migration maintained over evolutionary timescales? What proximate mechanisms determine whether an individual is migratory or remains resident? Following this, the consequences of partial migration are considered, in an ecological and evolutionary context, and also in an applied sense. Here it is argued that understanding the concept of partial migration is crucial for fisheries and ecosystem managers, and can provide information for conservation strategies. The review concludes with a reflection on the future opportunities in this field, and the avenues of research that are likely to be fruitful to shed light on the enduring puzzle of partial migration in fishes.

  13. Migration Helps Spread Bird Flu Worldwide

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_161473.html Migration Helps Spread Bird Flu Worldwide Scientists recommend keeping ... birds can spread bird flu worldwide and monitoring migration routes could provide early warning of outbreaks, researchers ...

  14. Migration policies and return migration with particular reference to Yugoslavia.

    Science.gov (United States)

    Chepulis, R L

    1981-09-01

    "The essay analyses some of the most recent migratory trends in Europe in the light of labour turnover, integration and assimilation. The author states that [since] World War II the expansion of the European and international capitalistic system has encouraged or discouraged, according to the various circumstances, the transferral of workers to different countries. "Particular attention has been given to the case of Yugoslavia. The changing of its migration policies has often coincided with the different modalities of flows." (summary in FRE)

  15. 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...

  16. Theoretical aspects of studying the migration processes

    Directory of Open Access Journals (Sweden)

    Dilfuza Rasulova

    2010-02-01

    Full Text Available In conditions of continuous growth of population in Uzbekistan the issue of managing the labor migration processes is becoming more important. Effective coordination of migration processes requires comprehensive study of theory and methodology of labour migration, particularly considering cases of transition countries. The paper considers some theoretic concepts that seem important for understanding the mechanism of migration princesses, suggests practical recommendations for the associated decision-making.

  17. Undocumented migration in response to climate change

    OpenAIRE

    Nawrotzki, Raphael J.; Riosmena, Fernando; HUNTER, LORI M.; Runfola, Daniel M.

    2015-01-01

    In the face of climate change induced economic uncertainty, households may employ migration as an adaptation strategy to diversify their livelihood portfolio through remittances. However, it is unclear whether such climate migration will be documented or undocumented. In this study we combine detailed migration histories with daily temperature and precipitation information for 214 weather stations to investigate whether climate change more strongly impacts undocumented or documented migration...

  18. Migration and security : history, practice, and theory

    OpenAIRE

    Aslan, Nazlı Sinem

    2010-01-01

    Cataloged from PDF version of article. Receiving states viewed international migration as a means of economic development well until late 20th century. Since then policy makers around the world have increasingly associated migration to security and sought to meet this ‘threat’ through ‘control’. In the 21st century, the significance of international migration increased further as migration flows increased and took on new forms affecting the world as a whole. This thesis look...

  19. Helicobacter pylori : migrations humaines et cancer gastrique

    OpenAIRE

    Breurec, Sébastien

    2011-01-01

    Helicobacter pylori is associated with severe gastroduodenal disorders but is also a bacterial genetic marker of human migrations. First, we provide evidence that distinct H. pylori genetic populations accompanied at least four ancient human migrations into Oceania and Southeast Asia: i) an expansion of Austronesian speaking people about 5000 years ago from Taiwan into Oceania, ii) a migration from India into Southeast Asia within the last 2000 years, iii) a migration of Austro-Asiatic speaki...

  20. EMPIRICAL-NUMERICAL ANALYSIS OF HEADCUT MIGRATION

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Headcut migration is studied by using empirical and numerical modeling approaches. Empirical formulas for the headcut migration are established using available measurement data, which consider not only the flow strength but also the properties of soil. Numerical model for the headcut migration is proposed. The influences of dynamic pressure gradient, downward flow, and bed slope on sediment entrainment are considered. The local erosion patterns and migration speeds of headcut calculated by the numerical model agree reasonably well with observed data.

  1. 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).

  2. FH535 inhibited migration and growth of breast cancer cells.

    Science.gov (United States)

    Iida, Joji; Dorchak, Jesse; Lehman, John R; Clancy, Rebecca; Luo, Chunqing; Chen, Yaqin; Somiari, Stella; Ellsworth, Rachel E; Hu, Hai; Mural, Richard J; Shriver, Craig D

    2012-01-01

    There is substantial evidence indicating that the WNT signaling pathway is activated in various cancer cell types including breast cancer. Previous studies reported that FH535, a small molecule inhibitor of the WNT signaling pathway, decreased growth of cancer cells but not normal fibroblasts, suggesting this pathway plays a role in tumor progression and metastasis. In this study, we tested FH535 as a potential inhibitor for malignant phenotypes of breast cancer cells including migration, invasion, and growth. FH535 significantly inhibited growth, migration, and invasion of triple negative (TN) breast cancer cell lines (MDA-MB231 and HCC38) in vitro. We demonstrate that FH535 was a potent growth inhibitor for TN breast cancer cell lines (HCC38 and MDA-MB-231) but not for other, non-TN breast cancer cell lines (MCF-7, T47D or SK-Br3) when cultured in three dimensional (3D) type I collagen gels. Western blotting analyses suggest that treatment of MDA-MB-231 cells with FH535 markedly inhibited the expression of NEDD9 but not activations of FAK, Src, or downstream targets such as p38 and Erk1/2. We demonstrated that NEDD9 was specifically associated with CSPG4 but not with β1 integrin or CD44 in MDA-MB-231 cells. Analyses of gene expression profiles in breast cancer tissues suggest that CSPG4 expression is higher in Basal-type breast cancers, many of which are TN, than any other subtypes. These results suggest not only a mechanism for migration and invasion involving the canonical WNT-signaling pathways but also novel strategies for treating patients who develop TN breast cancer.

  3. FH535 inhibited migration and growth of breast cancer cells.

    Directory of Open Access Journals (Sweden)

    Joji Iida

    Full Text Available There is substantial evidence indicating that the WNT signaling pathway is activated in various cancer cell types including breast cancer. Previous studies reported that FH535, a small molecule inhibitor of the WNT signaling pathway, decreased growth of cancer cells but not normal fibroblasts, suggesting this pathway plays a role in tumor progression and metastasis. In this study, we tested FH535 as a potential inhibitor for malignant phenotypes of breast cancer cells including migration, invasion, and growth. FH535 significantly inhibited growth, migration, and invasion of triple negative (TN breast cancer cell lines (MDA-MB231 and HCC38 in vitro. We demonstrate that FH535 was a potent growth inhibitor for TN breast cancer cell lines (HCC38 and MDA-MB-231 but not for other, non-TN breast cancer cell lines (MCF-7, T47D or SK-Br3 when cultured in three dimensional (3D type I collagen gels. Western blotting analyses suggest that treatment of MDA-MB-231 cells with FH535 markedly inhibited the expression of NEDD9 but not activations of FAK, Src, or downstream targets such as p38 and Erk1/2. We demonstrated that NEDD9 was specifically associated with CSPG4 but not with β1 integrin or CD44 in MDA-MB-231 cells. Analyses of gene expression profiles in breast cancer tissues suggest that CSPG4 expression is higher in Basal-type breast cancers, many of which are TN, than any other subtypes. These results suggest not only a mechanism for migration and invasion involving the canonical WNT-signaling pathways but also novel strategies for treating patients who develop TN breast cancer.

  4. Influence of Local Flow Field on Flow Accelerated Corrosion Downstream from an Orifice

    Science.gov (United States)

    Utanohara, Yoichi; Nagaya, Yukinori; Nakamura, Akira; Murase, Michio

    Flow accelerated corrosion (FAC) rate downstream from an orifice was measured in a high-temperature water test loop to evaluate the effects of flow field on FAC. Orifice flow was also measured using laser Doppler velocimetry (LDV) and simulated by steady RANS simulation and large eddy simulation (LES). The LDV measurements indicated the flow structure did not depend on the flow velocity in the range of Re = 2.3×104 to 1.2×105. Flow fields predicted by RANS and LES agreed well with LDV data. Measured FAC rate was higher downstream than upstream from the orifice and the maximum appeared at 2D (D: pipe diameter) downstream. The shape of the profile of the root mean square (RMS) wall shear stress predicted by LES had relatively good agreement with the shape of the profile of FAC rate. This result indicates that the effects of flow field on FAC can be evaluated using the calculated wall shear stress.

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

    Science.gov (United States)

    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

    2011-12-01

    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.

  6. Optimization of biopharmaceutical downstream processes supported by mechanistic models and artificial neural networks.

    Science.gov (United States)

    Pirrung, Silvia M; van der Wielen, Luuk A M; van Beckhoven, Ruud F W C; van de Sandt, Emile J A X; Eppink, Michel H M; Ottens, Marcel

    2017-01-05

    Downstream process development is a major area of importance within the field of bioengineering. During the design of such a downstream process, important decisions have to be made regarding the type of unit operations as well as their sequence and their operating conditions. Current computational approaches addressing these issues either show a high level of simplification or struggle with computational speed. Therefore, this article presents a new approach that combines detailed mechanistic models and speed-enhancing artificial neural networks. This approach was able to simultaneously optimize a process with three different chromatographic columns toward yield with a minimum purity of 99.9%. The addition of artificial neural networks greatly accelerated this optimization. Due to high computational speed, the approach is easily extendable to include more unit operations. Therefore, it can be of great help in the acceleration of downstream process development. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 2017.

  7. Migration on Wings Aerodynamics and Energetics

    CERN Document Server

    Kantha, Lakshmi

    2012-01-01

    This book is an effort to explore the technical aspects associated with bird flight and migration on wings. After a short introduction on the birds migration, the book reviews the aerodynamics and Energetics of Flight and presents the calculation of the Migration Range. In addition, the authors explains aerodynamics of the formation flight and finally introduces great flight diagrams.

  8. 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, a...

  9. [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.

  10. 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. Insigh

  11. Step-Wise Migration : Evidence from Indonesia

    NARCIS (Netherlands)

    Pardede, Elda; McCann, Philip; Venhorst, Viktor

    2016-01-01

    The objective of this paper is to study multiple internal migration trajectories in Indonesia, with special attention to step-wise migration. Step-wise migration involves moves with smaller steps from village to nearby small town, to larger town, and then to big cities rather than a direct move from

  12. Does macrophage migration factor function as a switch in septic circulation crisis?

    Directory of Open Access Journals (Sweden)

    Dr. Li Ma

    2008-07-01

    Full Text Available Circulation dysfunction-associated mortality is defined as its reduced responsiveness to circulation active agents in the pathological context of sepsis/septic shock. Macrophage migration inhibitory factor (MIF, a versatile pro-inflammatory cytokine, has been identified independently from other mediators and found to play certain roles in the “bio-vicious-gate” of circulation collapse. Cumulating evidence shows that MIF exerts its function through interaction with a body of signal molecules that are involved in functional regulation of several end-point molecules such as, carbon monoxide, insulin, complement C5a, nitric oxide, inducible nitric oxide synthase, and glucocorticoids, and these downstream mediators are linked to vascular tone differentially. Thus, MIF stays as a molecular switch at the signaling upstream to charge the downstream action of signals in sepsis-associated circulation crisis.

  13. Chemically Assisted Photocatalytic Oxidation System

    Science.gov (United States)

    Andino, Jean; Wu, Chang-Yu; Mazyck, David; Teixeira, Arthur A.

    2009-01-01

    The chemically assisted photocatalytic oxidation system (CAPOS) has been proposed for destroying microorganisms and organic chemicals that may be suspended in the air or present on surfaces of an air-handling system that ventilates an indoor environment. The CAPOS would comprise an upstream and a downstream stage that would implement a tandem combination of two partly redundant treatments. In the upstream stage, the air stream and, optionally, surfaces of the air-handling system would be treated with ozone, which would be generated from oxygen in the air by means of an electrical discharge or ultraviolet light. In the second stage, the air laden with ozone and oxidation products from the first stage would be made to flow in contact with a silica-titania photocatalyst exposed to ultraviolet light in the presence of water vapor. Hydroxyl radicals generated by the photocatalytic action would react with both carbon containing chemicals and microorganisms to eventually produce water and carbon dioxide, and ozone from the first stage would be photocatalytically degraded to O2. The net products of the two-stage treatment would be H2O, CO2, and O2.

  14. TAZ Mediates Lysophosphatidic Acid-Induced Migration and Proliferation of Epithelial Ovarian Cancer Cells

    Directory of Open Access Journals (Sweden)

    Geun Ok Jeong

    2013-07-01

    Full Text Available Background: Transcriptional co-activator with PDZ-binding motif (TAZ, a downstream effector of the Hippo pathway, has been reported to regulate organ size, tissue homeostasis, and tumorigenesis by acting as a transcriptional co-activator. Lysophosphatidic acid (LPA is a bioactive lipid implicated in tumorigenesis and metastasis of ovarian cancer through activation of G protein-coupled receptors. However, the involvement of TAZ in LPA-induced tumorigenesis of ovarian cancer has not been elucidated. Methods: In order to demonstrate the role of TAZ in LPA-stimulated tumorigenesis, the effects of LPA on TAZ expression and cell migration were determined by Western blotting and chemotaxis analyses in R182 human epithelial ovarian cancer cells. Results and Conclusion: Treatment of R182 cells with the LPA receptor inhibitor Ki16425 blocked LPA-induced cell migration. In addition, transfection of R182 cells with small interfering RNA specific for LPA receptor 1 resulted in abrogation of LPA-stimulated cell migration. LPA induced phosphorylation of ERK and p38 MAP kinase in R182 cells and pretreatment of cells with the MEK-ERK pathway inhibitor U0126, but not the p38 MAPK inhibitor SB202190, resulted in abrogation of LPA-induced cell migration. Pretreatment of R182 cells with U0126 attenuated LPA-induced mRNA levels of TAZ and its transcriptional target genes, such as CTGF and CYR61, without affecting phosphorylation level of YAP. These results suggest that MEK-ERK pathway plays a key role in LPA-induced cell migration and mRNA expression of TAZ in R182 cells, without affecting stability of TAZ protein. In addition, small interfering RNA-mediated silencing of TAZ expression attenuated LPA-stimulated migration of R182 cells. These results suggest that TAZ plays a key role in LPA-stimulated migration of epithelial ovarian cancer cells.

  15. Making the cut: Innovative methods for optimizing perfusion-based migration assays.

    Science.gov (United States)

    Holt, Andrew W; Howard, William E; Ables, Elizabeth T; George, Stephanie M; Kukoly, Cindy A; Rabidou, Jake E; Francisco, Jake T; Chukwu, Angel N; Tulis, David A

    2017-03-01

    Application of fluid shear stress to adherent cells dramatically influences their cytoskeletal makeup and differentially regulates their migratory phenotype. Because cytoskeletal rearrangements are necessary for cell motility and migration, preserving these adaptations under in vitro conditions and in the presence of fluid flow are physiologically essential. With this in mind, parallel plate flow chambers and microchannels are often used to conduct in vitro perfusion experiments. However, both of these systems currently lack capacity to accurately study cell migration in the same location where cells were perfused. The most common perfusion/migration assays involve cell perfusion followed by trypsinization which can compromise adaptive cytoskeletal geometry and lead to misleading phenotypic conclusions. The purpose of this study was to quantitatively highlight some limitations commonly found with currently used cell migration approaches and to introduce two new advances which use additive manufacturing (3D printing) or laser capture microdissection (LCM) technology. The residue-free 3D printed insert allows accurate cell seeding within defined areas, increases cell yield for downstream analyses, and more closely resembles the reported levels of fluid shear stress calculated with computational fluid dynamics as compared to other residue-free cell seeding techniques. The LCM approach uses an ultraviolet laser for "touchless technology" to rapidly and accurately introduce a custom-sized wound area in otherwise inaccessible perfusion microchannels. The wound area introduced by LCM elicits comparable migration characteristics compared to traditional pipette tip-induced injuries. When used in perfusion experiments, both of these newly characterized tools were effective in yielding similar results yet without the limitations of the traditional modalities. These innovative methods provide valuable tools for exploring mechanisms of clinically important aspects of cell

  16. Analysis of the longitudinal dependence of the downstream fluence of large solar energetic proton events

    Science.gov (United States)

    Pacheco, Daniel; Sanahuja, Blai; Aran, Angels; Agueda, Neus; Jiggens, Piers

    2016-07-01

    Simulations of the solar energetic particle (SEP) intensity-time profiles are needed to estimate the radiation environment for interplanetary missions. At present, the physics-based models applied for such a purpose, and including a moving source of particles, are not able to model the portion of the SEP intensity enhancement occurring after the coronal/interplanetary shock crossing by the observer (a.k.a. the downstream region). This is the case, for example, of the shock-and-particle model used to build the SOLPENCO2 code. SOLPENCO2 provides the statistical modelling tool developed in the ESA/SEPEM project for interplanetary missions with synthetic SEP event simulations for virtual spacecraft located at heliocentric distances between 0.2 AU and 1.6 AU (http://dev.sepem.oma.be/). In this work we present an analysis of 168 individual SEP events observed at 1 AU from 1988 to 2013. We identify the solar eruptive phenomena associated with these SEP events, as well as the in-situ passage of interplanetary shocks. For each event, we quantify the amount of fluence accounted in the downstream region, i.e. after the passage of the shock, at the 11 SEPEM reference energy channels (i.e., from 5 to 300 MeV protons). First, from the subset of SEP events simultaneously detected by near Earth spacecraft (using SEPEM reference data) and by one of the STEREO spacecraft, we select those events for which the downstream region can be clearly determined. From the 8 selected multi-spacecraft events, we find that the western observations of each event have a minor downstream contribution than their eastern counterpart, and that the downstream-to-total fluence ratio of these events decreases as a function of the energy. Hence, there is a variation of the downstream fluence with the heliolongitude in SEP events. Based on this result, we study the variation of the downstream-to-total fluence ratios of the total set of individual events. We confirm the eastern-to-western decrease of the

  17. Factors Influencing the Disturbed Flow Patterns Downstream of Curved Atherosclerotic Arteries

    Institute of Scientific and Technical Information of China (English)

    Biyue Liu

    2008-01-01

    Pulsatile blood flows in curved atherosclerotic arteries are studied by com-puter simulations. Computations are carried out with various values of physiological parameters to examine the effects of flow parameters on the disturbed flow patterns downstream of a curved artery with a stenosis at the inner wall. The numerical re-sults indicate a strong dependence of flow pattern on the blood viscosity and inlet flow rate, while the influence of the inlet flow profile to the flow pattem in downstream is negligible.

  18. 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...

  19. Extraction and purification methods in downstream processing of plant-based recombinant proteins.

    Science.gov (United States)

    Łojewska, Ewelina; Kowalczyk, Tomasz; Olejniczak, Szymon; Sakowicz, Tomasz

    2016-04-01

    During the last two decades, the production of recombinant proteins in plant systems has been receiving increased attention. Currently, proteins are considered as the most important biopharmaceuticals. However, high costs and problems with scaling up the purification and isolation processes make the production of plant-based recombinant proteins a challenging task. This paper presents a summary of the information regarding the downstream processing in plant systems and provides a comprehensible overview of its key steps, such as extraction and purification. To highlight the recent progress, mainly new developments in the downstream technology have been chosen. Furthermore, besides most popular techniques, alternative methods have been described.

  20. 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.

  1. 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.

  2. Monomer Migration and Annihilation Processes

    Institute of Scientific and Technical Information of China (English)

    KE Jian-Hong; LIN Zhen-Quan; ZHUANG You-Yi

    2005-01-01

    We propose a two-species monomer migration-annihilation model, in which monomer migration reactions occur between any two aggregates of the same species and monomer annihilation reactions occur between two different species. Based on the mean-field rate equations, we investigate the evolution behaviors of the processes. For the case with an annihilation rate kernel proportional to the sizes of the reactants, the aggregation size distribution of either species approaches the modified scaling form in the symmetrical initial case, while for the asymmetrical initial case the heavy species with a large initial data scales according to the conventional form and the light one does not scale. Moreover,at most one species can survive finally. For the case with aconstant annihilation rate kernel, both species may scale according to the conventional scaling law in the symmetrical case and survive together at the end.

  3. 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.

  4. Population forecasting with endogenous migration: an application to trans-Tasman migration.

    Science.gov (United States)

    Gorbey, S; James, D; Poot, J

    1999-04-01

    "This article focuses on forecasting migration between Australia and New Zealand (trans-Tasman migration), which is largely visa-free and therefore resembles internal migration. Net trans-Tasman migration is a major component of New Zealand population change and is embedded in this article in a Bayesian or unrestricted vector autoregression (VAR) model, which includes foreign and domestic economic variables. When time series of net migration are available, this approach provides a useful input into forecasting population growth in the short run in the absence of major policy changes. This conclusion applies equally to interregional migration and to unrestricted international migration between economically integrated nations."

  5. Developing a new resource on international nurse migration: the international centre on nurse migration.

    Science.gov (United States)

    Nichols, Barbara; Oulton, Judith

    2005-08-01

    A new collaborative project on nurse migration was recently launched by the International Council of Nurses and the Commission on Graduates of Foreign Nursing Schools. This collaboration, the International Centre on Nurse Migration, guided by the principles of ethical recruitment and equitable treatment of migrating nurses, focuses on promoting, collecting, creating, and disseminating data and information on nurse migration; acting as a resource center; tracking trends and patterns of global health care workforce migration; analyzing policy; generating policy options; advocating for sound policy concerning nurse migration; promoting, undertaking, and disseminating research; providing consultant and expert advice; and offering continuing education about migration.

  6. Mexican Migration: Assessing Root Causes

    Science.gov (United States)

    2007-06-01

    66 Figure 4 is derived from John Scott, “Metas y Mecanismo ,” Centro de Investigacion y Docencia Economicas...John Scott, “Metas y Mecanismo ,” 4. 31 Another explanation for the increase in migration concerns neither the Mexican economy nor the Mexican...Dominant Regime,” 135. 82 John Scott, “Metas y Mecanismo ,” 5. 83 World Bank: Mexican Health Foundation, “Trends and Empirical Causes of Violent

  7. 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

  8. Marriage migration in the Netherlands

    OpenAIRE

    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 the Netherlands for a lasting relationship is then known as marriage migrant. In this publication we present a statistical picture of marriage migrants, but above all we allow them and their partners t...

  9. Live Migration Of Parallel Applications

    OpenAIRE

    Romero, Raul Fabian

    2010-01-01

    Romero, Raul F. M.S., Purdue University, August, 2010. Live Migration of Parallel Applications. Major Professor: Thomas J. Hacker. It has been observed on engineering and scientific data centers that the absence of a clear separation between software and hardware can severely affect parallel applications. Applications that run across several nodes tend to be greatly affected because a single computational failure present in one of the nodes often leads the entire application to produce ...

  10. Influences of environmental cues, migration history and habitat familiarity on partial migration

    DEFF Research Database (Denmark)

    Skov, Christian; Aarestrup, Kim; Baktoft, Henrik;

    2010-01-01

    The factors that drive partial migration in organisms are not fully understood. Roach (Rutilus rutilus), a freshwater fish, engage in partial migration where parts of populations switch between summer habitats in lakes and winter habitats in connected streams. To test if the partial migration trait...... is phenotypically plastic or has genetic components, we translocated roach from 2 populations with different opportunities for migration to a lake with migration opportunity, containing a local roach population. This enabled monitoring of partial migration of fish in 3 different situations: 1) previous opportunity...... decisions. Individuals without previous migration opportunity migrated at a lower proportion and with different small-scale migration patterns, suggesting that also genetic components are involved in the expression of the partial migration trait....

  11. SUPER-ECCENTRIC MIGRATING JUPITERS

    Energy Technology Data Exchange (ETDEWEB)

    Socrates, Aristotle; Katz, Boaz; Dong Subo; Tremaine, Scott [Institute for Advanced Study, Princeton, NJ 08540 (United States)

    2012-05-10

    An important class of formation theories for hot Jupiters involves the excitation of extreme orbital eccentricity (e = 0.99 or even larger) followed by tidal dissipation at periastron passage that eventually circularizes the planetary orbit at a period less than 10 days. In a steady state, this mechanism requires the existence of a significant population of super-eccentric (e > 0.9) migrating Jupiters with long orbital periods and periastron distances of only a few stellar radii. For these super-eccentric planets, the periastron is fixed due to conservation of orbital angular momentum and the energy dissipated per orbit is constant, implying that the rate of change in semi-major axis a is a-dot {proportional_to}a{sup 1/2} and consequently the number distribution satisfies dN/d log a{proportional_to}a{sup 1/2}. If this formation process produces most hot Jupiters, Kepler should detect several super-eccentric migrating progenitors of hot Jupiters, allowing for a test of high-eccentricity migration scenarios.

  12. Super-Eccentric Migrating Jupiters

    CERN Document Server

    Socrates, Aristotle; Dong, Subo; Tremaine, Scott

    2011-01-01

    An important class of formation theories for hot Jupiters involves the excitation of extreme orbital eccentricity (e=0.99 or even larger) followed by tidal dissipation at periastron passage that eventually circularizes the planetary orbit at a period less than 10 days. In a steady state, this mechanism requires the existence of a significant population of super-eccentric (e>0.9) migrating Jupiters with long orbital periods and periastron distances of only a few stellar radii. For these super-eccentric planets, the periastron is fixed due to conservation of orbital angular momentum and the energy dissipated per orbit is constant, implying that the rate of change in semi-major axis a is \\dot a \\propto a^0.5 and consequently the number distribution satisfies dN/dlog a\\propto a^0.5. If this formation process produces most hot Jupiters, Kepler should detect several super-eccentric migrating progenitors of hot Jupiters, allowing for a test of high-eccentricity migration scenarios.

  13. 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.

  14. 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.

  15. RETURN MIGRATION – REASONS, CONSEQUENCES AND BENEFITS

    Directory of Open Access Journals (Sweden)

    RAMONA PÎRVU

    2012-12-01

    Full Text Available Return migration is probably the aspect of the migration cycle, which was granted the lowest attention, perhaps because most research resources are located in highly developed countries, while most of the returning most returnees return to developing countries. This is especially unfortunate because perceptions about the process of returning to the country of origin and attitudes towards returning migrants have a significant impact on migrants and their host communities. Rollback, sometimes called remigration, is considered by some authors as the final stage of the migration process, which further comprises the step preparation / decision to migrate and actual migration phase or installation of migrant destination country selected.

  16. Monitoring of Downstream Salmon and Steelhead at Federal Hydroelectric Facilities, 1991 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Hawkes, Lynette A.; Martinson, Rick D.; Smith, W. William (Northwest and Alaska Fisheries Science Center, Environmental and Technical Services Division, Portland, OR)

    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.

  17. 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.

  18. Fluid migration in ductile shear zones

    Science.gov (United States)

    Fusseis, Florian; Menegon, Luca

    2014-05-01

    Fluid migration in metamorphic environments depends on a dynamically evolving permeable pore space, which was rarely characterised in detail. The data-base behind our understanding of the 4-dimensional transport properties of metamorphic rocks is therefore fragmentary at best, which leaves conceptual models poorly supported. Generally, it seems established that deformation is a major driver of permeability generation during regional metamorphism, and evidence for metamorphic fluids being channelled in large scale shear zones has been found in all depth segments of the continental crust. When strain localizes in ductile shear zones, the microfabric is modified until a steady state mylonite is formed that supports large deformations. A dynamic porosity that evolves during mylonitisation controls the distinct transport pathways along which fluid interacts with the rock. This dynamic porosity is controlled by a limited number of mechanisms, which are intrinsically linked to the metamorphic evolution of the rock during its deformational overprint. Many mid- and lower-crustal mylonites comprise polyphase mixtures of micron-sized grains that show evidence for deformation by dissolution/precipitation-assisted viscous grain boundary sliding. The establishment of these mineral mixtures is a critical process, where monomineralic layers are dispersed and grain growth is inhibited by the heterogeneous nucleation of secondary mineral phases at triple junctions. Here we show evidence from three different mid- and lower-crustal shear zones indicating that heterogeneous nucleation occurs in creep cavities. Micro- and nanotomographic observations show that creep cavities provide the dominant form of porosity in these ultramylonites. They control a "granular fluid pump" that directs fluid migration and hence mass transport. The granular fluid pump operates on the grain scale driven by viscous grain boundary sliding, and requires only small amounts of fluid. The spatial arrangement of

  19. Social Physics and China's Population Migration

    Science.gov (United States)

    Wang, Yun-Lin; Li, Ding

    Based on the social physics theory, this paper analyzes the economic disparities between different regions in China, and contributes a conceptual model of population migration among eastern, central, western and north-eastern regions. The national 1% population sample investigation data is adopted to build a network of inter-provincial population migration, and the population migration network is analyzed with social network analysis. The results are shown that there is a very strong correlation between migrant population and economy disparity in China, and the migration with obviously geographical characteristics. The eastern region is the main areas for migration-inflow; the central region is the main areas of migration-outflow; the western region is relatively “locked-up”, with a little of population flow; and the migration of the northeast is mainly within its own regional territory.

  20. Migration from New EU Member Countries

    DEFF Research Database (Denmark)

    Pytlikova, Mariola

    2007-01-01

    The main purpose of the paper is to give predictions of the migration potential from the 7 new EU member countries to the EEA/EU-13 countries. Being able to analyze 'real' migration behavior from these particular countries over the period 1990-2000 helps me to avoid problems related to (double) out......-of sample forecasts and to the assumption of invariance of migration behavior across a space that previous studies had to hold. Results of the econometric analyses reveal the importance of controlling for pairs of countries unobserved heterogeneity. Preliminary results regarding the predictions of future...... gross and net migration flows show that the magnitude of the estimated gross and net migration flows is relatively high and lower, respectively, compared to forecasts from previous studies. Such a development in gross and net migration flows indicates that migration from the new EU member countries...

  1. Tracing The Largest Seasonal Migration on Earth

    CERN Document Server

    Wang, Xianwen; Mao, Wenli; Hu, Zhigang; Gu, Li

    2014-01-01

    It is estimated that over 3.6 billion passengers are travelling during the Chinese Spring Festival travel season. They leave their working cities and return their hometowns to enjoy annual family time, and back to cities after the holiday. In this study, with the massive location-based data collected from millions of smartphone users, we propose a novel method to trace the migration flow and explore the migration patterns of Chinese people. From the temporal perspective, we explore the migration trend over time during a 34-days period, about half a month before and after the Spring Festival. From the spatial perspective, the migration directions and routes are estimated and quantified, and the migration flow is visualized. The spatial range of influence of developed regions could be reflected with the destinations of migration, the migration destinations and originations have obvious characteristic of geographical proximity.

  2. Trends in return migration to the South.

    Science.gov (United States)

    Long, L H; Hansen, K A

    1975-11-01

    The rate of return migration to the South rose by nearly 19 percent between the late 1950's and the late 1960's and was an important factor in changing the South's overall migration pattern. But an increase in the rate of return migration was somewhat less important in changing Southern migration than (1) a decline in the rate of out-migration of native Southerners and (2) an increase in the rate at which non-Southern-born persons move to the South. The probability of former migrants returning to the South was over four times greater for whites than for blacks in the 1955-1960 period and three and one-fourth times greater in the 1965-1970 period. Since 1970 the rate of return migration has apparently continued to rise at a faster rate for blacks, but the black rate of return migration is still below the white rate.

  3. 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.

  4. European Perspectives Approach to Asylum and Migration

    Directory of Open Access Journals (Sweden)

    Georgeta Modiga

    2012-05-01

    Full Text Available Migration is a complex process, with a multinational character that can not be managed onlyunilaterally or bilaterally, but through effective management to take into account the benefit of all involvedand changing characteristics of the migration process. Regarding the European Union, framed in the generalcontext, it aims to promote a comprehensive migration policy, to provide a coherent and efficient manner tomeet the challenges and opportunities that migration presents. Multilateral approach under considerationcovers all phases of migration, aiming to seize them and present it at the same time, to implement effectivepolicies and measures concerning illegal migration and human trafficking. It is based on generally acceptedprinciples relating to subsidiary, proportionality, solidarity and respect for law and the economic and social.From this perspective, the present study examines the quantitative aspects of migration as well as qualitativeaspects, with emphasis on the challenges that they face Romania, from the status of EU member country.

  5. Type I Planetary Migration with MHD Turbulence

    CERN Document Server

    Laughlin, G; Adams, F; Laughlin, Gregory; Steinacker, Adriane; Adams, Fred

    2004-01-01

    This paper examines how type I planet migration is affected by the presence of turbulent density fluctuations in the circumstellar disk. For type I migration, the planet does not clear a gap in the disk and its secular motion is driven by torques generated by the wakes it creates in the surrounding disk fluid. MHD turbulence creates additional density perturbations that gravitationally interact with the planet and can dominate the torques produced by the migration mechanism itself. This paper shows that conventional type I migration can be readily overwhelmed by turbulent perturbations and hence the usual description of type I migration should be modified in locations where the magnetorotational instability is active. In general, the migrating planet does not follow a smooth inward trned, but rather exhibits a random walk through phase space. Our main conclusion is that MHD turbulence will alter the time scales for type I planet migration and -- because of chaos -- requires the time scales to be described by ...

  6. 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.

  7. 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.

  8. Muskingum equation based downstream sediment flow simulation models for a river system

    Institute of Scientific and Technical Information of China (English)

    Briti Sundar Sil; Parthasarathi Choudhury

    2016-01-01

    Applications of sediment transport and water flow characteristics based sediment transport simulation models for a river system are presented in this study. An existing water–sediment model and a new sediment–water model are used to formulate the simulation models representing water and sediment movement in a river system. The sediment–water model parameters account for water flow characteristics embodying sediment transport properties of a section. The models are revised formulations of the multiple water inflows model describing water movement through a river system as given by the Muskingum principle. The models are applied to a river system in Mississippi River basin to estimate downstream sediment concentration, sediment discharge, and water discharge. River system and the river section parameters are estimated using a revised and the original multiple water inflows models by applying the genetic algorithm. The models estimate downstream sediment transport rates on the basis of upstream sediment/water flow rates to a system. Model performance is evaluated by using standard statistical criteria;downstream water discharge resulting from the original multiple water inflows model using the estimated river system parameters indicate that the revised models satisfactorily describe water movement through a river system. Results obtained in the study demonstrate the applicability of the sediment transport and water flow characteristics-based simulation models in predicting downstream sediment transport and water flow rates in a river system.

  9. SIMULATION AND DYNAMIC VISUALIZATION OF FLOW AND SEDIMENT MOTION DOWNSTREAM OF CUIJIAYING DAM

    Institute of Scientific and Technical Information of China (English)

    YU Ming-hui; XU Jin-jun; WAN Yuan-yang; DOU Shen-tang

    2006-01-01

    Based on a depth-averaged 2D numerical river model, the flow and sediment movement downstream of the Cuijiaying dam Hanjiang River(China) are investigated. A new technique is employed to achieve synchronous dynamic visualization of topography and velocity field. The calculating results can reflect the relationship between flow and corresponding topography.

  10. 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.; 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 n

  11. Biochemistry in an Industrial Context: Methods of Protein Purification and Downstream Processing.

    Science.gov (United States)

    Weathers, Pamela J.

    1988-01-01

    Explores a graduate level bioprocess engineering course in protein purification and downstream processing. Designed to provide students with hands-on training in the design and implementation of product processing for the biotechnology industry. Includes syllabus and plan of study. (MVL)

  12. Systems-wide analysis of BCR signalosomes and downstream phosphorylation and ubiquitylation

    DEFF Research Database (Denmark)

    Satpathy, Shankha; Wagner, Sebastian A; Beli, Petra;

    2015-01-01

    ) and to investigate the dynamics of downstream phosphorylation and ubiquitylation signaling. We identify most of the previously known components of BCR signaling, as well as many proteins that have not yet been implicated in this system. BCR activation leads to rapid tyrosine phosphorylation and ubiquitylation...

  13. In bed and downstream hot gas desulphurization during solid fuel gasification: A review

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Xiangmei; de Jong, Wiebren; Pal, Ranadeep; Verkooijen, Adrian H.M. [Faculty of Mechanical, Maritime and Materials Engineering, Process and Energy Department, Energy Technology Section, Delft University of Technology, Leeghwaterstraat 44, 2628 CA, Delft (Netherlands)

    2010-08-15

    Syngas produced by gasification process of biomass fuels is an environmental friendly alternative to conventional petrochemical fuels for the production of electricity, hydrogen, synthetic transportation biofuels and other chemicals. However, the advanced utilization of syngas is significantly limited due to the contaminants which can seriously deactivate the catalysts used for downstream reaction such as steam reforming methane, Fischer-Tropsch synthesis and corrosion of downstream equipments such as a gas turbine. Among the contaminants, sulphur compounds produced in the gasification process, which are mainly H{sub 2}S with small amounts of COS, CS{sub 2} and thiophenes depending on process conditions, must be removed. For biomass feedstock advances are required in the cleanup technologies and processes to upgrade the raw product gas with minimal impact on the overall process efficiency. Hot gas desulphurization (HGD) can improve the overall thermal efficiency due to the elimination of fuel gas cooling and associated heat exchangers. With this aim, the present review paper highlights currently developed methods used for desulphurization of hot gas produced from gasification process of solid fuels. The methods presented here are for both in situ and downstream sulphur capture. Also, the attention is paid to the regeneration of the used materials. In situ sulphur capture is mainly done by using calcium-based sorbents such as limestone and dolomite, whereas downstream sulphur capture is mainly focused on the use of regenerable single, mixed, and supported metal oxides. A comparison is indicated at the end to show the sulphur loading of various materials. (author)

  14. Hemodynamics analysis of patient-specific carotid bifurcation: a CFD model of downstream peripheral vascular impedance.

    Science.gov (United States)

    Dong, Jingliang; Wong, Kelvin K L; Tu, Jiyuan

    2013-04-01

    The study of cardiovascular models was presented in this paper based on medical image reconstruction and computational fluid dynamics. Our aim is to provide a reality platform for the purpose of flow analysis and virtual intervention outcome predication for vascular diseases. By connecting two porous mediums with transient permeability at the downstream of the carotid bifurcation branches, a downstream peripheral impedance model was developed, and the effect of the downstream vascular bed impedance can be taken into consideration. After verifying its accuracy with a healthy carotid bifurcation, this model was implemented in a diseased carotid bifurcation analysis. On the basis of time-averaged wall shear stress, oscillatory shear index, and the relative residence time, fractions of abnormal luminal surface were highlighted, and the atherosclerosis was assessed from a hemodynamic point of view. The effect of the atherosclerosis on the transient flow division between the two branches because of the existence of plaque was also analysed. This work demonstrated that the proposed downstream peripheral vascular impedance model can be used for computational modelling when the outlets boundary conditions are not available, and successfully presented the potential of using medical imaging and numerical simulation to provide existing clinical prerequisites for diagnosis and therapeutic treatment.

  15. 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 an

  16. 33 CFR 222.2 - Acquisition of lands downstream from spillways for hydrologic safety purposes.

    Science.gov (United States)

    2010-07-01

    ... hazards of spillway flow. In fact, debris may be transported to downstream areas that otherwise would not be adversely affected. Extreme erosion may result from high velocities and turbulence. Both debris... depth. (iii) Flood duration. (iv) Velocities. (v) Debris and erosion. (2) Determine the combinations...

  17. Effect of Pulsed Plasma Jets on the Recovering Boundary Layer Downstream of a Reflected Shock Interaction

    Science.gov (United States)

    Greene, Benton; Clemens, Noel; Magari, Patrick; Micka, Daniel; Ueckermann, Mattheus

    2015-11-01

    Shock-induced turbulent boundary layer separation can have many detrimental effects in supersonic inlets including flow distortion and instability, structural fatigue, poor pressure recovery, and unstart. The current study investigates the effect of pulsed plasma jets on the recovering boundary layer downstream of a reflected shock wave-boundary layer interaction. The effects of pitch and skew angle of the jet as well as the heating parameter and discharge time scale are tested using several pulsing frequencies. In addition, the effect of the plasma jets on the undisturbed boundary layer at 6 mm and 11 mm downstream of the jets is measured. A pitot-static pressure probe is used to measure the velocity profile of the boundary layer 35 mm downstream of the plasma jets, and the degree of boundary layer distortion is compared between the different models and run conditions. Additionally, the effect of each actuator configuration on the shape of the mean separated region is investigated using surface oil flow visualization. Previous studies with lower energy showed a weak effect on the downstream boundary layer. The current investigation will attempt to increase this effect using a higher-energy discharge. Funded by AFRL through and SBIR in collaboration with Creare, LLC.

  18. The Relative Frequency of Rossby Wave Train Triggering Mechanisms Associated with Downstream Development Over Europe

    Science.gov (United States)

    2014-06-01

    diabatic Rossby vortices. 14. SUBJECT TERMS Rossby wave train, downstream development, tropopause polar vortex, warm conveyor belt, diabatic Rossby...extratropical transition of tropical cyclones, and six (16%) by diabatic Rossby vortices. vi THIS PAGE INTENTIONALLY LEFT BLANK vii TABLE OF CONTENTS...9  3.  Diabatic Rossby Vortex .....................................................................12  4.  Extratropical

  19. MIIT Convened Work Meeting for Upstream and Downstream Cooperation Mechanism of Aluminum Material For Civilian Aircraft

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    On September 15,2015,the Department of Raw Material Industry and the Department of Equipment Industry of the Ministry of Industry and Information Technology(MIIT)jointly organized and convened the first work meeting for upstream and downstream cooperation mechanism of aluminum material for civilian aircraft in Shanghai.Entrusted by Vice

  20. Changes in biodiversity and ecosystem function downstream from mountaintop removal and valley fill coal mining

    Science.gov (United States)

    Mountaintop removal and valley fill coal mining has altered the physicochemical landscape of the Central Appalachian region in the U.S. Increased specific conductance and levels of component ions downstream from valley fill sites are toxic to aquatic life and can negatively impa...

  1. Flow diverter assisted coil embolization of a very small ruptured ophthalmic artery aneurysm.

    Science.gov (United States)

    Dornbos, David; Pillai, Promod; Sauvageau, Eric

    2016-06-01

    Small ruptured aneurysms present a unique problem to endovascular therapy. We report a case in which a patient presented with subarachnoid hemorrhage and a very small ruptured ophthalmic artery aneurysm, for which endovascular therapy was preferred secondary to severe cardiac comorbidities. Due to the aneurysm size, a small 1.5 mm coil was needed, but presented a significant risk of migration. Conventional stent assisted coiling was considered suboptimal as the small coil could have easily migrated through the strut. We present a novel technique of flow diverter assisted coil embolization in which a coil was placed within the aneurysm and a pipeline embolization device was then partially deployed, jailing the microcatheter and coil mass. Once in place, the coil was detached, securing the aneurysm, and preventing coil migration. Through the use of a flow diverter, some degree of aneurysm protection would still be expected in the event of coil migration toward the ophthalmic artery origin.

  2. Streamflow gain-loss characteristics of Elkhead Creek downstream from Elkhead Reservoir near Craig, Colorado, 2009

    Science.gov (United States)

    Ruddy, Barbara C.

    2010-01-01

    The U.S. Geological Survey (USGS), in cooperation with the Colorado Water Conservation Board, the Upper Colorado River Endangered Fish Recovery Program (UCREFRP), Colorado Division of Water Resources, and City of Craig studied the gain-loss characteristics of Elkhead Creek downstream from Elkhead Reservoir to the confluence with the Yampa River during August through October 2009. Earlier qualitative interpretation of streamflow data downstream from the reservoir indicated that there could be a transit loss of nearly 10 percent. This potential loss could be a significant portion of the releases from Elkhead Reservoir requested by UCREFRP during late summer and early fall for improving critical habitat for endangered fish downstream in the Yampa River. Information on the gain-loss characteristics was needed for the effective management of the reservoir releases. In order to determine streamflow gain-loss characteristics for Elkhead Creek, eight measurement sets were made at four strategic instream sites and at one diversion from August to early October 2009. An additional measurement set was made after the study period during low-flow conditions in November 2009. Streamflow measurements were made using an Acoustic Doppler Velocimeter to provide high accuracy and consistency, especially at low flows. During this study, streamflow ranged from about 5 cubic feet per second up to more than 90 cubic feet per second with step increments in between. Measurements were made at least 24 hours after a change in reservoir release (streamflow) during steady-state conditions. The instantaneous streamflow measurements and the streamflow volume comparisons show the reach of Elkhead Creek immediately downstream from Elkhead Reservoir to the streamflow-gaging station 09246500, Elkhead Creek near Craig, CO, is neither a gaining nor losing reach. The instantaneous measurements immediately downstream from the dam and the combined measurements of Norvell ditch plus streamflow

  3. 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.

  4. 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.

  5. Development of an idealised downstream cyclone: Eulerian and Lagrangian perspective on the kinetic energy

    Directory of Open Access Journals (Sweden)

    Lukas Papritz

    2013-03-01

    Full Text Available In this idealised modelling study, the development of a downstream cyclone, which closely follows the life-cycle of a Shapiro-Keyser cyclone, is addressed from a quasi-geostrophic kinetic energy perspective. To this end a simulation of a dry, highly idealised, dispersive baroclinic wave, developing a primary and a downstream cyclone, is performed. Kinetic energy and processes contributing to its tendency – in particular baroclinic conversion and ageostrophic geopotential fluxes – are investigated in three dimensions both in an Eulerian and a Lagrangian framework from the genesis of the downstream cyclone as an upper-level kinetic energy centre, over frontal fracture to the fully developed cyclone showing the characteristic T-bone surface frontal structure, with a strong low-level jet along the bent-back front. Initially the downstream cyclone grows by the convergence of ageostrophic geopotential fluxes from the primary cyclone, but as vertical motions intensify this process is replaced by baroclinic conversion in the warm sector. We show that kinetic energy released in the warm sector is radiated away at all levels by ageostrophic geopotential fluxes: in the upper troposphere they are directed downstream, while in the lower troposphere they radiate kinetic energy to the rear of the cyclone. Thereby, vertical ageostrophic geopotential fluxes, their location and divergence, are identified to play a major role in the intensification of the cyclone in the lower troposphere and for the formation of the low-level jet. Low-level rearward ageostrophic geopotential fluxes converging along the bent-back front are shown to be a general characteristic of an eastward propagating baroclinic wave.

  6. 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.

  7. 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

  8. 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, Y.; 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 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. We found 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.

  9. 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

  10. Assistance Focus: Africa (Brochure)

    Energy Technology Data Exchange (ETDEWEB)

    2014-12-01

    The Clean Energy Solutions Center Ask an Expert service connects governments seeking policy information and advice with one of more than 30 global policy experts who can provide reliable and unbiased quick-response advice and information. The service is available at no cost to government agency representatives from any country and the technical institutes assisting them. This publication presents summaries of assistance provided to African governments, including the benefits of that assistance.

  11. The heparan sulfate-modifying enzyme glucuronyl C5-epimerase HSE-5 controls Caenorhabditis elegans Q neuroblast polarization during migration.

    Science.gov (United States)

    Wang, Xiangming; Liu, Jianhong; Zhu, Zhiwen; Ou, Guangshuo

    2015-03-15

    Directional cell migration is fundamental for neural development, and extracellular factors are pivotal for this process. Heparan sulfate proteoglycans (HSPGs) that carry long chains of differentially modified sugar residues contribute to extracellular matrix; however, the functions of HSPG in guiding cell migration remain elusive. Here, we used the Caenorhabditis elegans mutant pool from the Million Mutation Project and isolated a mutant allele of the heparan sulfate-modifying enzyme glucuronyl C5-epimerase HSE-5. Loss-of-function of this enzyme resulted in defective Q neuroblast migration. We showed that hse-5 controlled Q cell migration in a cell non-autonomous manner. By performing live cell imaging in hse-5 mutant animals, we found that hse-5 controlled initial polarization during Q neuroblast migration. Furthermore, our genetic epistasis analysis demonstrated that lon-2 might act downstream of hse-5. Finally, rescue of the hse-5 mutant phenotype by expression of human and mouse hse-5 homologs suggested a conserved function for this gene in neural development. Taken together, our results indicated that proper HSPG modification in the extracellular matrix by HSE-5 is essential for neuroblast polarity during migration.

  12. 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

  13. 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

  14. Savings, remittances, and return migration.

    Science.gov (United States)

    Merkle, L; Zimmermann, K F

    1992-01-01

    "We use a data set of immigrants to West Germany to simultaneously study both savings and remittances which we relate to individual characteristics, economic variables, migration experiences and remigration plans. Section 2 discusses the basic hypotheses and explains the data. Section 3 presents the empirical study and Section 4 summarizes." The results suggest that "savings and remittances of migrants can be well explained by remigration plans and economic as well as demographic variables. However, the planned future duration of residence in Germany has a negative and significant effect only on remittances."

  15. 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.

  16. 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.

  17. Assisted suicide and euthanasia.

    Science.gov (United States)

    van der Heide, Agnes

    2013-01-01

    Several countries have adopted laws that regulate physician assistance in dying. Such assistance may consist of providing a patient with a prescription of lethal medication that is self-administered by the patient, which is usually referred to as (physician) assistance in suicide, or of administering lethal medication to a patient, which is referred to as euthanasia. The main aim of regulating physician assistance in dying is to bring these practices into the open and to provide physicians with legal certainty. A key condition in all jurisdictions that have regulated either assistance in suicide or euthanasia is that physicians are only allowed to engage in these acts upon the explicit and voluntary request of the patient. All systems that allow physician assistance in dying have also in some way included the notion that physician assistance in dying is only accepted when it is the only means to address severe suffering from an incurable medical condition. Arguments against the legal regulation of physician assistance in dying include principled arguments, such as the wrongness of hastening death, and arguments that emphasize the negative consequences of allowing physician assistance in dying, such as a devaluation of the lives of older people, or people with chronic disease or disabilities. Opinion polls show that some form of accepting and regulating euthanasia and physician assistance in suicide is increasingly supported by the general population in most western countries. Studies in countries where physician assistance in dying is regulated suggest that practices have remained rather stable in most jurisdictions and that physicians adhere to the legal criteria in the vast majority of cases.

  18. 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.

  19. Rapidly activated epidermal growth factor receptor mediates lipopolysaccharide-triggered migration of microglia.

    Science.gov (United States)

    Qu, Wen-Sheng; Liu, Jun-Li; Li, Chun-Yu; Li, Xiao; Xie, Min-Jie; Wang, Wei; Tian, Dai-Shi

    2015-11-01

    Previous reports have suggested that epidermal growth factor receptor (EGFR) is involved in microglia activation characterized by cell morphology changes, cytokine production and cell migration; and the biochemical regulation of the microglia migration is a potential therapeutic target following CNS inflammatory damages. However, the role of EGFR in microglia motility after inflammatory stimulation remains unknown. In the present study, lipopolysaccharide (LPS) was found to trigger rapid EGFR phosphorylation within 10 min, which was sustained during long-term stimulation in both primary microglial cells and the cultured BV2 microglial cells, furthermore, blocking EGFR phosphorylation by AG1478 significantly attenuated the LPS-induced chemotactic and chemokinetic migration of microglia. In addition, LPS could initiate calcium oscillation in microglia during live-cell recording, however, an intracellular calcium chelator and a selective inhibitor of calcium/calmodulin-dependent protein kinase II, but not an extracellular calcium chelator, remarkably suppressed the LPS-induced EGFR phosphorylation in BV2 microglia cells. As EGFR is not a traditional receptor for LPS, these findings suggest that the rapid phosphorylation of EGFR is attributed to the LPS-triggered intracellular calcium mobilization. By examining the downstream signals of EGFR, we further proved that extracellular signal-regulated kinase (ERK) is essential for EGFR-mediated microglia migration, because ERK inhibition attenuated the chemotactic and chemokinetic migration of microglia that had been induced by either LPS or EGF. Collectively, these results suggest that LPS could trigger the rapid phosphorylation of EGFR and subsequent ERK activation through mobilizing calcium activity, which underlies the microglia migration in an inflammatory condition.

  20. The tumor suppressor Lgl1 regulates front-rear polarity of migrating cells.

    Science.gov (United States)

    Ravid, Shoshana

    2014-01-01

    Cell migration is a highly integrated, multistep process that plays an important role in physiological and pathological processes. The migrating cell is highly polarized, with complex regulatory pathways that integrate its component processes spatially and temporally. The Drosophila tumor suppressor, Lethal (2) giant larvae (Lgl), regulates apical-basal polarity in epithelia and asymmetric cell division. But little is known about the role of Lgl in establishing cell polarity in migrating cells. Recently, we showed that the mammalian Lgl1 interacts directly with non-muscle myosin IIA (NMIIA), inhibiting its ability to assemble into filaments in vitro. Lgl1 also regulates the cellular localization of NMIIA, the maturation of focal adhesions, and cell migration. We further showed that phosphorylation of Lgl1 by aPKCζ prevents its interaction with NMIIA and is important for Lgl1 and acto-NMII cytoskeleton cellular organization. Lgl is a critical downstream target of the Par6-aPKC cell polarity complex; we showed that Lgl1 forms two distinct complexes in vivo, Lgl1-NMIIA and Lgl1-Par6-aPKCζ in different cellular compartments. We further showed that aPKCζ and NMIIA compete to bind directly to Lgl1 through the same domain. These data provide new insights into the role of Lgl1, NMIIA, and Par6-aPKCζ in establishing front-rear polarity in migrating cells. In this commentary, I discuss the role of Lgl1 in the regulation of the acto-NMII cytoskeleton and its regulation by the Par6-aPKCζ polarity complex, and how Lgl1 activity may contribute to the establishment of front-rear polarity in migrating cells.

  1. Initiation of migration and movement rates of Atlantic salmon smolts in fresh water

    Science.gov (United States)

    Stich, Daniel S.; Kinnison, Michael T.; Kocik, John F.; Zydlewski, Joseph

    2015-01-01

    Timing of ocean entry is critical for marine survival of both hatchery and wild Atlantic salmon (Salmo salar) smolts. Management practices and barriers to migration such as dams may constrain timing of smolt migrations resulting in suboptimal performance at saltwater entry. We modeled influences of stocking location, smolt development, and environmental conditions on (i) initiation of migration by hatchery-reared smolts and (ii) movement rate of hatchery- and wild-reared Atlantic salmon smolts in the Penobscot River, Maine, USA, from 2005 through 2014 using acoustic telemetry data. We also compared movement rates in free-flowing reaches with rates in reaches with hydropower dams and head ponds. We compared movement rates before and after (1) removal of two mainstem dams and (2) construction of new powerhouses. Initiation of movement by hatchery fish was influenced by smolt development, stocking location, and environmental conditions. Smolts with the greatest gill Na+, K+-ATPase (NKA) activity initiated migration 24 h sooner than fish with the lowest gill NKA activity. Fish with the greatest cumulative thermal experience initiated migration 5 days earlier than those with lowest cumulative thermal experience. Smolts released furthest from the ocean initiated migration earlier than those released downstream, but movement rate increased by fivefold closer to the ocean, indicating behavioral trade-offs between initiation and movement rate. Dams had a strong effect on movement rate. Movement rate increased from 2.8 to 5.4 km·h−1 in reaches where dams were removed, but decreased from 2.1 to 0.1 km·h−1 in reaches where new powerhouses were constructed. Movement rate varied throughout the migratory period and was inversely related to temperature. Fish moved slower at extreme high or low discharge. Responses in fish movement rates to dam removal indicate the potential scope of recovery for these activities.

  2. Flow and mass transfer downstream of an orifice under flow accelerated corrosion conditions

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Wael H., E-mail: ahmedw@kfupm.edu.sa [Department of Mechanical Engineering, King Fahd University of Petroleum and Minerals (KFUPM), P.O. Box 874, Dhahran 31261 (Saudi Arabia); Bello, Mufatiu M.; El Nakla, Meamer; Al Sarkhi, Abdelsalam [Department of Mechanical Engineering, King Fahd University of Petroleum and Minerals (KFUPM), P.O. Box 874, Dhahran 31261 (Saudi Arabia)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer Mass transfer downstream of orifices was numerically and experimentally investigated. Black-Right-Pointing-Pointer The surface wear pattern is measured and used to validate the present numerical results. Black-Right-Pointing-Pointer The maximum mass transfer coefficient found to occur at approximately 2-3 pipe diameters downstream of the orifice. Black-Right-Pointing-Pointer The FAC wear rates were correlated with the turbulence kinetic energy and wall mass transfer in terms of Sherwood number. Black-Right-Pointing-Pointer 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{sub 4}{center_dot} Vulgar-Fraction-One-Half H{sub 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

  3. Partial migration in fishes: causes and consequences

    DEFF Research Database (Denmark)

    Chapman, B.B.; Hulthén, K.; Brodersen, J.;

    2012-01-01

    migration are reflected upon: what ecological factors can shape the evolution of migratory dimorphism? How is partial migration maintained over evolutionary timescales? What proximate mechanisms determine whether an individual is migratory or remains resident? Following this, the consequences of partial...... with a reflection on the future opportunities in this field, and the avenues of research that are likely to be fruitful to shed light on the enduring puzzle of partial migration in fishes......Partial migration, where only some individuals from a population migrate, has been widely reported in a diverse range of animals. In this paper, what is known about the causes and consequences of partial migration in fishes is reviewed. Firstly, the ultimate and proximate drivers of partial...

  4. Efficient cell migration requires global chromatin condensation.

    Science.gov (United States)

    Gerlitz, Gabi; Bustin, Michael

    2010-07-01

    Cell migration is a fundamental process that is necessary for the development and survival of multicellular organisms. Here, we show that cell migration is contingent on global condensation of the chromatin fiber. Induction of directed cell migration by the scratch-wound assay leads to decreased DNaseI sensitivity, alterations in the chromatin binding of architectural proteins and elevated levels of H4K20me1, H3K27me3 and methylated DNA. All these global changes are indicative of increased chromatin condensation in response to induction of directed cell migration. Conversely, chromatin decondensation inhibited the rate of cell migration, in a transcription-independent manner. We suggest that global chromatin condensation facilitates nuclear movement and reshaping, which are important for cell migration. Our results support a role for the chromatin fiber that is distinct from its known functions in genetic processes.

  5. 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...

  6. Focal Adhesion-Independent Cell Migration.

    Science.gov (United States)

    Paluch, Ewa K; Aspalter, Irene M; Sixt, Michael

    2016-10-06

    Cell migration is central to a multitude of physiological processes, including embryonic development, immune surveillance, and wound healing, and deregulated migration is key to cancer dissemination. Decades of investigations have uncovered many of the molecular and physical mechanisms underlying cell migration. Together with protrusion extension and cell body retraction, adhesion to the substrate via specific focal adhesion points has long been considered an essential step in cell migration. Although this is true for cells moving on two-dimensional substrates, recent studies have demonstrated that focal adhesions are not required for cells moving in three dimensions, in which confinement is sufficient to maintain a cell in contact with its substrate. Here, we review the investigations that have led to challenging the requirement of specific adhesions for migration, discuss the physical mechanisms proposed for cell body translocation during focal adhesion-independent migration, and highlight the remaining open questions for the future.

  7. Study on ecological migration in Xinjiang, China

    Institute of Scientific and Technical Information of China (English)

    Abliz Yusup; Osman Niyaz

    2006-01-01

    This paper expounds on the meaning of migration and the status quo of studies at home and abroad on migration and ecological migration. It focuses on the discussion of the necessity of ecological migration in Xinjiang, and the problems faced by the ecological emigrants, such as the lack of water, the serious land salination and basification,sand storms, and the adaptation to the environment. Besides, it probes into the problems existing in the ecological migration, including the unscientific design of the moving project, the defects of the reclamation work, and the irrational treatment of the relation between ecological migration and regional development. Based on this, we put forward some suggestions about and countermeasures against those problems.

  8. Comment on "Effect of transferred NK4 gene on proliferation,migration, invasion, and apoptosis of human prostate cancer DU145 cells" by Dan Yue et al. in Asian Journal of Andrology

    Institute of Scientific and Technical Information of China (English)

    Shahriar Koochekpour

    2010-01-01

    @@ Hepatocyte growth factor/scatter factor (HGF/SF) interacting with its cell surface receptor tyrosine kinase (RTK) c-met proto-oncogene drives downstream signaling pathways which lead to cell proliferation, migration,invasion, apoptotic cell-death protection, angiogenesis during embryogenesis, repair and regeneration, and neoplastic growth and metastatic progression [1-6].

  9. Medical Assisting Program Guide.

    Science.gov (United States)

    Georgia Univ., Athens. Dept. of Vocational Education.

    This guide presents the standard curriculum for technical institutes in Georgia. The curriculum addresses the minimum competencies for a medical assisting program. The program guide is designed to relate primarily to the development of those skills needed by individuals in the medical assisting field, such as medical law and ethics, typing,…

  10. Migration and Education Inequality in Rural Mexico

    OpenAIRE

    David McKenzie; Hillel Rapoport

    2006-01-01

    This paper examines the impact of migration on education inequality in rural Mexico. Using data from the 1997 National Survey of Demographic Dynamics (ENADID), we first examine the impact of migration on educational attainment for males and females aged 12-15 and 16-18. We then build on the results on attainments to compute education inequality indicators for a large sample of communities throughout Mexico. After instrumenting, we find no significant impact of migration on educational attainm...

  11. Interregional Migration in Spain: A Semiparametric Analysis

    OpenAIRE

    Maza Fernández, Adolfo Jesús; Villaverde Castro, José

    2004-01-01

    This paper analyses the determinants of internal migration in Spain between 1995 and 2002. After a brief descriptive study, we present an analytical model of internal migration flows. Subsequently, we estimate this model by applying semiparametric techniques. The general conclusion that we come to is that net migration rates are influenced mainly by income and climatic condition differentials between the regions of origin and destination; in addition, unemployment and housin...

  12. Bayesian Probabilistic Projection of International Migration.

    Science.gov (United States)

    Azose, Jonathan J; Raftery, Adrian E

    2015-10-01

    We propose a method for obtaining joint probabilistic projections of migration for all countries, broken down by age and sex. Joint trajectories for all countries are constrained to satisfy the requirement of zero global net migration. We evaluate our model using out-of-sample validation and compare point projections to the projected migration rates from a persistence model similar to the method used in the United Nations' World Population Prospects, and also to a state-of-the-art gravity model.

  13. Cultural values in international migration and remittances

    OpenAIRE

    Inna Čábelková

    2014-01-01

    In this paper we study the effects of cultural determinants on the migration flows across countries and the financial flows back to the country of origin of the migrants in the form of remittances. We present econometric models for migration and remittances and test the relations between migration and remittances on one hand and cultural dimensions on the other hand. We find that collectivist countries produce more migrants per one inhabitant. This finding corresponds to social reason for mig...

  14. Guidance cue for cortical radial migration discovered

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ The regulatory mechanism for neuronal migration in the developing cortex is a major unsolved problem in developmental neurobiology. It is generally accepted that the migration of newborn pyramidal neurons from the ventricular zone toward upper cortical layers is guided by radial glial fibers in the developing cortex, and that the laminar structure of the cortex is formed through regulated attachment and detachment of migrating neurons with radial glial fibers.

  15. Mediating Migration: New Roles for (Mass) Media

    OpenAIRE

    Kosnick, Kira

    2014-01-01

    This article aims to expand the scope of studying media in relation to migration and diversity by addressing new forms of media deployment in the interest of regulating migration flows to the European Union and the United States. Beyond constructing representations of minorities and migration processes that impact interethnic relations and politics in countries of immigration, it is argued that media technologies and representations have new roles to play when it comes to targeting potential ...

  16. Monitoring of Downstream Salmon and Steelhead at Federal Hydroelectric Facilities, 1995 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Martinson, Rick D.; Graves, Richie J.; Langeslay, Michael J. (Northwest and Alaska Fisheries Science Center, Environmental and Technical Services Division, Portland, OR)

    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.

  17. Monitoring of Downstream Salmon and Steelhead at Federal Hydroelectric Facilities, 1996 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Martinson, Rick D.; Kamps, Jeffrey W.; Graves, Ritchie J. (Northwest and Alaska Fisheries Science Center, Fish Ecology Division, Seattle, WA)

    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.

  18. WHO IMMIGRATED TO TURKEY, WHERE THEY MIGRATE?

    Directory of Open Access Journals (Sweden)

    Kadir TEMURÇİN

    2013-04-01

    Full Text Available Migrations from Turkey to abroad for half a century have proceeded in the recent times by undergoing important changes. Moreover, it has been observed that there exist various types and ways of foreigner migration from abroad to Turkey which began from 1980 onwards and became clarified in the 2000s. This study is aimed to focus on who migrated from abroad to Turkey and where they migrated later on the basis of the 2000 General Census.As in the internal migration, the external migration tends towards the western part of the country, particularly big cities. Thusly, % 44 of the migration occurred in big cities; % 33.4 in the centre of towns and provinces; the rest % 22.5 in the countryside. The fact that % 51.9 of immigrants were born in Turkey gives rise to "comeback migration" thought with regard to the external migration. Moreover, that % 77.7 of them are Turkish nationals supports this judgment. On the other hand, the foreign nationals whose number has reached to 50.251 (% 21.5 are non-negligible. The big cities where the external nationals are grouped and the touristic centers on the Aegean and Mediterranean coasts are also the areas immigrants of foreign origin have settled down.

  19. 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.)

  20. 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.

  1. 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.

  2. Multiregional estimation of gross internal migration flows.

    Science.gov (United States)

    Foot, D K; Milne, W J

    1989-01-01

    "A multiregional model of gross internal migration flows is presented in this article. The interdependence of economic factors across all regions is recognized by imposing a non-stochastic adding-up constraint that requires total inmigration to equal total outmigration in each time period. An iterated system estimation technique is used to obtain asymptotically consistent and efficient parameter estimates. The model is estimated for gross migration flows among the Canadian provinces over the period 1962-86 and then is used to examine the likelihood of a wash-out effect in net migration models. The results indicate that previous approaches that use net migration equations may not always be empirically justified."

  3. 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)

  4. PIV Measurements of flow downstream of polyurethane heart valve prosthesis for artificial heart: steady flow experiment

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.K.; Sung, J.Y. [Seoul National University Graduate School, Seoul (Korea); Chang, J.K.; Yoo, J.Y.; Min, B.G. [Seoul National University, Seoul (Korea)

    1999-12-01

    Hemodynamic performance of a polyurethane heart valve prosthesis was evaluated in comparison with that of Bjork-Shiley Monostrut mechanical valve in steady flow representing the systolic peak flow phase. Pressure losses through the valves were obtained from the streamwise pressure distributions downstream of the valves. Unsteady and turbulent flow field distal to the heart valve prostheses were investigated using PIV(Particle Image Velocimetry) which can measure the full-field velocity instantaneously and noninvasively. By examining the velocity and Reynolds shear stress fields downstream of the polyurethane heart valve, it is known that there is a large recirculation region near the valve and high shear stress regions exist at the interface between strong axial jet flows along the wall and vortical flows in the central area. The possibilities of vascular complications, such as the thrombus formation and red blood cell damage, could be predicted from the overall view of the velocity and stress fields. (author). 22 refs., 9 figs., 1 tab.

  5. Electromagnetic field generation in the downstream of electrostatic shocks due to electron trapping

    CERN Document Server

    Stockem, A; Fonseca, R A; Silva, L O

    2014-01-01

    A new magnetic field generation mechanism in electrostatic shocks is found, which can produce fields with magnetic energy density as high as 0.01 of the kinetic energy density of the flows on time scales $ \\tilde \\, 10^4 \\, {\\omega}_{pe}^{-1}$. Electron trapping during the shock formation process creates a strong temperature anisotropy in the distribution function, giving rise to the pure Weibel instability. The generated magnetic field is well-confined to the downstream region of the electrostatic shock. The shock formation process is not modified and the features of the shock front responsible for ion acceleration, which are currently probed in laser-plasma laboratory experiments, are maintained. However, such a strong magnetic field determines the particle trajectories downstream and has the potential to modify the signatures of the collisionless shock.

  6. Effects of Flaming Gorge Dam hydropower operations on downstream flow, stage, and sediment transport

    Energy Technology Data Exchange (ETDEWEB)

    Yin, S.C.L.; Tomasko, D.; Cho, H.E.; Williams, G. [Argonne National Lab., IL (United States); McCoy, J.; Palmer, C. [USDOE Western Area Power Administration, Salt Lake City, UT (United States)

    1996-11-01

    Hydropower operations at Flaming Gorge Dam, located on the Green River in Utah, can produce rapid downstream changes in flow and stage. These changes can in turn affect sediment transport and ecologic resources below the dam. To evaluate these effects, four hydropower operational scenarios with varying degrees of hydropower-release fluctuations were examined. This study demonstrates that the combined use of river-flow routing, water-surface profile, and sediment-transport models can provide useful information for evaluating the potential impacts of hydropower-operations on ecological and other resources downstream of the dam. Study results show that flow fluctuations may or may not persist for a long distance, depending on the initial magnitude of fluctuation and the duration of hydropower peaking. Stage fluctuations depend not only on flow fluctuations but also on river channel characteristics, such as channel width and longitudinal slope.

  7. Reorganization of Coherent Structures Downstream a Circular Cylinder Located between Two Parallel Walls

    Directory of Open Access Journals (Sweden)

    F. Rehimi

    2011-01-01

    Full Text Available Experiments were performed at low Reynolds numbers in the range 75 Re 275 in the wake of a circular cylinder of dc diameter placed symmetrically between two parallel walls of H height. 2D2C particle image velocimetry (PIV was used to investigate the flow downstream the cylinder. In the unsteady flow regime downstream the cylinder, the detached primary vortices (Pi interact with walls generating secondary ones (Pi’ and modify the cylinder wake dynamic. The kinematical properties (advection velocity, circulation, rotation kinetic energy, etc. of the generated secondary vortices are studied and compared with the primary ones in order to show how the walls influence the von Kármán vortex street. The authors propose here a relation between the circulations and kinetic energies of primary and secondary vortices.

  8. The use of Reverse Micelles in Downstream Processing of Biotechnological Products

    CERN Document Server

    Lee, Kai Lun

    2011-01-01

    This paper aims to discuss the use of reverse micelles in downstream processing of biotechnological products. The interest in this technology is piqued firstly by various advantages of a liquid-liquid extraction process, among which are cost effectiveness, and ease of scaling up and implementing a continuous process for whole broth processing. The use of reverse micelles is thought to be among the most promising due to the high efficiency and selectivity being achieved in some systems. However, there are various issues that have impeded the widespread use of reverse micelles such as the identification and development of suitable surfactants and ligands; as well as difficulties in the back extraction process. These issues, as well as latest developments and applications of reverse micelles in downstream processing of biotechnological products will be discussed in this paper.

  9. Arabidopsis NAC1 transduces auxin signal downstream of TIR1 to promote lateral root development.

    Science.gov (United States)

    Xie, Q; Frugis, G; Colgan, D; Chua, N H

    2000-12-01

    Auxin plays a key role in lateral root formation, but the signaling pathway for this process is poorly understood. We show here that NAC1, a new member of the NAC family, is induced by auxin and mediates auxin signaling to promote lateral root development. NAC1 is a transcription activator consisting of an N-terminal conserved NAC-domain that binds to DNA and a C-terminal activation domain. This factor activates the expression of two downstream auxin-responsive genes, DBP and AIR3. Transgenic plants expressing sense or antisense NAC1 cDNA show an increase or reduction of lateral roots, respectively. Finally, TIR1-induced lateral root development is blocked by expression of antisense NAC1 cDNA, and NAC1 overexpression can restore lateral root formation in the auxin-response mutant tir1, indicating that NAC1 acts downstream of TIR1.

  10. Capture of white sturgeon larvae downstream of The Dalles Dam, Columbia River, Oregon and Washington, 2012

    Science.gov (United States)

    Parsley, Michael J.; Kofoot, Eric

    2013-01-01

    Wild-spawned white sturgeon (Acipenser transmontanus) larvae captured and reared in aquaculture facilities and subsequently released, are increasingly being used in sturgeon restoration programs in the Columbia River Basin. A reconnaissance study was conducted to determine where to deploy nets to capture white sturgeon larvae downstream of a known white sturgeon spawning area. As a result of the study, 103 white sturgeon larvae and 5 newly hatched free-swimming embryos were captured at 3 of 5 reconnaissance netting sites. The netting, conducted downstream of The Dalles Dam on the Columbia River during June 25–29, 2012, provided information for potentially implementing full-scale collection efforts of large numbers of larvae for rearing in aquaculture facilities and for subsequent release at a larger size in white sturgeon restoration programs.

  11. Turbulent jet flow generated downstream of a low temperature dielectric barrier atmospheric pressure plasma device

    Science.gov (United States)

    Whalley, Richard D.; Walsh, James L.

    2016-08-01

    Flowing low temperature atmospheric pressure plasma devices have been used in many technological applications ranging from energy efficient combustion through to wound healing and cancer therapy. The generation of the plasma causes a sudden onset of turbulence in the inhomogeneous axisymmetric jet flow downstream of the plasma plume. The mean turbulent velocity fields are shown to be self-similar and independent of the applied voltage used to generate the plasma. It is proposed that the production of turbulence is related to a combination of the small-amplitude plasma induced body forces and gas heating causing perturbations in the unstable shear layers at the jet exit which grow as they move downstream, creating turbulence.

  12. 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).

  13. Downstream management practices of transnational companies in institutionally vulnerable countries: Export and use of hazardous products

    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...... 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...... 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...

  14. 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.

  15. 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.

  16. Turbulent jet flow generated downstream of a low temperature dielectric barrier atmospheric pressure plasma device.

    Science.gov (United States)

    Whalley, Richard D; Walsh, James L

    2016-08-26

    Flowing low temperature atmospheric pressure plasma devices have been used in many technological applications ranging from energy efficient combustion through to wound healing and cancer therapy. The generation of the plasma causes a sudden onset of turbulence in the inhomogeneous axisymmetric jet flow downstream of the plasma plume. The mean turbulent velocity fields are shown to be self-similar and independent of the applied voltage used to generate the plasma. It is proposed that the production of turbulence is related to a combination of the small-amplitude plasma induced body forces and gas heating causing perturbations in the unstable shear layers at the jet exit which grow as they move downstream, creating turbulence.

  17. Novel mechanism for gonadotropin-releasing hormone neuronal migration involving Gas6/Ark signaling to p38 mitogen-activated protein kinase.

    Science.gov (United States)

    Allen, Melissa P; Linseman, Daniel A; Udo, Hiroshi; Xu, Mei; Schaack, Jerome B; Varnum, Brian; Kandel, Eric R; Heidenreich, Kim A; Wierman, Margaret E

    2002-01-01

    Gonadotropin-releasing hormone (GnRH) is the central regulator of the reproductive axis. Normal sexual maturation depends on the migration of GnRH neurons from the olfactory placode to the hypothalamus during development. Previously, we showed restricted expression of the membrane receptor adhesion-related kinase (Ark) in immortalized cell lines derived from migratory but not postmigratory GnRH neurons. In addition, Ark and GnRH transcripts were detected along the GnRH neuron migratory route in the E13 mouse cribriform plate. In the present study, we examined the role of Ark and its ligand, Gas6 (encoded by growth arrest-specific gene 6), in GnRH neuron migration. Gas6 stimulated lamellipodial extension, membrane ruffling, and chemotaxis of immortalized NLT GnRH neuronal cells via the Ark receptor. Gas6/Ark signaling promoted activation of the Rho family GTPase Rac, and adenoviral-mediated expression of dominant negative N17Rac abolished Gas6/Ark-induced actin cytoskeletal reorganization and migration of GnRH neuronal cells. In addition, p38 MAPK was activated downstream of Ark and Rac, and inhibition of p38 MAPK with either SB203580 or adenoviral dominant negative p38alpha also blocked Gas6/Ark-mediated migration. Finally, downstream of Rac and p38 mitogen-activated protein kinase (MAPK), Gas6/Ark signaling promoted activation of MAPK-activated protein kinase 2 and induced phosphorylation of HSP25, a known regulator of cortical actin remodeling. The data are the first to demonstrate a migratory signaling pathway downstream of Ark/Axl family receptors and suggest a previously unidentified role for p38 MAPK in neuronal migration. Furthermore, these studies support a potential role for Ark in the regulation of GnRH neuronal migration.

  18. Experimental Investigation of Two Interacting Thruster-Plumes Downstream of the Nozzles

    OpenAIRE

    Holz, André; Dettleff, Georg; Hannemann, Klaus; Ziegenhagen, Stefan

    2012-01-01

    The plume-plume interaction of two small cold gas thrusters is investigated under high vacuum conditions in the DLR high vacuum plume test facility STG-CT. In this paper we concentrate on the interaction downstream of the nozzles. After introducing the experimental equipment, characteristics of shock interaction are presented. Furthermore the appropriateness of the Penetration Knudsen Number for predicting the type of interaction also for thruster plumes is investigated.

  19. Coexistence of up- and downstream traffic waves on a ring road

    Science.gov (United States)

    van der Weele, K.; Kanellopoulos, G.

    2016-09-01

    It is an observational fact that density waves in vehicle traffic can move in either direction: small-amplitude waves travel in the same direction as the cars (downstream) whereas high-amplitude waves or "jams" travel in the opposite direction (upstream). We construct a model of ring road traffic to demonstrate how this comes about. Our model shows the spontaneous generation of these density waves, explains their stability properties, and pinpoints the precise density level at which the wave speed changes direction.

  20. Downstream approaches to phosphorus management in agricultural landscapes: regional applicability and use.

    Science.gov (United States)

    Kröger, R; Dunne, E J; Novak, J; King, K W; McLellan, E; Smith, D R; Strock, J; Boomer, K; Tomer, M; Noe, G B

    2013-01-01

    This review provides a critical overview of conservation practices that are aimed at improving water quality by retaining phosphorus (P) downstream of runoff genesis. The review is structured around specific downstream practices that are prevalent in various parts of the United States. Specific practices that we discuss include the use of controlled drainage, chemical treatment of waters and soils, receiving ditch management, and wetlands. The review also focuses on the specific hydrology and biogeochemistry associated with each of those practices. The practices are structured sequentially along flowpaths as you move through the landscape, from the edge-of-field, to adjacent aquatic systems, and ultimately to downstream P retention. Often practices are region specific based on geology, cropping practices, and specific P related problems and thus require a right practice, and right place mentality to management. Each practice has fundamental P transport and retention processes by systems that can be optimized by management with the goal of reducing downstream P loading after P has left agricultural fields. The management of P requires a system-wide assessment of the stability of P in different biogeochemical forms (particulate vs. dissolved, organic vs. inorganic), in different storage pools (soil, sediment, streams etc.), and under varying biogeochemical and hydrological conditions that act to convert P from one form to another and promote its retention in or transport out of different landscape components. There is significant potential of hierarchically placing practices in the agricultural landscape and enhancing the associated P mitigation. But an understanding is needed of short- and long-term P retention mechanisms within a certain practice and incorporating maintenance schedules if necessary to improve P retention times and minimize exceeding retention capacity.

  1. Drosophila Fascin is a novel downstream target of prostaglandin signaling during actin remodeling

    OpenAIRE

    Groen, Christopher M.; Spracklen, Andrew J.; Fagan, Tiffany N.; Tootle, Tina L.

    2012-01-01

    Although prostaglandins (PGs)—lipid signals produced downstream of cyclooxygenase (COX) enzymes—regulate actin cytoskeletal dynamics, their mechanisms of action are unknown. We previously established Drosophila oogenesis, in particular nurse cell dumping, as a new model to determine how PGs regulate actin remodeling. PGs, and thus the Drosophila COX-like enzyme Pxt, are required for both the parallel actin filament bundle formation and the cortical actin strengthening required for dumping. He...

  2. Downstream Regulatory Element Antagonist Modulator (DREAM), a target for anti-thrombotic agents.

    Science.gov (United States)

    Cho, Jaehyung

    2017-03-01

    Circulating platelets participate in the process of numerous diseases including thrombosis, inflammation, and cancer. Thus, it is of great importance to understand the underlying mechanisms mediating platelet activation under disease conditions. Emerging evidence indicates that despite the lack of a nucleus, platelets possess molecules that are involved in gene transcription in nucleated cells. This review will summarize downstream regulatory element antagonist modulator (DREAM), a transcriptional repressor, and highlight recent findings suggesting its novel non-transcriptional role in hemostasis and thrombosis.

  3. The study of glycerol-based fermentation and broth downstream by nanofiltration

    Directory of Open Access Journals (Sweden)

    Gryta Marek

    2014-12-01

    Full Text Available In this work, the glycerol fermentation was carried out using Citrobacter freundii bacteria. The influence of glycerol and metabolites concentrations, and the pH changes on the efficiency of 1,3-propanediol production, during batch and fed-batch processes, was presented. The nanofiltration was used for the separation of obtained post-fermentation solutions. The resulted 1,3-PD solutions were significantly desalted, which may facilitate further downstream processes during 1,3-PD production.

  4. Coil Migration through a Neuroform 3 Stent during Endovascular Coiling. A Case Report.

    LENUS (Irish Health Repository)

    O'Hare, A

    2009-07-29

    Summary: A 43-year-old woman attended for stent assisted coiling. A Neuroform 30 x 4.5 mm stent had been successfully placed over the left periophthalmic aneurysm. During the coiling the first coil migrated through the crowns in the stent, lodging at the MCA bifurcation. We believe that the coil herniated through the overlying stent due to the carotid siphon curvature and the open cell design. Furthermore the distal markers of the stent impeded coil extraction with a MERCI device.

  5. From migration to settlement: the pathways, migration modes and dynamics of neurons in the developing brain.

    Science.gov (United States)

    Hatanaka, Yumiko; Zhu, Yan; Torigoe, Makio; Kita, Yoshiaki; Murakami, Fujio

    2016-01-01

    Neuronal migration is crucial for the construction of the nervous system. To reach their correct destination, migrating neurons choose pathways using physical substrates and chemical cues of either diffusible or non-diffusible nature. Migrating neurons extend a leading and a trailing process. The leading process, which extends in the direction of migration, determines navigation, in particular when a neuron changes its direction of migration. While most neurons simply migrate radially, certain neurons switch their mode of migration between radial and tangential, with the latter allowing migration to destinations far from the neurons' site of generation. Consequently, neurons with distinct origins are intermingled, which results in intricate neuronal architectures and connectivities and provides an important basis for higher brain function. The trailing process, in contrast, contributes to the late stage of development by turning into the axon, thus contributing to the formation of neuronal circuits.

  6. Characterization of sequences downstream from transcriptional start site of Rhizobium meliloti nifHDK promoter

    Institute of Scientific and Technical Information of China (English)

    高云峰; 吴桐; 朱家璧; 俞冠翘; 沈善炯

    1997-01-01

    In free-living state, the nifHDK promoter P1 of Rhizobium meliloti is induced in response to mi-croaerobiosis and expressed to a high level, while the fixABCX promoter P2 is not. The sequences upstream from both P1 and P2 share extended homology (about 85% ), which are about 160 bp in length, but the sequences downstream of the respective transcriptional start site are different. When the downstream sequence (DS) of P2 was replaced by the corresponding fragment from+ 17 to + 61 of P1, the expression of P2 is greatly increased under free-living condi-tion by lowering the oxygen tension, and the activity of P2 promoter can also be significantly enhanced in E. coli by the NifA protein. The difference between the DS regions of P1 and P2 promoter resulted in different expressions of P1 and P2 promoter under free-living microaerobic condition and in E. coli. The expression of P2 does not depend on the downstream sequences from the promoter element during symbiosis. Primer extension experiments identified the

  7. MicroRNA-145 suppresses hepatocellular carcinoma by targeting IRS1 and its downstream Akt signaling

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yelin [Department of Anesthesiology, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou (China); Key Laboratory of Combined Multi-organ Transplantation, Ministry of Public Health, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou (China); Hu, Chen; Cheng, Jun [Department of Surgery, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou (China); Key Laboratory of Combined Multi-organ Transplantation, Ministry of Public Health, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou (China); Chen, Binquan [Department of Anesthesiology, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou (China); Ke, Qinghong; Lv, Zhen; Wu, Jian [Department of Surgery, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou (China); Key Laboratory of Combined Multi-organ Transplantation, Ministry of Public Health, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou (China); Zhou, Yanfeng, E-mail: zyfhdj@yahoo.com [Department of Anesthesiology, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou (China)

    2014-04-18

    Highlights: • MiR-145 expression is down-regulated in HCC tissues and inversely related with IRS1 levels. • MiR-145 directly targets IRS1 in HCC cells. • Restored expression of miR-145 suppressed HCC cell proliferation and growth. • MiR-145 induced IRS1 under-expression potentially reduced downstream AKT signaling. - Abstract: Accumulating evidences have proved that dysregulation of microRNAs (miRNAs) is involved in cancer initiation and progression. In this study, we showed that miRNA-145 level was significantly decreased in hepatocellular cancer (HCC) tissues and cell lines, and its low expression was inversely associated with the abundance of insulin receptor substrate 1 (IRS1), a key mediator in oncogenic insulin-like growth factor (IGF) signaling. We verified IRS1 as a direct target of miR-145 using Western blotting and luciferase reporter assay. Further, the restoration of miR-145 in HCC cell lines suppressed cancer cell growth, owing to down-regulated IRS1 expression and its downstream Akt/FOXO1 signaling. Our results demonstrated that miR-145 could inhibit HCC through targeting IRS1 and its downstream signaling, implicating the loss of miR-145 regulation may be a potential molecular mechanism causing aberrant oncogenic signaling in HCC.

  8. Detection, Validation, and Downstream Analysis of Allelic Variation in Gene Expression

    Science.gov (United States)

    Ciobanu, Daniel C.; Lu, Lu; Mozhui, Khyobeni; Wang, Xusheng; Jagalur, Manjunatha; Morris, John A.; Taylor, William L.; Dietz, Klaus; Simon, Perikles; Williams, Robert W.

    2010-01-01

    Common sequence variants within a gene often generate important differences in expression of corresponding mRNAs. This high level of local (allelic) control—or cis modulation—rivals that produced by gene targeting, but expression is titrated finely over a range of levels. We are interested in exploiting this allelic variation to study gene function and downstream consequences of differences in expression dosage. We have used several bioinformatics and molecular approaches to estimate error rates in the discovery of cis modulation and to analyze some of the biological and technical confounds that contribute to the variation in gene expression profiling. Our analysis of SNPs and alternative transcripts, combined with eQTL maps and selective gene resequencing, revealed that between 17 and 25% of apparent cis modulation is caused by SNPs that overlap probes rather than by genuine quantitative differences in mRNA levels. This estimate climbs to 40–50% when qualitative differences between isoform variants are included. We have developed an analytical approach to filter differences in expression and improve the yield of genuine cis-modulated transcripts to ∼80%. This improvement is important because the resulting variation can be successfully used to study downstream consequences of altered expression on higher-order phenotypes. Using a systems genetics approach we show that two validated cis-modulated genes, Stk25 and Rasd2, are likely to control expression of downstream targets and affect disease susceptibility. PMID:19884314

  9. Downstream hydraulic geometry relationships: Gathering reference reach-scale width values from LiDAR

    Science.gov (United States)

    Sofia, G.; Tarolli, P.; Cazorzi, F.; Dalla Fontana, G.

    2015-12-01

    This paper examines the ability of LiDAR topography to provide reach-scale width values for the analysis of downstream hydraulic geometry relationships along some streams in the Dolomites (northern Italy). Multiple reach-scale dimensions can provide representative geometries and statistics characterising the longitudinal variability in the channel, improving the understanding of geomorphic processes across networks. Starting from the minimum curvature derived from a LiDAR DTM, the proposed algorithm uses a statistical approach for the identification of the scale of analysis, and for the automatic characterisation of reach-scale bankfull widths. The downstream adjustment in channel morphology is then related to flow parameters (drainage area and stream power). With the correct planning of a LiDAR survey, uncertainties in the procedure are principally due to the resolution of the DTM. The outputs are in general comparable in quality to field survey measurements, and the procedure allows the quick comparison among different watersheds. The proposed automatic approach could improve knowledge about river systems with highly variable widths, and about systems in areas covered by vegetation or inaccessible to field surveys. With proven effectiveness, this research could offer an interesting starting point for the analysis of differences between watersheds, and to improve knowledge about downstream channel adjustment in relation, for example, to scale and landscape forcing (e.g. sediment transport, tectonics, lithology, climate, geomorphology, and anthropic pressure).

  10. Measurement of pulsatile turbulent flow downstream of polyurethane heart valve prosthesis using particle image velocimetry

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.K.; Sung, J.Y. [Graduate School, Seoul National University, Seoul (Korea); Chang, J.K.; Min, B.G.; Yoo, J.Y. [Seoul National University, Seoul (Korea)

    1998-11-01

    In-vitro flow characteristics downstream of a polyurethane artificial heart valve under a pulsatile flow condition were investigated using Particle Image Velocimetry (PIV). With a triggering system and a time-delay circuit the velocity field downstream of the valve was evaluated in conjunction with the opening behavior of a flexible valve leaflet during a cardiac cycle.. Reynolds shear stress distribution was calculated from the velocity fields at a peak systolic phase. Direct measurements of the wall shear stress by hot-film anemometry (HFA) were compared with the PIV data. The possibilities of vascular complications, such as the thrombus formation and red blood cell damage, could be estimated from the overall view of the instantaneous velocity and stress fields obtained. A correlation between the flow pattern downstream of the valve and the corresponding opening posture of the polyurethane valve membrane gives useful data necessary for the improved design of the frame structure and leaflet geometry of the valve. (author). 11 refs., 8 figs., 5 tabs.

  11. Assessing water deprivation at the sub-river basin scale in LCA integrating downstream cascade effects.

    Science.gov (United States)

    Loubet, Philippe; Roux, Philippe; Núñez, Montserrat; Belaud, Gilles; Bellon-Maurel, Véronique

    2013-12-17

    Physical water deprivation at the midpoint level is assessed in water-related LCIA methods using water scarcity indicators (e.g., withdrawal-to-availability and consumption-to-availability) at the river basin scale. Although these indicators represent a great step forward in the assessment of water-use-related impacts in LCA, significant challenges still remain in improving their accuracy and relevance. This paper presents a methodology that can be used to derive midpoint characterization factors for water deprivation taking into account downstream cascade effects within a single river basin. This effect is considered at a finer scale because a river basin must be split into different subunits. The proposed framework is based on a two-step approach. First, water scarcity is defined at the sub-river basin scale with the consumption-to-availability (CTA) ratio, and second, characterization factors for water deprivation (CFWD) are calculated, integrating the effects on downstream sub-river basins. The sub-river basin CTA and CFWD were computed based on runoff data, water consumption data and a water balance for two different river basins. The results show significant differences between the CFWD in a given river basin, depending on the upstream or downstream position. Finally, an illustrative example is presented, in which different land planning scenarios, taking into account additional water consumption in a city, are assessed. Our work demonstrates how crucial it is to localize the withdrawal and release positions within a river basin.

  12. Safety of snake antivenom immunoglobulins: efficacy of viral inactivation in a complete downstream process.

    Science.gov (United States)

    Caricati, C P; Oliveira-Nascimento, L; Yoshida, J T; Caricati, A T P; Raw, I; Stephano, M A

    2013-01-01

    Viral safety remains a challenge when processing a plasma-derived product. A variety of pathogens might be present in the starting material, which requires a downstream process capable of broad viral reduction. In this article, we used a wide panel of viruses to assess viral removal/inactivation of our downstream process for Snake Antivenom Immunoglobulin (SAI). First, we screened and excluded equine plasma that cross-reacted with any model virus, a procedure not published before for antivenoms. In addition, we evaluated for the first time the virucidal capacity of phenol applied to SAI products. Among the steps analyzed in the process, phenol addition was the most effective one, followed by heat, caprylic acid, and pepsin. All viruses were fully inactivated only by phenol treatment; heat, the second most effective step, did not inactivate the rotavirus and the adenovirus used. We therefore present a SAI downstream method that is cost-effective and eliminates viruses to the extent required by WHO for a safe product.

  13. Upstream to downstream: stormwater quality in Mayagüez, Puerto Rico.

    Science.gov (United States)

    Wengrove, Meagan E; Ballestero, Thomas P

    2012-08-01

    The focus of this research was upon consequences of urban stormwater runoff entering two streams in Mayagüez, Puerto Rico. Mayagüez is the largest urban area of the western side of the island of Puerto Rico and provides an excellent point of reference to monitor the affects of urban development on water quality in a tropical climate. The two monitored streams were Quebrada del Oro and Cano Majagual. The research hypothesis asks, "Does stormwater runoff from urban development measurably affect the water quality of downstream receiving water by raising the conductivity, temperature, and flow quantity characteristics during storm events in comparison to upstream water quality?" In essence, the results for Quebrada del Oro agreed with the hypothesis of this project, while Cano Majagual produced results different from the hypothesis primarily due to the absence of non-urbanized land use for both upstream and downstream sections as well as the buffering capacity of a large wetland just upstream of the downstream instrument location of Cano Majagual. Both streams showed signs of stream impairment according to the temperature criteria (32°C or 90°F) set by the Junta de Calidad Ambiental and the US Environmental Protection Agency. Dissolved oxygen levels of the streams were severely affected by water temperature and oxygen-consuming matter within these stream systems, making dissolved oxygen and temperature important water quality parameters for tropical climates.

  14. Downstream passage of fish larvae and eggs through a small-sized reservoir, Mucuri river, Brazil

    Directory of Open Access Journals (Sweden)

    Paulo S. Pompeu

    2011-12-01

    Full Text Available In South America, one important symptom of the failure of fish passages to sustain fish migratory recruitment is the inability of eggs and larvae to reach the nurseries. This is especially so when the breeding areas are located upstream of a reservoir, and the floodplain is downstream of the dam. Therefore, the transport of fish larvae and eggs across reservoir barriers is a key factor in the development of effective conservation strategies. In this paper, we evaluate the potential for migratory fish larvae and egg transportation across a small size reservoir in eastern Brazil. We sampled fish daily between 15th October 2002 and 15th February 2003 (spawning period in the Mucuri River, immediately upstream of the reservoir and downstream of the Santa Clara Power Plant dam. Our study was the first to indicate the possibility of successful larval passage through the reservoir of a hydroelectric reservoir and dam in South America, and showed that the passage of migratory fish larvae was associated significantly with residence time of water in the reservoir. The relatively short water residence time and elevated turbidity of the Santa Clara's reservoir waters during the rainy season certainly contributed to the successful passage, and can be considered as key factors for a priori evaluations of the feasibility of a downstream larval passage.

  15. Optimizing withdrawal from drinking water reservoirs to reduce downstream temperature pollution and reservoir hypoxia.

    Science.gov (United States)

    Weber, M; Rinke, K; Hipsey, M R; Boehrer, B

    2017-03-20

    Sustainable management of drinking water reservoirs requires balancing the demands of water supply whilst minimizing environmental impact. This study numerically simulates the effect of an improved withdrawal scheme designed to alleviate the temperature pollution downstream of a reservoir. The aim was to identify an optimal withdrawal strategy such that water of a desirable discharge temperature can be supplied downstream without leading to unacceptably low oxygen concentrations within the reservoir. First, we calibrated a one-dimensional numerical model for hydrodynamics and oxygen dynamics (GLM-AED2), verifying that the model reproduced water temperatures and hypolimnetic dissolved oxygen concentrations accurately over a 5 year period. Second, the model was extended to include an adaptive withdrawal functionality, allowing for a prescribed withdrawal temperature to be found, with the potential constraint of hypolimnetic oxygen concentration. Scenario simulations on epi-/metalimnetic withdrawal demonstrate that the model is able to autonomously determine the best withdrawal height depending on the thermal structure and the hypolimnetic oxygen concentration thereby optimizing the ability to supply a desirable discharge temperature to the downstream river during summer. This new withdrawal strategy also increased the hypolimnetic raw water volume to be used for drinking water supply, but reduced the dissolved oxygen concentrations in the deep and cold water layers (hypolimnion). Implications of the results for reservoir management are discussed and the numerical model is provided for operators as a simple and efficient tool for optimizing the withdrawal strategy within different reservoir contexts.

  16. On the electron temperature downstream of the solar wind termination shock

    Energy Technology Data Exchange (ETDEWEB)

    Chashei, I.V. [Lebedev Physical Institute, Moscow (Russian Federation); Fahr, H.J. [Bonn Univ. (Germany). Argelander Inst. fuer Astronomie

    2013-09-01

    In this paper we study the temperatures of electrons convected with the solar wind to large solar distances and finally transported over the solar wind termination shock. Nearly nothing, unless at high energies in the cosmic ray regime, is known about the thermodynamical behaviour of these distant electrons from in situ plasma observations. Hence it is tacitly assumed these electrons, due to their adiabatic behaviour and vanishing heat conduction or energization processes, have rapidly cooled off to very low temperatures once they eventually arrive at the solar wind termination shock (at about 100 AU). In this paper we show that such electrons, however, at their passage over the termination shock due to the shock-electric field action undergo an overadiabatic heating and therefore appear on the downstream side as a substantially heated plasma species. Looking quantitatively into this heating process we find that solar wind electrons achieve temperatures of the order of 2-4 x 10{sup 6} K downstream of the termination shock, depending on the upstream solar wind bulk velocity and the shock compression ratio. Hence these electrons therewith play an important dynamical role in structuring this shock and determining the downstream plasma flow properties. Furthermore, they present an additional ionization source for incoming neutral interstellar hydrogen and excite X-ray emission. They also behave similar to cosmic ray electrons and extend to some limited region upstream of the shock of the order of 0.1 AU by spatial diffusion and thereby also modify the upstream solar wind properties. (orig.)

  17. Improved light-transmission method for the study of LNAPL migration and distribution rule.

    Science.gov (United States)

    Zhao, Yongsheng; Sun, Jiaqiang; Sun, Chao; Cui, Jian; Zhou, Rui

    2015-01-01

    In this study, diesel was selected as a pollutant to study the migration and distribution rule of light non-aqueous phase liquid (LNAPL) in the simulated vadose zone. Saturation was regarded as a critical parameter to reflect the LNAPL migration and distribution rule. To get LNAPL saturation distribution figures, an image processing method of saturation was established to improve light-transmission technology, which can deal with digital camera images. Results showed that the vadose zone contains three areas from top to bottom, named dry media, transition zone and capillary zone. The system has two interfaces at which moisture content increased significantly. The significant increase in moisture content induced two apparent horizontal LNAPL diffusions in the two interfaces. Furthermore, the highly saturated LNAPL was mostly distributed near the wet interface, which lay between the dry media and the transition zone. Moreover, the downstream expansion of LNAPL in the capillary zone was promoted by groundwater flow, yet cutting off LNAPL supply could stop the downstream expansion after a period of time. The accuracy of this image processing method of saturation was verified by mass balance theory and reported a relative error of 4.38%.

  18. Chasing waterfalls: Experimental controls on knickpoint form and migration processes

    Science.gov (United States)

    Baynes, Edwin; Lague, Dimitri; Attal, Mikael

    2016-04-01

    As the link between the fluvial network and hillslopes, bedrock channels mediate the response of the landscape to changing boundary conditions, such as tectonics and climate. Such signals of transient forcing are manifested in bedrock river profiles through migrating 'knickzones' or 'knickpoints', that separate a downstream reach broadly in equilibrium with the new conditions and an upstream reach which is yet to adjust. Knickpoints therefore mark a dynamic boundary location within mountain landscapes, yet the complexities of the mechanisms of knickpoint retreat are often ignored in studies of landscape evolution. We carried out a series of box flume experiments (65 cm long, 30 cm wide) to explore the importance of knickpoint geometry, mean discharge and substrate strength on the form and migration of knickpoints in a cohesive homogenous substrate. The retreat rate of knickpoints is found to be independent of mean discharge. Knickpoints retreat faster through a weaker substrate. The dominant control on knickpoint retreat, when discharge and substrate strength are constant, is the knickpoint form which is set by the ratio of channel flow depth to knickpoint height. Where the knickpoint height is five times greater than the flow depth, the knickpoints develop undercutting plunge pools, accelerating the removal of material from the knickpoint base and the overall retreat rate, possibly due to the trajectory of the jet at the knickpoint lip. Smaller knickpoints relative to the flow depth are more likely to diffuse from a vertical step into a steepened reach or completely as the knickpoint retreats up channel. These experiments challenge the established assumption in models of landscape evolution that a simple relationship exists between knickpoint retreat rate and discharge/drainage area. In order to fully understand how bedrock channels, and thus mountain landscapes, respond to transient forcing, further detailed study of the mechanics of erosion processes at

  19. Working and Living Conditions of Migrant Workers in the GCC: India Migration Report 2016: Gulf Migration

    OpenAIRE

    Diop, Abdoulaye; Le, Kien T.; Ewers, Michael; S. Irudaya Rajan

    2016-01-01

    India Migration Report 2016 discusses migration to the Persian Gulf region. This volume: • looks at contemporary labour recruitment and policy, both in India and in the Gulf Cooperation Council (GCC) countries; • explores gender issues in migration to Gulf countries; and • brings together latest field data on migrants across states in India. Part of the prestigious annual series, this volume will interest scholars and researchers of economics, development studies, migration an...

  20. EMPIRICAL REFLECTIONS ON MIGRATION PHENOMENON. MAJOR EFFECTS OF MIGRATION ON THE HUMAN CAPITAL

    OpenAIRE

    Simona BUTA; Rozalia Iuliana KICSI

    2013-01-01

    The paper Empirical reflections on migration phenomenon. Major effects of migration on the human capital analyzes the migration flows of the workforce (as part of the human capital) globally/regionally, especially the highly qualified workforce migration. The qualified manpower processes of attracting on the work market have not been always well understood and, in some cases, have generated a series of difficulties. This is the reason why we will focus on the „waste of brains” phenomenon, whi...

  1. Complex biallelic IGH rearrangements in IgM-expressing Z-138 cell line : Involvement of downstream immunoglobulin class switch recombination

    NARCIS (Netherlands)

    Guikema, JEJ; Fenton, JAL; de Boer, C; Kleiverda, K; Brink, AATP; Raap, AK; Estrov, Z; Schuuring, E; Kluin, PM

    2005-01-01

    Chromosomal translocations involving the immunoglobulin (Ig) receptor loci usually disrupt and silence these loci. On the basis of observations in follicular lymphoma (FL) with downstream Ig heavy chain (IGH) class switch recombination (CSR), we hypothesized that downstream CSR-mediated chromosomal

  2. FEMA Hazard Mitigation Assistance Flood Mitigation Assistance (FMA) Data

    Data.gov (United States)

    Department of Homeland Security — This dataset contains closed and obligated projects funded under the following Hazard Mitigation Assistance (HMA) grant programs: Flood Mitigation Assistance (FMA)....

  3. EFFECT OF GANGES RIVER MORPHOLOGICAL DYNAMICS AND FARAKKA BARRAGE ON UPWARD MIGRATION AND CATCH OF INDIAN SHAD (TENUALOSA ILISHA) IN BANGLADESH

    DEFF Research Database (Denmark)

    Ahsan, Dewan; Faruque, Hasan; Sarker, HM

    2016-01-01

    becoming a threatened species due to human intervention and climatic factors. This study is aimed to assess the impact of the Farakka barrage and the Ganges River morphological dynamics on the Indian shad migration and catch in Bangladesh. Results have indicated that the average water level...... because of the changes in width of the river, and the shifting of river bends is quite frequent over the period of time and is more diverse in the upstream region than downstream. The decreased water level and the frequent shifting of the river bends might force the Hilsa fish to restrict their migration...

  4. MyD88 Signaling Regulates Steady-State Migration of Intestinal CD103+ Dendritic Cells Independently of TNF-α and the Gut Microbiota

    DEFF Research Database (Denmark)

    Hägerbrand, Karin; Westlund, Jessica; Yrlid, Ulf;

    2015-01-01

    Intestinal homeostasis and induction of systemic tolerance to fed Ags (i.e., oral tolerance) rely on the steady-state migration of smallintestinal lamina propria dendritic cells (DCs) into draining mesenteric lymph nodes (MLN). The majority of these migratory DCs express the α integrin chain CD103....... Similarly,TLR signaling through the adaptor molecule Toll/IL-1R domain-containing adapter inducing IFN-b and downstream productionof type I IFN were not required for steady-state CD103+ DC migration. Taken together, our results demonstrate that MyD88 signaling in DCs, independently of the microbiota and TNF...

  5. Determinants of the Egyptian labour migration.

    Science.gov (United States)

    Kandil, M; Metwally, M

    1992-03-01

    The objective is to summarize the pattern of Egyptian migration to Arab oil-producing countries (AOPC), to review some factors that are important determinants of labor movement based on theory, and to empirically model the migration rate to AOPC and to Saudi Arabia. Factors are differentiated as to their relative importance. Push factors are the low wages, high inflation rate, and high population density in Egypt; pull factors are higher wages. It is predicted that an increase in income from destination countries has a significant positive impact on the migration rate. An increase in population density stimulates migration. An increase in inflation acts to increase out-migration with a 2-year lag, which accommodates departure preparation. Egypt's experience with labor migration is described for the pre-oil boom, and the post-oil boom. Several estimates of labor migration are given. Government policy toward migration is positive. Theory postulates migration to be determined by differences in the availability of labor, labor rewards between destination and origin, and the cost of migration. In the empirical model, push factors are population density, the current inflation rate, and the ratio of income/capita in AOPC to Egypt. The results indicate that the ratio of income/capita had a strong pull impact and population density had a strong push impact. The inflation rate has a positive impact with a lag estimated at 2 years. Prior to the Camp David Accord, there was a significant decrease in the number of Egyptian migrants due to political tension. The findings support the classical theory of factor mobility. The consequences of migration on the Egyptian economy have been adverse. Future models should disaggregate data because chronic shortages exist in some parts of the labor market. Manpower needs assessment would be helpful for policy makers.

  6. Morphological constraints on changing avian migration phenology.

    Science.gov (United States)

    Møller, Anders Pape; Rubolini, Diego; Saino, Nicola

    2017-04-07

    Many organisms at northern latitudes have responded to climate warming by advancing their spring phenology. Birds are known to show earlier timing of spring migration and reproduction in response to warmer springs. However, species show heterogeneous phenological responses to climate warming, with those that have not advanced or have delayed migration phenology experiencing population declines. Although some traits (such as migration distance) partly explain heterogeneity in phenological responses, the factors affecting interspecies differences in the responsiveness to climate warming have yet to be fully explored. In this comparative study, we investigate whether variation in wing aspect ratio (reflecting relative wing narrowness), an ecomorphological trait that is strongly associated with flight efficiency and migratory behaviour, affects the ability to advance timing of spring migration during 1960-2006 in a set of 80 Eurasian migratory bird species. Species with large aspect ratio (longer and narrower wings) showed smaller advancement of timing of spring migration compared to species with smaller aspect ratio (shorter and wider wings) while controlling for phylogeny, migration distance and other life-history traits. In turn, migration distance positively predicted aspect ratio across species. Hence, species that are better adapted to migration appear to be more constrained in responding phenologically to rapid climate warming by advancing timing of spring migration. Our findings corroborate the idea that aspect ratio is a major evolutionary correlate of migration, and suggest that selection for energetically efficient flights, as reflected by high aspect ratio, somehow hinders phenotypically plastic/microevolutionary adjustments of migration phenology to ongoing climatic changes. This article is protected by copyright. All rights reserved.

  7. Cultural values and international migration

    Directory of Open Access Journals (Sweden)

    Miryam Rodríguez Monter

    2009-05-01

    Full Text Available Immigration is one of the most controversial social issues debated nowadays. It is an undeniable fact that the phenomenon is lived in Europe with concern because of its consequences. People who live and coexist in Europe represent a huge cultural variety. Therefore, social and cultural gaps that can affect the basic values of the western societies seem to be inevitable due to the dimensions of the current migration phenomenon. The present studies are based on the European Social Survey Questionnaire (2002, and the Portrait Values Questionnaire (Schwartz, 1992, 2001 and focuses on the relevance of cultural values to explain the acceptance or rejection of the immigrant.. Finally, we emphasize the importance of cultural values -like Harmony or Egalitarianism- for any initiative or social policy which aimes at reducing the problems concerning inmigration in the European context.

  8. Migration, Transit and the Informal

    DEFF Research Database (Denmark)

    Juul, Kristine

    2016-01-01

    In the last couple of years, Copenhagen has been receiving new types of visitors: young, resourceful men from southern Europe in search of job opportunities. Many are of West-African origin, and have lived many years in Spain and Italy. As a result of the economic recession, they are now moving...... a mix of private charity, collection of bottles and informal odd jobs, moving between the Nordic capitals as opportunities for income generation arise. The emergence of such hyper mobile and flexible proletariat challenges many of our perceptions on migration. Conceptions of integration, citizenship...... northwards. Being Schengen residents, their entry is legal, but obtaining a work permit remains almost impossible. Instead, a wide range of geographical areas are being scrutinized for alternative income opportunities. Therefore, they relapse into a position as modern ‘ hunter-gatherers’ surviving through...

  9. Migration for Labor, Migration for Love: Marriage and Family Formation across Borders.

    Science.gov (United States)

    Sinke, Suzanne

    1999-01-01

    Addresses how marriage and migration interacted using migration to the United States as an example; the key variables determining this relationship were demographics, legal policies, cultural perceptions, and information and technology. Maintains that the influence of an international marriage market affected the migration decisions of women who…

  10. Multipolar migration: the third mode of radial neuronal migration in the developing cerebral cortex.

    Science.gov (United States)

    Tabata, Hidenori; Nakajima, Kazunori

    2003-11-05

    Two distinct modes of radial neuronal migration, locomotion and somal translocation, have been reported in the developing cerebral cortex. Although these two modes of migration have been well documented, the cortical intermediate zone contains abundant multipolar cells, and they do not resemble the cells migrating by locomotion or somal translocation. Here, we report that these multipolar cells express neuronal markers and extend multiple thin processes in various directions independently of the radial glial fibers. Time-lapse analysis of living slices revealed that the multipolar cells do not have any fixed cell polarity, and that they very dynamically extend and retract multiple processes as their cell bodies slowly move. They do not usually move straight toward the pial surface during their radial migration, but instead frequently change migration direction and rate; sometimes they even remain in almost the same position, especially when they are in the subventricular zone. Occasionally, the multipolar cells jump tangentially during their radial migration. Because the migration modality of these cells clearly differs from locomotion or somal translocation, we refer to their novel type of migration as "multipolar migration." In view of the high proportion of cells exhibiting multipolar migration, this third mode of radial migration must be an important type of migration in the developing cortex.

  11. Rural-urban migration in the USSR: problems and prospects.

    Science.gov (United States)

    Zaslavskaya, T I; Korel, L V

    1984-01-01

    Rural-urban migration in the USSR is a cause of social and economic underdevelopment of rural areas, partially a result of the accelerated growth in industry during the 1930s and 1940s that created labor opportunities for the rural populations. From 1927 to 1979 almost 71% of the present population of the USSR moved from farms to cities. The 3 main time spans that characterize these population movements are: 1) the pre-war period, when national industrialization called for labor; 2) the post-war period, which experienced the highest rates of cityward movement due to the hard economic agricultural situation; and 3) the 1960s and 1970s, characterized by a steady, moderately average rate of rural population decline due to a 14% migration rate. Since the early 1970s, policies aimed at preventing this excessive rural exodus, by reducing rural-urban discrepancies and creating compatible rural living conditions with urban ones, have been initiated. To study the inadequacies of rural life that cause rural-urban migration, rural communities were surveyed to determine what types of services are considered disirable and lacking in rural areas. Rural advantages reported are: nearness to nature, peaceful life, opportunity to keep privately formed plots, and the love of farm work, in that descending order. Socioeconomic improvement is needed, and priorities for rural social development should be: 1) close the farm industrial gap in job interest and working conditions; 2) improve educational opportunities for rural youth; 3) provide assistance to private farming; and 4) give more attention to morale in productions teams. The impact of urbanization on rural-urban migration create anticipation of certain changes: 1) spatial mobility of rural populations will grow; 2) the rural-urban exchange will become more equivalent; and 3) social homogeneity of rural and urban societies will increase. however, in order to maintain these favourable shifts in migration trends, it is necessary to

  12. Elucidation of a downstream boundary of the 3' IgH regulatory region.

    Science.gov (United States)

    Manis, John P; Michaelson, Jennifer S; Birshtein, Barbara K; Alt, Frederick W

    2003-01-01

    Class switch recombination (CSR) changes the immunoglobulin heavy chain (IgH) constant region gene (C(H)) in B cells from IgM to IgG, IgA, or IgE, without modifying the variable region gene segment. This process requires transcription through switch (S) regions located upstream of the C(H) genes targeted for CSR, a process that relies on the activity of an uncharacterized regulatory region at the 3' end of the C(H) locus (3' IgH RR) that has been implicated via the effects of pgk-neo cassettes inserted into the locus. The 30kb region just downstream of the most 3' C(H) gene (Ca) contains four known enhancer elements including HS3a, HS1,2, HS3b, and HS4. Replacement of either of the proximal two enhancer elements (HS3a or HS1,2) with a pgk-neo gene cassette disrupted germline transcription of and CSR to most C(H) genes. However, replacement of either of the enhancers with a loxP sequence had no effect on CSR indicating that these elements are not critical for CSR. Insertion of a pgk-neo cassette at various sites within the C(H) locus inhibited CSR to upstream, but not downstream C(H) genes, supporting the notion that the pgk-neo cassette insertion into the locus short-circuits the ability of the 3' RR to facilitate CSR of dependent C(H) genes upstream of the insertion. These analyses also indicated that the key elements of the 3' IgH RR were downstream from HS1,2. In this study, we have sought to localize the 3' IgH RR by defining its 3' boundary. For this purpose, a pgk-neo gene cassette was targeted 2kb downstream of the HS4 element in ES cells that had normal ability to undergo CSR. We then employed Rag-2 deficient blastocyst complementation to generate chimeric mice that harbored B cells homozygous for this mutation. Such chimeras exhibited normal reconstitution of the splenic compartment and had normal serum immunoglobulin levels. Upon in vitro activation, transcription from the pgk-neo cassette was induced in B cells, however, CSR to all measured IgH isotypes

  13. What is the primary driver of downstream connectivity: runoff generation, storage or conveyance?

    Science.gov (United States)

    Ali, G.; Elliott, J.; Lobb, D.; Yarotski, J.

    2013-12-01

    Understanding how headwater streams are connected to downstream areas through the generation and delivery of stream discharge is critical for process conceptualization and hydrological modelling. Several factors have been shown to influence downstream connectivity (DC), notably the location of runoff-generating areas, the mitigating effect of surface depressional storage areas on the delivery of runoff to streams, and the effectiveness of diffuse and concentrated flow paths as runoff conveyance features. Limited efforts have been made to rank these factors in order of importance. Here we aimed to identify the relative influence of runoff generation, storage and conveyance factors on DC in an agricultural Prairie watershed. The 75 km2 South Tobacco Creek Watershed (STCW, south-central Manitoba, Canada) is drained by a 20 km-long creek that drops nearly 200 m in elevation over its course; it is characterized by highly seasonal dynamics such as sheet flow on frozen ground in spring, intermittent flow in summer, and significant surface and subsurface flow events in fall. Hourly discharge records were obtained for seven pairs of upstream-downstream gauging stations within the STCW: for each pair, the magnitude of DC was estimated using cross-correlation values of the two discharge timeseries, while the timing of DC was characterized using cross-correlation lags (in hours or days) to assess the delay of peak flows between upstream and downstream stations. LiDAR data was also used to extract topographic information on: i) the location of runoff-generating areas (i.e., upper-, mid-, low- slope and riparian areas), ii) the area and depth of surface depressional storage basins, and iii) the total length of flow conveyance features (defined streams, all flow paths) in the incremental catchment area between upstream and downstream gauging stations. The computed discharge cross-correlation values indicate that the magnitude of DC is highest in spring, followed by fall then

  14. Migration routes and strategies in a highly aerial migrant, the common swift Apus apus, revealed by light-level geolocators.

    Directory of Open Access Journals (Sweden)

    Susanne Åkesson

    Full Text Available The tracking of small avian migrants has only recently become possible by the use of small light-level geolocators, allowing the reconstruction of whole migration routes, as well as timing and speed of migration and identification of wintering areas. Such information is crucial for evaluating theories about migration strategies and pinpointing critical areas for migrants of potential conservation value. Here we report data about migration in the common swift, a highly aerial and long-distance migrating species for which only limited information based on ringing recoveries about migration routes and wintering areas is available. Six individuals were successfully tracked throughout a complete migration cycle from Sweden to Africa and back. The autumn migration followed a similar route in all individuals, with an initial southward movement through Europe followed by a more southwest-bound course through Western Sahara to Sub-Saharan stopovers, before a south-eastward approach to the final wintering areas in the Congo basin. After approximately six months at wintering sites, which shifted in three of the individuals, spring migration commenced in late April towards a restricted stopover area in West Africa in all but one individual that migrated directly towards north from the wintering area. The first part of spring migration involved a crossing of the Gulf of Guinea in those individuals that visited West Africa. Spring migration was generally wind assisted within Africa, while through Europe variable or head winds were encountered. The average detour at about 50% could be explained by the existence of key feeding sites and wind patterns. The common swift adopts a mixed fly-and-forage strategy, facilitated by its favourable aerodynamic design allowing for efficient use of fuel. This strategy allowed swifts to reach average migration speeds well above 300 km/day in spring, which is higher than possible for similar sized passerines. This study

  15. Robotic assisted laparoscopic colectomy.

    LENUS (Irish Health Repository)

    Pandalai, S

    2010-06-01

    Robotic surgery has evolved over the last decade to compensate for limitations in human dexterity. It avoids the need for a trained assistant while decreasing error rates such as perforations. The nature of the robotic assistance varies from voice activated camera control to more elaborate telerobotic systems such as the Zeus and the Da Vinci where the surgeon controls the robotic arms using a console. Herein, we report the first series of robotic assisted colectomies in Ireland using a voice activated camera control system.

  16. Skilled Migration: Australia. Working Paper No. 63

    Science.gov (United States)

    Shah, Chandra; Burke, Gerald

    2005-01-01

    Migration patterns to and from Australia are becoming complex with migration programmes increasingly targeted towards meeting the needs of the labour market and regional development. This paper provides an analysis of the permanent and temporary movements of people to and from Australia in the last three years and their impact on the skilled…

  17. Spurred by resistance: mechanosensation in collective migration.

    Science.gov (United States)

    Behrndt, Martin; Heisenberg, Carl-Philipp

    2012-01-17

    How cells orchestrate their behavior during collective migration is a long-standing question. Using magnetic tweezers to apply mechanical stimuli to Xenopus mesendoderm cells, Weber et al. (2012) now reveal, in this issue of Developmental Cell, a cadherin-mediated mechanosensitive response that promotes cell polarization and movement persistence during the collective mesendoderm migration in gastrulation.

  18. Kinematics of shot-geophone migration

    NARCIS (Netherlands)

    C.C. Stolk; M.V. de Hoop; W.W. Symes

    2009-01-01

    Recent analysis and synthetic examples have shown that many prestack depth migration methods produce nonflat image gathers containing spurious events, even when provided with a kinematically correct migration velocity field, if this velocity field is highly refractive. This pathology occurs in all m

  19. Intraperitoneal stone migration during percutaneos nephrolithotomy

    Directory of Open Access Journals (Sweden)

    Akif Diri

    2014-12-01

    Full Text Available Percutaneos nephrolithotomy (PNL is the standard care for renal stones larger than 2 cm. The procedure has some major and minor complications. Renal pelvis laceration and stone migration to the retroperitoneum is one of the rare condition. We report the first case of intraperitoneal stone migration during PNL.

  20. Review Fair migration : Setting an ILO agenda

    NARCIS (Netherlands)

    Cremers, Jan

    2014-01-01

    The ILO-report Fair migration is intended to offer an opportunity for tripartite global debate on the migration issue. In his review Jan Cremers admits that the analysis is correct. However, he questions how to make these ideas concrete as workers exploited in a foreign constituency live and work fa